How to Choose A Vacuum Pumps?
How to choose a vacuum pumps for laboratory vacuum filtration use?
First of all, we must understand the use of the vacuum pump, whether the extracted gas is corrosive. To filter the general sample, we can choose an oil-free vacuum pump. If the reagent is purified, you need to choose a corrosion-resistant vacuum pump.
Secondly, it is considered from the aspects of the equipment and equipment configured with the vacuum pump. If it is used to configure the rotary evaporator, it is necessary to use a corrosion-resistant vacuum pump, because the gas volatilized by the rotary evaporation is corrosive; if it is used for the drying oven, the vacuum pump with a relatively high vacuum can be selected. For example, the oil pump in a non-dry vacuum pump.
Most of the vacuum in the laboratory is concentrated above 2 m bar. In a low vacuum environment, the pumping time satisfies the following relationship.
P1 – initial pressure (atmospheric pressure) [Pa];
P2 – arrival pressure [Pa];
T – pumping time [min];
V – volume [L];
Se – actual pumping speed [L/min].
Considering the pipeline and valve effects, the actual pumping speed is 80% of the theoretical pumping speed.
Hawach vacuum pumps are divided into two series:
1. Standard Diaphragm Vacuum Pumps, ideal for clean and efficient vacuum pumps, unique piston cavity design for long-term operation. Commonly used in: laboratory vacuum filtration, vacuum suction, vacuum drying ovens, etc.
2. Anti-Corrosion Diaphragm Vacuum Pumps, the entire gas path is not in contact with the metal part of the pump body, and the PTFE membrane covers the metal part. Diaphragm pumps can be used for vacuuming with corrosive gases such as rotary evaporators, reagent purification, reactors, etc.