Stripper Shielding for Hot Rolling Stand Thermal Stress
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In roll stands, particularly hot rolling stands, strippers for work rolls face high thermal stress due to contact with rolling stock, leading to uneven thermal expansion and potential buckling, which compromises the sealing effectiveness and longevity of the scraper.
Innovation Solution
A scraper design featuring a first shielding element to prevent cooling water from reaching the rolling stock and a second shielding element to protect the first from thermal stress, spaced apart to manage thermal expansion, with an insulating element in between to prevent excessive heat deformation, forming a sandwich structure for stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the scraper is positioned close to the roll gap to cool the work roll quickly, then the cooling effectiveness is improved, but the scraper is exposed to high thermal load from the rolling stock
Solution Approach 1:
The scraper is divided into multiple segments along its length, with each segment independently adjustable. This allows the scraper to be positioned close to the roll gap for effective cooling while managing thermal expansion through segmental adjustment mechanisms
Solution Approach 2:
The scraper incorporates dynamic adjustment capabilities that allow real-time modification of the scraper's position and contact pressure with the work roll. This enables adaptation to thermal expansion during operation, maintaining sealing effectiveness despite temperature variations
2Reliability
If the scraper is pressed against the work roll with high force to maintain sealing, then the sealing effectiveness is improved, but the scraper is more susceptible to thermal deformation
Solution Approach 1:
The scraper uses dynamically adjustable pressing mechanisms that can modify contact force in response to thermal conditions. This maintains adequate sealing pressure while reducing excessive force that would accelerate thermal deformation
Solution Approach 2:
The scraper design incorporates parameters such as contact pressure, position, and material properties that can be changed in response to thermal loading. This allows optimization of sealing effectiveness while managing structural stability under varying thermal conditions
3Temperature
If the scraper is made of heat-resistant material to withstand thermal load, then the thermal resistance is improved, but the sealing precision against cooling water may be compromised
Solution Approach 1:
The scraper is segmented with different material properties along its length - the portion exposed to high heat uses heat-resistant material, while the sealing portion uses materials optimized for precision sealing against cooling water
Solution Approach 2:
Different regions of the scraper have different material compositions and properties tailored to their specific functions. The heat-exposed regions use thermally stable materials, while the sealing regions use materials with superior sealing 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 design ensures consistent contact with the work roll, prevents buckling, and maintains effective sealing, allowing for controlled adjustment and prolonged scraper lifespan by mitigating thermal stress and heat penetration.
Implementation Method 1
an insulating element for thermally isolating the two shielding elements from one another is arranged between the first shielding element and the second shielding element
Implementation Method 2
a second shielding element for shielding the first shielding element against thermal stress from the rolling stock
Implementation Method 3
The scrapers are designed to shield the surface of the rolling stock from the roll cooling water and are able to strip off any rolling stock adhering to the working rolls from the working rolls
Data Source
Figure 1
AI summary
The present invention relates to a stripper (11) for an operating roll of a rolling stand, in particular a hot-rolling stand, wherein the stripper (11) has a stripper tip (5) for making contact with an operating roll (1) of the rolling stand and a first screening element (8) for screening the material (10) being rolled against cooling water of the rolling stand is provided, wherein a second screening element (6) for screening the first screening element (8) against a thermal loading by the material (10) being rolled is provided.