Under the need of modern industrial development, we usually choose vacuum pump unit when it is used to adsorb large objects. In practice, this kind of behavior is to suck the object after vacuumizing the suction cup with the pump. Therefore, it is necessary to select the vacuum pump in the true sense. The gas sampling pump cannot be selected. Theoretically, the adsorption force of vacuum pump unit can be calculated according to the suction required by the object. The general process is shown in the following points.
Because it is impossible to seal the gas system theoretically, there is always some leakage. In this case, the greater the flow rate of the vacuum pump unit, the smaller the proportion of leakage, the more conducive to maintain a higher vacuum degree of the pump, so as to obtain greater adsorption force.
For example, if there are two pumps with the same limit vacuum degree, the flow rate of vacuum pump is 1L / min, and the flow rate of vacuum pump is 20L / min. under the same leakage condition of 0.1l/min, the vacuum degree of vacuum pump will be greatly reduced, because the leakage of 0.1l/min is too large for it. However, the leakage of 0.1l/min is nothing to the vacuum pump, which can still maintain a high vacuum degree. Therefore, although the vacuum degree of the two is the same, in practice, the adsorption force produced by the pump is greater. Therefore, it is necessary to consider both the vacuum degree and the flow rate when selecting the vacuum pump unit.
When the need to release the sucked objects, the vacuum pump unit must be shut down first, do not continue to vacuum. After the pump stops, the object may not be immediately scattered, because the pump has a certain ability to maintain pressure, the vacuum will continue to maintain for a while. In order to release the gas system immediately, an additional branch circuit should be added to connect an on-off valve. The pump should be shut down and the valve should be opened at the same time, so as to eliminate the vacuum in the gas system immediately, so as to release the object reliably.