Tri-Mer - NOx Multi-Chem Wet Scrubber System
From Wet Scrubbers
Tri-NOx NOx scrubber system accommodates any combination of NO and NO2, including nitration-related NOx, which is typically high on the NO2 scale, and combustion-related NOx, which is higher in NO.
Tri-Mer’s NOx scrubber guarantees a clear stack and eliminates the visible plume generated by high NO2 loading. This yellow-brown gaseous emission is generated by processes using nitric acid in conjunction with metal refining, metal finishing or chemical nitration.
Tri-Mer’s NOx scrubber is applicable to hot and cold gas phase systems. It handles multiple gas stream residuals, including Cl2, HCl, SO2, other acids, other gases, caustics, and particulates. This wet chemical non-catalytic system cannot be blinded and there is no catalyst to poison.
The system is ideal wherever nitric acid is used to dissolve precious metals, and NOx is generated.
Scrubbing liquid is evenly distributed over the top of the packing by an arrangement of spray nozzles on one or more headers.
The system has no cfm or ppm limitations. Tri-Mer’s NOx scrubber achieves virtually any target stack output, including reducing loads of 100,000 ppm to below 5 ppm.
Systems are guaranteed to operate within pre-determined ppm limits for stack output without repeated adjustments. Tri-NOx is the technology of choice wherever NOx emissions are most restrictive.
All materials of construction and hardware are resistant to attack by the compounds being absorbed and the scrubbing solutions.
Vessels are polypropylene, PVC, FRP, or stainless steel.
Packing is a random-dumped, high-efficiency type, fabricated from polypropylene, with a nominal diameter commensurate with the tower diameter. Packing is Tri-Pack, manufactured by Tri-Mer Corporation.
The mist eliminator is integral to the scrubber and consists of several layers of polypropylene monofilament mesh pad material. The demister is six layers of Kimre Style 37/97 material.
The Tri-NOx Multi-Chem NOx Scrubber controls total NOx, NO2, and NO.
NOx Scrubber Design
The NOx scrubber system is engineered to treat a specific cfm range of gas, within a specific temperature range. Further, the system is engineered to reduce the level of contaminants from a specific inlet concentration to a specific outlet concentration. Equipment is designed for continuous operation in a specific seismic zone and environment, with a specific mph wind load. Once these 7 parameters are supplied by the customer, design can begin.
A portion of the scrubbing solution is purged from each recycle tank in order to prevent excessive accumulation of compounds, which could reduce efficiency of the scrubber or cause fouling.
Make-up of evaporation and other water losses is accomplished by continuous or controlled water additions. Fresh water is added to the last recycle tank to create a purge stream, which flows through the scrubber system countercurrent to the direction of air flow.
Equipment, materials, and workmanship conform to good engineering practices and to the latest edition of the codes or standards published by:
- American National Standards Institute (ANSI)
- National Electrical Code (NEC)
- Underwriters Laboratories (UL)
Packing is a random-dumped, high-efficiency type, fabricated from polypropylene, with a nominal diameter commensurate with the tower diameter. Packing is Tri-Packs, manufactured by Tri-Mer Corporation.
Oxidation towers are complete, including all internals, mist eliminators, liquid distributors, air inlet and outlet, access doors, couplings or flanges for connection of instruments or plumbing, lifting lugs, anchoring lugs, and other appurtenances shown on the drawings, or necessary for safe and efficient operation of the system.
The vessels are filament wound glass-reinforced plastic construction. The resin is a vinyl ester type.
Oxidizer suspension pads are provided at two locations in each tower to retain chemicals sprayed into the gas stream to oxidize nitric oxide. The pads consist of several layers of material, constructed from polypropylene or PVDF monofilament. The pads are six layers of Kimre Style 37/97 material.
The mist eliminator is integral to the scrubber and consists of several layers of mesh pad material constructed from polypropylene monofilament.
Oxidizing chemicals are evenly distributed over the top of the suspension pads by an arrangement of spray nozzles on one or more headers. The entire liquid distributor is PVC.
Recycle and Overflow Tanks
A tank is furnished for each reduction stage so that scrubbing solution may be re-circulated through each scrubber. The overflow tank receives liquid purged from the scrubbers and oxidation towers.
Each tank is a vertical, cylindrical vessel with flat bottom and domed top.
Tank capacity provides for a minimum of two-and-a-half times the recycle rate.
The tanks are of filament wound glass-reinforced plastic construction. The resin is vinyl ester type.
Horizontal end-suction centrifugal pumps deliver scrubbing solution from the recycle tank to the spray nozzles in the scrubber, and discharge effluent from the overflow tank.
Pumps, drivers, and auxiliaries are suitable for start-up and continuous operation in an outdoor, totally unprotected environment, and at any temperature within the design range.
Pumps are top-discharge, self-venting design with fully confined gaskets. Suction and discharge connections are 150# standard ANSI flanges.
Pumps are FRP or stainless steel ANSII design, or approved equal.
Chemical Metering Pumps
Chemical metering pumps are positive displacement diaphragm type. They deliver one of these chemical solutions:
- Sodium sulfide
- Sodium hydroxide
- Sodium chlorite
- Sulfuric acid
Chemical Storage Tanks
Chemical storage tanks have flat-bottom, cylindrical construction with dome or conical top. They are fabricated from filament wound glass-reinforced plastic. The resin is vinyl ester type.
Motors conform to the latest revision of NEMA standard publications MG1 and MG13.
Motors are standard foot-mounted type with rigid base design. They are NEMA design B (normal torque).
Motors are for continuous duty and have TEFC (totally enclosed, fan-cooled) enclosures.
Exhaust Gas Analyzer
An optional continuous emissions monitor is furnished to measure concentrations of nitric oxide (NO) and total NOx, and to calculate nitrogen dioxide (NO2).