Enter compressed air
1. If you only use a micro air pump to output compressed air.
To put it simply, it is only used for pumping and inflating, and the suction port of the pump is basically not used. This situation is relatively simple. You can choose from highest to lowest output pressure: PCF5015N, FAA8006, FAA6003, FAA4002, FM2002, FM1001. Of course, reference should be made to related technical parameters such as flow indicators.
2. If the air is pumped by a micro pump, the situation is slightly more complicated.
(1), determine the working condition of the suction side of the micro pump
There are two types of micro pumps for pumping gas: gas sampling pumps and micro vacuum pumps. Although they are usually simply referred to as miniature vacuum pumps without distinction, they are different from a technical point of view, and special attention should be paid to the selection.
In short, the gas sampling pump can only carry a small load (that is, the resistance at the suction end of the pump cannot be too large), but the price is cheap; in a strict sense, the miniature vacuum pump can carry a large load (the suction end allows large resistance, or even complete Blocked), but the price is slightly more expensive. The specific differences between the two can be found in the article "On the difference between micro vacuum pumps and gas sampling pumps", which will not be repeated.
Gas sampling pumps are: PM series (specific models such as: PM950.2, PM850.5, PM8001, PM7002, PM6503); miniature vacuum pumps are: VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH Series, PH series, FM series, FAA series, PCF series, all specifications under these series are real miniature vacuum pumps, such as VM7002, VAA6005, PC3025, etc.
The resistance of the suction end of the micropump can be measured with an instrument. Compare it with the Por value of the technical parameter of the pump "Maximum Allowable Resistance at the Air Inlet" to know whether the selection is appropriate. It is usually determined by a simple method based on experience. For example, the following situations are due to the large load (that is, the resistance of the pumping end of the pump is larger), and can only be selected within the range of the micro vacuum pump: ① Connect a very long pipeline, or the pipeline has many bending points, severe bends, or even blocked or closed, or the inner hole of the pipeline is small (for example, less than φ2 mm); ②There are throttle valves, solenoid valves, gas switches, and filters in the pipeline And other components; ③the pump suction port is connected with a closed container, or although the container is not sealed but the air intake is small; ④the pump suction port is connected with a suction cup for adsorbing objects (such as integrated blocks, precision workpieces, etc.); ⑤pump The suction end is connected to the filter container, and a filter screen is placed at the mouth of the container to accelerate liquid filtration.
(two), determine the working condition of the exhaust end of the micro pump
The above are all discussing the resistance of the suction end of the micropump. According to these judgment conditions, the selection range has been narrowed, but the resistance of the exhaust end must also be considered, so that the selection range can be finally determined.
In practical applications, the exhaust conditions faced by miniature vacuum pumps are different: one type is very smooth and direct to the atmosphere; the other type is the exhaust resistance is large, such as a valve and a small elbow in the exhaust pipe , Large damping sensor, non-dedicated muffler, exhaust below the liquid level, gas exhaust to a closed or semi-closed container, etc. In modern design and manufacturing, miniature vacuum pumps facing different exhaust conditions are treated differently. The parameter "Por value of the maximum allowable resistance of the exhaust port" is to calibrate the exhaust capacity of the pump, so that we can use strict technical means to determine whether the selection is appropriate.
Simply put, for systems with large exhaust resistance, our selection range is: FM series, FAA series, PCF series; for systems with low exhaust resistance, the selection range is: VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH series, PH series. According to the above steps, we can already determine the selection range of the micro pump. Among the several optional series delineated, the specific model can be determined according to our requirements for flow and vacuum. For products of poor quality that are not included in this article, try not to use them. Pay attention to the parameter selection to leave a margin, especially the flow parameter. After the pump is connected to the gas circuit system, due to the pressure loss caused by the gas circuit components such as pipes and valves, the flow will be attenuated, so the obtained flow is less than the nominal flow of the pump