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Fume Scrubber Manual

Site Design, Installation, Start-Up, Operations & Maintenance

Salco Products, Inc. (Revised: June 9th, 2016)


Table of Contents Document Overview

Design Considerations

Site Preparation/Installation Considerations

Operational Overview

Installation/Start-Up

Operations

Inspection/Maintenance


Document Overview This document is a comprehensive informational guide to Salco-manufactured fume scrubbers. It covers a variety of topics: everything from process design considerations to operating and maintaining the scrubber system. The following gives a brief overview of the individual sections contained in the document and their intended audience. Design Considerations (design engineers, site managers, general contractors, installation personnel) This section contains information helpful for designing/updating the process in which the scrubber will be used. Site Preparation/Installation Considerations (site managers, general contractors, installation personnel) This section contains information to assist in prepping the installation site. It also covers important installation-specific topics. Operational Overview (site managers, operations personnel) This section provides a general overview of how the scrubber system works. Installation/Start-Up (site managers, general contractors, installation personnel, operations personnel) This section provides step-by-step instructions for installing and starting up the scrubber system. Necessary field adjustments for certain equipment are also covered. Operations (site managers, operations personnel) This section explains how to operate the scrubber system. Inspection/Maintenance (site managers, operations personnel, maintenance personnel) This section lists routine inspection and maintenance requirements for the scrubber system.


Design Considerations Space 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, constructing any sort of containment area, etc., it is the customer’s responsibility to consult Salco regarding the required footprint for the scrubber system. Power Requirements Below are the specific types of electricity that can be used to power common scrubber components:

1. Recirculation pumps for standard-sized scrubbers: 110-120 or 220-240 VAC, single-phase 2. Conductivity and pH analyzer (display): 110-120 or 220-240 VAC, single-phase 3. Heat trace circuits and dosing pumps for neutralization chemicals: 220-240 VAC, single-phase 4. Blowers: 220-240 or 460-480 VAC, three-phase 5. Paddle wheel flow meters & pH/conductivity probes require no external power source

If a control panel was not purchased with the scrubber system, it is the customer’s responsibility to supply all necessary electronics and controls (motor starters, contactors, breakers, on/off switches, lights, alarms, etc.) required to operate scrubber system. Salco-supplied control panels are designed to operate and distribute power to all electrical components provided with the scrubber system. All necessary electronics and controls come pre-installed. The customer simply has to connect the panel to a suitable power source and run wires from the panel to the various scrubber system power users (recirculation pump, blower, heat trace power supply box, etc.). Note that if the system came with a Salco-supplied control panel, the following components will run off of 220-240 VAC power. They should be wired as such in the field.

Recirculation pump Blower (if present) Heat trace cable (if present) Chemical dosing pump (if present)

Salco-supplied control panels require 220-240 VAC, single-phase power for systems that do not include blowers. Salco-supplied control panels require 220-240 VAC, three-phase power for systems that include blowers. If the appropriate 220-240 VAC power source is not available, Salco will provide an appropriate transformer upon customer request.


Vacuum Breakers and Pressure Relief Devices Scrubbers do not substitute or replace vacuum breakers or pressure relief devices. Salco-supplied scrubbers are not designed to be used as pressure or vacuum relief devices. Vacuum breakers and pressure relief devices must be incorporated appropriately as if the scrubber were not present. Customers who use scrubbers for either pressure or vacuum relief do so at their own risk. 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. Salco can provide corrosion-resistant pressure and vacuum relief valves. Consult Salco for further information. Vacuum relief is especially important if an independent vent line is incorporated into the scrubber system (a line that allows direct venting of fumes to the scrubber (bypassing storage tanks)). In such systems, 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. See the Venting of Pressurized Vessels topic later in this section. Diameter of Vapor Piping in Forced-Air Systems For scrubbers that come with blowers or venturi devices (forced-air systems), consideration must be given to diameter of the vapor piping that gets plumbed from the scrubber fume inlet to the location(s) where fume capture is required. Standard Salco-supplied blowers are designed to provide a minimum of approximately 2.5 inches of available water column vacuum at the scrubber fume inlet. In other words, vacuum is about 2.5 inches at the maximum recommended vapor flow rate through the scrubber system (maximum recommended vapor flow rates for each scrubber size are listed in the Installation/Start-Up section). Available vacuum will increase somewhat at vapor flow rates lower than the recommended maximums. Why is this important? Blower systems offer limited available vacuum to work with. Diameter of vapor piping must be sized large enough to accommodate the desired vapor flow rate. If vapor piping is too narrow, the desired vapor flow rate may not be achieved. Blowers with custom-specified performance curves (static pressure versus flow rate) are available. Consult Salco for further information. Venturi devices generate much more vacuum than do blowers. Generated vacuum for venturi devices is defined in terms of inches of mercury rather than inches of water column. Proper pipe diameters should still be taken into consideration, however. Skinny piping may lead to excessive compressed air consumption when venturi devices are used. Because large-diameter piping can be very heavy, it is recommended that duct-grade (thin wall) material be used for large-diameter vapor piping. Schedule 40 is appropriate for small-diameter vapor piping. Blower assemblies are designed to discharge vapor at roughly the same height as the top of the scrubber body. Salco provides a stainless steel stand to support the vertical exhaust pipe. The stand is not rated to any particular seismic or wind loading, however.


Materials of Construction Here is a list of typical materials of construction for Salco scrubbers and their components:

Scrubber Body, Base, & Piping PVC Scrubber Internals Polypropylene Sight Glasses Acrylic Gaskets EPDM / Viton Tanks HDPE Pumps Mag-drive, seal-less,

glass reinforced Polypropylene Blower (Fan) Fiberglass Venturi Blower PVC Rotameter (float-type flow meter) Polysulfone & PVC Paddle Wheel (flow meter) PVDF (Kynar ©) Fasteners 18-8 Stainless Steel Pump Stand Stainless Steel

*Alternate materials available upon request or depending on commodity being scrubbed.* Consult Salco for options.

Spigot/socket style (glue-in) ends are used in lieu of threaded ends where possible in order to minimize leaks on PVC and CPVC piping & fittings. Threaded connections, when used, are typically sealed with E6800 brand sealant. Any chemicals fed into the scrubber system (scrubbing liquid, fumes being scrubbed, and neutralization chemicals) must be compatible with the materials of construction. Venting of Pressurized Vessels Often times when a vessel (e.g. truck, railcar, etc.) is unloaded using compressed air some residual pressure remains in the vessel after all of its liquid contents are removed. In most cases it is desirable to vent this excess pressure to the scrubber. This venting is commonly done through a flow restrictor device (orifice plate) installed in the piping that connects the pressurized vessel to the scrubber. To keep scrubbing efficiency high, the orifice plate restricts the flow rate of vapor entering the scrubber. Salco can provide corrosion-resistant orifice plates sized to specific applications. Contact Salco for further information. In the case of unloading liquid into plastic storage tanks, it is often not best practice to vent residual 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 tanks and into the scrubber may exceed the scrubber’s maximum recommended vapor flow rate. This can adversely affect scrubber performance.


Important Note! Orifice plates should not be installed onto the main vent line that connects storage tank(s) to the scrubber. Doing so may cause excessive pressure to build up in the tank(s) should pressurized vapor be vented through them to the scrubber. Orifice plates should only be installed onto independent vent lines that are dedicated to venting pressurized vessels. These independent vent lines are typically teed into the main vent line that connects storage tank(s) to the scrubber. In such cases, a check valve should be installed onto the main vent line upstream from the tee. This will isolate the tanks from the pressurized vapor exiting the vessel being vented. The cracking pressure for this check valve should be less than the cracking pressure for any pressure relief valve(s) on the tank(s). 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 flow to the scrubber such that scrubbing efficiency is not compromised. As an advanced option, this independent vent line can 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. Minimum Temperature Tolerances of Electronics Certain electronics common to scrubber systems cannot tolerate extremely low temperatures. If a Salco-supplied control panel was purchased with the scrubber system, 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 analyzers (displays): ≥ 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 analyzer (display): ≥ 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 analyzer (display): ≥ -4 °F (≥ -40 °F during storage)

Chemical Neutralization Systems Upon request, Salco can supply an on-demand chemical neutralization system for your scrubber system. The following information pertains to neutralizing scrubbed pollutants via chemical reaction. Various neutralization options are available for the scrubber system depending on the type of vapor being scrubbed. The idea is to consume the scrubbed pollutant via chemical reaction rather than letting it build up in the scrubbing 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). The neutralizing chemical can be added either in a batch fashion each time the scrubbing liquid is replaced or in an on-demand fashion. Salco-supplied chemical neutralization systems use a dosing pump to add the neutralization chemical in an on-demand fashion. When adding in an on-demand 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 the Using pH Probes topic later in this section. Continuous dosing systems must be monitored closely to ensure that concentration of the “products of reaction” don’t get too high.


Salt is a common byproduct of the neutralization reaction. A conductivity meter or hydrometer can be used to monitor salt concentration. See the “Scrubber Control Panel User’s Manual” for Salco control panels for more information on how to properly operate on-demand systems. If you need a copy, contact Salco to get one. 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. Example: Hydrochloric Acid Vapor Water Only System

You could opt for no neutralization and simply use plain water as the scrubbing liquid. The scrubbing 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%wt 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 concentrated acid. Since the volume of scrubbing liquid is much less than the total truck volume, you typically don’t end up diluting the concentrated acid in the truck too much. Continuous Dosing System

In the case of hydrochloric acid vapor scrubbing, caustic is a common neutralization chemical. The “products of reaction” are typically table salt (sodium chloride) and water. The Salco-supplied dosing pump is used in conjunction with both a pH probe and conductivity probe. The analyzer (display) that comes with the probes is programmed to control the dosing pump based on the pH reading. The conductivity probe is used to measure the salt content as it builds up in the scrubber. Salco recommends (in the case of hydrochloric acid with caustic dosing systems) replacing the scrubber water prior to the salt content reaching ~8%wt. Failure to do so will cause salt-crystal buildup to occur in the scrubber equipment (packing, pump, tank, piping, etc), reducing scrubber performance. Batch Dosing System

Caustic (or any other suitable neutralization chemical) can also be added in a batch fashion. For scrubbing HCl fumes with caustic, you’d add ~8%wt caustic solution to the scrubbing liquid tank each time you replaced the fluid. Vapor would be scrubbed until the caustic was entirely consumed. The most common method used to monitor the amount of caustic remaining is periodic testing with pH strips. However, Salco can provide a conductivity probe and analyzer (display) that can display a conductivity trend over time. Scrubbing liquid should be replaced when the measurement “bottoms out” (meaning the measured conductivity reaches a minimum value and begins increasing thereafter). Important Note! pH probes are not recommended for batch systems. The high starting concentration of the neutralization chemical tends to damage pH probes. Using pH Probes You should be aware that pH probes are maintenance-intensive items. Salco supplies a calibration/maintenance kit with each scrubber system that includes a pH probe. 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.


Freeze Protection Salco sells heat traced & insulated scrubber assemblies that include self-regulating heat trace cable, fastening tape, insulation blankets, jacketed pipe & pipe fitting insulation, etc. The blankets are constructed of Teflon-impregnated fabric filled with fiberglass insulation. They are good for any climate (even very cold weather locations) and are rugged in design. The pipe and pipe fitting insulation is fiberglass batting jacketed with a flexible UV-resistant polyethylene covering. Salco uses this particular insulation because installation is relatively simple and does not require personnel trained in the craft. Salco considers this insulation suitable for locations that experience moderate winters (e.g. Midwest USA). For colder climates, Salco recommends that supply and install of insulation for pipe & pipe fittings be outsourced to a professional third party. Third-party insulation systems are typically fiberglass or mineral wool insulation. Mineral wool is preferred because it is water resistant. Jacketing is typically banded aluminum sheet. Seams are sealed with silicone or some other suitable flexible sealant. If the customer chooses to purchase the Salco insulation system, insulation of the scrubber tank and the lower portion of the scrubber body may need to be performed at the Salco shop prior to shipment (even if the customer elects to install the remainder of the insulation and jacketing themselves). Insulating the tanks and scrubber bodies is a specialty operation and cannot be performed effectively by inexperienced personnel. Note that Salco factory-installed insulation is of a slightly different type than the fiberglass/polyethylene insulation described above. For tanks and scrubber bodies factory-insulated by Salco, the insulation system is melamine foam jacketed with flexible PVC sheet. Seams are sealed with PVC tape and/or silicone. Note also that melamine insulation systems should be installed when ambient temperatures are above 40 °F. The PVC tape used to seal the seams becomes difficult to work at lower temperatures. It is also best-practice to leak test the piping with water before insulation is installed. Leak testing is obviously impractical at temperatures below freezing. The melamine insulation systems need to be inspected and maintenanced at regular intervals. The PVC tape used to seal the seams has a tendency to come unraveled over time. Seams sealed with sealant should also be inspected and re-sealed as necessary. Fiberglass/polyethylene systems should be inspected periodically for tears/holes in the polyethylene covering.


Site Preparation/Installation Considerations Foundation The entire scrubber system should be installed upon a completely level and stable foundation. The column should be affixed to the foundation using at least every other bolt hole in the octagonal base. 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 the base and the foundation. These nuts should be adjusted such that the scrubber base 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. Some warping or creeping of the base may occur during shipping and should be expected. The scrubber itself, the recirculation pump and the blower (if present) must be installed onto a level concrete pad. Thread Sealants For PVC or CPVC threaded ends, Salco recommends using E6800 brand thread sealant. If Teflon tape is preferred, do not use an excessive number of wraps. Excessive wraps will increase the effective diameter of the male threads and may cause female fittings to split when tightened. Plumbing Vapor Lines Vapor lines that carry fumes to the scrubber should be plumbed free of any low spots. Low spots will flood with condensed vapor. The lowest spot in the vapor piping should be at the scrubber fume inlet itself. If low spots are unavoidable, drain valves should be installed so that built-up liquid may be periodically drained out. Blower Systems Duct work connected to the blower must be supported independently from the blower inlet & outlet connections. Using the blower connections as a means of support may cause deformation and permanent damage to the blower. Salco-supplied blower assemblies include pipe stands for support purposes. Condensate will accumulate over time inside of the fan housing and will need to be drained out periodically, especially in sub-freezing weather. Salco-supplied blower assemblies include a hose and valve for drainage purposes. The condensate may contain some trace pollutant content, so use caution when draining. Dumping drained condensate into the scrubbing liquid tank is a good method of disposal. Locating Control Panels For systems supplied with conductivity/pH probes, cords are used to connect the probes to their analyzer (display). Standard length of these cords is 20 feet. If the scrubber came with a control panel, the analyzer will be mounted onto the door of the panel. The control panel must not be positioned too far away from the probes, or the cords will not be long enough. Longer cords or cable extension kits are available upon request. Contact Salco for further information. Exposure of Parts to Sunlight UV light will degrade PVC parts. The standard PVC-constructed scrubber columns are painted with a UV-resistant coating. However, the standard PVC liquid recirculation piping is not delivered with any sort of protective coating. For outdoor installations, it is recommended that the piping be painted by the customer with an appropriate UV-resistant coating after installation. The pipe should be cleaned of dirt, dust, etc, before painting. Manufacturer ink markings should


either be removed via sanding with fine-grit sand paper or coated with primer. If markings are sanded, be sure to clean off the residual dust before painting. Note that not all paints are suitable for PVC. The scrubber body has an epoxy primer undercoat and a polyurethane topcoat. Be sure that whatever paint/primer you use is compatible with plastic. Painting is not required for insulated systems.

Operational Overview The following is a brief overview of how a typical scrubber system works: Polluted vapor flows into the scrubber through a nozzle on the lower portion of the column. The vapor flows up through a “packed bed” inside of the column. Scrubbing liquid is pumped to the top portion of the scrubber, through an internal shower nozzle, and is sprayed onto the top of the “packed bed”. The packed bed consists of randomly-dumped pieces of “packing” that provide a large amount of surface area for the polluted vapor to contact the scrubbing liquid. The pollutant is transferred from the vapor to the scrubbing liquid inside of the packed bed. The resulting “scrubbed” vapor then exits out the top of the scrubber. The scrubbing liquid (with the pollutant now dissolved into it) drains down to the bottom of the column where it flows to a holding tank. From the tank, the liquid flows to a pump that pushes the liquid back up to the shower nozzle. The scrubbing liquid is continually recirculated in this fashion until the pollutant concentration in the scrubbing liquid reaches a certain maximum (beyond which scrubbing efficiency is compromised). At that point, the “dirty” scrubbing liquid must be pumped out of the scrubber system. The system must then be refilled with “clean” scrubbing liquid. Some scrubbers come equipped with chemical neutralization systems. When these systems are incorporated, the pollutant is not allowed to build up in the scrubbing liquid. Rather, a neutralizing chemical is pumped into the scrubber system to consume the pollutant. With these systems, the scrubbing liquid is replaced when a given “product of reaction” reaches a certain maximum concentration. A “product of reaction” is a substance formed when the neutralization chemical consumes (reacts with) the pollutant. The product of reaction of importance is usually a salt. If concentration of this salt is allowed to get too high, solid salt crystals will begin forming on the wetted surfaces inside of the scrubber system. This can severely affect the performance of the scrubber. Therefore it is very important to maintain the operation of the scrubber and replace the scrubbing liquid on a regular basis.


Installation/Start-Up Important Note! Scrubber systems should be installed under warmer weather conditions whenever possible. Liquid testing of all scrubber piping upon complete install of scrubber components should be done prior to installation of any insulation. This will ensure that any leaks in the system are caught and fixed prior to insulating the system. Customers may install insulation without leak testing, but do so at their own risk. 1. Carefully uncrate the scrubber. 2. Fasten scrubber base to a suitable foundation taking all precautions described in the Site Preparation/Installation

Considerations section above. 3. If present, remove the protective tape from the scrubber fume inlet flange. Connect the fume inlet flange to the

incoming vapor piping. 4. If present, remove the protective tape from the exhaust flange and bolt the exhaust stack onto the scrubber lid. 5. Blower (Fan) Install

If the scrubber came with a blower, the exhaust stack that normally bolts directly to the scrubber lid will not be included. The blower piping takes the place of the stack. Plumb the blower according to the CAD prints. Blowers should not be secured to foundations until they have been plumbed to the scrubber lid. NOTE: Standard blower assemblies are equipped with lengths of straight pipe on both the inlet and outlet-sides of the blower. The purpose of this straight pipe is to facilitate accurate manometer/vacuum/pressure gauge readings (which can be used with a blower performance curve to determine approximate vapor flow rate). If such readings are not of importance, the length of straight pipe on the inlet-side may be shortened to reduce the blower assembly’s footprint. Contact Salco for further information.

6. Venturi Blower Install If the scrubber came with a venturi device, it should be plumbed into the vapor line that connects the scrubber to the location where fumes are to be captured. The venturi device should be installed as close as possible to the fume source. After the device is installed, plumb a compressed air source to it. Most applications require compressed air at 60 – 80 psig. NOTE: Because they are capable of generating strong vacuum, Salco does not recommend using venturi devices on “closed” systems that are not equipped with adequately-sized vacuum relief devices. Using a Salco-manufactured loading cone to fill a truck is an example of a system that becomes “closed” once the cone is inserted. Upon inserting and securing the cone into the truck man way and bolting the liquid fill and vapor exhaust lines to the cone, the fumes exiting the truck have no way of escaping to the ambient surroundings (unless the man way is slightly out of round and the cone doesn’t fully seal the opening). A venturi device could possibly generate enough vacuum to implode the truck if compressed air was continually allowed to flow into the device after the cone was inserted. If the vapor discharge out of a venturi device is routed to a vent pipe connecting storage tank(s) to the scrubber, it is recommended that a check valve be installed on the vent pipe upstream of where the venturi discharge is teed into the pipe. This will isolate the tanks from the pressurized vapor coming out of the venturi device. The cracking pressure for this check valve should be lower than the cracking pressure for any pressure relief valve(s) installed onto the tank(s). Additionally, avoid filling storage tanks at the same time a venturi device is being used.


7. 14” 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.

8. 24” and 30” scrubbers come with a stand-alone tank. (A supplementary stand-alone tank is an optional component for 14” systems as well.) 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 tank for debris (plastic shavings, etc.) prior to plumbing it. Rinse out all debris with water. Debris can lodge in the recirculation pump and/or the shower nozzle inside of the scrubber column.

9. Chemical Dosing System If the scrubber came with a chemical neutralization system, install it according to the CAD prints. Choose a suitable location to mount the dosing pump. See the Using pH Probes topic in the Design Considerations section above.

10. Manometer(s)

If the scrubber came with manometer(s), install them according to the following instructions:

NOTE: The purpose of the scrubber body manometer is to measure the pressure differential across the packed bed inside of the scrubber. The purpose of the blower manometer is to measure pressure differential across the blower, from which a vapor flow rate may be estimated.

a. If the manometer is to be used on the scrubber body:

i. Locate the two ½” plugs on either side of the packed bed (one above and one beneath). Remove these plugs. ii. Apply thread sealant to the threaded portions of the barbed elbows supplied with the manometer assembly.

See the Thread Sealants topic in the Site Preparation/Installation Considerations section above. iii. Screw the elbows into the two holes in the scrubber body where the plugs were located. Position the upper

elbow with the barb pointing down. Position the lower elbow with the barb pointing up. iv. Determine the location on the scrubber body at which you’d like to mount the manometer. Hold the

manometer body at that location and, using a pen or pencil, mark the manometer body holes onto the scrubber body.

v. Drill and tap holes in the scrubber body at two locations: the marked position of the lower hole and the marked position of either of the two upper holes. Tapped thread size should be 8-32 UNC. Hole depth should be 5/16”. Be sure not to exceed 5/16” depth for 14” scrubbers.

vi. Use the two titanium screws supplied with the manometer assembly to affix the manometer body onto the scrubber body.


b. If the manometer is to be used on the blower assembly: i. Locate the two ½” plugs on either side of the blower. Remove these plugs.

ii. Locate the two vertical sections of ducting (the one that routes the vapor flow down from the top of the scrubber to ground-level, and the other that routes vapor flow from the blower discharge up to the exhaust tee). The PVC blocks supplied with the manometer assembly should be used to mount the manometer body onto either of these vertical sections of ducting. Only two of the four blocks should be used. Blocks for 14” scrubber blower assemblies will have greater curvature than the blocks for the 24” & 30” assemblies. Identify the two blocks you need based on what size scrubber blower assembly you have.

iii. Using the two titanium screws included with the manometer assembly, fasten the manometer body to the two PVC blocks. Fasten one block to the lower hole on the manometer body and fasten the other block to either of the two upper holes.

iv. Determine the location on either section of vertical ducting at which you’d like to mount the manometer. Hold the manometer body (with the PVC blocks attached) at that location. Press the blocks up against the ducting. Using a pen or pencil, draw lines on the ducting marking both the upper and lower surfaces of each block.

v. Remove the blocks from the manometer body. Using the drawn lines as a guide, use PVC primer & glue to affix the blocks to the ducting. Give the glue 60 minutes to dry. Re-fasten the manometer body to the blocks.

vi. Apply thread sealant to the threaded portions of the barbed elbows supplied with the manometer assembly. See the Thread Sealants topic in the Site Preparation/Installation Considerations section above.

vii. Screw the elbows into the two holes in the blower assembly where the plugs were located. Position the elbows such that they point toward the manometer body.

c. Follow the instructions included with the manometer (model 1221) for filling the manometer with gauge fluid. NOTE: The increments on the manometer body scale are spaced assuming that the red gauge fluid supplied with the manometer assembly is used. Using a different fluid will likely cause the manometer to read incorrectly. Also, the red gauge fluid is petroleum-based which prevents it from freezing. If you need to re-fill the manometer with fluid, use only the Dwyer-brand red gauge fluid (the same type as what came with the manometer assembly). Salco can supply replacement fluid. d. Cut two sections of hose to the appropriate lengths required to connect the elbows to the manometer body. One

elbow should connect to one port on the manometer body, and the other elbow should connect to the other port. It doesn’t matter which elbow connects to which port.

e. Use the pipe straps and cable ties provided with the manometer assembly to support the hose as necessary. Make sure the hose is secured enough to prevent kinks and/or flattened sections in the hose.

f. Slip a hose clamp onto both ends of both lengths of hose. g. Push both ends of both hoses onto the hose barbs and clamp the hoses down onto the barbs. Use silicone grease if

necessary to help the hoses slide onto the barbs. h. Follow the instructions included with the manometer (model 1221) for properly reading the manometer.


11. Control Panel(s) If the scrubber came with a control panel, mount it in an appropriate location. *Note: For standard systems the cords that connect the conductivity and pH probes to the pH/conductivity analyzer (display) are 20 feet long each. The analyzer comes mounted to the control panel door unless specified otherwise by the customer. Therefore if the control panel is mounted too far away from the pH/conductivity probes the cords won’t be long enough to reach the analyzer. *Contact Salco to order a cable extension kit if needed*

12. If the scrubber did not come with a control panel, install the panel-mount devices (pH/conductivity analyzer (display), paddle wheel flow meter display box, etc.) onto an appropriate enclosure.

13. Install all of the other electronics that came with the scrubber (conductivity probe, pH probe, paddle wheel flow meter, cords, etc.). See the Minimum Temperature Tolerances of Electronics topic in the Design Considerations section above. 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.) If using a Rosemount conductivity probe, the axis of the hole in the probe head should be perpendicular to the pipe run. In other words, flow through the pipe should impact the side of the doughnut. Flow should not pass directly through the hole in the doughnut.

14. If the scrubber came with a control panel, open the panel door and make sure all internal wire connections are tight. It is very common for connections to loosen in shipment. Problems with the scrubber electrical controls can usually be traced back to loose wires in the panel. Also make sure all conduit connections are tight. NOTE: Salco control panels come shipped with a “Scrubber Control Panel Users Manual”, which is a separate document than this one. Before powering up any device, be sure to read this manual thoroughly. If you need a copy, contact Salco to get one.

15. Run power as necessary to the motor(s) and electronics(s). Refer to the manufacturers’ installation procedures. If the scrubber came with a control panel, the panel should be wired to an on-site power source. 240VAC, 3-phase power should be fed to the control panel for systems that came with a blower. If the scrubber did not come with a blower, 240VAC, single-phase power should be fed to the panel. If your site does not have the correct power source, Salco can (or may have) provide(d) a transformer. Contact Salco for details. Power should be routed from the control panel to the individual power users (scrubber recirculation pump, blower, heat trace cable, etc.). The control panel contains all necessary motor starters, contactors, etc, required to power the equipment. See the Power Requirements topic in the Design Considerations section above for further information.

16. If necessary, heat trace & insulate the scrubber system to prevent freezing (recirculation piping, holding tank, and flooded portion of column). Use insulation blankets on odd-shaped components like valves, pumps, rotameters, etc. See the Freeze Protection topic in the Design Considerations section above.

17. Set the thermostat(s) controlling power to the heat trace cable to ~50 °F. 18. If the scrubber came with a blower, bump test it to make sure it’s rotating in the correct direction. Re-wire as

necessary.


19. Fill the scrubbing liquid holding tank with scrubbing liquid. If the scrubber came with a chemical neutralization system, fill the scrubbing liquid tank only half-way to start. This will leave room for the neutralization chemical to be added. Experience will dictate proper fill level thereafter. If ambient temperature is below freezing, do not add any liquid into the scrubber system until the heat trace system is fully functional and insulation has been installed. Note: Salco does not recommend install of systems in below freezing weather conditions, as doing so prevents proper leak testing prior to insulating.

20. Be sure that the three-way valve on the discharge-side of the scrubber recirculation pump is positioned such that fluid is pumped up to the shower nozzle.

21. Open all valves necessary to allow scrubbing liquid to recirculate (valve between scrubber and tank, valves between tank and pump, two-way valve between pump and shower nozzle).

22. First, bump test the scrubber pump to make sure it’s rotating in the correct direction. Re-wire as necessary. Then continue by running the pump to recirculate liquid, check the system for leaks. Do not run the scrubber pump unless fluid is free to flow to it. Do not run the pump dry!

23. Turn on all other electrical components to ensure everything works properly. 24. 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. Also, if the neutralization chemical is to be exposed to freezing temperatures, make sure the chemical is at a concentration that has a sufficiently low freezing point. If the freezing point of the chemical is above the lowest anticipated ambient temperature, the chemical should be stored in a heated and insulated storage container. The dosing pump and tubing should also be heated and insulated or otherwise protected from freezing. Salco does not provide heat trace and insulation for the chemical dosing system.

25. If using a chemical neutralization system, use the Salco programming guide to program the appropriate settings into the conductivity/pH analyzer (display). If you don’t have a copy of the programming guide, contact Salco to get one. Note: The Salco conductivity/pH analyzer programming guide assumes that the scrubbed fumes are acidic and that the neutralization fluid is alkaline. If the situation is reversed, consult Salco for recommendations on how to properly program the pH analyzer.

26. If the scrubber came with a blower, turn the blower on and leave it running until the dampers are set properly. (See below.)


27. Blower (Fan) Startup If the scrubber has a blower, adjust the two dampers per the procedure outlined below: Each blower assembly comes with two dampers. The inlet-side damper is mounted onto a tee fitting that is plumbed into the blower inlet piping. The outlet-side damper is mounted directly onto the blower discharge. The inlet-side damper is there simply to guarantee that the blower never gets starved of air. If the blower is starved of air, the fan assembly may begin to wobble. This may wear out the bearings prematurely. The inlet-side damper should be opened just a bit more than fully-closed and fastened tightly in place. Under normal circumstances, there is no need to open this damper more than a crack. The more this damper is opened, the less suction you will have available at the location where you’re trying to capture fumes. Note that if there’s no chance that the vapor system will ever become closed, the inlet damper may be kept entirely closed to maximize available suction. See Item 6 earlier in this section. Adjust the discharge-side 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, cause excessive liquid carryover to the blower assembly, and/or cause insufficient removal of the pollutant from the vapor stream. See table below: Maximum Recommended Vapor Flow Rate Through Scrubber at Recommended Liquid Recirculation Flow Rate

To Prevent Flooding Conditions in Scrubber

(larger flow rates may be possible depending upon application – consult Salco for further info)

14” Scrubber 24” Scrubber 30” Scrubber ~280 cfm ~840 cfm ~1400 cfm

Before setting the position of the outlet-side damper, make sure that the vapor flow rate into the scrubber is as high as it ever would be. If the scrubber is being used to treat vapor from multiple sources, identify all of the source(s) that would ever possibly feed the scrubber simultaneously. Make sure the blower is free to suck vapor from all of these source(s) prior to the damper being adjusted. Before adjusting the damper, set these sources open to the worst case scenario (highest potential combined flow) that the blower would ever see. For example, 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. Vapor flow rate through the blower may be inferred using the manufacturer’s blower curve and a manometer tapped into the blower inlet & outlet piping. A vacuum gauge and pressure gauge mounted at the blower inlet and outlet, respectively, may be used in lieu of a monometer. These devices may be purchased through Salco if desired.


28. Venturi Blower Startup If the scrubber came with a Vaccon CDF venturi device, adjust air flow according to the following instructions: (If device is not a CDF model, consult Salco for proper adjustment.)

a. Make sure the location from where you’ll be sucking fumes is open to the atmosphere. See Item 6 earlier in this section. b. Make sure the jam nut is tightened. If loose, rotate it clockwise until tight. c. Open compressed air flow to the device. Note that venturi devices will achieve maximum vacuum levels at any pressure above 50 psig. d. Note the rate of air being sucked into the venturi device from the fume source. e. To adjust the air flow rate, loosen the jam nut by turning it counter-clockwise and rotate the exhaust body (clockwise to decrease flow rate and counter-clockwise to increase it). Also see “Operating Instructions: CDF Series Air Amplifier Pumps” on the Vaccon website (www.vaccon.com/pdfFiles/Inst/OperInstrCDF.pdf). f. After setting desired vacuum level, tighten the jam nut by rotating it clockwise. For CDF 1500 and 2000 models with additional set screws for locking the jam nut, tighten the set screws evenly in a circular pattern. g. Turn off compressed air flow until suction at the fume source is required.

29. Turn on the scrubber recirculation pump. 30. Pump Startup & Flow Meter Calibration

If the scrubber came with a rotameter instead of a paddle wheel flow meter, close the two-way valve between the pump and the shower nozzle, then slowly open it. Do this every time after re-start of the pump. The rotameter may not read correctly otherwise. If the scrubber came with a paddle wheel flow meter, refer to the GF Signet website for setup and calibration instructions. Note: the following are the standard recommended liquid recirculation flow rates:

14" Scrubber 24" Scrubber 30" Scrubber ~10.5 gpm ~32.0 gpm ~54.0 gpm

If the flow rate exceeds the above recommendation, close the two-way valve between the pump and the shower nozzle until the recommended flow rate is obtained. If the two-way valve is fully open and the flow rate is still lower than what is listed above, that’s OK. Simply operate the system with the two-way valve fully open. Do not exceed the flow rates recommended above. Doing so will cause the shower nozzle to distribute water unevenly onto the packed bed inside of the scrubber and may cause the scrubber to flood. There may be specific applications that require a higher or lower recirculation flow rate. If this is the case, Salco will notify the customer. NOTE: Before fumes can be effectively scrubbed, the recirculation pump must be running. This is true even if fumes are not 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 running.

31. If the scrubber came with a chemical neutralization system and a control panel, position the neutralization pump switch on the control panel to “AUTO”. See the “Scrubber Control Panel Users Manual” for further info. If you need a copy, contact Salco to get one.

http://www.vaccon.com/pdfFiles/Inst/OperInstrCDF.pdf


Operating the Scrubber System 1. The recirculation pump must be running or the scrubber will not function properly. 2. Never allow the recirculation pump to run dry. Avoid dead-heading the pump. 3. You must replace the scrubbing liquid at regular intervals. For scrubbers without chemical neutralization systems,

excessive pollutant concentrations in the scrubbing liquid will adversely affect scrubber performance. For scrubbers with chemical neutralization systems, excessive salt concentrations will cause deposits on wetted surfaces, leading to decreased scrubber performance. See the Replacing Scrubbing Liquid section later in this document.

4. If scrubbing hydrochloric acid fumes with water, the maximum recommended HCl concentration in the recirculating liquid is 4% HCl (by weight). Maximum liquid temperature is 130 °F. These maximums may vary depending on the specific application. Consult Salco for further information.

5. If scrubbing hydrochloric acid fumes with water in conjunction with a caustic neutralization system, the maximum recommended salt concentration is 8%.

6. The shower nozzle should be inspected frequently for clogging. It is not uncommon for debris (plastic shavings from holding tanks, bits of Teflon tape, etc.) to become lodged in the shower nozzle. Lodged debris will cause a decreased liquid flow rate and an uneven spray pattern, both of which will adversely affect scrubber performance.

7. The vapor exiting the scrubber will likely be saturated with scrubbing liquid, so condensation will pool at the bottom-most portion of the blower assembly (e.g. the blower fan housing). The fan housing should be drained out at regular intervals. Failure to do so may cause damage to the fan blades and/or accelerate the overall corrosion rate of the blower. In freezing weather, the housing should be drained out every time after the blower is used. Do not close the drain valve until all of the condensate has drained out. Small amounts of liquid build-up over time are to be expected, but excessive amounts of liquid may indicate excessive vapor flow rate through the scrubber, meaning the outlet-side damper should be further closed off. If the drained-out liquid is corrosive (e.g. it bubbles on the concrete foundation), this may be an indication that vapor flow rate is too high and scrubbing efficiency is being compromised. If the scrubbing fluid is water only (no neutralization chemical added), check that the pollutant concentration in the water is not too high. Dumping the drained condensate into the scrubbing liquid tank is a good method of disposal.

8. Running the blower is typically only required when you have an “open” system. “Open” meaning that the system is not entirely sealed from the ambient surroundings. A fume hood positioned over an open man way on top of a railcar is an example of an open system. Without suction from the blower, fumes could escape to the ambient surroundings rather than being routed to the scrubber.

9. Running the blower is not necessarily required when you have a “closed” system. A storage tank with vent piping connecting it to a scrubber is an example of a closed system. The fumes have no way of escaping to the ambient surroundings, so a blower will not assist in fume capture. In rare instances some tanks have been known to “breathe” out of the pressure safety vent instead of breathing to the scrubber. This only happens when pressure safety vents have an extremely low set pressure. Salco recommends using tanks where pressure vents can be set to a 1.50 psig minimum set pressure and 0.250 psig vacuum relief. In the case of hydrochloric acid storage tanks, lower set pressures may cause leakage.

10. If the scrubber came with a venturi device, you must turn on air flow to the device before it will suck any fumes. 11. Do not use venturi devices in closed systems (systems not vented to the atmosphere). Unlike blowers, venturi devices

are capable of generating high levels of vacuum. A venturi device could cause implosion of vacuum-sensitive or non-vented equipment (e.g. storage tanks, tanker trucks, etc).

12. Use caution when venting pressurized vapor sources to the scrubber (e.g. blowing down empty tanker trucks and railcars). A flow restrictor device (orifice plate) may be necessary to prevent overloading the scrubber. See the Venting of Pressurized Vessels topic in the Design Considerations section above.

Replacing Scrubbing Liquid


WARNING: Scrubbing liquid contains chemicals which are potentially corrosive/hazardous. Proper PPE should be worn when replacing the liquid. Follow your company’s guidelines for handling chemicals when replacing scrubbing liquid. 1. If the scrubber came with a pH and/or conductivity probe, use the readings on the pH/conductivity analyzer (display)

to determine when the scrubbing liquid needs to be replaced. Maximum values depend on the specific pollutant being scrubbed, the specific scrubbing liquid being used, and presence/absence of a chemical neutralization system. Consult Salco for recommendations.

2. When it’s time to replace the liquid, shut the recirculation pump off. 3. Remove the cam cap near the three-way valve on the scrubber pump outlet piping. 4. Connect a hose to the male cam fitting. Position the other end of the hose into the vessel/receptacle that you want to

pump the old scrubbing liquid into. 5. Position the three-way valve such that flow is directed to the cam fitting. 6. Turn the recirculation pump back on. Monitor the liquid level inside of the scrubbing liquid holding tank. 7. When the liquid tank is almost empty, shut the pump off. It’s best to leave a few inches of fluid in the tank to ensure

pump cavitation (running dry or causing significant air flow through the pump) does not occur. 8. On 24” and 30” scrubbers:

A. Allow any liquid remaining in the hose to flow back into the scrubber system. B. Position the three-way valve such that flow is directed to the shower nozzle. C. Disconnect the hose from the male cam fitting and reinstall the cam cap.

9. 14” scrubbers have a check valve on the discharge-side of the pump that prevents liquid from flowing back from the hose into the scrubber system, so it is best to leave the hose connected to the scrubber system at all times: A. Drain as much of the residual liquid in the hose as possible into the vessel that was pumped into. B. Remove the hose from the vessel and cap or plug the vessel-end of the hose. C. Position the three-way valve such that flow is directed to the shower nozzle.

NOTE: Always dispose of old scrubbing liquid properly. Know what chemical(s) are in the scrubbing liquid. Different chemicals have different disposal criteria.


Inspection/Maintenance Note: Scrubber maintenance should always be performed by properly trained personnel. Use proper safety equipment and follow your company’s guidelines for handling chemicals when performing any work on the scrubber system. Daily Items: 1. Check recirculation flow rate. Lower-than-normal flow rate may indicate a plug at the shower nozzle.

If the scrubber system has a rotameter, the float may simply be off kilter due to debris or air bubbles. Refer to the Pump Startup & Flow Meter Calibration topic in the Installation/Start Up section above.

2. Check shower nozzle for uniform spray pattern. 3. Check recirculation pump for excessive vibration/noise. 4. If present, check the blower for excessive vibration/noise. 5. Drain any built-up condensate out of the blower fan case. 6. In freezing weather, drain out built-up condensate every time after using the blower. Don’t close the drain valve until

the drain line is completely empty. 7. Check scrubber system to see if the scrubbing liquid needs to be replaced:

A. Water Only Systems: check for maximum pollutant content (e.g. 4%wt HCl) B. Chemical Dosing Systems: check for maximum salt content (e.g. 8%wt NaCl) C. Batch Dosing Systems: check pH or trend line on analyzer (e.g. bottoming out of trendline)

Weekly Items:

1. Access shower nozzle sight glass with a ladder or man lift. Use flashlight to inspect shower nozzle for debris. 2. Check the entire system for leaks & drips. 3. If the scrubber system came with a Salco-supplied control panel, check the function of the e-stop system.

Monthly Items: 1. Check screws on recirculation pump case for tightness. 2. Hand check nuts on flanged connections, tighten if necessary. 3. If present, recalibrate pH probe & replace electrolytic gel as necessary. (Refer to the Salco programming guide for

Rosemount pH and conductivity probes.) Contact Salco for a copy if you need one and for ordering replacement calibration parts.


Yearly Items: 1. Check packing in scrubber column. Make sure it is clean & free of debris. Squeeze a couple pieces of packing

between your fingers. Make sure the packing is not brittle. Remove the top-side sight glass to access the packing. Replace the gasket when reattaching the sight glass. If sight glass becomes foggy, contact Salco to purchase a replacement.

2. Check the integrity of any hoses in the scrubber system. (Check for cracks, splits, discoloration.) Salco recommends replacing any hoses exposed to sunlight on a yearly basis.

3. Check electrical connections for corrosion/wear and tighten as necessary. 4. Check heat trace thermostat bulbs & capillary tubing for corrosion/wear. 5. Check the painted surfaces on the scrubber system. Touch up as necessary. 6. If present, inspect seams on insulation jacketing and re-tape, re-caulk as necessary. Check fiberglass/polyethylene

insulation components for tears/holes in the polyethylene jacketing. 7. If present, test the function of the high-level alarm on the scrubber body. 8. If the scrubber system came with a Salco-supplied control panel, check all panel-mounted lights to make sure none

are burned out.

Waste Fume Scrubber - Salco Products Inc.€¦ · This venting is commonly done through a flow...

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