Screw Conveyor Flight Recesses for Screen Cleaning and Wear Reduction

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Solution Overview

Problem

Screw separators used for dewatering moist masses experience wear and friction issues, leading to increased maintenance and energy consumption due to clogging and high friction between fibrous materials and the cylinder screen.

Innovation Solution

A screw conveyor with an additively manufactured metallic structure featuring recesses on its outer edge to trap fibrous materials, creating a brush-like surface that constantly cleans the screen device, reducing friction and wear by using wire-based additive manufacturing for efficient material application and wear compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a cylinder screen with thin wall is used to improve filtration efficiency, then screening performance is improved, but wear occurs on the outer circumference of the screw flights and on the cylinder screen leading to drop in throughput

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidwear resistance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by creating recesses at specific locations on the screw flight outer circumference to trap fibrous materials. This localized structural modification allows the screw conveyor to maintain good contact with the screen while preventing fibrous materials from causing wear, thus resolving the contradiction between filtration efficiency and wear resistance

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The recesses act as an intermediary mechanism that captures fibrous materials before they can cause wear on the screen. By introducing this intermediate trapping structure, the patent prevents direct harmful contact between fibrous materials and the screen surface, maintaining both filtration efficiency and reducing wear

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If clearing elements with rotor elements are used to clear screen openings, then screen cleaning is improved, but high friction occurs between fibrous materials and the inner wall of the cylinder screen leading to increased wear and energy consumption

Engineering Contradiction:

Improvescreen clearing efficiencyVSAvoidfrictional energy losses

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent extracts the fibrous materials from the harmful friction zone by trapping them in recesses on the screw flight. This removes the source of high friction before it can interact with the cylinder screen wall, thereby reducing energy losses while maintaining screen clearing functionality

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the previously harmful friction between fibrous materials and the screen into a beneficial trapping mechanism. The recesses capture fibrous materials that would otherwise cause wear and energy loss, transforming a harmful interaction into a useful screening and trapping function

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Ease of manufacture

If conventional manufacturing methods are used for screw flights, then manufacturing simplicity is maintained, but wear compensation and material optimization are limited

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidservice life

Core Design Contradiction:

Ease of manufactureVSDuration of action of stationary object

Solution Approach 1:

The patent applies dynamics by creating a screw flight structure with varying cross-sectional geometry that is optimized for wear compensation. The additively manufactured structure allows for dynamic adaptation to wear patterns, with recesses strategically positioned to trap fibrous materials and extend service life beyond conventional manufacturing capabilities

Inventive Principle:

Principle #15Dynamics

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 solution reduces maintenance needs, lowers energy consumption, and extends the service life of components by minimizing friction and wear, while also reducing material costs and weight through optimized cross-sectional geometry.

Implementation Method 1

the screw flight being an additively manufactured metallic structure and having at the outer circumference an outer edge, in which preferably at least one recess for receiving fibrous materials is arranged

Methodology Applied

Scientific EffectMechanical interlocking:

Data Source

PatentUS20230249425A1Screw conveyor for a screw separator and manufacturing method for a screw conveyor

Publication Date: 2023.08.10 VOGELSANG GMBH & CO KG

AI summary

A screw conveyor comprises a shaft, a screw flight arranged to extend helically around, and connected to the shaft at the outer circumference of the shaft, and extending in axial direction along at least a portion of the shaft, wherein the screw flight has an outer edge at the outer circumference of the screw flight, and at least one recess for receiving fibrous material is arranged in the outer edge of the screw flight. The screw flight has a cross-sectional profile with a width in the region of the outer circumference of the screw flight greater than the width in the region of the inner circumference of the screw flight. Furthermore, the invention relates to a separator device for dewatering moist masses, including liquid manure residues and/or digestates, as well as a method for additively manufacturing a screw conveyor and a use of a screw conveyor.