Analysis on damage factors of dry screw vacuum pump

1、 Analysis on the causes of corrosion on the rotor surface of screw pump the feed medium of vacuum pump contains sulfur dioxide and water. Sulfur dioxide combines with water to form sulfurous acid. Sulfurous acid has corrosive effect on metal. In order to prevent corrosion of rotor and pump cavity, Teflon layer is coated on the surface of rotor and pump cavity. Corrosion of rotor and pump chamber indicates that the layer is damaged and sulfite has corroded to the pump chamber. 2、 Cause analysis of Teflon layer damage in rotor and pump chamber there may be three reasons for the damage of Teflon layer on the surface of rotor and pump chamber: first, solid particles enter the pump chamber and cause coating damage. Second, chemicals form colloid on the pump cavity and rotor 1、 Cause analysis of surface corrosion of screw pump rotor The feed medium of the vacuum pump contains sulfur dioxide and water. Sulfur dioxide combines with water to form sulfurous acid. Sulfurous acid has a corrosive effect on metals. In order to prevent corrosion of rotor and pump cavity, Teflon layer is coated on the surface of rotor and pump cavity. Corrosion of rotor and pump chamber indicates that the layer is damaged and sulfite has corroded to the pump chamber. 2、 Failure analysis of Teflon layer in rotor and pump chamber There may be three reasons for the surface layer damage of rotor and pump chamber: First, solid particles enter the pump cavity, which causes coating damage. Second, chemicals form colloid on the pump cavity and rotor, which carbonizes and hardens and destroys the coating of rotor and pump cavity. Third, other reasons. 1. Failure analysis of solid particles Check the pump inlet equipment and pipeline, and no free moving solid particles such as metal fragments and iron chips are found. 2. Analysis of colloidal carbon deposition failure Fig. 1 is a picture of the attachment on the inner wall of the pump inlet pipe. The substance is dark brown. After analysis, it contains iron, carbon and oxygen. It is a polymeric substance such as butadiene and sulfolane, which is bonded to the inner wall of the pipe. If the substance adheres to the pump cavity and rotor surface, it is easy to carbonize and harden, thus damaging the rotor surface layer. 3. Process factor analysis The gas phase outlet pressure of the vacuum pump is 80kPa (a), which is negative pressure, while the liquid phase outlet of the pump is normal pressure. Under normal circumstances, the liquid at the pump outlet cannot normally enter the underground liquid tank, resulting in backflow, resulting in the accumulation of liquid substances at the pump outlet. These liquid substances contain sulfurous acid, and the accumulation of sulfurous acid at the pump outlet forms impact corrosion to the vacuum pump, It should be said that the backflow of liquid at the pump outlet is the main reason for the corrosion of pump rotor and pump cavity.

Dry screw vacuum pump for yarn steaming machine