4 Advice to Choose a Damper for RTO

25 Aug.,2025

 

Dampers for RTO's (Regenerative Thermal Oxidizer) - FlexCom

What is an RTO – Regenerative Thermal Oxidizer?

A regenerative thermal oxidizer (RTO) is an essential element in any facility that performs operations that produce industrial process exhaust. RTOs are responsible for cleansing the environment of air toxins, odors, volatile organic compounds (VOCs), and hazardous air pollutants (HAPs) that can be detrimental to one’s health, work environment, or production itself. RTOs are found in a wide variety of industries that perform procedures that require ventilation ranging from waste management facilities and chemical plants to food processing and vehicle manufacturing factories.

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The way RTOs work is by utilizing ceramic material to absorb heat from industrial exhaust gas and using it to preheat incoming gas. The RTO uses this stored heat to kill off any pollutants in the air discharged from process exhaust streams at a temperature ranging anywhere from 815 °C (1,500 F) to 980 °C (1,800 F).

The Purpose of Dampers for Your RTO

Industrial dampers (or valves) in a regenerative thermal oxidizer system are there to supply tight shut-off of process air to maintain destruction and removal efficiency (DRE) and appropriate heat exchanger operation thermal energy recovery (TER). Industrial dampers regulate airflow and allow for isolation of ducting and other equipment for maintenance purposes.

Choosing the right industrial damper for your RTO is imperative for maintaining optimal efficiency over a long period of time. Considerations such as maximum system pressure, air type, system design, temperature changes, and any stressors must be taken into account when selecting your custom industrial damper to maximize your RTO usage and maintain efficient VOC destruction. At Flexcom we’re determined to provide our customers with the appropriate custom industrial damper for your regenerative thermal oxidizers based on research, experience, and industry needs.

Butterfly Industrial Dampers for RTOs

The standard for RTOs for over 30 years, Butterfly Industrial Dampers inhabit less space than other valves and are extremely versatile owing to their design. These custom industrial dampers utilize a solid center-mounted rotating disc (or discs) that turns 90 degrees (activated by an actuator) for opening and closing to control the gas stream flow. In the closed position it blocks close to the entire stream flow (approximately 99.75% of airflow), and in open provides little in the way of flow restrictions. They are reliable in both modulating and on-off applications.

Butterfly industrial dampers require relatively low operating torque requirements while maintaining a fairly tight seal in closed positions. While the size and type of the custom industrial damper will determine torque and actuator requirements, the butterfly industrial damper is known for its versatility and effectiveness. The industrial butterfly dampers used in RTOs are the on-off type. Multi vane dampers are typically rectangular or square and can have several vanes or blades. These dampers can withstand temperatures up to degrees fahrenheit.

Poppet Industrial Dampers for RTOs

Initially created for use in fabric filter systems, poppet industrial dampers were later used in RTOs and have been ever since (for over 15 years now). Activated by an electric or pneumatic actuator the custom poppet industrial damper is a flat circular plate that is raised and lowered to press against or move away from a cylinder shaped seat. In the closed position gas seeking to flow past the cylinder is blocked, and in the open position there’s a one to two foot gap between the cylinder opening and flat plate.

Flexcom’s custom poppet industrial dampers are not for use in modulating applications. These are meant for on-off control only.

In RTO’s, poppet industrial dampers are particularly advanced sealing several gas paths while redirecting gas in various directions simultaneously. These dampers are activated by pneumatic or hydraulic cylinder actuators that provide high-cycle service and low-leakage isolation – poppet industrial dampers with zero-leak blades and seats are available as well. Poppet valves with three and four-way configurations are also common in some RTOs. A three-way poppet has one inlet and two outlets and cycles between two seats diverting flow through one while sealing the other. And four-way poppet dampers have two inlets and two outlets.

Hot Side Industrial Dampers (Bypass Dampers)

While most regenerative thermal oxidizers operate at temperatures ranging from º-º F, there are times when the heat may exceed that limit. For this reason installing a hot side industrial damper (or bypass damper) is an integral step for securing your RTO. A bypass damper will control the core temperature of your RTO and support it in maintaining a consistent temperature. Note that if temperatures in your RTO do not remain consistent, it will not convert gases and result in minimal heat recovery and conversion. This can also result in your RTO shutting down.

A hot side damper is vital under conditions where the level of volatile organic compound (VOC) concentration increases and pushes temperatures above their limit. When this occurs a variable energy-recovery (VER) system will activate the bypass damper opening it up to control the temperature. As the bypass damper opens, some of the hot gas from the burner chamber is diverted from the heat-exchange beds, thus regulating the temperature.

What Is A Regenerative Thermal Oxidizer (RTO)? - Kono Kogs

The Regenerative Thermal Oxidizer Process

The Simple RTO Process

An RTO uses six basic steps for each cycle to heat the incoming dirty air, burn off pollutants and cool the exhausted clean air.

  1. Polluted air is drawn into the RTO fan
  2. Polluted air is pushed through a valve system into one (of two) beds of ceramic media
  3. Air is pushed through heated ceramic media; heating the air while cooling the ceramic media
  4. Heated air is pushed into a combustion chamber where pollutants are burned off
  5. Clean, hot air is pushed into second (of two) beds of ceramic media; giving off heat to the ceramic media, cooling the air
  6. Clean, cooled air is pushed through open valve and exhausted into the atmosphere

LEARN MORE – How an RTO Works

Types of Regenerative Thermal Oxidizers

While RTOs can come in a few different configurations and layouts depending on the system’s requirements, the number of heat chambers used is the most common differentiator between types of RTOs. Also, there are variations in the types of valves used to reverse airflow direction. Some RTO technologies may not incorporate a traditional combustion chamber at all.

Essential differentiators between types of RTOs are:

  • Chamber Configurations
  • Heating Techniques
  • Air Flow Valves

LEARN MORE - Types of Regenerative Thermal Oxidizers

Applications of Regenerative Thermal Oxidizers

RTOs are used by manufacturers in a wide range of industries and applications. The Kono Kogs team has experience with practically every possible oxidizer application across many industries around the globe.

Industry Processes Using RTOs to Treat Emissions

  • Printing
  • Industrial Painting
  • Electronics Fabrication
  • Material Coating
  • Chemical Processing
  • Lamination
  • Can Production

LEARN MORE – RTO Industry Applications

How much does a regenerative thermal oxidizer (RTO) cost?

RTOs are sized and priced based on airflow volume that the system will treat. Total Cost of Ownership (TCO) is the initial capital investment in the equipment, plus installation costs, plus operating costs (fuel, electricity, and compressed air).

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  • RTOs have the lowest operating cost compared to other types of thermal oxidizers.
  • Lower cost units often have higher operating costs and lower reliability due to inferior components, and a design operating on its outer limits.
  • Fully refurbished RTO systems from Kono Kogs can save you 40% or more in capital costs compared to buying new – with comparable guarantees and warranties

LEARN MORE – RTO Costs

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‍Contact the KKI team for help selecting the most cost-effective RTO system for your application. We can turn quotes around within 24 hours for common applications. When special features are required, like hot gas bypass, puff capture, special metals, etc. a little more time will be needed to complete the quote.

Regenerative Thermal Oxidizer Design Factors

Certain RTO design factors can make a significant difference in both capital and operating costs:

  • Process air volume flowrate affects the size of the RTO unit, dampers and ductwork you’ll need.
  • Process air exhaust temperature determines the need for ductwork insulation, fan sizing, and affects expected operating costs.
  • Type & concentration of pollutants affects material of construction, heat exchanger efficiency, and greatly determines operating costs of electricity and fuel.
  • Complexity of RTO design affects how much RTO maintenance will be required. RTOs come in different designs, sizes and configurations.
  • Projected growth could make it smarter to install a higher-capacity system right away, rather than adding a second RTO in the future.

RTOs Compared to Other Pollution Abatement Systems

Regenerative thermal oxidizers have many advantages over other oxidizer designs, but application in a specific process must be evaluated to determine whether it is a good match for your emission control needs.

Regenerative Thermal Oxidizer vs Thermal Oxidizer

In thermal oxidizers, air flows only one direction through the system. RTOs however create airflow reversals using dampers and control logic, which makes them much more thermally efficient.

Compared to other thermal oxidizer systems, regenerative thermal oxidizers are more efficient and reliable, and have a longer service life. However RTOs have a more complex build and are heavier, which can affect shipping, installation and commissioning costs.

RTOs are the best option for most industrial processes, however when 99.99% destruction of VOCs is a requirement, a thermal recuperative oxidizer may be the better solution.

LEARN MORE – Regenerative Thermal Oxidizers vs. Thermal Oxidizers

Regenerative Thermal Oxidizer vs Recuperative Thermal Oxidizer

The main difference between regenerative and recuperative thermal oxidizers is how each one recovers heat while operating. Recuperative thermal oxidizers use metal as the heat exchange material, while regenerative thermal oxidizers use ceramic media.

Regenerative Thermal Oxidizer Components

In many cases, KKI can help businesses comply with environmental regulations and reduce operating costs by repairing, rebuilding, or upgrading their existing regenerative thermal oxidizer. We have an extensive inventory of RTO parts including ceramic media, fans, burners, and much more, plus an in-house fabrication shop.

When the cost of regenerative thermal oxidizer repair outweighs the benefit, KKI can facilitate RTO replacement. We offer fully refurbished systems with parts and performance warranties.

Available RTO components from Kono Kogs

  • Exhaust stacks
  • Combustion chambers
  • Media chambers
  • Media cold face support
  • Gas trains
  • Process ductwork/supports
  • Process T dampers
  • Hot bypass valves
  • Access platforms
  • PLC cabinets
  • Actuators
  • Insulation & cladding
  • Pneumatic controls

Kono Kogs RTO upgrades/services

  • Ceramic media change outs & upgrades
  • Fan balancing/rebuilds/relocation
  • Damper replacement
  • PLC programming & upgrades
  • Burner/gas train upgrades
  • Turnkey capture systems
  • Exhaust stack reconfiguration
  • Fan motor rebuilds
  • Preventive RTO maintenance programs
  • Remote monitoring hardware/software
  • Full turnkey installation

The components and services above are by no means comprehensive. KKI can handle any RTO rebuild or replacement project you are facing. We invite you to send us your trickiest projects; we look forward to the challenge!

Regenerative Thermal Oxidizer Manufacturers

The best-built RTOs make the best used RTOs. KKI selects only the best pre-owned regenerative thermal oxidizers and stands behind them with warranties that match new equipment Original Equipment Manufacturer (OEM) warranties. Check out our current RTO inventory from manufacturers including:

  • CECO ADWEST Technologies
  • Dürr MEGTEC Systems
  • CMM Group
  • REECO (Dürr)
  • TANN Corp.
  • Alstom

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