Thermal Oxidizer Optimization

Optimizing the thermal oxidation process is a balancing of the three primary variables of combustion - time, temperature and turbulence.

The easiest and most direct optimization variable to measure and control is temperature.   CleanAir can perform temperature measurements to verify control sensor accuracy, provide a thermal profile of the combustion chamber to monitor temperature stratification, and calculate heat exchanger efficiency.   Our goal is to reduce the operating temperature while maintaining oxidizer performance - thereby reducing fuel, heat stress and long-term maintenance costs.

In addition to temperature, other parameters such as volumetric flow rate, CO, NOx and VOCs may provide key insights into possible optimization strategies for oxidizer systems.

Design limit deviations affect the retention time and pressure drop of the system.   Both are key variables in the combustion efficiency equation.   Volumetric flow measurements will verify if your control system is operating within design specifications.

CO values give an indication of heat exchanger integrity and combustion efficiency.   Thermal stress on heat exchangers can cause cracks to develop in the metal welds and seals, allowing process gases to leak directly to the exhaust stack.   These gases may be partially oxidized, forming CO and other products of incomplete combustion.

Oxides of nitrogen give an indication of the burner condition.   NO and NO 2 are formed at temperatures in excess of 2000°F.   These conditions exist only within the burner flame of the thermal oxidizers.   Poor burner efficiency may also contribute to CO formation.

The measurement of volatile organic compounds, or VOCs, provides the information needed to calculate the destruction efficiency of the thermal oxidizer.   Depending on the compounds being oxidized it may be necessary to utilize sophisticated measurement techniques such as the FTIR or GC/MS.   Products of incomplete combustion can be identified providing detailed information on the probable cause of oxidizer problems.   However, we must ensure that in our attempts to meet these conditions, other regulated Hazardous Air Pollutants are not unintentionally formed by improperly operating the control equipment.