Pollution free and efficient vacuum, pharmaceutical enterprises prefer screw vacuum pump

 

Vacuum distillation is a vacuum process often used in various chemical, pharmaceutical and petrochemical enterprises. At present, more and more enterprises fall in love with screw vacuum pumps in the process of selecting vacuum pumps for vacuum distillation, from chemical enterprises to various pharmaceutical enterprises. Recently, a well-known domestic pharmaceutical enterprise added another 18.5kw dry screw vacuum pump for vacuum distillation.
With the improvement of social quality requirements for various industries, product defects will be amplified and the tolerance will be lower and lower. This is especially true for pharmaceutical products. Therefore, in vacuum distillation, in order to improve the distillation efficiency and improve the quality of distillation products, more and more pharmaceutical enterprises no longer pay attention to the pumping speed and vacuum degree, but also pay attention to the improvement of product quality by clean vacuum in the process of vacuum pump selection.
The working range of dry screw vacuum pump is from atmospheric pressure to about 1pA extreme vacuum. It has a wide range of large pumping speed. A single pump with low vacuum can achieve high pumping speed. It has simple and reliable structure and convenient maintenance and operation. On the other hand, due to the inherent cleaning characteristics of screw vacuum pump, there is no need for other media to participate in the extraction process, and there is no need to worry about backflow polluting media. Moreover, it can be combined with roots to form a dry vacuum unit product with clean, high vacuum degree and large pumping speed. In food, fine chemicals, pharmaceutical semiconductors and other fields with strong demand for clean vacuum and various recycling fields, these characteristics can effectively improve the production efficiency of enterprises, greatly simplify the operation process and various supporting links of vacuum system, and improve the product quality. Therefore, they are favored by enterprises.

Liquid Ring Vacuum Pumps Used in Paper Mill in Bengal

Do you know the maintenance of oil-free screw vacuum pump

 Oil free screw vacuum pump has become one of the most widely used vacuum pumps in the market. It is welcomed by the public because of its characteristics of no oil fume, light weight and no pollution. However, many people do not know how to maintain it. The following small series will give you a popular science about the maintenance of oil-free screw vacuum pump.

1. There shall be sufficient and good ventilation conditions and ambient temperature below 40 ℃.
2. Clean the workplace without dust and dirt.
3. Water, oil and other liquids will not fall on the pump.
4. Not directly exposed to the sun.
5. There is enough surrounding space to facilitate the inspection, maintenance, assembly and disassembly of the pump.
6. The pump must be installed on a flat surface.
7. Install the pump on a hard concrete foundation. If there is no equipment, it can be installed on a steel frame or wooden frame.
8. It must be able to ensure that the pump does not vibrate due to the weak economic foundation.
9. The pipeline connected with the pump should not be too long or smaller than the pump inlet diameter, which will affect the pumping speed. At the same time, it is necessary to pay attention to safety and check the vacuum connection and whether the pipeline has air leakage.
10. When wiring, pay attention to the wiring requirements on the motor nameplate. Pay attention to the rotation direction of the motor for the three-phase electric pump, which shall be consistent with the direction of the arrow on the pump.
The above is about the maintenance of oil-free screw vacuum pump. I believe you will understand it after reading it. You should pay attention to these situations in your daily work to avoid accidents.

Liquid Ring Vacuum Pumps Used in Paper Mill in Bengal

Reasons for sudden non operation of water ring vacuum pump

Generally speaking, the water ring vacuum pump in normal operation will not have any problems, but this is not allowed. Sometimes, the pump in normal operation will suddenly stop running, and this situation is not caused for no reason. There are still many reasons:
1. The power failure may also be the reason why the water ring vacuum pump suddenly does not run. First check its power supply to see if it is powered off, eliminate the fault in time and restore the power supply.
2. The reason why the water ring vacuum pump suddenly does not run may be that the control protection switch of the vacuum pump trips. The main reason for the control protection switch tripping is that the vacuum pump is damaged during operation or due to overload of the vacuum pump motor. The treatment method for the sudden non rotation of the vacuum pump is to measure the insulation resistance of the vacuum pump motor first, and check whether the stator winding of the vacuum pump motor is damaged and whether other parts are damaged.
3. The broken core wire of the power supply cable of the water ring vacuum pump may also be the reason for the sudden non rotation of the vacuum pump. The treatment method for the sudden non rotation of the vacuum pump is to connect the broken core wire of the motor power supply cable and wrap it with insulating tape. If the connection repaired after the power supply cable is broken needs to be immersed in water, the cable shall be treated or replaced according to the waterproof connection and sealing requirements of the cable joint.
4. The action of the thermal protector of the water ring vacuum pump may also be the reason for the sudden non rotation of the vacuum pump: the main reason for the action of the thermal protector of the vacuum pump is the overload of the vacuum pump or the poor heat dissipation or dehydration operation of the vacuum pump motor; Or it is caused by malfunction of thermal protector. The treatment method is to check the cause of the action of the thermal protector and eliminate it, waiting for its automatic reset or repair and adjustment.
5. The stator winding of the water ring vacuum pump is burnt out, which may also be the cause of the sudden non rotation of the vacuum pump. If it is found that the stator winding of the vacuum pump is burnt out, first check the cause of the damage of the stator winding and eliminate the fault to prevent the motor stator winding from being damaged again; Then disassemble and repair the motor stator winding and replace the damaged stator winding as required.
7. There may also be the reason why the motor is burnt out due to water ingress caused by medium corrosion. The liquid is corrosive. It is recommended to use stainless steel.
Therefore, once the water ring vacuum pump used by everyone has such a situation, what to do is always careful and careful inspection. The inspection results determine which way we will choose to deal with it, so that we can continue to use the vacuum pump.

LGB220 Dry screw vacuum pump Used In Chemical plant In Thailand

Function of dry vacuum pump

In the process of expanding the development advantages of enterprise productivity, we should constantly improve the advantages of the actual performance of dry vacuum pump products and speed up its application effect. The overall driving force of its product application and practical ability is to continuously improve the overall development of its product strength, and improve the application efficiency of the equipment through comprehensive driving product advantages.
Therefore, its performance capability in all aspects is continuously improved, and its practical advantages are brought into full play, so as to enhance the embodiment of its product strength and further improve the comprehensive performance of its products
Improve product application and performance advantages. Give full play to the quality and strength of dry vacuum pump, accelerate the embodiment of its product performance and superior ability, and use advanced equipment to expand the development of enterprise productivity. Continuously display and expand the practicability and quality strength of products, improve their overall application value strength with efficient product utilization effect, so as to improve the superiority of product strength with reliable quality and effectiveness, and fully improve the quality strength of product use and sustainable development.
In order to speed up the development of enterprises and improve the performance of dry vacuum pumps, we should speed up the application and practice of products with various advantages. The improvement of performance advantage level promotes the overall improvement of enterprise quality and strength, and enhances the quality and performance of enterprises through reliable strength utilization.
Now, you can see that there are so many different designs of dry vacuum pumps, each with its own characteristics, advantages and disadvantages.
Application cost has always been an important factor affecting people's selection of vacuum pump. More and more vacuum pump users realize that the stability of vacuum pump should also be taken into account. Due to the accidental wrong solution of the vacuum pump, the application efficiency of the machine is reduced, which affects the production and delivery of wafers, and even the processing damage of wafer waste and other parts. Because the screw design adopts single-stage design, the number of parts used can be reduced by up to 60% compared with multi-stage pumps (such as ball joint, claw and combination). This is a great advantage for stability and future protection costs.
In general, if the user thinks that power consumption is very important to him, selecting an internal compression screw may be a good choice, and the nitrogen content is not important to him. However, in general, the requirements for tail gas treatment are becoming more and more stringent, so it is particularly important to reduce the amount of nitrogen used in the future. If you want to handle a wide range of semiconductor processes without changing them with a simple inventory control pump, external compression screws are a good choice.

Water Ring Vacuum Pumps Used In Vacuum Drying Of Vegetable And Fruit 

Reasons for sudden non operation of water ring vacuum pump

Generally speaking, the water ring vacuum pump in normal operation will not have any problems, but this is not allowed. Sometimes, the pump in normal operation will suddenly stop running, and this situation is not caused for no reason. There are still many reasons:
1. The power failure may also be the reason why the water ring vacuum pump suddenly does not run. First check its power supply to see if it is powered off, eliminate the fault in time and restore the power supply.
2. The reason why the water ring vacuum pump suddenly does not run may be that the control protection switch of the vacuum pump trips. The main reason for the control protection switch tripping is that the vacuum pump is damaged during operation or due to overload of the vacuum pump motor. The treatment method for the sudden non rotation of the vacuum pump is to measure the insulation resistance of the vacuum pump motor first, and check whether the stator winding of the vacuum pump motor is damaged and whether other parts are damaged.
3. The broken core wire of the power supply cable of the water ring vacuum pump may also be the reason for the sudden non rotation of the vacuum pump. The treatment method for the sudden non rotation of the vacuum pump is to connect the broken core wire of the motor power supply cable and wrap it with insulating tape. If the connection repaired after the power supply cable is broken needs to be immersed in water, the cable shall be treated or replaced according to the waterproof connection and sealing requirements of the cable joint.
4. The action of the thermal protector of the water ring vacuum pump may also be the reason for the sudden non rotation of the vacuum pump: the main reason for the action of the thermal protector of the vacuum pump is the overload of the vacuum pump or the poor heat dissipation or dehydration operation of the vacuum pump motor; Or it is caused by malfunction of thermal protector. The treatment method is to check the cause of the action of the thermal protector and eliminate it, waiting for its automatic reset or repair and adjustment.
5. The stator winding of the water ring vacuum pump is burnt out, which may also be the cause of the sudden non rotation of the vacuum pump. If it is found that the stator winding of the vacuum pump is burnt out, first check the cause of the damage of the stator winding and eliminate the fault to prevent the motor stator winding from being damaged again; Then disassemble and repair the motor stator winding and replace the damaged stator winding as required.
7. There may also be the reason why the motor is burnt out due to water ingress caused by medium corrosion. The liquid is corrosive. It is recommended to use stainless steel.
Therefore, once the water ring vacuum pump used by everyone has such a situation, what to do is always careful and careful inspection. The inspection results determine which way we will choose to deal with it, so that we can continue to use the vacuum pump.

Vacuum unit-vacuum pump preventive maintenance

How to judge whether the vacuum pump leaks in vacuum pump maintenance

How to judge whether the vacuum pump leaks? The vacuum pump maintenance manufacturer summarizes the following points:
1. Check whether the gravity return water of feed pump with vacuum pump speed regulation can be introduced into the condenser. If the return water volume is small and the water seal bag cannot be sealed, the gravity return water of the sealing water of the feed pump shall be poured into the gutter.
2. Vacuum pump maintenance: check whether the vacuum damaged door is closed and there is no leakage.
3. Check whether there is air leakage in the local area where the suction pipe of the vacuum pump is connected with the cylinder. The load decreases, the vacuum degree decreases, the load increases, and the vacuum degree increases slightly.
4. Vacuum pump maintenance: check whether the drain valve on the steam side of the condenser is closed and there is no leakage.
5. Check whether the water level of low-pressure heater under negative pressure is normal and whether the drain valve is tight.
6. Vacuum pump maintenance: check that the water level gauge of the vacuum system is not cracked or leaking.
7. Check whether the water seal, pipeline, flange or joint of the vacuum system valve are not tight, especially the pipeline and valve opening from the expansion tank or boiler start-up separator to the condenser.
8. Check the exhaust safety valve of the low-pressure cylinder of the vacuum pump.
The vacuum pump maintenance manufacturer shows that the leakage of the general vacuum pump is caused by the following conditions.
1) The sealing of vacuum pump is not tight: tighten all connecting bolts, tighten the packing gland, and wrap the connection between pipes and instruments and other components. Or replace the gasket and filler. For air leakage, oil lime can also be applied as a temporary remedial measure.
2) Bearing skew: this phenomenon causes the impeller to be installed obliquely in the pump body. For single acting pumps, the axial clearance is uneven. When the shale rotates, part of it will inevitably rub with the side cover, scratch the side cover and impeller end face, and increase the axial clearance. When the gas in the compression chamber passes through the expanded gap, a large amount of gas leaks into the suction chamber, which reduces the vacuum or exhaust pressure. At this time, remove the bearing for repair, and then install it correctly.
3) Vacuum pump maintenance: the front and rear side covers are misaligned. It may be that the front and rear side covers of the vacuum pump are misaligned, and the consequences are the same as the skewed bearings.
4) Heating of vacuum pump: with the increase of vacuum pump temperature, the saturated vapor pressure also increases, which will reduce the vacuum degree, but has no effect on the exhaust pressure.

The relationship between different casting processes and prices of liquid ring vacuum pumps 

Development of water ring vacuum pump

The development of water ring vacuum pump enterprise focuses on the advantages of products. In the practical application of water ring vacuum pump, the company fully reflects the advantages of products with strong technical ability. Many years of design and production experience has thoroughly demonstrated the application strength of the whole product and reflected the performance of the product in the use process of each user. In the face of the feedback, many people give positive replies to the product. Its application not only drives the company, but also improves the development of various industries, Further realize the advantages and strength of product development. Through the production expansion of water ring vacuum pump, in order to increase the effective improvement of the practical application capacity of the product, the company takes the reliability and stability of the product as the basis for development according to the demand capacity of its users, so as to develop the overall performance of the practical value of the product, and enhance the application effect in all aspects with the advantages of the product, so as to contribute to the future development of the product, Provide reliable basic capability, so we should promote the superiority of its application capability with the advantage of product performance. Increasing the performance of the practical capacity of the water ring vacuum pump, taking the application of the product as the basis for development and enhancing the use capacity of its products is an effective improvement of the production capacity of the enterprise. Therefore, to increase the promotion of the water ring pump, it is necessary to increase the development of the whole production foundation and improve the effective promotion of the actual development of products.

Roots Vacuum Pumps of Common Faults

Understand the causes of wear of screw vacuum pump and reduce wear

 

The screw vacuum pump must be installed in a position with ventilation and keep the pump body at a certain level to ensure smooth operation and low vibration of the vacuum pump; The exhaust nozzle of the screw vacuum pump is connected to the outdoor with a leather pipe to avoid oil vapor polluting the environment and reduce pollution. So how much do you know about the causes of screw vacuum pump wear? Here are some reasons for the wear of screw vacuum pump, including the following aspects: The operation of screw vacuum pump is relatively stable in the actual use process, but some users react that serious wear occurs when the vacuum pump runs for a long time, and serious wear affects the production and use effect of vacuum pump. At this time, we should understand the causes of wear, and then reduce wear as much as possible. 《1》 Because the material is not plasticized uniformly, or metal foreign matters are mixed in the speculation, the rolling torque of the screw of the screw vacuum pump is suddenly added, which exceeds the strength bearing capacity of the screw, resulting in wear. 《2》 When granular plastics enter the barrel from the hopper, they will first reach the feed section. Dry friction is inevitable in the feeding part. When these plastics lack heat and melt unevenly, it is easy to form the inner wall of the screw vacuum pump barrel and the external wear of the screw increases. 《3》 If there are fillers such as calcium carbonate and glass fiber, the wear of screw and barrel can be accelerated. 《4》 In the shrinkage and homogenization part, if the melting state of the plastic is disordered and uneven, the wear will increase. 《5》 Because some plastics are reinforced, such as glass fiber, minerals or other fillers. Compared with molten plastics, these substances have greater friction against metal materials. 《6》 The screw of screw vacuum pump rolls in the barrel, and the conflict between materials and barrel leads to the gradual wear of the working appearance of screw and barrel. The diameter of the screw decreases gradually and the diameter of the inner hole of the cylinder increases gradually. In this way, with the gradual wear of the screw and barrel, the diameter gap between the screw and barrel gradually increases. 《7》 If high-speed conversion is used to increase the shear force of plastic during injection molding, it will also produce corresponding tear fibers in the reinforcement. The torn fiber contains sharp ends, which will greatly increase the wear force. 《8》 When inorganic minerals slide at high speed on the metal surface, their scraping effect is not small. So the speed should not be too high. 《9》 Since the resistance of the head and deflector in front of the barrel does not change, the leakage flow of extruded material is increased, that is, the material flow increases from the diameter gap to the feed direction.

2X-A Two Stage Rotary Vane Piston Pump used in District Cooling

Do you know the vacuum degree of the vacuum pump?

Air extraction
The pumping volume is a measure factor of the pumping speed of vacuum pump. General units are L / s and m ³/ H. It is a parameter to make up for the air leakage rate. It is not difficult to understand why a vacuum pump with large air volume can easily pump the vacuum we need, while a vacuum pump with small air volume is very slow or even unable to pump the vacuum we want? The pipeline or container can never be absolutely free of air leakage, and the large air extraction makes up for the decrease of vacuum caused by air leakage, and the air volume can easily reach the ideal vacuum value.
Vacuum pump
vacuum degree
It indicates the degree of gas dilution under vacuum, which is usually expressed by pressure value. The vacuum degree value indicates that the actual value of the system pressure is lower than the atmospheric pressure. The value expressed from the table is also called the table pressure, which is also called the limit relative pressure in the industry. In practical application, the vacuum degree usually has two versions: absolute vacuum and relative vacuum. The value read from the vacuum gauge is called vacuum degree. Vacuum degree = atmospheric pressure - absolute pressure (the atmospheric pressure is generally 101325pa, and the ultimate absolute pressure of water ring vacuum pump is 3300pa; Limit absolute pressure of rotary vane vacuum pump (about 10Pa)
Vacuum
Theoretically, it means that there is no substance in the volume. In reality, there is no real vacuum. Generally, the pressure in the container lower than the normal atmospheric pressure (101325 PA) is called vacuum state.
Absolute vacuum and relative vacuum
Limit relative pressure
The relative pressure is how much lower the measured internal pressure is than the "atmospheric pressure". It shows that the actual value of system pressure is lower than the value of atmospheric pressure. Because the air inside the container is pumped, the internal pressure is always lower than the external pressure of the container. When expressed by relative pressure or gauge pressure, the value must be preceded by a negative sign, indicating that the internal pressure of the container is lower than the external pressure.
Ultimate absolute pressure
Absolute pressure is how much higher the measured internal pressure is than "theoretical vacuum (theoretical vacuum pressure value is 0Pa)". It compares the absolute vacuum pressure of the theoretical state. Due to the limitation of process, we can't pump the internal pressure to the value of absolute vacuum 0Pa in any case. The vacuum value pumped by the vacuum pump is higher than the theoretical vacuum value. Therefore, when expressed in absolute vacuum, there is no negative sign in front of the value.

vacuum pump in semiconductor remover application

Clarify 3 problems before vacuum measurement

First of all, we should have a more comprehensive understanding of all aspects of the tested object.
It mainly includes: the properties of the tested object, whether it is condensable gas or non condensable gas, whether it is single or mixed, inert gas or active gas or corrosive gas; Whether the air flow state is steady or instantaneous, whether it is uniform or non-uniform; Whether the temperature is isothermal or non isothermal, high temperature or low temperature; Whether there are special conditions such as magnetic field, electric field, vibration, impact, acceleration, charged particles, radiation, etc.
Secondly, according to the situation of the tested object and the research purpose, correctly select the vacuum gauge, and need to understand the principle, range and limitations of the selected vacuum gauge, so as to use the vacuum gauge correctly.
Third, we should understand the interaction between the vacuum gauge and the measured object.
The principles of various vacuum gauges are different, and its introduction may cause changes in some states of the measured object; At the same time, the gas in the measured object may also affect the vacuum gauge, change its performance and interfere with its work.
Moreover, when introducing the technical characteristics of vacuum measurement, fozhen has mentioned that the measurement accuracy of vacuum measurement is not high due to many influencing factors and difficult to control. Therefore, in order to carry out ideal vacuum measurement, we must fully understand the above-mentioned problems, so as not to cause greater errors or errors.

dry screw vacuum pump in EVA production process 

How should dry vacuum pump manufacturers choose?

When purchasing products, we should understand the quality of products, as well as the service and after-sales of brand manufacturers. Only in this way can we obtain more cost-effective services and products. Dry vacuum pump is a very common industrial equipment in the market, and it is widely used. So, how should dry vacuum pump manufacturers choose? What details should we pay attention to? Friends who want to know, let's have a look.
1、 Inspect the service system of the manufacturer
The manufacturer of each product is different in terms of service system. We should choose the manufacturer of dry vacuum pump, and we must choose the manufacturer with perfect service system and after-sales service. The reason for this choice is that manufacturers with after-sales service can provide high-quality products and services to protect the legitimate interests of businesses.
2、 Price of consulting products
When producing dry vacuum pumps, different manufacturers will choose different materials and use different technologies. Therefore, the production cost and price of products are different. When purchasing dry vacuum pump equipment, we should understand the price of the product and consult the function, service life and other aspects of the product. In this way, the product can be correctly evaluated.
3、 Understand the contents of the contract
Before signing the commodity contract with the dry vacuum pump manufacturer, we should confirm the contents of the contract. For example, product specification, model, quality, etc. At the same time, we should also understand the production period of products and relevant technical standards. In this way, we can get more professional services.
When selecting specific manufacturers, we should combine the above information. Regular and reliable dry vacuum pump manufacturers can ensure product quality and provide customers with high-quality after-sales service.

Roots-piston Vacuum Pump System Used in Vacuum Furnaces 

Regeneration of cryogenic vacuum pump

Unlike other gas transfer pumps, the cryogenic pump will be saturated in the gas capture process, so it is necessary to release the adsorbed captured gas to restore the capture capacity, which is called the regeneration process.
The regeneration of cryogenic vacuum pump actually includes partial regeneration (only releasing the gas adsorbed by the secondary cold plate) and full regeneration (releasing all the gas adsorbed by the cold plate). What this paper wants to understand is several ways of all regeneration of cryogenic pump.
1、 Natural temperature rise method. After turning off the refrigerator, use the heat of the pump wall to slowly heat up the vacuum pump. When the pressure in the vacuum pump rises to the effect of convective heat transfer, the heating rate accelerates and then reaches a stable heating value.
2、 Outgassing temperature rise method. After turning off the refrigerator, open the vent valve and put in clean and dry air to quickly heat up the cold plate of the low-temperature vacuum pump.
3、 Electric heating method. An electric heater is installed on the primary and secondary cold plate of the low-temperature vacuum pump. During regeneration, the low-temperature plate is heated rapidly by electric heating to shorten the regeneration time.
Among these regeneration methods, natural temperature rise is applicable to the vacuum system that removes a small amount of gas and is not continuous and long-term exhaust, which generally takes 5 ~ 6 hours. In applications requiring rapid regeneration, the latter two regeneration methods need to be adopted.
In the regeneration process of cryogenic vacuum pump, the released gas needs to be pumped out in time to prevent possible damage to the pump body or the glass tube shell of vacuum gauge, or even explosion. Because when the temperature rises to a certain temperature, the desorption speed of permanent gas is very fast, and the pressure in the pump body can rise to more than one atmospheric pressure within a few minutes.

Membrane separation vacuum pump unit selection for medical and petrochemical industries  

Difference between single-stage and bipolar rotary vane vacuum pumps

 

For the rotary vane vacuum pump, it must be divided into single-stage and two-stage. There is also a great difference in terms of single-stage and two-stage. For the oil seal rotary vane vacuum pump, we used to call the direct belt driven rotary vane vacuum pump, and directly connect the pump with the motor or connect it with a coupling, which is called the direct rotary vane vacuum pump. Here, we should pay attention to that for each pump, there are single-stage and two-stage. And in the single-stage pump, because the selected structural form and its parameters are different, the ultimate pressure of the pump and its purpose are also different. As far as the single-stage and bipolar rotary vane vacuum pumps are concerned, in terms of their common characteristics and their structure, they are actually relatively simple and convenient in terms of their use, that is, they can be started under atmospheric pressure, that is, they can be directly discharged into the atmosphere, and their eccentric mass is relatively small, In terms of its maintenance, it is also relatively simple. In terms of the structure of the pump itself, it is also improved. In this way, its reliability will be improved. In terms of the structure of the vacuum pump, in order to prevent oil return when the pump is stopped, a check valve that can automatically cut off the oil circuit will be set. However, in other terms, it will also be equipped with an air inlet channel stop valve. In addition, in order to automatically cut off the gas circuit to our pump port when the pump operates in the gas town and there is a sudden power failure, When it is in the state of vacuum rotary vane vacuum pump, in fact, it will be equipped with oil pump and control structure. For the two-stage rotary vane vacuum pump, it can also be widely used in refrigerators, air conditioners, light bulbs and fluorescent lamps. In addition, it can be used in bottle bladder production and electronics. In addition, it can be used in many industries such as metallurgy and medicine. Moreover, because the direct vacuum pump has no dust pollution caused by belt friction, its volume is relatively small and its weight is very light.

Dry screw vacuum pump for heat pipe industry

Present situation and Prospect of dry screw vacuum pump

At present, the development of various vacuum pumps is more and more 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, and the vacuum products have been updated. A large number of oil-free vacuum systems have been replaced by oil-free and clean vacuum systems.
Almost every large vacuum company abroad produces various types of dry vacuum pumps. Screw vacuum pump is a non-contact dry pump. It is an ideal pump in the early 1990s. It occupies the market with its advantages of wide pumping speed range, simple and compact structure, no friction of air extraction chamber components, long service life, low energy consumption and no oil pollution. However, most of its manufacturing technology is mastered by foreign countries. China is still in its infancy, and the market has great demand for dry pumps
At present, the development of various vacuum pumps is more and more 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, and the vacuum products have been updated. A large number of oil-free vacuum systems have been replaced by oil-free and clean vacuum systems.
Almost every large vacuum company abroad produces various types of dry vacuum pumps. Screw vacuum pump is a non-contact dry pump. It is an ideal pump in the early 1990s. It occupies the market with its advantages of wide pumping speed range, simple and compact structure, no friction of air extraction chamber components, long service life, low energy consumption and no oil pollution. However, most of its manufacturing technology is mastered by foreign countries. China is still in its infancy, and the market has great demand for dry pumps
Present situation of dry vacuum pump
Due to its superior performance, dry screw vacuum pump has become the preferred vacuum equipment in microelectronics, semiconductor, pharmaceutical, precision processing and other industries in Europe, America and Japan. On the basis of screw compressor, Japan has long developed the multi head rotor profile of vacuum pump and put it into the market. Several German vacuum equipment companies have also gradually developed equal pitch and variable pitch rotor profiles, and have done a lot of research on rotor and body cooling.
Key technical problems of screw pump:
Structure of dry screw pump:
The structure of screw vacuum pump is mainly composed of screw rotor, shell, cooling circulation and sealing materials. The transmission shaft is connected with the driving rotor and drives the driven rotor to rotate through the synchronous gear. A cooling water channel is opened on the shell to cool the temperature of the rotor and exhaust port. The synchronous gear and bearing are lubricated with oil. The interior of the bearing and housing is sealed by seals to achieve the effect of oil-free. The structure of dry screw vacuum pump is similar to that of oil-free screw compressor in sealing and lubrication. Generally, mechanical seals are used at the exhaust end of vacuum pumps, and double lip seals are commonly used at the inlet side. In terms of transmission mode, at present, the common is direct connected motor, which is connected with rotor by coupling, and very few are driven by belt or chain.
Due to no internal compression process, the exhaust temperature of equal pitch screw pump is very high (about 110 ℃). If the cooling effect is not good, it will cause deformation of rotor and casing and affect the sobbing effect. Therefore, cooling the casing is an essential link, and water cooling is a common method. Cooling water is supplied to the outer side of the bearing in the casing body to cool the casing and then the rotor. Laibao company applies water cooling inside the rotor to increase the service life of the rotor and achieve good cooling effect. However, this kind of structural design (two-stage type) requires certain technical and processing level support.
Sometimes the cooling effect cannot be achieved by water cooling, so the cooling gas (mostly nitrogen) is usually passed near the rotor at the exhaust end. Now the mainstream screw vacuum pump abroad adopts this method. This method has several advantages: it can cool the casing of the rotor and reduce the exhaust temperature; Second, when the gas contains particles, it can prevent particle deposition or chemical reaction from causing explosion.
Overview of dry vacuum pumps produced by domestic and foreign companies
(1) KDP and SDV series screw vacuum pumps of Taher company. Taher acquired Kenny vacuum. Kenny is a professional manufacturer of vacuum equipment in the United States with a long history. It is also in a world position in the manufacturing of screw vacuum pump. KDP series is a vacuum pump with equal pitch rotor, and SDV is a variable pitch screw pump. Both are water-cooling systems, and air cooling systems can be selected. SDV is an improvement based on KDP. The variable pitch screw pump can realize the internal compression of gas, reduce the exhaust temperature, and save 30% energy compared with the same pitch. Niflon coating is adopted on the rotor, i.e. the layer is Ni and the second layer is PFA. Even if the PFA is worn, the Ni layer can achieve corrosion protection, and kalrez perfluorinated rubber sealing ring is adopted. SDV series is the screw vacuum pump mainly promoted by Kenny company.
(2) The srewtine series screw oil-free compression vacuum pump officially launched by LeiBao company in Germany at the end of 2002 is a dry pump specially designed for industrial applications (non semiconductor applications). It is a new design and is specially used to solve the difficult vacuum problems in industrial applications. Such as dust, tar, etc. The pump also adopts variable pitch rotor with internal compression process. There is no internal valve in the pump cavity, so it has strong resistance to dust and tar. The screw of the pump adopts internal hollow cooling, which can reduce the rotor temperature and thermal deformation, so the service life of the screw is prolonged.
(3) Cobran series screw pump of Germany puxu company is a vacuum pump for manufacturing process, which is especially suitable for various process flows in chemical and pharmaceutical industries. Puxu is one of the suppliers of vacuum pumps, blowers and compressors in the world. The quality of vacuum pumps is high. Compared with other manufacturers, puxu has a high market share in Europe and the price is expensive.
(4) VSA / VSB series of Richler, Germany. VSA is an equal pitch rotor with good market evaluation and stable performance. VSB Series event pitch rotor design (non-linear tooth shape design), like other companies, changes the power consumption and exhaust temperature of the pump through internal compression. Without two-stage compression and intermediate cooling, a single stage can achieve very high vacuum. The sealing element is improved. The static sealing element is preferably PTFE or the sealing element added with PTFE. The dynamic sealing element uses double sealing lips on the suction side of the vacuum pump, and a simple sealing ring with gas overflow prevention is used on the exhaust side of the vacuum pump to prevent solid substances from entering the pump.
(5) Japanese manufacturers. Screw vacuum pumps are widely used in Japan, and are widely used in semiconductor and LCD industries. Yoshimura soldiers of Dahuang Co., Ltd. applied for patents on single head first-class screw rotors for a long time and made in-depth research on rotors. Hitachi also made research on screw pump in the early stage.
3. Research prospect:
The domestic research of dry screw vacuum pump is still in the initial stage, and many technical problems have not been solved. For example, the rotor coating anti-corrosion technology, reducing the temperature of the exhaust port and increasing the utilization rate of the rotor area are still very difficult. When extracting some active gas, due to the high exhaust temperature, it also needs to be considered in the design. When used in the occasion where the volume needs to be controlled, how to reduce noise should also become the research direction, However, its superior performance determines that it will dominate the vacuum equipment industry, just like the dominant position of screw compressor in the industry.

Dry Screw Vacuum Pumps Used In Fruit Freeze Drying Industry

What is the ambient temperature of the vacuum pump

 

What is the ambient temperature of the vacuum pump? Too high or too low temperature will affect the operation of the equipment and affect many operations of the equipment. Therefore, users should learn to adjust the temperature and always keep the equipment above a good temperature. So what is the appropriate ambient temperature to use it? 1. Gas analysis and partial pressure measurement under vacuum conditions are usually completed by dynamic mass spectrometer. If the medium to be transported contains solid particles, a filter screen shall be added at the pump inlet; If ferromagnetic particles are contained, a magnetic filter shall be added. 2. The ambient temperature of the vacuum pump in use shall be lower than 40, and the temperature rise of the motor shall not exceed 75. After 1000 hours of normal operation of the magnetic pump, remove the bearing and end face moving ring, check the wear, and replace the vulnerable parts that cannot be reused. For the medium easy to precipitate and crystallize, clean the conveying liquid immediately after use and discharge the liquid accumulated in the pump. The vacuum pump must always be clean. No other articles shall be placed on the vacuum pump, and the channels around the pump shall not be blocked. Always pay attention to the tightness of the V-belt and adjust it. Always pay attention to whether each pipe joint leaks and whether the pre vacuum in the box is reduced, otherwise it needs to be repaired in time; Always pay attention to whether the cooling water is unblocked. Start intermittently 4-6 times within 2S each time to overcome the large torque during startup. Here, we need to know the ambient temperature of the vacuum pump, and we must measure whether the ambient temperature meets the corresponding normal range before formal use. In addition to keeping the vacuum pump at a good temperature, we must also do a good job in heat dissipation.

Liquid Ring Vacuum Pump Used in Block Moulding Machine in EPS Production

Maintenance problems in practical application of vacuum pump

Vacuum pump is the main force of many science and technology, and provides necessary conditions for the operation of many laboratory application equipment. Unfortunately, if the pump is exposed to acid or organic chemical fumes for a long time, it will cause some practical maintenance problems. Especially for the oil sealed rotary vane pump, exposing the oil to chemical steam will lead to oil deterioration or decomposition, which will affect the function of the oil mist separator of the vacuum pump.
Many applications require a high degree of vacuum, so vane pumps are required. These high vacuum pumps are essential for installing the vacuum pump oil mist separator.
1: Read the instruction manual carefully
After purchasing the pump, carefully read the manual, check the operation precautions, select the appropriate vacuum pump oil according to the suggestions in the manual, and select the vacuum pump oil fume filter according to the pump model. The manual usually recommends the time of oil change.
2: Warm up the pump
Run the pump for 20-30 minutes before connecting it to the vacuum system. Consider installing manual valves to facilitate the preheating process.
3: Do not block the pump outlet
The pump outlet is blocked, which will cause the pump to stop working. In the worst case, overpressure in the pump may loosen the seal around the oil mirror glass, resulting in leakage and maintenance. Install the vacuum pump oil mist separator to make the air flow more stable.
4: The inlet cold trap is used to protect the pump from corrosive steam
The cold trap at the inlet can not only protect the pump from corrosive steam, but also reduce the steam load on the pump, so it can work more effectively. Ensure that the temperature of the solvent is low enough, such as using liquid nitrogen (for highly volatile solvents).
5: When handling condensable vapors, use gas ballasts
The air ballast of the vacuum pump uses air to push the condensate to the outlet through the pump. For applications with high steam load and corrosive gas, the mixing pump (diaphragm pump / rotating blade combination) will maintain the vacuum state of the oil storage tank and continuously distill steam and corrosive gas from the pump oil, so as to reduce corrosion and greatly prolong the service life of the pump. The oil change cycle also extends the replacement cycle of the vacuum pump oil mist separator.
6: Use an air inlet filter to protect the pump from particulate contamination
Use the air inlet filter to remove abrasive particles from the pump oil and rotating equipment. Reduce the pump oil pollution caused by impurities, and cooperate with the oil fume filter of the vacuum pump to effectively improve the performance of the vacuum pump.
7: Run the pump after use to remove the solvent from the oil
After completing the operation, you need to open the air ballast, close the air inlet and let the pump run for a few minutes. By operating the pump near the maximum vacuum but with good air circulation, many solvents dissolved in the oil can be removed, thereby reducing internal corrosion during shutdown.

Liquid Ring Vacuum Pump Used in Block Moulding Machine in EPS Production

Precautions for leakage detection of screw vacuum pump

 Leakage detection must be carried out before screw vacuum pump is put into operation. If the operation is not correct, the vacuum pump will be damaged. The following points shall be considered when detecting leakage:

First, it is necessary to find out whether the test piece can bear positive pressure and how much pressure it can bear, so as to determine whether the extraction leakage test method and the gas that can be filled with pressure can be used.
Before detecting the leakage of screw vacuum pump, the weld shall be carefully cleaned to remove welding slag, oil stain and dust.
The light at the leak detection part shall be sufficient, the bottom of the sink shall be dark, the water shall be clean and transparent, and there shall be no steam and fog on the water surface.
The test piece shall be inflated first and then put into water. Otherwise, if there is a large leak, water may enter the container under inspection and the small hole may be blocked by water. Before putting them into the water, please use the monitoring method to check whether there is a large leakage, and then put them into the water after eliminating the large leakage, otherwise it will affect the detection of small leakage.
When the screw vacuum pump specimen is placed in water, bubbles may appear on the surface of the specimen. If these bubbles are erased or punctured and the bubbles no longer appear, it can be judged that there is no leakage. Where bubbles are initially generated. If bubbles appear regularly and continuously, there will be leakage where bubbles are generated.
The inspected part shall be kept stable in the water and observed after the water surface is flat. The inspection position of screw vacuum pump shall be as close to the water surface as possible. If any leakage is found, mark it in time. If there is a large leak, check the small leak after repair.
In short, the screw vacuum pump can only be put into use after passing the leakage detection; Otherwise, unnecessary damage will be caused for future use.

Water Ring Vacuum Pump System Used in Automotive Semiconductor

Analysis on damage factors of dry screw vacuum pump

 1、 Analysis on the causes of corrosion on the rotor surface of screw pump the feed medium of vacuum pump contains sulfur dioxide and water. Sulfur dioxide combines with water to form sulfurous acid. Sulfurous acid has corrosive effect on metal. In order to prevent corrosion of rotor and pump cavity, Teflon layer is coated on the surface of rotor and pump cavity. Corrosion of rotor and pump chamber indicates that the layer is damaged and sulfite has corroded to the pump chamber. 2、 Cause analysis of Teflon layer damage in rotor and pump chamber there may be three reasons for the damage of Teflon layer on the surface of rotor and pump chamber: first, solid particles enter the pump chamber and cause coating damage. Second, chemicals form colloid on the pump cavity and rotor

1、 Cause analysis of surface corrosion of screw pump rotor
The feed medium of the vacuum pump contains sulfur dioxide and water. Sulfur dioxide combines with water to form sulfurous acid. Sulfurous acid has a corrosive effect on metals. In order to prevent corrosion of rotor and pump cavity, Teflon layer is coated on the surface of rotor and pump cavity. Corrosion of rotor and pump chamber indicates that the layer is damaged and sulfite has corroded to the pump chamber.
2、 Failure analysis of Teflon layer in rotor and pump chamber
There may be three reasons for the surface layer damage of rotor and pump chamber:
First, solid particles enter the pump cavity, which causes coating damage.
Second, chemicals form colloid on the pump cavity and rotor, which carbonizes and hardens and destroys the coating of rotor and pump cavity.
Third, other reasons.
1. Failure analysis of solid particles
Check the pump inlet equipment and pipeline, and no free moving solid particles such as metal fragments and iron chips are found.
2. Analysis of colloidal carbon deposition failure
Fig. 1 is a picture of the attachment on the inner wall of the pump inlet pipe. The substance is dark brown. After analysis, it contains iron, carbon and oxygen. It is a polymeric substance such as butadiene and sulfolane, which is bonded to the inner wall of the pipe. If the substance adheres to the pump cavity and rotor surface, it is easy to carbonize and harden, thus damaging the rotor surface layer.
3. Process factor analysis
The gas phase outlet pressure of the vacuum pump is 80kPa (a), which is negative pressure, while the liquid phase outlet of the pump is normal pressure. Under normal circumstances, the liquid at the pump outlet cannot normally enter the underground liquid tank, resulting in backflow, resulting in the accumulation of liquid substances at the pump outlet. These liquid substances contain sulfurous acid, and the accumulation of sulfurous acid at the pump outlet forms impact corrosion to the vacuum pump, It should be said that the backflow of liquid at the pump outlet is the main reason for the corrosion of pump rotor and pump cavity.

Dry screw vacuum pump for yarn steaming machine

What should be paid attention to when using roots vacuum unit?

Now our industries are some modern industries, and pump products are an indispensable part of some enterprises. There are many kinds of pump products, and their functions are relatively comprehensive. Roots vacuum pump unit is a widely used equipment in industry. Next, let me introduce the misunderstandings that should be paid attention to when using roots vacuum pump unit.

1. The roots vacuum unit must be equipped with a front stage pump, and the roots pump cannot be used alone.
2. When selecting roots vacuum unit, we should pay attention to the sealing mode of vulnerable parts of roots pump. The mode of mechanical sealing can effectively improve the working efficiency of roots pump. If the sealing mode of roots pump is shaft sleeve sealing, the working efficiency will be greatly reduced. We need to pay special attention when selecting roots pump.
3. Roots vacuum machine is mostly used in Roots vacuum unit. Its function is to improve the pumping speed and the vacuum degree of the front stage pump. The roots pump shall be equipped with bypass valve in the configuration connected with the front stage pump, which can effectively protect the roots pump. If the pumping of the front stage pump is unstable or other factors lead to abnormal operation of the whole unit, the roots pump with bypass valve will protect the roots pump at this time, so as to prolong the service life of the whole vacuum unit.
4. If the vacuum degree of Roots vacuum pump is reduced during use, it is necessary to check whether the clearance between roots pump rotors has changed. If the rotor clearance of roots pump becomes larger, the roots pump needs to be replaced, because this kind of Roots vacuum machine does not make static and dynamic balance for Roots pump rotors during production and processing, Or it is sealed with shaft sleeve.

Milking machine selection vacuum pump