Miniature air pump, electromagnetic valve

The selection of micro vacuum pump and micro air pump shows that with the vigorous development of instrument industry, micro vacuum pump and micro air pump with small volume, no oil and environmental protection are more and more widely used. How to choose the most suitable product among all kinds of micropumps? First of all, we should make clear the purpose of micropump. We discuss them in three categories. First, if only a micro air pump is used to output compressed air. Simply put, it is only used for inflating and inflating, and the air inlet of the pump is basically not used. This situation is relatively simple, and the output pressure can be selected in descending order: PCF50 15N, FAA8006, FAA6003, FAA4002, FM2002, FM 100 1+0. Of course, we should also refer to relevant technical parameters such as flow indicators. Second, you should choose WKA series products if. 1. Use a micro pump to pump air or vacuum, but sometimes liquid water will enter the pump cavity. 2. Micropumps need to pump air and water. We mainly use micropumps to pump water, but we don't want to rely on manual "water diversion" before pumping water. (Some pumps need to manually add some "water diversion" before working, so that the pump can pump up the water at the lower part, otherwise the pump will not pump water or even be damaged. The advantage of WKA series products is that when it is not in contact with water, vacuum is pumped, and after vacuum is formed, the water pressure is increased by air pressure, and then water is pumped. 4. Pump water with a micro-pump, but sometimes the pump may have no water to pump and be in a "dry operation" state. Some traditional water pumps are afraid of "dry running" and even fatal. WKA series products are essentially a kind of compound function pump, which integrates the functions of vacuum pump and water pump. Some people call it "vacuum pump". Therefore, in the absence of water, when there is water, vacuum will be pumped. Both the pumping state and the pumping state belong to the normal working category, and there is no "dry rotation" damage. Third, if the pump is used, the situation is a little more complicated. (1) Judge the working state of the pumping end of the micropump. Micro-pumps for pumping air are divided into two categories: gas sampling pumps and micro-vacuum pumps. Although they are always simply called micro vacuum pumps indiscriminately, they are different from each other from a technical point of view, so special attention should be paid when choosing them. 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 it is cheap; Strictly speaking, the micro vacuum pump can carry a large load (the suction end allows a large resistance, or even a complete blockage), but the price is slightly expensive. The specific difference between the two can be found in the article "Difference between Micro Vacuum Pump and Gas Sampling Pump", which is not repeated here. Gas sampling pumps are: PM series, SA series and SB series; Micro vacuum pumps include: VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH series, FM series, FAA series and PCF series. All specifications under these series are real micro vacuum pumps, such as VM7002, VAA6005, PC3025N, etc. The resistance at the suction end of the micropump can be measured by instruments. By comparing with the technical parameter Por value of the pump, we can know whether the selection is appropriate. It is usually determined by a simple method based on experience. For example, the following situations are all heavy loads (that is, the resistance at the suction end of the pump is large) and can only be selected within the scope of the micro vacuum pump: ① The suction end of the pump is connected with a long pipeline, or the pipeline has many bending points, which may even be blocked and closed, or the inner hole of the pipeline is very small (for example, less than φ 2mm); ② Throttle valve, solenoid valve, gas path switch, filter and other components are arranged on the pipeline; ③ The suction port of the pump is connected with a closed container, or the container is not closed but the air intake is small; (4) The suction port of the pump is connected with the sucker for adsorbing objects (such as integrated blocks and precision workpieces); ⑤ The suction end of the pump is connected with the filter container, and a filter screen is placed at the container mouth to accelerate the liquid filtration. (2) Judging the working condition of the exhaust end of the micropump is all about discussing the resistance of the exhaust end of the micropump. According to these judgment conditions, the selection range is narrowed, but the resistance at the exhaust end must also be considered before the optional range can be finally determined. In practical application, the exhaust situation of micro vacuum pump is different: one is that the exhaust is smooth and straight to the atmosphere; The other is high exhaust resistance, such as valves, small elbows, large damping sensors, non-dedicated silencers, exhaust below the liquid surface, and gas discharged into closed or semi-closed containers. In modern design and manufacture, micro vacuum pumps facing different exhaust conditions are treated differently. The parameter "Por value of allowable maximum resistance of 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. To put it simply, for systems with high exhaust resistance, our selection ranges are: FM series, FAA series and PCF series; For systems with low exhaust resistance, the selection ranges are: VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH series and VBH series. According to the above steps, we can already determine the selection range of micro-pump. In several optional series, the specific model can be determined according to our requirements for flow and vacuum. Products with poor quality are not included in this article, so try not to choose them. Pay attention to the parameter selection to leave margin, especially the flow parameter. After the pump is connected to the gas circuit system, the gas circuit components such as pipelines and valves will cause pressure loss and flow attenuation, so the obtained flow is less than the nominal flow of the pump. Here are some problems related to selection, which should be considered according to the use situation. 1. Start with the load. if