Pump forvacuum: overview, types, specifications and reviews

A single design of vacuum pumps does not always allow to solve problems requiring high productivity. The increase in operational performance due to the increase in the element base also rarely justifies itself, affects the lowering of the durability of the structure and the stability of the operation of its units. The solution of the problem was the fore-vacuum pump, which provides an autonomous discharge function. As a result, the main equipment gets the opportunity to work with optimal pressure indicators.

Principle of operation of the forequipment unit

Vacuum pumping units operate with several pressure levels, moving from one state to another as work progresses. Forvacuum works under conditions of a preliminary level of vacuum, which must be created with the help of special plunger, mercury or steam oil apparatus. The process of transition from one level of rarefaction to another involves the use of appropriate methods of pumping out the working medium, as well as measuring the pressure. The most effective means of implementing this task is the fore-vacuum pump. The principle of operation of such devices is based on obtaining a preliminary or higher level of vacuum discharge.

The simplest model for realizing this function is demonstrated by a plate-stator pump. In such a design, a cylindrical rotor is rotated. The rotor with the plate divide the cavity into two parts: the first one compresses the working medium, and the second - the expansion. During operation, the for-vacuum pump corrects the pressure parameters, which is reflected in the main installation to which the pre-vacuum system is connected.

Basic characteristics of fore-vacuum pumps

Like all other pumps, forvacuum units are characterized by the rate of supply of the working medium and pressure indices. With regard to productivity, it varies on average from 0.6 to 3000 m ³ / h. The pumping speed is determined by the volume of the vacuum chamber and the time it takes to maintain it. Actually, this will be an indicator of productivity. The compression pressure of the working medium is also taken into account. A standard for-vacuum pump provides about 500 mbar. The working pressure range in the part of minimum values is limited by the ultimate vacuum, which, in principle, is possible for a particular type of equipment. The upper limit is limited by the maximum exhaust pressure, at which point the pump provides a vacuum at the inlet. In particular, the oil-rotational models have a limiting vacuum in the spectrum of 10-3 Torr.

Varieties of structures

There are several approaches to the classification of such aggregates. The most common is the separation according to the principle of action - mechanical and physicochemical models. An example of a mechanical rotary pump has already been considered, and now it is possible to refer to examples of installations operating with gas. For example, plants that provide vacuum by changing the position of the chamber and periodically varying the volumes of the gas content due to the valve are isolated. An alternative to such devices is the sorption modification, which does not pump the gas in batches, but binds it in the system. In this case, both physicochemical and traditional oil-free fore-vacuum pumps differ in the levels of working pressure. So, the models that work with low-, medium- and super-vacuum systems are distinguished.

Manufacturers of pumps

In the segment there are different companies that work on both the domestic niche and the needs of large manufacturing enterprises. For example, the Japanese company Anest Iwata offers pre-vacuum models with a range of performance indicators from 100 to 500 l / min. Also model rulers of dry pumps of this type are offered by the developers of Kashiyama. This company specializes in the production of high-performance spiral and screw type equipment, which provides feed in volumes up to 3500 m ³ / h. In this case, you can find in the family less powerful and inexpensive units with a capacity of about 5 m ³ / h. Famous for the quality and English forvacuum pumps Edwards, in which the latest technology of pumping liquids. The equipment of this brand has proved itself in highly specialized areas. For example, Edwards pumps are used in instrument making, chemical production, in factories manufacturing lighting lamps, etc.

Feedback on forvacuum pumps

Initially, the concept of fore-vacuum pumps suggested the possibility of eliminating conventional pumping structures from instability in operation. Modern optimized systems, supplemented by such devices, are estimated as a single installation for several indicators. Most positive feedback refers to high equipment performance, minimal noise and vibration. Accordingly, the operating time of the main vacuum increases. On the other hand, forecoupling pumps are often criticized for introducing contaminants into the main pumping system. But this applies to oil structures, which gradually leave the market.

Conclusion

The principle of operation of the forecoucaum is also considered obsolete. Addition of the design of pumping equipment by another unit contradicts the idea of optimizing the size of technology, which is sought by modern manufacturers. Nevertheless, today there is no alternative pressure regulator, which could replace the fore-vacuum pump. The price of such units, amounting to 5-10 thousand rubles. In the middle segment, also does not contribute to their spread. However, given the initial exact calculations of system performance, many enterprises manage to effectively use forvacuum. Another thing is that in the future it is necessary to provide for the maintenance costs of this installation, in addition to the main pump.