Recently, ProcessBarron was contracted to manufacture custom Heat Recovery Steam Generators (HRSG) isolation doors.
The “Isolation Door” concept came about when ProcessBarron was approached by an engineering group in North Carolina to supply a guillotine or slide gate damper to isolate HRSGs if and when they failed.
At first, we declined the request for a bid due to the extreme temperatures involved (2200 deg F). The client then asked if there was anything else we could offer. We began working on an idea, and after a week, offered the concept of an isolation door to the client. This would be a short section of duct with the top portion actually being a hinged door that could be rotated downward to seal off the hot side of the system. The hot gases in the HRSG would vent to atmosphere, thus keeping the components of the failed unit from being destroyed. The door would close in 7 to 8 seconds when an HRSG failure tripped an alarm.
The main thing that makes this idea successful is that all of the exposed metal components of the door itself, such as bearings, shafts, and door supports, are out of the gas stream, unaffected by the high temperatures. Also, the exposed surfaces of the door are coated with heat reflective products to reduce any expansion and/or warping of the door when it drops to the down position and is exposed to a short-term blast of hot gases escaping the failed HRSG unit.
All of the internal refractory components and the innovative seals were developed by Bob Palmer of Empire Solutions and have proved to be very effective. Bob’s work on this project was immensely helpful.
Applications of HRSG Isolation Doors
We believe that this product can be used in many different applications where equipment needs to be protected against high temperatures in emergency situations or maintenance programs. We have supplied 12 large units to an energy company in Ohio and are projected to supply several to their plant in Granite City. Some of these units have already been actuated during HRSG failures and successfully prevented further damage. We also have supplied three smaller units to an engineering company in Kentucky for a pellet mill operation.