Roots - water ring vacuum pump unit introduction

Roots pump-water ring vacuum pump unit is widely used in chemical, food sublimation drying, high-altitude simulation test and other vacuum systems, it can remove a large number of condensable steam, especially when the gas town oil seal mechanical vacuum pump to remove condensable steam capacity is not enough, or the use of solvents can make the pump oil deterioration and affect the performance, or the vacuum system does not allow oil pollution when more obvious.

Operation of Roots pump - water ring pump unit:

(1) Front condenser of the unit

In order to make the volume of the unit as small as possible, the steam to be pumped can be condensed before entering the pump unit, so that the remaining is non-condensable gas and trace residual steam. The volume of the gas decreases under the same pressure after cooling. Therefore, the required pumping volume is reduced after condensation, and the pump can be selected smaller accordingly.

Because only non-condensable gas is left after the water steam is cooled, the specific volume of the water steam is quite large when the pressure is very low, and the amount of pumping required by the pump is obviously greatly reduced after the condensation of these condensable steam. In addition, regardless of whether the steam condenses, as long as the gas temperature is reduced under the same pressure, its volume flow will be reduced. For example, gas with a temperature of 200~300 ° C in chemical processes is not uncommon. After cooling from 300 ° C to 50 ° C, the volume of dry air is reduced by about 45%, so that a smaller capacity suction vacuum pump unit can be selected.

(2) Operation sequence of the unit:

1) When there is no bypass valve in the unit, the water ring pump should be started first, and the gas in the pumped system is pumped by the Roots pump (the gas drives the Roots pump rotor to rotate itself, like a flow meter) into the water ring pump and then discharged to the atmosphere, when the suction pressure of the water ring pump (if there is a large air pump in series, it is the suction pressure of the large air pump) reaches the initial specified value of the Roots pump (that is, the allowed exhaust pressure), Start Roots pump, the unit officially operated, began to work.

2) When there is a bypass valve in the unit, start the water ring pump first, and then start the Roots pump. At this time, the inlet and exhaust pressure difference of the Roots pump is large, and the bypass valve is automatically opened. Part of the gas in the pumped container enters the water ring pump through the bypass valve, and the other part enters the water ring pump through the pump under the action of the Roots pump, obviously the pumping rate increases, so that the pre-vacuum of the Roots pump is quickly achieved. The inlet and exhaust pressure difference is small, the valve is automatically closed (or manually closed), and the unit is officially working. This method can greatly shorten the pre-drawing time, but the equipment is more complicated.