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JE/DE Quize #8
Auxiliary Boilers
Question | Answer |
---|---|
1-Describe the function of the photo cell detector with respect to the combustion control system. | Provide voltage signal for substain burner ignation |
2-Why do we shut the manually operated fuel valves prior to performing any work on an automatically fired auxiliary boiler? | Prevent fuel leaks |
3-What happens when a component fails and the flame safeguard control for an automatically fired auxiliary boiler? | Prevent Automatic restart |
4-How does the flame scanner output at high compare to it's output at low fire? | it's proportional to the flame size |
5-What could happen to the feed pump suction if the feed water is to hot? | Loss of suction resulting in loss of feed flow to the boiler |
6-A successful pre-purge is dependent upon what two components? | Damper position and proper air flow |
7-Describe what happens to the flame of an automatic boiler when the steam pressure is higher than the normal operating band. | Lost of fire, fuel valve shuts down |
8-If a boiler is equipped with a low level probe senor, what will happen if the water level drops below the level of the low level probe? | Sensor actives alarm, boiler shuts down |
9-Why due we maintain pH within the range specified by the manufacture? | Reduce corrosion rate |
10-If fuel is shutoff due to flame-out on an automatically controlled boiler, what does 46CFR require? | require both Visual & Audible alarms for flame- out |
11-Describe the fusible plug on a Scotch or auxiliary boiler | Located at or near the center of the crown sheet of the combustion chamber |
12-How is the fuel atomized for use when using a steam atomizer | Steam expansion atomizes the fuel (which occurs inside the furnace) |
13-List the seven system required by 46CFR63 For Large Automatically Controlled Auxiliary Boilers | 1-Program control system ,2-Operating control system,3-flame Safeguard control system,4-Limited control system,5-Combustion control system, 6-Fuel Supply control system,7-Ignition System. |
14-List the three steps in the procedure for replacing tubes in a water tube auxiliary boiler. | rolled, beaded and seal welded |
15-Why is it important for safety valves to open and close rapidly? | prevent wire drawing (which is the edging of the disk) |
16-46CFR61 Requires that auxiliary boilers that have undergone major repairs be hydrostatically tested to what percentage of their operating pressure? | 150% |
17-Why do we purge boiler furnaces proir to light the fire? | prevent explosion by removing combustible gases |
18-List the major cause of heavy soot accumulation in auxiliary boilers | frequent cycling |