The three screw pump belongs to the positive displacement rotary pump, which sucks in and discharges liquid by the displacement of several sealed chambers formed by the screw teeth and pump sleeve inside the pump. If there is no theoretical leakage channel between two adjacent sealed chambers in a three screw pump, it is called a strictly sealed three screw pump, and vice versa, it is a non strictly sealed three screw pump.
Three screw pumps have a wide range of applications, characterized by stable flow, small pressure pulsation, self-priming ability, low noise, high efficiency, long service life, small size, and reliable operation. The outstanding advantage is that it does not form eddies when transporting media and can transport various media with a wide viscosity range. It can transport lubricating or corrosive media of various viscosities, non Newtonian liquids of various viscosities, as well as gas-liquid mixed transport and solid-liquid mixed transport. It is widely used in industrial sectors such as offshore platform engineering, petrochemicals, shipping, power, mechanical hydraulic systems, food, paper, sugar, military, and sewage treatment.
The operation process of screw pump:
1. Introduced the formation process, characteristics, and equations of various cycloids. Introduced the design method of screw pump line type - the design process of inverse solution method. This article introduces the specific design method and process of the rotor and stator line types of screw pumps, and derives the equation of the line type, and then derives the equation of the surface type.
2. The principle and process of forming the line shape of the rotor and stator of a 3G screw pump are complex, involving many parameters. Through analysis, the basic parameters required to form the line shape of the screw pump have been determined.
3. Analyzed the meshing process and laws between the rotor and stator during the operation of a single screw pump, and derived and defined the rotor tooth convex contact point and rotor tooth concave contact point from the fixed contact point and flow contact point between the rotor and stator bone lines.
4. The formation principle of the rotor and stator line shape of the insulation screw pump is the external rolling method. During the formation process, it is equivalent to the rotor not moving and the stator undergoing planetary motion. When the screw pump is actually working, the stator does not move and the rotor moves in a planetary motion. In order to match the actual motion mode of the screw pump, the mathematical expression of the sliding speed is derived according to this method. Therefore, the equivalent relationship between the relevant parameters of these two motion modes was analyzed and derived.
5. The formulas for the relative sliding speed of the stainless steel screw pump rotor tooth convex contact point and tooth concave contact point with respect to the stator were analyzed and derived separately. Through specific model analysis, it was shown that the sliding speed of the tooth convex contact point is small at the concave part of the stator and large at the midpoint of the stator convex; The sliding speed of the tooth concave contact point is higher at the moment it leaves the concave part of the stator, and lower at the midpoint of the convex part of the stator; The maximum sliding speed of the tooth concave contact point is the minimum sliding speed of the tooth convex contact point.
6. The method of analyzing the sliding speed of a general internal swing type three screw pump will be applied to the single head ordinary internal swing type high viscosity screw pump commonly used in oil fields, greatly simplifying the analysis process. Afterwards, a detailed and specific analysis was conducted on the GLB800 screw pump commonly used in oil fields, including the magnitude and distribution of the relative sliding velocity between the rotor and stator.
