Jetfoil & Large JM Aerofoil Fans For Tunnel Ventilation. FläktWoods

Transcription

1 Jetfoil & Large JM Aerofoil Fans For Tunnel Ventilation FläktWoods

2 Index Contents Section The Company 1.0 Quality Systems & Major Projects Department 1.1 Applications 1.2 Tunnel ventilation methods 1.3 Longitudinal ventilation & fresh air requirements 1.4 Jetfoil Fans 2.0 Jetfoil range overview 2.1 Jetfoil installation 2.2 Jetfoil thrust requirements 2.3 Questionnaire 2.4 Jetfoil selection data 50 HZ 2.5 Jetfoil selection data 60 HZ 2.6 Jetfoil sound data 2.7 Jetfoil test methods 2.8 Jetfoil specification 2.9 Jetfoil installation & maintenance 2.10 Jetfoil dimensions and weights 2.11 Large JM Aerofoil Fans 3.0 Large JM Aerofoil range overview 3.1 Large JM Aerofoil selection 3.2 Large JM Aerofoil selection curves 50 Hz 3.3 Large JM Aerofoil selection curves 60 Hz 3.4 Large JM Aerofoil specification 3.5 Large JM Aerofoil installation & maintenance 3.6 Large JM Aerofoil dimensions & weights 3.7 Additional extra features 4.0 2

3 The Company Fläkt Woods is a leader in the technology of air movement. Our extensive knowledge of designs and applications is based on over 90 years of experience as one of the world s largest manufacturers of fans and fan systems. Fläkt Woods have extensive laboratories where they are constantly developing and testing new ideas and materials enabling them to maintain a position of market leadership. Development programmes include work on aerodynamics, acoustics, vibration, control systems and motor characteristics. State of the art computer modelling techniques are employed at every stage of design to ensure that the end product performs reliably as specified. The manufacturing unit covers an area of some 40,000 square metres and employs around 700 people. Each stage of manufacture is carefully assured by an impressive quality management system approved by major authorities from all over the world. This includes approval as a registered firm to BS EN ISO 9001:1994; the standard for quality assurance systems; and AQAP-1; the standard for the Ministry of Defence. Internationally Fläkt Woods comply with many of the major air moving standards and certification schemes. Fläkt Woods products are marketed and installed in over 100 countries of the world and are utilised in many varied applications which include infrastructure projects, tunnels, metros, building services, light industrial, original equipment manufacturers, and agriculture. Fläkt Woods world-wide coverage is supported by an extensive distribution network, with Fläkt Woods trained advisors capable of providing technical assistance on all applications. Customer satisfaction, attention to detail, reliable delivery and in-service support are the secrets of Fläkt Woods success. Fläkt Woods Head Office and European manufacturing facility 1.0

4 QUALITY SYSTEMS Fläkt Woods Limited is committed to all rotating aluminium components are X- Quality Assurance. Registration to BS EN ISO 9001:1994, means that Fläkt Woods design is quality assured as well as the manufacture. ray examined using real time radiography prior to machining to confirm design integrity, vital when selecting these types of fans. All the Fläkt Woods JM Aerofoils are Our commitment to Quality Assurance fitted with IP55 motors as standard, and doesn't stop with the hardware. The come with a 2 year ex works warranty. performance data comes from standard tests carried out in Fläkt Woods own laboratory which is British Standard (CAME scheme) and AMCA accredited. Those ranges which are AMCA certified are All fans as detailed in this publication are suitable for a one off emergency operation at temperatures up to 200 C for 2 hours (H.T. Category 200/2). Most of Fläkt Woods standard JM Aerofoil fans are identified by the AMCA logo on the independently certified by the Loss appropriate characteristic curve(s). A JM Aerofoil can be bought with the confidence, as with all Fläkt Woods products, that it will achieve the published Prevention Certification Board (LPCB), for emergency use at temperatures of 200 C and above. Many sizes of large JM Aerofoil fans have performance data and match the been independently verified for individual assured quality. An example of the benefit projects. of choosing a Fläkt Woods product is that MAJOR PROJECTS DEPARTMENT Fläkt Woods will serve your needs, simple aspects of cost effective installation design, or complex, large or small. We have lifetime costs, programmed maintenance earned our high reputation by contributing to projects from design to completion, thus and project specification. Your project team at Fläkt Woods ensuring optimum specification and look forward to assisting you in any way we selection of equipment, sustained by Fläkt Woods quality and reliability. Investment in staff training and high levels of competence provides repeated customer satisfaction. can. Either contact our offices worldwide (see website or direct by info.uk@flaktwoods.com. As part of Fläkt Woods Building Services & Projects Division the applications knowledge of the Major Projects Department is freely available to assist you in designing your project in all aspects of Aerodynamic, Acoustic and Electrical performance. The valuable experience from world-wide projects enable Fläkt Woods team to help you with all 1.1

5 APPLICATIONS VENTILATION Ventilation is required for safety and to maintain acceptable temperatures and comfort. Pollution emitted by trains and road vehicles must be removed to provide an acceptable and safe environment. The heat from a train may need to be removed by forced ventilation to ensure that the temperature is acceptable to both people and equipment. In the case of a fire, smoke must be removed to enable safe escape and to assist access to fight the fire. The normal ventilation principles are to dilute pollution and to remove the smoke. The smoke may be removed by creating a reservoir from which it is extracted. Alternatively sufficient velocity is created past the fire to drive the smoke to one side. A14 road tunnel, France - Longitudinal Ventilation by Jetfoils Road Tunnels Road tunnels require ventilation to remove pollution and in case of a fire for the control of smoke. For a long tunnel the pollution requirements normally dominate but for a short tunnel the fire scenario would be the most onerous. Detailed calculations are required to establish the ventilation rate in each case. 1.2 Western Harbour Crossing, Hong Kong, - large JM Aerofoil fans in parallel Longitudinal ventilation is used where possible, as it gives the lowest installation and operating cost. The most common method is to use Jetfoil fans where the relatively high velocity discharge induces a flow of air through the tunnel. As the jet from the fan diffuses, it transfers energy to the tunnel airflow and creates an increase in static pressure, which causes air to flow as in any conventional system. For free flowing traffic in one way tunnels the traffic induced airflow is normally sufficient to ventilate the tunnel even if the tunnel is designed with a fully or semi transverse system. Large axial flow fans are used for transverse and semi transverse systems where the air is supplied or extracted through ducts from plant rooms. Normally several fans are used in parallel to provide steps in volume flow. Frequently the fans are 2 speed to provide additional steps in ventilation, a lower operating cost at low levels of flow and low noise levels for night time operation. Often the fans are 100% reversible so that supply fans can also extract. To clear smoke from one side of a fire, reversible fans may be used with the duct system to create a longitudinal flow along the tunnel. Limehouse Link Tunnel, London - Longitudinal ventilation by There can also be occasions where a longitudinal system using Jetfoils with large JM Aerofoil fans providing Jetfoils is justified in addition to a transverse system as the vertical discharge operating cost at low ventilation rates is much less. To avoid pollution at the portals of the tunnel large fans may be used to capture the tunnel airflow and discharge it at high level.

6 APPLICATIONS Metro & Underground Railways Ventilation is required to remove the heat generated by the trains and other electrical equipment. Virtually all of the electrical power consumed degenerates into heat which is removed by a combination of natural and powered ventilation. During free running conditions the piston effect of the trains may be sufficient for ventilation and natural ventilation may maintain this condition even when the trains are not operating. However, when the system becomes congested and trains are running at short intervals or, in the case of an incident, are stationary with minimum spacing, forced ventilation becomes necessary. The amount of heat generated by trains in rapid transit systems of high density usage is the largest single factor in determining the mass flow of air required to maintain a stable air temperature. However the risk of fire must also be taken into account. Frequently 2 speed fans are used with low speed for heat removal and high speed for fire smoke control. Longitudinal ventilation along the tunnel is common using 100% reversible fans. For an enclosed system large fans connected to atmosphere would be used in a push-pull configuration. If the system is not enclosed Jetfoils can be used to induce the required airflow along the tunnel to and from atmosphere. Smoke is directed in the most favourable direction depending on the position of a fire in the train or tunnel. Fans are normally rated from 150 C to 250 C for 1 hour. Air movement in the stations follows normal ventilation practice as far as possible. For smoke control, supply and extract fans are used, reversible if a longitudinal system is being used. Smoke curtains can be used to create smoke reservoirs. Route 3, Hong Kong - large JM Aerofoil fans suitable for emergency operation H.T. 250/1. For railway tunnels with diesel engines, ventilation may be required to remove the pollution from diesel smoke. Ventilation may also be required to reduce air movement caused by piston effect and thus increase the flow past the train. This avoids having stagnant area around the engine, which may cause overheating. As the resistance of the tunnel is low in relation to a ducted system the effect of wind pressure must be considered. For example, wind pressure could cause the air supplied to the centre of a tunnel to flow in one direction rather than equally in both directions. MRT Woodlands, Singapore - JM Aerofoil H.T. Fans 1.2.1

7 APPLICATIONS Railway Stations Surface railway stations are frequently covered, with open ends. These may provide sufficient natural ventilation for removal of heat but if height is restricted it may be necessary to use powered ventilation in case of a fire. A highly effective way of ventilating this type of station is by installing Jetfoils above the platform at high level, thus creating a longitudinal air flow along the platform. If space is very restricted this system may also be used to remove heat and diesel fumes from the locomotives. Charles de Gaulle Station, Paris mm Jetfoils, for smoke clearance Tunnel Construction Ventilation of tunnels during construction is one of the most arduous applications. It is necessary for the safety of, operatives and machinery. The requirements to be met include the provision of, sufficient fresh air for the people working in the tunnel, removal of pollution from diesel powered vehicles, removal of heat and humidity, and the removal of dust caused by blasting. There are National Standards giving ventilation rates for fresh air and pollution dilution. The fresh air required for heat removal depends on the heat input and the allowable temperature. If the ventilation rate required is too high, cold water cooling systems can be used. The ventilation rate for blasting depends on the rate at which the fumes need to be cleared. The time to clear the tunnel is dependent on the quantity of explosive used. The ventilation system most frequently used is flexible ducting at high level in the tunnel and axial fans fitted as close to the inlet portal as possible. The ducting is used to supply fresh air close to the face, this is particularly important when blasting to ensure that all the fumes are removed. Modern flexible ducting is relatively leak-free if well maintained, a small amount of leakage is not important (except for removal of blast fumes) as it adds to the air in the tunnel. The air becomes progressively polluted as it moves away from the face and increases to a maximum at the portal, so any air added to the tunnel reduces pollution. The pressure drop of the ducting varies with the duct design. It is, Tempi Rail Tunnel runs under mount Olympus, Greece therefore, important to use the manufacturer s relevant data

8 APPLICATIONS As the ducting is flexible, a positive pressure must be maintained inside the ducting to ensure it does not collapse. Ideally all the fans would be installed outside the tunnel, but there is a maximum pressure limit on the ducting. When this pressure limit is reached, some booster fans must be installed a distance along the ducting inside the tunnel. Multi-stage axial fans are ideal for this application. As the length of the ducting is increased, additional fans are used to increase the pressure capability of the fans. Therefore it is only necessary to install the number of fans needed to provide the required pressure, thus reducing operating and capital cost to a minimum. It is normally possible to select fans of a diameter similar to the ducting which gives a very simple installation. The axial fans are light weight but robust and simple to support at high level in the tunnel. Because of the adaptability of contra rotating fans it is not necessary to predesign the ventilation system with 100% accuracy. Fans can be added as required when the actual system pressure drop is known. Aircraft Hangers Aircraft hangers are amongst the largest structures requiring air movement. Ventilation may be achieved by Jetfoils to induce a flow through the hanger rather than using a large ducted system. Underground car park ventilation using Jetfoils Car Parks Fan systems are essential to provide forced mechanical ventilation throughout multi story and, particularly, basement parking areas. Not only is carbon monoxide removal necessary, but the capability of smoke extraction in the event of fire must also be considered. It is usual to use relatively large supply and/or extract fans ducted to atmosphere. Fresh air is normally supplied on one side of the car park, and extracted on the other. Even with a complex ducted system stagnant areas can occur. There are also problems with vehicle exits and entrances, which may short circuit the ventilation system. An effective method of minimising these problems is to use Jetfoil fans either to induce an airflow through the system or to direct the air to the required area. Using Jetfoils may allow the elimination of ducted supply and extract air

9 TUNNEL VENTILATION METHODS There are a number of different types of ventilation systems used for tunnels. These can either be used singularly or in combination. Fully Transverse System A fully transverse system has ducted supply and extract air. The supply is normally at low level, from a duct underneath the roadway, so that the fresh air mixes with the exhaust from the vehicles. The polluted air, which is warmer than the fresh air and therefore buoyant, is extracted at high level, normally through a ducted system above the roadway. As a system this is technically the most exact, because it is not affected by wind pressure on the portals or traffic movement through the tunnel. It would normally only be used on long, congested, two-way tunnels. The cost of the civil construction and the mechanical equipment is high and, when installed, the air distribution needs to be balanced carefully. The fans used would generally be large, fixed pitch, JM Aerofoil fans in parallel and would be switched on and off to control the total volume flow. Additional volume steps and reduced running cost can be achieved by using two speed fans, variable pitch fans or variable speed fans. The fans can be installed with the motor shaft vertical or horizontal depending on the space available for plant rooms. Splitter silencers are usually needed to attenuate noise on both the system and atmospheric side of the fans. The sound level in the tunnel should not normally exceed 95 dba to allow communication even in the event of a fire. On the atmospheric side the environmental conditions must be considered and these apply to the tunnel portals as well as the inlets/outlets from the fan system. Two speed fans can be useful as a means of achieving lower noise levels at night, when ventilation requirements would also normally be lower. Four to six rates of ventilation should suffice with the fans controlled by CO, NO2 or smoke monitoring equipment. With large fans there will be a limit to the number of starts per hour. Usually the fans would be run for at least 15 minutes to allow the motor winding temperature to return to normal. They could then be switched off and immediately back on again if necessary. The fan systems would also be fitted with backdraught dampers so that they can operate in parallel. When a fire occurs in a tunnel, without longitudinal movement of air through the tunnel, it draws in fresh air from either side and produces a plume of smoke and hot gases. The smoke and hot gases, because of their buoyancy, stratify above the fresh air and spread sideways along the tunnel, typically for 300 metres on each side of the fire. 600m Smoke control, fully transverse system After this distance, the smoke has probably cooled sufficiently to lose its buoyancy and so mixes with the fresh air being drawn in by the fire. The principle of smoke control therefore is to extract the smoke before this condition occurs. Clearly the exhaust system extracts air from the correct point, but it may not extract sufficient air to capture all the smoke produced by the fire. If this is the case the volume of air removed from the region at the fire must be increased. Often additional extract points with dampers are fitted to the system. They are opened close to the fire and other extract points closed. If the tunnel is one way, it is preferable to ensure that the smoke and hot gases are blown away from the stationary vehicles to reduce the radiated heat from the gases stratified at high level. To achieve this, the supply and extract fans in different parts of the tunnel can be reversed to create the required longitudinal velocity. The fans can be standard fans that are reversed or fans which are 100% reversible and have the same performance in both directions. Any fan handling smoke and hot gases must be designed accordingly. The most common temperature rating is 250 C for one hour although, for some installations, when the fan is very close to the fire, a temperature/time of 400 C for two hours is required. As an alternative, a water spray system may be used to reduce the air/gas temperature. 2m 1.3

10 TUNNEL VENTILATION METHODS Semi Transverse System A semi transverse system is similar to either the supply or extract system of a fully transverse system. Longitudinal Ventilation Systems In a longitudinal ventilation system, the air movement is along the length of the tunnel so there is no need for distribution ducts in the tunnel. Semi-Transverse (supply) If it is a supply system, then fresh air is supplied at low level and the polluted air exits from the portals. In this case, all the exiting air would be at the maximum allowable pollution level so there is no need for the ventilation rate to be increased. The air ducts can be above or below the road surface or at the side of the carriageways. If it is an extract system, the air is exhausted through a series of grilles at high level and the fresh air enters at the portals. The air becomes progressively more polluted towards the centre of the tunnel. Air extracted away from the centre is not at the maximum allowable level of pollution, so the ventilation rate must be increased to compensate. A semi-transverse system is technically less exact than a fully transverse system. It relies on the longitudinal air movement along the tunnel which will be affected by wind pressure on the portals and by the movement of traffic. The ventilation rate, therefore, has to be increased to take into account the reduction of airflow in a particular direction due to these effects. A semi-transverse system would be used for long, congested, two way tunnels. It may be limited by a maximum velocity at the portals. In such cases it could be used for the end sections of a tunnel with a fully transverse system ventilating the centre section of the tunnel. For smoke control, a semi-transverse system has to operate the same way as a fully transverse system, with extract at high level. If the system is a supply system, then the fans must be reversible and operate in extract mode exhausting at high level with the low level grilles closed off by dampers. Fan installations are similar to those for a fully transverse system but, as there is a longitudinal movement of air along the tunnel, the resulting pressure drop must be added to the pressure drop in the ducted system. Longitudinal The air can enter at one portal and leave at another or be supplied or extracted from various locations in the tunnel. The movement of the air can be induced either using large fans connected to these locations, or by jet fans or by a combination of the two types of fan. A longitudinal system is the first choice where possible, as it is a very simple system to install and commission. The control is also simple with fans switched on and off as required. The system has a lower power consumption as the pressure drop of the ducted system and silencers used in transverse systems are eliminated. The air velocity through the tunnel is very low and so is the pressure drop. Longitudinal systems provide smoke control by supplying sufficient longitudinal velocity to ensure that the smoke is blown to one side of the fire. Obviously this solution on its own is most viable provided the tunnel will be clear of traffic on the downstream side of the fire, this only occurs in single direction tunnels with free flowing traffic. If the traffic is not free flowing or the tunnel has two way traffic flow, some other means of removing the smoke and the gases may be necessary. For example, an emergency extract system could be provided with inlets that can be opened close to the position of the fire. To avoid recirculation between bores, the portals of one way tunnels should be separated, although often, as the fans are selected for a smoke control scenario, a degree of recirculation is allowable for normal ventilation. To avoid recirculation under fire conditions, Jetfoils are often made 100% reversible so that in a fire situation the fans in both tunnels are operated in the same direction. l 1.3.1

11 LONGITUDINAL VENTILATION This system is generally accepted as the designer's first choice for the following reasons: 1. Civil and mechanical costs are the lowest. Analysis of costs on a motorway tunnel show that this method can be one tenth of the cost of a semi-transverse system. 2. Can be readily installed. No plant room required. 3. Simple airflow control by fan switching. 4. Generally lower power consumption since no duct resistance to overcome. 5. Fans can be used for fire smoke control in emergency and all can be rated to operate at up to 250 C for 2 hours. Some are suitable for 400 C (enquire) with a performance reduction. However, there are certain limitations:- 1. The length of the tunnel can be a limiting factor as there is a practical maximum for the air velocity. For safety reasons, the tunnel velocity should be below 10 m/s. Generally, velocities above 7 m/s are rare. 2. This system is not generally satisfactory for tunnels of over 300 metres with urban two-way traffic unless emergency exhaust fans are available for smoke venting and passenger escape routes are provided. 3. Potential fire loads of 100 megawatts and greater may preclude use of Jetfoils where the average air temperature may exceed about 300 C car/hour/lane car spacing - metres Cars/hour/Lane Car spacing cars/ km/ lane Cars/km/Lane 40 0 MAXIMUM TRAFFIC (passenger cars) Vehicle Speed - km/hr 1.4

12 FRESH AIR REQUIREMENTS The fresh air required will depend on the following factors: 1. The specified maximum permitted carbon monoxide (CO) and diesel smoke level. Nitric oxides (NO) are not normally considered to be significant in the UK, the lower emission standards of the USA can Make them dominant. 2. The number of vehicles per hour and the number of diesel vehicles. 3. Speed of the traffic. 4. Gradients. 5. Altitude. In practice, it is generally accepted that the maximum air requirements occur when traffic is heavily congested at a speed of 10 to 15 km/hr. In order to enable designers to carry out basic system sizing Fläkt Woods includes a calculation method based upon that recommended by the Permanent International Association of Roads Congresses (PIARC). Their current publications can be obtained from AIPCR/PIARC LA GRANDE ARCHE, PAROI NORD - NIVEAU PARIS LA DEFENSE CEDEX 04 - FRANCE. Carbon Monoxide Fig 2 and 3 are based on vehicle emission data published in 1987 by PIARC following the XVIIIth World Road Congress. In 1995 at the XXth Congress, lower fresh air requirements were put forward. These reflected the improvements in emission achieved with modern designs of vehicle. It is, however, recommended that where a safe design is required, and where traffic may not be to the latest design, the earlier figures should continue to be used. The recommended CO levels are: Type of Tunnel CO at peak traffic (ppm) Congested traffic or standstill Urban tunnels (used to capacity) daily congestion seldom congested 250 Inter urban tunnels 250 (highway or mountain) Fresh air requirements for CO dilution 100 cars per km at 10 km/hr and at sea level 200 Fresh air requirements for CO dilution 100 cars per km at 10 km/hr at 800 metres altitude 400 m 3 /s per km per lane % +3% Level Gradient -3% -6% m 3 /s per km per lane % +3% Level Gradient -3% -6% Fig Fig 3 Parts per million CO Parts per million CO 1.4.1

13 FRESH AIR REQUIREMENTS Diesel Smoke Figures 4 and 5 are based on diesel vehicle emission data published in 1987 by PIARC following the XVIIIth World Road Congress. Again in 1995 at the XXth Congress, lower fresh air requirements were put forward. These reflect the improvements in emission achieved with modern designs of vehicle. It is recommended that where a safe design is required and where traffic may not be to the latest design, then the earlier figures should continue to be used. The charts are based on congested conditions with 10% of the vehicles being diesel engines having an average weight of 15 Permissible Visibility Limit tonnes. Type of Tunnel Permissible K lim Visibility Limit (m -1 ) Urban tunnel with dense rapid traffic Congested Traffic When K = m -1 THE TUNNEL MUST BE CLOSED Fresh air requirements for smoke dilution 10 trucks per km at 10 km/hr at sea level 200 Fresh air requirements for smoke dilution 10 trucks per km at 10 km/hr at 800 metres altitude Gradient +6% m 3 /s per km per lane 100 Gradient +6% +3% m 3 /s per km per lane % Level -3% -6% 50 Level -3% -6% Visibility limit m -1 Fig 4 Fig Visibility limit m

14 JETFOIL FANS Jetfoil Fan Types The Fläkt Woods Jetfoil is available either as a high efficiency unidirectional, or as a truly reversible Jetfoil which will give approximately equal airflow and thrust in each direction. Quality Assured Engineered to Fläkt Woods own high standards, our design and manufacturing systems also carry BS EN ISO accreditation. Fläkt Woods fans come with a two year ex works warranty as standard. 1.12m Jetfoil on service trolley to provide easy installation and removal Thrust Capability A wide range of thrust is available from eleven sizes, each having a fully adjustable blade angle. With the standard Jetfoil up to 2,100 Newtons is available. Reversibility In reverse emergency only operation, the uni-directional Jetfoil may give 50 to 60% of the forward thrust. Suitability for prolonged use in reverse must be confirmed by Fläkt Woods. The truly reversible Jetfoil, with its unique blade design, gives approximately equal thrust in forward or reverse directions. Performance Testing Both Jetfoils and large JM Aerofoils have been extensively tested in the Fläkt Woods Development Laboratory (BSI CAME Scheme and AMCA accredited) and use ISO5801 and ISO13350 test methods. The thrust, airflow and sound levels have been measured for a range of sizes and blade angles in both forward and reverse directions. Efficiency The purpose designed impellers have unique blade profiles and are fitted with streamlined fairings and motor supports for high efficiency and thrust. A wide range of diameters are offered allowing the optimum size fan to be selected for each project. 2.0

15 JETFOIL RANGE OVERVIEW 11 sizes mm to 1600 mm Jetfoil fans are fully tested, including thrust, volume in accordance with ISO 5801, sound power levels to ISO and ISO Three standard configurations; fan only, one diameter long silencers, two diameter long silencers each side of the fan. Jetfoils are designed and independently certified to EN for emergency operation at elevated temperatures, up to 400 C for 2hours, (please enquire). Impellers have aerofoil section adjustable blades and are balanced to G6.3. All cast from aluminium and x-rayed. Jetfoils are manufactured either from mild steel with a galvanised finish or Stainless Steel. A painted finish (over galvanised mild steel) can also be offered. Manufacturer registered and assessed in accordance with BS EN ISO AIRFLOW Fig 6 Unidirectional AIRFLOW Fig 7 Truly Reversible 2.1

16 JETFOIL INSTALLATIONS The system resistance calculation for pressure loss in a longitudinal tunnel is quite specialised; allowance has to be made for the effects of traffic, the resistance of fixtures and fittings and the effects of wind on the tunnel portals. Jetfoil fans are usually installed in multiples and are spaced along the tunnel. They are often fitted with integral silencers to achieve an acceptable sound level in the tunnel. For night time operation, and to prevent excessive sound levels close to the tunnel portals, it is possible just to run the fans in the centre of the tunnel or to fit longer silencers to the fans close to the portals. Two speed fans could also be used for night time ventilation. Four to six staged levels of ventilation are normally sufficient and this can be achieved by switching fans on or off as required. The flow induced by traffic movement is often sufficient to ventilate the tunnel, this gives rise to low usage of the fans and makes it wise to sequence their operation in order to ensure uniform operating hours. It is important to note that the airflow through the tunnel is due to the pressure rise caused by the fan. The Jetfoil creates thrust by ejecting a jet of high velocity air. As this air decelerates, it transfers its energy to the tunnel flow, causing a pressure increase that is equal to the fan thrust divided by the cross sectional area. This pressure induces the airflow through the tunnel by overcoming the tunnel resistance. The deceleration of the air occurs gradually and if the longitudinal distance between fans is insufficient, the deceleration will be incomplete and the increased velocity will affect the performance of the next set of fans. It is common practice to have ten hydraulic tunnel diameters DH between sets of fans to eliminate this effect. It is not necessary to have the fans uniformly spaced along the tunnel. The air movement is induced by tunnel pressure difference, as long as there is sufficient distance between sets of fans, the fans may be installed as close to the portals as is practical. If space permits inclination of fan assembly or utilisation of flow deflectors, the installed axial distance between fans sets can be reduced or the installation factor improved. Other effects to be taken into account are the air velocity in the tunnel and the proximity of the fan to the walls and ceiling. Fan thrust is measured under still conditions and is due to the change of momentum of the air passing through the fan. If the air is already moving at the inlet to the fan, the change of momentum is reduced. If a Jetfoil is installed close to a wall, then there will be an additional loss due to the friction between the jet and the wall. If the fan is close to a wall and the roof, the effect must be applied for both wall and roof. When selecting Jetfoils, the following guidelines should be followed. Professional advice should be sought for design validations. Select the largest fan that can be fitted. Larger fans give a higher ratio of thrust to both capital and installation costs than smaller fans. For the lowest operating cost, choose a low speed and/or low pitch angle. The ratio of power to thrust is directly related to the fan outlet velocity so for any given thrust requirements, the higher the velocity, the higher the power consumption. Obviously reducing the thrust for a given size of fan increases the number of fans and hence the capital cost. However, using a lower velocity may mean that silencers can be eliminated or reduced in length. Reversible fans are marginally less efficient and slightly noisier than unidirectional fans but they give much greater flexibility in the operation of the tunnel. They allow single way tunnels to be used for two way traffic when required and the normal direction of airflow to be reversed in fire conditions. Finally the space available for fans can be increased by providing local niches in the tunnel roof or installing fans above car only lanes. So when selecting a tunnel ventilation system, use of Jetfoils should always be considered because of the lower capital and operating costs. They can often be used in conjunction with other systems, for example, to provide airflow at the required velocity in case of fire or to provide the first levels of ventilation at reduced operating costs.this type of use can be applied to new tunnels or to upgrade existing tunnels. 2.2

17 JETFOIL THRUST REQUIREMENTS Airflow requirements are usually based on the need to dilute the pollutants produced by the traffic. These can be assessed knowing the maximum permitted carbon monoxide (CO) level and the visibility limits for diesel smoke. Nitrous oxides NO x are now becoming of increasing importance and some legislation also places limits on their permitted concentrations. Where specific levels for any pollutant are not specified then the data published by Permanent International Association of Road Congresses (PIARC) at the XVIIIth World Road Congress in 1987 can be used. When the airflow requirements have been established, it is then necessary to calculate how much thrust must be provided by the jet fans to overcome the resistance of the tunnel in total. This resistance will be made up from the following items: 1.0 Entry and exit pressure losses: The entry and exit loss, pen Ex is normally assumed to equate to about 1.5 times the tunnel air dynamic pressure. With careful design by the use of a streamlined bellmouth opening to the tunnel and gradual diffusion at the exit, these losses can be reduced. p dt = 1 ρ v 2 T 2 where: P dt = tunnel air dynamic pressure Pa v T = average tunnel air velocity m/s ρ = air density kg/m 3 note: v T = q T A T where: q T = tunnel air volume flowrate m 3 /s A T = tunnel cross sectional area m Traffic drag or assistance There will be a drag resistance in a single direction tunnel where the vehicle speeds are lower than the average tunnel air velocity. In a two-way tunnel, the traffic speed in the opposite direction to the tunnel air velocity must also be considered. In recent times it has been recognised that Jetfoil fans can be used in the event of fire for the control of smoke. Depending on the predicted fire size, the resultant drag from a large number of stationary vehicles could be higher than that for moving traffic, when there would be fewer vehicles in the tunnel. Traffic drag loss in a bi-directional tunnel may be approximated as : p DRAG = A C d. v 1. ρ [(N c1 + N T1 ) (v v1 + v T ) 2 - (N C2 +N T2 ) v v2 - v T (v v2 - v T )] A T 2 where: p DRAG = pressure loss due to traffic drag. C d = vehicle coefficient of drag (1.0) A v N C1 N T1 N C2 N T2 v v1 v v2 Pa = frontal area of vehicles (cars 2m 2, trucks 6m 2 ). m 2 = number of cars in tunnel moving against airflow. = number of trucks in tunnel moving against airflow. = number of cars in tunnel moving with airflow. = number of trucks in tunnel moving with airflow. = vehicle speed of traffic moving against airflow. = vehicle speed of traffic moving with airflow. m/s m/s In a unidirectional tunnel the first term becomes zero. 3.0 Ambient conditions At the tunnel entry and exit ambient conditions may differ especially where the tunnel is long and/or the altitude changes as in mountainous environments. There may then be differences in wind velocity/direction, air temperature and barometric pressure, leading to stack effects either adding to or detracting from the tunnel resistance. The difference in barometric pressure at the two tunnel ends, if measured in Pascals is simply added to the system loss. This effect is known as p stack. 2.3

18 JETFOIL THRUST REQUIREMENTS 4.0 Tunnel surface friction, together with the loss associated with suspended fittings such as lighting, road direction signs etc needs to be established. This pressure loss can be calculated from : p L = 1 ρ v 2 T f 2 where : v T = average tunnel air velocity m/s L = length of tunnel m D h = hydraulic diameter m f = friction factor ρ = air density kg/m 3 note : D h = 4A T P T where: P T = tunnel periphery at a section m A T = cross sectional area of the tunnel m 2 The value of f can vary from about 0.02 minimum to 0.04 maximum. It is dependent on the surface roughness of the tunnel surfaces and the size and number of the tunnel fittings. In the absence of information to the contrary, a reasonable figure to use is f = Total Tunnel Thrust - T T The total thrust required from the Jetfoil is numerically equal to the losses in the tunnel : T T = p T A T L D h where p T is the summation of the pressure losses in items 1.0 to 4.0 i.e., p T = p EN EX + p DRAG ± p STACK + p L Jetfoil Fan Thrust To assist in the design of longitudinal ventilation systems by Jetfoil fans, it is convenient to rate them in terms of the thrust applied to the air, which they develop. The basic thrust is equal to the change of air momentum between the fan inlet and outlet. This is the product of the mass air flowrate and the average air velocity at the fan inlet/outlet. N The theoretical fan thrust is given by T m = air density x air volume flowrate x air velocity = ρ q vf v F = ρ q 2 vf N A F where: q vf = fan air volume flowrate m 3 /s v F = average velocity at fan outlet m/s A F = cross sectional area of fan m 2 It should be noted, however, that this formula is only correct for a uniform velocity. The velocity profile at the fan outlet is far from even. The degree of distortion is very much dependent on the fan design particularly the hub to tip ratio on the impeller, the basis on which the blades have been designed (free, forced or arbitrary vortex) effectiveness of fairings, motor obstruction etc. The measured thrust for Fläkt Woods fans as listed on pages 13, 14, 16 and 17 has been obtained from tests carried out in accordance with the forthcoming ISO It varies from between 0.85 and 1.05 times the value of the theoretical thrust. Other designs have been tested with values as low as 0.65 times the theoretical thrust. The total thrust developed by a number of fans in a tunnel is the sum of the individual thrusts. Fans may be located in groups operating in parallel, or in series spaced lengthwise along the tunnel, or any combination of the two. General working rules are that fans in series should be spaced at ten or more tunnel diameters apart. Alternatively the spacing (m) can be taken as equal to the fan dynamic pressure (Pa) 10. Fans in parallel should have a minimum distance between centres of 2.0 times fan diameter. The above rules are of necessity approximate only. More accurate calculations require knowledge of the Craya-Carlet No. Fläkt Woods will be happy to assist in this calculation for detailed tunnel designs. The number of fans required:- N F = T T to the next whole number T i where: T T = Total Tunnel Thrust N T i = Installed Fan Thrust N

19 JETFOIL THRUST REQUIREMENTS When installed in the tunnel the actual thrust transmitted to the tunnel air will be less than that measured under the laboratory conditions specified in ISO Thus : Installed fan thrust T i = T m k 1 k 2 k 3 N k1 is a correction coefficient based on the fact that the tunnel air velocity offloads the fan as compared with still air conditions. This may be obtained from the Fig 8. k 2 is a correction coefficient based on the knowledge that as the fans are eccentrically placed in the tunnel adjacent to one or two surfaces, some of the air will attach itself to the wall and or roof, rather than be directed into the main flow. This effect will be more severe the closer the fans are to these surfaces. Fig 9 is for the case of no inclination i.e., the Jetfoil fan is parallel to the tunnel axis. z = distance of jet axis to tunnel wall or ceiling D F = Jetfoil fan diameter D T = tunnel diameter (can use hydraulic diame- ter for rectangular tunnel too) Effect of Tunnel Air Velocity on Fan Thrust Note: The corner factor applies to a fan installed equal distances from wall and ceiling. The horizontal axis is more complex than most graphs of this coefficient reflecting the effect of both tunnel and jet fan diameters. It is developed from the work carried out for us by South Bank University and is based on the use of Fläkt Woods fans. k 3 as found from Fig 10 is a correction coefficient based on the knowledge that a small Jetfan inclination of the fan can improve the installation performance. A family of curves have been presented for 4 separation factors (note, the separation factor is the horizontal axis on Fig 9). As expected, for the smallest separation, the jet clings to the wall, even at high inclination. The best result from Jetfan inclination is achieved at a separation factor of 0.16, where an inclination of about 7 degrees gives an increase in thrust of 10%. Clearly the optimum inclination angle differs with separation factor, increasing with decreasing separation. Effect of Wall Proximity on Fan Thrust (Jetfoil parallel to tunnel axis) Tunnel Velocity 2 m/s 4 m/s Ceiling m/s 8 m/s 0.90 Corner k 1 10 m/s k Fan Velocity m/s Fig Fig 9 Separation factor (2 z - D F )/(D T - D F ) 2.3.2

20 JETFOIL THRUST REQUIREMENTS Effect of Jet Inclination on Fan Thrust 1.12 Separation Factor (2 z - D F )/(D T - D F ) k Inclination Angle (deg) Other factors which can affect the installed thrust capability are: a) How close the first fan is mounted to the tunnel entry portal. b) How close the last fan is mounted to the tunnel exit portal. c) In immersed tube or cut and cover tunnels, it is common to have limited headroom and to locate fans in areas that are locally heightened i.e., niches. For the typical construction shown in the sketch below and combined coefficient for k 2.k 3 for Fläkt Woods Jetfoils installed with the centre of the discharge on the ceiling line is as follows:- Inclination angle ( ) k 2.k Typical Niche 15% D F 1.5 D F 1.5 D F 2.3.3

21 JETFOIL ROAD TUNNEL QUESTIONNAIRE Fax No: +44 (0) Attention: Projects Division Date: From: Telephone No: Fax: Please fill in answers below, if unanswered Fläkt Woods will use the parameters in italics. 1.0 General 1.1 Length m 1.2 Area m Hydraulic Dia m 1.4 No. of lanes/tunnel 1.5 Direction of traffic (one or two way) 1.6 Altitude m 1.7 Pressure allowance for wind & barometric difference 20Pa 1.8 Type of tunnel (rural/urban) 2.0 Vehicles in tunnel 2.1 Design speed for pollution 10km/hr 2.2 No. of veh/km/lane % Diesel cars % of trucks 10, 20, 30 tonne 10% 15 tonne 2.5 Gradient in tunnel (Ventilation requirement for pollution is normally based on a traffic speed of 10km/hr ie 100 veh/km/lane as being the most severe). 3.0 Emissions 3.1 Average CO emission at design speed and gradient 3.2 Average particulate emissions at design speed and gradient 3.2 Average NO emissions at design speed and gradient. Note: Due to the complexity of PIARC 1995 in calculating these, from the emissions standards, vehicle age and relative mileage (all for a particular country and design year), unless this data is supplied Fläkt Woods can only carry out assessments to PIARC Concentrations to be designed to: 4.1 CO 4.2 Smoke 4.3 NO2 4.4 % Re-circulation 5% 4.5 Ambient levels to be taken into account. 5.0 Fire scenario Design size of fire, MW 50 Minimum tunnel velocity 4m/s 2.4

22 50 Hz UNIDIRECTIONAL RANGE Fan Type Speed rev/min Blade Angle ( ) Thrust (N) Volume Flow Outlet Velocity (m/s) Absorbed Power kw Sound Power dbw 50J F J F J F J D132/ J D132/ J D132/ J D160/ J D160/ J D160/ K D160/ K D160/ K D160/ K D180/ J F J D132/ J D132/ J D160/ J D132/ J D160/ J D160/ J D160/ J D132/ J D132/ J D160/ J D160/ J D160/ J D160/ J D160/ J D180/ J D132/ J D160/ J D160/ J D160/ J D160/ J D180/ J D200/ J D200/ J D160/ J D160/ J D180/ J D200/ J D160/ J D180/ J D200/ J W225/MF J D160/ J D160/ J D180/ J D200/ J D160/ J W200/LFG J D200/ J W225/MF J D180/ J D200/ J D200/ J W225/MF J D160/ J W200/LFG J D200/ J W225/MF N/kW Frame Size Motor Rating (kwo) Sound Pressure db(a)

23 50 Hz TRULY REVERSIBLE RANGE Fan Type Speed rev/min Blade Angle ( ) Thrust (N) Volume Flow Outlet Velocity (m/s) Absorbed Power kw Sound Power dbw 50JTS F JTS F JTS F JTS D132/ JTS D132/ KTS D132/ KTS D160/ KTS D160/ KTS D160/ KTS D160/ KTS D160/ KTS D160/ KTS D180/ JTS F JTS D132/ JTS D132/ JTS D132/ JTS D160/ JTS D160/ JTS D132/ JTS D132/ JTS D160/ JTS D160/ JTS D160/ JTS D180/ JTS D132/ JTS D160/ JTS D160/ JTS D160/ JTS D160/ JTS D180/ JTS D200/ JTS D200/ JTS D160/ JTS D160/ JTS D180/ JTS W200/LFG JTS D160/ JTS W200/LF JTS D200/ JTS W225/MF JTS D160/ JTS D160/ JTS D180/ JTS D200/ JTS D160/ JTS W200/LFG JTS D200/ JTS W225/MF JTS D180/ JTS D200/ JTS D200/ JTS W225/MF JTS D180/ JTS W200/LFG JTS D200/ JTS W225/MF N/kW Frame Size Motor Rating (kwo) Sound Pressure db(a) 2.5.1

24 60Hz UNIDIRECTIONAL RANGE Fan Type Speed rev/min Blade Angle ( ) Thrust lbf/ Volume Flow (cfm) Outlet Velocity (ft/min) Absorbed Power hp Sound Power dbw 50J D132/ J D132/ J D132/ J D132/ J D132/ J D132/ K D160/ K D160/ K D160/ K D160/ K D132/ K D132/ J D132/ J D132/ J D160/ J D160/ J D160/ J D160/ J D160/ J DF180/LA J D132/ J D160/ J D160/ J D160/ J D160/ J DF180/LA J D200/ J D200/ J D132/ J D160/ J D160/ J D160/ J D160/ J DF180/LA J /LFG J D160/ J D160/ J D160/ J D200/ J D160/ J W200/LFG J D200/ J W225/MF J D160/ J DF180/LA J D200/ J D200/ J DF180/LA J D200/ J D200/ J W225/MF J D160/ J D180/ J D200/ J W225/MF J DF180/LA J D200/ J D200/ J W225/MF lbf/ hp Frame Size Motor Rating (hp) Sound Pressure db(a) 2.6

25 60Hz TRULY REVERSIBLE RANGE Fan Type Speed rev/min Blade Angle ( ) Thrust lbf/ Volume Flow (cfm) Outlet Velocity (ft/min) Absorbed Power hp Sound Power dbw 50KTS D132/ KTS D132/ KTS D132/ JTS D132/ JTS D132/ JTS D132/ KTS D160/ KTS D160/ KTS D160/ KTS D160/ KTS D132/ KTS D132/ JTS D132/ JTS D132/ JTS D160/ JTS D160/ JTS D132/ JTS D160/ JTS D160/ JTS D160/ JTS D132/ JTS D132/ JTS D160/ JTS D160/ JTS D160/ JTS D160/ JTS W200/LF JTS D200/ JTS D132/ JTS D160/ JTS D160/ JTS D160/ JTS D160/ JTS DF180/LA JTS W200/LFG JTS D160/ JTS D160/ JTS D160/ JTS DF180/LA JTS D160/ JTS W200/LFG JTS D200/ JTS D200/ JTS D160/ JTS DF180/LA JTS D200/ JTS D200/ JTS DF180/LA JTS D200/ JTS D200/ JTS W225/LFG JTS D160/ JTS D180/ JTS D200/ JTS W225/MF JTS DF180/LA JTS D200/ JTS D200/ JTS W225/MF lbf/ hp Frame Size Motor Rating (hp) Sound Pressure db(a) 2.6.1

26 JETFOIL SOUND SPECTRUM FACTORS Jetfoils with 1D silencers - 50 Fan Speed Type rev/min Unidirectional J & K Truly reversible - forward JTS & KTS Truly reversible - reverse JS & KTS K 2k 4k 8k k 2k 4k 8k k 2k 4k 8k Jetfoils with 1D silencers - 50 Fan Speed Type rev/min Unidirectional J & K Truly reversible - forward JTS & KTS Truly reversible - reverse JS & KTS K 2k 4k 8k k 2k 4k 8k k 2k 4k 8k Additional correction to 1D silencer 2D silencer k 2k 4k 8k Sound Spectrum Forward Reverse k 2k 4k 8k k 2k 4k 8k dbw D silencer D silencer

27 JETFOIL TEST METHODS 1.0 Air Performance The volume flows are measured using complete Jetfoil units, i.e. fan with silencers and bellmouths fitted, but with the inlet bellmouths replaced by inlet measuring cones in accordance with ISO 5801 and ISO Single measurements are taken and correspond to the volume flow close to zero static pressure. The velocities are derived from the area calculated from the inlet/outlet diameter. 2.0 Thrust Measurement To measure the thrust the Jetfoil units are mounted on the test rig shown in Fig 13. The test rig consists of a platform, supported by low friction linear bearings, mounted on a frame. The bearings constrain the movement to the direction of the axis of rotation of the fan. The platform is restrained by a load cell which measures the force exerted by the fan. The rig is installed centrally in a large building to ensure that the circulating velocities are at a minimum and that there are minimal effects due to the proximity of walls, ceilings and floors. The rig is levelled and the force exerted by the fan measured when the thrust and power readings have stabilised. 3.0 Sound Levels The sound levels are measured using the method specified in ISO Part 2 and ISO 3741 by calibrating a semi-reverberant area Semi-Reverberant Sound Test Method with a reference sound source of known sound power level. The reference sound source is positioned and with the sound source operating the sound pressure levels are measured at the positions indicated on the primary and secondary paths to establish that the area is sufficiently reverberant. A correction factor 'K' for the room calibration can then be determined. The reference sound source is then replaced by the Jetfoil and the fan sound pressure level measured at the positions in the primary path. The Jetfoil sound power level (L w ) is determined by adding with the measured Jetfoil mean sound pressure level (L p(m) ), the K factor. L w = L p(m) + K dbw The selection tables show the average sound pressure level on the A weighted scale at a distance of 10m under free field spherical propagation. At a distance of 3m from the fan, the level would be 10dB higher. As an approximate guide for the in-tunnel dba level, 20dBA can be added to the value at 10m. The NR level is 5 to 8 less, e.g. 90dBA is NR85. The sound power level spectrum can be obtained using the sound spectrum correction factor. The data is essential for evaluating the sound pressure level in a tunnel with all the fans running. Fan Thrust Test Rig DIRECTION OF FAN MOVEMENT REFERENCE SOURCE AIRFLOW x 1.5m x 3m x x x x x SECONDARY MICROPHONE PATH TRANSDUCER/MEASURING SYSTEM. LINEAR BEARINGS 1.8m MIN x x x x x PRIMARY MICROPHONE PATH FAN MOVEMENT POSSIBLE 1.8m MIN ALL SURFACES HARD FINISH Fig 12 Fig Note: the fan shall be accurately levelled prior to testing

28 JETFOIL SPECIFICATIONS 1.0 Sizes The standard range of Jetfoils has eleven diameters from 500 mm to 1600 mm. Smaller and larger sizes can also be provided. 2.0 Performance 2.1 All tests shall be performed on complete units with the appropriate silencers or bellmouth(s) fitted. 2.2 The fan shall deliver the volume or velocity specified when tested in accordance with ISO 5801 with a flow measuring inlet fitted in place of the inlet bellmouth. 2.3 The fan shall give the sound power level specified when tested in accordance with ISO and ISO Inlet and outlet sound levels shall be measured and in the case of reversible fans, the sound level shall be measured in both directions of airflow. 2.4 The fan shall give the thrust specified when tested on a test rig which constrains the longitudinal axis of the fan. The test measurements shall be made after the fan has reached steady operating conditions. 2.5 Three standard configurations are available. No silencer, in which case the fans are fitted with bellmouths. One diameter long silencers each side of the fan. Two diameter long silencers each side of the fan. 2.6 Jetfoils are designed for emergency operation at elevated temperatures, typically 250 C for 1 hr. Up to 400 C for 2 hrs are available. Suitability of units to be confirmed by Fläkt Woods Limited. 3.0 Construction 3.1 Impeller The impeller shall have aerofoil section blades fitted to a hub in a manner that allows simple adjustment of blade pitch angle. Blades and hubs will be cast from aluminium-silicon alloy in accordance with EN1676 (similar to ISO 3522 and 7720) Grades EN AB or EN AB The hub shall be fitted with a cast iron or steel insert bored and keywayed. Unidirectional impellers may be fitted with an aerodynamically shaped spinner. All cast aluminium impeller components shall be X-rayed to show compliance with the specified grade of ASTM E155. X-ray records shall be traceable to the components and retained for a period of 10 years. 3.2 Casing Standard The fan casing shall be manufactured from mild steel to EN10111 (similar to ISO 3574 and 3576) Grade HR14 with integral spun flanges. Four radial motor supports shall be used, continuously welded to the casing. The casing assembly shall be hot dip galvanised after manufacture in accordance with ISO 1459, 1460 and/or Stainless Steel (560 mm to 1000 mm) The fan casing shall be manufactured from Stainless Steel to ENXXXXXX Grade 316L (other grades are available) with integral spun flanges. Four motor supports shall be used either bolted or welded to the casing. Smaller and larger sizes can also be provided. 3.3 Silencers Standard Standard construction with pre-galvanised steel outer skin fastened to hot dip galvanised ends and bellmouths, fitted with galvanised perforated liner and aerodynamic pod Heavy Heavy construction with steel outer skin welded to flanges and bellmouth and the complete assembly hot dip galvanised after fabrication, fitted with stainless steel perforated liner and aerodynamic pod Stainless Steel Stainless Steel construction with outer skin fastened to Stainless Steel ends and bellmouths, fitted with stainless steel perforated liner and aerodynamic pod. 4.0 Motor 4.1 The motor shall be pad mounted, continuously air stream rated and complying fully with IEC 34 1, with minimum class F insulation. High efficiency motors also available. The fan shall be fitted with an external terminal box connected to the motor with conduit. Both motor and terminal box shall comply with IEC 34 5 Grade IP The motor bearings shall have an L 10 life of at least 20,000 hours i.e. an average life of 100,000 hours when calculated in accordance with ISO 281. Motors can be fitted with extended lubricators mounted on the fan casing. 4.3 Purpose designed systems of enhanced thermal endurance are offered for emergency operation typically 250 C for 1 hr and up to 400 C for 2 hrs. Bearings shall have a grease suitable for operation at elevated temperatures. 2.9

29 JETFOIL SPECIFICATIONS 5.0 Fan Balance and Vibration 5.1 The impeller shall be statically balanced to a level of G6.3 in accordance with ISO Vibration at the fan feet shall be in accordance with the requirements of ISO 13350: a test performed with the fan supported on anti-vibration mounts, during which the vibration level shall be measured at rotational frequency in the vertical, horizontal and axial directions at a point on the front and rear feet adjacent to the mounting hole. 6.0 Finish Three levels of finish are available. 6.1 Standard finish: steel parts as described under type of construction, impeller unpainted, motor with standard manufacturers paint system. 6.2 Micaceous iron oxide: Grey micaceous iron oxide epoxy paint applied all over with a dry film thickness of 75 microns, to assembled components prior to final assembly. 6.3 External paint finish: Grey epoxy top coat applied to the exterior surfaces of the assembled fan may be specified in addition to (5.1) or (5.2). Other colours can be provided if required. Note: Stainless steel perforated liners shall not be painted. All surfaces shall be pre-treated to ensure good adhesion of paint finish. 7.0 Guards Inlet and outlet guards can be provided. Two types are available, a simple cross or spirally wound from steel wire, both are hot dip galvanised. 8.0 Quality Assurance The manufacturer shall be registered as a firm of assessed ability to produce goods or services in accordance with BS EN ISO Condition Monitoring Most fans can be fitted with condition monitoring equipment to monitor balance levels, vibration levels, bearing temperature or bearing condition Control Panels Panels can be supplied to sequentially control the operation of the fans to give stepped volume control and uniform operating hours

30 INSTALLATION OF JETFOIL When installing a Jetfoil, to minimise risks of resonance due to structural interaction and to accommodate modest misalignment, it is recommended that anti vibration mountings are used. It is important that the natural frequency of the fan on the anti vibration mountings is less than half the rotational frequency of the fan and that the natural frequency of the frame is twice that of the mount. To achieve this, the deflection of the anti vibration mounting in any direction, due to a force equivalent to the weight of the fan, should be at least: 5 mm for rotational speeds of 900 to 1200 rev/min 3 mm for rotational speed over 1200 rev/min The effect of speed control must also be considered. Deflections greater than 10 mm may need special installation methods to prevent excessive movement due to the air movement caused by large vehicles. The deflection of the frame should be not more than 1/4 of the deflection of the Anti- Vibration mountings. The thrust from the Jetfoil is unlikely to give excessive load or movement of the antivibration mountings, but its effect on the support mechanism must be considered as it could cause a high bending load. Similarly any misalignment between the support and the fan could give excessive loads and must be avoided. The positions of the mounting holes in the fan feet are adjustable by means of oversized holes or slots or by packing shims, and this adjustment must be used to avoid misalignment. The safety of the installation should not rely on the isolating spring or rubber, if these fail the fan should not be able to fall. So, for example, if a drop rod is used through the centre of the spring or rubber, a top plate should be used that will not pass through the support. Particular attention should be paid to the potential effects of fire. The use of safety chains independently fastened to the roof of the tunnel is recommended. Advice is available on the design of frames and support systems. A unique design of feet and frames are available that will allow the outer diameter of the fan to be installed on Anti-Vibration mountings and within 25 mm of the tunnel roof, irrespective of the tunnel profile. Fans should always be maintained in accordance with the instructions issued with the product to be installed. 4 FIXING POINTS TO TUNNEL ROOF PER FAN TO SUIT FAN / FEET INSTALLATION NOTE: ALLOW SUFFICIENT GAP BETWEEN FANS FOR ASSEMBLY AND MAINTENANCE 4 SAFETY CHAIN SUPPORTS PER FAN FIXED TO TUNNEL ROOF Fig

31 JETFOIL DIMENSIONS AND WEIGHTS Fan Only IT IS RECOMMENDED THAT A WOODS FRAME ACCOMPANIES THE JET FAN TO ENSURE A SECURE INSTALLATION. L CRS M L CRS Size A B C F J K L M P Weight kg B DIA A DIA J C F J P ANTI-VIBRATION MOUNTS ARE AVAILABLE FOR SOFT MOUNTING INSTALLATIONS. THEY CAN BE MOUNTED BOTH WITHIN THE FRAME, (PICTURED) OR BENEATH THE FOOT, IF REQUIRED Fan & 1D Silencer IT IS RECOMMENDED THAT A FLÄKT WOODS FRAME ACCOMPANIES THE JETFAN TO ENSURE A SECURE INSTALLATION C D CRS H J CRS Size A B C F J K L M P Weight kg B DIA A DIA E F FITTED E G ANTI-VIBRATION MOUNTS ARE AVAILABLE FOR SOFTMOUNTING INSTALLATIONS THEY CAN BE MOUNTED BOTH WITHIN THE FRAME, (PCTURED) OR BENEATH THE FOOT, IF REQURIED Fan & 2D Silencers B DIA A DIA E F K CRS C E P M L CRS Size A B C D E F G H Weight kg

32 LARGE JM AEROFOIL FANS Large JM Aerofoil Fan Types As an addition to their standard JM Aerofoil fans, Fläkt Woods have developed a range of Large JM Aerofoil fans to provide higher pressures and volumes. The fans can be supplied with or without guide vanes, contrarotating and as truly reversible fans, that provide the same flow in both the forward and reverse directions. Size & Performance The Large JM Aerofoil fans have diameters from 1600 mm to 3150 mm and will produce volume flows up to 300 m3/s (600,000 cfm) and 4750 Pa (16 ins wg) total pressure as single stage units. Installation Designs are available for vertical or horizontal installation and the fans are supplied fully assembled and tested. For maximum efficiency, reliability and compactness the fans are direct drive with the fan impeller mounted directly on the motor shaft. Large JM Aerofoil fan being installed prior to an acoustic test Quality Assured Engineered to Fläkt Woods own high standards, our design and manufacturing systems also carry BS EN ISO accreditation. Fläkt Woods fans come with a two year warranty. Reversibility The reversible fans feature a symmetrical reversible blade section that gives the same performance in both the forwards and reverse direction. Performance Testing Both Jetfoils and large JM Aerofoils have been tested in the Fläkt Woods Development Laboratory BSI (CAME Scheme) and AMCA accredited and use ISO 5801and ISO test methods. The thrust, airflow and sound power levels have been measured for a range of sizes, blade angle and in the forward and reverse directions. Efficiency For maximum efficiency either guide vanes or contra rotating fans are available to reduce the lost energy caused by discharging a rotating airstream. 3.0

33 Size range 1.6 m to 3.15 m. Guaranteed performance to ISO Unidirectional or truly reversible blade sections. High pressure 2 stage fans are available. LARGE JM AEROFOIL RANGE OVERVIEW Emergency operation at elevated temperatures (up to 400 C for 2 hours - please enquire). All impeller components are examined by x-ray to ensure extended component life. Manufacturer registered and assessed in accordance with BS EN ISO Ancillaries:- Guards Condition Monitoring Anti Vibration Mounts Flexible Connectors Painted Finish Bellmouth/coned entries

34 LARGE JM AEROFOIL RANGE OVERVIEW Large JM Aerofoil fans of the following types are available. Unidirectional Non Guide Vane These use an impeller designed to operate mainly in the forward direction but which can be reversed occasionally, e.g. in an emergency. To maximise the performance in the reverse direction it does not have guide vanes. A fan of this type would give approximately 65% of the forward flow and about 50% of the pressure development in reverse. Unidirectional Guide Vane If the performance in reverse is less important, fans can be fitted with guide vanes to increase the pressure development. When air passes through a fan the impeller turns the air and gives it a rotating component. The guide vanes turn this component into the axial direction and regain some kinetic energy from the rotating velocity. The performance in reverse would typically be 55% of the volume in the forward direction, with 35% of the pressure. 100% Reversible Fläkt Woods JM 100% reversible fans are designed for maximum performance and efficiency and so have truly symmetrical reversible blade sections. They give 100% reversible performance and about 90% of the volume of a standard fan and 85% of the pressure. The symmetrical reversible section consists of two top surfaces of an aerofoil section back to back in the reverse direction. The top surfaces of an aerofoil section creates nearly all the lift because of the accelerated flow that causes a negative static pressure. Air flow Rotation Rotation Air flow Reversible Section Fig 15 When the fan operates in one direction, the top surface in the forward direction produces its normal lift, although there is an additional drag due to the extra thickness at the trailing edge (which is the leading edge in the reverse direction). When the fan operates in the reverse direction the other surface is now operating in its normal direction and an identical performance is produced. This type of section increases the fan efficiency compared to a fan with alternate reversed blades. Rotation JR (or KL) second stage Blade Air flow Rotation Resultant Air flow Rotation Air flow JL (or KR) first stage Resultant Blade Air flow Rotation Fig 16 Contra Rotating Multi Stage These consist of two or more similar fans operating in series with the impellers rotating in opposite directions. The first impeller rotates the air in one direction and the second impeller rotates it in the opposite direction so that it leaves the fan nearly axially. By this means the contra rotating fan develops more than twice the total pressure of a single fan at a very high efficiency. Volume Control Volume control is not necessarily needed to make a ventilation system operate correctly. It is used to reduce the operating costs of the tunnel and also reduces sound levels. For this reason it is only necessary to have four to six steps of ventilation. Variable Speed This is usually accomplished by the use of induction motors driven by inverters and gives maximum reduction of power with volume, as the power reduces with the cube of volume. However, there is an initial penalty in the additional losses in the motor because the supply from the inverter is not truly sinusoidal and there is the loss in the inverter itself. The latter is an extra heat loss into the plant room that must be removed by ventilation. 3.2

35 LARGE JM AEROFOIL SELECTION The use of an inverter reduces starting current and so gives the best ratio of starting current to starting time. Care must be taken over the design of the system and input and output filters incorporated as necessary to eliminate problems with Elector Magnetic Compatibility and to avoid affecting the mains supply. Larger inverters are also extremely costly, in some cases costing more than the complete fan. Operating at a reduced speed also has the advantage that it reduces, wear of the bearings and the temperature rise of the motor. However the non-sinusoidal wave form does give rise to additional magnetic forces in the winding so the reliability of the winding would not necessarily be improved by this decrease in temperature. The noise level of the impeller will be reduced, by about 17 db at half speed, but additional magnetic noise may be apparent, particularly at the lowest speeds. Consideration must also be given to the life of inverters as, because of design changes, spares may not be available over a long period. Two speed motors provide similar reductions in power consumption without the inherent problems of inverters when limited speed control is required. Variable Pitch A variable pitch fan is fitted with an electric, Pressure 50% 75% 100% Volume Fig 17 pneumatic or hydraulic actuator that enables the fan pitch angle to be changed while the fan is running. The fan volume can thus be reduced by reducing the pitch angle. Again, the first approximation to power saving, is that it reduces by the cube of the change of volume. However the fan is normally selected for high efficiency at the maximum duty point and so as the volume is reduced so is the fan efficiency. The sound level reduces as the volume is initially reduced but can increase again at very low angles when the fan efficiency is very low. Operating at reduced pitch angle and power will reduce the temperature rise of the motor and increase the life of the motor windings. Starting at low pitch angle will reduce the run up time, particularly at reduced voltage. Static Pressure Volume Flow Fans in Parallel Volume control can be most simply achieved by using more than one fan in parallel operation, i.e. the volume is divided between the number of fans used which all operate at the same pressure. The volume is controlled by switching off fans. As each fan is switched off, the volume through the system reduces and so does the pressure. Therefore each invididual fan works against a lower pressure with the result that its volume increases. The power does not reduce totally with the volume cubed as the losses in the parallel part of the installation, the fan, damper and connecting duct work, do not reduce because the volume through this section increases slightly. However, if two speed motors are used with full and three-quarter speeds, the power on the lower speed will be only 42% of that on high speed. Subsequent volume and power reductions can be made from this low level. Other advantages of fans in parallel are that smaller, more standard fans can be used and there is a higher percentage of stand-by in case of a fan system failure. Fan Satic Pressure Low Speed 2 fans High Speed 3 fans 4 fans Air Volume Fig 18 Fig 19

36 MAXIMUM SELECTION CRITERIA Detailed fan selections are available either direct from Colchester or from our local representatives. For design purposes, selections may be made from the envelope selection charts provided in section 3.4. The following table provides details of the fan sizes and maximum speeds shown on the charts. A typical duty and in duct sound level a provided for each fan. The sound level at other duties can be established using the calculation shown below. The motor rating, to adequately provide the selected duty, may be established by the calculation shown below using the following efficiencies. 65% for 100% reversible fans, 70 % for non guide vane fans and 75% for guide vane fans. 50 Hz Unidirectional Fan Max Volume Total Octave Band Centre Frequency (Hz) Sound Dia Speed Motor Flow Pressure Level (m) (rpm) (kw) (m 3 /s) (Pa) K 2K 4K 8K dbw Enq Hz Truly Reversible Fan Max Volume Total Octave Band Centre Frequency (Hz) Sound Dia Speed Motor Flow Pressure Level (m) (rpm) (kw) (m 3 /s) (Pa) K 2K 4K 8K dbw Enq Motor Rating Calculation Motor Rating kw Volume flow m 3 /s x total pressure Pa 10 x Efficiency % After calculating the motor rating, check it is within the rating of the maximum motor for the fan. Sound Level Calculation Sound Level of Fan = Base sound level + 25.log 10 Actual flow x Actual pressure Base flow x Base pressure 3.2.2

37 MAXIMUM SELECTION CRITERIA 60 Hz Unidirectional Fan Max Volume Total Octave Band Centre Frequency (Hz) Sound Dia Speed Motor Flow Pressure Level (m) (rpm) (kw) (m 3 /s) (Pa) K 2K 4K 8K dbw Enq Enq Enq Hz Truly Reversible Fan Max Volume Total Octave Band Centre Frequency (Hz) Sound Dia Speed Motor Flow Pressure Level (m) (rpm) (kw) (m 3 /s) (Pa) K 2K 4K 8K dbw Enq Enq Enq Motor Rating Calculation Motor Rating kw Volume flow m 3 /s x total pressure Pa 10 x Efficiency % After calculating the motor rating, check it is within the rating of the maximum motor for the fan. Sound Level Calculation Sound Level of Fan = Base sound level + 25.log 10 Actual flow x Actual pressure Base flow x Base pressure 3.2.3

38 LARGE JM AEROFOIL Unidirectional SELECTION CURVES 50 Hz , 4P 2000, 4P Total Pressure Pa , 4P 2240, 6P 2000, 6P 2500, 6P 2800, 8P 2500, 8P 3150, 10P 3150, 8P , 6P Volume Flow m /s Truly Reversible , 4P , 4P 1800, 4P 2500, 6P Total Pressure Pa , 6P 2800, 8P 3150, 8P , 6P 1800, 6P 2500, 8P 3150, 10P Volume Flow m /s 3.3

39 LARGE JM AEROFOIL Unidirectional SELECTION CURVES 60 Hz , 4P 1800, 4P 2240, 6P Total Pressure Pa , 6P 1800, 6P 2000, 6P 2240, 8P 2500, 8P 2800, 10P 2500, 10P 3150, 12P 3150, 10P Volume Flow m /s Truly Reversible , 4P 1800, 4P Total Pressure Pa , 6P 2000, 6P 2240, 6P 2500, 8P 2800, 10P 3150, 10P , 6P 2240, 8P 2500, 10P 3150, 12P Volume Flow m /s 3.4

40 LARGE JM AEROFOIL 1.0 Sizes The Large JM Aerofoil fan is available from1.6 m to 3.15 m 2.0 Performance The fans shall deliver the volume and pressure specified in the fan schedule when tested in accordance with, and to the tolerances specified in, ISO Truly reversible fans shall deliver this performance when tested in the forward and reverse directions. The fans shall give the sound levels specified in each octave band when tested in accordance with and to the tolerances specified in, ISO 5136 or ISO A as appropriate. Truly reversible fans shall deliver this performance when tested in the forward and reverse directions. 3.0 Construction 3.1 Impeller Blades The blades shall be cast aluminium alloy. The blade castings shall be x-rayed using real time radiography to standards defined by ASTM E155 and a record of the x-ray retained electronically for a period of 10 years. Paper prints of the x-ray can be provided. The impeller blades shall use an aerofoil section selected for high performance and low susceptibility to fluctuating stresses due to rotating stall, in both the forward and reverse direction. Truly reversible impellers shall use an aerofoil section that gives identical performance in each direction. The blades shall be drilled, tapped and fitted with high strength steel fixing studs. The stud shall be used to fasten the blade through the hub and shall be fitted with a heavy washer and retaining nut on the inside. Alternatively the blades shall be manufactured with a shank to locate in a recess the hub and clamp plate. The blade tips shall be machined to give the minimum clearance between blades and casing Hub The hub shall be of welded construction from structural steel to BS EN S355JR and shall be stress relieved after welding and before machining. Alternatively the hub shall consist of a matching pair of cast aluminium alloy ISO 3522 clamplates with recesses shaped to clamp the blade shank. The hub shall be retained by a single self locking bolt and heavy SPECIFICATION washer to hold it firmly against a shoulder on the motor shaft. The hub spinner shall be spun from aluminium to EN 485 Grade EN AW 1200 and shall be bolted to the hub. 3.2 Casing The fan casing shall be of sufficient length so that the impeller, motor and other parts do not extend beyond the end flanges. It shall be manufactured from mild steel to EN All parts shall be joined by continuous welding using butt or fillet welds as appropriate. Flanges shall be in accordance with ISO 6580 or ISO as appropriate and either integrally spun or continuously welded to the skin. The minimum duct thickness shall be 6 mm. An external terminal box shall be fitted for the connection of electrical leads to the motor windings and a separate terminal box shall be fitted for auxiliary connections. The terminal boxes shall meet the requirements of IEC 34-5, IP55 and shall be fitted with a drain hole at the lowest point within the box. The terminal box shall be connected to the motor by a rigid or flexible conduit. 3.3 Fans with flange mounted motors The motor support for vertically mounted fans shall consist of a cylinder of minimum thickness 8 mm with an end plate of minimum thickness 25 mm to which the motor shall be mounted. The cylinder shall be supported by plate arms of minimum thickness 8 mm. Fans shall be fitted with four support feet fabricated from a minimum of 10 mm thick plate and drilled for anti-vibration mounts. 3.4 Fans with foot mounted motors The motor mounting plate shall be supported by a triangulated M frame constructed of a minimum thickness 10 mm. The fans shall be supported on a frame constructed from a minimum of 150mmx75mm channel with fixing holes for four anti-vibration mounts. Alternatively, fans can be mounted on braced mounting feet with fixing holes for four anti vibration mounts. 3.5 Fans with pad mounted motors For smaller fans, motors shall be pad mounted supported either by bolted in arms or guide vanes welded to the duct skin. 3.5

41 LARGE JM AEROFOIL 4.0 Motor The motor shall be squirrel cage induction type, single or two speed, with class F insulation and class F continuous rating to IEC Alternatively if the fan is to operate at 250 C for one hour in an emergency condition the motor shall have class H insulation to IEC The motor shall be fitted with ball or roller bearings with an L10 life of hours, calculated in accordance with ISO 281. The motor shall be fitted with a gland plate for connection to the conduit to the terminal box. Motors fitted to vertically mounted fans shall be flange or pad mounted. Motors fitted to horizontally mounted fans shall be flange, foot or pad mounted. All flange or foot motors shall be fitted with a metal cooling impeller suitable for use with balance weights for dynamic balancing. The motor shaft shall have a side fitting key and be drilled and tapped for the impeller retaining bolt and be provided with a shoulder to positively locate the fan impeller. Provision shall be made for external relubrication with lubricators extended to the outside of the casing with corrosion resistant nylon tube terminating in a straight fitting protected by a dust cap. 5.0 Fan Balance and Vibration The impeller shall be statically balanced on a balancing machine in accordance with the requirements of ISO After assembly the fan shall be vibration tested to the levels specified in ISO and ISO SELECTION CURVES 60 Hz 6.2 Impeller Steel hubs shall be grit blasted and zinc sprayed to EN Aluminium hubs, blades and spinner shall have no additional finish. 6.3 Motor The motor shall have a two coat epoxy paint finish. 7.0 Guards Inlet and outlet guards can be provided. Two types are available, a simple cross or spirally wound from steel wire, both are hot dip galvanised. 8.0 Quality Assurance The manufacturer shall be registered as a firm of assessed ability to produce goods or services in accordance with BS EN ISO Condition Monitoring Most fans can be fitted with condition monitoring equipment to monitor balance levels, vibration levels, bearing temperature or bearing condition Control Panels Panels can be supplied to sequentially control the operation of the fans to give stepped volume control and uniform operating hours. 6.0 Finish 6.1 Casing The casing of fans up to 2800 mm diameter shall be hot dip galvanised after manufacture in accordance with ISO 1459, ISO 1460 and ISO 1461 as appropriate at a rate of at least 0.61 kg/m2. The casings of fans 3150 mm diameter shall be grit blasted and zinc sprayed to EN

42 INSTALLATION OF LARGE All types of fans benefit from good installation. The following information is intended to help the user to obtain the maximum airflow, lowest noise level and energy consumption from the installed large JM Aerofoil fan. The recommendations are based on data from years of field experience and are offered as a basic guide to correct installation. They are by no means exhaustive and Fläkt Woods service to system engineers and consultants can go far beyond this. If a fan system presents problems in layout, choice of fans or acoustic treatment, Fläkt Woods engineers will be pleased to advise. When installing a large JM Aerofoil, to avoid resonances in the support frame amplifying vibration, it is recommended that vibration isolators are used. If the fan is supported on a rigid concrete plinth positioned on the ground, vibration isolators may not be necessary but otherwise they are advised. In addition to isolating the fan vibrations from the building structure they also isolate the fan from unwanted vibrations. It is important that the natural frequency of the fan on the vibration isolator is less that half the rotational frequency of the fan, also that the natural frequency of the frame is twice that of the mount. To achieve this, the deflection of the vibration isolator in any direction, due to a force equivalent to the weight of the fan, should be at least: JM AEROFOIL reverse it is better to use diffusing cones or transformations instead of bellmouths or conical inlets. The method of servicing the fans must be planned when designing the installation and provision made for removal of motor and impeller and possibly for the fan. Points for attachment of block and tackle should be provided. Overhead rails can be used to lift, turn and remove the fan. Alternatively slide rails in conjunction with rollers fitted to the fan can be used. Access doors should be placed in the duct system, both upstream and downstream of the fan, for inspection and maintenance. Fans should always be maintained in accordance with the instructions issued with the product to be installed. 5 mm for rotational speeds of 900 to 1200 rev/min 3 mm for rotational speed over 1200 rev/min Deflections greater than 10 mm may need special installation methods to prevent excessive movement due to air pressure, particularly when fans are reversed. The deflection of the frame should not be more than 1/4 of the deflection of the mount. Any misalignment between the support and the fan could give excessive loads and must be avoided. Consideration should be given to the inlet and outlet conditions for the fan airflow. The following diagrams illustrate good practice and conditions to be avoided. For truly reversible fans the system resistance must be considered in both directions. To avoid a high loss in

43 INSTALLATION OF LARGE TYPICAL INSTALLATION - HORIZONTAL AIRFLOW JM AEROFOIL ATMOSPHERE SIDE SILENCER SQUARE TO ROUND TRANSFORMATION SECTION SQUARE TO ROUND TRANSFORMATION SECTION SYSTEM SIDE SILENCER FLEXIBLE CONNECTOR FAN FLEXIBLE CONNECTOR AIRFLOW SPRING VIBRATION ISOLATORS TYPICAL INSTALLATION - VERTICAL AIRFLOW ATMOSPHERE SIDE SILENCER SUPPORT STEELWORK FOR ATMOSPHERE SIDE SILENCER AND ATMOSPHERE SIDE TRANSFORMATION SECTION FLEXIBLE CONNECTOR SQUARE TO ROUND TRANSFORMATION SECTION SPRING VIBRATION ISOLATORS FAN FLEXIBLE CONNECTOR SUPPORT STEELWORK FOR FAN AND SYSTEM SIDE TRANSFORMATION SECTION SQUARE TO ROUND TRANSFORMATION SECTION AIRFLOW SYSTEM SIDE SILENCER 3.6.1

44 INSTALLATION OF LARGE Horizontal mounting JM AEROFOIL Fig. 1H. A fan at entry should be connected to the ducting with a flexible connector and vibration isolators should be used. Fig. 2H. A fan within ducting should be connected by flexible connectors at each end mounted on vibration isolators. Vibration Isolators Fig. 3H. For a two-stage fan it is usually necessary to fit vibration isolators at the middle joint as well as at each end. To avoid mechanically transmitted sound and vibration problems fans are normally installed on vibration isolators. Fig. 4H. The arrangement of flexible connectors and vibration isolators for a single stage fan with one cylindrical silencer. Note: 'B' type silencers must be bolted directly to the fans. Silencer Fig. 5H. The vibration isolator arrangements for a single stage fan with a silencer each end. Silencer Silencer Fig. 6H. The vibration isolator arrangement for a two stage fan with a silencer at each end. Silencer Silencer 3D 1D Silencer D Silencer 1.5D Fig. 7H. Fans in parallel should blow into a common plenum chamber. The minimum dimensions of the plenum chamber in relation to the fan dia should be as above. *Note: If C type silencers are used, they should not be located within one fan diameter on the upstream side

45 INSTALLATION OF LARGEJM AEROFOIL Vertical mounting Make sure the support does not restrict access for removal. Silencer Fig. 1V. Support a single stage fan by mounting feet or plates fixed to the upper flange. Fig. 2V. For a two stage fan support at the upper and lower flanges. Fig. 3V. For a single stage fan with silencer below, support at the top of the fan and top of the silencer. Silencer Silencer Silencer Silencer Silencer Silencer Silencer Fig. 4V. The support arrangement for a two stage fan with a silencer below. Fig. 5V. The supports for a single stage fan with a silencer above. Fig. 6V. Supports for a two stage fan with a silencer above. Fig. 7V. Supports for a single stage fan with a silencer above and below. Fig. 8V. Supports for a two stage fan with a silencer above and below. *Note: If C type silencers are used, they should not be located within one fan diameter on the upstream side

46 INSTALLATION OF LARGE Inlets and outlets JM AEROFOIL WRONG A sharp-edged fan inlet orifice reduces fan performance. RECOMMENDED Fit a bell-mouth inlet to the fan. Reversible fans should be fitted with cones of 15 included angle on inlet and outlet. WRONG A flanged fan inlet starves the impeller blade tips of air reducing performance and increasing noise. RECOMMENDED A bellmouth inlet guides air into the impeller blade tips. D 2D D WRONG Avoid obstructions close to fan inlets. Part of impeller is starved of air. RECOMMENDED Allow a space of at least one fan diameter. (D) at the fan inlet. D WRONG Avoid obstruction close to the fan outlet. RECOMMENDED Allow a space of at least the fan diameter. (D) at the fan outlet

47 INSTALLATION OF LARGE Bends, expanders and contractions JM AEROFOIL WRONG Fan performance suffers and noise is increased if a 90 circular section bend of small radius is used. RECOMMENDED Use a square bend with short chord turning vanes. This is also preferable when air flow is in the opposite direction. α α D WRONG Do not use an expander of more than 15 immediately before or after the fan. RECOMMENDED Ideally an expander immediately before a fan should not be more than 15. Flexible connections WRONG Flexible connectors should not be slack, as this will cause "necking", which will starve the impeller blade tips of air, reduce fan performance and increase noise. RECOMMENDED Flexible connectors should be just long enough for mechanical isolation and should be taut

48 DIMENSIONS AND WEIGHTS Horizontal Mounting C E 450 D S HOLES T DIA EQUISPACED ON H PCD IN ALL FLANGES P B DIA OVER FLANGES A DIA INSIDE F L CRS K CRS M Fan A B C D E F K L M P H S T Max Dia MAX MAX CRS CRS PCD Fan Weight (kg) All dimensions in mm 3.7

49 DIMENSIONS AND WEIGHTS Vertical Mounting M OVER MTG BRACKETS L CRS S HOLES T DIA EQUISPACED ON H PCD IN ALL FLANGES C 450 D OVER T/BOX A DIA INSIDE B DIA OVER FLANGES All dimensions in mm Fan A B C D L M H S T Max Dia MAX MAX CRS PCD Fan Weight (kg)

50 ADDITIONAL FEATURES Fläkt Woods are able to provide additional equipment and features to support typical project applications. Please enquire to Colchester for:- Dampers Key to the control and operation of many ventilation systems are control dampers. These should normally be sized on an airway velocity of 8 m/s or below in order to avoid excessive system pressure and excess noise generation. Physical support must be designed in to accept both static and dynamic loading. Attenuators Fläkt Woods has over 40 years experience in noise control engineering and can assess and design attenuators to meet noise requirements on both system and atmospheric sides. Attenuators can be provided as complete units, modules and splitter only to suit concrete shafts and housings. Airways velocity above 8 m/s should be avoided to limit system pressure and noise generation. Vibration/Condition Monitoring Principle operating monitoring systems are available on the fans to minimise risks of breakdown and enable programmed maintenance to be effectively planned. Options include bearing vibration and temperature systems. Bearing condition monitoring and motor winding condition. We will be pleased to discuss the best choice for your application. Motor Starters/Inverter Drives Drive systems can be supplied and specified through Fläkt Woods to match the operating characteristics of the fan drives and ensure compatibility of the complete package. Interfacing with key control and management systems are principle specification requirements. Product Ancillaries Such as inlet cones, guards, flexible connectors and anti-vibration mountings are available and are shown as part of the dimension and weights drawing. After Sales Service Fläkt Woods Service and Repair Division offer a full range of site support activity that includes routine monitoring site surveys and service contracts. Please contact Colchester for further details. 4.0

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52 We Bring Air to Life Fläkt Woods Group provides a full range of products and solutions for buildings ventilation, air treatment and industrial air movement Head office Fläkt Woods Group Ltd Affolternstrasse Zürich Tel: Fax: info@flaktwoods.com Sales Offices available World Wide - See our website for details Due to a policy of continuous development and improvement the right is reserved to supply products which may differ from those illustrated and described in this publication. Certified dimensions will be supplied on request on receipt of order. PC/Corp July 04 DDJRG/1004/JM JET (NEW STYLE)