Screw Shaft Diameter Profile for Wear Reduction
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Solution Overview
Problem
Existing solid-liquid separating apparatuses face wear issues with movable plates due to small lead angles, which reduces their lifespan without compromising liquid removal efficiency.
Innovation Solution
Increasing the diameter of the screw shaft section progressively toward the outlet and setting the lead angle to 13° to 14° throughout the screw section, with the prescribed position downstream from the inlet, helps to reduce wear on movable plates while maintaining liquid removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the lead angle of the screw is made small (8° to 9°) to increase liquid removal efficiency, then the efficiency of liquid removal from the object material is improved, but the wear of the movable plates is marked and the lifespan of the movable plates is shortened
Solution Approach 1:
The screw is designed with a variable diameter structure where the shaft section diameter becomes progressively larger from the inlet side toward the outlet side. This creates different local conditions: the smaller diameter at the inlet provides higher shear force for effective liquid removal, while the progressively larger diameter toward the outlet reduces the lead angle effect and distributes pressure more evenly, thereby reducing wear on the movable plates in the outlet region where liquid content is already reduced.
2Productivity
If the lead value of the screw section is reduced to apply large pressure to the object material, then the efficiency of liquid removal is increased, but the pressure concentration accelerates wear of the movable plates
Solution Approach 1:
The screw implements a dynamic diameter profile that changes progressively along its length. The shaft section diameter increases from inlet to outlet, creating a dynamic pressure distribution. This allows the system to apply higher pressure where needed (inlet region) while gradually reducing pressure concentration toward the outlet, thereby maintaining liquid removal efficiency while minimizing wear on the movable plates through the entire screw section.
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
This configuration effectively suppresses wear on movable plates and maintains high liquid removal efficiency by distributing pressure more evenly, extending the lifespan of the apparatus components.
Implementation Method 1
at least one screw extending so as to pass throughout the solid-liquid separating section, the movable plates being formed in such a manner that the movable plates are pushed and caused to move by the rotating screw
Implementation Method 2
a large pressure is applied to the object material present in the outlet side region of the solid-liquid separating section, and hence the efficiency of liquid removal from the object material is increased
Implementation Method 3
the diameter of the shaft section of a screw section on the outlet side of the solid-liquid separating section be made progressively larger toward the outlet side from a prescribed position on the screw, This configuration effectively suppresses wear on movable plates and maintains high liquid removal efficiency by distributing pressure more evenly
Data Source
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AI summary
[PROBLEMS] A solid-liquid separation device having a solid-liquid separation section provided with adjacent stationary plates and movable plates arranged between the adjacent stationary plates and also having at least one screw extending so as to penetrate the solid-liquid separation section. The movable plates are formed such that they are pushed and moved by the screw that rotates.An object to be processed having entered in the solid-liquid separation section is moved toward the exit of the solid-liquid separation section, and at the same time, filtrate separated from the object is discharged to the outside through a filtrate discharge gap of the solid-liquid separation section. Wear of the movable plates are suppressed with dewatering efficiency for slurry maintained at a high level. [MEANS FOR SOLVING PROBLEMS] The diameter (d) of the shaft (41) of a screw section (21A) on the exit side of the solid-liquid separation section (3) gradually increases from a predetermined position (S1) of the screw in the solid-liquid separation section (3) toward the exit side, and the lead angle of the screw section (21A) is set to the range from 10° to 30°.