boilers you will be assigned to operate. For specific operating instructions, consult the manufacturer's manual for the boiler concerned.
During normal operation of boilers, the operators have two major responsibilities. First is to maintain proper water level at all times. If the water level is too low, tubes may overheat, blister, and rupture. If water level is too high, carry-over of water to the superheater tubes may damage the superheater elements and the turbine. The second is to prevent loss of ignition when burning fuel is in suspension. Maintain safe and efficient combustion conditions in the furnace and correct fuel-air ratios.
Establish definite intervals for blowing down the boiler, depending on the type of operation and chemical analysis of the boiler water. During regular operation, never blow down economizers or water-cooled furnace walls. Blowdown valves on this type of equipment serve only as drain valves.
Blowdown should be at reduced or moderate rates of steam for low point drains or blowdown valves. When the water glass is not in full view of the operator blowing down a boiler, another operator should be temporarily assigned to observe the water glass and signal the operator handing the valves. For control of water conditions when working, use continuous blowdown to maintain the proper concentration at all times and to prevent blowing down large quantities of water while the boiler is operating at a high capacity.
Use only properly treated water for makeup, and maintain the boiler water conditions as specified in water treatment instructions. Make an accurate water analysis at specified intervals. Carefully control the blowdown and the addition of treatment chemicals to meet the manufacturer's specifications.
Remove soot from hoppers and pits at definitely established intervals, as necessary.
Establish definite intervals for observing and recording the readings on all important instruments and controls. Be sure you obtain accurate readings-and see that the readings are recorded properly on the log sheet or other required record.
To help ensure efficient operation of the boiler, operators should ensure that proper operating checks are done during boiler operations. Operating checks, as shown in table E, appendix II, apply to most, if not all boilers.
Keys to efficient boiler operation and performance are as follows:
1. Flue-gas temperature
a. Keep the temperature low.
b. Temperature should be about 150 degrees higher than temperature of steam produced.
2. Flue-gas analysis
a. Take periodically.
b. Maintain proper CO;! level for fuel used.
a. Should be long and lazy.
b. Must not enter the tubes.
c. Not dark and smoky.
d. Have a light brown haze from stack, except gas.
e. When the fuel is oil, have a yellow flame with dark or almost smoky tips.
a. Usually 0.03-0.06 inch of water.
b. Check the manufacturer's recommendations.
5. Makeup feed
a. Maintain low rate.
b. Avoid excessive boiler blowdown.
a. Ensure boiler and lines are well insulated.
7. Water treatment
a. Carry out prescribed treatment of boiler water.Continue Reading