Vacuum suction cups are a common application of vacuum pumps, used in vacuum processing and CNC machining centers. The main principle is to create a vacuum at the suction cup using a vacuum pump and allow for the pressure difference to absorb various workpieces. So how do we know how much adsorption the vacuum cleaner will produce in the vacuum pump's suction application?
The estimation of the adsorption force is mainly based on the pressure formula, that is, F=PS. In the application of vacuum suction, the calculation method is slightly adjusted as follows: F≈(101≤P absolute pressure)xS suction cup area x10≤.
In the formula, F is the theoretical adsorption force produced by the vacuum suction cup, with a unit of absolute pressure (KGF) in tons; P (in units of (KPa)) is the absolute vacuum degree achieved in the vacuum pump application; 101 is the standard atmospheric pressure, so adjustments may need to be made depending on the altitude in certain special areas; S suction cup area: the effective area of the vacuum suction cup, in square centimeters.
For example, with a vacuum pump, the vacuum degree can reach 10 kPa, and the pressure difference between it and atmospheric pressure is 101~10=91 kPa. At this time, the effective area of the vacuum suction cup is 10 square centimeters, and the adsorption force is 91x 10x0.01, which theoretically can reach 9.1 Kgf.
Equally important is that this estimation method ignores the influence of the vacuum pump flow on the vacuum maintenance force and adsorption force. In practical applications, the adsorption force of the vacuum suction cup is still related to its flow rate.
As rough and low vacuum gas circuit systems cannot be completely sealed, leaks always exist. In this case, the larger the flow rate of the vacuum pump, the smaller the proportion of leaks, the more conducive it is to maintaining the vacuum of the adsorption system and obtaining a larger adsorption force.
At the same time, a higher flow rate can also achieve a faster vacuum suction reaction time.
For example, for two pumps with the same ultimate vacuum degree, type A vacuum pump has a flow rate of 1 L/min while type B vacuum pump has a flow rate of 20 L/min. First, the two vacuum pumps have a big difference in pumping speed, so the time to reach the predetermined vacuum degree is different.
At the same time, with a leak rate of 0.1 L/min, because the leak rate of 0.1 L/min is too large, the vacuum degree of type A vacuum pump is much lower. But for type B vacuum pump, the same leak rate is meaningless, and it can still maintain a high vacuum degree. Therefore, although both have the same final vacuum degree, in practical applications, the larger flow rate vacuum pump has a stronger and faster adsorption force.