How to operate Liquid Ring Vacuum Pumps

Today I will tell you how to operate the liquid ring vacuum pump in the vacuum system.

According to the after-sales service feedback report, we have made statistics on the failure analysis of the liquid ring vacuum pump in the last year, and found that very few of them are caused by the quality problems of the liquid ring vacuum pump itself, most of which are caused by the improper operation of the user and the large process defects of the pipeline system.

In particular, when multiple vacuum pumps are used at the same time, attention should be paid to avoid too thin pipeline and too high integration. The pipeline mainly includes the water inlet and drainage as well as the air inlet and exhaust pipeline system. When multiple vacuum pumps are used at the same time, the general user will choose to design the inlet and outlet pipes into one pipe respectively, sometimes the position of the drainage pipe is still high, which seriously affects the drainage efficiency.

Generally speaking, the water supply pipe needs a certain pressure to ensure enough water supply. However, if multiple pump pipes share a main pipe, it is easy to have uneven water supply, which may cause excessive water in the front pump and insufficient water supply in the pump at the end.

Thus some pump vacuum degree is too high, some insufficient phenomenon. Secondly, if the drainage pipeline is relatively thin, a large amount of water enters the pump, the drainage pressure of the drainage pipeline is very large, and the drainage is not timely, which makes the water circulation in the pump not smooth, and the water in the pump is too much. A large amount of water enters the exhaust pipe with the gas. When the pump stops and starts again, the water will flow back into the pump, making the vacuum pump start with full load, frequently and repeatedly, causing great damage to the motor. Secondly, the reduction of the internal space of the vacuum pump results in the reduction of the gas pumping capacity, the high vacuum degree, the reduction of the efficiency and the increase of the motor power.

The integration of the exhaust pipe will generally result in too many elbows and thin exhaust main pipe. When more than one pump is opened at the same time, the pipeline exhaust is not smooth, resulting in excessive pressure in the exhaust pipeline. These are easy to cause system instability, vibration noise and motor overload and so on. There are many bends in the exhaust pipe, and the size of the main exhaust pipe is basically the same as that of each branch pipe. When multiple vacuum pumps work at the same time, it is easy to cause excessive exhaust pressure. Unobstructed exhaust will directly lead to the pressure in the whole system, and unobstructed drainage will lead to excessive water in the pump body and high water pressure. These two aspects cause the following four problems:

1. When the impeller blade is interrupted and the water in the pump is too much, the blade bears more working load, and the blade is prone to plastic deformation or even fracture. Especially in the stiffener and blade root, cracks often appear. Broken blade in the pump body is easy to cause blade and pump body stuck phenomenon.

2. When the mechanical seal is used, it is easy to cause the damage of the mechanical seal, the water flow pressure is too large, and the frequent start-up causes the axial displacement of the loose moving ring of the mechanical seal. The main reason is that the water supply pressure is too large and the drainage pipeline is too thin. Each time, it is started with full water, the water level in the pump is too high, and a large amount of water enters the exhaust pipe with gas. Frequent stop and start-up, the water backflow pump in the exhaust pipe will drive the impeller to rotate in different directions, and the moving ring of the mechanical seal will change greatly due to the impact of water pressure, resulting in the loosening of the moving ring of the mechanical seal, insufficient compression of the moving ring and the static ring, incomplete sealing and water leakage. At this time, the dynamic ring of the mechanical seal cannot squeeze the static ring, and the fixed pin under the static ring cannot fix the static ring of the mechanical seal. With the impact of water, the static ring will rotate in the same direction as the shaft, the pin and the static ring will collide, and the static ring will break, accelerating the damage of the mechanical seal.

3. Over current phenomenon over current phenomenon in the main or start-up operation, the internal water is too much, need to consume a large amount of electrical energy to complete the mechanical movement.

4. The vibration noise of the pump increases the overload operation of the motor, and the operation is uneven. In addition to the continuous rotation of the water in the pump, the vibration of the pump is more severe and the noise is greater than that of the normal. When the vacuum is too high and the water temperature rises, the combination of the two phenomena is easy to produce cavitation. When the vacuum is too high and the pressure in the pump is very small, the water will boil at a lower temperature, and the generated bubbles will explode in the pump. Cavitation will damage the surface roughness and parallelism of the distribution plate in the pump, further aggravate the blade fracture, increase the vibration of the pump and its pipeline, and then affect the service life of the bearing. The unstable operation of the bearing in turn will further damage the mechanical seal, directly affecting the use of the whole equipment.

When the user is in use, if the seal leakage, impeller blade fracture, over current and other phenomena occur repeatedly and cannot be solved well, the system process should be considered. Can contact us in time, we will give you a timely answer, teach you how to operate the liquid ring vacuum pump better method.

How to operate Liquid Ring Vacuum Pumps