the membrane to be redesigned in a more rational way to improve its performance.

Transcription

1 Internatioonal Journaal of Sciencce and Reseearch (IJSR R) ISSN N (Online): Iacct Factor (201 12): Anallysis of o Metteringg Pu and Problle So olutionn durring Work W Narendra Mal1, Ja ay Joshi2 1 Studeent of S.P.B Paatel Engineering g College, Gujarrat, India A Abstract: Meteering Pu is introduced herre with its variious key featurees and benefitss. Manufacturiing rocess and d testing roceedure foor etering u u are descriibed in brief. Detailing D of th he robles en ncountered wh hile working an nd its ossible solutions are also entioned here.. An inefficientt u will usee ore energy than t norally required so thiis aer additioonally highligh hts the rocedu ure to in ncrease the effficiency of ettering u u to certain leevel. This aeer addresses eertinent issues involved in etering u and asssociated workiing robles with w solutions. K Keywords: Meetering Pu, Manufacturing, M Proble Solutiions, Efficiency y 1.1 Characterisstics of Meterring Pu 1. Introducttion A etering uu oves a recise voluue of liquidd in a secified tiee eriod rooviding an accurate a flow w rate. D Delivery of fluuids in recisee adjustable flow f rate soeeties caalled eteringg. The ter etering u is based on the alication or use rather thaan the exact kind k of u used, allthough a couule tyes of us are farr ore suitablle than ost other tyes of us. Although etering us can uu water, they are offten used to u che icals, soolutions, or otther liquids. Many M eteringg us are raated to bee able to u into a higgh discharge ressure. They are tyyically adee to eter at flow rates whhich are racctically coonstant (whenn averaged ovver tie) withhin a wide rannge of diischarge (outllet) ressure. Manufactureers rovide eaach of thheir odels of etering uus with a axiu disccharge rressure ratingg against which each odell is guaranteedd to be abble to u against. The etering u T is a ossitive dislaceeent liquid dosing d deevice with the t ability to t vary caaacity anuallly or auutoatically as a rocess connditions requirre. It features a high leevel of reetitiive accuracy and a is caablee of uing a wide raange of che icals includding acids, baases, corrosivves or viiscous liquidds and slurrries. The uing actiion is deeveloed by a recirocatingg iston, whicch either is in direct coontact with thhe rocess fluuid, or is shieelded fro thee fluid byy a diahrag. Diahrag s are actuatedd by hydraulicc fluid beetween the iston and the diahrag. d Thhe basic rincile of w working of eetering u is i siilar to working w of thee heart off huan being. Both alosst erfor sa e functions. Sized too fit the syste conditions, Flow rate adj djustable for varying v coonditions, addjustable for varying reessures, ulsiing or reecirocating action, a check valves, v Leak roof, built in safety feeatures, rugged in constructtion. Figuree 1: Key Featuure of Meterin ng Pu Thee uing acttion is develooed by a recirocating isston. Thiis recirocatinng otion devvelos a flow easily e rereseented by a sine wavee. Actual flow w rate is deeterined by the folllowing forulla: w rate = disllaceent x cycles er unit of o tie Flow Grah 1: Floow Rate vs. Pressure for diffferent uss Paer ID: OCT14985 V Volue 3 Issue 11, No oveber net Licenssed Under Creeative Coo ons Attributionn CC BY 728

2 Unlike centrifugal us, flow rate is not greatly affected by changes in discharge ressure. It tends to reain unchanged neglecting inor losses. Grah.2: Flow Rate to %Setting Grah Characteristic curve is linear. It is not necessarily roortional in that 50% stroke setting ay not equal 50% flow. This is due to the fact that the calibration line ay not ass through 0 on both axes siultaneously. By easuring flow at 2 stroke settings, lotting both oints and drawing a straight line through the, other flow rates vs. Stroke can be accurately redicted. The steady state accuracy of a correctly installed industrial grade etering u is generally + 1.0% or better. Although a etering u can generally be adjusted to u at any flow rate between zero and its axiu caacity, its accuracy is easured over a range deterined by the u's turndown ratio. Most etering us have a turndown ratio of 10:1, which sily eans that the u is within its accuracy rating anywhere between 10% and 100% of caacity. 1.2 Proble Suary and Literature Survey The resent invention is related to study of etering u and solving different robles during work. Locating the Best Efficiency Point for Metering Pu, Best Efficiency Point is the oint where the axiu efficiency can be achieved. An engineer, designer, or user should ensure that the ressure, teerature ratings and wetted u aterials are coatible for the alication and the tye of liquid being ued. Most etering us have a u and a otor. The liquid being ued goes through the u head, entering through an inlet line and leaving through an outlet line. The otor is coonly an electric otor which drives the u head. Giovanni Mii [1] invented the ebrane to searate the rocess fluid fro the oil circuit in etering diahrag us, it is the critical coonent of these achines. Soeties, deending on the oerating conditions, the ebrane ay crack and it is necessary to disasseble the u and relace this coonent art. Design iroveent was done to avoid the crack. The behavior of a ebrane ounted in a etering diahrag u has been siulated by using FEM. An accurate analysis of the result has allowed the ebrane to be redesigned in a ore rational way to irove its erforance. Donelle Cariotti [2] of Wanner Engineering suggested that a new definition is required for etering u, with recent technical develoents and additional caabilities. Robert S. Ruggeri and Royce D. Moore [3] investigated a ethod for rediction of u cavitation erforance for various liquids, liquid teeratures, and rotative seeds. Both exeriental and theoretical data was obtained. Peter Woias [4] investigated the Probles related to icro us during running. As the ast, rogress and future asects of icro u were studied. Dennis Parker [5] studied about the etering us and about cavitations in a fluid etering u. The syste is having recirocating us as first fluid dislacer and a second recirocating u as second fluid dislacer. The invention also rovide a etering u including a threediensional, variable rofile conjugate cas with a transission stroke odulation assebly that erits conversion between silex and dulex u configurations. The syste revents fluid flow across the u during non-oerational eriods. Barron Dan [6] worked in bosch gbh robert his invention relates to a etering u ade of lastic, with two rotors couled to one another via gears and drivable in oosite directions, which are laced in a u housing equied with suction orts and outlet orts. Each rotor has two rotor blade walls arranged diaetrically on the rotor shaft. A artially cylindrical rotor blade shoe being fored at each of the eriheral ends of rotor blade walls, wherein the rotor blade shoes on the one hand contact the cylindrical inside wall regions of the u housing and on the other contact the rotor blade shafts of the adjacent rotor in a sliding and sealing anner. Eric C. Van bork [7] who worked in ulsafeeder inc. has studied about couter oerated etering u. The dislaceent of a etering u is accurately onitored using a osition sensor connected to a iston. A control couter receives the sensor signal as well as a desired uing volue rate. The ued volue is continuously onitored by the couter as a function of the iston dislaceent and coared with the desired rate. The etering u is controlled to bring the ued volue rate into agreeent with the desired voluetric uing rate. Lonnie G. Wood [8] invented an anti-cavitation device for centrifugal us and ore articularly to a device for allowing air bubbles contained in the liquid in the ie line connected to the suction side of the u to escae fro while aintaining a ositive head of liquid on the suction side of the u. In the uing of solutions or slurries, such as aqueous slurry of hoshate ore, air bubbles soeties becoe entrained in the liquid being ued. Moreover, the ressure dro within the ie line connected to the suction side of a u often causes cavities of air bubbles to for in the liquid in the ie line due to the Paer ID: OCT

3 release of dissolved air, this well-known henoenon being tered cavitation. Moreover, cavitations results in ieller vane itting and corrosion-fatigue failure of etal u arts. The eliination of cavitation within the ie line and u casing greatly increases u efficiency and greatly reduces u wear and u aintenance. Moreover, as anti-cavitations device aintains a ositive liquid ressure on the suction side of the u at all ties. Pu efficiency is increased and the u never loses its rie. 90% of calculated flow rate at 10,25,75 and100 ercentage of stoke length with resect to working ressure of u Linearly of flow rate at different stoke length Reeatability of flow rate at different stoke length Zero flow at zero stoke length Nuber of stoke er inute Leakages Noise of ower end and non-return valve ainly Carl L. Haonds [9] of Haonds Technical Services invention is to rovide a large, very slow oerating echanically oerated valve with suberged suction that allows a u to oerate at virtually any seed fro zero to axiu while eliinating loss of efficiency of rior valves due to cavitation or leakage through their oorly seated valves. The invention is about a u with uch greater control of the delivered fluid by owering the u with a otor with recise control of its seed of rotation and to rovide a u with uing chabers of any stroke length or diaeter. Another object of the invention is to reduce or eliinate the roble of various fluids becoing air-locked within the uing head due to boiling, off gassing, or entrained gas within the fluid being ued. The objects identified above as well as other features and advantages are incororated in a ositive dislaceent u designed to accurately eter various liquids of widely varied viscosities. 3. Efficiency Test for Different Model of Metering Pu For the ractical urose calculation was done for u caacity with the u odel 1125 having lunger diaeter = 20 Stroke length= 20 Pressure Setting =38 kg/c 2 Vessel size = 100 litre The u was attached with the vessel of 100 litre. This got filled in 2 hour 56 inute. That eans er hour caacity of above secified u is 34.2 litre/hr = 34 litre/hr. By this ractical Caacity of any u can be easured. Then the coany rovided the catalogue which had caacity of different odels of u included in it. Hence as a research task calculation for different u was done with the forula as below, Jay Joshi, Manthan Thakkar and Sahil Vora [10] researched about roduction rocesses with grey relational analysis. MINITAB16 software was used to find out regression equation and analysis grahs. 2. Production Process for Metering Pu 2.1 Testing Procedure for Metering Pu Where, V stroke = Stroke volue in litre N = Strokes er inute d = Plunger diaeter L = Stroke length ƞ vol = Voluetric efficiency 3.1 Efficiency of Metering Pu Table.1: Efficiency Test for 1125 Model 1125 (Low Caacity Plunger diaeter SPM Caacity Pressure Efficiency % % % % % % % % % % % % % % Quality assurance deartent assure following areas in each and every etering u: Paer ID: OCT

4 M ain Effects Plot for Efficiency Data M eans Plunger diaeter SPM Mean Caacity Pressure Table 2: Efficiency Test for 1750 Model 1750 (High Caacity Pu) Plunger diaeter SPM Caacity Pressure Efficiency % % % % % % % % % % % % % % Grah 3: Main Effect Plot for efficiency (1125 Model) Efficiency (1125 Model) = (Plunger diaeter) (SPM) (Caacity) (Pressure) Efficiency (1750 Model) = (Plunger diaeter) (SPM) e (Caacity) (Pressure) 3.3 Net Positive Suction Head Concet Net Pressure Suction Head is the total inlet ressure, stated in eters head inus the vaour ressure of the liquid in eters. NPSH can be calculated by deterining the difference between Positive Heads and Negative Heads. NPSHA= H + Hst - Hv - Hfr Ha Main Effects Plot for Efficiency Data Means Plunger diaeter SPM Mean Caacity Pressure Grah 4: Main Effect lot for efficiency (1750 Model) Figure 2: The NPSH Concet 4. Metring Pu Working Probles and Possible Solution 3.2 Regression Analysis Equation By use of MINITAB 16 software 4.1 Different Probles Encountered during Working of Metering Pu Cavitations Over-Delivery Paer ID: OCT

5 Pu does not build ressure just by starting it. Pus deliver higher caacity than secified on the naelate Vortexing Syhoning effect 4.2 Cavitations International Journal of Science and Research (IJSR) The basic definition of Cavitations is the foration of an ety sace within a solid object or body, the foration of bubbles in a liquid, tyically by the oveent of a roeller through sace. Cavitations occur when the u suction is under a low ressure/high vacuu condition where the liquid turns into a vaour at the inlet of the u. This vaour is carried over to the discharge side of the u where it no longer sees vacuu and is coressed back into a liquid by the discharge ressure. This iloding action occurs violently and attacks the u rotors, gears etc. Rotors, screws, gears, etc. that have been oerating under a suction cavitation condition have large chunks of aterial reoved fro their faces causing reature failure of the u. In this case the suction ressure required is quite high, which causes the roble of cavitation due to vacuu ressure created for suction. This reduced suction ressure causes the vaourization teerature also to be reduced. Hence the fluid converts into vaour bubbles in the suction side ie at the roo teerature itself. These vaour bubbles burst when assing through high ressure delivery line. This roble of cavitation causes the fluctuation of delivery and also itting of the ies. To eliinate the roble of cavitations, the suction lift has to be reduced. To reduce the suction lift, the u has to be located on a lower level and near to the base of the tank to get advantage of ressure head. (Increase in NPSH) If the suction ie is drawn out fro above the tank then it creates air tras in the vertical loo, hence it is only required to take the suction line out fro the base of the tank only. 4.3 Over delivery Discharge side iing (Eliinating Over delivery and overflow) the delivery side iing should be designed such that over-delivery should be avoided. When over-delivery haens the delivery side ressure increases due to increased delivery level. This causes an increase in the requireent of the u work due to high ressure requireent. Along with the increased back ressure, this causes severe ressure rise in the delivery line. This can cause the bursting of the ies and daage to the equient. To avoid this ressure relief valves should be rovided, so that the increased back ressure can be released and the u can continue working within erissible ressure liits. In the last case, to avoid the overflowing of the fluid, syhoning effect is used. In this case the fluid fro the reservoir tank is sucked u to a level above the delivery tank, therefore creating a steady fluid flow in the downside suction line and the delivery line. a) Pu is not develoing ressure Pu does not build ressure just by starting it. Pu discharge line ust be contacted to elevated ressure oint to build ressure of discharge side. If still u does not generate ressure or deliver desired flow, check u discharge and suction valve for dirt and foreign articles. b) Pu delivers Higher Caacity than Secified on nae late Ensure that discharge ressure is always greater than suction ressure, if these conditions do not fulfill then u will deliver higher flow than secified on naelate. There should be soe aount of ressure difference between suction and discharge. c) Vortexing Soething is wrong with the u! It s sucking in slugs of air. This reark is frequently ade when vortices for in flow atterns, causing loud rubling noises. A vortex is a whirlool caused by a cobination of factors such as su design, inlet velocity, direction and flow, subergence, and the osition of the bowl assebly in the su. Air entering the u through these vortices causes noise and vibration, but not cavitation. Various ethods can be used to revent vortices. These include using suction ubrellas, lowering the inlet velocities in the su, increasing subergence and relocating us. d) Syhoning Effect The effect is exactly the sae if a Pu is connected to a long discharge ie which falls below the level of stored water i.e. the sensor reservoir. Once the u has begun the rocess of uing the water and the colun of water has ast the oint where gravity takes over the water will continue its journey to the end of the discharge tube even when the u is switched off so draining all the reaining water. The next tie the u is signaled by the sensor to energize it has to u air out to bring water to the internal uing echanis. This can be noisy for a few seconds until water coletely fills the u, this reeated any ties in a few hours can be both very irritating and very wearing to the u literally. The u starts to wear out its internal arts, the result is it takes even longer to rie, ore wear takes lace the u then gets even louder, very soon it fails coletely. It is ossible to sto this effect in several sile ways and kee the u fro being noisy and failing reaturely. 1) Install the etering u so no syhoning can occur by routing the discharge line to a drain oint level with the u reservoir or even above the u. 2) Install the discharge line into a fixed drain line such as 20 PVC overflow ie to create an air break level with the u reservoir, where the drain is at ground level. 3) An Anti Syhon Device is a secial device which can allow a sall aount of air into the discharge line in a controlled way, this effect is only resent when syhoning is actually occurring, at all other ties it reains inactive, this device then is a assive device within the syste sensing when the effect of syhoning is starting and assively reventing this unwanted effect. Paer ID: OCT

6 This little device will take away the roble of syhoning and colaints about noisy etering us once and for all. 5. Result and Conclusion Efficiency of etering Pus is greater than Centrifugal Pus and Rotary Pus. In this dissertation work voluetric efficiency for different odels of u was calculated which are available at Swelore Engg. Pvt. Ltd. Proble of Cavitations can be solved by reducing the suction lift. To reduce the suction lift, the u has to be located on a lower level and near to the base of the tank to get advantage of ressure head (Increase in NPSH). The roble of Over- Delivery can be solved by the use of the relief valve and by the aking the arrangeent of ie in such a way that it creates a syhoning effect. In this effect the fluid fro the reservoir tank is sucked u to a level above the delivery tank with creating a steady fluid flow in the downside suction line and the delivery line. Best Efficiency Point (BEP) for 1125 Model can be achieved at 93.23% with Plunger Diaeter of 10, SPM of 100/in, and caacity of 8 Pressure of 38 kg/c 2. Best Efficiency Point (BEP) for 1750 Model can be achieved at 94.20% with Plunger Diaeter of 10 SPM of 100/in Caacity of 10 Pressure of 290 kg/c 2. Pu efficiency can decrease significantly when the u is oerating away fro the designed Best Efficiency Point. Metering u seed adjustents are the ost efficient eans of controlling flow. Reducing the seed eans less energy is iarted to the fluid and less energy needs to be throttled or by- assed. There are two riary ways of reducing the seed: Multile-seed u otors and using Adjustable seed drives (ASDs). Multile-seed otors contain a different set of windings for each otor seed; consequently, they are ore exensive and less efficient than single- seed otors. Multile-seed otors also lack subtle seed-changing caabilities within discrete seeds. In contrast, ASDs allow seed adjustents to be ade over a continuous range, avoiding the need to ju fro seed to seed. ASDs control u seeds using several different tyes of echanical and electrical systes. Mechanical ASDs include hydraulic clutches, fluid coulings, and adjustable belts and ulleys. Electrical ASDs include eddy current clutches, wound-rotor otor controllers, and variable frequency drives (VFDs). VFDs adjust the electrical frequency of the ower sulied to a otor to change the otor s rotational seed. VFDs are by far the ost oular tye of ASD. In alications with high static head, slowing a etering u could induce vibrations and create erforance robles that are siilar to those found when a u oerates against its shutoff head. For systes in which the static head reresents a large ortion of the total head, however, user should use caution in deciding whether to use ASDs. User should review the erforance of ASDs in siilar alications and consult ASD anufacturers to avoid the daage that can result when a etering u oerates too slowly against high-static-head conditions. Grah 5: Seed Variation and Efficiency Change For any systes, VFDs can hel to irove etering u oerating efficiency desite changes in oerating conditions. The effect of slowing etering u seed on oeration is illustrated by the three curves in Grah 5.When a VFD slows a etering u, its head/flow and brake horseower (bh) curves dro down and to the left, and its efficiency curve shifts to the left. This efficiency resonse rovides an essential cost advantage, keeing the oerating efficiency as high as ossible across variations in the syste s flow deand can reduce the energy and aintenance costs of the etering u significantly. VFDs can also be used with ositive dislaceent us. One ajor benefit of VFDs is that they can reduce energy losses by lowering the overall syste flow or head. By slowing down the u and reducing the aount of fluid energy iarted to the syste when it is not needed, VFDs offer substantial savings with resect to the cost er gallon of liquid ued. Another syste-related benefit is that VFDs rovide a soft-start caability. During start-u, ost otors exerience in-rush currents that are 5 to 6 ties higher than noral oerating currents. This high current fades when the otor achieves noral seed. VFDs allow the otor to be started with a lower start-u current usually only about 1.5 ties the noral oerating current. This reduces wear on the otor and its controller. By reducing a u s oerating seed, a VFD often shifts the BEP to the left of the BEP corresonding to the u s noral oerating seed. In these cases, since the bearing loads on a u are lowest when the u is oerating at its BEP, this shift of the BEP during eriods of low flow allows the u to oerate with lower bearing loads and less shaft deflection. Consequently, using a VFD can extend the interval between bearing aintenance tasks. 6. Future Scoe As is known, there is always soe future scoe of any Research work. For the resent work, the futuristic roosal of work to be included is suarized as under. Here in this Present work, secified etering us were analyzed for efficiency, for future scoe different caacity and different us can be analyzed for different outut factors. Paer ID: OCT

7 Different aroaches and rocedures can be used to solve the working robles of etering u. Different ethods can be used to irove the efficiency of etering u. References [1] Mii, Giovanni, and Paolo Pennacchi. "Diahrag design iroveent for a etering u." Engineering failure analysis 8, no. 1 (2001): [2] Cariotti, Donelle. "Re-defining the concet of a etering u." World Pus 2006, no. 481 (2006): [3] Ruggeri, Robert S., and Royce D. Moore. Method for rediction of u cavitation erforance for various liquids, liquid teeratures, and rotative seeds. National Aeronautics and Sace Adinistration, [4] Woias, Peter. "Microus ast, rogress and future rosects." Sensors and Actuators B: Cheical (2005): [5] Parker, Dennis. "Metering Pu." U.S. Patent Alication 13/230,032. [6] Dan Barron, Metering u ade of lastic. Publication no.: WO A1. [7] Van Bork, Erik C. "Couter controlled etering u." U.S. Patent 5,056,036, issued October 8, [8] Wood Lonnie G, Pu anti-cavitation device., U.S. Patent Alication Publication no.: US A [9] Haonds, Carl L. "Metering u." U.S. Patent No. 7,278, Oct [10] Joshi, Jay, Manthan Thakkar, and Sahil Vora. "Paraetric Otiization of Metal Inert Gas Welding and Tungsten Inert Gas Welding By Using Analysis of Variance and Grey Relational Analysis." Work 240.8: Author Profile Narendra Mal received B.E. in Mechanical Engineering fro S.P.B Patel Engineering College, Mehsana, Gujarat in His areas of interest are Theral & Fluid systes, Manufacturing Systes. Jay Joshi received B.E. in Mechanical Engineering fro S.P.B Patel Engineering College, Mehsana, Gujarat in He has ublished a research aer in International Journal in the field of Otiization of Production Processes. Paer ID: OCT