What Is a Regenerative Thermal Oxidizer and How Does It Work?

A high-pressure supply fan pushes or pulls process exhaust fumes into the Regenerative Thermal Oxidizer input manifold during operation; the exhaust is then routed via an energy recovery chamber before being delivered to a ceramic canister, where the polluted air absorbs heat.

The pollutant-laden air is directed to the combustion chamber after passing through the ceramic media, where it is kept at the required temperature for destruction. The heated air is passed via a second energy recovery canister after oxidation, where it is cooled before being routed to the exhaust manifold; the airflow is swapped throughout the operation, so one ceramic chamber heats the air while the other cools it.

The General Way a Regenerative Thermal Oxidizer Design Works Is as Follows:

  • Process emissions are drawn into the RTO by a system fan.
  • The process stream is directed to the poppet flow control valves for control.
  • Untreated process emissions are directed into the first chamber, which is filled with ceramic energy recovery media, using poppet valves.
  • The polluted substances in the combustion chamber are swiftly broken up by high temperatures and turbulence.
  • The cleansed stream passes through the second media bed, where it releases up to 97 percent of its heat value.
  • The poppet valves switch every few minutes, and the flow reverses. The incoming filthy process emissions are preheated by the collected heat from the outgoing purified stream.
  • The exhaust stack releases clean, cool air into the atmosphere.

What Are the Applications of a Regenerative Thermal Oxidizer?

regenerative thermal oxidizer design

Manufacturers will frequently choose an RTO to control pollutants in high-temperature process exhaust because RTOs are created and manufactured for numerous industries and can fit into practically all industrial processes. This is due to the high temperature (and related expense) required to remove VOCs by thermal oxidation alone, as well as the possible implications that such a piece of equipment could have on lower temperature applications.

While each chemical processing, coatings, and paint company is different and has different needs, many find that RTOs are the best option for them. Due to its 99 percent+ destruction efficiency, thermal efficiency, and ability to be tailored, a regenerative thermal oxidizer design is generally the most effective choice for chemical processing under rigorous constraints.

Effects Of Three Canister and Multi-Canister Systems on A Regenerative Thermal Oxidizer Design?

For vapor-tolerant and aqueous applications, three-can RTO systems are the best option. The high DRE (over 99%) assures that the odor and organic substances are practically eliminated. The regenerative thermal oxidizer design transforms the contaminants in the stream into carbon dioxide and water vapor while also recovering thermal energy that might be used to lower the equipment's operating costs. This is performed in a manner that is quite similar to that of a two-canister RTO. A high-pressure fan system transports the VOC-laden exhaust stream into the heat exchange bed. The stream heats the material as it travels through it, preparing it for the combustion chamber.

To finish the oxidization process, the combustion chamber warms the stream using burners to the ideal temperature for combustion. The clean stream is then directed to the heat recovery chamber, where it travels through a media bed that cools the air while simultaneously heating the media. The third stage, which improves the efficiency of the three-can regenerative thermal oxidizer, takes place in the final chamber, which retains any lingering VOCs in the "clean" stream by purging it with fresh air. A 2-can RTO lacks this final stage, which is why a 3-can RTO can achieve a slightly higher DRE.

As For Multi-Canister Systems, Smaller Regenerative Thermal Oxidizers perform similarly to a 5-canister Regenerative Thermal Oxidizer. The exhaust stream adsorbs the heat energy stored in the ceramic media mass as it passes through the first bed of ceramic media, which pre-heats the exhaust stream; the exhaust stream next passes through the burner reactor chamber, where heat energy from the burner is injected to bring the system temperature up to operational temperature.

The clean exhaust stream then travels through the second energy recovery canister after the temperature has been raised and maintained. As the exhaust stream passes through the canister, the cold ceramic media mass absorbs the exhaust stream's heat energy and stores it for the system's reverse flow. The flow through the system is rotated once the heat energy of the first two canisters has been depleted by the absorption of the incoming air stream, so the incoming dirty air stream is directed through the second set of energy recovery canisters, while the clean waste gas is directed through the third set of recovery canisters.

When the heat energy is absorbed by the air stream in the second energy recovery canister set and then by the ceramic media in the third energy recovery canister set, the cycle rotates again, with the third canister set becoming the passageway for the dirty exhaust stream entering the RTO and the fourth canister set ceramic media absorbing the heat energy as the clean air exits the siphon. The 4th cycle is now complete, and the process moves on to the 5th and final cycle before starting anew at cycle 1.

What Are the Disadvantages of a Regenerative Thermal Oxidizer Design?

  • Electricity costs are very high.
  • A larger real estate footprint
  • Weight specification can be up to three times that of a recuperative oxidizer.