In recent years, along with the further requirements of vacuum pump miniaturization and non-polluting working media in various industries, the small-sized, oil-free, maintenance-free, low-noise, DC-powered miniature vacuum pumps have been used more and more widely.
However, due to the large variety of miniature vacuum pumps, they can be classified into: miniature vacuum pumps, micro-pumps, micro-sampling pumps, micro-pumps, micro-pumping dual-use pumps, micro-circulation pumps, etc.; leading customers often confused, in the end how to choose from What is best for your condition?
[General principle of miniature vacuum pump selection]:
Brushless brushless motors can be used to minimize the use of micro-vacuum pumps, brushless vacuum pump parameters can not reach, and then use brush products.
It can be selected from two categories of classification and use of miniature vacuum pumps:
The classification of miniature vacuum pumps
According to the miniature vacuum pump integrated "brush motor" or "brushless motor" to classify.
【Features of Brushed Miniature Vacuum Pumps】
Advantages: Brushed motors with high torque supply power, so the negative pressure, flow rate, etc. can be done higher, the quality, performance, reliability of the brushed products of Kamerer are better, and the overall cost is low In the high-end brushless vacuum pump.
Disadvantages: The life of a brushed miniature vacuum pump is slightly shorter than that of a high-grade imported brushless one.
[Brushless micro vacuum pump features]
Advantages: long life, especially with high-grade imported brushless motor, life is often close to tens of thousands of hours (at full load); especially suitable for continuous operation day and night, such as long-term online sampling pump use ... but also " "Frequency regulation" function, namely the use of "duty cycle" to adjust the speed of the motor (PWM speed regulation), even can achieve constant pressure, constant current, constant speed and other advanced applications.
Disadvantages: Negative pressure and other parameters are smaller than those with brushes; costs are higher than those with brushes.
Therefore, when the parameters can be reached, brushless microvacuum pumps should be selected as far as possible. When the parameters of the brushless products are not enough, brushed products are considered.
The usage of miniature vacuum pump
According to the use of micro-pump selection. We discuss each of the three major categories one by one.
(a) If only the compressed air is output by a miniature air pump.
Simply put, it is used only to inflate and inflate. The pump's suction port is basically not used. Common applications include: explosion under the liquid surface, insufflation into a closed container, etc.; this is relatively simple
(b) If the pump is pumped by a miniature pump, the situation is slightly more complicated:
1. Judging the pumping conditions of the micro pump
Micro air pumps for pumping are divided into two categories: gas sampling pumps and miniature vacuum pumps.
In short, the difference between the two is as follows: The gas sampling pump can only have a small load (ie: the pump suction resistance can not be too large), but the price is cheap; strictly speaking, a miniature vacuum pump can bring a large load (exhaustion side allows Big resistance, or even complete blockage, but the price is slightly more expensive.
Aspirating dual-use categories include:
The size of the resistance of the suction side of the micro-pump can usually be determined based on experience. For example, the following situations are all due to the fact that the load is relatively large (ie, the suction resistance of the pump is large) and can only be used in the “mini vacuum pump”. Range selection:
1.Long piping should be connected to the pumping end of the pump, or the piping should be bent at a large number of points, or the bending of the pipe should be severe, or it should block the seal, or the hole in the pipe should be small (for example, less than φ2 mm);
2.There are throttles, solenoid valves, air circuit switches, filters and other components on the pipeline;
3.The pump air inlet is connected with the airtight container, or the airtight container is not sealed, but the air intake volume is small;
4.pump suction port and sucker connection for adsorption of objects (integrated block, etc.);
5.The suction side of the pump is connected to the filter container for accelerating the filtration of the liquid.
(c) Judging the Micro Pump Exhaust Condition
In addition to considering the suction side, the exhaust resistance must also be considered in order to finally determine the available range. In practical applications, the exhaust conditions faced by the micro-vacuum pumps are different: one is that the exhaust gas is very smooth and passes through the atmosphere, and the other is that the exhaust gas resistance is relatively large, such as valves and elbows on the exhaust line. Sensors, under-surface venting, and gas venting to sealed or semi-sealed containers require different treatment.
Based on the above steps, we have been able to determine the range of micro-pump selection. According to the requirements of the flow rate and vacuum degree, the specific model can be determined. Pay attention to the choice of parameters to leave a margin, especially the flow parameters.
There are some issues related to selection and are listed below, based on usage considerations.
1. with the load start problem.
2. the micro-pump medium temperature problem.
3. the reliability of micro-pumps.
4. Electromagnetic interference problem of micropumps.
The best solution is to choose a micro-brushless vacuum pump; because it basically does not interfere.