U-Shaped Rake Screening for Continuous Coarse-Material Removal
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Solution Overview
Problem
Existing screening systems face issues with misalignment of rakes due to coarse debris, leading to operational interruptions and hazards for fish, particularly in sewage treatment plants.
Innovation Solution
The rake bars are designed in a U-shape, arranged as parallel curves, with a combination of linear and pivoting movements, ensuring continuous engagement with screen bars and minimizing alignment issues, while using a drive system comprising a linear drive and pivoting drive for controlled movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rake with straight bars is used to remove coarse material, then the structure is simple, but the rake loses alignment due to coarse debris causing operational interruptions and hazards
Solution Approach 1:
The rake bars are designed with a U-shape curvature instead of straight lines, arranged as a family of parallel curves. This curved geometry allows the rake to continuously engage with screen bars during movement, preventing misalignment and operational interruptions while maintaining structural integrity.
Solution Approach 2:
The rake system incorporates both linear movement along the first legs and rotary movement along circular arcs to dynamically adapt to the curved U-shaped geometry. This dynamic motion pattern ensures continuous engagement between rake bars and screen bars, eliminating alignment loss during operation.
2Object-affected harmful factors
If the rake moves linearly through the liquid flow, then the structure is simple, but it poses crushing hazards for fish swimming in the stream
Solution Approach 1:
The U-shaped curved geometry of the rake bars, arranged as parallel curves, creates a gentler movement pattern through the liquid flow. This curved path reduces sudden linear motions that could crush fish, while the continuous engagement design ensures safe operation throughout the flow area.
Solution Approach 2:
The combination of linear and rotary movements creates a more dynamic and controlled motion pattern. The rotary movement along circular arcs allows the rake to navigate through the liquid flow more smoothly, reducing harmful linear impacts on fish while maintaining effective screening operation.
3Reliability
If the rake is periodically lowered and raised, then the structure is simple, but misalignment occurs requiring replacement or readjustment
Solution Approach 1:
The U-shaped parallel curves of the rake bars are designed to maintain equidistant spacing throughout the movement cycle. This curved geometry ensures that the rake continuously engages with screen bars during both linear and rotary motions, preventing misalignment and eliminating the need for periodic readjustment or replacement.
Solution Approach 2:
The rake system maintains continuous engagement with the screen bars through its U-shaped geometry and combined linear-rotary movement. This continuous action prevents moments of disengagement that would cause misalignment, ensuring stable operation without periodic maintenance intervention.
Data Source
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AI summary
Screening system for the mechanical removal of coarse material from a liquid flow, comprising a screen (2) with a plurality of equidistantly spaced screen bars (3) and a rake (4) movable by a drive and engaging between the screen bars (3), wherein the screen bars (3) are U-shaped when viewed in a flow direction (D) of the liquid flow and are arranged as a set of parallel curves and each comprise first and second legs (3a, 3c) and a circular arc (3b) connecting them, and the rake (4) is movable from a first end position (4a) at the free end of the first legs (3a) linearly along the first legs (3a) to the circular arcs (3b), from there in a rotary movement along the circular arcs (3b) to the second legs (3c) and from there linearly along the second legs (3c) to a second end position (4b) at the free end of the second legs (3c) and back again is.