Shot Blast Drum Agitation Mechanism for Uniform Treatment

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Solution Overview

Problem

Conventional shot blasting apparatuses inadequately agitate works at the bottom of the drum, leading to uneven treatment of small articles and thin parts, with increased collision damage due to lack of effective agitation mechanisms.

Innovation Solution

A drum design with a projecting part for agitation featuring a surface for picking up and a surface for sliding down, connected to both the lower-half and middle parts, enhances agitation at the bottom and reduces collision damage by scooping up buried items and guiding them towards the opening, while maintaining a cylindrical or conical shape for efficient particle injection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional spiral projections are used for agitation, then works at the upper parts are effectively agitated, but works at the bottom of the drum are least agitated and not uniformly treated

Engineering Contradiction:
Improvetreatment uniformityVSAvoidagitation effectiveness at bottom
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The drum interior is segmented into multiple zones with different agitation mechanisms: upper spiral projections for general agitation, and a lower projecting part with picking-up surface and sliding down surface specifically for bottom works. This segmentation allows each zone to address specific agitation needs, resolving the contradiction between overall treatment uniformity and bottom-specific agitation effectiveness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The drum structure is modified with local quality variations: the projecting part at the bottom has specific surfaces (picking-up surface at 45-60 degrees and sliding down surface at 15-30 degrees) tailored for bottom works agitation. This local structural optimization ensures effective agitation at the bottom without compromising the overall treatment uniformity achieved by the spiral projections.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If works are agitated more intensely to improve treatment uniformity, then treatment effectiveness increases, but collision damage between works increases

Engineering Contradiction:
Improvetreatment uniformityVSAvoidcollision damage
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Instead of allowing works to collide randomly during agitation, the invention inverts the approach by providing a controlled path via the sliding down surface. Works are guided to slide down in a controlled manner rather than falling and colliding randomly, thus achieving effective agitation while minimizing collision damage.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The sliding down surface acts as an intermediary between the picking-up surface and the bottom of the drum. It provides a controlled transition path that reduces direct collisions between works, allowing them to slide down gradually rather than falling freely and impacting each other, thus mediating between agitation effectiveness and collision damage prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhanced agitation capability improves treatment uniformity, increasing the frequency of items being agitated at the bottom from 1.7 times/min to 4.7 times/min, and reduces collision damage by effectively moving items without causing them to fall or collide excessively.

Implementation Method 1

a centrifugal injecting device

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

a surface for having the works slide down

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2583791B1Drum for shot blast apparatus and shot blast apparatus
Publication Date: 2017.08.02 SINTOKOGIO LTD
  • EP2583791B1 patent drawingFigure 1
  • EP2583791B1 patent drawingFigure 2
  • EP2583791B1 patent drawingFigure 3

AI summary

The present invention provides a drum for a shot blasting apparatus that uniformly treats the works to be treated by increasing the level of agitation of the works that are buried at the bottom of the drum, and, further, suppressing the traces of collisions on the works, which traces are caused by the works colliding with each other. The present invention also provides the shot blasting apparatus using the drum. The drum comprises a hollow middle part, a lower-half part having the shape of a truncated cone, having a closed bottom, and having a projecting part for agitating that is connected to both the lower-half part and the middle part, and that agitates the works, wherein the projecting part for agitating has at least two surfaces, one being the surface for picking-up the works and the other being the surface for having the works slide down. The shot blasting apparatus of the present invention comprises, in addition to the drum for the shot blasting apparatus, a cabinet and a centrifugal injecting device wherein the cabinet comprises a sealing-wall member consisting of a ceiling-wall, a floor-wall, and both side walls, on the side of the opening of the cabinet. The cover is attached to the drum, and they can turn around as one body.