What is a gravity disc?
The gravity disc is an important part of the purifier, which set the location of the oil, and water interface line, which is variable according to the maker’s design.
How to choose the correct size of
gravity disc?
The correct size is selected using:
- Separation temperature
- The density of oil at this temperature
- Desired throughput of oil and by using of nomogram from the purifier manual.
What is a paring disc?
- It is a stationary impeller mounted in a chamber at the neck of the bow.
- Its function is to convert the rotating energy of the liquid into a pressure head.
What about water washing?
- Water washing is a widely used technique to remove acids, salts, and other impurities from the oil.
- The oil must be straight mineral oils or without dispersant additive oils.
- Water should be injected into the oil before purifying at a rate of between 3 to 5% of the oil flow that continuously renews the water seal in the purifier bowl.
- The oil temperature should be around 75 °C and the water temperature about 5 °C higher than the oil.
- It can be done continuously or intermittently.
What is steam jetting?
- By blowing steam into the engine lube oil just pair to its purification.
- Coagulation of colloidal carbon will occur.
- Purifiers will remove this carbon more effectively.
Compare purifier and clarifier ?
Purifier
- Remove water and suspended solids particles from oils
- Two outlets for water and clean oil
- Gravity disc on top
- Blind disc on the top of the disc stack
- Sealing water required
Clarifier
- Remove finer and lighter particles from the oil
- One outlet for clean oil
- No gravity disc only sealing ring
- Blind disc at the bottom.
- Sealing water is not required
How do you change purifier to
clarifier?
- Open up the purifier and set the blind disc at the bottom of the disc stack.
- The water outlet is blocked by a seal on the gravity disc.
- Blank off the sealing water inlet line.
What is purifier, clarifier ?
- A purifier is a centrifuge, which is arranged to separate water and solid impurities from the oil.
- The clarifier is a centrifuge, which is arranged to separate finer solid impurities from the oil.
How to change the purifier from HFO to
DO?
- Replace the gravity disc, which is smaller than the heavy oil
- Open heater bypass valve.
- Close the FO heater steam in/out valves.
- Open heater drains v/v.
- Pure DO purifier cannot change to HFO, it has no heater.
- A pure clarifier cannot change to a purifier, it has no water outlet.
Why is multidisc provided inside the purifier?
- To separate the liquid into a thin layer & create a shallow settling distance between discs.
- Improving separation of oil from heaver liquids & solids particle
Cause of excessive vibration on
purifier?
- Sludge too much inside the bowl
- Foundation damper & spring failure
- Bearing failure
- Worn gear
- Uneven wear of the frictional clutch
- Motor speed too high or too low
What are the reasons for purifier overflow?
- Incorrect purifier disc size (inside diameter too large)
- Too low fuel oil temperature
- Too much rate of throughput
- Too much sludge inside the bowl
- Low speed (rpm) of bowl rotation
- Sealing water failure
- Operating water failure
- Worn out the main sealing ring
Why purifier is not building up
speed while running?
- Improper touching with friction clutch (worn out frictional clutch)
- Touching with break
- Excessive sludge in the bowl
- Bearing failure
- Motor running at overload
- One phase power failure (Single phasing)
- Sump oil level too high
- The vertical shaft and horizontal shaft are out of alignment
How to adjust purifier bowl height?
- By shim by bowl body
Effect of reduced purifier bowl
height?
- Oil goes through the water outlet.
Why need sealing water?
- To seal the water outlet & to prevent the overflow of oil from the water outlet.
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