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Thermal
Oxidation Systems
High-temperature thermal oxidation is a longstanding CSM
specialty. Our thermal oxidizers accomplish the same oxidation processes as
our catalytic oxidizers. However, thermal oxidation is initiated in an
oxidation chamber to combust pollutants at the elevated temperature of
about 2000 °F.
Regenerative Thermal Oxidizers
CSM regenerative thermal oxidizers (RTOs) destroy more than
99% of air toxics and VOCs. Our systems use high-temperature thermal
oxidation to destroy VOCs, oxidizing them to CO2 and
water vapor, then reusing released energy to reduce operating costs.
Process gas with VOC contaminants enters the CSM RTO through
an inlet. A flow control valve directs this gas into a hot direct contact
ceramic heat exchanger, which pre-heats the process stream. The process gas
is heated in the hot ceramic bed as it moves toward the combustion chamber.
The VOCs are oxidized in the combustion chamber, and
exhausting gas exchanges heat to the cooler ceramic bed, thereby reducing
the fuel requirement. The cold bed is heated and the gas is cooled so that
the outlet gas temperature is substantially reduced. The flow control valve
switches beds so that the heating and cooling ceramic beds are reversed. If
the process gas contains a high quantity of VOCs, the energy released from
their combustion allows self-sustained operation.
SLC-based electronics automatically control RTO operation from
start-up to shutdown to minimize operator interface.
Our RTO systems process 5,000 to 25,000 SCFM of VOC- or
CO-laden gas using the following key components:
- A process air blower/motor with an
automatic flow control system to push the VOC-laden gaseous stream
through the CSM RTO system, which can be designed for vertical flow.
- A custom, packaged burner system
with staged injection of the off-gas, natural gas as fuel and
combustion air, which achieves a very low NOx emission rate from the
system.
- An oxidation chamber capable of operating
at elevated temperatures ranging from 1400 to 1800 °F. It typically
operates at 1600 °F to treat the VOC-laden process exhaust system and
achieve the required destruction efficiency, including 99% of the
non-methane hydrocarbon compounds, which are converted to harmless CO2 and water
vapor.
The oxidation chamber is constructed of carbon steel lined
with rigid castable refractory (Kastolite or an equivalent) rated for
operation up to 2300 °F. An independent control panel automatically records
temperature rise due to VOC oxidation and controls fuel input to the burner
in order to maintain a set operating temperature. An Allen-Bradley SLC-500
series processor is used for system control, and a Panelview touch-screen
graphics panel for easy operator interface. In addition, all CSM RTO
systems are pre-wired, pre-piped and tested at the manufacturing facility
prior to shipment.
Recuperative Oxidizers
When appropriate, CSM thermal oxidation systems use a
recuperative air-to-air hear exchanger to pre-heat the VOC-laden stream by
recovering heat from the thermal oxidizer's clean hot exhaust, which can
reduce operating costs significantly. Up to 70% heat recovery can be
achieved with a fully welded, stainless steel, fin-and-plate or
shell-and-tube, air-to-air, recuperative heat exchanger from CSM. Our
selection features low pressure drop, compact and modular construction, and
high heat recovery efficiency.
Direct Thermal Oxidation and Scrubber
For 99.9% destruction efficiency of highly toxic materials,
CSM offers our direct thermal oxidizers, followed by Quench and Scrubber.
This type of oxidizer is designed for applications of low flow rates and
high operating temperatures. Compounds in the effluent from the oxidizer
could be acid gases of halogens, nitrates or sulfides. CSM's Quench and
Scrubber technology has a proven track record of years of successful,
continuous operation.
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