Development and Application of Oilless Vortex Vacuum Pump Technology

I. Introduction The concept of vortex has been quite long ago. At the beginning of the 20th century, the world already had the patent of vortex technology. However, due to the technical limitations of the time, eddy institutions can not be manufactured, the concept of vortex also be forgotten. The scroll mechanism was reintroduced in 1973 and the first model agency was created, making the practical application of this technology possible. Whirlpool mechanism of high reliability, smooth operation, low noise, energy saving potential and great advantages immediately caused the refrigerator industry attention and urgent needs, greatly favored by the industry leader, was quickly put into industrial applications. Scroll compressor technology and products of well-known companies such as Trance, Hitachi and Copland have led the tide of practical application of vortex technology in the world, which has led to technological progress and product upgrading in many industries such as refrigerators and air conditioners. Today, the vortex technology has been promoted to the vacuum pump manufacturing industry from the initial application in the compressor industry, and has realized the practical application of the vortex cleaning vacuum obtaining technology without any oil, with a smoother operation, lower noise and more energy saving. People use the vortex concepts and principles to create a single-stage, two-stage oil-free vortex vacuum pump products that have no pollution to vacuum application equipment and environment, and are superior to conventional oil pumps in terms of pumping speed, life expectancy and energy consumption. In the early 90s of last century, the world's first scroll vacuum pump to market, scroll technology thus began as a new type of vacuum access technology is being promoted around the world. So far, the world's vortex vacuum pump manufacturer focused on the United States, Japan and Europe, Japan's Anestta, the United States Varian, Germany's Busch as the representative. Products include from 0.25L / S to 10L / S series of products, some 15L / S or greater pumping capacity of the product is also the pilot phase. Second, oil-free scroll vacuum pump characteristics and application areas Clean vacuum environment has always been the ideal vacuum environment pursued by scientists and business people.From the beginning to create a vacuum environment, people try to use different means to achieve the effect of cleaning the vacuum.Up to now, clean vacuum access equipment has been developed to the condensate pump, live Race pump, claw pump, scroll pump and diaphragm pump, etc. Among the existing oil-free vacuum pumps, oil-less scroll vacuum pumps have the following characteristics compared with other types of oil-free vacuum pumps: ①. No oil, no friction - no vacuum chamber oil, non-contact, no wear and tear, does not produce particulate dust pollution, access to clean vacuum; ② large amount of pumping - double scroll, the structure and single-stage pump diameter compared to the same diameter of 2 times, to save energy; ③ pumping efficiency - with 3-4 pumping unit, the pressure is small; between the atmosphere and the vacuum sealed by the O-ring, low leakage; ④ non-contact, good balance, little torque, low noise, small vibration; ⑤. The structure is simple and compact, the same size, small radius of motion, stable operation; ⑥. Small size, easy maintenance, low maintenance costs; ⑦. Using air cooling, no water cooling. The current application of oil-free scroll vacuum pump is: ①. Semiconductor industry - film preparation equipment, semiconductor device packaging equipment; ②. Scientific Instruments Industry - Synchrotron radiation beam line, electron microscope, analysis and testing equipment; ③. Machinery and equipment industry - material preparation equipment, vacuum testing, material purification equipment; ④. Chemical Industry ⑤. Medical Equipment - Dental Instruments, Dialysis Machines, Biologics and Pharmaceuticals Preparation; ⑥. Packaging industry - food, medicine, biological products and other packaging equipment. Third, oil-free vortex vacuum pump working principle, technical indicators and compared with the ordinary pump Oil-free scroll vacuum pump consists of five components: ①. Vortex scroll pay with the base; ②. Crankshaft ③. Gasket ④. Anti-rotation mechanism; ⑤. Motor. The non-oil scroll vortex scroll is a scroll-like disk structure formed by one or more involute helices with one end connected to a plane. A fixed scroll and an orbiting scroll interact with each other and are assembled 180 by the anti-rotation mechanism. Phase difference, so combined with the composition of a pair of scroll to pay the oilless scroll vacuum pump constitutes the basic pumping mechanism. The fixed scroll and the movable scroll are in contact with each other on several straight lines (ie, several points on the cross-section vortex) to form symmetrical pairs of crescent cavities. The orbiting scroll is driven by the crankshaft to rotate around the static Scroll scroll center movement, the fixed scroll and the movable scroll contact point along the vortex curved surface to achieve inspiration, compression and exhaust. For example, in a two-stage oil-free scroll vacuum pump, there are two directions corresponding to the fixed scroll, an orbiting scroll between two scroll. Dynamic and fixed vortex scroll relative movement of the volume of the crescent-shaped vacuum chamber so that the gas suction from the suction port, the exhaust port discharge to complete the suction, compression, exhaust cycle. Each revolution of the crankshaft, there is a new group of crescent cavities, so the non-oil vortex vacuum pump suction, compression, exhaust cycle to nearly 1500 rev / min frequency is continuously repeated, the evacuation of gas to form inclusive and mandatory delivery . As we all know, oil-free scroll vacuum pump (Oil free scrloo vacuum pump) compared with the ordinary oil vacuum pump has significant features. The following rotary vane vacuum pump to illustrate the difference: Table 1 oil-free vortex vacuum pump with ordinary rotary vane vacuum pump technical indicators of the contrast Technical indicators Rotary chip oil vacuum pump Vortex oil-free vacuum pump Pumping speed (1 / s) 2.0, 4.0, 8.0 2.0, 4.4, 8.7 Ultimate vacuum (pa) 0.6 1.0 Service life (h) 40000 40000 Overhaul interval (h) 8000 8000 Cooling medium oil air Noise (dB) 75 60 Quality (kg) 70 41 Motor Phase 3/1 1 Voltage (V) 220/380 220 Power (KW) 1.1 0.6 Number of revolutions (r / min) 1400 1437 Fourth, the advantages of oil-free scroll vacuum pump and its problems to the user 1. Oil-free vortex vacuum pump superior performance The main advantages of oil-free scroll vacuum pump include: ①. The sealing is good, there is no direct connection to the mechanical pump suction, exhaust cavity leakage channels, easy to seal, easy to reach a higher degree of vacuum. ②. Slewing radius is small, the relative sliding speed of the moving scroll is only about 1/7 of the rotary vane vacuum pump, the dynamic seal between the moving scroll and the fixed scroll is relatively easy, which will help prolong the service life of the pump. ③ compression process will be more slow, there are 2 or 3 compression process at the same time, the compression chamber relative to the crankshaft symmetry, so that the smooth operation of the pump, the driving torque and gas shock fluctuations small, so that the pump noise and vibration reduction. In short, the non-oil vortex vacuum pump has the advantages of simple structure, high compression ratio, stable pumping speed over a wide pressure range, wide working pressure range, small clearance between the movable scroll and small leakage, The change in volume is continuous, so the change of the driving torque is small, the change of the power is small, the vibration noise is low, the reliability is high. This is not available with other types of dry vacuum pumps. 2. Oil-free vortex vacuum pump to solve the basis of pollution and vibration, common problems As the ordinary rotary vane pump leakage, noise, oil pollution, high energy consumption and vibration and other issues to users adversely affected, such as the biological products industry and the semiconductor industry, oil vapor pollution and process system to return the oil problem. Vacuum coating equipment coating process, coating under 20 ~ 40Pa vacuum conditions, if the application of ordinary rotary vane vacuum pump as a front-stage vacuum pump coating equipment will cause pollution, affecting the quality of the film. There is a noticeable difference in yield between semiconductors used in the manufacturing process of pumps and in pump applications, and the resulting oil mist vapors also pollute the environment. The scientific instrumentation industry, especially in the analytical instrumentation industry, Adverse effect Large synchrotron radiation beam line using oil-free scroll vacuum pump as a front-stage vacuum pump role is quite obvious. In addition, oil-free vortex vacuum pump to eliminate the ordinary oil pump to the user's environmental pollution and annoyance. The use of existing oil-free scroll vacuum pump users also demonstrates the superiority and reliability of such pumps. 3. Oil-free vortex vacuum pump to reduce system manufacturing and operating costs In order to prevent common rotary vane oil vacuum pump back to the oil pollution, you need to add cold trap in the extraction system to capture the oil molecules; system operation process also need regular cleaning degreasing; and some need regular replacement of vacuum pump oil. The first part of the vortex vacuum pump need to add cold trap trapping mechanism, the second does not need to replace the vacuum pump oil, the third vibration smaller, more stable operation, the fourth energy consumption is reduced, the fifth weight lighter, the sixth breakthrough Pump limits the use of. These advantages make the non-oil vortex vacuum pump rotary vane vacuum pump to become a replacement product. Five, oil-free scroll vacuum pump structure The main components of the oil-free scroll vacuum pump to pay \ Crankshaft and gaskets. The pump pumping - compression - exhaust mechanism is moving, the fixed scroll without touching each other, according to * move, The fixed scroll rotates relative to form a suction chamber and a compression chamber, and the evacuated gas is discharged to continuously perform the processes of suction, compression and exhaust. In full consideration of the heat exchange process in the case of exhaust, minimize the dynamic and static scroll asked radial and axial clearance, can increase the pumping speed and ultimate vacuum. Gas-free vortex vacuum pump for the existence of the operation of water and impurities in the operation process is easy to accumulate and bearing wear and tear of the weakness, filling valve is the necessary choice. There are two main structural improvements: ①. Aerated ballast valve to maintain the required value of the ultimate vacuum - intake pressure O.03MPa (G) the following flow rate lOL / min or less. ②. Bearings and seals on both sides sealed to effectively prevent bearing wear. In the design of oil-free scroll vacuum pump, the problems to be solved include: ①. Determination and Modification of the Line Equation of CAD Design of Scroll Pump, Initial Angle Correction and Motion Simulation ②. Vortex plate machining one by one processing accuracy, the size of the processing gap: pumping speed, the ultimate vacuum; ③. Scroll surface treatment eleven corrosion-resistant, lubrication, hardness, processing technology, surface uniformity; ④. Gasket material selection and processing - Gasket requires flexible, wear-resistant, does not produce particles. VI, the use of oil-free scroll vacuum pump 1. Safety Precautions Safety precautions before and during use include: Non-oil vortex vacuum pump extraction range (used to clean the net gas can not be pumping toxic, flammable, explosive, corrosive gases, chemicals, solvents and powders, etc.). Installation requirements (installed in the absence of flammable, explosive materials, shelter, no steam safety). Install on a level surface (dip less than 5). No dust, no iron filings, stones or blocks around. Be sure to ground safely. Be sure to install the emergency brake switch. Wiring should be done by a qualified electrician). In the appropriate working environment temperature (5 ~ 40 ℃) within the work. Correct installation (disconnect or check the power must be cut off, you can not put your fingers or other items into the pump air holes or cooling fins gap). Correct maintenance inspection (according to this manual requires regular inspection, the pump is thoroughly cooled before maintenance and inspection work; by professionals, can not transform the pump). 2. installation method Before installation, carefully check the following items: ①. Check that the packaging is in the correct orientation. ②. Check that the product is the order model. ③. Check to confirm no damage. ④. Remove pump inlet and outlet flanges when pump is running. If continuous flange work, will cause damage to the pump. Attention should be paid when installing ①. Install in a rain-proof, steam-free place to avoid the risk of electric shock; ②. Installed in a well-ventilated, isolated explosives, non-corrosive and flammable gases and other related objects Department. ③. Install in a solid, flat surface (dip less than 5.), the sun can not direct the Department. ④. In the provisions of the ambient temperature range (5-40 ℃) within the work. To install the vacuum chamber and the inlet connection cut-off valve and exhaust valve. These valves are used to prevent the debris accumulated in the pump from being drawn back into the vacuum chamber when the oilless scroll vacuum pump is switched on. Close the shut-off valve when switching the pump. The connection pipe must be clean. Hose connection is recommended so that pump vibrations do not reach the vacuum chamber. When connecting the exhaust pipe to pay attention to the length and size of the pipe. Proposed exhaust pipe length not exceeding 15 meters, diameter 25mm. Note that the exhaust pipe when the pump can not be blocked. Note that the exhaust pressure can not exceed atmospheric pressure. When connecting, first disconnect the power supply and connect it with a qualified electrician. The pump must provide external protection, such as 8L / s pump minimum circuit capacity of single-phase, 18A, maximum shunt current circuit breaker capacity of 15A. Be sure to install the recommended capacity of the circuit breaker in order to avoid burning the motor, wire and ground cross-sectional area must be more than 2mm2. Doing so may cause damage or fire. The wires connected to the motor terminals should be fitted with a suitable circular connector. Be sure to ground. Doing so may cause electric shock or personal injury. The delivery voltage is single phase, 220 volts. 3. Oil-free vortex vacuum pump operation - pumping dry gas Oil-free vortex vacuum pump in the first start or long time to reach the ultimate vacuum takes longer time. Should be in the state of closing the intake valve continuous exhaust 6-8 hours, open the intake valve every hour 2 to 3 times, each 3 to 5 seconds. If pump or high humidity gas (relative humidity> 60%), water vapor may remain in the pump to reduce the performance of the pump. Then close the stop valve between the pump and the system, start the pump, open the inlet valve into the atmosphere when the operation several times, each 3-5 seconds, you can pump the water vapor discharge. Pump work to remove the inlet flange and exhaust flange, otherwise it will damage the pump. Close the shut-off valve when the pump is started and closed, otherwise the accumulated debris in the pump will be drawn back into the vacuum chamber when the pump is switched on and off. Restart the pump, before starting to open the intake valve into the atmosphere 3-5 seconds, otherwise it will cause the pump temperature imbalance, resulting in pump failure. Start-up procedures for oil-free scroll vacuum pumps include: ①. Close the stop valve (in order to avoid the accumulation of pump debris will be pumped back to the vacuum chamber (with a leak valve open to open the leak valve)); ②. Turn on the pump switch ③. Open the shut-off valve (check to confirm the vacuum pump is turned on, use the leak valve to close the leak valve, vacuum chamber). Stop pump steps include: ①. Close the shut-off valve (to prevent accumulated debris in the pump from being drawn back into the vacuum chamber); ②. Turn off the pump switch. 4. Oil-free vortex vacuum pump operation - pumping steam (1) pumping attention Oil-free vortex vacuum pump maintenance standards are based on clean gas developed, different pumping standards. So pay attention to the following points: ①. Pumping water pump maintenance intervals must be shortened, because the water vapor temperature, the amount of removal, removal frequency and water vapor in the material composition of the pump have an impact. ② pumping steam, to work at the specified temperature, intake air temperature must be lower than 50 ℃. When the temperature of the evacuated gas is higher than 50 ° C, a cooler or cold trap should be installed on the connecting line between the oil-less scroll vacuum pump and the vacuum chamber to lower the temperature of the inlet air to less than 50 ° C. Air inlet temperatures above 50 ° C will damage oil-free vortex vacuum pumps. ③. Suction valve when pumping steam, oil-free vortex vacuum pump suction steam will cause water vapor condensation in the pump. Condensation of water vapor will cause the pump to reduce the ultimate vacuum, or cause damage to the pump. Gas town valve not only pumping steam, but also to maintain the ultimate vacuum. (2) gas ballast valve precautions The so-called gas valve and the concept of its role is very simple, that is, in the positive displacement vacuum pump to open a small hole on the chamber, fitted with a control valve. Open the control valve to start oil-free vortex vacuum pump, when the orbiting scroll rotates a certain position, the air is introduced into the compression chamber through the small hole to reduce the compression ratio, so that most of the water vapor will not condense, Gas is discharged outside the pump. This achieved the purpose of pumping steam. This valve is the gas valve town. Gas ballast valve precautions include: ① pumping steam, you must open the gas valve exhaust. If the gas ballast valve is closed, the vapor will accumulate in the pump, damaging the pump. ②. Pumping, you must open the gas valve in the state and then exhaust more than 1 hour, if pumping gas immediately after the closure of the gas valve, water vapor will accumulate in the pump, causing damage to the pump. ③. When filling the gas valve port with nitrogen or dry air, the pressure should be controlled at atmospheric pressure, the flow is less than lONL / min, high pressure will cause damage to the pump. ④. When the vacuum chamber is more than 60% humidity, - be sure to open the gas ballast valve. ⑤. Be sure to turn on and off the gas ballast valve before the pump is turned on and off, and do not close the gas ballast valve during pump work. Changing the working state of the gas ballast valve (on or off) during pump operation can damage the pump and cause personal injury. (3) pump operation when pumping steam Pumping, pump start-up steps include: ①. Close the shut-off valve (in order to avoid the pump will be stored in the pump when the debris will be pumped back to the vacuum chamber (with leak valve to open the leak valve)); ②. Open the gas valve (remove the plug, replace the gas filter can be); ③ open the pump switch; ④. Open the shut-off valve (check to confirm the vacuum pump is turned on, use the leak valve to close the leak valve, vacuum chamber). Pumping steam stop pump steps include: ①. Close the shut-off valve (to prevent the debris accumulated in the pump from being drawn back into the vacuum chamber; ②. Turn off the pump switch ③. Close the gas ballast valve (gas ballast valve work, remove the gas filter, gently wrench with a screwdriver plug). 5. Oil-free scroll vacuum pump inspection and maintenance (1) inspection and maintenance precautions ①. Oil-free vortex vacuum pump In order to prevent the deposition of debris in the pump, pumping the atmosphere several times a day, each 3 to 5 seconds. ②. Pay attention to high temperature, after the pump is cooled enough, check and maintain again. Repair immediately after stopping the pump may cause burns. ③. Be sure to cut off the power before checking and maintaining. Failure to do so may result in electric shock or injury from rotating objects. ④. If the installation and working conditions are poor, the working environment temperature exceeds the required, shorten the maintenance interval. Ambient temperature is the main cause of pump failure. Standard maintenance interval is based on the ambient temperature of 5 ~ 40 ℃, the average annual temperature of 25 ℃ formulated. (2) inspection and maintenance of the main points part Checkpoint and attention point Check the time interval Bearing Abnormal noise Check every day New replacement bearing 8000 hours Seals such as gaskets, o-rings Newly updated seals 8000 hours 6. Troubleshooting and troubleshooting Over the past few years users in the use of oil-free scroll vacuum pump, one after another found a variety of problems, but also summed up the way to solve the problem. To sum up, nothing more than the following. If there is a fault, you can refer to the following table to exclude it. If you can not solve the problem, you can contact the seller and the seller of the pump. At the same time I welcome the user to put forward the use of the problem, in order to facilitate the further improvement of oil-free scroll vacuum pump. Seven, concluding remark Domestic manufacturing processes represented by the semiconductor and electronics industries and the scientific research and analytical testing industry urgently require clean, oil-free vacuum environments, but clean vacuum access equipment such as condensation pumps, column pumps, claw pumps, scroll pumps and Diaphragm pumps are currently not formed * Advanced batch of domestic products. Imported oil-free scroll vacuum pump as a new product, due to the price mentioned earlier in this article, market development and user awareness and other reasons, did not form a virtuous circle. In this way, on the one hand, the urgent market demand, on the other hand, there is no suitable product in terms of both price and technology, resulting in a huge market gap. There is no doubt affordable, performance can be * non-oil vortex vacuum pump will become the mainstream of products suitable for the Chinese market, to develop vortex oil-free vacuum pump is imperative. The development of the Vortex Series and other oil-free vacuum pumps that meet the requirements of the Chinese market and their testing techniques have also become an opportunity for the vacuum industry in China to further develop. Oil-free scroll vacuum pump fault diagnosis table phenomenon the reason Solution Pump stopped Switch is abnormal Overhaul Sideline loose, short-term Overhaul Voltage drop Check the cable length and size Motor is abnormal Overhaul Pump is abnormal Overhaul Do not go to the ultimate vacuum Flange mouth scratched Contact your local dealer for repair Pipe is blocked Heat degassing or replace the pipe Pipeline leak Check the pipeline even tight Draw in water or solvent Vent the air inlet for a few minutes and then close the air intake for about 24 hours O-ring breakage replace Gas valve plug race Clean the gas filter or replace it Abnormal noise, vibration Loose connector Tight connection Pump is not flat Level the foundation Foreign matter into the pump Overhaul Exhaust valve failure Overhaul Motor failure Overhaul Bearing damaged Contact your local dealer for bearing change Pumping port blocked Contact your local dealer for repair In order to solve the basic and common problems existing in scientific research, new materials, and semiconductor industries in our country, experts in the industry have continuously introduced the technology of vortex oil-free vacuum pump and its development status in recent years. Foreign vortex oil-free Vacuum pump manufacturers and agents on the Chinese market to make its sales in the Chinese market is growing year by year. Relevant domestic enterprises in the vacuum industry also carried out the basic, applied research and small-scale trial production of oil-free vortex vacuum pump at different stages of exploration, but due to technical basis, incentive mechanisms, research and development tools, capital investment constraints, research and development work is not very fast . Product quality, stability and reliability, as well as technology promotion and market development planning, principles, tools, etc. are also problems. Therefore, non-oil vortex vacuum pump next step industrialization of technology research and development and market development is an enterprise must solve two major problems. With the development of means, capital investment, market development to solve the problem, oil-free scroll vacuum pump will open the market, thereby enhancing the vacuum access to the industry's technical level. Successful oil-free scroll vacuum pump product development and market development model will also be other clean vacuum access equipment such as condensate pump, plunger pump, claw pump and diaphragm pumps provide an effective reference. Technical indicators Rotary chip oil vacuum pump Vortex oil-free vacuum pump Pumping speed (1 / s) 2.0, 4.0, 8.0 2.0, 4.4, 8.7 Ultimate vacuum (pa) 0.6 1.0 Service life (h) 40000 40000 Overhaul interval (h) 8000 8000 Cooling medium oil air Noise (dB) 75 60 Quality (kg) 70 41 Motor Phase 3/1 1 Voltage (V) 220/380 220 Power (KW) 1.1 0.6 Number of revolutions (r / min) 1400 1437 part Checkpoint and attention point Check the time interval Bearing Abnormal noise Check every day New replacement bearing 8000 hours Seals such as gaskets, o-rings Newly updated seals 8000 hours phenomenon the reason Solution Pump stopped Switch is abnormal Overhaul Sideline loose, short-term Overhaul Voltage drop Check the cable length and size Motor is abnormal Overhaul Pump is abnormal Overhaul Do not go to the ultimate vacuum Flange mouth scratched Contact your local dealer for repair Pipe is blocked Heat degassing or replace the pipe Pipeline leak Check the pipeline even tight Draw in water or solvent Vent the air inlet for a few minutes and then close the air intake for about 24 hours O-ring breakage replace Gas valve plug race Clean the gas filter or replace it Abnormal noise, vibration Loose connector Tight connection Pump is not flat Level the foundation Foreign matter into the pump Overhaul Exhaust valve failure Overhaul Motor failure Overhaul Bearing damaged Contact your local dealer for bearing change Pumping port blocked Contact your local dealer for repair

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