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

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for the control of solids through the use of blow
down.
Another test that is sometimes used as a measure
of solids is to measure the chloride present in the
boiler water. /e ratio of chlorides in the boiler
water to that of the feed water can be used as a
means to determine the amount of blow down
required. /e chloride test is unsuitable for feed
water with low incoming concentrations, and the
concentrations in the feed water must be averaged
over time for accuracy.
High boiler solids will lead to foaming, priming,
surging, and carry over. /ese conditions may only
be overcome by proper daily blow down of the
boiler.
Alkalinity
/e alkalinity of boiler water should be
suIciently high enough to protect shell and plates
against acidic corrosion, but not so high as to
produce carryover. A minimum value for alkalinity
for adequate protection is 200 ppm.
High boiler alkalinity (in excess of 700 ppm)
should be avoided. Values higher than this can cause
the steel to become bri le.
Phosphates
Phosphates are used to react with calcium
hardness in the boiler water. In order for this
reaction to take place it is important to maintain a
Ph at a minimum value of 9.50. It is desirable to keep
the concentration of phosphates in the water to 30-
50 ppm to enable the complete reaction of the
phosphates with the calcium hardness entering the
boiler through the feed water.
Hardness
/e hardness of water is caused by calcium and
magnesium ions. Water hardness will vary greatly
throughout the country depending on the source of
the water.
In boilers hard water can cause the formation of
scale and sludge or mud. /e hardness must be
removed in the makeup water to the return system.
Total hardness should not exceed 50 ppm.
Oils
Every eDort should be made to prevent oils from
ge ing into the boiler water. Oil causes foaming or
combines with suspended solids to form a sludge,
which can cause the overheating of boiler plates.
If oil does get into the boiler, the boiler should
immediately be taken out of service and thoroughly
cleaned.
Antifreeze
Antifreeze use is recommended where there is
any danger of the boiler water freezing. /e Coal
Gun vessel warranty does not apply to freeze
damage. Use concentrations consistent with
antifreeze manufacturer recommendations, but do
not use pure antifreeze in your system. Glycol-water
mixtures expand more than straight water, and may
lead to a requirement for increased expansion tank
capacity over that otherwise used for straight water.
Antifreeze usage, particularly containing ingredients
other than propylene glycol, is oEen prohibited by
homeowners’ insurance.
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Note: Low flash points for some antifreeze
products create a fire hazard when pure
antifreeze is used.