Rolling Mill Cooling Pressure Control With VFD Pumps and Isolation Valves
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Solution Overview
Problem
Current temperature control systems in rolling mills lack precise control over cooling pressure and flow, leading to inefficiencies in metallurgical property transition and product quality, as they rely on operator-defined recipes and fixed-speed pumps, which result in suboptimal cooling efficiency and potential formation of undesirable steel allotropes like martensite.
Innovation Solution
The implementation of a temperature control system with isolation valves mounted close to cooling nozzles and Variable Frequency Drive (VFD) pumps, which allows for more precise control of cooling length and pressure, reducing transition time and energy consumption by adjusting supply pressure dynamically based on processing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If fixed-speed pumps are used to supply cooling water, then the system is simple and reliable, but the cooling pressure cannot be dynamically adjusted to match changing processing conditions, resulting in suboptimal cooling efficiency and potential formation of undesirable steel allotropes
Solution Approach 1:
The patent applies dynamics by replacing fixed-speed pumps with variable speed pumps that can dynamically adjust their operating parameters. The control system continuously monitors processing conditions (product speed, temperature, metallurgical requirements) and automatically adjusts pump speed and water box flow rates in real-time, transforming a static system into a dynamic one that adapts to changing conditions optimally
Solution Approach 2:
The control system implements self-service by automatically sensing processing conditions and adjusting cooling parameters without operator intervention. The system uses feedback from sensors monitoring product speed, temperature, and pump performance to autonomously optimize cooling water flow and pressure, eliminating the need for manual recipe changes or operator adjustments
2Manufacturing precision
If operator-defined recipes are used for temperature control, then the system is easy to operate, but it lacks precise control over cooling pressure and flow, leading to inefficiencies in metallurgical property transition and product quality
Solution Approach 1:
The patent implements feedback control by continuously monitoring actual cooling performance and processing conditions, then using this information to automatically adjust water box flow rates and pump speeds. Sensors measure product temperature, cooling water pressure and flow, and feed this data back to the control system, which makes real-time corrections to maintain optimal cooling conditions and achieve precise metallurgical outcomes
Solution Approach 2:
The system replaces manual mechanical control (operator-defined recipes and manual adjustments) with automated electronic control. The control system uses electronic sensors, processors, and actuators to precisely regulate cooling parameters, substituting human judgment and manual valve adjustments with automated electronic control that achieves superior precision and consistency
3Productivity
If water pressure is increased to improve cooling effectiveness, then cooling efficiency improves, but the product surface may be over-quenched and undesirable martensite can form
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting multiple cooling parameters (water pressure, flow rate, water temperature) in combination rather than changing single parameters in isolation. The control system modifies these parameters based on real-time processing conditions to achieve optimal cooling rates that improve efficiency while preventing martensite formation through controlled cooling curves
4Stress or pressure
If large fixed-speed pumps are used to provide total flow for the entire mill, then the system is simple, but the pressure is relatively low (~2 bar) and cannot meet the requirements of high-speed rolling equipment that needs higher pressure
Solution Approach 1:
The patent applies segmentation by dividing the water supply system into separate zones or circuits, each with its own variable speed pump optimized for specific pressure and flow requirements. Instead of one large pump serving all equipment, the system uses multiple smaller pumps that can be independently controlled, allowing high-pressure delivery to high-speed rolling equipment while maintaining simple overall system architecture
Solution Approach 2:
The variable speed pumps provide multi-functionality by being capable of delivering a wide range of pressures and flow rates to satisfy diverse equipment requirements. A single pump design can serve multiple functions by adjusting speed, eliminating the need for separate fixed-speed pumps for different pressure requirements and reducing overall system complexity
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 enhances the uniformity of metallurgical properties and reduces the transition length, improving cooling efficiency and product quality by minimizing lag time to achieve set point temperatures and maintaining stable pressure, thus preventing martensite formation and optimizing energy use.
Implementation Method 1
The implementation of a temperature control system with isolation valves mounted close to cooling nozzles and Variable Frequency Drive (VFD) pumps, which allows for more precise control of cooling length and pressure
Implementation Method 2
a spray header for cooling a strip or a roll in a rolling mill, the spray header comprising plural spray nozzles
Implementation Method 3
When the water pressure is less than a minimum pressure (~0.5 bar); the product cooling is not effective in penetrating the steam jacket (created by the Leidenfrost effect) and cooling the product
Implementation Method 4
Isolation valves are mounted to the waterbox or within close proximity of the cooling nozzle. Each isolation valve is associated with a single cooling nozzle
Data Source
Figure 1
Figure 1
Figure 1
AI summary
A temperature control system (2) used for cooling a rolling mill product is provided. The temperature control system (2) includes a plurality of isolation valves (4) that are directly coupled to one or more water boxes (6). At least one pump is coupled to the isolation valves (4). The at least one pump provides the pressure needed for cooling. The isolation valves (4) are positioned to reduce the time required to build up pressure for cooling and reducing the metallurgical property transition length of the rolling mill product.