Calcination Plant Gas Recirculation Control

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Solution Overview

Problem

Calcination plants are energy-intensive and sensitive to fluctuations in the moisture content of raw gypsum, affecting the quality and processing of calcined gypsum, with existing systems either being very energy-intensive or dependent on non-recirculated gas, leading to inefficiencies.

Innovation Solution

A calcination system with a hot gas generator and a control unit that adjusts the combustion air ratio of a heating burner based on moisture content measurements, allowing for recirculation of calcining gas to optimize energy consumption and product quality by controlling the humidity of the calcining gas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If recirculation of calcining gas is implemented to reduce energy consumption, then energy efficiency is improved, but the system becomes more sensitive to moisture content fluctuations affecting product quality

Engineering Contradiction:
Improveenergy consumptionVSAvoidproduct quality consistency
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements a feedback control system where a sensor measures the moisture content of the recirculation gas and feeds this information to a control unit. The control unit adjusts the combustion air ratio of the heating burner based on this feedback to maintain stable calcining conditions despite moisture fluctuations in the recirculating gas, thereby resolving the contradiction between energy efficiency and product quality consistency.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the combustion air ratio parameter of the heating burner dynamically based on measured moisture content. By adjusting this parameter, the system compensates for moisture fluctuations in the recirculating gas, maintaining stable calcining temperature and humidity conditions to ensure consistent product quality while preserving the energy-saving benefits of gas recirculation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If combustion air ratio is adjusted to control moisture content of calcining gas, then product quality is improved, but the system complexity increases

Engineering Contradiction:
Improvecalcination qualityVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control system uses feedback from a moisture content sensor to automatically adjust the combustion air ratio, eliminating the need for complex manual control mechanisms. This feedback loop simplifies the overall control architecture while achieving precise control over calcining gas moisture content and ensuring high product quality.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-regulation by automatically measuring moisture content and adjusting combustion air ratio without external intervention. This self-service capability reduces operational complexity and maintains high manufacturing precision through automated control of the calcination process parameters.

Inventive Principle:
Principle #25Self-service

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 reduces energy consumption and maintains product quality by optimizing calcination conditions, even with fluctuations in the moisture content of the starting material, while minimizing the impact on gas outlet temperature.

Implementation Method 1

a hot gas burner is often provided, which generates heat by burning fuel

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

hot gas generated by the hot gas generator is passed through the calcining reactor as calcining gas

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

it is usually necessary, in addition to the desired drying by evaporating the water present unbound in the raw gypsum

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

hot gas generated by the hot gas generator is passed through the calcining reactor as calcining gas

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 5

FR 2 165 393 A5 proposes recirculating the warm gas emerging from the calcination reactor in order to reduce the use of primary energy

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3176527B1Calcination plant and process for calcination
Publication Date: 2019.02.06 CLAUDIUS PETERS PROJECTS
  • EP3176527B1 patent drawingFigure 1
  • EP3176527B1 patent drawing

AI summary

The invention relates to a calcining plant and a method for calcining powdered or fine-grained materials. The calcining plant (1) according to the invention for powdered or fine-grained materials comprises a calcining reactor (2) and a hot gas generator (4), wherein the calcining plant (1) is configured such that hot gas generated by the hot gas generator (4) is passed through the calcining reactor (2) as calcining gas, and at least a portion of the calcining gas passed through the calcining reactor is returned to the hot gas generator (4) as recirculation gas. The hot gas generator (4) is a heating burner (16) with a combustion air ratio adjustable via a control unit (20).Furthermore, a sensor (22) for measuring the moisture content of the hot gas, the calcining gas, or the recirculation gas is provided and connected to the control unit (20), wherein the control unit (20) is designed to regulate the moisture content of the hot gas, the calcining gas, or the recirculation gas by adjusting the combustion air ratio of the heating burner (16). The method for calcining powdered or fine-grained material relates to the operation of the calcining plant (1) according to the invention.