The working principle of oil and the cause and solution of oil running

The working principle of oil and the cause and solution of oil running

                                oil separation tank is a pressure vessel that separates the compressed oil and gas mixture.

          There is an oil separation , return pipe, safety valve, minimum pressure valve, pressure gauge, etc. are installed on the tank.

The high-pressure, high-temperature (about 80°C) oil-gas mixture from the main engine enters the oil-separating tank along the tangent direction inside the oil-separating tank. Under the action of centrifugal force, most of the oil in the oil-gas mixture is thrown onto the inner wall of the oil-separating tank. Under the action of gravity, it flows along the inner wall to the bottom of the oil separation tank. Another part of the oil droplets condense into large oil droplets in the process of colliding with each other, and finally sink to the bottom of the oil separation tank under the action of gravity, and continue to participate in the circulation. The air filtered by the oil separation core passes through the minimum pressure valve, flows to the rear cooler for cooling, and then exits the air compressor.

During the use of the air compressor, sometimes there will be oil leakage, improper installation of the oil, and defects in the design of the oil and gas separation system.

(1) Excessive fueling: The fueling volume exceeds the normal oil level, and part of the engine oil is taken away with the airflow, resulting in excessive fuel consumption.

Solution: After stopping the machine, open the oil drain valve and drain the oil to the normal oil level after the air pressure in the oil and gas barrel is released to zero.

(2) Damaged oil return check valve: If the oil return check valve is damaged (from one-way to two-way), the internal pressure of the oil separator tank will pour a large amount of oil back into the oil separator through the oil return pipe after shutting down.When the machine runs next time, the oil in the oil separator will not be sucked back into the machine head in time, causing part of the oil to flow out of the air compressor along with the separated air.

(This kind of situation is common in machines without the oil stop valve and the machine head exhaust outlet check valve).

Solution: After the check valve is removed, if there is debris to jam it, remove the debris and clean it. If the one-way valve is damaged, check and replace it with a new one.

(3) Minimum pressure valve failure: If there is a leakage point in the seal of the minimum pressure valve or the minimum pressure valve is opened in advance (due to the different opening pressures designed by various manufacturers, usually the range is between 3.5-5.5kg/cm²), then the machine In the early stage of operation, the time to establish the pressure of the oil and gas tank will increase. At this time, the gas oil mist concentration in the low pressure state is high, the flow rate is fast when passing through the oil, the load of the oil is increased, the separation effect is reduced, and the fuel consumption is large.

Solution: Repair the minimum pressure valve and replace it if necessary.

(4) The oil return line is blocked: When the oil return line (including the check valve and the oil return filter on the oil return pipe) is blocked by foreign matter, the separated oil condenses at the bottom of the oil separator and cannot return to the machine head. The solidified oil droplets are blown up again by the airflow and taken away with the separated air. These foreign objects are usually caused by solid impurities that fall off during the installation process.

Solution: Stop the machine and remove all pipe fittings of the oil return pipe after the pressure of the oil drum is released to zero, and then blow out the blocked foreign matter. When installing the built-in oil separator, pay attention to clean the oil and gas barrel cover, and pay attention to whether there are solid particles at the bottom of the oil separator .

(5) Improper installation of the oil return pipe: When replacing, cleaning, and repairing the air compressor, the oil return pipe is not inserted into the bottom of the oil separator (reference: 1-2mm from the bottom arc center of the oil separator is better), resulting in the separated oil cannot be returned in time In the nose, the accumulated oil will run out with the compressed air.

Solution: Stop the machine and adjust the oil return pipe to a reasonable height after the pressure relief is reset to zero (the oil return pipe is 1-2mm away from the bottom of the oil separator, and the oblique oil return pipe can be inserted into the bottom of the oil separator).