The most commonly used vacuum pump - papermaking industry

water ring vacuum pump is one of the most commonly used vacuum pump papermaking industry. At present, most of the completed paper machine project still USES the standards of water ring vacuum pump as vacuum system.

:

the present invention has simple structure, low manufacturing accuracy, easy to processing.

compact structure, high water pump speed. In general, it can be directly connected to the motor, without gear reducer. Therefore, the use of the structure of the small size, can get large exhaust volume, and occupied area is small.

basically compressed gas is isothermal, namely compressed gas process temperature change is very small.

no metal friction surface due to the pump cavity, so do not need lubrication inside the pump, the wear is very small. Seal between rotating parts and fixed parts can be done directly through the water seal.

suction uniform, stable and reliable running, simple operation, convenient maintenance.

faults:

efficiency is low, usually about 30%, selection of up to 50%.

vacuum degree is low, it is not only limited to the structure, more important is limited to the working fluid saturation vapor pressure. With water as working fluid, the limit pressure can reach 2000 ~ 4000 mpa.

water ring vacuum pump energy saving;

1。 The higher the temperature, the greater the volume of a gas. When the vacuum degree of vacuum pump to achieve the same, its suction flow rate also will increase, which will result in the increase of load and energy expenditure. Therefore, control the temperature of the circulating water is very important, especially in the summer, this requires cooling system to keep good cooling effect. It is generally believed circulating water had better not more than 35 ℃. If the summer high temperature, cooling water flow rate can be appropriately increased, but at the same time, should pay attention to too much of the cooling water flow rate, can also result in increase of energy consumption, so the cooling water flow rate should be appropriate to reduce in winter.

2。 If the vacuum pump capacity significantly more than the demand of the vacuum system, there will be excessive vacuum, and the effective pumping speed of the pump will be wasted. PID control is used to adjust the frequency of the inverter, so as to adjust the mechanical pump pumping rate effectively, so as to achieve the goal of saving energy and reducing consumption.

3。 When the motor speed constant water level in a certain range, the formation of high water level water ring is larger, the low level of water ring is smaller. That is to say, when water ring is larger, the power consumption will increase, so the efficiency of water ring vacuum pump will be reduced, power consumption will increase. Regular monitoring of the surface of the water ring pump vacuum value, manual intervention water ring of water supply, water can ensure the maximum efficiency of vacuum pump ( Also can adjust PID) 。

4。 Internal wear: 3 - operation Five years later, as a result of the rotor and the distribution plate of wear and clearance between rotor and the pump shell increases, there will be a vacuum leak, resulting in a decline in intake capacity. Should be arranged rotor and distribution board repair or replacement, in order to prevent the

stop by vacuumizing ability increase energy consumption.

the operation of the water ring vacuum pump problem;

1。 In the papermaking industry, vacuum pump working medium ( The added fluid) Mainly is the water or water. The water hardness is usually higher in the north, and the metal ions in water is more complex, so the internal parts of the vacuum pump after a long period of physical and chemical processes to form scale. Vacuum pump of the scaling problem can be solved by series of cleaning. Vacuum system is completely clean with clear water after replacement, add 5% diluted hydrochloric acid and the appropriate system cleaner and maintain temperature in 45 ~ 50 ℃, cycle 2 hours, then add water cleaning series. General cleaning cycle for 3 months. At the same time, the anti-scaling agent can use for a long time, keep the impeller clean and clean the whole vacuum circulation system.

2。 Water ring vacuum pump vibration problem often appear, such as rupture disc, rotor blade scaling, coupling rubber pad damage, such as change of water ring. This can lead to vibration. In the process of downtime, investigate the need of the above questions one by one, to ensure early find and solve the problem of abnormal ahead of time.

3。 Water ring vacuum pump impeller pump can be reduced to below the pressure of the local area corresponding temperature of saturated vapor pressure of liquid, and liquid will evaporate, bubbles and eventually produce high-frequency water hammer. Suddenly or due to improper operation, the valve closed or open, lead to sudden changes in liquid velocity, direction and lead to pipeline pressure size again and again change sharply, lead to damage of water hammer and the metal surface. The measures to prevent cavitation impeller: ( 1) Increase the circulation of the suction nozzle area, reduce the flow velocity, increase the suction pressure. ( 2) Maintain reasonable reservoir water level (water separator, All water level 300 meters) below To avoid heat exchanger congestion, and ensure the proper vacuum pump liquid level height. ( 3) Try to shorten the vacuum pump suction pipe length, reduce unnecessary fitting, make the centerline of the pump as close to the steam separator liquid level. Saturated water absorption, should as far as possible the negative installation height, and should maximize height, to improve the pump inhalation can. ( 4) Use of cavitation resistance materials. When pump use condition is limited and can't completely avoid cavitation, should choose the cavitation resistance good materials ( Such as 2 cr13, copper alloy, etc. ) 。 ) Applied to manufacture impeller, or spraying in the pump casing and impeller flow channel surface in order to prolong the service life of the impeller. ( 5) After the occurrence of cavitation, must be timely repair impeller and the pump is going to the anti-corrosion material.