Analysis of important applications of jet pumps for generating vacuum

Jet pumps are widely used to transport, compress, and mix gases and vapors, liquids, and solids. Gases or liquids are often used as a power medium. The use of jet pumps to create vacuum is another very important application.

The main principle of the jet pump is that the power nozzle drives and accelerates the surrounding liquid, gas or solid at a high velocity. This movement results in a mixture of drive and driven material. The velocity of the jet is reduced at the diffusion and the pressure is increased. Unlike conventional pumps, the jet pump has no moving parts when it is in operation.

Jet pumps can be made from a wide variety of materials such as cast iron, steel, stainless steel, Hastelloy, titanium, enamel, glass, plastic and graphite, and can be made in a variety of sizes. The suction can be from 1 to 2000000 m3/h, and the suction pressure can reach a range of several centimeters to more than 30 meters.

Because of the diversity of jet pumps, they have been widely used in various fields, such as chemical reactors, exhaust systems, water treatment equipment, mixing tanks, storage tanks, wastewater treatment equipment, heating systems, heating gas supply systems, power plants, Swimming pool, water supply from the factory, etc. And the formation of vacuum in different industrial fields.

The formation of a vacuum by a jet pump using water vapor as a power medium is an important application area. The high-speed injection that it delivers is equivalent to several times the speed of sound, so the jet pump can also easily handle large volumes of material in a vacuum.

Because single-stage jet pumps can only overcome extremely limited compression ratios, several jet pumps must be installed in series when the suction pressure is low. The suction pressure of the multi-stage steam jet vacuum pump can be as low as 0.01 mbar. In order to condense most of the motive water vapor and to minimize the amount of suction in the next stage, a condenser is typically placed between the two jet pumps. Depending on the application, a direct contact condenser or surface condenser is used.

In the jet pump, water vapor is mainly used as a power medium. In most industries, water vapor is produced in large quantities as a basic energy and is therefore very easy to obtain. In the condensation process of power steam, more or less wastewater is produced. Although the amount is small, and even if the waste water discharge cost is taken into consideration, the steam jet pump is still the most economical vacuum pump, but it always has a certain negative impact on the vacuum jet pump.

As an option, therefore, product steam is increasingly being used in the operation of jet pumps. For example, solvent vapor, chlorobenzene, toluene, butanediol, ethylene, ethylene glycol, furan.

In this case, evaporation of the power steam after condensation is utilized as a power medium. Due to the low evaporation temperature of organic steam, in most cases, this mode of operation is more conducive to energy savings than running with steam.

Another important operating range of jet pumps that use product steam as the power medium is that no water is allowed to mix in the process materials. In order to obtain the best efficiency, the jet pump using product steam as the power medium still needs detailed research.

In terms of structure and function, the jet pump is not much different from the vacuum jet pump using water vapor as the power medium, and has the same advantages: simple structure; safe and reliable operation, no maintenance; long service life, wear resistance Damage; suitable materials can be corrosion resistant; all materials can be manufactured. In addition, since the condensate is recycled, there is no emission pollution.
Jet vacuum pumps are used in a variety of industrial applications, as are several important applications.

In the chemical industry, GEA Jet Pumps has developed a combination pump and it has been widely used. The distinguishing feature of this pump is its compact size and dual design. The two parallel pumps can be operated alternately and independently, so that maintenance can be carried out without stopping.

In the chemical industry, if stainless steel does not meet corrosion resistance requirements, a ceramic/graphite vacuum jet pump can be used to remove corrosive gases and water vapor. The jet pump is made of ceramic and the surface condenser is made of graphite. The surface condenser is a combination of a compact condenser. This structure has the advantages of small size, less space required, and simple assembly on site.

At the refinery, a water vapor vacuum jet pump is used in combination with a liquid ring pump for the vacuum distillation column system of the refinery. The combination of these two pumps maintains very low steam, water and electricity consumption. GEA Jet Pump's water vapor vacuum jet pump is very suitable for this purpose due to its ability to deliver large volumes of gas (in the range of 104 to 106 m3/h). At the same time, the operation is safe and reliable, and it is not easy to malfunction.

Similarly, the case involving large volume flows is in the vacuum generation of steelmaking degassing. In order to produce a certain quality of steel, some raw steel processing needs to be carried out under vacuum. This vacuum pump must have two functions. One is to quickly evacuate the operating container to achieve the desired pressure. This means that the initial suction of the vacuum jet pump must be large (several thousand kg/h). The second is to remove a large amount of inert gas while maintaining a low pressure (approximately equivalent to several hundred kg / h at 0.6 mbar).

In addition, vacuum jet pumps are used for the deodorization of edible oils, the production of polymers for chemical compounds, seawater desalination, oil dehydration, conditioning of food, beverages and tobacco, suction of spinning baths and many other applications.

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ITC Power Equipment Manufacturing Co., Ltd. ,

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