What is the oil diffusion pump, oil diffusion pump works

Vacuum oil diffusion pump system is to carry through the high-speed steam jet exhaust gas in order to achieve the purpose, it is used for high vacuum work area, the working pressure range of 10-2 ~ 10-6pa. Oil vapor from the umbrella-shaped nozzle (nozzle, such as Class I) ejected at supersonic speeds, gradually increasing its speed, pressure and density decreases. </ P>
</ p>
</ p>
1, oil diffusion pump Overview: </ p>
oil diffusion pump works is similar to water vapor jet pump also rely on high-speed steam jet to carry the gas to achieve the purpose of vacuum, so there will be water vapor jet pump similar characteristics. The point is not the same as working in high vacuum diffusion pump region is mainly for high vacuum equipment. The working pressure range of 10-2 ~ 10-6pa. Widely used in vacuum smelting, vacuum coating, space simulation test is not sensitive to oil pollution and some of the vacuum system. </ P>
2, oil diffusion pump works with the structure: </ p>
umbrella when the oil vapor from the nozzle (nozzle, such as Class I) to supersonic jet out, its speed faster and faster, slowly reduce the pressure and density, jet stream above the pumped gas A steam jet to the density difference due to the diffusion was carried to the water jet pump wall at B, at B, most of the work of steam condensing into droplets along the wall-flow pump is recycled back to the pan, and was pumping gas at B accumulation, compression, and finally carried away by lower-level jet, so that you can progressively compressed, and finally pulled out before the pump. The pumping speed characteristic curve as shown. </ P>
3, oil diffusion pump development process: </ p>
History In 1915, German physicist W. cover may give the diffusion pump of his research report. In 1916, Americans made pump wall I. Langmuir condensation pump with a cooling system. These pumps with mercury vapor as the working medium, and can end up 10-5 Pa vacuum. In 1928, the British CD Boer Qi found a high boiling point of oil derivatives. In 1936, CD Hickman, who made of artificial synthetic oil. Both the oil in the saturated vapor pressure at room temperature is very low, thus replacing the mercury diffusion pump as working fluid. Since then, oil diffusion pump vacuum in the field of high industrial production and scientific experiment on the increasingly common use, and laid the basis for high vacuum technology. 1960s, oil diffusion pump has a new change. The main improvements are: ① put the gas pump materials using small stainless steel. ② The low vapor pressure, good thermal stability, such as polyphenylene ether and silicone oil as the working fluid pump. ③ change the structure of the new oil diffusion pump in the pump inlet flange and the constant increase of the pump, but sub-dimensions conditions, prominent in the lower flange of the pump chamber to expand cross-section, the pumping rate can be increased 20 to 40%. If the installation of a proliferation of large-diameter nozzle and liquid nitrogen cooling of large diameter gear oil cap, and so on. The pump may have usually pump (the absence of expanding cross-section of the pump cavity pump) pumping speed, and more thoroughly overcome the pump oil and get back less than 10-8 Pa clean high altitude. Therefore, the oil diffusion pump in ultra-high vacuum cleaner industrial production and scientific experiment has achieved an important position. </ P>

4, the structure and diffusion pump works </ p>
mainly by the diffusion pump oil pump, diffusion nozzle, steam pipe, pan, heater, diffuser, spray nozzles and cooling system other components (see Figure). When the oil diffusion pump with a pump before the pre-pumped vacuum of less than 1 Pa, the pan to start heating. Boiling speed of the steam nozzle flow, thermal motion of gas molecules spread to the vapor stream, and the directional movement of the oil vapor molecules collide. Gas molecules therefore have momentum, and oil vapor molecules have the same directional movement direction of the flow. To the previous level, the oil vapor is condensed to release gas molecules, he incurs pulled out before the pump suction to achieve the purpose. </ P>
</ p>
</ p>
vacuum pump oil directly affects the vapor pressure of the vacuum pump performance. But the oil diffusion pump oil pump used in any, are the vapor pressure of different multi-component mixtures. Therefore, to improve the oil diffusion pump and vacuum pumping performance of the pump in the work itself but also to pump oil for fractionation and purification. Fractionation purpose is to make high vapor pressure of the oil component is not working nozzle into high vacuum (high vacuum side of the nozzle); purification purpose is to enable a high vapor pressure components of the oil in the course of their work constantly for the first stage of the extraction pump, the vacuum oil becoming more and more pure. </ P>
cable trays manufacturers, cable tray sizing, cable basket
pump oil pump oil fractionation is the use of evaporation of each component at different temperatures, so that they were in a different area of ??the boiler evaporation. When the work flow reflux condensation of pump oil pump with insulating cover part of the wall, the oil that has been pre-heated, then flow around the pan, the bottom ring heater, light distillate oil will reach the evaporation temperature in the outer vacuum evaporation and the work of the nozzle into the low - near the pre-pump nozzles; not evaporate some of the light distillates is because a small proportion compared with other distillates and oil floating to the surface. As the outer tube of the steam limit this part of the distillate into a low-vacuum evaporation of the work after the nozzle. Heavy fractions of oil vapor in the outer tube has not reached due to the evaporation temperature without evaporation, so from the gap between the outer flow by the bottom center of the pan evaporation, the nozzle into the high vacuum work. Light and heavy distillate oil supply lanes so low vacuum steam nozzle and the work of this high-vacuum work a process called fractionation nozzle. Spray nozzle from the previous level of oil vapors are not adequately cooled, light distillate vapor condensation were not fully pump before extraction. This cycle of work, pumping in more and less on light distillate, heavy distillate thus increasing the proportion of the pump oil will gradually become pure. This process is called purification. Pump oil fractionation and purification, to improve the ultimate vacuum pump has an important role. </ P>
5, diffusion pump oil </ p>
pump structure in a certain context and no leaks, oil diffusion pump vacuum pumping characteristics and limits of the main oil pump is to look at the performance. Many different types of pump oil, table types and characteristics of the main oil pump. </ P>
</ p>
</ p>
diffusion pump when the oil is heated furnace to produce oil vapor along the diversion pipe to the following spray nozzle through the umbrella. Because the mechanical pump nozzle out there to provide the vacuum (Pa), it is oil steam flow can be emitted a long distance, constitute a direction to the outlet of the jet. Finally, the jet hit the wall of the cooling water pump cooling liquid flows back to evaporator condensate, ie by evaporation of the oil jet exhaust condenses repeat loop to achieve. From the inlet into the pump when the gas molecules into vapor stream downward momentum will be flying down. As the jet with high velocity (about 200m / s), high vapor density, molecular weight and diffusion pump oil (300 to 500), it can effectively take away the gas molecules. Gas molecules were taken to the exit and then pumped by the mechanical pump. </ P>
6, oil diffusion pump maintenance and repair </ p>
(1) oil diffusion pump to be installed vertically, so that the pump pumps the core components in normal working condition. The rubber seal should be sealed and reliable. </ P>
(2) oil diffusion pump cooling water before heating to ensure smooth flow of the pump at about 1 Pa vacuum can only be heated. </ P>
(3) oil diffusion pump to stop working, the pump into the atmosphere should be avoided in order to prolong life and reduce oil pump oil pump suction, the pump should be prohibited in particular not just stop working on the cooling into the atmosphere to avoid pump oil oxidation. </ P>
(4) oil diffusion pump long-term storage, preferably pumped into the vacuum to prevent pump oil contamination and corrosion of various parts, and should be blowing water jacket cooling water and the remainder water. </ P>
(5) has been pumping gas should be dry and free from corrosion, dust-free gas state at room temperature. </ P>
(6) pump performance of a sudden deterioration of normal working hours, the heater should be checked whether the short circuit, open circuit, and three-phase current balance. </ P>
(7) in long-term work, the gradual deterioration of pump performance, you should check whether the reduction or oxidation of oil in order to add new ones after drying oil or clean oil. </ P>
(8) a loading and unloading, if the performance can not be regarded, we must check whether the seal is reliable or improper assembly. </ P>
(9) in operation, should pay attention to the first stage diffusion pump mechanical pump is working properly, the limits of the general mechanical pump pressure should be pre-pump pressure than an order of magnitude lower than when the mechanical pump performance deterioration after the direct impact on the oil diffusion pump to work properly. </ P>
(10) for use with the pump pull the core application form for small and medium spinning pump, gently tighten the first stage nozzle cap should be against the weight of the pump core deformation. </ P>
diffusion pump look like </ p>