Any pressure below atmospheric pressure is called vacuum. Vacuum is the degree below atmospheric pressure, usually expressed as a percentage or millimetre column of water (or mercury). If the vacuum degree of a certain equipment is 80%, it means that the pressure in the equipment is 20% of the atmospheric pressure, that is, when the atmospheric pressure is 1 kg/cm ^ 2, the pressure in the equipment is 0.2 kg/cm ^ 2. Thus, when expressed as a percentage, the degree of vacuum is the degree to which the gas is extracted. If the vacuum degree is 3×10-2 mm, the pressure in the equipment is 3×10-2 mm.
In chemical factories, some production processes are usually carried out under atmospheric pressure, such as vacuum evaporation, vacuum distillation and vacuum filtration.
In order to achieve a vacuum, it is necessary to have the equipment to extract gas – vacuum pump. Vacuum pump can be roughly divided into reciprocating, rotary, jet pump.
1. Reciprocating vacuum pump
Reciprocating vacuum pump and reciprocating compressor work on the same principle, but the valve mechanism is different. In reciprocating compressor are generally used in the spring valve, and in the reciprocating vacuum pump most of the so-called slide valve valve distribution mechanism.
2. Water ring vacuum pump
Water ring vacuum pump is a kind of rotary vacuum pump, except for pumping gas, can also be used for compressed gas. For example,
The maximum pressure of water ring vacuum pump can reach 1.5 kg/cm squared, so it is also called water ring compressor. This type of pump work to avoid solid particles into the pump body.
Water ring vacuum pump in chemical industry of application
The best characteristics of chemical industry pump should be: high quality, high reliability and high environmental protection performance; It is beneficial to the health of workers while completing the task of chemical medium transportation. Minimum expected service life; Can be combined with the whole set of chemical equipment into an organic whole. However, in the process of chemical production, various specific conditions and purposes of use and chemical pump manufacturing put forward a variety of different requirements.
The prominent features of the mechanical products used in the chemical industry of water ring vacuum pump are:
The properties and requirements of mechanical products vary with the types and properties of the chemical medium transported. Of course, the medium mentioned here sometimes refers to water, oil or other non-harmful substances; In most cases, however, chemical media refer to some very “terrible” chemical raw materials; For example, some media with serious hazards (toxic, corrosive and inflammable); Especially some easy to produce chemical reactions, corrosion, erosion of the medium or contains the above components of the solid or gas medium. Chemical composition change and chemical element ratio change in water ring vacuum pump multiple chemical medium will lead to chemical medium property change; Lead to the improvement of chemical medium concentration or special activity properties. Water ring vacuum pump, ycb-g heat preservation gear pump often puts forward special strict quality requirements for the purity of chemical medium, and these special strict quality requirements can be easily realized by appropriate chemical pump.
(a) from the diversity of chemical medium derived from the diversity of chemical pump requirements. This makes chemical pump standard system is difficult to become a simple standard system. Compared with other fields, such as household electrical, household heat extraction, water supply, drainage and so on, as well as chemical refining or automobile manufacturing, standardization has reached a considerable level not only in the production of products, but also in the use of products. But in the chemical production enterprise, the chemical pump standardization work has encountered the barrier in the technical aspect and the economical aspect.
(2) water ring vacuum pump where there is the possibility of vacuum pump optimization and improvement? First of all, standardization is very helpful and meaningful for the production and use of chemical pumps. However: from the life cycle of the use of high and low Angle gas end can carry a large load (that is, the resistance is very large), and even plug.