Water temperature, water inflow and water pressure influence the pumping amount of water ring vacuum pump
发布时间：2018-10-10 17:10:41
According to Dalton's law of gas, the pressure of mixed gas is equal to the sum of the partial pressures of various components of the gas. Therefore, the saturated vapor pressure of water has an inevitable influence on the pumping volume of the pump, especially when the water temperature is higher and the suction pressure is lower (the vacuum degree is higher), and the influence on the gas volume is more significant.
Due to the technical documents on the volume values are under the condition of the pump inlet water temperature of 15 ℃ at home and abroad, therefore the actual water temperature should be consider when choosing pump.
The influence of water temperature on gas volume can be illustrated by an example. According to the standard GB/T 13929 "test methods for water-ring vacuum pumps and water-ring compressors", the influence coefficient K1 of water temperature on the amount of air pumped by water-ring vacuum pumps can be calculated as follows.
K1=(p1-p15)/(p1-pt)
P1 -- -pump inlet gas pressure (absolute pressure), hPa;
P15 - when the water temperature of 15 ℃ saturated vapor pressure of 17.04 hPa;
Pt - when the water temperature of t ℃ saturated vapor pressure of hPa.
If water temperature 30 ℃, the saturated vapor pressure of 42.42 hPa, when the inlet gas pressure 400 hPa, the temperature influence coefficient K1 = 1.07, that is due to the influence of the saturated vapor pressure of water swept volume compared with water temperature 15 ℃ was reduced by 7%, if the inlet pressure is lower and the water temperature is higher, the impact on the volume is bigger. Therefore, it is necessary to minimize the water temperature of the pump in the application.
The amount of water intake also has a certain impact on the amount of gas. It's too much water, it's not obvious to increase the amount of gas, but it increases the shaft power of the pump. The water inflow is too small, the sealing effect of the gap is reduced, the air quantity is reduced and the water temperature is increased too fast. A suitable amount of intake water is considered by the pump house to be one of the conditions necessary for proper operation of the pump. So far, all the technical specifications for the factories have been given the amount of water in the pump, which is usually done by experiments, but it is required to supply the water supply in the manual.
The water supply pressure is generally between 0.06 MPa·G and 0.10 MPa·G. Water temperature can also determine whether the water supply is appropriate. In general, the temperature difference between outlet and inlet is 5～10 ℃, if over 15℃，it indicates that the water supply is relatively small, and the water supply should be increased.
