Answers to air filter questions

1、Is the efficiency of the air filter related to the air temperature?

A: The temperature of the oil and water contained in the compressed air has a certain influence on the efficiency of the filter. For example: when the temperature is 30°C, the oil content flowing through the filter is 5 times that of 20°C; when the temperature rises to 40°C, the oil content flowing through the filter is 10 times that of 20°C. Therefore, in summary, the filter should generally be installed at the low-temperature point of the compressed air system, so that the corresponding efficiency will be higher.

2、What are the optional parts of the air filter?

A: Generally, the options include: internal automatic drain, external automatic drain, differential pressure gauge, differential pressure gauge, electronic differential pressure indicator, liquid level indicator, etc.

3、What are the uses of the optional parts of the air filter?

A: The internal automatic drain and external automatic drain are used to automatically discharge the oil, water, and dust mixture filtered out by the filter element to reduce human factors affecting the filtration efficiency of the system. Differential pressure gauges, differential pressure meters, and electronic differential pressure indicators are used to guide the time of filter cartridge replacement. A liquid level indicator is used to indicate the number of mixed pollutants such as oil, water, and dust inside the filter (it can monitor the working condition of the internal automatic drain and guide the manual drainage).

4、Why should the air filter be matched with the purchase to be better?

A: Many people think that it is enough to choose a single filter with the corresponding processing accuracy according to the required air quality, as this can also save costs. But the fact is not so simple, although the air quality needed is determined by the processing accuracy of the single filter selected, without the pre-processing protection of the lower filter, the high precision cartridge will be clogged due to excessive load, thus speeding up the replacement frequency of the cartridge, but in disguise to increase the cost.

5、Can the air filter reduce the dew point of the air?

A: Generally, only solid and liquid particles (droplets) can be removed, while water vapor and oil vapor can pass through the curved passages of the filter material without any obstruction. Therefore, they cannot be removed by mechanical filters (except for activated carbon filters). To fundamentally remove water vapor and oil vapor, the only way is to use a dryer to reduce the dew point temperature of the air.

6、What are the differences between imported and domestic filter elements?

A: Due to the reasons of raw materials and equipment, the domestic cartridge has been lagging behind the imported cartridge in terms of filtration materials and processing technology. The backwardness of testing means and testing equipment makes the domestic cartridge unable to improve its quality due to the absence of quantitative authoritative analysis. Compared with the imported cartridge, the domestic cartridge is more rough and bulky.

7、How to determine the replacement cycle of the air filter cartridge?

A: Generally speaking, the replacement cycle of the cartridge is determined by its pressure drop. When the pressure drop exceeds 0.68kgf/cm2, the pointer of the filter differential pressure meter points to the red area, or the cartridge has worked for 6000-8000 hours (one year), it needs to be replaced. The activated carbon cartridge can be replaced when the smell is measured downstream.

8、Why should the filter cartridge be replaced regularly?

A: Because when the filter cartridge is continuously contaminated, the flow of gas in the system becomes smaller and the pressure drop is correspondingly higher, while the energy and power consumption also increases. The result is a further increase in operating and production costs as well as an increased burden on the environment.

9、What do I need to pay attention to when replacing the cartridge?

A: The following 4 aspects need to be noted: isolate the filter, close the air inlet valve or compressed air supply system, and then close the air outlet valve after completely unloading the pressure (or completely unload the pressure through the filter drain hole after closing the valve concerned); clean the filter housing; unscrew the housing and remove the old cartridge; replace the cartridge with a new one (do not miss the seal, and the cartridge should be installed tightly and correctly).

10、What aspects of air filter installation should be noted?

A: The following 5 aspects should be noted: the working pressure should not exceed the large pressure indicated by the filter; the filter should generally be installed after the after-cooler and storage tank, as close as possible to the point of use and low temperature; the filter should be installed vertically and leave enough space below to replace the filter element; the filter should not be installed after the quick opening valve and prevent backflow and impact phenomenon; larger filters in the pipeline should be Proper support.