So as to guarantee destruction of the VOCs, the temperature of the waste air stream should be raised to a comparatively high temperature, typically within the range of 1,200 to 1,800 degrees F or even higher.
Generally, some kind of fuel is needed (no less than partly) to bring the temperature of the waste stream as much as the temperature that provides settle forable oxidation (burning) of the contaminants. This fuel is often pure gas. At $0.60 to $0.80 per therm, minimizing the quantity of natural gas used can save plenty of money. So how do we decrease the fuel usage?
Thermal Oxidizer Types
A thermal oxidizer with no heat recovery is called an afterburner. Within this class, there are also thermal oxidizers that recover heat in some form. These are recuperative thermal oxidizers and regenerative thermal oxidizers (RTO). These provide apparent benefits over a straight afterburner, as heat is recovered from the relatively scorching exhaust gases.
If you could install a new oxidizer, consider utilizing a regenerative thermal oxidizer. This oxidizer has two circulate paths each with ceramic media in a bed. Stream is alternated via every bed in order that one is transferring heat to the cool incoming untreated air while the other "cool" bed is getting used to recover heat from the new handled exhaust. The movement is then switched back and forth between the two beds.
One other option is to put in a recuperative thermal oxidizer. This is generally not fairly as environment friendly as the RTO described above. A recuperative thermal oxidizer makes use of the recent exhaust to pre-treat the cool incoming air in a warmth exchanger. The recovered heat may be used elsewhere in the facility wherever it's needed. An example of this could be a waste heat boiler to provide steam.
One other type of oxidizer is called a catalytic oxidizer. This additionally entails using heat to oxidize contaminants, however it also incorporates a catalyst material to lower the temperature at which correct oxidation of the contaminant happens – typically within the 500 to 650 degrees F range. The benefits of a decrease temperature embrace much less supplemental fuel use. Warmth recovery may also be applied to this technology. Of course, the catalyst materials adds expense and maintenance.
Regardless of the option you choose, if your waste stream consists of a giant quantity with a relatively low concentration of VOC, consider adding a concentrator to your oxidizer system. This is exactly what it sounds like. The concentrator has media that adsorbs the contaminants from the waste stream prior to the oxidizer. The media is then "regenerated" with a decrease-volume higher-temperature air stream that is then oxidized more economically.
Select the Correct System for Your Software
In addition to selecting an oxidizer that's appropriate along with your contaminant stream, just be sure you choose a system that gives the most warmth recovery possible. Consider this; when you have 20,000 cfm of exhaust air at 1,500 degrees F, and you'll recover warmth so that the exhaust temperature is dropped to 300 degrees F, the quantity of heat recovered is over 8 million BTU per hour. That's equivalent to over one hundred residential furnaces!