Water ring vacuum pump working principle

First, use and scope of use
SK series water ring vacuum pumps and compressors are used to pump or press gas and other non-corrosive, water-insoluble, solid particles-free gases to create a vacuum or pressure in a closed container to meet specific process flows. Required equipment. A small amount of liquid is allowed in the gas to be inhaled or pumped.
SK series water ring vacuum pumps and compressors are widely used in machinery, petroleum, chemical, pharmaceutical, food, ceramics, sugar, printing and dyeing, metallurgy, environmental protection and electronics industries.
Since the compression of the gas in the pump is performed under isothermal conditions during the working process, it is less prone to danger when the flammable or explosive gas is pumped or sucked, so its application is more extensive.
Pump model description. Example: SK-122i2J
SK is represented as a water ring vacuum pump; 12 indicates that the pump has a large pumping capacity of 12 m3/min (m3/min)
Second, the working principle
The impeller 3 is eccentrically mounted in the pump body 2. When starting, a certain height of water is injected into the pump as a working fluid. When the impeller 3 rotates in the direction shown, the water is subjected to centrifugal force to form a rotating closed water on the inner wall of the pump body. Ring 5, the upper inner surface of the water ring is tangent to the hub, and the lower inner surface of the water ring is just in contact with the tip of the blade. At this time, a crescent-shaped space is formed between the impeller hub and the water ring, and this space is divided by the impeller into a plurality of small cavities equal to the number of blades. If the upper part of the impeller is 0° as the starting point, then the volume of the small cavity becomes smaller from 180° before the rotation, and the air pressure in the space is reduced, and the gas pressure in the space is lowered. Inhalation, when the inhalation is finished, the small cavity is isolated from the suction port; when the impeller rotates between 180° and 360°, the inner surface of the water ring gradually approaches the hub, and the small cavity becomes larger and smaller, and the gas in the space When the pressure rises above the exhaust port pressure, the gas is expelled when the small chamber communicates with the exhaust port.
Every revolution of the impeller, the space between the blades (small cavity) is sucked and exhausted once, and several small cavities work continuously. When so, the pump continuously sucks or presses the gas. Since the work generates heat during work, the working water ring will heat up, and at the same time some of the water and gas are discharged together. Therefore, during the work, the pump must be continuously supplied with water to cool and replenish the water consumed in the pump. To meet the working requirements of the pump.
When the gas discharged from the pump is no longer used, a steam separator is connected to one end of the pump exhaust port (a water tank can be made by itself), and the exhaust gas and part of the water are discharged into the steam separator, and the gas is discharged from the exhaust pipe. The water remains in the separator due to gravity and is supplied to the pump for circulation through the return pipe. With the length of working hours, the temperature of the working fluid will continue to rise. At this time, a certain amount of cold water (using tap water) should be added to the steam separator to reduce the temperature of the working fluid and ensure that the pump can reach the required technology. Requirements and performance indicators When used as a compressor, the pump exhaust port is connected to the car separator. The car mixture is automatically separated after entering the steam separator. The gas is delivered from the exhaust pipe to the required system and the working fluid is discharged through the automatic overflow switch. When the gas is compressed, the working fluid is very prone to heat. When it is discharged from the pump outlet, the temperature will become higher. Therefore, at the bottom of the steam separator, cold water should be continuously supplied to replenish the hot water that is released and at the same time cool. So that the temperature of the working fluid is not too high, so as to ensure the performance of the compressor, meet the technical specifications, and meet the requirements of the work.
Third, the structure description
The pump consists of the pump body, front and rear end caps, impeller, shaft and other parts. The intake pipe and the exhaust pipe are connected to the pump chamber through an air suction hole and a vent hole installed on the disc on the end cover, and the impeller is fixed to the shaft by a key, and is eccentrically installed in the pump body. The total clearance at both ends of the pump is adjusted by the pad between the pump body and the disc. The gap between the impeller and the front and rear discs is adjusted by the bushing (SK-1.5/3/6) to push the impeller. Evenly. For SK-12 and above pumps, the shaft and the impeller are interference fit, and this clearance is determined by the front end positioning. The SK-120 has no bushings and the rest of the structure is identical to SK-6/12/30/42/60/85. The gap between the end faces of the impeller and the front and rear discs determines the amount of gas lost in the flow from the inlet to the exhaust port in the pump chamber and its ultimate pressure.
The packing is installed in the two end covers, and the sealing water enters the packing through the small holes in the end cover to cool the packing and enhance the sealing effect. The supplementary water required for the impeller to form a water ring is supplied by the water supply pipe (tap water), and the water supply pipe can also be connected with the steam separator to circulate water.
If the seal form uses a mechanical seal, the mechanical seal is installed in the packing cavity, no filler is required, and the packing gland is replaced with a mechanical seal gland, and the rest of the structure is the same.
The bearing is fixed to the shaft by a nut. A disc is mounted on the end cap, and the disc is provided with suction, exhaust holes and rubber ball valves. The function of the rubber ball valve is to discharge the gas before the exhaust port when the gas pressure between the impeller blades reaches the exhaust pressure, to feed the power consumed due to the excessive gas pressure, and to reduce the power consumption.
Fourth, the equipment description
The series of water ring vacuum pumps and compressor systems consist of a vacuum pump (compressor), a coupling, an electric motor, a steam separator and a pipeline.
The working process of the vacuum pump and the compressor and the steam moisture main device is as follows: the gas enters the vacuum pump or the compressor through the pipeline through the valve, and then is discharged into the steam separator through the air guiding elbow, and is discharged through the exhaust pipe of the steam separator. When used as a compressor, after the steam-water mixture discharged from the compressor is separated in the steam-water separator, the gas is sent through the valve to the system requiring the compressed gas, and the water is left in the steam-water separator, and the water level in the steam-water separator passes. The automatic overflow switch is adjusted. When the water level is higher than the required water level, the overflow switch is opened and the water overflows from the overflow pipe; when the water level is lower than the required water level, the overflow switch is closed, and the water level in the steam separator rises to reach the required water level. The working fluid in the vacuum pump or compressor is supplied by a steam-water separator (also available with tap water), and the amount of water supplied is adjusted by the valve on the water supply pipe.
The difference between the gas suction and the pressure delivery system is only that the internal structure of the steam separator is different. When pumping gas, the suction port pressure is lower than atmospheric pressure, and the exhaust port pressure is equal to atmospheric pressure, the steam-water separator only has overflow pipe; when the gas is supplied, the suction port is normal pressure (also can be vacuum state), the exhaust port The pressure is higher than one atmosphere. To ensure the pressure of the delivery gas, the water level of the separator is controlled by the overflow switch.