Screw vacuum pump load

Dry? Still a water ring type? Claw type?

The original poster is right. It can be seen from the curve as well.

The lower the vacuum level, the lower the power consumption should be; the higher the vacuum level, the greater the amount of gas present, and thus the higher the power consumption.

First, your understanding is incorrect; second, how can you draw any conclusions using the curve of something that is different from a screw vacuum pump? :)

This post was last edited by sdwfsgyykai on 2018-10-5 at 17:38. We can discuss this together… 1. It’s not the case that the higher the vacuum level, the greater the load; generally speaking, the higher the vacuum level, the lower the load. This is because at higher vacuum levels, fewer moles need to be compressed. For the vast majority of vacuum pumps, the power consumption at high vacuum levels comes from compression – the energy consumption can be easily calculated using the adiabatic equation. With fewer moles, less energy is required； 2. A lower vacuum level does not necessarily mean a higher or lower load; this depends on various factors. Generally speaking, for screw vacuum pumps, a measurable parameter is specific power (the same is true for the case mentioned above). Due to the working principle of screw pumps, when operating at low vacuum levels, the volumetric pumping speed of all screw vacuum pumps tends to decrease. Their specific power reaches a maximum value at a certain point and then gradually decreases. But overall, looking at the power curve of screw pumps, there are two situations: one is as you said, the lower the vacuum, the greater the load; the other is that the lower the vacuum, the smaller the load ； The difference between the two is that the former has the lowest power consumption at high vacuum levels (around 0.5–2 kPa·a); however, its volume of gas removed is inversely related to its power consumption – that is, more gas is removed at high vacuum levels, while the amount of gas removed decreases as the vacuum level drops (with power consumption increasing simultaneously due to over-compression) ； In the latter case, the volume evacuation rate remains relatively constant under high and low vacuum conditions, while the power consumption decreases as the inlet pressure increases at a certain pressure level!

This post was last edited by leeGITI on 2018-10-5 at 17:17. Dry screw vacuum pumps are mainly divided into two types of structures: equal-pitch and variable-pitch. Isometric screw vacuum pumps have low power when pumping atmospheric air, and their power reaches its peak at extreme vacuum conditions. For example, our company’s LG70 model has a current of 9.5A when pumping atmospheric air, while this current rises to 12.5A at an extreme vacuum level of 0.5P ； The power consumption varies depending on the degree of vacuum: it is high when pumping air, with high current and power levels; it reaches its lowest value at extreme vacuum conditions. For example, our company’s LGB110 model has a current of 15.6 A when pumping air, while this current drops to 9.8 A at an extreme vacuum pressure of 0.8 Pa.

The load on a dry pump comes from the compressed gas; the less gas there is, the lower the load