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Observed problem |
|
Problem source |
|
Corrective measure |
| 1. |
Poor ejector performance, unstable operation, pressure swings |
1. |
Lower than design motive steam pressure |
1a. |
Raise motive steam pressure to the minimum specified by the ejector manufacturer |
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|
1b. |
Bore the motive nozzle to a larger diameter to permit design steam consumption-consult with manufacturer to determine proper nozzle diameter
|
| 2. |
Reduced ejector capacity and an increase in suction pressure |
2a. |
Higher than design motive steam pressure |
2a. |
Reduce motive steam pressure to specified pressure |
|
|
2b. |
Wasted steam consumption |
2b. |
Purchase new steam nozzles with smaller diameters designed for the higher motive steam pressure
|
| 3. |
Poor ejector performance, unstable operation, pressure swings |
3. |
Higher than design steam temperature, excessive superheat |
3a. |
Raise motive steam pressure |
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|
|
|
3b. |
Bore the motive nozzle to a larger diameter to permit increased steam consumption-consult with manufacturer to determine proper nozzle diameter
|
| 4. |
Low ejector discharge temperature |
4a. |
Reduced ejector capacity |
4. |
The motive steam is wet, therefore, steam piping must be insulated and a moisture separator and trap added in the motive steam line just before the ejector
|
| 5. |
Higher than design discharge pressure |
5. |
Poor ejector performance, unstable operation, pressure swings |
5a. |
Look downstream for problems that could be:
a) an intercondenser problem
b) an ejector problem
c) a restriction in the discharge piping
d) noncondensible gas load is above the design rating pressure
|
| 6. |
Higher than design suction pressure (assuming motive steam pressure and quality are normal and discharge pressure is equal to or less than design) |
6. |
Greater than design process load or mechanical problems with ejectors-either worn internals or possible internal steam leak around steam nozzle threads |
6a. |
Inspect internal dimensions and replace if necessary |
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6b. |
Tighten steam nozzle to steam chest if necessary or seal weld nozzle to steam chest
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