Gypsum Slurry Mixing Path to Suppress Annular Scale

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Solution Overview

Problem

Existing mixing devices for gypsum granules derived from waste gypsum boards with gypsum slurry tend to generate hard and difficult-to-remove gypsum scale on the inner walls, particularly in annular patterns, leading to inefficient operation and maintenance.

Innovation Solution

The method involves feeding gypsum granules from above into the gypsum slurry, ensuring the slurry's upper surface is always exposed to air, and directing the slurry to flow or impinge on the far side of the pipe, preventing annular scale formation by using a flow path and pipe with specific cross-sectional shapes and fluororesin linings to delay scale growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If waste gypsum board is processed into granules and mixed with gypsum slurry, then resource utilization is improved and landfill burden is reduced, but the mixing process becomes complex and contamination control becomes difficult

Engineering Contradiction:
Improvewaste gypsum board utilizationVSAvoidmixing process complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The waste gypsum board processing is divided into separate stages: preprocessing (crushing, screening) to produce granules, then mixing with slurry in controlled proportions. This segmentation allows each stage to be optimized independently, reducing overall process complexity while maintaining high resource utilization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary classification and control system that separates waste gypsum board processing from the main slurry mixing process. This intermediary stage includes granule production, quality control, and contamination filtering, which simplifies the main mixing process while ensuring proper waste material integration.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If waste gypsum board granules are mixed with gypsum slurry, then material utilization is improved, but mixing uniformity becomes difficult to achieve

Engineering Contradiction:
Improvegypsum material utilizationVSAvoidmixing uniformity
Core Design Contradiction:
Loss of substanceVSStability of the object's composition

Solution Approach 1:

The patent applies different quality requirements to different components: waste gypsum board granules are pre-processed to specific size ranges and purity levels before mixing, while the slurry maintains its own consistency parameters. This local quality control ensures that each component contributes optimally to the final mixture's uniformity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The mixing process controls critical parameters including granule-to-slurry ratio, mixing speed, mixing time, and moisture content. By precisely adjusting these parameters, the patent achieves uniform mixing of waste granules with slurry, transforming the composition stability from a problem to a controllable variable.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If waste gypsum board is used as aggregate in plasterboard production, then environmental impact is reduced, but product quality consistency becomes difficult to maintain

Engineering Contradiction:
Improveenvironmental impactVSAvoidproduct quality consistency
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The waste gypsum board undergoes preliminary processing including crushing, screening, and contamination removal before being used as aggregate. This preliminary action ensures that only properly prepared granules enter the mixing process, maintaining product quality consistency while achieving environmental benefits.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements quality control feedback mechanisms that monitor the properties of waste gypsum board granules and adjust mixing parameters accordingly. This feedback system ensures that variations in waste material properties do not compromise final product quality, maintaining reliability while utilizing waste materials.

Inventive Principle:
Principle #23Feedback

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 approach effectively prevents annular scale formation, allowing easy removal of gypsum scale and reducing maintenance downtime, with fluororesin linings providing durability and extending service life.

Implementation Method 1

a mixing device is employed to mix the waste gypsum board granules and the gypsum slurry

Methodology Applied
Scientific EffectMechanical mixing: Stirring

Data Source

PatentEP4357011B1Method for mixing gypsum granules derived from waste gypsum board and gypsum slurry
Publication Date: 2026.05.20 TOKUYAMA CORP
  • EP4357011B1 patent drawingFigure 1
  • EP4357011B1 patent drawingFigure 2
  • EP4357011B1 patent drawingFigure 3~5

AI summary

Hemihydrate and/or anhydrous Type III gypsum granules derived from wasted gypsum boards are fed into a flow path of an aqueous gypsum slurry containing dihydrate gypsum, are mixed with the gypsum slurry, and are fed into a deposition tank of dihydrate gypsum. The gypsum slurry is fed from an inlet of the flow path, and the hemihydrate and/or anhydrous type III gypsum granules derived from wasted gypsum boards are fed into the gypsum slurry from above. The gypsum slurry after mixing is made to flow to an outlet of the flow path while the upper surface of the gypsum slurry is always exposed to air. The gypsum slurry is fed into a pipe by free fall. The gypsum slurry is made to impinge on the far side of the pipe as viewed from the outlet and fall or to fall down the center portion of the pipe. The generation of gypsum scale is suppressed in the mixing device for mixing gypsum granules derived from wasted gypsum boards with gypsum slurry.