INSTALLATION INSTRUCTIONS FOR FUME SCRUBBERS

Transcription

1 The scrubber and its components are manufactured out of PVC, polypropylene and acrylic. Gaskets are typically EPDM and Viton. Any chemicals fed into the unit, whether as a scrubbing fluid or as fumes being scrubbed, must be compatible with the materials of construction. The fasteners and pump stand are all constructed of stainless steel. It is recommended that any fasteners used during installation also be stainless steel. NOTE: Always dispose of spent scrubber liquid properly. Use proper safety equipment and follow your company s guidelines for handling chemicals during scrubber fluid changes and when performing any work on the unit. Installation and maintenance should always be performed by properly trained personnel. Foundation The unit should be installed upon a completely level and stable foundation using at least every other bolt hole in the octagon base for securing the base to the foundation. These foundation stipulations are requirements should Salco Field Service personnel be commissioned to perform the install. If the foundation is not completely level, it is recommended that the scrubber base be mounted on anchor studs with nuts screwed on in between base and the foundation. These nuts should be adjusted such that the scrubber body is made level. The base should then be shimmed or grouted at all locations where the base does not touch the foundation. This will ensure that the entire base is completely supported. It is critical to shim and grout your foundation to make it conform to the exact shape of the base. The nuts securing the base to the foundation should only be snug. NEVER tighten a nut or bolt to pull the base to fit a foundation! Upon delivery of the scrubber, some warping or creeping of the base may have occurred and should be expected. NOTE: Scrubbers do not substitute or replace vacuum breakers or pressure relief devices. Vacuum breakers and pressure relief devices must be incorporated appropriately as if the scrubber were not present. See note regarding pressure & vacuum relief near the end of this document. Installation 1. Carefully uncrate the unit. 2. Fasten to a suitable foundation taking all precautions described in the above section. 3. If present, remove the protective tape from the fume inlet flange and install the incoming fume piping. Piping plumbed to the fume inlet must not have any low spots. Low spots will flood with fluid. The lowest spot in the piping should be at the fume inlet itself. 4. If present, remove the protective tape from the exhaust flange and bolt on the exhaust stack. If the unit has a blower, an exhaust stack will not be included. Blowers should not be secured to foundations until they have been plumbed to the scrubber lid scrubbers come with an integrated liquid tank. Plumb the recirculation pump & piping according to the CAD prints. Mount the pump adjacent to the scrubber base in a location that facilitates plumbing to and from it and 30 scrubber come with a stand-alone tank. Mount the tank in a location suitable for plumbing to and from it. It is preferred that the tank be mounted closer to the scrubber rather than further away. If desired, the tank may be secured to its mounting location with straps and turnbuckles. Use caution when using straps on insulated tanks. The insulation must not be crushed. Plumb the recirculation pump & piping according to the CAD prints. Mount the pump adjacent to the scrubber base in a location that facilitates plumbing to and from it. NOTE: Check the inside of the liquid tank for debris (plastic shavings, etc.) prior to plumbing it. Rinse out all debris with water. Debris can plug the recirculation pump and/or the shower nozzle. 7. If the unit has a chemical neutralization system, install it according to the CAD prints. Choose a suitable location to mount the dosing pump. See note regarding ph probes at end of this document. Page 1 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

2 8. If the unit has a manometer, install it according to the following instructions: NOTE: The purpose of the scrubber body manometer is to measure the pressure differential across the bed of packing inside of the scrubber. Manometer Installation onto the Scrubber Body: a. Follow the instructions included with the manometer (#1221) for filling the manometer with the gauge fluid. b. Attach the filled manometer to the two mounting blocks on the scrubber body (See Figure 1) using the supplied #10-24 x stainless steel screws. NOTE: Some assemblies are supplied with #8 x 1/2" titanium screws that can mount directly to the scrubber body. Use these screws if the mounting blocks are not present. c. Apply pipe thread sealant to the threads on the 90 elbow barbs and thread them into the ½ NPT holes which are located on the side of the scrubber body above and below the scrubber packing. Be sure to orient both hose barbs toward the manometer as shown in Figure 2. d. Slip 1 of the hose over one of the manometer ends and cut length to reach the upper hose barb while making sure there are no kinks or flattened sections of hose. e. Place two loose hose clamps on the hose and push the hose onto the barb. f. Tighten one hose clamp on the manometer end and one on the hose barb end. g. Slip the remaining hose over the other manometer end and run the hose to the lower hose barb cutting off any excess and making sure there are no kinks or flattened sections. h. Place the remaining two loose hose clamps on the hose and push the hose onto the barb. i. Tighten one hose clamp on the manometer end and one on the hose barb end. j. Installation is complete. Follow manometer manufacturer s instructions on how to take a gauge reading. Figure 1. Mounting Blocks Figure 2. Manometer Assembly Page 2 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

3 9. Install all of the electronics that came with the scrubber (conductivity probe, ph probe, conductivity/ph analyzer box, paddle wheel flow meter, paddle wheel flow meter analyzer box, etc.). See the section regarding electronics at the end of this document. Analyzer boxes will be panel-mount unless it was specified by the customer otherwise. NOTE: If using the Rosemount ph probe on a horizontal run, the probe must be installed at least 10 above horizontal. (The body of the probe must make at least a 10 angle with horizontal.) 10. Run power as necessary to the motor(s) and electronics(s). Refer to the manufacturers installation procedures. 11. Fill the scrubber liquid tank 3/4 full with scrubbing liquid. If a chemical neutralization system is present, fill the tank only half-way to start. Experience will dictate proper fill level thereafter. 12. If using a chemical neutralization system, fill your neutralizing chemical storage reservoir with the appropriate neutralization fluid. Be sure the chemical you use is compatible with the scrubber s materials of construction and any other chemicals in the area! Note that the Salco ph analyzer box set up instructions assume that the scrubbed fumes are acidic and that the neutralization fluid is alkaline. 13. See attached instructions for proper programming of the analyzer boxes. For the paddle wheel analyzer boxes, refer to the GF Signet website for set up instructions. 14. Heat trace & insulate the entire scrubber system as necessary. 15. Be sure that the three-way valve on the pump assembly is set to send fluid up to the spray nozzle. 16. Before fumes can be effectively scrubbed, the recirculation pump must be running. This is true even if fumes are note actively being pushed to or pulled through the scrubber (e.g. fumes from simple evaporation of liquid contained in storage tanks). The scrubber will not function properly if the recirculation pump is not on. 17. If the scrubber has a blower, adjust the damper such that the maximum vapor flow rate through the scrubber is not exceeded. Exceeding the maximum vapor flow rate may cause the scrubber column to flood. See table below: Maximum Allowable Vapor Flow Rate Through Scrubber at Recommended Liquid Flow Rates 14" Scrubber 24" Scrubber 30" Scrubber 280 cfm 828 cfm 1293 cfm Before setting the position of the damper, make sure that the vapor flow rate into the scrubber is as high as it ever would be. For example, if the scrubber is being used to treat vapor from multiple sources, identify all of the source(s) that would ever possibly be feeding the scrubber simultaneously. Make sure the blower is free to suck vapor from all of these source(s) prior to the damper being adjusted. To put it another way, assume you have three sources of vapor: A, B and C. Assume that when source A alone is open to the scrubber, it would provide 100 cfm of vapor flow. Assume source B alone would provide 25 cfm and source C would provide 10 cfm. If it s possible that sources A, B and C could all feed the scrubber simultaneously, open all three sources to the scrubber prior to setting the damper position. If it s possible that sources B and C could feed the scrubber simultaneously, but neither B nor C would ever feed the scrubber at the same time as source A, open source A to the scrubber (but leave sources B and C closed) prior to setting the damper position. Flow rates through the scrubber may be inferred using the blower curve and either a manometer mounted at the blower or a vacuum gauge and pressure gauge mounted at the blower inlet and outlet, respectively. These devices may be purchased through Salco if desired. Page 3 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

4 Operating Requirements Never allow the recirculation pump to run dry or run at a condition below its required net positive suction head. Do not dead-head the pump. If scrubbing HCl with water, the maximum recommended HCl concentration in the recirculating liquid is 4% HCl (by weight). Maximum liquid temperature is 130 F. NOTE: Liquid flow rates must be kept below certain maximums as well or column flooding may occur. These maximum rates cannot be obtained with Salco-supplied pumps provided vapor flow rates are kept at or under their prescribed maximums. If a non-salco supplied pump is used, contact Salco Engineering for maximum recommended flow rate. The minimum liquid pressure at the scrubber spray nozzle should be 5 psig. The below tables list the following information: o Orifice plate hole diameters for 14, 24 and 30 scrubbers (See the section regarding venting of pressurized vessels at the end of this document.) o Scrubber liquid recirculation rates for 14, 24 and 30 scrubbers The listed orifice plate hole size is the diameter that should be used to ensure that the maximum air flow rate through the scrubber is not exceeded when venting pressurized vapor to the scrubber. Exceeding the maximum vapor flow rate could cause flooding in the scrubber column. NOTE: Depending on the emissions requirements of your particular scrubber system, a smaller orifice hole size than what s listed in the table below may be required. The vapor flow rate required to meet your emissions requirements may be less than what s required to prevent the scrubber from flooding. Minimum Square Edged Orifice Plate Hole Diameters (for HCl vapor or dry air at 77 F) Scrubber Inlet Pressure 14" Scrubber 24" Scrubber 30" Scrubber 35 psi 0.90 in 1.60 in 2.00 in 30 psi 0.95 in 1.65 in 2.05 in 20 psi 1.05 in 1.80 in 2.25 in 10 psi 1.20 in 2.05 in 2.60 in Minimum and Recommended Water Recirculation Rates Flow Rate Condition 14" Scrubber 24" Scrubber 30" Scrubber Minimum Flow Rate 8.5 gpm 25 gpm 42 gpm Recommended Flow Rate 10 gpm 32 gpm 54 gpm Page 4 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

5 Changing/Emptying Scrubber Water 1. The scrubber liquid must be kept clean in order to ensure the scrubber is working efficiently. 2. With either the pump off or while fluid is flowing to the spray nozzle, remove the cam cap from the pump assembly at the three-way valve. 3. Connect hose or piping to the cam adapter. 4. Turn the valve handle to divert flow to the cam adapter. 5. When the liquid tank is almost empty, shut the pump off. DO NOT run the pump dry! It s best to leave a few inches of fluid in the tank to ensure that available suction head does not drop below what the pump requires. 6. For scrubbers with chemical neutralization systems, salt concentration will continually build in the scrubber liquid. Therefore, the scrubber liquid must be changed out periodically to avoid the precipitation of salt crystals onto the scrubber internals. See the section regarding chemical neutralization systems below. Note on chemical neutralization systems Various neutralization options are available for the scrubber system depending on the type of vapor being scrubbed. Take hydrochloric acid vapors for example. You could opt for no neutralization and simply use plain water as the scrubbing liquid. The scrubber liquid tank would be filled with fresh water, and vapors would be scrubbed until acid concentration in the water built up to a certain maximum value (around 4% is common). At that point, the acidized scrubber water must be pumped out and replaced with fresh water. Many people will use this acidized waste water to top off a truck filled with raw acid. Since scrubber liquid volume is much less than the total truck volume, you typically don t end up diluting the raw acid in the truck too much. A chemical neutralization system can also be incorporated. The idea is to consume the scrubbed pollutant via chemical reaction rather than letting it build up in the scrubber liquid. By not allowing the pollutant to build up, scrubbing efficiency is kept high. Note that although the pollutant doesn t build up, other chemical(s) will build up (whatever is produced by reaction of the pollutant with the neutralizing chemical). In the case of hydrochloric acid scrubbing, these products of reaction are typically table salt (sodium chloride) and water. The neutralizing chemical can either be added in a batch fashion each time the scrubbing liquid is replaced or in a continuous fashion. In the case of hydrochloric acid vapor scrubbing, caustic is a common neutralization chemical. If added in a batch fashion, you d add caustic at ~10% concentration to the scrubber liquid tank each time you replaced the fluid. Vapor would be scrubbed until the caustic was entirely consumed. You d typically use ph strips to monitor the amount of caustic remaining. ph probes are not recommended for batch systems. The high starting concentration of the neutralization chemical tends to damage ph probes. A conductivity probe could be used for monitoring, but interpreting the reading requires a little practice. When adding in a continuous fashion, a small dosing pump is used to meter in the neutralization chemical as needed. The pump is automatically cycled on and off according to a ph probe reading. See note regarding ph probes at end of this document. Continuous dosing systems must be monitored closely to ensure that concentration of the products of reaction don t get too high. In the case of reacting hydrochloric acid with caustic, the scrubber liquid must be replaced once salt concentration gets to ~10%. If it s allowed to build up more than that, salt may begin depositing on wetted surfaced inside of the scrubber system (packing, tank, piping, etc). A conductivity meter or hydrometer can be used to monitor salt concentration. Unlike in batch systems, interpreting conductivity meter readings in continuous systems is straight-forward. Page 5 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

6 Be sure to consider waste liquid disposal implications before deciding whether or not to add a neutralization system. In the case of hydrochloric acid, sodium chloride solution may be easier to dispose of than weak acid. It all depends on what is best for your particular facility. Note on minimum temperature tolerances of electronics Certain electronics common to scrubber systems cannot tolerate extremely low temperatures. Should Salco supply a control panel, it will come with an appropriately-sized panel heater. Otherwise, it is up to the customer to ensure that electronics are kept sufficiently warm. Below are some examples: 1. Paddle wheel flow meters: 0 F (not a concern on heat traced & insulated systems) 2. Paddle wheel flow display boxes: 14 F ( 5 F during storage) 3. Rosemount model ph probes: 14 F (not a concern on heat traced & insulated systems) 4. Rosemount ph/conductivity display boxes: 32 F ( -4 F during storage) 5. ABB model ph probes: 41 F (not a concern on heat traced & insulated systems) 6. ABB model ph/conductivity display boxes: -4 F ( -40 F during storage) Note on use of ph probes You should be aware that ph probes are maintenance-intensive items. Salco supplies a calibration / maintenance kit with each scrubber system in which a ph probe is incorporated. It is the customer s responsibility to ensure that ph probes are maintenanced and recalibrated at necessary intervals. Notes on maintenance of these probes are included in the set up instructions that Salco provides with ph probes. Calibration solutions have finite shelf lives. It is the customer s responsibility to ensure that all calibrations are performed with solutions that have not outlived their shelf lives. Note on power requirements Below are the specific types of electricity that can be used to power common electrical devices: 1. Recirculation pumps for standard-sized scrubbers: low or medium VAC, single-phase 2. Conductivity and ph display boxes: low or medium VAC, single-phase 3. Heat trace circuits and neutralization chemical dosing pumps: medium VAC, single-phase 4. Blowers: medium or high VAC, three-phase 5. Paddle wheel flow meters & ph/conductivity probes require no external power source Note that low voltage refers to V. Medium voltage refers to V, and high voltage refers to V. Page 6 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

7 Note on spacing/civil requirements The scrubber system as a whole will take up a certain amount of real estate at the installation site. The specific size of this footprint varies from system to system. Before pouring any sort of pad, containment area, etc., it is the customer s responsibility to consult Salco regarding recommended size of said footprint. The scrubber itself, the recirculation pump and the blower (if present) must be installed onto a level concrete pad. Blower assemblies are designed to discharge vapor ~10 ft above the mounting level of the blower. It is the customer s responsibility to support this length of ducting as necessary using guy wires, etc. Note that the scrubbed vapor that flows out of the scrubber will be saturated with water. Should a blower assembly be incorporated, condensation will build up inside this assembly at the lowest point in the assembly (blower & damper). The damper is not water-tight, so built-up condensation will leak out of the damper. The rate at which this leakage occurs is highest just after start-up of the blower. Water-sensitive equipment (like electrical conduit) should not be installed at ground-level in close proximity to the blower or damper. Note on venting of pressurized vessels Often times when a vessel like a truck, railcar, etc., is unloaded using compressed air, some residual pressure remains in the vessel after all of its liquid contents are removed. It is often desirable to vent this excess pressure to the scrubber. This venting is commonly done through an orifice plate mounted at the scrubber vapor inlet. The orifice plate restricts the flow rate of the vapor down below the maximum flow rate that the scrubber is able to handle. In the case of unloading liquid into plastic storage tanks, it is often not best practice to vent this pressurized vapor directly into the storage tank as a means of routing it to the scrubber. Plastic storage tanks often have limited pressure tolerances. Additionally, the flow rate of unthrottled, pressurized vapor through the scrubber may exceed the scrubber s maximum rated vapor flow rate. This can compromise the scrubber s ability to remove pollutants. Upon customer request, Salco can provide the hardware necessary to incorporate an independent vent line that allows vessels to be vented directly to the scrubber (bypassing storage tanks). This independent line is fitted with an orifice plate that automatically throttles vapor feed flow to the scrubber such that scrubbing efficiency is not compromised. This independent vent line can also be incorporated into an automated venting system for pressurized vessels. This system automatically shuts off flow into the storage tank and opens flow into the independent scrubber vent line at the moment all of the liquid has been offloaded from the delivery vessel. Contact Salco for more information. Page 7 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014

8 Note on Pressure / Vacuum Relief Salco-supplied scrubbers are not designed to be used as pressure or vacuum relief devices. Customers who use scrubbers for either of these purposes do so at their own risk. In fact, should a system be incorporated that allows direct venting of fumes to the scrubber (bypassing storage tanks), a check valve would be installed at the scrubber inlet that would prevent the scrubber from providing any vacuum relief to the storage tanks whatsoever Salco recommends that all storage tanks plumbed to scrubbers be fitted with appropriate pressure and vacuum relief valves. Cracking pressures for these valves should correspond to the design specifications of the tanks themselves. Note that storage tanks in general are not rated to tolerate virtually any vacuum. Redundant relief devices, especially in regards to vacuum relief, are always a good idea. Maintenance and Inspection of the Scrubber System Check the scrubber pump operating conditions (vibration, noise) as well as electric current value and discharge pressure and flow rate. When the pump has logged many hours of run time, the front casing screws attaching the pump head to the motor bracket may loosen. Tighten screws periodically while taking care not to deform the plastic parts. Also, after pump has been idled for a long time, tighten screws before pump is used again. Inspect the shower nozzle spray tip for potential clogging and proper spray pattern. Ensure that the packing is clean and not brittle. Check all hoses and tubing for cracking or splitting. Check fittings for leaks and loose connections. Questions? If you have questions regarding this form or any information contained herein, please contact either Dave Hammond ( ) or Geoff Bolak ( ) at Salco Products. Page 8 of 8 Document #: Fume Scrubber Revision 3; 2/27/2014