Exhaust Fan; Ash Removal - Max-Ox MX-900B Operator's Manual

Exhaust Fan (Induced Draft):
A variable speed exhaust fan, referred to as an "Induced Draft" fan, is
mounted on the exhaust connection of your heat exchanger. This
variable-speed electric fan serves to pull fresh combustion air through
both the primary and secondary combustion air pre-heater sections, and
into the combustion chambers, pulls all combustion gases through the
combustion chambers and heat exchanger, pulls particulate laden flue
gas through a high efficiency cyclone dust collector, and then pushes
the combustion exhaust gasses (including water vapor) up the chimney
and out into the atmosphere.

Ash Removal:

As a solid fuel, wood is perhaps the best renewable fuel on the planet
from a "minimum ash content" perspective because wood has less than
1% ash content by weight (example: Oak = 0.15% ash by weight). For
the sake of comparison, coal mined in the United States ranges from 5%
to 20% ash by weight. When compared to coal ash, wood ash is much
more soft, fine, and fragile, and as such becomes airborne more easily.
Your MX-900B ash removal system has been designed to address wood
ash removal as follows:
Rotating Ash Ring, Ash Plow, Ash Auger & Ash Bin: The burning
surface of the fuel bed situated on top of the ring grate converts the
resinous lignin (sap) and solid fixed-carbon in the wood into flammable
gases, leaving behind non-combustible minerals as "ash". As fresh fuel
is pushed out of the center of the stoker mouth and onto the ring grate,
the ash which has formed around the perimeter of the burning pile is
pushed further out-board away from the ring grate, and onto a slowly
rotating solid ring, called the "ash ring".
Ash Plow: a fixed-position diagonal plow blade located above the
rotating ash ring scrapes ash material into an ash trough as the
ash ring rotates beneath the plough.
Ash Auger: A variable speed, motor-driven ash auger, situated in
a trough located out-board and slightly below the rotating ash
ring, receives ash scraped off of the ash ring by the plough. The
Max-Ox™ MX-900B Operators Manual, Rev. 0
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