What is back pressure in a purifier？

Back pressure in a purifier refers to the pressure exerted by the discharge line, which opposes the flow of separated liquids (water and oil) from the purifier bowl. It is an important parameter in the operation of centrifugal purifiers, which are used to separate impurities, water, and sludge from oil or other liquids.

Role of Back Pressure

- Maintains Proper Separation: The back pressure helps control the liquid levels inside the purifier bowl, ensuring that the oil-water interface is positioned correctly for effective separation. It prevents oil and water from mixing again after being separated.

- Prevents Water Leakage into Oil Outlet: By maintaining appropriate back pressure, the system prevents water from exiting through the oil outlet. If back pressure is too low, it may cause improper separation, leading to water leakage in the cleaned oil.

Factors Affecting Back Pressure

- Discharge Line Resistance: Any resistance in the discharge line, such as bends, valves, or partially clogged filters, can affect the back pressure.

- Flow Rate: The rate at which the separated fluids are discharged also influences back pressure; higher flow rates can increase it.

- Temperature: Changes in the temperature of the oil being purified can affect viscosity, which in turn influences the flow characteristics and back pressure.

Adjusting Back Pressure

- It is usually controlled by a valve on the discharge line of the separated liquids.

- The back pressure setting must be adjusted according to the manufacturer's guidelines to achieve optimal separation.

Maintaining the correct back pressure is crucial for the purifier to function effectively, ensuring high-quality separation and preventing contamination of the cleaned oil.