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We are proud of our
newest proprietary product - Slag-Be-Gone which is designed to
help eliminate slag in boilers. Long a costly problem, our new
product saves both money and equipment by eliminating costly
repairs.
Based on different mechanisms involved in ash deposit on the heat
surface, two general types of ash deposition have been defined as
slagging and fouling. Slagging is the formation of molten or
partially fused deposits on furnace walls or convection surfaces
exposed to radiant heat. Fouling is defined as the formation of
deposit on convection heat surfaces such as superheater and
reheaters.
Slag formed when melt or soften ash particles is not cooled down to
solid state when they reach the heat surface. Typical initial
deformation temperatures (or so called “ash fusion” temperatures)
are 2100 to 2200 F. With furnace gas temperatures in excess of 2500
F, we have semi-molten ash that may stick to the relatively cooler
walls. Most ash tend to be resolidified due to the relatively lower
temperature at the tube surface and the particles factures on impact
and partially bounce back into the gas stream. However, if the
furnace is too small, the exit gas temperature is too high or the
melting point of ash is relatively low, molten ash may not have
enough time to be resolidified when they hit the heat surface,
therefore they are easy to stick to the surface and cause the
accumulation of deposits leading to slagging. Depending on the
strength and physical characteristic of the deposit, steam or air
sootblower may be able to remove most of them. However, the base
deposit generally remains attached to the tube, allowing subsequent
deposits to accumulate much more rapidly.
Fouling is generally caused by the vaporization of volatile
inorganic elements in the coal during combustion. When heat is
absorbed and temperatures decrease in the convection area of the
boiler, compounds formed by these elements condense on ash particles
and heating surface, forming a glue which initiate deposition.
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