High vacuum system pumping

One of the fundamental considerations in planning a high vacuum system is the time required to pump the vessel to a given pressure. The scale of this moment usually ranges from a few minutes to a few hours. However, in some cases, the pumping time may be seconds or days. It is very difficult to estimate the connection between time and pressure by theoretical or experimental methods, because the outgassing rate (outgassing or virtual leakage) on the inner and outer surface of the container can not be recognized, but the time and pressure of air extraction are related to the rate of outgassing. 

The outgassing of the given data depends on the temperature, the surface finish, the exposure to various atmospheres prior to this, and the cleaning method. When the outgassing is significant, even an approximate estimation of the exhaust time may be very difficult. The planner can estimate the pressure time curve from atmospheric pressure to about 10-2 Torr by using a connection equation suitable for higher pressure. According to the steady state (long time) outgassing data and the characteristics of the pumping equipment, the ultimate (limit) pressure can sometimes be estimated. The most interesting region is from 10-2 torr to the limit pressure.

Water Ring Vacuum Pump

Dry Scroll Vacuum Pump

industrial vacuum pumps,vacuum furnaces

Water ring vacuum pump in chemical fertilizer operation

Chemical fertilizer industry has a decisive effect on China's agricultural development, especially the production of phosphate fertilizer is an industry supported by the key points in the micro regulation and control of national economy in China. Therefore, large and super large water ring vacuum pumps have also been used here. For example, a phosphate fertilizer enterprise in Yunnan Province added three extra large water ring pumps with pumping capacity of 300m3 / min after one transformation. 

In addition, there are many phosphate fertilizer enterprises that still need to have greater ability to pump air when the absolute pressure is 80 ~ 100hPa. However, the vacuum degree of a single water ring vacuum pump is 3300 PA, which can not meet the process requirements. However, if an atmospheric injector is added in front of the water ring pump, the vacuum degree will get certain progress and have common advantages.

It was found in the telephone consultation of many chemical fertilizer enterprises that the reciprocating vacuum pump they used before was gradually screened out because of the large number of vulnerable parts and high noise. The double-stage water ring vacuum pump was replaced by the double-stage water ring vacuum pump, which has achieved good results. According to the practical experience, the double-stage water ring vacuum pump will be used more and more widely in this profession.


CL Sereis Cone Liquid Ring Vacuum Pump

Roots Blowers

Roots Vacuum Pump 

Principle of pumping liquid by water ring pump

When pumping liquid, the process of suction is the same as that of gas. Because the speed of the sickle increases on the left side of the pump. 

According to Bernoulli's equation, when the speed increases, the pressure will decrease. When the liquid continues to move forward and flows to connect with the pressure outlet, the pressure will suddenly increase. The result of pressure increase makes the liquid passing through the pressure outlet be restrained and slow down. The sudden increase of pressure and deceleration will bring huge hydraulic loss. Therefore, the power of water ring pump in pumping liquid is very low (compared with pumping air) The power should not exceed 15 ~ 20%, because of the huge hydraulic loss and the "water conveyor effect" (when the liquid flows to the pressure outlet area, the liquid flows from the place with large radius to the place with small radius, and the liquid transfers its own energy to the impeller, just like the water conveyor), the lift is much smaller in practice. The head of water ring pump is smaller than that of centrifugal pump of the same scale.

Vacuum System Of Heat Exchange Unit

Vacuum Pump In Vacuum Extruder System

Liquid Ring Vacuum Pump In Beekeeping Tools 

Classification of water cooled roots vacuum pumps

(1) Roots vacuum pump with pressure stabilizing box: the rotor profile of this kind of roots pump has arc type, involute type and combined type. It has been described in detail before, but it will not be described here. The difference between this pump and dry roots pump is that it can be directly discharged into the atmosphere without the front stage pump and cooled with water instead of air cooling. A pressure stabilizing box is installed at the mouth of the pump shell, It has the effect of noise elimination and voltage stabilization, and is very convenient to use. 

(2) Roots vacuum pump with separators and silencers for direct discharge to the atmosphere: the structure, working principle and rotor profile of this roots vacuum pump are completely the same as those mentioned above. It is also a so-called wet roots vacuum pump with water cooling and direct discharge to the atmosphere with a front stage pump; The difference is that there is no pressure stabilizing box on the inlet of the pipeline, but a gas-water separator is installed on the pipeline of the inlet port, while a separation and muffler are installed on the pipeline of the entrance of * * to achieve the effect of gas water separation and noise elimination. Now, this kind of equipment is widely used in foreign countries.

Water Ring Vacuum Pump

Dry Scroll Vacuum Pump

industrial vacuum pumps,vacuum furnaces

Requirements of vacuum pump for smooth oil

In fact, the factors that affect the vacuum degree of vacuum pump are various, including sealing method, spare parts space, quality of materials, etc. This paper mainly explains the requirements of vacuum pump for smooth oil, because the quality of oil will also affect the vacuum degree of vacuum pump. 

(1) With appropriate viscosity: the viscosity of oil is too small, the smoothness is not satisfactory, the sealing performance is also poor, the viscosity is too high, the internal conflict is large, the rotor rolling is difficult, the kinetic energy consumption is increased, and the oil temperature is also increased. The increase of oil temperature will accelerate the oxidative degradation of oil, especially for rotary vane vacuum pump.

(2) Low full vapor pressure: the target of "vapor pressure" of oil is low, so it is not easy to transpiration under the working conditions of low pressure and high temperature in vacuum pump, so as to ensure the required vacuum degree.

(3) The oxidation stability is good, and it is not easy to oxidize and degenerate.

Generally, vacuum pump oil is selected for vacuum pump. At present, domestic vacuum pump oil only needs No.1, which is refined from natural crude oil. It has smooth and sealing effect in vacuum pump

CL Sereis Cone Liquid Ring Vacuum Pump

Roots Blowers

Roots Vacuum Pump

Reasonable selection of vacuum pump according to metallurgical gas quantity

The air source of vacuum metallurgical equipment in cold furnace pre pumping and hot state exercise is: 1) the atmosphere in the extracted space (related to the volume to be pumped); 2) the gas released during the process (including the generated and imported gas, which is related to the time, temperature, pressure and production process); 3) the surface gas released in the vacuum (related to the type of data, surface product, time, temperature and pressure, etc.) (4) gas leakage and infiltration (related to leakage rate of system components, welding quality of dynamic and static sealing components of equipment and structural materials), and (5) transpiration gas caused by data vapor pressure (related to temperature and pressure). 

In order to ensure the demand of metallurgical process, the planning of vacuum system is to select appropriate vacuum components such as pumps and valves according to the above-mentioned gas flow, and put forward reasonable placement scheme according to the process of gas extraction, so as to achieve the goal of removing the gas in the space to be evacuated, overcome the outgassing and leakage, and make the vacuum chamber always adhere to the required vacuum degree.

Roots Blower For Unloader

Roots Blower Used In Return Material Process

Roots Blower Of Lubricating Oil Selection 

Application and applicable temperature of high temperature pump

The flow passage parts of high temperature pump are made of stainless steel (304, 316L), which are widely used in petroleum, chemical, pharmaceutical, electroplating, environmental protection, water treatment, national defense and other departments. It is an ideal equipment for conveying flammable, explosive, toxic and precious liquids, and the best choice for creating a leak-free and pollution-free culture workshop. 

The normal applicable temperature of the high-temperature pump is less than 100 degrees. If high-temperature medium needs to be transported, it can be customized as high-temperature type, and the applicable temperature can be within 200 degrees. It can also be customized with insulation jacket to keep the high-temperature medium transported.

Water Ring Vacuum Pump

Dry Scroll Vacuum Pump

industrial vacuum pumps,vacuum furnaces