Oil change operation of vacuum pump unit

Whether it is a vacuum pump unit or any other mechanical equipment, it is inseparable from lubricating oil, because lubricating oil can effectively help the equipment to work better. However, this lubricant cannot maintain its function for a long time. It needs to change the oil according to the use of the device. Because after a long time of work, the oil quality of the unit will be polluted by various external factors, otherwise, if the lubricating oil is replaced in time, the unit will be damaged. 

1. When the vacuum pump is equipped with replacement oil, the pump should be taken out of the vacuum system first.

2. After that, the end of the chassis motor should be raised. Open the oil drain plug to drain the oil. Turn the device to keep the exhaust port, let all dirty oil in the chamber drain out from the oil drain port, and then add new oil from the air inlet. Oil 100-500ml continuous rotation 5-10 rpm or more for internal cleaning, this operation 3-5 times.

3. After taking out the oil, cover the oil plug, put the pump horizontally, add new oil from the air inlet and oil hole, and change the oil.

4. When the vacuum pump is equipped with oil displacement, it is not recommended to start the motor for a long time. At this time, the exhaust valve will be too severe and fatigue.

5. When changing the oil of vacuum pump unit, kerosene, gasoline, alcohol, etc. should not be used for non disassembly cleaning of the pump.

6. If the pump stops for a long time, the exhaust hood should be removed and the exhaust plug should be closed to the air inlet and drained。

Water Ring Vacuum Pump

Dry Scroll Vacuum Pump

industrial vacuum pumps,vacuum furnaces

Water Ring Vacuum Pump Solutions to Leakage

Water ring vacuum pump leaks for different reasons, its treatment methods will also be different, not to identify a cause of leakage, under different circumstances, the leakage should be solved in accordance with the appropriate method, then we may have five reasons for leakage for you to briefly introduce its treatment methods.

1. Leakage of machine in operation

If a machine is found to be leaking, it must not stop its work immediately. It should be kept at the lowest stable speed, and water should be added to the inner side of the cooling system at the same time. (Note: when opening the nozzle cover, a cover should be placed above it to prevent steam from burning), so that the engine can cool down, run at a short time and at a slow speed, and drive to the nearby concealed place for removal.

2. Water leakage due to breakdown of vacuum pump shell

If the vacuum pump shell breaks suddenly and leaks water, or the internal parts are damaged and lose the pump function, the relevant parts can be replaced as appropriate to eliminate the failure.

3. The water ring vacuum pump itself is seriously damaged.

If the pump is badly damaged and there is no repair condition on the way, the inlet and outlet pipes of the stainless steel vacuum pump can be directly connected to make full use of the natural circulation of hot and cold water to temporarily keep the engine at normal temperature; or an inner tube or bucket can be used as a container to firmly fix it, and then two rubber pipes are introduced from the container, one of which is connected to the engine's water inflow. On the mouth, the other one is connected to the outlet of the engine. The other end of the two pipes is inserted into the container, and the rubber pipe should be fixed firmly.

4. Leakage due to cracks only in pump housing

If only the shell of the water ring vacuum pump cracks and leaks, the cracks can be cleaned up and then bonded with adhesives. In order to meet the emergency, egg white and cement can be mixed into a sticky mass and applied to the cracks, which can be used after several minutes of solidification.

If the water seal of the water ring vacuum pump leaks slightly due to improper sealing, but the wear is not serious, a sand cloth can be laid on the glass plate or flat plate, and the sealing surface of the water seal can be grinded flat, or the water seal of bakelite can be turned over and used again. However, it should be noted that the contact surface between the water seal and the pump body should be ground to ensure its sealing performance.

Piston Vacuum Pump overhaul

For the inspection of the piston vacuum pump, it is generally necessary to completely disassemble the pump, comprehensively check, and measure the gap between the slide valve and the pump body (normal clearance is 0.04~0.12mm); check the slide valve and guide pump eccentric wheel in the pump Whether there are cracks on the surface, cracks on the surface, and immediate replacement; all the seals in the pump are replaced; in the dynamic operation of the pump, the vibration tester can be applied to test the vibration of the pump every week. According to the measured data, It can preliminarily determine the wear condition of bearings, slide valves and other components. When the bearing movement accuracy is reduced, replace it to avoid the impact and friction between the slide valve and the pump chamber due to the wear of the bearing. A vacuum gauge is applied to the repaired mechanical pump to perform an ultimate pressure test to determine the performance and repair effect of the pump. For old pumps that have been used for a long time, the gap of the pump is greater than 0.1mm and less than 0.2mm. The ultimate vacuum requirement is not very demanding. Vacuum pump oil with a kinematic viscosity of 150mm2/s can also be used to meet the normal operation of the pump.

Due to the wear of the pump chamber, the pump with a gap between the spool and the pump chamber greater than 0.2mm needs to cooperate with the manufacturer of the pump. According to the wear condition of the pump chamber, the spool valve, eccentric wheel and guide rail are specially made to make The pump cavity maintains a normal clearance; if the pump cavity is worn and severely scratched, the pumping time and the ultimate pressure cannot meet the process requirements. The repair spare parts cost is close to about half of the new pump price, and the maintenance value has been lost. The new spool valve should be replaced. Vacuum pump.Roots-vacuum-pump-working-principle

rotary vane vacuum pump of application

Rotary vane vacuum pump is one of the basic equipment used to remove vacuum gas from sealed container. It can be used alone or as a pre pump for booster pumps, diffusion pumps and molecular pumps. It can be used in vacuum smelting, vacuum welding, vacuum impregnation, coating, vacuum drying, chemical and pharmaceutical industries, electrical vacuum devices and other vacuum operations.

Matters needing attention in rotary vane vacuum pump:

1. The pump can be operated continuously for a long time in the ambient temperature range of 5-40 C and inlet pressure less than 1330 Pa.

2. Pumps are not suitable for pumping gases containing excessive oxygen, toxic, explosive, corrosive to metals, chemical reactions to pump oil, and particulate dust. They are also not suitable for transporting gases from one container to another as transport pumps.

3. Pump at atmospheric pressure to 6000P a under the inlet pressure of continuous working time not more than 3 minutes, in order to avoid injection or lubrication caused by poor pump damage.Rotary-vane-vacuum-pump-in-vacuum-forming-and-laminating-process

Rotary vane vacuum pump rotor

Rotary vane vacuum pump is mainly composed of pump body (stator) and rotor. The rotor slot is equipped with more than two rotating blades, and the rotor is eccentrically installed in the pump cavity. The gap between the outer edge and the top surface of the pump cavity is 2-3 microns.

When the rotor of the vacuum pump rotates, under the action of centrifugal force, the rotary blade slides reciprocally along the groove and keeps in contact with the inner wall of the pump chamber. The pump chamber is divided into two or several variable volume workshops. When the rotor rotates clockwise, the volume of the suction chamber connected with the suction port increases gradually from zero, and the pressure of the gas in the cavity decreases. The suction gas is continuously inhaled from the suction port.

At the same time, the volume of the exhaust chamber connected with the exhaust port decreases from large to small, and the gas in the suction chamber is compressed. When the gas pressure is higher than the atmospheric pressure, the exhaust valve is pushed open to discharge the atmosphere. When the rotor rotates continuously, the pump will continuously exhaust.Roots_Vacuum_Pump

WHAT VACUUM PUMPS ARE IN THE VACUUM SYSTEM

Vacuum system is composed of vacuum chamber, vacuum pump or vacuum unit, vacuum pipe, vacuum valve, trap and other vacuum components, electrical control system, etc. It is widely used in electronic semiconductor industry, photoelectric backlight module, mechanical processing and other industries. The vacuum system is usually composed of several vacuum pumps, and plays a role in different fields according to their respective characteristics.

1. MAIN PUMP:
The main pump is a vacuum pump which is used to obtain the required vacuum degree to meet the specific technological requirements. According to the different limit pressure required by the vacuum system, the limit pressure of the main pump in the selection process is generally half to one order of magnitude lower than the limit pressure required by the system.

2. ROUGH PUMP:
Coarse pumps are vacuum pumps that start at atmospheric pressure and reduce the pressure of the pumped system to the point where the main pump system can start working.

The pressure reached by the crude pump must be less than the starting working pressure of the main pump. The crude pump can also be used as a front stage pump.

Roots Blower Of Introduction

Roots blower, also known as Roots blower, is a volumetric rotary blower, using two or three blade rotors in the cylinder for relative motion to compress and transport gas rotary compressor. The blower is simple in structure and convenient in manufacture. It is suitable for gas conveying and pressurizing in low pressure situations and can also be used as a vacuum pump. Its biggest characteristic is that when the pressure is adjusted within the allowable range, the flow rate changes slightly, the pressure selection range is very wide, and it has the characteristics of forced gas transmission. When conveying, the medium is not oily. It has simple structure, convenient maintenance, long service life and small vibration of the whole machine.

Due to periodic suction, exhaust and instantaneous constant volume compression, the gas velocity and pressure fluctuation will be caused, which will produce a larger aerodynamic noise. In addition, the clearance between the rotor and between the rotor and the cylinder will cause gas leakage, thus reducing efficiency. The exhaust volume of Roots blower is 0.15 to 150 cubic meters / minute, and the rotation speed is 150~3000 rpm. The single stage pressure ratio is usually less than 1.7, up to 2.1, and can be used in series.

Roots blower transport medium for clean air, clean gas, sulfur dioxide and other inert gases, special gas industries (gas, natural gas, methane, carbon dioxide, sulfur dioxide, etc.) and high-pressure working conditions of the preferred products. In view of the above characteristics, it can be widely used in metallurgy, chemical industry, fertilizer, petrochemical, instrumentation, building materials industry.

According to the shape of the rotor, roots blower is divided into two leaf type and three leaf type. The three leaf rotor is rotated and rotated by two rotors for three times at each rotation. Compared with the two blade type, the gas pulsation is small, the vibration is small, and the noise is low.
The speed of Roots blower is 150~3000 revolutions / min. The flow rate is 0.15-1200 cubic meters per minute, the pressure is 9.8-196 kPa, the power is 0.75-1000 kW, the single machine weight is 100-9000 kg.

Is It Scientific To Check Stainless Steel With A Magnet?

Like the 2BV water ring pump and the 2BE water ring pump, the SS304 material and SS316L material are often used.

Most end users do not have professional material testing equipment. Many customers prefer to use magnets to simply test the raw materials are stainless steel or cast iron.

In fact, it is unscientific to use a magnet for simple test.

1. S ometimes stainless steel is with magnetic when it is machined. Due to the magnetic properties generated during the process, the magnet is attracted.

2. There are many types of stainless steel. In general, austenitic stainless steel and austenitic precipitation hardened stainless steel are non-magnetic (magnets cannot be absorbed), and other stainless steels have ferrite and ferromagnetic (magnet can be sucked). Therefore, stainless steel cannot be judged only by the presence or absence of magnetism. For stainless steel, it is indeed stainless steel if it can match used the quality standards.

SELECTION OF MEDICAL VACUUM PUMP

The function of the vacuum pump is to extract gas molecules from the vacuum chamber, reduce the pressure of the gas in the vacuum chamber, so as to achieve the required vacuum. Generally speaking, there is a large range from the atmosphere to the very high vacuum, and so far no vacuum system can cover this range. Therefore, in order to meet the technical specifications of different products, work efficiency and equipment life requirements, different vacuum sections need to choose different vacuum system configuration.

Medical vacuum system is an important part of hospital design and construction. Its main application principle is negative pressure suction. In the construction of medical vacuum pump system, the selection of medical vacuum pump is different from the general selection of industrial vacuum pump. These differences mainly involve three aspects.

Application Of Vacuum Pump In Wood Drying

In various heating and drying methods under normal pressure, the color, aroma, taste and nutrients of the material are subject to a certain degree of loss due to the heat of the material. If the method of vacuum drying is used, the loss of quality can be reduced by the fact that the air is isolated under a negative pressure state, and a material which is susceptible to chemical changes such as oxidation during the drying process can better maintain the original characteristics. Vacuum drying is to place the dried food material in a closed drying chamber. While vacuuming with a vacuum system, the material to be dried is heated appropriately, so that the moisture inside the material diffuses to the surface through pressure difference or concentration difference. Sufficient kinetic energy is obtained on the surface of the material, and after overcoming the attraction between the molecules, it escapes into the low-pressure air of the vacuum chamber and is removed by the vacuum pump.

Vacuum drying, also known as analytical drying, is a drying method in which the material is placed under a vacuum condition, and the boiling point under a negative pressure state is appropriately heated or the material is solidified and then dried by a melting point by cooling. Vacuum drying technology has been widely used in the production of health foods, especially the extraction of natural product extracts, which are widely used for vacuum drying because many of the functional ingredients in natural products are not resistant to high temperatures. Vacuum drying technology, also known as vacuum drying, is a method of removing air in a closed container and drying it under reduced pressure.

Under the negative pressure state, the boiling point of the melting point decreases with the increase of the vacuum degree. At the same time, the vacuum pump gap is used to reduce the water vapor content, so that the water and other solutions in the material can get enough kinetic energy to leave the surface of the material. Vacuum drying Because the air is isolated under the negative pressure condition, the chemically changed materials which are easily oxidized during the drying process can better maintain the original characteristics, and the material can be better protected by vacuuming after injecting the inert gas.

Air Cooled Roots Vacuum Pump

Because of its special structure design, air-cooled Roots vacuum pump can operate reliably for a long time under high pressure difference and high compression ratio. Cooling gas from both sides of the pump body into the pump suction chamber, so that the pump will not appear because of compressed gas overheating, but the pump pumping performance has no impact. The rotor rotates in the pump cavity and completes the process of suction and exhaust. Coolers and motors are necessary accessories for each pump. The specifications of coolers and motors are determined according to different operating conditions.

The working principle of the air cooled roots vacuum pump:

Gas circulating cooling Roots vacuum pump is mainly composed of rotor 1, rotor 2, pump 4, cooler 7 and so on. Because of its special structure design, it can operate reliably for a long time under high pressure difference and high compression ratio. Cooling gas from both sides of the pump body into the pump suction chamber, so that the pump will not appear because of compressed gas overheating, but the pump pumping performance has no impact. The rotor rotates in the pump cavity and completes the process of suction and exhaust. Coolers and motors are necessary accessories for each pump. The specifications of coolers and motors are determined according to different operating conditions. Pumps can be used alone or in series with more than one pump, or with liquid ring vacuum pump and ordinary Roots vacuum pump in series into a unit to achieve higher vacuum to meet various technical requirements.

ROOTS WATER RING UNIT

Roots water ring unit is a pumping unit composed of roots pump as the main pump, water ring pump or Roots-Water ring unit as the front-stage pump. It can be used to extract not only ordinary gases, but also gases containing water, organic solvents or a small amount of dust. Compared with the general mechanical vacuum pump, not afraid of oil pollution, not afraid of water gas and dust, and compared with the general water ring vacuum pump, with a high degree of vacuum and pumping speed under high vacuum conditions

Roots Pump-Water ring pump vacuum unit is widely used in chemical industry, electronics, machinery, pharmaceuticals, food sublimation drying, high altitude simulation test and other vacuum systems.

Because the water ring pump with high efficiency and energy saving is used as the front-stage pump, the vacuum unit has the advantages of high efficiency, compact structure, no leakage, corrosion resistance and high protection level.

When the working fluid in the front-stage pump is changed into oil, the limit vacuum degree of Roots vacuum unit can be effectively increased (see parametric table). Roots oil-ring unit is a closed-circuit circulation system, which can reduce pollution and save water. Roots oil ring vacuum unit is widely used in vacuum impregnation, vacuum drying, vacuum degassing and so on.

The working fluid of the front-stage pump can also use organic solvents or other liquids, and the front-stage pump can be used as a closed-circuit circulation system, which greatly reduces the pollution to the environment and greatly improves the recovery of organic solvents. The ultimate vacuum degree is determined by the saturated vapor pressure of the working fluid.

Vacuum Pump Piping Arrangement And Installation

The newly installed vacuum pump pipeline must remove the impurities in the pipeline and install a filter screen. The open-type working fluid supply mode is to adjust the liquid seal level of the gas-liquid separator by manually adjusting the gate valve at the bottom of the gas-liquid separator. The liquid level of the gas-liquid separator will change when the water-ring vacuum pump is just started or when the discharge pressure changes. If the liquid level of the gas-liquid separator is emptied, the gas will be discharged from the bottom of the gas-liquid separator. If the gas is poisonous or inflammable and explosive, the gas will leak from the discharge gate valve of the gas-liquid separator, which will cause major safety accidents.

Installation of vacuum pump piping:

1.pipeline installation, especially the intake pipeline, first remove pipeline slag, rust and dirt.

2. for newly opened pipelines, 20-30 mesh / inch screen should be installed. The filter mesh is clamped between the two flanges of the pipeline, and the outer circumference of the filter mesh should leave a certain amount of clamping allowance to avoid being sucked into the vacuum compressor. After a period of time, confirm that there is no foreign matter in the pipeline.

3.The new pipeline filter mesh is easy to be blocked by impurities, which will affect the inhalation of gas. It should be removed and cleaned in time.

4.Generally, the first operation of a week, to stop cleaning the filter screen, and then run for three weeks, for the second cleaning, until the system is clean, you can remove the filter screen. The water supply pipeline should be cleaned with water before connecting to the vacuum compressor to ensure that the water pipe impurities are washed before connecting to use.

Vacuum pump start up:
1.The grease in the bearing cavity of vacuum compressor should be replaced before starting, and the bearing cavity should be cleaned with gasoline before replacing.

2.Wash the water in the vacuum compressor through the liquid supply pipeline, move the rotor by hand, and then drain the sewage through the liquid discharge pipeline. For units that have been commissioned or put into operation for more than two days, when restarting, wash them with water and coil, so as to avoid internal rust and scaling, which will cause difficulties in starting and burning the motor.

3.check whether the electrical part is safe and correct.

4.Check the rotation direction of the motor to make it conform to the steering of the liquid ring vacuum compressor.

5.check whether the coupling cover or belt cover is reliably fixed.

When the operation of the vacuum compressor is stable, adjust the gate valve to make the reading of the pressure gauge of the liquid supply pipeline consistent with the discharge pressure of the vacuum compressor. At this time, slowly close the gate valve. When the reading of the discharge pressure gauge is unstable, it shows that the liquid supply is insufficient. Slowly open the gate valve, when the reading of the pressure on the discharge side is stable, at this time For the best liquid supply, write down this readout, and then read it every time you turn on the machine. The speed of the regulating gate valve must be slow, because it takes several minutes to reflect the change from the amount of liquid supplied to the performance of the vacuum compressor.

PUMPING RATE OF ROOTS VACUUM PUMP UNIT

Roots water ring vacuum unit is made up of roots pump main pump and water ring pump as series pump.

The water ring pump is more advantageous than other vacuum pumps in Roots water ring vacuum unit. It overcomes the limit pressure difference (the limit pressure of the unit is much higher than that of the water ring pump) when a single water ring pump is used, and has the disadvantage of low pumping rate under certain pressure. At the same time, it keeps the Roots pump working quickly and pumping greatly. The advantages of gas rate.

Especially suitable for pumping a large number of condensable steam, especially when the gas-filled oil seal mechanical vacuum pump is not enough to remove condensable steam, or the use of solvent can deteriorate the performance of the pump oil, or the vacuum system does not allow oil pollution more obvious. When equipped with explosion-proof motors and electrical appliances and comply with the corresponding safety rules, flammable and explosive gases can also be extracted.

Roots Vacuum Pump Unit in the selection of time to consider a variety of parameters, such as its efficiency, pumping rate and other issues, each problem may be the cause of equipment failure, therefore, in order to better use the equipment, we need to further understand and understanding of it, today I focus on for you to enter A simple analysis of the pumping rate of Roots vacuum pump unit is hoped to be helpful to all of you.

Vacuum Pump Ultimate Pressure

The function of the vacuum pump is to extract gas molecules from the vacuum chamber, reduce the pressure of the gas in the vacuum chamber, so as to achieve the required vacuum.

The function of the vacuum pump is to extract gas molecules from the vacuum chamber, reduce the pressure of the gas in the vacuum chamber, so as to achieve the required vacuum. Generally speaking, there is a large range from the atmosphere to the very high vacuum, and so far no vacuum system can cover this range. Therefore, in order to meet the technical specifications of different products, work efficiency and equipment life requirements, different vacuum sections need to choose different vacuum system configuration.

The absolute pressure of vacuum pump means absolute pressure, which is the real vacuum pressure generated by vacuum pump. Absolute vacuum is absolute vacuum pressure. Absolute pressure = local atmospheric pressure + surface pressure (relative pressure), the smaller the absolute pressure is, the closer to vacuum!


Limit vacuum indicates that there is no substance (including molecule, atom, etc.) in this state, which is only a state of existence in theory and is impossible to achieve; it is an important parameter of vacuum pump, is the characteristic value of the pumping capacity of reaction pump, is a value related to vacuum pump, different vacuum pumps can have Different limiting vacuum; it is a concept in theoretical research and an ideal vacuum state refined by excluding the influence of various practical factors. So they are two different descriptions of the vacuum degree of the vacuum pump.

Ultimate pressure of vacuum pump:

The partial pressure is the pressure of the non condensable gas in the gas. The total pressure refers to all gases in the gas.

The pressure of the pressure. In vacuum applications, partial pressure and total pressure have their own application areas. Study on the current vacuum pump

In the nuclear standard, if the total pressure is not specified, the limit pressure index is all partial pressure. 10-3 Torr = 1.33 * 10-1 PA slide valve pump and rotary vane pump can reach; now domestic and foreign rotary vane pump can be 6 * 10-2 Pa Avenue

What Is The Piston Vacuum Pump

Piston Vacuum Pump is a kind of variable capacity gas transmission pump. It has the advantages of good energy saving effect, high vacuum and large pumping capacity. In addition, compared with rotary pump, the durability of the slide valve pump has more advantages.

What is the piston vacuum pump：

Slide valve pumps have single-stage H-type, two-stage 2H-type slide valve vacuum pumps for the suction of air and other general gases, when the use of gas ballast, can also suck containing a small amount of palm condensable gases (such as water vapor). Additional devices should be used when sucking gases that contain excessive oxygen, are explosive, are corrosive to ferrous metals, and react chemically with vacuum oil.

Application range of piston vacuum pump:

This type of pump can be used alone, also can be used as diffusion pump, oil booster pump, roots pump and other high vacuum pump front pump, relative to rotary vane vacuum pump, H type slide valve pump is more durable, long service life. The pump is widely used in vacuum coating, vacuum heat treatment, vacuum sintering, molecular distillation and aviation simulation test.

Oil Diffusion Pump Operation

Oil diffusion pump is a vacuum pump using low pressure, high speed and directional flow of oil vapor jet. The limit vacuum of this pump is 10-4-10-5 Pa, the working pressure range is 10-1-10-4 Pa, the pumping speed range is several hundred thousand liters/sec (1 liter = 10-3 m 3). Oil diffusion pump is the main equipment to obtain high vacuum. It is widely used in vacuum smelting, vacuum coating, space simulation test and some vacuum systems insensitive to oil pollution.

Operation procedure of oil diffusion pump:

The operation of the oil diffusion pump includes two operations: opening the pump and stopping the pump.

The pump opening sequence of oil diffusion pump:

1. Turn on the cooling water of the diffusion pump, pre-vacuum with the mechanical pump, after the pressure of the diffusion pump is lower than 10-1Pa, turn on the power supply of the diffusion pump to heat the electric furnace and heat the diffusion pump.

2. For small pumps below K-400, the pump can work normally after 45 minutes of heating, and for large pumps between K-500 and K-1200, it needs 45-65 minutes of heating before it can work normally. Therefore, when using the diffusion pump vacuum system, we should pay attention to arranging the start-up time of the diffusion pump.

3. open the diffusion pump population valve, the pump can work normally.

2SK Liquid Ring Vacuum Pump

The 2SK-P1 series two-stage liquid ring vacuum pump-air jet pump unit mainly works under the adiabatic pressure of 10-50mmHg, but its efficiency is low in the high vacuum region. If the Roots water-ring vacuum unit is needed for long-term operation, the best pumping efficiency in the high vacuum region can be obtained.

2SK liquid ring vacuum pump and 2SK-P1 series two-stage liquid ring vacuum pump-atmospheric jet pump unit are used to pump air and other non-corrosive, water-insoluble, non-solid particles in order to obtain a higher vacuum in an airtight container.

2SK liquid ring vacuum pump is widely used in food, textile, chemical, pharmaceutical and metallurgical industries and electronic fields such as vacuum evaporation, vacuum concentration, vacuum moisture regain, vacuum impregnation, vacuum drying and vacuum smelting.

The 2SK series is used for working conditions with suction pressure below – 0.08MPa, and the 2SK – P1 series is used for working conditions with suction pressure below – 0.096MPa.

Features of 2SK liquid ring vacuum pump：

1. Compared with SK series single-stage liquid ring vacuum pump, it has the characteristics of high vacuum and high pumping speed in high vacuum region.

2. Under the same pumping speed, the shaft power is obviously higher than that of 2BV and 2BE series water ring vacuum pumps.

3. because the structure is a double leaf wheel structure, manufacturing and maintenance are more complex and more vulnerable parts.

Screw Pump Of Technology

At present, the development of various vacuum pumps is increasingly affected by vacuum applications. The general vacuum system can not meet the requirements of clean and oil-free corrosion resistance. Therefore, in recent years, the market demand of dry vacuum pumps is very large. Vacuum products have been replaced. A large number of oil-free vacuum systems have been replaced by oil-free vacuum systems. Clean vacuum system instead.

Dry screw vacuum pump has become the preferred vacuum acquisition equipment in the microelectronics, semiconductor, pharmaceutical, precision processing and other industries in Europe, the United States and Japan due to its superior performance. On the basis of screw compressor, Japan developed the multi-head rotor profile of vacuum pump very early and put it into the market. Several German vacuum equipment companies have gradually developed rotor profiles with constant pitch and variable pitch, and have done a lot of research on rotor and body cooling.

The structure of dry screw pump:

The structure of screw vacuum pump is mainly composed of screw rotor, shell, cooling cycle and sealing material. The drive shaft is connected with the active rotor, and the driven rotor is rotated by the synchronous gear. A cooling water channel is opened on the shell to cool the rotor and the exhaust temperature, and the synchronous gear and the bearing oil are lubricated. The bearing and housing are sealed by seals to achieve an oil-free effect. The dry screw vacuum pump is similar to the oil-free screw compressor in sealing and lubrication.

Key technical problems of screw pumps:

The exhaust port of the general vacuum pump is mechanically sealed, and the inlet side is commonly used with double lip seals. In the transmission mode, the current general is the direct-connected motor, with a coupling and rotor connection, very few belt or chain drive. The exhaust temperature of constant pitch screw pump is very high (about 110 degrees) because of no internal compression process. If the cooling effect is not good, the rotor and casing will deform, affecting the sobbing effect. So the cooling casing is an indispensable link, and water cooling is the most common method. Through cooling water on the outer side of the bearing body, the cooling shell can be cooled and the rotor can be cooled. The water cooling of the rotor inside the rotor increases the life of the rotor and achieves a good cooling effect. But the structural design (two stage) requires a certain level of technical and processing support. Water cooling sometimes can not achieve cooling effect, so usually near the exhaust end of the rotor cooling gas (mostly nitrogen).

Now the mainstream screw vacuum pumps abroad use this method. This method has several advantages: firstly, it can cool the rotor casing and reduce the exhaust temperature; secondly, when the gas contains particulate matter, it can prevent the deposition of particulate matter or chemical reaction causing explosion.

Diffusion Pump System

Diffusion pump is currently one of the most widely used and most important tools for obtaining high vacuum, usually referred to as oil diffusion pump. Diffusion pump is a secondary pump. It needs mechanical pump as the front stage pump.

Common faults of the diffusion pump system and their elimination measures:
(1) If the diffuser pump pumping system does not leak and the limit pressure of the system has not reached the expected results, it may be unreasonable system design and low effective pumping speed; or the electrode bleeding of the vacuum gauge and the vacuum gauge itself are limited by photocurrent and can not measure the low pressure.

(2) If the pumping performance of diffusion pump or unit deteriorates gradually after long-term use, that is, the limit vacuum degree and pumping speed decrease, and other normal conditions, the diffusion pump oil is gradually oxidized and the quality deteriorates. At this time, new diffusion pump oil should be replaced. The oil change step is: first unload the diffusion pump, take out the pump core, according to the requirements of the pump core cleaning and drying after the correct assembly and adding new oil.

(3) When the diffusion pump suddenly leaks into the atmosphere due to special reasons, such as bursting of vacuum gauge tube, misopening of the vacuum vessel vent valve or not closing the high vacuum valve, the high vacuum valve should be closed immediately, the diffusion pump should be stopped heating and the oil pan should be forced to cool down. After the failure is eliminated, the pumping test should be performed and the pump oil should be replaced according to the result.

(4) After the diffusion pump is disassembled and assembled into the system, if the system is pumped strictly according to the aforementioned operating procedures, it should be able to reach the original limit pressure of the pump; if the gap between the nozzles is carefully adjusted repeatedly, the vacuum should also be increased. If the vacuum can not be pumped, first check whether the leakage rate of the pump system is over the allowable value; at the same time check whether the heater of the diffusion pump is burned out, whether the supply voltage is normal, whether the cooling of the pump is normal. If all the above aspects are normal, it can be considered as a pump core assembly problems, such as the installation of misalignment, nozzle clearance is not correct, the pump core is not cleaned before assembly, organic solvents are not dried, pump oil is not enough or installed with poor quality pump oil and heating power adjustment is not correct.