Slide valve vacuum pumpWidely used in industries such as aerospace, aviation, atomic, petroleum, chemical, pharmaceutical, electrical, ceramics, smelting, new materials, vacuum heat treatment, vacuum coating, etc.
Slide valve vacuum pumpKey application points:
Although the slide valve pump is an old pump, compared with rotary vane pumps, it has outstanding advantages such as allowing high working pressure (104Pa), large pumping capacity, continuous operation in harsh environments, and durability. Therefore, it has been widely used in industries such as vacuum smelting, vacuum drying, vacuum impregnation, and vacuum distillation.
With the increasing application range of vacuum, slide valve pumps used in industries such as vacuum drying, vacuum impregnation, vacuum dehydration, and vacuum smelting contain a large amount of water vapor for gas extraction.
If it cannot be eliminated in time in the vacuum pump, it will contaminate the vacuum pump oil and cause a decrease in the pumping performance of the vacuum pump.
Although a gas ballast valve is installed on the pump to reduce the maximum vacuum of the pump and remove condensable gases using the gas ballast method, it is not ideal for vacuum drying, dehydration, and sludge refining processes with high water vapor content. Generally, the following methods can be tried:
a. The slide valve pump is used in conjunction with the condenser.
Currently, most domestic manufacturers adopt this solution.
The principle is to connect the condenser in series between the pump and the container being pumped, capturing a large amount of water vapor in the vacuum process equipment into water using the condenser, thereby reducing the amount of water vapor entering the vacuum pump and reducing the degree of pump oil pollution.
If the flow rate of the condenser outlet valve is appropriately adjusted and the air damper on the vacuum pump is fully utilized, a good pumping effect can be achieved.
b. Transform the slide valve pump into a heat pump.
According to the physical properties of water and the principle of phase diagram, the slide valve vacuum pump can be replaced with a heat pump. In this way, a large amount of condensable water vapor can be extracted under higher pump chamber temperature conditions.
The working principle is as follows: using an automatic temperature control controller, the cooling water flow of the pump is automatically controlled to achieve the purpose of controlling the temperature of the pump chamber.
During the pumping process, the temperature of the pump chamber is always controlled above the saturation vapor pressure temperature of water, which promotes the smooth discharge of a large amount of water vapor in the pumped gas.
To avoid phenomena such as thinning of pump oil, decrease in vacuum degree, and jamming of operating components that may occur due to high temperature inside the pump chamber during long-term operation, high-temperature resistant pump oil such as (N-62 or N-68) and high-temperature resistant bearings can be used in the design Increase the clearance between operating components, etc.