Radiant Heater Elements for Solid Material Bed Heating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cement industry faces challenges in efficiently heating raw materials for producing cementitious and pozzolanic materials, particularly in achieving continuous heat treatment without the limitations of batch processes and fossil fuel combustion, which results in high CO2 emissions and inefficient heat transfer.
Innovation Solution
A method involving continuous feeding and discharge of solids through a reactor with radiative heating from above and/or sides, where the material bed is mobilized to ensure uniform exposure, and separate elements for conveying and heating are used, allowing for improved heat transfer and control over temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If fossil fuel combustion is used to heat raw materials, then high temperatures are achieved, but CO2 emissions increase and heat transfer efficiency is poor
Solution Approach 1:
The patent replaces the chemical combustion process with electrical resistance heating elements. The heating elements are electrically heated and placed in direct contact with the material bed, substituting the mechanical/chemical combustion system with an electrical heating system. This eliminates CO2 emissions from fuel combustion while achieving the required high temperatures for calcination and cementitious material production.
Solution Approach 2:
The patent introduces heating elements as an intermediary between the electrical energy source and the raw materials. These heating elements serve as a heat transfer medium that directly contacts the material bed, enabling efficient heat transfer without the need for combustion gases. This intermediary approach solves both the CO2 emission problem and the heat transfer efficiency issue.
2Temperature
If batch-wise heat treatment is used, then heating can be performed, but productivity is low and continuous processing is not achieved
Solution Approach 1:
The patent implements a continuous heat treatment process where raw materials are continuously fed into the reactor, continuously conveyed through the heating zone, and continuously discharged as heat-treated material. The conveyor system maintains constant motion, ensuring uninterrupted heating operation. This continuous process dramatically improves productivity compared to batch-wise treatment while maintaining effective heat transfer through direct contact between the heating elements and the moving material bed.
3Device complexity
If stationary material bed heating is used, then heating structure is simple, but heat transfer efficiency is poor and temperature uniformity is achieved
Solution Approach 1:
The patent introduces dynamic motion to the material bed through a conveyor system that continuously moves the materials through the heating zone. The conveyor creates relative motion between the heating elements and the material, enhancing heat transfer efficiency through continuous contact renewal. This dynamic approach maintains relatively simple heating structure while dramatically improving heat transfer performance and temperature uniformity throughout the material bed.
4Productivity
If conveying speed is increased, then productivity improves, but residence time decreases and temperature achievement is compromised
Solution Approach 1:
The patent employs adjustable conveyor speed as a controllable parameter to optimize the balance between productivity and temperature achievement. By varying the conveying speed, the system can adjust the residence time of materials in the heating zone. Faster speeds increase productivity with reduced residence time, while slower speeds ensure complete heat treatment. This parameter adjustment capability allows flexible optimization based on production requirements and material characteristics.
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 enables efficient, continuous heat treatment of raw materials up to 1200°C, reduces CO2 emissions by eliminating fossil fuel combustion, and extends the lifespan of heating elements by avoiding high-temperature contact, while allowing for flexible material processing and CO2 utilization.
Implementation Method 1
applying radiative heating to the material bed from above and/or from the sides, wherein said radiative heating preferably contributes at least 60%, preferably at least 80% of the thermal energy needed for said heating step
Data Source
AI summary
A method of heating solids in a reactor to produce a heat-treated material, such as a cementitious, a supplementary cementitious, or a pozzolanic material, includes conveying the solids through the reactor from a feeding end to a discharge end so as to form a material bed extending from the feeding end to the discharge end; heating the solids during the conveying to at least 600° C. to transform the solids into the heat-treated material, wherein the heating includes applying radiative heating to the material bed from above and/or from the sides, wherein the radiative heating contributes at least 60% of the thermal energy needed for the heating, and wherein the material bed is mobilized during the conveying in order to renew the surface of the material bed that is exposed to the radiative heating.