Ceramic-Coated Heating Rolls for Compact Aluminium Strip Annealing
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Solution Overview
Problem
Current continuous heat treatment equipment for aluminum strips is limited by slow heat-up speed, long and costly equipment, and surface deformation issues during annealing or solution heat treatment, leading to inefficient processing and potential defects.
Innovation Solution
A compact method and apparatus using rotating heating rolls with ceramic coatings to rapidly heat and treat aluminum alloy strips, allowing direct contact for efficient heat transfer and minimizing deformation, combined with rapid cooling rolls for homogeneous quenching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If forced air is used to suspend and heat the aluminium strip, then the strip can be kept without contact with equipment, but the heat-up speed is slow and the processing line becomes very long
Solution Approach 1:
A ceramic coating layer is applied as an intermediary between the heating roll and the aluminium strip. This coating allows efficient thermal contact while preventing direct metal-to-metal contact that would cause surface defects. The ceramic layer acts as a mediator that enables both heat transfer and surface protection simultaneously.
Solution Approach 2:
The patent replaces the forced air suspension system with a direct contact heating system using ceramic-coated rolls. This substitution eliminates the need for complex air suspension mechanisms and achieves much faster heat-up speeds through direct thermal conduction while the ceramic coating prevents surface damage.
2Object-affected harmful factors
If forced air is used to suspend the aluminium strip, then contact with equipment is avoided, but the processing line length reaches up to 800 meters or longer
Solution Approach 1:
The ceramic coating serves as an intermediary that enables direct contact heating without surface damage. This allows the processing line to be compact by using direct contact rolls instead of requiring an 800-meter long air suspension system, dramatically reducing the overall equipment footprint.
Solution Approach 2:
The patent combines multiple functions into the ceramic-coated heating rolls: heating, surface protection, and strip support are all achieved through direct contact with the coated rolls. This merging of functions eliminates the need for separate suspension and heating systems, reducing the processing line length from 800 meters to a compact configuration.
3Speed
If direct contact heating is used with ceramic-coated rolls, then heat-up speed increases significantly, but the equipment requires ceramic coating application
Solution Approach 1:
The patent changes the surface parameter of the heating rolls by applying a ceramic coating. This modification enables direct contact heating with high heat-up speed while the ceramic material provides the necessary non-stick and protective properties. The coating process is a standard industrial technique that makes the solution manufacturable.
4Productivity
If traditional continuous processing line is used, then high volume throughput is achieved, but the equipment is expensive and occupies very large building space
Solution Approach 1:
The patent merges the heating, cooling, and strip support functions into a compact sequence of ceramic-coated rolls. This integration eliminates the need for separate long heating sections and air suspension systems, achieving high throughput in a compact footprint that occupies minimal building space compared to traditional 800-meter processing lines.
Solution Approach 2:
The patent replaces the complex forced air suspension and heating system with direct contact ceramic-coated rolls. This substitution achieves comparable or superior throughput while dramatically reducing the equipment footprint and building space requirements, making the process both productive and space-efficient.
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 significantly reduces heat-up time, improves grain recrystallization, and minimizes surface defects, enabling faster, more efficient, and cost-effective heat treatment with reduced equipment size and deformation issues.
Implementation Method 1
a surface of the aluminium alloy strip is in heat-transfer contact with a part of the outer-surface of the heating roll to induce heat into the aluminium alloy strip
Implementation Method 2
the outer-surface of the heating rolls is coated with a ceramic coating selected from the group consisting of titanium nitride, tungsten carbide, and chromium nitride
Implementation Method 3
a surface of the aluminium strip is in heat-transfer contact with the outer-surface of the rotating cooling rolls to remove heat from the aluminium strip and to cool the aluminium strip to a temperature below about 100°C
Data Source
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AI summary
The invention relates to a method for the heat treatment of a moving aluminium alloy strip, the aluminium strip has an upper-surface and a lower-surface, the method comprising moving the aluminium strip over at least two rotating heating rolls, wherein the heating rolls comprises an outer-surface, such that a surface of the aluminium strip is in heat-transfer contact with the outer-surface of the heating rolls to induce heat into the aluminium strip to heat the aluminium strip at an annealing temperature, and comprising moving the aluminium alloy strip over a first rotating heating roll followed by moving the aluminium strip over a second rotating heating roll such that alternating the upper-surface and the lower-surface of the aluminium strip are in heat-transfer contact with the outer-surface of the rotating heating rolls.