This month we've been comparing FTA vs Catalytic for process applications...now let's see it in action!
A customer of ours who produces high performance materials, industrial specialty chemicals and coating solutions, was using a catayltic sensor where a flammability analzyer would be more beneficial.
Acrylate monomers, styrene and vinyl acetate monomer are used to produce their products. The off‐gas from the polymerization process is collected in a vent line and sent to an RTO for oxidation. They continuously check the %LFL of the mix of monomer vapors in the vent line. If the LFL goes over 25% they bypass the RTO and send the high LFL stream to a caustic soda scrubber and active carbon filters without any ignition source. They also purge the duct with nitrogen starting at the RTO and up to the emergency vent. They do not want a high LFL stream to reach the combustion chamber of the RTO.
The Company was using a catalytic sensor to monitor the LFL of the off‐gas vent stream. However there was a 25 second response time!
As we talked about a few weeks ago a slow response like that is reason enough to eliminate a catalytic sensor from consideration as a process monitoring device. 25 seconds is just too long to prevent a high LFL stream from going into an RTO.
A flammability analyzer on the other hand has a less than 1-second response time. It can be mounted directly on the process duct without heat trace sample lines, pumps, or blowers, eliminating the unpredictability of moving parts and shortening the sample path significantly. This radically reduces sample delivery time, while ultimately accelerating response time.
Our customer chose to install a Flammability Analyzer on their off‐gas vent stream, so it can react quickly to divert a high LFL stream from going to the RTO. They've been successfully using these analyzers for more than a year.