Control Instruments Corporation

Gas detection analyzers for pollution control - Air and Climate - Air Pollution Treatment

Government and environmental groups are forcing industries with medium to high VOC exhausts to reduce emissions by as much as 98%. Incineration using pollution control devices such as oxidizers and flare stacks is one way to bring the exhaust emissions in line with the regulations. Capturing and reusing solvent in a solvent recovery system is another way.


A flame ionization detector at the outlet of the oxidizer ensures that it does not exceed emission levels. In addition, by using two flame ionization detectors, one on the inlet and, one on the outlet hydrocarbons can be measured and compared before and after processing, indicating efficiency.

Our Model SNR650 was designed specifically for industrial use and is the only FID that mounts directly on the oxidizer rather than in the instrument or control room. This greatly improves response time and eliminates the expensive heat-traced sample lines required by other FIDs. The analyzer meets the performance criteria of CFR 40 Part 60, method 25A.

The National Fire Protection Associations’ (NFPA) Standard for the Safe Operation of Ovens and Furnaces defines direct-fired thermal oxidizers as Class A Furnaces mandating the use of continuous flammability analyzers on the inlet streams exceeding 25%LFL. Measuring flammability at the inlet of the oxidizer will prevent fires, explosions, or catalyst destruction by monitoring the flammability of the incoming VOC stream. These streams are of varying energy content that can change rapidly in a matter of minutes. Danger is present when the inlet stream suddenly gets rich enough to ignite or explode.

Our PrevEx Flammability Analyzers are used on the inlet duct to monitor the flammability of the incoming stream and protect it from dangerous concentrations caused by rich vapor streams. It is the only gas detection system that meets all the requirements of the NFPA.

Incineration/ Flare Stacks

US EPA code 40 CFR 60.18 states that for optimum destruction efficiency in flare stacks, the waste stream must run at a minimum heating value of 300 BTU/SCH. Continuous monitoring of the waste stream is necessary to identify the minimum heating value and ensure proper combustion.

Our CalorVal BTU Calorific Analyzer provides a continuous, direct measurement of the heating value with a very fast response time. It has a universal response to a wide range of combustible gases and vapors, including heavy hydrocarbons, carbon monoxide, hydrogen and numerous other compounds found in waste gas streams. In addition, the presence of non-combustible compounds such as carbon dioxide, nitrogen and water vapor do not interfere with the BTU readings of the remaining combustible compounds.

Solvent Recovery

Solvent recovery systems recover and re-use solvents from manufacturing processes. Solvent laden air from the processes is passed through an activated carbon bed. When the carbon bed is nearly saturated with solvent, a steam-down cycle occurs to condense out the solvent for re-use. The carbon is then regenerated for another collection phase. Two carbon beds are used so that one bed can process the solvent-laden air while the other one is regenerating.

Our SNR650 Flame Ionization Detector monitors the hydrocarbon levels of the carbon beds in real time and reacts quickly to switch beds, allowing for optimum performance.