Screw vacuum pump working principle
The inhaled air first passes through the integrated air filter. The eccentric rotor rotates in the cylinder. The carbon blade moves in the groove of the rotor, and the inertia force pushes the blade towards the rotor. Lubrication reduces friction on the vanes and ensures that the vacuum pump is sealed.
Screw vacuum pump advantages
Absolute oil free operation
Low maintenance requirements
Vacuum pumps can be used as compressors for vacuum pressure applications
Screw vacuum pump and materials causes of friction between
Screw vacuum pump sucks and discharges liquid relying on the volume change of the sealing cavity composed of screw and bushing. In the process of application, it is inevitable to have the problem of wear. Here is the reason why the equipment appears wear:
1. If there are fillers such as calcium carbonate and glass fiber in the material, it can accelerate the wear of screw and barrel.
2. Temperature planning
1) Each of them has an aspirational processing temperature plan. The processing temperature of the barrel should be controlled to make it close to this temperature plan.
2) , in the contraction section and homogenization section, it is assumed that the melting condition of the plastic is disordered and uneven, which will also constitute the accelerated wear.
3) When the granular plastic enters the barrel from the hopper, it will first arrive at the feeding section, and it will inevitably show dry friction in the feeding section. When the plastic is lack of heat and uneven melting, it is easy to form the inner wall of the barrel and the surface of the screw to increase wear.
3. Rotate speed should be adjusted properly:
1) Because some plastics are added with strengthening agent, such as glass fiber, mineral or other fillers. The friction of these materials on metal materials is often much greater than that of molten plastics.
2) In the injection molding of plastics, assuming that high rotational speed is used to improve the shear force of plastics, it will also strengthen more torn fibers correspondingly, and the torn fibers contain sharp ends, which greatly increases the wear force.
3) When inorganic minerals slide at high speed on the metal surface, their scraping effect is not small. So the speed should not be set too high.
4. The screw rolls in the barrel, and the friction between the material and the two causes the working surface of the screw and the barrel to wear gradually:
1) The diameter of the screw is gradually reduced, and the diameter of the inner hole of the barrel is gradually increased. In this way, the cooperation diameter gap between the screw and the barrel increases with the gradual wear of the two.
2) , because the resistance of the head and the splitter plate in front of the barrel has not changed, this increases the leakage flow of the extruded material when it moves forward, that is, the flow of the material from the diameter gap to the feed direction increases.
3) , the effect makes the production of plastic machinery decrease, this kind of phenomenon makes the material stay in the barrel longer, which constitutes the material decomposition. Assuming polyethylene, the hydrogen chloride gas during decomposition enhances the corrosion of screw and barrel.
5. Because the material is not plasticized evenly, or there are metal impurities mixed into the material, the screw rolling torque force suddenly increases, this torque exceeds the strength limit of the screw, so that the screw is broken. This is screw vacuum pump a kind of unconventional accident damage.
Screw vacuum pump has the characteristics of self-priming ability, low noise, high efficiency, long service life, reliable work, etc. no matter how good the equipment is assumed not to be prepared and maintained in time, it is still useless, just like the serious abrasion and untimely treatment will affect the use of the equipment.