To understand the water ring roots vacuum unit of several proportions
Release date:2016-08-15 Author: Click:
Roots water ring vacuum unit under ordinary conditions, water ring pump chosen as the backing pump more advantageous than other vacuum pump, this is mainly because it can draw in addition to a large number of condensable vapor, especially when the gas ballast mechanical vacuum pump oil seal steam sweep condensable sex ability is not enough, or the use of solvent can make pump oil deterioration and impact performance, or the vacuum system does not allow oil pollution was more obvious.
Roots pump - water ring pump unit is widely used in chemical industry, food sublimation boring, high altitude simulation experiments and other vacuum systems. This kind of combined unit has the following types.
> roots pump - water ring pump unit
The role of the water ring pump in the unit is to form the preparatory vacuum required for the roots pump, so the maximum allowable exhaust pressure of the water ring pump is requested, that is, the maximum allowable exhaust pressure of the water ring pump should be improved as far as possible on one hand, and on the other hand, the maximum allowable exhaust pressure of the roots pump should be improved.
Ordinary condition, single stage water ring pump ultimate vacuum is not high, but at present, China's consumption of roots pump forevacuum and higher request, so the practice on the single stage water ring pump as backing pump of roots pump, and can you improve the limit of two stage water ring vacuum pump as the backing pump is applied, using two stage water ring pump, will also be able to progress the ultimate vacuum unit.
The ultimate vacuum degree of a roots pump is low, especially when it is combined with a water ring pump, the application range is limited, and the ultimate vacuum degree of the whole unit may be lower. However, if two roots pumps are used in tandem with the water ring pump, the ultimate vacuum degree of the unit can be greatly improved.
> roots pump - water ring pump - gas pump unit
Even with a two-stage water ring pump, the improvement in the ultimate vacuum is only within a certain range due to the limitation of the saturated vapor pressure of water. The theoretical limit pressure of water ring pump is the saturated vapor pressure of water. If the influence of gas reflux and other factors is considered, the ultimate pressure of the water ring pump in practice is significantly higher than that of the saturated steam pressure in the water temperature. In order to improve the limit vacuum of the front stage pump, the combination of water ring pump and large air pump can also be used.
> roots pump - water ring pump parallel mechanical vacuum pump
This unit is mainly used for the disposal of large amount of water vapor, and the maximum vacuum degree requires a high vacuum system, such as vacuum boring.
In a vacuum system with a large amount of water vapor to be disposed of, it is more appropriate to use water ring pump, but due to its low limit vacuum degree, the limit vacuum degree of the whole unit is lower. It is true that the mechanical vacuum pump with high demand limit vacuum is used as the pre-stage pump in the vacuum system with high demand vacuum degree. However, due to the high power consumption, low efficiency and high noise of water ring pump, it is not economical to use water ring pump as the pre-stage pump of roots pump in a boring vacuum system with a long demand.
Under the above conditions, the pneumatic mechanical vacuum pump can be connected in parallel with the water ring pump as the front stage pump of the roots pump. When the vacuum is dry, the water ring pump should stop pre-pumping until the water vapor is greatly reduced, and then start the pneumatic mechanical vacuum pump and cut off the water ring pump. If a dry place takes longer to complete, less cooling water and power are required.