Learn and grow together with Shanghai fly and compressor every day! Generally speaking, oil running is closely related to the following factors: oil fault, compressor system fault, improper oil installation, oil and gas separation system design defects. If the compressor runs out of oil, it will not only contaminate the post-treatment equipment, such as the dryer and the precision filter element, but also affect the product quality, resulting in different degrees of damage to some production equipment. Therefore, it is necessary for us to master the cause and treatment of screw compressor fuel consumption.

Oil content of failure

Oil injection screw compressor, in the compression of gas at the same time, a large amount of oil is sprayed into the compressor between the teeth volume. The oil and gas mixture formed by the oil and gas compressed goes through the same compression process and is discharged into the oil and gas separator of the unit. Oil and gas separator is one of the main equipments in the system of oil injection screw compressor. In order to reduce the oil content in the exhaust and recycle the oil in the unit, the oil and gas separator must be used to separate the oil from the gas effectively. If the oil content fails, the oil will not be separated well and the oil will be discharged with the compressed air. Therefore, the oil content and the oil core fault is the main factor of the oil injection screw compressor.

The main causes of oil fault of compressor are as follows:

1. Oil wick clogging: when the oil wick clogging will cause the air pressure electromechanical flow large. It is also possible to deform the oil core due to excessive pressure, and the main engine will be locked if the motor is seriously overloaded. In addition, too much current can shorten the life of contactors or cause major accidents when contacts are burned to death.

2. The oil wick is broken. When the oil separation core is damaged, the air compressor will consume a lot of oil, and there will be a lot of oil in the gas storage tank and pipeline. In severe cases, air compressor oil will be directly discharged from the drain valve of air storage tank.

The main causes of this fault are:

Failure to replace oil separators on time;

Poor quality oil separation core is selected.

During the installation process, it was not operated according to the procedures, such as breaking the oil separation core when installing the oil pipe.

3. The oil core burned out. The burning of oil core is not common in the operation of air compressor, but it happens occasionally. The main performance is that the filter screen of the oil core is partially or completely carbonized, and even the metal shell of the oil core is burned.

The main reasons for such failure are:

Air compressor oil quality is poor;

The oil core itself is too poor quality;

When installing oil separator, there is no reliable connection between oil separator shell and oil separator barrel, which cannot be grounded. When there is static electricity, oil mist is ignited, thus burning oil separator.

4. The separation effect of oil core is poor. The main performance is the compressed air oil content is too large, the post-treatment equipment and user equipment caused damage.

The main reasons for this fault are:

The oil core itself is too poor quality;

It was not installed according to the procedure.

Other reasons

1, minimum pressure valve failure

Minimum pressure valve is to maintain a part of the screw compressor system pressure, if the minimum pressure valve seal leakage point or the minimum pressure valve opened ahead of schedule, so the machine at the beginning of the run build YouQiGuan pressure time will increase, at this point in a state of low pressure gas oil mist concentration is high, through the oil content in fast speed, oil load is aggravating, separation effect is reduced, cause a large fuel consumption.

Solution: repair the minimum pressure valve, replace if necessary.

2. Unqualified compressor lubricating oil is used

At present, the general screw compressor has high temperature protection, its usually skip temperature is 110 ~ 120℃ or so, and some compressor used unqualified lubricating oil, when the exhaust temperature is high, there will be different degrees of oil consumption (based on this, the higher the temperature, the greater the oil consumption). The reason is that at high temperature, after the primary separation of oil and gas barrels, some oil droplets can have the same order of magnitude with gas phase molecules, molecular diameter ≤0.01 micron, it is difficult to capture oil separation, resulting in high oil consumption.

Solution: find the cause of high temperature, solve the problem to reduce the temperature, as far as possible to choose good quality screw compressor lubricating oil.

3. The design of oil and gas separation tank is not standard

Some compressor manufacturers, in the design of oil and gas separation tank, the primary separation system design is not reasonable, the primary separation effect is not ideal, so that the oil before the oil into the fog concentration content is very high, the oil load is too heavy, the treatment capacity is not enough, resulting in high oil consumption.

Solution: manufacturers improve the design to improve the effect of primary separation.

4, too much gas

The refueling volume exceeds the normal oil level, and some oil takes away with the airflow, leading to excessive oil consumption.

Solution: after the shutdown, open the oil drain valve and discharge the oil to the normal oil level after the pressure relief in the oil and gas drum is zero.

5. Oil return check valve is damaged

If oil return valve damage (from ChanXiangTong to two-way communication), oil tank pressure after downtime will pour a large amount of oil through the return pipe to oil content inside, the next machine is running, oil inside the oil will not be able to timely sucked back into the nose, causing part of the oil with air to run to the outside of the compressor of the separated oil cut-off valve (this kind of situation is common in not device and machine head exhaust outlet check valve).

Solution: check the check valve after removing it. If there is any debris to jam it, clean up the debris. If the check valve is damaged, replace the new product.

6. Improper installation of return tubing

During the replacement, cleaning and maintenance of the compressor, the return pipe is not inserted into the bottom of the oil (reference: 1 ~ 2mm from the arc center of the bottom of the oil is better), resulting in the separated oil cannot be returned to the head in time, the accumulated oil will run out with the compressed air.

Solution: stop the machine, wait for the pressure relief to return to zero, adjust the return pipe to a reasonable height (the return pipe is 1~2mm away from the bottom of the oil distribution, and the return pipe with inclined mouth can be inserted into the bottom of the oil distribution).

7, large gas consumption, overload and low pressure use (or the oil distribution capacity selected before the machine leaves the factory matches the machine exhaust capacity too tight)

The use of load low pressure means that when the user USES the compressor, the exhaust pressure does not reach the rated working pressure of the compressor itself, but it can basically meet the gas requirements of some enterprise users. Business users, for example, increased the gas equipment, gas increases, the compressor exhaust gas cannot reach equilibrium with users, assumes that the compressor exhaust pressure rating of 8 kg/cm2, but the actual pressure when using only 5 kg/cm2 is even lower, so the load operation of the compressor for a long time, cannot reach the rated pressure value of the machine, which resulted in increased fuel consumption. The reason is that, under the condition of constant displacement, the oil and gas mixture speed up when passing through the oil fraction, and the oil mist concentration is too high, which aggravates the oil fraction load and eventually leads to large oil consumption.

Solution: it is suggested to contact with the manufacturer and exchange a product that can match the low pressure.

8. The return pipe is blocked

When the oil return pipeline (including the one-way valve on the oil return pipeline and the oil return filter) is blocked by foreign matter, the oil condensed at the bottom of the oil separation cannot return to the engine head, and the condensed oil droplets are blown up by the airflow and taken away with the separated air. These foreign bodies are usually caused by solid impurities that fall off during installation.

Solution: stop the machine, remove all the tubing fittings after the pressure of oil drum is released to zero, and blow out the blocked foreign matter. Pay attention to clean the oil and gas barrel cover when installing the built-in oil separation, and pay attention to whether there is any residual solid particles at the bottom of the oil separation core.