Increasingly stringent air quality requirements have led to expanded use of wet scrubber systems to control pollutant gases released as air emissions. Chlorine storage facilities and chemical process plants are frequently required to scrub exhaust gas streams to remove halogen and acid gases. Unfortunately, monitoring reactive gas concentrations in moisture saturated air streams presents problems for standard diffusion gas sensors. Condensing water in these air lines can quickly blind standard diffusion transmitters, rendering them inoperable.
PTT’s Wet Gas Detector was developed to meet the need for reliable measurements in wet scrubber outlets for other gas streams that might be saturated with water vapor. Gas detector systems have been developed for monitoring strong oxidants (chlorine, bromine, chlorine dioxide, or ozone), acid gases (HCl or HF), and hydrogen.
The basic Wet Gas Detector system consists of a loop-powered 2-wire transmitter and a corrosion resistant sensor specifically engineered to operate at 100% RH. Gas sensors are designed for direct insertion into vent stacks, or may be used in a flow-cell if a sample can be pumped to the sensor. When remote display and alarm relay functions are required, the wet gas transmitters can be connected to PTT’s Gas Alarm Module. This receiver system will provide direct digital display of gas concentrations, plus 3 alarm set points, a remote alarm reset input, and retransmitted 4-20 mA output. The wet gas transmitter may also be used separately and tied directly to the user’s DCS, PLC, or other equipment. Either way, the Wet Gas Detector is an excellent solution to a difficult gas monitoring problem.