Serial number

Name

Application

Typical equipment

Vacuum degree (Torr)

Application examples

1

Simulation of aerospace environment

The orbital environment of aerospace is basically a vacuum environment.

The aircraft is in Before launch, a simulation test of the space environment must be conducted on the ground. Simulators of various sizes are vacuum devices. Including thermal vacuum simulation of satellites and spacecraft, material evaluation, thruster testing, manned simulation testing, etc. Comprehensive use of vacuum acquisition, testing, leak detection, technology and other technologies. Reproduce the space environment on the ground, evaluate the aircraft, discover and eliminate faults, and improve reliability.

Mechanical pump

Molecular pump

Cryogenic pump

10-2~10-14

Max Aerospace The container of the environmental simulation equipment is 1,000 cubic meters.

2

Accelerator technology

Charged particles are accelerated under accelerating field conditions.

The accelerating tube must be under high vacuum and ultra-high vacuum conditions from the ion source to the target chamber. To reduce the scattering loss of energy caused by the collision of charged particles with gas molecules. Therefore, the accelerator must have a vacuum system. There are special requirements in terms of vacuum acquisition, measurement, leak detection and other technologies.

Titanium pump

Cryogenic pump

10-11~10-12

The United States already has a 300-diameter stainless steel electron cyclotron< /p>

3

Controlled thermonuclear application technology

is a device that artificially controls thermonuclear reactions in an effective space. It is a high vacuum, high temperature technology and the combination of electromagnetic technology

Mechanical pump

Diffusion pump

Added cold trap

10-2~10-10

4

Vacuum conveying

Air and granular materials flow together under the suction action of vacuum. After arriving at a limited location, the materials and air are separated by a centrifuge and vacuum conveyed. , such as grain, coal powder, tobacco, cement, powdered food, etc.

The suction pressure of vacuum conveying is usually 300~500 Torr or 600~700 Torr. The former's mixing ratio (the ratio of the weight of the material being transported to the weight of the air) can reach 20, and the transportation distance can reach 400~500 meters. The conveying capacity reaches 200 tons/hour; the latter has a stick ratio of 3 to 5, a conveying distance of no more than 30 meters, a conveying capacity of 3 to 10 tons/hour, and the usual mixing ratio is 1 to 10. Vacuum conveying can also be used to convey certain liquid substances

Turbine blower

Water ring pump (water vapor jet pump)

300~700

(1) Vacuum transportation is used in the production of electrolytic lead

Send the lead water in the electrolytic tank

to the lead water bag ,

The vacuum pumps used are 2 sets

SZ~3 water ring pumps

(2) In chemical industry, tobacco,

It has also been used in the MSG industry

5

Vacuum filtration

The filter drum of the vacuum filter is within a 360-degree range Movement, the 180-degree interval is for vacuum suction and filtration, the 90-degree interval is for vacuum suction and drying, and the 90-degree interval is for inflatable discharge, so that continuous production can be carried out in the entire 360-degree interval.

Vacuum filtration can be used to obtain solid materials in mixed liquids or for filtration. The former is such as washing in mining or coal industries.

Production of rare metal "nickel" The process also uses

vacuum filtration, vacuum conveying and other processes

water ring pump

water vapor jet pump

50~100< /p>

(1) Alumina smelted from non-ferrous metals is extracted by vacuum filtration to extract AI(OH)3.

(2) A steel plant uses 5 Sz-3 water ring pumps equipped with vacuum filtration The machine is used to purify the sewage

and use it as circulating water after purification.

(3) A vacuum filter in a mineral processing plant is equipped with a 1500 kg/hour (100 Torr)

Water vapor jet pump has good use effect.

6

Vacuum drying

Vacuum drying usually refers to the removal of moisture or organic solvents from solid materials (also

liquid materials) For volatile components, the pressure in the gas phase is lower than 100 Torr. Especially when the pressure is lower than 10 Torr, vacuum will have a significant impact on the drying process. Vacuum drying It is characterized by a high drying speed at a lower temperature, so it is particularly suitable for materials that are not suitable for heating or materials that are difficult to dry. Generally, appropriate latent heat of vaporization should be provided during the vacuum drying process.

Mechanical pump

Water vapor jet pump

Several to dozens of Torr

In the electrical industry, the vacuum of insulated paper cables Drying, drying of slices produced in nylon and polyester in the synthetic fiber industry. Vacuum drying of dairy products, tea essence, meat, etc. in the food industry. It is widely used in other industries such as medicine, pesticides, dyes, etc.

7

Vacuum distillation

The purpose of vacuum distillation is to separate and refine substances.

Vacuum distillation is used in the petroleum and chemical industries. Extremely wide,

For example, the distillation of various organic oils, the distillation of phosphate triesters and dibutyl phosphophthalate in the plasticizer industry

p>Vacuum distillation of synthetic resin raw materials, various high-grade alcohols, high-grade fats

acids, etc., and vacuum distillation of vitamin A,

vitamin E and styrene in the pharmaceutical industry. Distillation of aromatic ethanol and high-grade ethanol esters in the fragrance industry. Refining of oil industry, wine making in food industry, distillation of essence, etc.

Reciprocating vacuum pump

Water ring vacuum pump

Rotary vane mechanical pump

760~10

(1) A factory has a tomato concentrated water vapor injection system pump (pumping capacity of 35 kg/hour), a vacuum degree of 30 Torr, and the use effect is good. The tomato output has nearly doubled. (2) A vacuum system with an annual output of 150,000 tons Compared with salt making in a pan, the salt equipment saves 40% in fuel.

8

Vacuum salt production

Remove all water or volatile components

at a vacuum degree of 50-100 Torr to obtain Refined salt

Slide valve vacuum pump

Water vapor jet pump

Several hundred torr to more than ten torr

A salt factory, vacuum

Salt production (compared to pot salt production

) fuel consumption is reduced by two-thirds

and labor productivity

Increased by four times,

Cost reduced by 44%

9

Vacuum concentration

Applications in the food industry, such as various Juice,

jam, eggs, dairy products (condensed milk, milk powder), water

fructose, etc. Also like the concentration of chemical dyes, acid production, and production

Alkali, and concentration of pulp in the paper industry

10

Vacuum deodorization

Mainly used for the refining of crude oil in the oil industry,

While removing the inherent odor in grease or the odorous substances generated due to gasification and decomposition

, vacuum decolorization is also performed to ensure the quality and color of grease products

< p>11

Vacuum crystallization

Vacuum concentration and crystallization are usually carried out in several "steam tanks", called multi-effect evaporation tanks (such as vacuum concentration and crystallization of salt and sugar production). 4-effect or 5-effect evaporation tanks are often used). Use a vacuum pump to create different degrees of vacuum in the tanks: the pressure in the first-effect evaporation tank (or the boiling point of the concentrated crystallization liquid) is higher than the pressure (or boiling point) in the second-effect evaporation tank, then the first-effect evaporation tank The secondary steam discharged from the inside can be used as the heating steam for the second effect evaporation tank, and so on. Therefore, compared with heating crystallization under normal pressure, vacuum concentration crystallization can greatly improve the utilization efficiency of fuel. Vacuum concentration crystallization is easier to achieve. Mechanization and automation are more conducive to the comprehensive utilization of by-products, so they can effectively reduce costs and greatly improve labor productivity and comprehensive utilization

12

Freeze drying

Freeze drying or sublimation drying. First, the wet material to be processed is cooled so that the moisture or other coal materials are in a frozen state. Then it is quickly placed under vacuum to sublimate directly from the solid state to obtain dry products. Applications of freeze drying: Biology Dehydration of materials; freeze-drying of various organs and tissue sections in biological tissue research; preservation of tissues for transplantation; bacteria, antibiotics, viruses, and vaccines have good resolubility after freeze-drying; plasma, serum, culture fluid, etc. are preserved by freeze-drying The freeze-drying process has a long life, the tissue composition remains unchanged, and the re-solubility is good; the freeze-drying process has also developed rapidly in the food industry, and is used in many foods (such as meat, aquatic products, grains, dairy products, fruits, Eggs and beverages, etc.) can be processed into freeze-dried products. Its unique advantage is that the nutrients, color, aroma and taste of the food are preserved to the maximum extent, and it is light in weight, small in size, long in storage and has a low rehydration rate. Reaching more than 9o%

Roots booster pump + mechanical pump

Oil diffusion pump + mechanical pump

Water vapor jet pump

1~10-3

The 2-ton vacuum freeze-drying equipment of a canned food factory uses a water vapor jet pump (60 Torr) to replace the Roots vacuum pump-mechanical pump unit, greatly reducing the cost of freeze-drying products

13

Vacuum impregnation

Dip the impregnating agent into the impregnated material (usually porous material

substance) to improve the quality of the impregnated article. Performance. Under vacuum conditions (or vacuuming first and then processing), an impregnating agent of a certain viscosity is more likely to evenly fill the tiny pores of the impregnated items, so the product performance is better. Vacuum impregnation is widely used in the electrical insulation industry.

If the insulation material is immersed in fibrous materials, its insulation performance and service life can be greatly improved

Rotary vane pump

Slide valve pump (water vapor jet pump)

<5

<1

A few pallets to dozens of pallets

Various motor factories, insulation material factories, carbon factories, and a certain domestic refractory material The factory successfully used vacuum impregnation technology when producing the new product "

Sliding Nozzle" for molten steel ladles. The sliding surface of the two nozzles is larger than

8, thus solving the problem of molten steel. Leakage problem

14

Vacuum humidification

Natural fibers (such as silk), man-made fibers, tobacco, paper and other products need to adjust their moisture content (mainly is to increase its moisture) to make its moisture content uniform and constant. 1. Inject water vapor; 2. Inject hot water through the separator; 3. Mix steam and water and inject through the separator. Humidification of silk usually requires vacuum drying and cooling again after injecting water or steam to ensure uniform and moderate humidity control

Water ring vacuum pump

Steam jet pump + water ring vacuum pump

Water steam jet pump

1~20

At present, in our tobacco industry, water ring vacuum pumps (SZ-3) are mostly used for tobacco vacuum resurgence. The disadvantage is that the vacuum degree is low, and the moisture resurgence cycle is not easy to penetrate at a suitable resurgence temperature. If the resurgence temperature is increased, the quality of the tobacco leaves will be damaged. A cigarette factory switched to a water vapor jet pump. The processing vacuum degree is increased and the moisture regain quality is improved.

15

Vacuum chromizing

Chromium produces large vapor pressure and chromium vapor at a vacuum degree of 10-2 Torr above the vaporization temperature (917°C) Atoms are deposited on the steel surface and undergo thermal diffusion, thereby forming a strong layer of ferrochromium alloy on the surface, which has properties such as high temperature oxidation resistance and corrosion resistance. Vacuum chromizing is one of the effective ways to extend the life of parts and save metal elements.

Rotary vane pump

Slide valve pump

Water vapor jet pump

≤10-2

Domestic Some factories have successfully used

16

Vacuum heat treatment

During heat treatment in the atmosphere, the metal heating surface will be oxidized by oxygen, water vapor, etc. to generate oxidation Materials. The cost of using high-purity inert gas as a protective atmosphere is very high. Vacuum is not only a "cheap" inert atmosphere, but also can remove the original oxides on the metal surface under vacuum conditions, leaving very little after treatment. Deformation occurs, thereby minimizing the machining allowance or even requiring no processing at all after treatment. Since the degassing effect of vacuum can improve the strength and wear resistance of the product, the vacuum heat treatment process is stable, and the heat treatment furnace can almost It is fully automated, and it is also a safe, smokeless and odorless process. At present, the practical application of vacuum heat treatment is limited to high-grade tool steel and special steel (such as high-alloy steel and high-speed steel), especially those with complex shapes. Products that do not need to be ground after treatment

Mechanical pump + diffusion pump

Water vapor jet pump

10-1~10-3] High vacuum first and then regular Heating at a pressure of about 0.1 Torr to avoid high steam pressure such as Cr and Mo

Gold volatilization loss

Japan conducts salt heat treatment on SKH and cold forging dies, and the processing allowance is It is 0.15-0.3 mm, and then grinding and polishing

processing. However, after switching to vacuum heat treatment, the processing allowance is only 0.08 mm.

Japan used to use salt bath heat treatment for SKD11 cold forged die steel (to produce stainless steel screws). The average number of molds formed was about 20,000 to 25,000 pieces. After changing to vacuum heat treatment, the molds can be used directly without processing

after treatment. The service life is extended by 3-4 times

17

Vacuum ion nitriding

Ion nitriding is to place the workpiece to be processed in a vacuum container. Then it is filled with Injecting nitrogen-containing gas. After passing in DC high-voltage electricity, the surface layer of the workpiece is bombarded and penetrated into nitrogen atoms, and a nitrided layer is formed. The surface heat}Lm cutting method has the advantages of short nitriding time, small deformation, and wear resistance. , brittle resistance, save ammonia, save electricity, improve working conditions, achieve no pollution and other advantages, it is a promising new method of surface heat treatment

Rotary vane pump + mechanical pump

< p> 1~10

18

Vacuum refrigeration

Water has different boiling points under different pressures, and at the boiling point temperature, the water becomes the same The high-temperature steam needs to absorb the vaporization heat of the large basin and introduce the normal temperature water into the low-pressure container, and the water temperature will eventually drop to the corresponding boiling temperature under that pressure

Mechanical pump

Water vapor jet pump

4~20

It has been widely used in China

19

Vacuum treatment

There are more than a dozen forms of vacuum treatment of molten steel in the metallurgical industry. It is characterized by large processing batches, short time, low cost, and high quality of molten steel. It mainly removes gas and part of the slag inclusions in the steel to greatly reduce its content. The molten steel is deoxidized through vacuum treatment, and the deoxidation products or metal oxides escape from the steel in gaseous state. Therefore, the purity of the treated steel can be close to or reach the level of the vacuum induction furnace. A large number of alloying elements can also be added during the treatment to improve the properties of the steel.

Water vapor jet pump

Mechanical pump + Roots pump

1~0.1

my country's Fushun Steel Plant had one in 1956 20 tons of vacuum processing equipment. Following the completion of the 100-ton D-H vacuum treatment device by Angang Iron and Steel Co., Ltd.

Shanghai Heavy Machinery Factory also has a 100-ton R-H vacuum treatment device, and West Germany and Japan have 500-ton vacuum treatment devices with plasma heating

20

< p> Vacuum sintering

Under vacuum conditions, powdered metal or oxide is heated

, formed under pressure (or without pressure) and sintered. Its temperature

Below the melting temperature and above 1000℃, it is especially suitable for metal or oxide products with high melting point. Vacuum sintering does not oxidize, does not decarburize, has dense structure and good quality. Required vacuum degree: pure iron 0.1-0.01 Torr; stainless steel 0.01 Torr; aluminum inlaid cobalt alloy and magnet 0.1-0.01 Torr; WC, Tic, Ti, Cr and carbide based on them 0.05-0.1 Torr. There are also those that require 10-5~10-8 Torr high vacuum sintering.

Water vapor jet pump

Mechanical pump

Boost pump

Diffusion pump

1~10-2

Used to improve the quality of carbonized zinc-based steel structural cemented carbide, vacuum sintering of micro-carbon ferrochrome, and improve performance

p>

21

Vacuum smelting

The quality and performance of metals can be improved through vacuum smelting, sintering, heat treatment and other processes. Vacuum metallurgy has unique advantages: ① Make metal And the gas and inclusion content in the alloy are greatly reduced, improving performance. ② The chemical composition can be accurately controlled to make the alloy performance stable.

③ Improve the density, uniformity and plasticity, and eliminate white spots, segregation and cracking of steel ingots ④ It can melt metals such as titanium, zirconium, uranium and other metals that cannot be melted and cast in the atmosphere. Vacuum is widely used in stainless steel, electrical steel, bearing steel, high-temperature alloys, etc. Smelting and casting of refractory metals

Steam jet pump

Rotary vane pump

Spool valve pump

Boost pump

p>

Diffusion pump

1~10-5

my country already has several tons of vacuum induction furnaces, self-consumption protection, 200-600 kilowatt electron bombardment furnaces and other metallurgical equipment , There are 250 tons of vacuum electric arc furnaces abroad, and there is a 12,000 kilowatt electron bombardment furnace in the United States

22

Vacuum coating

Solid ( The technology of depositing metal

or non-metal (semiconductor, dielectric) thin films on the surface of substrate). It is widely used in the radio industry (integrated circuits, resistors, capacitors), the electric vacuum industry (camera tube targets, picture tubes), the optical industry (astronomical reflectors), the atomic industry and aviation technology, and the gold wire in the light textile industry. Silver wire, plastic metallization, film for trademark packaging, mirror making, etc. also use vacuum coating technology

Rotary vane pump, booster pump, Roots pump, diffusion pump, ion pump, sublimation pump

p>

10-2~3*10-9

Each vacuum equipment factory in my country has its own series of vacuum coating machines, such as evaporation, sputtering and ion coating machines. Examples include light filtering Film, laser film, spectroscopic film, luminescent film, anti-reflection film, magnetic film, superconducting film and aluminized mirror using aluminum instead of silver, etc.

23

Low-temperature insulation

p>

Medium vacuum (>10-3 Torr) insulation has been widely used, such as low-temperature liquefaction equipment, low-temperature storage and transportation equipment, low-temperature simulation tests and superconducting magnetic field insulation, etc.

Rotary vane Type vacuum pump, booster pump, diffusion pump

10-3~10-5

The evaporation rate of a 20m3 vacuum powder insulator in a factory is 0.5% per day, and there are also liquid ammonia containers, etc.

24

Petroleum Industry

From oil well degassing, water injection deoxygenation, storage and transportation

Abatement of exhaust gas to refinery It is widely used in pressure distillation, petroleum product refining, dehydration and degassing of grease, vacuum filtration, etc.

Reciprocating pump

Rotary vane pump

Water ring pump

Steam jet pump

10~700

Vacuum distillation - every refinery has more than one set of devices, various types

Vacuum filtration and degassing low-temperature devices have been generally built

25

Others

The application range of vacuum is extremely wide. In addition to the above main aspects, there are many aspects that have their specific applications. Such as vacuum packaging, vacuum manipulator, vacuum storage, vacuum storage of grain seeds and tree species in agriculture and forestry, electric porcelain and civil construction

Vacuum mud refining, vacuum adsorption, dehydration of cement asbestos products, vacuum in casting production Negative pressure molding, vacuum die-casting, etc.

You can refer to the details below!