Multistage Rolling Mill Layout for Work Roll Support and Cooling
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Solution Overview
Problem
Conventional six-high rolling mills face challenges in supporting small-diameter work rolls due to space constraints, leading to increased driving tangential force, shortened bearing life, and risk of support pad wear during high-load events like strip breakage, which hinders efficient rolling of hard materials and affects product quality.
Innovation Solution
A multistage rolling mill design featuring a pair of work rolls, intermediate rolls, and back-up rolls, with adjustable support roll groups and coolant spray headers, allowing for offset positions of support bearings and intermediate rolls to reduce horizontal forces and enable effective cooling and water removal, while using tapered roll shoulders and shift devices to manage roll axis alignment and load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If support bearings and support pads are provided to support the work rolls over the entire length in the strip width direction, then the work rolls are adequately supported, but there is no space for installing coolant spray headers, cobble guards, and for controlling coolant zone flow rates
Solution Approach 1:
The support function is segmented into two distinct systems: support bearings arranged at discrete positions (entry side and/or exit side) to provide adequate structural support, and a centralized strip support structure (chocks positioned in the strip width direction central portion) to support the strip during processing. This segmentation frees up the entry and exit sides for installing coolant spray headers and cobble guards without compromising work roll support stability.
2Productivity
If rolling torque is increased to improve productivity, then the driving tangential force produced by intermediate roll driving is increased, but the horizontal force applied to the work rolls is increased, shortening the life of the support bearings
Solution Approach 1:
The patent introduces an intermediate support mechanism (chocks positioned in the strip width direction central portion) that acts as a mediator between the work rolls and the support structure. This intermediate support shares the load during high-torque operations, reducing the horizontal force transmitted to the support bearings and extending their operational life while maintaining high productivity.
3Reliability
If fixed support pads are provided on the entry side or exit side of the work rolls, then the work rolls are supported, but an instantaneous high load may be applied to the fixed support pads during strip breakage, causing great wear
Solution Approach 1:
The support system transitions from fixed support pads to movable/detachable chocks positioned in the strip width direction central portion. These dynamic support elements can be adjusted or removed as needed, allowing the system to adapt to varying load conditions and preventing excessive wear during instantaneous high-load events like strip breakage, while maintaining work roll support stability during normal operation.
Data Source
AI summary
A multistage rolling mill 100 includes support bearings 10a, 10b, 10c, 10d, 10e, 10f, 10g, and 10h arranged on the entry side and/or the exit side of work rolls 2a and 2b, and supporting the work rolls 2a and 2b on an work side and a drive side. The offset positions in a pass direction of the pair of work rolls 2a and 2b for rolling a strip 1 are changed by moving in and out the support bearings 10a, 10b, 10c, 10d, 10e, 10f, 10g, and 10h to the entry side or the exit side with respect to the pass direction. A multistage rolling mill capable of rolling a hard material efficiently and suitable for obtaining a strip of high product quality is thereby provided.