Oil-free dry-type mechanical vacuum pump working principle brief introduction

do mechanical oil-free vacuum pumps (also referred to as dry-type mechanical pump) is the atmospheric pressure from the pump exhaust start, while gas will be pumped directly into the atmosphere go, pumping cavity without oil or other medium, but also the limits of pump pressure and vacuum pump oil seal or near the same order of magnitude of the mechanical vacuum pump. At present, the use of vacuum in the industry are the majority of mechanical vacuum pump oil, water or other polymers, such as fluid pumps to serve as working media, in the pump from cooling, sealing, lubrication and many other roles. With the development of science and technology, as well as the expansion of the field of vacuum application, the original mechanical vacuum pump and its components of the exhaust system of the urgent need to address two questions: First, the work of medium reflux pump contaminated containers be selected, and such reflux in many cases the impact of product quality, quantity, increased equipment maintenance costs. Secondly, because of some process-reactive substances in the process of vacuum inside so that the serious deterioration of the medium, so that pumps can not work properly. For a general oil-free vacuum system, while the oil seal vacuum pump can be used together with the cold trap or trap Absorption like attachment to prevent reflux, but will not completely solve the problem, but the system seems complex. The use of appropriate types of dry-type mechanical vacuum pump, you can achieve the desired results. Do mechanical vacuum pumps are a wide range of applications, mainly in the following areas: 1) low-pressure chemical vapor deposition of polysilicon in the preparation process; 2) semiconductor etching process. In these production processes tend to use or generate corrosive gases and abrasive particles; 3) In addition to semiconductor process outside the particles produced in certain processes, do not want particles mixed with oil-pumping, and the hope that particulate emissions from pumps, the type used must Do the mechanical vacuum pump to meet the requirements; 4) In the chemical industry, medicine industry, food industry distillation, drying, defoaming, packaging and so on, to prevent pollution caused by organic solvents, suitable for dry-type vacuum pump; 5) to make general Clean oil-free vacuum pump system before class in order to prevent oil pollution. In recent years, dry-type mechanical vacuum pump has been rapid development, foreign companies have large vacuum developed a new type of dry-type mechanical vacuum pump. Domestic units have been much do mechanical vacuum pump to develop the job, such as Northeastern University, Shenyang Institute of Vacuum Technology, Shanghai Vacuum Pump Factory, etc.. At present, the dry-type Mechanical vacuum pumps are mainly classified into contact type and non-contact type. Contact type do have vane pump, cam-type, reciprocating piston, diaphragm-style and so on, the lower the speed of such pumps for small-capacity high compression ratio (single-stage compression ratio). Non-contact type do have Roots-type pump, claw-type, screw type, scroll type, etc., the higher the speed, the application of large-capacity, low compression ratio (referring to a single-stage compression ratio). Do different types of pump has its own characteristics. When used according to different uses to select

About Rotary Vane Vacuum Pumps and Systems

Rotary vane vacuum pumps move fluid through the pump using a rotating assembly in the pumping chamber. Typically there are two or more rotating vanes that move the gas or fluid from inlet to outlet. Rotary vane vacuum pumps are positive displacement pumps. The volume of fluid that is transferred by rotary vane pumps depends upon the size of the housing and the area between each adjacent vane. Larger pumps may have additional impeller vanes. As the rotor turns, the ends of the vane barely touch the housing creating a seal from inlet to outlet. The inlet and outlet are often perpendicular, however for vacuum service applications two inlets may be used, one for air supply and the other for the pumped media. The fluid is pressurized as the volume between the vanes lessens during one half-cycle and is suctioned through an intake port during the other half-cycle.
The movement of the media through the pump can be broken down into three phases in rotary vane pumps: 1) Air or fluid moves through the inlet also known as open to inlet (OTI). 2) The vane rotates clockwise or counterclockwise and seals the media between the vanes and the housing wall also known as closed to inlet and outlet (CTIO). With fluids, this volume should remain constant throughout the cycling process. Gases and/or air may be compressed in this phase causing the pressure to increase before the next phase. 3) The media is moved through to the outlet. This is also referred to as the open to outlet (OTO) volume. The rotor blades are positioned to contain a specific volume of air or fluid. The cyclical movement of the vane creates a smooth flow as the fluid is transferred through the pumping chamber. Generally, materials can be chosen for the vane. For example, carbon vanes can be used with inert gases and a variety of other media types. The vane can be internal or external, rigid or flexible.
The manufacturer for rotary vane vacuum pumps can often give the displacement of the pump. The surface dimensions of the housing and rotary assembly may be considered when calculating flow rate. In some rotary vane pumps, as the flow rate increases, the pressure in the pump chamber increases. Various requirements may be needed including vacuum service or air compression. As with most rotary pumps, the viscosity of the media will affect the speed of the drive chosen. The flow rate is also proportional to the motor speed. Magnetic drive, belt drive or direct drive can be chosen for powering rotary vane pumps.
Rotary vane vacuum pumps can be used in a number of applications providing a pressure or vacuum source for laboratory applications and as well as other automation applications. Smaller sizes may have a maximum flow of 3 LPM with pressures ranging from 80-120mbar.

Type 2X Double-stage Rotary Vane Vacuum Pump

Sealed containers for gas access to the vacuum extraction of the basic equipment for electronics, refrigeration, electric light sources, chemical industry, hospitals, bottle lamps, packaging, dehydration, drying and other industries. (But can not be used for extraction of oxygen is too high, there is explosive, corrosive to metal on the vacuum oil from the chemical reaction and containing the particles, dust gases, can not be used as transfer pumps and the use of compression pumps). The main models have: 2X-2A two-stage rotary vanevacuum pump 2X-4A two-stage rotary vane vacuum pump 2X-8 two-stage rotary vane vacuum pump 2X-15 two-stage rotary vane vacuum pump 2X-30A two-stage rotary vane vacuum pump 2X -70A two-stage rotary vane vacuum pump.