Noise reduction method of slide valve vacuum pump

Slide valve vacuum pump is also a kind of vacuum pump widely used in many vacuum equipment. It has the advantages of high pumping speed, simple structure, reliable function and high vacuum degree, so it has become a product with large demand. However, the primary problem of the pump is that the noise and oscillation are relatively large, which will have a bad impact on the environment of the operating unit, and will damage the service life of the vacuum system. 

Therefore, it is of great significance to improve the noise and function of the slide valve vacuum pump and extend the working life and power. According to the literature [discussion on the noise mechanism of the slide valve vacuum pump], it is known that the main reason for the high noise of the slide valve pump is the impact of oil and gas. In order to reduce the impact noise of the slide valve vacuum pump, the method widely used in China is to reduce the impact by lowering the rotating speed of the slide valve pump. For example, if the rotation speed of h150 slide valve pump is changed from 540r / min to 480r / min, the noise can be reduced by more than 3dba.

However, under the condition of constant pumping speed of slide valve pump, decreasing the speed of pump means increasing the volume of pump, which is obviously not a scheme. Therefore, it is necessary to explore other useful methods to reduce noise. The reference [acoustic manual] indicates that sound is transmitted in the pipeline, and when the cross-sectional area of the pipeline changes, the acoustic impedance Z also changes. At the variable cross-section, due to the change of impedance, part of the incident sound wave will be reflected back to the original pipe, and then the incident sound wave will be attenuated to achieve the effect of noise elimination. In the exhaust system of the slide valve vacuum pump, the air flow section changes many times from the exhaust hole of the pump cavity to the exhaust pipe of the oil tank. Assuming that the sound attenuation function of the variable cross-section pipeline is reasonably used, the impact noise of the underground sliding valve vacuum pump can also be used.

API 681 Vacuum Pump

Rotary Vane Vacuum Pump

Dry Scroll Vacuum Pump 

Characteristics of vacuum valve

The bottom features of vacuum valve are high air tightness (firm sealing); the resistance to air flow is as small as possible (i.e. the flow of the valve is fully conducted or large); the wear resistance of the sealing parts is good, which can be reused and has a long life; the valve body information and the amount of gas released from the sealing parts are small; the operation is flexible, simple, and the equipment is easy to clean. In addition, the function is reliable and the repair is convenient. On the ultra-high vacuum valve also required to be able to withstand high temperature baking (450 ℃); for the saving valve, it is required to regulate the gas flow evenly. 

Materials of commonly used vacuum valve bodies are metal and glass. Manual vacuum valve driving handwheel is made of high-strength plastics. Glass vacuum piston, also known as "cork", is generally used in glass vacuum system, small vacuum equipment, vacuum gauge regulation or calibration system. The advantages are simple production, convenient operation, easy cleaning and investigation, good chemical stability and insulation, and less outgassing. The vacuum equipment required by industrial production, such as vacuum coating equipment, vacuum exercise equipment, vacuum heat treatment equipment, space environment simulation equipment, rocket engine simulation equipment, satellite surface charged simulation equipment, particle accelerator and controlled nuclear fusion equipment, heavy duty vacuum equipment are required for industrial production Metal valves are used in particle accelerators.

Water Ring Vacuum Pump

Dry Scroll Vacuum Pump

industrial vacuum pumps,vacuum furnaces

Detailed analysis of eruption pump

The ejecting pump uses the principle of converting static pressure energy and kinetic energy into each other when the fluid is moving. It can be used not only for gas but also for liquid. In chemical production, eruption pump is often used for vacuum pumping, so it is also known as eruption vacuum pump. 

The working fluid of eruption pump can be steam or liquid. It is a steam eruption pump. The working steam is ejected from the nozzle at a high speed under high pressure. In the process of eruption, the static pressure energy of the steam is changed into kinetic energy, and the gas is sucked in under low pressure. After mixing with the steam, the aspirated gas enters into huansanfang, the velocity decreases gradually, and the pressure tension increases, and it is discharged from the pressure outlet after one fan.

The structure of the eruption pump is simple and tight, and there is no active part. However, the power is very low, and the steam consumption is large, so it is generally used as a vacuum pump, not as a pleasure delivery device. Because the transported fluid is mixed with the working fluid, its application scale is restricted.

If several jet pumps are used together, a higher vacuum can be obtained. It is a three-stage steam eruption pump. The working steam and mountain gas are absorbed into the inlet of the first stage eruption pump. The steam is condensed by the condenser, and the gas enters the second stage of the eruption pump. Then, it passes through the condenser, the third stage eruption pump and the condenser, and is finally discharged by the eruption pump. The auxiliary eruption pump is connected with the primary eruption pump in parallel to increase the starting speed. When the system reaches the specified vacuum degree, the auxiliary eruption pump can be blocked from the line. The condensate and cooling water in each condenser flow into the tank.

CL Sereis Cone Liquid Ring Vacuum Pump

Roots Blowers

Roots Vacuum Pump 

How to choose vacuum pump in vacuum system

In the planning and accounting of the vacuum system, people call the vacuum pump which directly extracts the vacuum container as the main pump, and the vacuum pump which insists on the pressure of the other pump below the critical pre stage pressure is called the front stage pump. In order to make the vacuum pump in the container to be pumped quickly from atmospheric pressure to the working pressure of the main pump, it is called pre pumping vacuum pump. For a vacuum system, the former stage pump of the system is often used as the pre pumping vacuum pump. The selection of pumps here refers to the selection of main pumps. In a narrow sense, it refers to the proper matching of the main pump with a reasonable front stage pump. In a broad sense, it includes the selection of the front stage pump and the pre pumping pump. The central equipment of vacuum system is vacuum pump, and the key process of vacuum system planning is pump selection and pump distribution. 

The main pump type, the first thing to consider is the feasibility and reliability of the problem, should be based on the vacuum pump to reach the limit of vacuum degree and operating vacuum (select the limit vacuum of the main pump is slightly higher than the limit vacuum of the vacuum chamber), according to the type of gas to be pumped, the proportion of each gas, and the gas mixed with dust and other conditions, select the true pump air that meets the process requirements. When two or more different types of pumps are suitable for the above conditions, we should select the economically reasonable vacuum pump according to the economic objectives such as initial investment and daily protection cost. Then, further comparison of environmental conditions and other conditions, selected. Therefore, it is necessary to start from the whole set of vacuum system and consider it comprehensively. It is necessary to recognize it only by comparing vacuum pumps.

API 681 Liquid Ring Compressor

Rotary Vane Vacuum Pump

Dry Scroll Vacuum Pump 

Dry screw vacuum pump

The screw vacuum pump has a recovery system, which is fully in line with the concept of energy conservation and environmental protection, and is more widely used. But why is the market share of dry-type screw vacuum pump not high? In addition to the price plateau, there are also users who do not have a good understanding of the dry vacuum pump and can not see the future economic benefits brought to the enterprise. This paper focuses on how to optimize the selection of dry vacuum pump? 

For these different types of dry vacuum pump, we are eager to be able to reduce its physical size. But this is in contradiction with the pumping rate of the vacuum pump, because the pumping rate of the vacuum pump is directly proportional to the volume of the vacuum pump. Small physical size means small volume. Of course, there is also an important factor that affects the pumping rate of vacuum pump, that is, the rotational speed. In order to match the pumping rate of small size vacuum pump with that of large size vacuum pump, it is necessary to increase its speed.

There are two ways to change the speed of vacuum pump, one is to change the frequency of power supply, that is to use frequency converter; the other is to change the transmission ratio of gearbox. The advantage of frequency converter is that it can provide a closed-loop control, but it is easy to cause torque loss under heavy load. Changing the gear ratio of the gearbox is a very economical method. Of course, it can only provide a single speed which is not controllable.

Water Ring Vacuum Pump

Dry Scroll Vacuum Pump

industrial vacuum pumps,vacuum furnaces

Waste heat recovery of air compressor

Air compressor in the process of work produces very large heat energy, but let it white out to the air is a very pity, so there is what we call air compressor waste heat recovery. The waste heat recovery of air compressor is to transfer the heat of high temperature oil of air compressor to cold water through superheat exchange technology. The cold water is heated and flows into the heat preservation water tank, so as to achieve the purpose of heat recovery. 

Because 73% of the heat energy of the air compressor is in the oil, and the technical treatment and heat exchange of the oil will produce a continuous stream of hot water, that is, the air compressor can work under constant temperature, and can meet the needs of the factory or life of hot water, kill two birds with one stone, and the hot water generated by the waste heat recovery technology of air compressor does not need any additional cost, which reduces the cost Less investment by factories to make hot water. Air compressor waste heat recovery is a very environmental protection and energy saving way.

CL Sereis Cone Liquid Ring Vacuum Pump

Roots Blowers

Roots Vacuum Pump 

Frequency conversion series air compressor chemical industry

Chemical industry in the production process often uses and produces corrosive gases, liquids and dust, a large number of flammable and explosive dangerous substances, as well as irritant, polluting and other toxic substances, so chemical plants are mostly built on water. In the design of building structure and production equipment will be considered in all aspects of anti-corrosion, fire, explosion-proof measures. With the rapid development of science and technology, modern chemical plants mostly use energy-saving, intelligent regulation and centralized control of chemical equipment. 

Clean and stable compressed air is indispensable in the complex production process of chemical plant. The compressed air from the air compressor is compressed and discharged into clean and stable gas after passing through a set of precise post-treatment system of gas storage tank, dryer and filter, and then divided into two pipelines: one is used to drive some pneumatic equipment, the other is used to produce nitrogen and chemical raw materials. Therefore, a high quality air compressor and post-treatment system will be directly related to the production process of the whole chemical plant.

API 681 Liquid Ring Vacuum Pump

Rotary Vane Vacuum Pump

Dry Scroll Vacuum Pump