MIL-HDBK-1003/6
m = PA/70
(100+14.7) x (B x (5/16)2/4) = 0.126 lbs/sec
m=
S))))))))))))))))))))))))))))))))))))))))))))
70
steam requirements = 0.126 lbs/sec x 20 sec x 7 blowers = 17.6 lbs/cycle
Use the following rule of thumb when estimating steam requirements
(by weight) for steam soot blowing systems. For coal fired boilers use two
percent of the units generated steam. Both dry air and dry steam can use a
blowing pressure of 120 psig (828 kPa). The minimum allowable operating
pressure is 80 psig (552 kPa) and the maximum allowable pressure (for power
boilers) is 300 psig (1 725 kPa). The soot blower manufacturer will determine
the blowing pressure required for the fuel, boiler design, and firing
conditions.
Where an economizer or air preheater is involved care must be taken
to avoid lowering flue gas temperature below the dew point. Moisture in steam
or air will form deposits in the economizer or preheater. Do not use steam
soot blowers in HTW boilers.
10.4.5
Operation
10.4.5.1 Steam Soot Blowers. Valving shall be provided to allow draining of
the supply steam lines prior to operating soot blower. Steam traps shall be
installed at low points in the soot blowing supply line to eliminate
condensate build up. This is necessary to assure no condensate has
accumulated in the soot blower prior to blowing. A shut off valve shall be
provided at each soot blower.
Air Soot Blowers. Do not run supply air piping in a way that
10.4.5.2
allows oil pockets to accumulate at or near soot blowers. Mixing of oxygen
and oil may cause an explosion in a hot boiler when soot blowers are operated.
10.4.6
Controls
Shop Assembled Boilers. On shop assembled boilers, and field-
10.4.6.1
erected boilers, of less than 200,000 lbs/hr (25.2 kg/s), soot blowers shall
be locally operated with local push-button stations for individual soot
blowers.
Field-Erected Boilers. On field-erected boilers greater than
10.4.6.2
200,000 lbs/hr (25.2 kg/s), the soot blowing system shall be an automatically
programmable control system. This system will automatically start and stop
each soot blower in a programmable sequence, monitor, and identify operating
soot blower. This control system will be centrally located in the central
control room or operator's control station. Local and remote manual override
control will permit manual start-stop operation of soot blowers. Local
control shall have highest priority.
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