Alternate Heating COAL GUN S130, Installation And Operator'S Manual

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How Draft Controls Work
1. Static pressure from the cooler air around the
boiler exerts pressure on the outside of the furnace
or boiler, the breaching, and the stack.
2. /e pressure diDerence between the room air
and hot exhaust gasses causes products of
combustion to @ow (draE) through the unit and to
rise through the breaching and chimney.
3. When draE reaches a value higher than the
se ing of the control, room temperature air enters
through the barometric draE control in the precise
amount needed to overcome the excess draEs caused
by temperature variations, wind @uctuations and
barometric pressure changes.
4. Combustion of fuel is completed and the
process is stabilized. /e velocity of combustion
gases through the heat exchanger is slowed so more
heat is extracted. /e unit operates more eIciently,
reliably and requires less maintenance.
Draft Control
Choosing the Right Size Draft Control
If a barometric damper is required, use these
simple rules of thumb to guide size selections:
1. Use a draE control the same size as the @ue
pipe, that is, a 6" control for a 6" round pipe, a 12"
control for a 12" pipe, etc.
2. For intermediate sizes of smoke pipe, use the
next larger size draE control to provide ample
capacity. It is a simple ma er to install a round
control on a pipe an inch or so larger or smaller than
the control.
3. If the @ue pipe or breaching is square, use the
round equivalent. For example - on a 14" x 14"
breaching use a 14" control. Li le @ow occurs in the
corners of a square pipe so that its capacity is
approximately the same as a round pipe of the same
diameter.
4. If the breaching is rectangular or oval,
compute its cross-sectional area and select a draE
control having the same or a greater nominal cross-
sectional area. A breaching 14" high x 10" wide
would have a cross-sectional area of 140 square
inches. From the table, select a 14" control with a
cross-sectional area of 154 sq. inches.
5. Where a control larger than 32" is required, use
more than one regulator with combined cross-
sectional areas equal to or greater than that of the
- 6 -
NOTE: See diagram below which has been
modified for this manual.
If the draft regulator is set too high
it can cause the coal fire to burn out
of control.