Micro vacuum pump, micro air pump selection instructions

July 02, 2023

With the vigorous development of the instrumentation industry, miniature vacuum pumps and micro air pumps that are compact, oil-free and environmentally friendly have become more and more widely used. How can I choose the most appropriate product among the many micro pumps?

The first step is to clarify the purpose of the micropump. We discuss each of them in three major categories.

First, if only the micro air pump is used to output compressed air.

Simply put, it is only used to pump and inflate, and the pump's suction port is basically not used. This situation is relatively simple, according to the output pressure from the largest to the smallest: PCF5015N, FAA8006, FAA6003, FAA4002, FM2002, FM1001. Of course, it is also necessary to refer to relevant technical parameters such as flow indicators.

Second, if the following conditions, you should use WKA series products.

1. Pump or vacuum with a micro pump, but sometimes liquid water enters the pump chamber.

2. The micropump is required to both pump and pump water.

3, mainly pumping water with a micro pump, but do not want to manually add "water diversion" before pumping. (Some pumps need to manually add some “water diversion” before work, so the pump can pump the water from the lower part, otherwise the pump can't pump or even damage.) The strength of the WKA series is that when it is not in contact with water, it pumps Vacuum, after the vacuum is formed, the water is pressed up by the air pressure, and then the water is pumped.

4, pumping with a micro pump, but sometimes the pump may have no water to pump, in a "dry" state. Some traditional pumps are afraid of “dry running” or even fatal. The WKA series is essentially a compound-function pump that integrates the functions of a vacuum pump and a water pump. Some people call it a “vacuum pump”. Therefore, in the absence of water, it will draw a vacuum, and when there is water, it will pump water. Whether it is pumping or pumping, it belongs to the normal working range, so there is no such thing as "dry" damage.

Third, if the pump is pumped with a micro pump, the situation is slightly more complicated.

(1) Judging the working condition of the pumping end of the micro pump

Micropumps for pumping are divided into two categories: gas sampling pumps and micro vacuum pumps. Although they are often simply referred to as micro vacuum pumps indiscriminately, there are differences 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 (ie: the suction resistance of the pump can not be too large), but the price is cheap; in the strict sense, the micro 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 "About the difference between micro vacuum pump and gas sampling pump", no longer repeat.

Gas sampling pumps are: PM series, SA series, SB series; micro vacuum pumps are: VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH series, FM series, FAA series, PCF series, these series All the specifications below are real micro vacuum pumps, such as VM7002, VAA6005, PC3025N and so on.

The magnitude of the suction resistance of the micropump can be measured by the instrument, and it can be compared with the pump's technical parameter "maximum resistance of the inlet port" Por value to know whether the selection is appropriate. Usually, it is determined by simple method based on experience. For example, the following conditions are all large loads (ie, the pump has a large suction end resistance), and can only be selected within the range of the micro vacuum pump:

1 The pump should be connected to a long pipe at the pumping end, or the pipe has many bending points, strong bending or even blocking, or the pipe hole is small (for example, less than φ2 mm);

2 There are throttle valves, solenoid valves, pneumatic switches, filters and other components on the pipeline;

3 pump suction port is connected with the closed container, or the container is not sealed but the intake air amount is small;

4 pump suction port is connected with the suction cup for adsorbing objects (such as integrated blocks, precision workpieces, etc.);

The pumping end of the 5 pump is connected to 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 micro pump exhaust end

All of the above are discussing the problem of the resistance of the pumping end of the micropump. According to these judgment conditions, the range of the selection has been reduced, but the problem of the resistance of the exhaust end must also be considered, so that the optional range can be finally determined.

In practical applications, the micro-vacuum pump faces different exhaust conditions: one is that the exhaust is smooth and straight to the atmosphere; the other is that the exhaust resistance is large, such as valves on the exhaust line, small bends Large damping sensor, non-dedicated silencer, exhaust below the liquid level, gas discharge to a closed or semi-closed container. In modern design and manufacturing, micro vacuum pumps facing different exhaust conditions are treated differently. The parameter “Exhaust port allows maximum resistance Por value” is to calibrate the pump's exhaust capacity, so that we can use strict technical means to determine whether the selection is appropriate.

Simply put, for systems with high 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, VBH series. Based on the above steps, we have been able to determine the selection range of the micropump. In the selected series, we can determine the specific model according to our requirements for flow and vacuum. For products of poor quality, this article is not included in this article, try not to use it. Note that the parameter selection should leave a margin, especially the flow parameters. After the pump is connected to the pneumatic system, the pressure loss will be attenuated due to the pressure loss of the gas circuit components such as pipes and valves. Therefore, the flow rate obtained is less than the nominal flow rate of the pump. Some problems related to the selection are listed below, depending on the usage. consider.

1, with load startup problems.

If the micropump has a vacuum in the pumping port before starting or if there is already pressure in the exhaust port, consider another technical parameter of the pump: the maximum starting load Pis value of the inlet and the maximum starting load Pos value of the exhaust port. A typical application example is to use a micro air pump to maintain the vacuum or positive pressure state inside the container. When the vacuum or positive pressure in the container is lower than the set value, the pump needs to be energized to start, and the machine is stopped when it is higher than the set value. The products that can be started under the ultimate vacuum that can be achieved are: VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH series, VBH series; can start at the maximum output pressure that can be achieved by itself. The products are: FM series, FAA series, PCF series. This performance requires a high level of technical skill from the manufacturer.

2. The medium temperature problem of the micro pump.

Depending on the temperature of the medium gas passing through the pump, whether it is a normal type or a high temperature type is selected.

3. The reliability of the micro pump.

Depending on the severity of the consequences of the micropump failure, it is completely up to your requirements. The average trouble-free continuous running time of quality products is more than 1000 hours, and some are as high as thousands of hours. In particular, this parameter is measured under full load and uninterrupted operation. It is the worst case. If the actual use is not full load or continuous operation, the value will be higher and the height will be higher depending on the working condition of the pump. set. This performance is a test of the manufacturer's technical strength, from the appearance of the product can be seen, such as the use of special motors rather than ordinary low-cost motors, the weight is relatively heavy, and so on. According to the price of the product, you can also know one or two.

4. The electromagnetic interference problem of the micro pump.

If you have a precision circuit-controlled micropump, depending on the circuit's immunity to interference, you may need to order a micropump with low electromagnetic interference.

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