Hello All,
We have a peculiar problem.
We have 2 furnaces sharing a common forced draft fan. The situation is as follows, operations are requesting that if one of the 2 furnaces trip to keep the FD fan on. The idea is to allow one of the 2 heaters operating and to avoid a total shutdown of the unit. It is understood however, that under specific scenarios like, hydrocarbon detection in the FD fan inlet or push button ESD, the FD fans will trip with the heater.
My concern with this is that it is still unsafe based on the following,
Maintaining the heater and FD fans online during a flame out:
The fuel gas mixture can/may ignite if it hits a hot spot on the refractory, resultiing in an explosion, fire. Feeding combustion air to this scenario will exacerbate the situation.
Maintaining the heater and FD fans online during a tube leak:
A tube leak due to a line rupture, can result in a fire. Adding combustion air to a fire will worsen the situation.
The obvious solution is for each heater to have its own balanced draft system,
Your feedbacks on whether, FD fan can remain online after a furnace trip would be much appreciated.
We have a peculiar problem.
We have 2 furnaces sharing a common forced draft fan. The situation is as follows, operations are requesting that if one of the 2 furnaces trip to keep the FD fan on. The idea is to allow one of the 2 heaters operating and to avoid a total shutdown of the unit. It is understood however, that under specific scenarios like, hydrocarbon detection in the FD fan inlet or push button ESD, the FD fans will trip with the heater.
My concern with this is that it is still unsafe based on the following,
Maintaining the heater and FD fans online during a flame out:
The fuel gas mixture can/may ignite if it hits a hot spot on the refractory, resultiing in an explosion, fire. Feeding combustion air to this scenario will exacerbate the situation.
Maintaining the heater and FD fans online during a tube leak:
A tube leak due to a line rupture, can result in a fire. Adding combustion air to a fire will worsen the situation.
The obvious solution is for each heater to have its own balanced draft system,
Your feedbacks on whether, FD fan can remain online after a furnace trip would be much appreciated.