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Troubleshooting - Fresh Water Generator




Problem
Cause
Solution
Distillate generation rate has dropped
Inside the heating tube is fouled up.
Clean the heating pipe.
Inside the condenser piping is fouled up.
Clean the condenser piping.
Hot water temperature is low.

Hot water flow rate is low.
Increase the hot water flow rate.
Cooling water flow rate is too low.

Sight glass is filled with water.

Degree of vacuum in evaporator has dropped.

Evaporator temperature has dropped.
Hot water temperature is low.
Increase the temp to the specified level
Hot water flow rate is low.
Increase the hot water flow rate.
Degree of vacuum in evaporator has dropped.
Air is leaking.
Repair the leaking area and preform air test at 0.05Mpa.
Water ejector has malfunction.

Water ejector has malfunction.
Nozzle is clogged.
Clean the nozzle.
Diffuser has been corroded or worn out.
Replace with new one.
Nozzle has been worn out.
Replace with new one.
Outlet pressure is 0.08Mpa or higher
Check for clogging of the ejector outlet piping; Check the valve opening of overboard discharge valve.
Outlet pressure is negative.
Somewhat close the overboard discharge valve.
Sight glass is filled with water.
Distillate pump has failed.
Repair the distillate pump.
Distillate pump outlet valve is in close position.
Open the distillate pump outlet valve.
Outlet piping is clogged.
Clean the outlet piping.
Distillate pump is drawing air.
Replace the mechanical seal.
Salinity of distillate is too high.
Distillate generation rate is too high.
Decrease the hot water flow rate.
Evaporating temperature is too low.(50·C or lower)
Somewhat close the vacuum adjust valve to increase the evaporating temperature.
The fresh water generator has been used in port or river mount, and the feed water is dirty.
Stop running the fresh water generator.
Indication on the salinity indicator is faulty.
Check using the salinity indicator test switch.
Clean the cell (electrode).
Condenser piping has been damaged.
Plug the failed pipe.
Feed water flow rate is lower than specified level.
Opening of the feed water adjust valve is insufficient.
Adjust the opening of feed water adjust valve.
Feed water orifice is clogged.
Open and clean the feed water orifice.
Internal pressure on the condenser piping is insufficient.
Somewhat close the condenser cooling water outlet.
Feed water flow rate is higher than specified level.
Opening of the feed water adjust valve is more.
Somewhat close the feed water adjust valve.
Feed water orifice has been worn out.
Replace the feed water orifice.
Pump does not start
Motor or electrical system has failed.
Inspect and repair
The pump has seized. Impeller has seized with casing ring.
Replace or repair the impeller; replace the casing ring.
Pump has failed to attain the specified capacity and head.
Pump is drawing air.
Check the suction system. Retighten.
Suction strainer.
Clean.
Impeller passage is blocked.
Clean.
Motor running in reverse direction.
Correctly connect the wires.
Motor speed has dropped.
Check the electrical system.
Clearance to the casing ring has increased.
Replace the casing ring; repair or replace the impeller.
Impeller has damaged.
Replace the impeller.
Water flows immediately after startup, but soon stops.
Air is trapped in the suction pipe.
Vent the piping.
Air is drawn through stuffing box.
Inspect the mechanical seal.
Motor is overloaded.
Bearing has been damaged.
Replace the bearing.
Motor is misaligned with the pump.
Adjust the centering.
Shaft has been deformed.
Replace the shaft.
Motor or electrical system is faulty.
Inspect and repair.
Amount of discharge is too much.
Somewhat close the discharge valve.
Pump is vibrating.
Impeller is not balanced.
Repair or replace the impeller.
Bearing has damaged.
Replace the bearing.
Motor is misaligned with the pump.
Adjust the centering.
Shaft has been deformed.
Replace the shaft.

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