Frequently Asked Questions
We love to share our knowledge of thermal oxidizers and regenerative thermal oxidizers to help business owners and future owners navigate the sometimes confusing world of oxidizers. Below are some of the questions Kono Kogs deals with on a daily basis. If you don’t see what you're looking for, don’t hesitate to contact us and we will be happy to answer any of your oxidizer questions.
- A puff capture feature can help eliminate visible emissions
- Remote access can ease troubleshooting and reduce the frequency of service visits
RTOs typically operate at 1500o – 1600o Fahrenheit depending upon the VOC characteristics. Thermocouples inside the chamber monitor temperature and adjust gas burner firing as needed. Adequate temperature is essential to ensure VOC destruction efficiency. In most cases a data log of chamber temperature is required for air quality compliance.
TOXs typically operate at 1400o – 1500o Fahrenheit depending upon the VOC characteristics. Thermocouples inside the chamber monitor temperature and adjust gas burner firing as needed. Adequate temperature is essential to ensure VOC destruction efficiency. In most cases a data log of chamber temperature is required for air quality compliance.
Yes. It is normally a simple conversion
In most cases, yes. But proper evaluation is recommended to establish that no potential catalyst poisons or masking agents are present in your airstream.
- VFDs are important for efficient operation, volume turn-down and idle operation
- Special materials of construction may be required
Catalyst utilized in a catalytic oxidizer allows chemical reactions to occur at lower temperatures (600-650F) than they occur in a thermal oxidizer (typical 1400-1450F) or an RTO (typical 1600F).
Regenerative thermal oxidizers have a heat recovery (efficiency) of 95% typically. This technology has the lowest operating cost of all thermal oxidizer systems – not to mention the longest service life and highest reliability. It’s even possible for an RTO to operate with no auxiliary fuel use whatsoever if process VOC concentration levels are >3-4% lower flammability limit (LFL).
Thermal Oxidizers (TOX) have a heat recovery (efficiency) of 70% typically, but some custom designs will use lower efficiency heat echangers if VOC concentrations are elevated. This technology has higher operating cost than most oxidizer systems.
Annually (and is usually determined by your operating permit)
RCOs offer greatest fuel economy by far, but recuperative units may be best for high VOC concentration airstreams (or an RTO can be considered).
It depends on numerous factors. See Selecting an Oxidizer for guidance or call us for guidance
- Ease of installation results in lower turnkey cost
- Maximum thermal efficiency
- Lowest pressure drop
- Ability to handle organic/inorganic particulates
- Rotary valve technology may be a better option
- A bake-out feature can address organic compound build-up
- Quality-built used regenerative thermal oxidizer (RTO) systems have a long life, can save 40% vs. new units, and have performance and parts warranties comparable to new systems.
Provide us your particulate description, or send us a sample. We can recommend a cleaning cycle and procedure, new more plug-resistant media, upstream filtering, and/or regular media change outs. A site visit will be needed to fully evaluate the issue.
Yes we can come out and help to determine what the problem is. Whether it be switching valves leaking; a leaking heat exchanger; poor air flow distribution; or poor catalyst performance. We can do a thorough evaluation and provide a turnkey solution in a short period of time and help to keep you in operation. If your system is a regenerative thermal oxidizer (RTO) see this blog post about stack test failures for more details on troubleshooting your RTO and test method.
We can come in and evaluate the controls and make recommendations for changes to alleviate this situation. Your oxidizer shouldn’t be dictating your production. Our service technicians are working throughout the USA on a regular basis. We may have someone near you right now. Check out our service page for more details or contact us.
Our experience is that regenerative thermal oxidizer (RTOs) systems less than 20 years old are good candidates for rebuild/repair/upgrade rather than for RTO replacement. Replacement costs including removal of existing, capital cost of a replacement system and shipping, ductwork, mechanical assembly, etc. add up quickly making it more cost effective to repair the system, upgrade the PLC, and/or add energy saving updates. Thermal recuperative oxidizer systems on the other hand usually are not cost effective to repair for long term use, but simple repairs may help limp these systems along until a replacement can be budgeted for. Catalytic recuperative oxidizers can be repaired, but the cost of catalyst replacement may justify replacement of the system if the catalyst has a history of contaminating quickly. Contact us and we can visit to make an evaluation. We want long term relationships with our customers so we provide our best evaluation of the total cost of ownership of each option so you can make an objective decision.
Yes we can help with either one of these scenarios. We have extensive fabrication capability and can provide some or all of the ductwork needed. Our crews can install the oxidizer and cutwork as turnkey or any portion of the project you would like to hand off to an experienced professional. Check out a few of our case studies for examples of our capabilities.
We can evaluate the existing oxidizer capacity and the requirements of the new process and determine the best approach to upgrade the oxidizer. This could include new heat exchanger media, a larger fan or possibly both. We would also evaluate things like the burner system and combustion chamber size to verify it can provide the required destruction levels. Some applications would be a good match for a VOC concentrator that can significantly concentrate (>10:1) airstreams currently exhausting to the oxidizer.
This is a common concern. Will the buyer be left with only promises, or will Kono Kogs provide robust support after the purchase and commissioning of the oxidizer? We have never failed to meet our warranty in either parts or oxidizer performance. We have references that will attest to this in every business size- from start-up bootstrapping companies, to growing small and mid-size companies, to Fortune 500 companies. Our experienced staff can handle any technical or maintenance issue, both on-site, and via KONOConnect to ensure a successful project, now and into the future with our long-life refurbished oxidizers.
Our warranty rivals that of new equipment OEMs and we can even extend the period, if desired. How do we do that? We offer only the best built systems from the best names in the industry. We also perform extensive sub-system and parts checkouts and replace faulty or questionable parts, many times with upgraded parts. Our goal is a flawless project- achieved with collaborative planning with our staff’s extensive oxidizer experience. We are honored that our customers are our best advocates. They affirm that we deliver what we promise- which has been true since day one of Kono Kogs.
This is a common concern. Will the buyer be left with only promises, or will Kono Kogs provide robust support after the purchase and commissioning of the oxidizer? We have never failed to meet our warranty in either parts or oxidizer performance. We have references that will attest to this in every business size- from start-up companies, to growing small, and mid-size companies, to Fortune 500 companies. Our experienced staff can handle any technical or maintenance issue, both on-site, and via remote monitoring to ensure a successful project, now and into the future with our long-life refurbished oxidizers.
Our warranty rivals that of new equipment OEMs and we can even extend the period, if desired. How do we do that? We offer only the best built systems from the best names in the industry. We also perform extensive sub-system and parts checkouts and replace faulty or questionable parts, many times with upgraded parts. Our goal is a flawless project- achieved with proper planning and with our staff’s extensive oxidizer experience. We are honored that our customers are our best advocates. They affirm that we deliver what we promise- which has been true since day one of Kono Kogs.
Yes, we can evaluate the heat exchanger whether it be metal (recuperative) or ceramic media (regenerative) and determine whether it can be upgraded to a more efficient type. Or maybe catalyst could be added in this case. In some cases it may be better to replace the current oxidizer with something more efficient. In that case we can look at our inventory and determine whether we have something that will provide better gas efficiency. If not, we can provide a custom system designed specifically for your needs.
Yes we have a team of experienced fabricators and insulators we can bring in to repair your oxidizer. Damaged metal may have to be replaced to ensure a secure surface is available to weld the insulation modules to.
We can come in and evaluate the current system by taking flows and readings at certain points of the system. Then we can determine whether the current system is optimized. If it isn’t we can recommend how to do that. If area capture hoods or enclosures need to be added we can recommend that as an option as well. We can also provide these things on a new system.
Chemical, pharmaceutical, OSB (oriented strand board) press, particle board dryer, MDF (medium density fiberboard) dryer, plywood, paint spray booths; and any application under 2% LFL is a good candidate
TOX with heat exchangers typically have a shorter life span than CATOX systems or RTO systems. This is due to the elevated operating temperatutres that te heat exchanger is exposed to. Especially deterimental to the system are repeated on/off cycling that imposes significant thermal stress on the heat exhanger. It is best to apply these systems in applications that run 24/7/365.
Particulate free or well filtered airstreams with no catalyst-masking chemicals
Regenerative and Recuperative
Extensive catalyst application experience allows our engineers to select the right catalyst type, and pair it with an optimized ceramic media mix for long life, and for low fuel and electric use.
The term “regenerative” in regenerative thermal oxidizer is drawn from the type of ceramic media heat exchanger used in these systems. It is unique in that it captures heat from the exhausting, clean airstream during one cycle and releases the heat to the incoming, dirty airstream in the next cycle. The heat is captured (and released) from beds of ceramic media. The RTO incorporates switching valves to cycle the direction of the airflow through the RTO heat exchanger beds to enable regenerative heat recovery.
Clean process airstreams with high air flow and low VOC content (<10% LFL) are ideal applications. Higher VOC concentrations can be tolerated, as well as organic/inorganic particulates with proper planning and design, and possibly filters. See our case studies for a sample of possible applications.
Fairly clean process airstreams with low to medium air flow, and medium to high VOC concentrations (>10% LFL). TOX systems can be custom designed to handle high VOC concentrations as compared to CATOX and RTO systems. Typical applications are petrochemical, and chemical airstreams. Special applications are best served by TOX, such as silicone containing airstreams, or processes where secondary heat recovery allows the TOX to operate as efficiently as RTO systems or CATOAX systems because of the heat returned to the process.
Catalytic Recuperative Oxidizers destroy pollutants discharged in the exhaust air of industrial processes. They achieve high VOC destruction efficiency by heating and maintaining a polluted airstream at temperature (typically 600 to 650F) for a set “dwell” time as it passes through catalyst material. The lower operating temperature of a catalytic oxidizer results in much lower fuel use than thermal recuperative oxidizers. VOC destruction efficiency can reach 99+%. Catalytic oxidizers can operate with an integral heat exchanger for fuel savings, or for a lower capital cost, without a heat exchanger. Learn more here.
RTOs typically have a 0.5 second to 1.0 second dwell time for most applications.
TOX typically have a 0.5 second to 1.0 second dwell time for most applications.
Up to 99% VOC destruction efficiency; and up to 97+% thermal efficiency.
Typically 1400 F minimum up to 1550 F depending upon the VOC characteristics.
An RCO is essentially an RTO with a catalyst layer added. (See What is an RTO?).
VOCs must combine with oxygen and heat to trigger the chemical reaction that breaks them down into CO2 and H2O. There are many successful thermal oxidizer designs that ensure sufficient turbulence, such as introducing the process air at an angle to induce spin or creating internal choke points. The better the mixing and heat distribution, the higher the VOC destruction.
Chemical, pharmaceutical, and wood products.
Fuel injection can provide significant fuel savings
Solvents with a high boiling point can build up on a forced draft fan wheel