Generally, the oil content of the compressed air of the oil-injected screw air compressor is not more than 3ppm (3mg/m3). When the oil content of the compressed air exceeds this standard, we usually call it high oil consumption (commonly known as running oil and flying oil). So how to accurately judge whether the machine is high in fuel consumption? After years of field experience, we can analyze and judge from the following five aspects:

1. For the machine with its own steam trap, take a sample from the drain outlet of the steam trap, drain the water and put it in a clean container to settle for a few minutes, and then observe whether the oil in the form of dots or oil film accumulates on the surface of the container water. Generally, before precipitation, most of the water sampled will be milky white, and there are only a few thin and colorful oil flowers when observed against the light. If there is a lot of oil floating on the water, it means that the fuel consumption is high.

2. Observe the drainage condition of the air tank, and compare with the normal condition before whether the discharged water brings out too much oil. A small amount of oil is a normal phenomenon. If it is more obvious and there is pure oil released, it can also be inferred that the oil consumption of the machine is high. (This method is more general, but sometimes it is slower, and when it is found, the oil may have run more ).

3. Check the amount of residual oil on the inner wall of the pipeline from the minimum pressure valve of the air compressor to the air cooler. After shutdown and deflation, remove the pipe from the minimum pressure valve to the air cooler and touch the inner wall of the pipe with clean hands or paper towels. If there are obvious oil traces, it is inferred that the oil consumption of the air compressor is high, because all the compressed air has to pass through this section of the pipeline, and the compressed air with high oil consumption will leave a relatively high oil content in the pipeline when it passes through.

4. The air outlet of the minimum pressure valve of the air compressor, some models have a pressure sensor or a small thin tube that can directly take out the separated compressed air. The separated compressed air is hit on clean white paper. If there is no oil (smoke), the oil consumption of the machine is not high; if oil (smoke) can be seen, the oil consumption of the machine is high.

5. Check whether the oil level of the machine has dropped significantly. The oil circuit system that needs to be drained out of the machine first has no obvious oil leakage (such as aging oil pipes, oil leakage from the machine head, oil leakage from the cooler, etc. The best way is to open the door of the machine and use a flashlight to look at the bottom of the machine carefully. No flakes of oil remain).

It is best to observe the oil level mirror in the same environment, the same pressure, and the same temperature after the machine is turned on and the loading is stable. For example, when the pressure is 7 kg and the operating temperature is close to 80 degrees, whether the oil level changes greatly before and after. It should be emphasized here that after the machine starts running stably, pay attention to the temperature, pressure, environment and other conditions, otherwise it may lead to inaccurate observation of the oil level and cause misjudgment. A small number of people observe the oil level in the shutdown state, and if they can't see the oil, it means that the machine is running out of oil. This judgment standard is not comprehensive and accurate. Many practitioners know that variable frequency air compressors are more stable. Here we need to subdivide them. This stability means that the air supply pressure is more stable, and the oil level will fluctuate more for variable frequency air compressors.

Through the above five aspects, we can basically conclude whether the machine has a fault with high fuel consumption. In the actual operation and production, the misunderstandings in the judgment of the high fuel consumption of the machine are prone to:

1. The milky white condensed water does not mean that the oil content is high. The milky white color is not oil dissolved in water, but compressed air dissolved in water. You can use a clean mineral water bottle to connect a part of the condensed water to do a small experiment, the precipitation will stand for a while, and the milky white in the condensed water will disappear.

2. When the oil is first installed and started to run, it is inaccurate to see that the oil return volume increases on the oil return pipe oil sight glass of some models. Usually, it takes 4 to 6 hours for the oil to reach saturation, and the judgment of the oil return effect should be based on the oil storage at the bottom of the oil. The less oil at the bottom of the oil, the better.

3. If the oil return pipe is hot, it does not mean that the oil return system is normal. The oil return pipe will also be hot when the gas goes, but the oil return pipe is cold, so it can be basically concluded that the oil return effect of the machine is not good.

4. A small amount of oil traces discharged from the gas storage tank, pipeline, and precision filter cannot be determined to be high fuel consumption. Originally, the oil-injected screw machine has a certain degree of oil content in the air outlet, and it is normal to have a small amount of oil after the compressed air passes through the air storage tank, pipeline, and precision filter for a long time.

5. Once the oil consumption of the machine is high, it is recommended that the after-sales personnel of the nearest dealer go to the scene to check whether there is any oil leakage. Shut down and disassemble the minimum pressure valve to check the oil storage at the bottom of the oil separator to ensure that the oil return system is in good working condition.

6. A small number of users have certain misunderstandings when using the air compressor, that is, the machine is greatly reduced in pressure. It should be emphasized here that it is not recommended for customers to use a large amount of pressure, especially for low-pressure machines. After a large amount of pressure is used, it will inevitably lead to increased fuel consumption.