Free-Form Kneader Vane Geometry for Shear Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional mixing and kneading machines with sinusoidal axial motion of kneader vanes and pins are limited in generating complex shear and extensional flow fields, resulting in maximum energy dissipation only at a line, restricting the processing of bulk-flowable and pasty masses.
Innovation Solution
The main surfaces of kneader vanes and pins are configured as free-formed surfaces, allowing for varying gap sizes and profiles between them, enabling enhanced mechanical energy input and customized shear and extensional flow zones through rotational and translational motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional machining methods (turning, milling, electrical discharge machining) are used to produce main surfaces of kneader vanes and pins, then manufacturing simplicity is maintained, but only relatively simple surface geometries can be generated resulting in limited shear and extensional flow fields
Solution Approach 1:
The patent applies free-formed surfaces with complex curvatures to the main surfaces of kneader vanes and pins, replacing conventional flat or simple curved surfaces. This enables the generation of sophisticated shear and extensional flow fields that were not achievable with traditional machining methods, directly resolving the contradiction between geometric simplicity and flow field complexity.
Solution Approach 2:
The patent changes the geometric parameters of the kneader vane and pin surfaces by introducing free-formed surface geometries with varying curvature radii, angles, and profiles. This allows optimization of shear velocities and energy dissipation distribution throughout the processing zone, enabling adaptable surface geometries for different processing requirements.
2Productivity
If sinusoidal axial motion of kneader vanes is used, then mixing and kneading functions are achieved, but maximum shear velocity occurs only at a line or point resulting in localized energy dissipation
Solution Approach 1:
The patent applies different surface geometries to different regions of the kneader vanes and pins. By varying the local surface characteristics (curvature, angle, profile) across different zones, the patent creates differentiated shear and extensional flow fields that distribute energy dissipation more uniformly throughout the processing volume, rather than concentrating it at a single line or point.
Solution Approach 2:
The patent transitions from line-contact shear zones to area-contact shear zones by introducing complex three-dimensional free-formed surfaces. This dimensional expansion allows shear and extensional flows to occur across extended surface areas rather than confined to linear paths, improving energy distribution and processing uniformity.
3Adaptability or versatility
If the gap between kneader vane and kneader pin is fixed by conventional geometry, then manufacturing is simplified, but the ability to vary gap size and profile for optimized energy input is restricted
Solution Approach 1:
The patent employs free-formed surfaces with complex curvatures on the main surfaces of kneader vanes and pins, enabling the gap between them to vary in size and profile according to optimized processing requirements. This provides flexible gap configuration that can be adjusted for different energy input needs while maintaining manufacturability through modern free-form machining techniques.
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 allows for optimized shear effects and energy distribution across the processing area, improving the processing of bulk-flowable and pasty masses by adapting shear velocities and flow zones to specific requirements, enhancing the efficiency and flexibility of the mixing and kneading process.
Implementation Method 1
creating the desired shear/mixing and kneading functions in the various processing zones
Implementation Method 2
varying the shear and extensional flow zones generated in the working space
Data Source
AI summary
The mixing and kneading machine (1) for compounding bulk-flowable, plastic and/or pasty masses comprises a working space (9) enclosed by a casing (2), and a working member (3) moving rotatingly and translationally in the casing (2). The working member (3) comprises a plurality of kneader vanes (4). Secured to the casing (2) are kneader pins (6) which protrude into the working space (9). To optimize processing, the main surfaces of the kneader vanes (4) and/or of the kneader pins (6) are configured at least in part as main surfaces (23a-23f).