Variable Pitch Screw Pump Prevents Bubble Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fluid transport devices, such as uniaxial eccentric screw pumps, face issues with bubble generation due to negative pressure in the transport space when dealing with highly volatile or gas-containing fluids, leading to defects in applications like coating.
Innovation Solution
A fluid transport device with a stator and rotor configuration that decreases the transport space capacity in the flow direction by reducing screw pitches, sectional area, increasing rotor diameter, or decreasing eccentricity, ensuring the fluid remains constantly pressurized and bubble-free.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the transport space is larger on the downstream side than on the upstream side due to dimensional tolerance, then the fluid transport device can accommodate manufacturing variations, but the transport space may have negative pressure to cause the fluid to generate bubbles
Solution Approach 1:
The patent changes the pitch parameters of the screw threads from constant to variable, with the pitch gradually decreasing in the flow direction from inlet to outlet. This parameter change ensures that the transport space capacity continuously decreases, maintaining positive pressure throughout the transport process and preventing bubble generation even when accounting for dimensional tolerances in manufacturing
Solution Approach 2:
The patent applies preliminary anti-action by designing the transport space to progressively decrease in capacity before negative pressure can develop. The decreasing pitch configuration pre-compresses the fluid continuously, preventing the formation of negative pressure zones that would otherwise cause bubble generation in highly volatile or gas-containing fluids
2Device complexity
If the transport space capacity is constant or increases in the flow direction, then the device structure is simpler, but the fluid may experience negative pressure and generate bubbles
Solution Approach 1:
The patent transforms the constant pitch parameter into a variable pitch parameter that decreases progressively in the flow direction. This modification increases device complexity slightly but ensures continuous fluid pressurization and reliable bubble-free transport, particularly for highly volatile liquids and fluids with dissolved gases
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The configuration effectively prevents bubble generation by maintaining positive pressure within the transport space, ensuring fluid quality and performance in applications like coating and application.
Implementation Method 1
a rotor having a male screw shape, inserted through the through hole of the stator to form a transport space between the rotor and an inner circumferential surface of the through hole, and configured to rotate
Implementation Method 2
The through hole of the stator has interference pressed by the rotor to be elastically deformed
Implementation Method 3
a capacity of the transport space is decreased in the flow direction... causes the fluid to be constantly pressurized during transport
Data Source
AI summary
The present invention comprises: a stator 2 that is cylindrical and has a through hole 10, the through hole 10 in the shape of a female screw and being formed at a certain pitch in the flow direction from an inlet to an outlet; and a rotor 3 that is formed in the shape of a male screw, is inserted into the through hole 10 of the stator 2 to form a transport space 11 with the inner circumferential surface of the through hole, and rotates to move a fluid from the inlet to the outlet through the transport space 11 while being inscribed on the inner circumferential surface. The volume of the transport space 11 is reduced toward the flow direction. This prevents, reliably, the occurrence of bubbles from a fluid at a downstream-side when the fluid is transported through the transport space 11 formed between the stator 2 and the rotor 3.