Gypsum Plaster Cooling and Dehumidification Process
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Solution Overview
Problem
Existing processes for gypsum plaster production result in unstable phases, water demand issues, and defects due to the presence of calcium sulphate dihydrate and soluble anhydrite, leading to inefficient calcination and setting behavior, with no effective dehumidification and cooling methods to stabilize the product.
Innovation Solution
A continuous process involving a rotary tube cooler with separate stabilization and cooling zones, where gypsum plaster is converted from soluble anhydrite to hemi-hydrate using exothermic energy and then dehumidified and cooled with ambient air, eliminating the need for external water or thermal energy and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If direct calcining processes are used to reduce equipment size and cost, then productivity and thermal efficiency are improved, but phase stability of gypsum plaster deteriorates
Solution Approach 1:
The cooling process is segmented into two distinct zones: a first cooling zone for initial cooling and a second cooling zone for further cooling and dehumidification. This segmentation allows different cooling intensities and methods to be applied at different stages, stabilizing the gypsum plaster phase while maintaining high productivity from the direct calcining process.
Solution Approach 2:
The invention changes the cooling parameters by using ambient air at different temperatures in sequential zones. The first zone uses ambient air for initial cooling, while the second zone uses cooled ambient air for further cooling and dehumidification. This parameter change stabilizes the gypsum plaster phase composition without compromising production efficiency.
2Loss of energy
If gypsum plaster is not dehumidified after cooling, then energy consumption is reduced, but condensation occurs on surfaces leading to deposits
Solution Approach 1:
Ambient air serves as an intermediary medium that achieves both cooling and dehumidification functions. The ambient air absorbs moisture from the gypsum plaster during the cooling process, preventing condensation on surfaces while the energy consumption remains relatively low since the air is sourced from the environment rather than being heated or cooled artificially.
3Ease of manufacture
If calcium sulphate dihydrate and soluble anhydrite are present in gypsum plaster, then the calcination process is simpler, but setting time increases and water demand increases
Solution Approach 1:
The invention performs preliminary cooling and dehumidification of the gypsum plaster in the two-zone cooling system before the plaster is used. This preliminary action converts remaining calcium sulphate dihydrate and soluble anhydrite into the desired hemi-hydrate phase, reducing water demand and optimizing setting time while keeping the calcination process simple.
4Stability of the object's composition
If thermal energy is supplied to convert anhydrite to hemi-hydrate, then phase stability is improved, but energy consumption increases
Solution Approach 1:
The invention converts the ambient air, which would normally just be a cooling medium, into a dual-purpose medium that simultaneously cools the gypsum plaster and dehumidifies it. The natural cooling effect of ambient air is utilized to convert anhydrite to hemi-hydrate phase without requiring additional thermal energy input, thus achieving phase stability while minimizing energy consumption.
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 process produces phase-stable, dehumidified, and cooled gypsum plaster, reducing water and additive demand, enhancing setting behavior, and achieving energy savings and cost-effectiveness while preventing condensation-related deposits.
Implementation Method 1
the gypsum plaster is brought into contact with ambient air and dehumidified by the latter and thereby simultaneously cooled indirectly
Implementation Method 2
the gypsum plaster is brought into contact with ambient air and dehumidified by the latter
Implementation Method 3
soluble calcium sulphate anhydrite is converted to calcium sulphate hemi-hydrate... This is a reversible exothermic conversion during which thermal energy of 210 kJ to 225 kJ per kg of calcium sulphate hemi-hydrate is released
Data Source
AI summary
In a process for the continuous conditioning of gypsum plaster, the gypsum plaster is passed from a calcination facility connected upstream to a gypsum plaster cooler in the form of particles. In the gypsum plaster cooler, soluble calcium sulphate anhydrite is initially converted to calcium sulphate hemi-hydrate and calcium sulphate dihydrate to calcium sulphate hemi-hydrate, and crystal defects are eliminated. Subsequently, the gypsum plaster is brought into contact with ambient air and dehumidified by the latter and thereby simultaneously cooled indirectly.