Shifting Mill Roll Profile for Long ESP Rolling and Wear Control

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Solution Overview

Problem

Current rolling mills used in ESP production lines have limited rolling kilometres due to roll wear, leading to edge contact and reduced geometric properties of the rolled product, with existing roll profiles resulting in less than 80 km of uninterrupted rolling.

Innovation Solution

The rolling mill features frustum-shaped and cylindrical ends with a cosine or polynomial roll profile, allowing for horizontal shifting of rolls to compensate for wear, maintaining constant roll gap and product thickness through hydraulic and electric adjustments, and utilizing a wear monitor to optimize roll shifting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If cosine concave roll profile is used, then initial rolling capability is good, but roll wear increases and edge contact occurs after 80 km

Engineering Contradiction:
Improvegeometric properties of rolled productVSAvoidrolling kilometres
Core Design Contradiction:
Manufacturing precisionVSDuration of action of moving object

Solution Approach 1:

The invention applies a dynamic roll profile that changes during operation. The roll surface is divided into multiple zones with different profile characteristics (cosine concave in the middle, frustum-shaped at ends). As the roll wears during rolling, the effective contact zone shifts from the middle toward the ends, maintaining optimal rolling conditions throughout the extended service life of 150 km.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different portions of the roll surface are given different geometric profiles tailored to specific functions. The middle portion has cosine concave profile for initial stable rolling, while the end portions have frustum-shaped profiles with specific slopes to compensate for wear and prevent edge contact during long-term operation.

Inventive Principle:
Principle #3Local quality

2Productivity

If rolling kilometres are increased to improve thin gauge proportion, then productivity increases, but roll wear causes contact and runaway of rolled product

Engineering Contradiction:
Improverolling kilometresVSAvoidstable rolling process
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The roll profile is pre-designed with frustum-shaped ends and specific slope characteristics before rolling begins. This preliminary geometric configuration anticipates the wear that will occur during extended rolling and is structured to automatically compensate for it, preventing edge contact and maintaining product stability throughout the 150 km rolling distance.

Inventive Principle:
Principle #10Preliminary action

3Duration of action of moving object

If mill rolls are shifted horizontally to compensate wear, then rolling kilometres extend to 150 km, but device complexity increases with hydraulic cylinders

Engineering Contradiction:
Improverolling kilometresVSAvoidroll shifting mechanism
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The invention employs hydraulic cylinders to achieve horizontal shifting of the rolls. This allows precise control of roll position to compensate for wear while maintaining a relatively compact and manageable system. The hydraulic mechanism enables the rolls to be shifted by the required amount (e.g., 3-5 mm) to extend rolling kilometres to 150 km.

Inventive Principle:
Principle #29Pneumatics and hydraulics

4Ease of manufacture

If roll profile is optimized to extend rolling distance, then maintenance costs reduce, but initial manufacturing precision requirements increase

Engineering Contradiction:
Improvemaintenance costsVSAvoidroll profile precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The roll profile is segmented into distinct zones: a middle portion with cosine concave profile and end portions with frustum-shaped profiles. Each segment serves a specific function during the rolling process. This segmentation allows the complex overall profile to be manufactured with reasonable precision by treating each segment separately, while still achieving the goal of extended rolling distance and reduced maintenance frequency.

Inventive Principle:
Principle #1Segmentation

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 solution extends rolling kilometres to 150 km, reduces maintenance costs, ensures consistent product quality, and maintains the geometric shape of the rolled product by preventing edge contact and adjusting for wear during the rolling process.

Implementation Method 1

One end of each roll is connected to a roll shifting hydraulic cylinder for shifting the roll in a horizontal direction

Methodology Applied
Scientific EffectHydraulic force: Hydraulic Press

Data Source

PatentEP3471901B1Mill rolls capable of rolling long kilometres for esp production line
Publication Date: 2023.08.09 ARVEDI STEEL ENG SPA
  • EP3471901B1 patent drawingFigure 1~4
  • EP3471901B1 patent drawingFigure 5~9
  • EP3471901B1 patent drawingFigure 6~8

AI summary

Mill rolls capable of rolling long kilometres used for ESP production line and a method for rolling long kilometres using the mill rolls. The mill rolls comprise rolls (3, 4), a bearing box (2) and a roll shifting hydraulic cylinder (1), wherein the middle portion of the surface of said roll sinks inwards, one end of the rolls is frustum-shaped, smaller and smaller outwards, so that the roll surface forms a compensation ramp, and the other end of the rolls is cylindrical. The upper roll (3) and the lower roll (4) have the same roll profile and are positioned in the opposite direction. The mill rolls are characterized by reduced runaway of the rolled product and a longer service life.