Tilted Helical Blade Feed Screw for Concrete Compaction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing concrete extruder screws suffer from high wear and inefficiency due to the high feed pressure and vibration required for shear compaction, leading to weakened compaction effects and increased manufacturing costs.
Innovation Solution
The feed screw is designed with a tilted and shaped helical blade that enhances compaction by creating an acute angle with the central axis, reducing pressure and wear, and using a wear-resistant coating on the trailing side and a low-friction material on the leading side, optimizing the screw's geometry for improved compaction and reduced backflow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high feed pressure and vibration are used for shear compaction, then compaction efficiency is improved, but screw wear increases
Solution Approach 1:
The screw blade is designed with different surface properties on different sides: the trailing side has a tilted surface (acute angle with central axis) for enhanced compaction, while the leading side has a low-friction material coating to reduce wear. This local differentiation allows the screw to achieve both high compaction efficiency and reduced wear simultaneously.
Solution Approach 2:
The screw blade uses composite material construction with a wear-resistant coating on the trailing side and a low-friction material on the leading side. This composite approach enables the screw to withstand high feed pressure and vibration while minimizing wear, resolving the contradiction between compaction efficiency and screw durability.
2Ease of manufacture
If traditional screw geometry is used, then manufacturing is simple, but compaction effect is weakened
Solution Approach 1:
The screw blade geometry is made asymmetric with the trailing side tilted at an acute angle relative to the central axis, creating a wedge-shaped compaction zone. This asymmetric design enhances the compaction effect by directing concrete particles toward the center during rotation, while still being manufacturable using standard machining processes.
Solution Approach 2:
The tilted surface of the trailing side creates a curved compaction path that guides concrete particles in an arc toward the central axis. This curved geometry enhances compaction effectiveness compared to flat surfaces, while maintaining manufacturability through conventional surfacing operations.
3Productivity
If high vibration power is used, then compaction result is improved, but noise and wear increase
Solution Approach 1:
The invention replaces high-power vibration-based compaction with a mechanically-driven shear compaction system. The tilted screw blade geometry creates controlled shear forces that compact concrete through directed particle movement rather than random vibration, achieving effective compaction with lower noise and reduced wear on equipment.
4Ease of manufacture
If screw blade is flat and perpendicular to movement, then manufacturing is easy, but compaction efficiency is reduced
Solution Approach 1:
The screw blade transitions from a symmetric flat design to an asymmetric tilted design where the trailing side forms an acute angle with the central axis. This asymmetric geometry creates a wedge effect that actively pushes concrete particles toward the center during rotation, significantly enhancing compaction efficiency while remaining compatible with standard manufacturing processes.
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 design increases compaction efficiency by 10-25%, reduces screw wear, and shortens the forming sleeve, resulting in lower cement usage and manufacturing costs, with improved product cohesion and reduced curing time.
Implementation Method 1
the work movements are in an appropriate direction. In the case of a dry, zero-slump mass, the pressure waves are rapidly suppressed and therefore a greater deal of vibration power is required in order to create the desired compaction result. The great and often high-frequency vibration leads to wear, excessive noise and other detriments. For this reason, the most highly-developed extruders are nowadays based on the shear-compaction method.
Implementation Method 2
using a wear-resistant coating on the trailing side and a low-friction material on the leading side, optimizing the screw's geometry for improved compaction and reduced backflow.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Method, arrangement, and feed screw for feeding and compacting a concrete mass in an extrusion casting machine, which arrangement comprises at least one feed screw (5) for feeding the concrete mass and elements (8, 9) for rotating the screw (5), in such a way that its helix pushes the mass parallel to the central axis of the screw. Further, in the arrangement, there are elements (11, 12, 13) for moving the feed screw (5) forwards and backwards inside the mass. The feed screw (5) is shaped in such a way that the surface (16) of the side of the helical blade (15) of the feed screw (6), which is on the trailing side of the helix, is at least over part of the height (h) of the helix tilted in the direction of the trailing side, in such a way that a straight line (19) drawn from the intersection (17) of the helical blade (15) on the trailing side of the helical blade and the casing (14) of the screw to the point ( 18) of the helical blade, in the same cross-section, forms, over at least part of the length of the helix, an acute angle (a) with the central axis (K) of the screw in this cross-section.