Several Measures for Improving the Performance of Vacuum Pumps

1. Function of Inlet Regulating Valve of Vacuum Pump

Vacuum pumps are generally used for vacuum pumping, but not all occasions require the lower the vacuum, the better. In some cases, it is required to control in a certain vacuum range, or the pressure of the vacuum chamber is too low. Serious cavitation will occur in the pump chamber, resulting in pump vibration and noise, which will affect the use of the pump. F time can be added in the suction zone of the pump. When the above situation occurs, the vacuum regulating valve can be properly opened to alleviate the impact of vibration and noise, or to reduce the vacuum degree to meet the required vacuum requirements. This is a more reasonable way to apply vacuum pump.

2. The Role of Atmospheric Ejector

Any liquid has vaporization pressure at any temperature. The limit vacuum of water ring vacuum pump is related to the saturated vapor pressure of the liquid circulation in the vacuum pump. The lower the limit vacuum degree of vacuum pump is, the higher the limit vacuum degree is. From Figure 1, it can be seen that the vacuum state is formed in the cavity during the pumping process of vacuum pump 1-5. According to Dalton's law, liquid rings are stirred by impellers. We believe that when the inhaled gas is zero, the sum of saturated vapor pressure and inhaled gas pressure filled with liquid circulation in the 1-5 cavity is the lowest and the vacuum degree is the highest. At this time, the suction pressure of the vacuum pump is the lowest, and the vacuum degree of the cavity 1-5 is the highest. The pressure is the saturated vapor pressure of the liquid ring. Therefore, the minimum absolute pressure at the inlet of the vacuum pump must be the saturated vapor pressure as the liquid ring medium at that temperature.

3. Effect of Auxiliary Working Fluid System on the Performance of Vacuum Pump

The working fluid must be continuously replenished. However, in order to improve the performance of vacuum pumps, it is necessary to determine the way of replenishing working fluid and how to determine the flow rate and pressure of replenishing working fluid.

4. Reducing working fluid temperature and increasing vacuum degree of pumping unit

It is known that the vaporization pressure of the liquid has a great relationship with the temperature of the liquid. High temperature and vaporization pressure will lead to low vacuum of the pump. Therefore, lowering the temperature of the working fluid will help to improve the vacuum of the pump. For the high temperature workflow, it is necessary to reduce the temperature of the workflow by heat transfer to improve the vacuum degree of the vacuum pump. As shown in Figure 4. Taking water as an example, the saturated vapor pressure of water is 0.0233 bar at 20 o'clock and 0.1234 bar at 50 o'clock. The saturated vapor pressure of water has increased more than five times.

Piston Vacuum Pump

Oil Diffusion Vacuum Pump

Daily Management of Water Ring Vacuum Pump

The service life of the water ring vacuum pump is not only related to the quality of the pump itself, but also to its daily management. Therefore, regular management and maintenance of the water ring vacuum pump is indispensable. So, what are the daily management of water ring vacuum pump? Now let's introduce the water ring vacuum pump manufacturer to us.

1. Clean and change oil regularly: Kerosene or straight-run gasoline should be used to clean the water ring vacuum pump. After washing, all parts should be wiped, dried or dried with a blower. When changing oil, 100 or 1 clean vacuum pump oil should be selected. If replaced by other oil, the vacuum degree of the pump will be seriously affected.

2. Before starting the pump, check whether the rotation direction of the motor is correct, whether the lubrication system is reliable, and whether the amount of oil is appropriate.

3. In daily operation, we should ensure that the oil temperature does not exceed 75 C, and that there is not too much noise and vibration, otherwise we should stop the machine for maintenance.

4. The connection pipeline between pump and user system should be short and thick, and the elbows should be minimized. If there are elbows, all joints should be sealed strictly to ensure no leakage.

5. When stopping the pump, the valve connected to the vacuum system should be closed first, and the exhaust valve should be opened to avoid pumping oil being sucked back into the vacuum system, and then the power supply of the motor should be cut off.

The long-term and efficient use of water-ring vacuum pump is inseparable from our careful management and maintenance. When we use water-ring vacuum pump in our daily life, we should do well in the above points, so that the pump can be used in industrial production with high efficiency.

Liquid Ring Vacuum Pump

Roots Vacuum Pump

Cautions in the Use of Vacuum Pump System

Vacuum pump system and vacuum pump are inseparable. When different vacuum pump systems are used, they are matters needing attention. Knowing these, we can better use them. Now we have a detailed knowledge of some vacuum pump systems.

Firstly, the method of combining vacuum pumps should be: in special cases, one kind of vacuum pump can not meet our needs, so we should combine several kinds of vacuum pumps, so that their pumping effect is higher and they can complement each other. For example, some vacuum pumps are good at pumping hydrogen, but not good at pumping other gases, but the group is good at pumping other gases. When combined, the desired pumping effect will be achieved, which requires a vacuum unit.

Second, we should pay attention to the oil vapor discharged by vacuum pumps. Some vacuum pumps will discharged oil vapor. In places with high environmental requirements, there is no pollution at all. Oil-free vacuum pumps can be used or oil vapor can be discharged outside. During the use of vacuum units, there will be vibration. If the required environment can not have vibration, it is necessary to use a vacuum pump without vibration, or use other methods to make the vibration smaller. Vacuum pumps need to be maintained in the process of use, in order to make better use of it. Atmospheric pressure will also affect the work of the vacuum pump system, the working environment determines which kind of vacuum pump you use, oil-free vacuum pump, water ring vacuum pump and so on.

JZJA(P)LG Screw pump system

ZJZSK Roots Liquid Ring Vacuum Pump System

Vacuum unit models

Vacuum units have many models, it has many components, such as water tanks, check valves, etc. Vacuum pumps can be combined into many types of units, their energy consumption is very small, vacuum is also very high, and can be moved. Here we come to a specific understanding of the vacuum unit.

First of all, if the installation and placement position is very uneven, it will affect its work, should be installed in a very flat place, so there is no great noise, and is also good for the machine, heavy strength must be guaranteed. If you want to stop the operation of the equipment, the first step is to turn off the steam valve, stop the exhaust, and then open the vent valve, let the vacuum drop, so that the machine is not working, do not form a backdraft or damage the equipment.

Secondly, the tightness of the vacuum unit should be very good, otherwise it will be very harmful. If a lot of air enters the system and the machine does not immediately pump out the incoming air, the pressure and temperature of the gas will rise, the total efficiency of the unit will decrease, and more electricity will be consumed, and some parts can not be pumped out. Enough smooth operation.

Finally, even if the gas entering the vacuum unit system is pumped out immediately, however, the load of the vacuum pump will increase, which will waste electricity and water. The air entering will also increase the supercooling of the condenser, reduce other aspects, increase water-soluble oxygen and so on. Sometimes the equipment will be corroded.

JZPS Roots-Liquid ring Vacuum system

CVS Centre Vacuum System

Vacuum system for pumping steam

In the process of vacuum impregnation, vacuum drying and vacuum freeze-drying, water vapor and other condensable vapors are the main gases pumped out by vacuum system. The working vacuum is mostly 10-10-1 Pa. Roots pump and oil seal mechanical pump are usually used to pump air abroad. For this reason, in recent years, foreign oil-seal mechanical pumps have the index of maximum inlet pressure of water vapor (usually 103~3*103Pa), but domestic oil-seal mechanical pumps generally do not have this index, and some mechanical pumps equipped with gas ballast valves have weak backstop effect, gas ballast effect is not significant, can not achieve the purpose of pumping a large amount of water vapor, resulting in water steaming. Vapor condenses in pump oil in large quantities. Oil and water mix to form a white emulsion, which reduces the sealing and lubrication performance of mechanical pumps. Emulsion will make the inner part of the pump rusty, rusty iron powder into the oil is reddish brown, and circulate with the pump oil in the pump, which has a negative impact on the service life and limit vacuum performance of the pump.

Several common vacuum systems for steam extraction are:

(1) Steam ejector pump pumping system. Steam ejector pump is suitable for vacuum system with large exhaust volume. The system needs to be equipped with working steam source.

(2) Oil booster pump + oil seal mechanical pump. This system is not suitable for gas-phase drying of transformer, especially in oil booster pump, bare electric furnace is used strictly, otherwise open fire will easily cause explosion accident.

(3) ZJ Roots Pump + ZJ Roots Pump + Double-stage Water Ring Vacuum Pump, the pumping system can obtain higher limit vacuum and larger exhaust volume. However, the investment cost of the system is relatively high, and the working fluid of the water ring pump can easily flow back into the vacuum container. Moreover, the pumping efficiency of the water ring pump is low, and the unit power consumption of the water ring pump is 50% higher than that of the slide valve pump. For example, various types of Roots water ring vacuum units.

(4) Slide valve pump + water ring pump or ZJ Roots pump + sliding valve pump + water ring pump, because the sliding valve pump in the system is equipped with a front pump (water ring pump), which reduces the compression ratio, so water vapor rarely condenses in the sliding valve pump, but there are still shortcomings of item 3.

(5) ZJ Roots Pump+Rotary Vacuum Pump, because of its high efficiency air ballast valve, reliable oil-water separator and reasonably designed lubrication system, enables the system to operate continuously at the inlet steam pressure of 3000Pa. This is an economical and reliable vacuum system for pumping steam used abroad in recent years. For example, various types of Roots rotary vane vacuum units.

JZPX series roots-rotary pump system

JZJ2B Roots-Liquid Ring Pump System

Cautions for Operation of Vacuum Pump System

What should we pay attention to when using the vacuum pump system? Today we will introduce this knowledge to you, hoping that through our introduction we can better help you understand.

Before the vacuum pump system is put into operation, it is necessary to carefully check whether the fasteners in various parts are loosened or not, and if loosening occurs, the tightening must be corrected. Before starting, the water tank must be filled with water, open the inlet valve of the pump, and then run the anti-corrosion pump. It is strictly prohibited that the pump is dehydrated, idle and reversed to prevent damage to the seal, impeller and other parts of the pump body. Before the vacuum unit stops, it opens the vent valve or reduces the vacuum to less than 0.092 MPa before stopping. In order to prevent backdraft damage to check valve caused by excessive vacuum. If the check valve fails, please open the check valve cover and remove debris.

When using steam-water series jet vacuum unit, the steam valve should be opened before starting. When stopping, the steam valve should be turned off before stopping, so as to prevent damage to the water jet vacuum pump caused by excessive temperature. When installing steam pipeline in vacuum unit, the pipeline must be kept level to prevent water accumulation in the pipeline, otherwise the vacuum effect will be affected. The circulating water in the water tank should be replaced or supplemented frequently, and the lower water temperature should be kept as far as possible, because excessive water temperature will affect the exhaust volume and vacuum degree.

Closed Cycle Water Ring Vacuum System

JZP2H type Roots and piston Vacuum system

High Vacuum System

There are many kinds of vacuum application equipment, but no matter what kind of vacuum application equipment, there is a suction system to exclude the gas in the vacuum container, so as to obtain the required vacuum conditions in the vacuum container. For example, a container for vacuum treatment is connected with a vacuum pump by pipes and valves. When the vacuum pump evacuates the container, there must be a vacuum measuring device on the container, which constitutes a simple vacuum pumping system.

Simple vacuum system can only obtain the vacuum degree in the low vacuum range in the pumped container. When it is necessary to obtain the vacuum degree in the high vacuum range, a high vacuum pump is usually connected in series in the vacuum system. When a high vacuum pump is connected in series, valves are usually added to the inlet and outlet of the high vacuum pump, so that the high vacuum pump can keep the vacuum alone. If the series high vacuum pump is an oil diffusion pump, in order to prevent a large amount of oil vapor from flowing back into the pumped container, a trap - water cooling baffle is usually added at the entrance of the oil diffusion pump. According to the requirements, dust collector, vacuum relay gauge head, vacuum soft connection pipeline, vacuum pump inlet vent valve and so on can also be added to the pipeline, thus constituting a relatively perfect high vacuum system.

air-cooled roots-liquid ring vacuum system

Open Cycle Water Ring Vacuum System