Hopper Structure with Axial Insert for Uniform Granular Flow
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Solution Overview
Problem
Existing hopper structures for dehumidifying granular materials often result in non-uniform flow patterns, leading to uneven drying and potential quality issues in processed products due to the formation of preferential paths and stagnant zones, which complicates achieving the optimal dwelling time for uniform dehumidification.
Innovation Solution
A hopper structure equipped with a hollow axial insert extending throughout the hopper's height, featuring conical ends and a cylindrical intermediate section, which controls the descending flow by maintaining constant speed vectors across the hopper's cross-section, preventing preferential paths and stagnant zones, and optimizing the tapering angles based on the material's rheological properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional hopper structure is used for dehumidifying granular materials, then the drying process can be performed, but non-uniform flow patterns occur leading to uneven drying and quality issues
Solution Approach 1:
The hopper is segmented into distinct flow zones by inserting a central insert that divides the granular material flow into multiple pathways. This segmentation prevents the formation of single preferential paths and promotes uniform mass flow across the entire cross-section, ensuring all material receives consistent drying treatment.
Solution Approach 2:
The central insert creates localized flow control zones with different characteristics. The insert's surface properties and geometry are specifically designed to modify the local flow behavior of granular material in contact with it, creating friction zones that redirect material flow and prevent stagnant areas while maintaining overall mass flow uniformity.
2Ease of operation
If the hopper allows natural flow of granular material, then the discharge process is simple, but preferential paths and stagnant zones form causing non-uniform dwelling time
Solution Approach 1:
The central insert acts as an intermediary element between the hopper walls and the granular material flow. It mediates the flow by providing a controlled friction interface that redirects material pathways, preventing direct contact between material and hopper walls that would create preferential paths, while maintaining continuous flow without requiring complex mechanical intervention.
3Quantity of substance
If hot air is blown into the hopper for dehumidification, then the drying process is effective, but non-uniform flow patterns cause uneven humidity removal
Solution Approach 1:
The central insert creates equipotential flow conditions by ensuring all granular material particles experience similar flow velocities and residence times regardless of their initial position in the hopper. This uniformity in flow potential ensures that hot air distributes evenly throughout the material mass, achieving uniform humidity removal across all particles.
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 ensures a uniform descending flow of granular materials, enhancing the homogeneity of drying and reducing the risk of quality defects by maintaining consistent humidity levels across the material, thereby improving the mechanical characteristics of the final product.
Implementation Method 1
During an unloading step of the material loaded in a hopper, the downwards flow of loose material... the moduli of speed vectors of the various granules in the hopper at a right cross-section plane of the hopper are, if not identical, very similar to one another
Implementation Method 2
The removal of humidity from hygroscopic granules is necessary because, during melting of granular material being processed at relatively high temperature, any water possibly remaining within granules can slip into the polymer molecular chains
Implementation Method 3
a hot and dried air generating device, generally termed 'dryer', that is designed to blow hot and dried air (processing air) into the hopper. Once inside the hopper, the processing air flows through the whole mass of granules of plastic material to be dehumidified
Data Source
Figure 1a~1b
Figure 2
Figure 3a~3c
AI summary
A hopper structure for treating granular material, comprising an inner sidewall section arranged, in use, as an upper tubular sidewall, a tapered lower section having a delivery mouth (15) and an elongated insert body (8,9,10,80,90,100,105,122), wherein the insert comprises an upper portion and a lower portion (11,12,13,111,121) arranged at the lower tapered portion of the hopper and having its conicity facing away from the upper portion, the upper portion axially extending from the base of the lower portion up to at least one half of the upper tubular section at an angle λ≥ 0 with respect to a vertical line.