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Air compressor oil separator blockage? Let's analyze the possible reasons
- Dec 12, 2018 -

First, let's get to know the oilseparator. "Oil separator" has a variety of names, such as oil/gas separator, air/oilseparator, Oil fine separatorect. The screw air compressor has an oil/gas separating barrel, which together with the oil separator, forms the oil/gas separating system of the air compressor.


Oil and gas separation bucket is primary separation, also known as primary separation or rough separation. The oil mist mixture after the rotor compressor enters the oil-gas separation barrel through the cyclone channel. Oil droplets larger than 1 micron in diameter are separated from the oil mist under centrifugal and gravitational action, accounting for about 99% of the total oil volume.

Oilseparatoris fine separation, belonging to secondary separation. Oil droplets with diameter less than 1 micron can be separated from compressed air more cleanly, thoroughly and effectively through porous filter materials, which can also be called affinity coalescence method.

Analysis of Oil Blockage Fault: The oilseparatorused in screw injection compressor, scroll compressor and rotary vane compressor has differential pressure when it is newly installed. We call it initial differential pressure. Generally, the application standard requires that the initial differential pressure be less than 0.2bar as a qualified product. We know that oil has a useful life, because when it separates engine oil and compressed air, some fine impurities will stay on its filter material, blocking the filter micropore, resulting in excessive resistance, increasing the pressure difference inside and outside the oilseparator, increasing the power consumption of the air compressor, which is not conducive to energy conservation and emission reduction, but also will exist failure danger in compressor. Oil blockage is also called excessive pressure difference, that is, the pressure difference between before and after oil separatoris large. Therefore, when the difference between internal and external pressure of oil reaches a certain value, it needs to be replaced immediately. So how much pressure difference is called oil plugging fault? The data of pressure differential alarm set by different brands of air compressors are different, generally to 0.8-1.5 bar. Pressure differential alarm indicates that oil needs to be replaced.


Disclosure of common causes of oil blockage in air compressor:

Causes of Oil Blockage in Air Compressor 1: Ambient Environment of Air Compressor

There are corrosive gases in the environment around the air compressor. For example, in some cases, there will be sulfides, Banana oil, chemical agents for cleaning, etc. volatilizing in the air. The high temperature of the machine itself accelerates the oxidation of the oil. Once these gases enter the air compressor system and react with the oil chemically, resulting in carbon deposition and oil sludge, someimpurities enter the oil circulation system and are intercepted by the oil filter. The other part of impurities rise to the oil separator with the oil-gas mixture.When the gas passes through the oilseparator, these impurities stay on the oilseparator’s filter paper, plug the filter hole, and the resistance of the oil increases slowly, which makes the oilseparatorneed to be replaced in advance in a relatively short time.

Air compressor oil blockage failure reason 2: not using qualified air filters, oil filters, oil, one or more situations exist!

1. Air filterwith poor filtering accuracy will prevent some dust particles from being intercepted and directly enter the air compressor system. Oil filterand oilseparatorload will increase, resulting in premature blockage of oil filterand oilseparator.

2. Impurities, oil oxides and worn metal particles entering the air compressor system, due to the poor filtering accuracy of oil filters, some of them are intercepted on the filter layer of oil filters.Another part of the impurities in the machine cycle has been up to the oil separator after the separation, stranded in the filter layer of the oil separator, causing oil separator is blocked.Others use inferior oil filters for tens of hours, the bypass valve opens, and the oil is not filtered in the circulation system.

3. Oil with poor oxidation resistance should not be used. Even if the working time is short, it will produce carbon deposit and cavity, which will block up the oilseparator.


Air compressor oil blockage failure reason 3: air filter connection between the main engine intake pipeline leakage:

1. There are several reasons for the faulty sealing of the contact surface between the air filter and the air filter assembly.

(1) The air filter is not installed properly (the size is incorrect)

(2) The contact surface of the air filter assembly is uneven (the air filter assembly is deformed).

(3) There is dirt attached to the contact surface between the air filter and the assembly, which leads to leakage.

(4) The elastic contact pad on the surface of the air filter is put askew.

(5) Fracture of air filter or air filter assembly.

2. Leakage occurs in the middle of the intake hose:

(1) aging and rupture of intake hose.

(2) The intake hose is not installed properly.

3. Leakage of the seal at the connection between the intake valve and the nose may be caused by damage to the seal gasket or a misalignment.

Air compressor oil separator blockage failure reason 4: excessive water on oil separator filter material makes the filter material swell and shrink, reduces the effective separation area of oilseparator, causes oil separatorresistance to increase, oil separator blockage ahead of time.

1. Leakage of the minimum pressure valve. When the machine shuts down, the external air flow returns to the oilseparatorwith the leakage of the minimum pressure valve. As the pressure and temperature decrease at the same time, the gas condenses into water droplets, and the water droplets enter into the oilseparatorto make the filter water absorbent, swell and deteriorate.

2. User's gas consumption is small, the load time of air compressor is short, and most of the time is in no-load state. When air compressor is no-load, the water can't be discharged in time, and the water stays in the oil separator filter material.

3. The machine operates at lower than 75℃ for a long time, so that the moisture in the inhaled air can not be discharged and remains in the oilseparatorfilter material for a long time.

Above all, we listed four common causes of oil separator blockage in air compressor, hoping to help the vast number of air compressor users.