Boiler draft control manual#

The trick was to have the dampers allow enough air to keep up to swings caused by inconsitencies in the fuel or load changes.

Trim is just fine tuning.Typically though, the dampers would be trimmed by hand. In the bad old days when the fans would be driven with steam turbines then the furnace pressure would be controlled by the fan speed and trimmed by dampers. This would leave the furnace pressure to be controlled by the ID Fan/dampers.

Most systems have the air flow controled by the FD fan/damper and responding to the header or boiler pressure with the fuel feeder speed responding to the air flow. Typically balanced draught systems are set up to run the fan at a constant speed and use the dampers to control the draught. Not sure what fuel you are using but it sounds like wood waste. We are looking to put our FD fan on VFD system now, but how it will help on this type of boilers can any one explain Is there a problem with having VFD on these system. as normal practice in power plant the FD and ID fan to be in VFD. but why there is this back firing and puffing is happening to my boiler can any one explain. Why this is happening, switching either ways the system should be same. The set point before this was at 5.5 mmWc but now we had to run at 8.5 mmWc during soot blowing we have to bring the set point to 10 mmWc but still there is small back firing and puffing. we find there is some small back firing and puffing is happening. Where the ID fan speed is control by the draft pressure and the damper we set at 100 %. Damper is controlled with furnace draft pressure.īut after we have changed the system that my ID fan with VFD and damper is control manually.

Boiler draft control manual#

My ID fan was on manual control speed indicator with VFD damper controller. I have a problem with my boiler draft control system, my boiler is a Fluidized bed combustion FBC boiler & balance draft.