Stokers; Hand-Fired Plants - Field Controls M Manual

STOKERS

After the draft control is installed, start a fire. When the fuel bed reaches a normal depth, at least 6" to 10"
deep, the draft can be set. The adjusting must be done while the stoker is running and its fan adjusted to
approximately the correct setting.
When a draft gauge is available, the readings should be taken over the fire (that is, in the fire box or
combustion chamber) through a small hole in the fire door. If the draft tube is inserted through a slide in door,
it is best to insert the tube through a piece of paper to prevent a rush of air around the tube. For a domestic
stoker in a home, the draft should be set at .04" OVER THE FIRE, with the STOKER ON, and for a somewhat
larger plant .06" to .08" usually is sufficient. Have just enough draft so that at the moment the stoker starts,
it does not gas or puff back into the room through cracks around the fire door (with the fire door closed). If
there is objectionable smoke, increase draft slightly.

HAND-FIRED PLANTS

The controls from the 6" to the 12" size, inclusive, are pre-set at the factory for approximately the correct
draft (.06") for the majority of installations. In most cases this will give sufficient draft for cold weather, with
reasonably quick pickup after a banked period, which means the control is probably set correctly.
However, if it seems advisable to change the adjustment, a good fire should be burning and the plant
operating. Close any check damper in the pipe and open wide the hand turn damper. If the plant
overheats, screw the weight on the control inward so that the gate opens more. But if there is not enough
heat, screw the weight outward, thus causing the gate to close more and maintain a stronger draft.
The 16" and larger regulators are not pre-set at the factory, and therefore have to be adjusted to suit the
needs of the individual plant.
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