Odor Control
Corrosion-Resistant Components for Odor Control Systems
Odor control systems operate in some of the most aggressively corrosive environments in industrial and municipal service. Hydrogen sulfide, ammonia, mercaptans, and other odorous compounds are corrosive by nature, and the scrubbing chemicals used to neutralize them, typically sodium hydroxide, sodium hypochlorite, or sulfuric acid, are equally aggressive. Every component in an odor control system, from the collection ductwork to the scrubber vessel to the exhaust stack, must resist continuous chemical exposure from both the foul air stream and the treatment chemicals.
Cortrol supplies corrosion-resistant fiberglass reinforced plastic (FRP) equipment and components for odor control systems, including scrubber vessels, ductwork, exhaust stacks, dampers, and the chemical feed systems that support them. Our products are sourced from manufacturers with decades of experience building FRP equipment for corrosive air handling and gas treatment applications.
Scrubber Vessels & Towers
The scrubber is the core of most odor control systems. Wet chemical scrubbers remove hydrogen sulfide, ammonia, and other target compounds by passing contaminated air through a packed bed while a scrubbing solution is circulated over the packing media. The scrubber vessel must withstand simultaneous exposure to corrosive gases, acidic or alkaline scrubbing solutions, and elevated moisture levels on a continuous basis.
Cortrol supplies FRP scrubber vessels and packed towers through Belco (a division of NOV Fiber Glass Systems), Ershigs (a division of NOV Fiber Glass Systems), and Frontier Plastic Fabricators. Belco is an ASME RTP-1 accredited manufacturer of custom FRP equipment including scrubbers and towers for industrial, municipal, and power applications. Ershigs is the leading North American supplier of field wound FRP scrubber shells for demanding corrosion service. Frontier provides contact-molded scrubbers, stacks, and columns through 10′ diameter with resin and fiberglass capabilities tailored to specific corrosion, temperature, and abrasion requirements.
Ductwork
Ductwork collects contaminated air from odor sources and conveys it to the scrubber system. In odor control applications, the duct interior is exposed to the same corrosive gases the scrubber is designed to remove, making material selection critical. Metal ductwork in hydrogen sulfide service corrodes rapidly, leading to air leaks, structural degradation, and loss of system performance.
Cortrol supplies FRP duct from Belco and Ershigs for corrosive air handling and odor control applications. FRP duct provides the chemical resistance needed for continuous hydrogen sulfide and chemical fume exposure while maintaining structural integrity and a smooth interior surface for efficient airflow.
Exhaust Stacks
After scrubbing, treated air is discharged through an exhaust stack. Even after treatment, the exhaust stream may contain residual moisture, chemical carryover, and trace corrosive compounds that attack metal stack materials over time.
Cortrol supplies FRP exhaust stacks through Belco, Ershigs, and Frontier. Belco’s stacks and tower package systems offer chemical resistance, lightweight construction for easy handling and installation, weather resistance, and a long-lasting gel-coat exterior with UV protection. Ershigs is a leading supplier of field wound FRP stacks for corrosive exhaust service.
Dampers
Dampers control airflow throughout the duct system, balancing air collection from multiple sources, isolating sections for maintenance, and preventing backflow when the system is not operating. In odor control service, metal dampers are vulnerable to the same corrosive gases that attack metal ductwork.
Cortrol supplies FRP dampers from Belco for odor control, scrubber, and ventilation systems. Available types include:
- Control and balancing dampers for regulating airflow and balancing system performance
- Isolation dampers for shutoff or low-leakage performance during maintenance
- Backdraft dampers to prevent air from flowing back into the system when airflow stops
FRP dampers provide a corrosion-resistant alternative to metal dampers in environments where moisture, hydrogen sulfide, chemical vapors, and aggressive process atmospheres rapidly degrade traditional components.
Scrubber Chemical Feed Systems
Wet chemical scrubbers require a reliable supply of scrubbing solution, and the chemical feed system must be as corrosion resistant as the scrubber itself. Common scrubber chemicals include sodium hydroxide (caustic soda) for hydrogen sulfide removal, sodium hypochlorite (bleach) for oxidation-based treatment, and sulfuric acid for ammonia scrubbing. Each of these chemicals presents its own corrosion challenge for storage, piping, pumps, and valves.
Cortrol supplies the components that make up a complete scrubber chemical feed system:
Chemical Storage Tanks
FRP tanks and polyethylene tanks for scrubber chemical bulk storage, selected for compatibility with the specific scrubbing solution.
Chemical Feed Piping
FRP pipe and fittings for corrosion-resistant chemical delivery, and PTFE-lined steel pipe and fittings for applications requiring the mechanical strength of steel combined with broad chemical resistance.
Chemical Feed Pumps
Sealless magnetic drive pumps from ANSIMAG and Finish Thompson for leak-free chemical transfer, and air-operated double diaphragm pumps from RamParts for applications involving variable flow, high viscosity, or abrasive content.
Valves
Corrosion-resistant butterfly, ball, plug, and diaphragm valves with wetted materials matched to the scrubber chemical in service.
Supporting Components
Odor control systems include flanged connections, transitions between duct sections, and interfaces between FRP equipment and chemical piping. These connection points need the same level of corrosion resistance as the major equipment.
Expansion Joints
PTFE expansion joints absorb thermal movement, vibration, and misalignment in both ductwork and chemical piping, protecting FRP equipment connections and reducing stress at flanged interfaces.
Gaskets
PTFE gaskets provide corrosion-resistant sealing at flanged duct connections and chemical piping joints.
Custom Fabrication
Frontier Plastic Fabricators provides custom FRP components including transitions, reducers, and specialty fittings for odor control ductwork and scrubber systems.
Structural Access
FRP grating and handrail systems provide corrosion-resistant platforms and access around scrubber equipment, where hydrogen sulfide and chemical vapors create harsh conditions for steel structures.
Why Material Selection Matters in Odor Control
Odor control systems face a dual corrosion challenge. The foul air side of the system is exposed to hydrogen sulfide, which attacks metals aggressively, even at relatively low concentrations. The chemical side of the system is exposed to concentrated caustic, bleach, or acid used for scrubbing. Components that resist one side of this equation but not the other will still fail.
FRP construction addresses both sides. The resin system can be selected for resistance to both the gas-phase corrosion from hydrogen sulfide and the liquid-phase corrosion from scrubbing chemicals. When the same material discipline is applied to the ductwork, scrubber vessel, stack, dampers, and chemical feed system, the result is a system with consistent corrosion resistance and predictable service life.
Get System-Level Support
Whether you are building a new odor control system, replacing corroded metal components, or upgrading chemical feed infrastructure for an existing scrubber, Cortrol can help. Share your air stream composition, scrubber chemistry, and system layout, and our team will provide guidance on FRP equipment and components matched to your specific application.