Clay Kneader Flow Control for Uniform Extrusion
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Solution Overview
Problem
Conventional clay kneaders often generate curvature in the flow pattern of clay density during extrusion, leading to defects in ceramic honeycomb structures, particularly when forming articles with thin partition walls, which complicates achieving uniform quality and strict quality control requirements.
Innovation Solution
A clay kneader design with a drum featuring a pressure raising section, an extrusion section with a smaller inner diameter, and a flow controlling section where the inner diameter gradually decreases from the supply opening to the extrusion opening, along with a rotary shaft and rotating blade that taper to maintain impulsive force, reducing curvature and ensuring uniform columnar article quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional clay kneader with a uniform drum inner diameter is used, then the structure is simple and easy to manufacture, but the flow pattern curves noticeably in the extrusion direction causing forming failures
Solution Approach 1:
The drum is divided into three distinct sections along the extrusion direction: a pressure raising section with larger inner diameter, a flow controlling section with gradually decreasing inner diameter, and an extrusion section with smaller inner diameter. This segmentation allows each section to perform its specific function - the pressure raising section builds pressure, the flow controlling section regulates flow pattern curvature, and the extrusion section delivers the clay. By dividing the drum into functional segments rather than using a uniform diameter, the invention achieves both structural feasibility and flow pattern control.
Solution Approach 2:
Different sections of the drum are given different inner diameters tailored to their specific functions. The pressure raising section has a larger diameter to accommodate high pressure and volume, the flow controlling section has a gradually decreasing diameter to control the flow pattern, and the extrusion section has a smaller diameter for precise extrusion. This local differentiation of structural properties allows each part to optimize its performance for its specific role in the kneading and extrusion process.
2Manufacturing precision
If the inner diameter of the drum is decreased to reduce flow pattern curvature, then flow uniformity improves, but the treatment capacity per unit time decreases
Solution Approach 1:
The drum inner diameter is made dynamic rather than static - it varies continuously along the extrusion direction. The diameter transitions from larger at the pressure raising section to smaller at the extrusion section, creating a gradient that adapts to the changing requirements of the clay flow at different stages. This dynamic dimensional variation allows the system to maintain high treatment capacity in the pressure raising section while achieving flow pattern control in the downstream sections.
3Productivity
If a pressure raising section with large inner diameter is used, then clay treatment capacity increases, but flow pattern curvature increases causing defects
Solution Approach 1:
The flow controlling section acts as an intermediary between the pressure raising section and the extrusion section. It receives the high-volume flow from the pressure raising section and gradually transitions it to the lower-volume extrusion flow, mediating the transition and controlling the flow pattern curvature during the process. This intermediary section prevents the direct connection between large and small diameters that would cause abrupt flow changes and curvature defects.
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 design effectively suppresses curvature in the flow pattern, enabling the production of columnar articles with highly uniform quality, reducing defects in ceramic honeycomb structures and facilitating their formation without forming failures.
Implementation Method 1
The screw 4 disposed in the drum 2 imparts a large shear force to the clay which flows from a supply opening 19 into the drum 2, to knead and homogenize the clay
Implementation Method 2
the rotary shaft has a diameter which gradually decreases toward the extrusion opening in the flow controlling section, and includes a rotary shaft end section around a boundary between the flow controlling section and the extrusion section, and the rotating blade is formed from at least the inside of the pressure raising section to the vicinity of the rotary shaft end section
Data Source
AI summary
A clay kneader has a drum having a pressure raising section on a supply opening side, an extrusion section having an inner diameter smaller than that of the pressure raising section on side of an extrusion opening for extruding clay as a columnar article, and a flow controlling section located between the pressure raising section and the extrusion section and being equipped with a supply opening for clay, a screw having a rotary shaft having a diameter which gradually decreases toward the extrusion opening in the flow controlling section and being ended around a boundary between the flow controlling section and the extrusion section, and a helical rotating blade provided along the rotary shaft for kneading the clay a rotary shaft.