With the rapid development of vacuum pump technology, the original vacuum equipment and vacuum process system can not meet the new requirements of energy saving, high efficiency and environmental protection, especially the recovery of process solvent.

 

Compared with water ring vacuum pump

1. The ultimate vacuum is 3300Pa, and the vacuum degree of oil-free vacuum pump is higher, reaching 1Pa. Many water-ring Roots units can be replaced by only one screw vacuum pump.

2. Water as a sealing material, there is a certain consumption. In most parts of north China, the content of calcium and magnesium ions in tap water (usually in the situation of calcium bicarbonate/magnesium and calcium carbonate/magnesium, commonly known as temporary hardness and permanent hardness) is relatively high, and vacuum pump is easy to form scale. Dry screw vacuum pump does not need water to form vacuum.

In order to solve the problem of temperature rise, it is necessary to install a refrigerating unit in the system to cool the circulating water, which firstly increases the equipment cost and power consumption. The vacuum degree of dry screw vacuum pump is stable and not affected by external conditions.

 

Compared with oil mechanical pump (rotary vane pump, slide valve pump)

1. The ultimate vacuum of rotary vane and slide valve pump is high, which can reach 0.1Pa in general. If the process requires high limit vacuum, dry screw vacuum pump can be used in series to achieve this vacuum.

2. Oil mechanical pump cannot pump the medium containing large water vapor and corrosive, otherwise the oil is easy to emulsify and deteriorate, affecting the vacuum and life.

3. Oil mechanical pump can not pump dust containing medium, otherwise it will cause pump wear. Because the mechanical pump belongs to frictional operation, timely suction clean gas medium, after many years of operation, with the increase of clearance in all aspects, the limit vacuum will be reduced.

4. The noise of oil pump, emission of lampblack and consumption of vacuum oil increasingly fail to meet the requirements of environmental protection and energy saving.