Vacuum Control in Twin-Wire Forming Section

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Solution Overview

Problem

Existing methods for controlling vacuum in forming sections of fiber web production lines are complex, energy-inefficient, and often result in compromised product quality due to uneven water removal and increased energy consumption.

Innovation Solution

A method and system for automatically controlling vacuum in a forming section by scaling the vacuum of successive suction boxes uniformly, with only the set point value of the last suction box set independently, and using intelligent control systems to detect dewatering amounts and adjust vacuum levels accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If vacuum is increased to improve water removal efficiency, then dewatering performance is improved, but energy consumption increases significantly

Engineering Contradiction:
Improvewater removal efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting vacuum levels across different suction boxes based on real-time dewatering performance data. Instead of using constant high vacuum, the system modifies vacuum parameters adaptively, setting optimal vacuum levels for each suction box to achieve effective water removal while minimizing energy consumption.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements feedback control by continuously monitoring dewatering amounts at each suction box and using this information to adjust vacuum settings. The control unit receives dewatering data and automatically modifies vacuum parameters to maintain optimal dewatering efficiency while reducing unnecessary energy expenditure.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If complex control systems are used to optimize vacuum for each suction box, then dewatering control precision is improved, but device complexity increases

Engineering Contradiction:
Improvedewatering control precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the control functions of multiple suction boxes into a single integrated control unit. Instead of requiring separate complex control systems for each suction box, the invention combines their control into one unified system that manages all suction boxes collectively, reducing overall device complexity while maintaining dewatering control precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control unit is designed with multi-functionality, serving as a universal controller for all suction boxes in the forming section. This single device performs multiple functions including monitoring dewatering at different locations, calculating optimal vacuum settings, and adjusting vacuum parameters across the entire system, thereby simplifying the overall control architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If manual adjustment of vacuum settings is performed, then adaptability to different products is improved, but operator intervention time increases

Engineering Contradiction:
Improveproduct grade adaptabilityVSAvoidoperator intervention time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The system implements self-service by automatically adapting vacuum parameters to different product grades without requiring manual operator intervention. The control unit autonomously receives dewatering data, processes the information, and adjusts vacuum settings appropriate for the current product being manufactured, eliminating the need for operators to manually reconfigure settings when changing products.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system performs preliminary action by pre-calculating and setting appropriate vacuum parameters based on expected dewatering requirements for different product grades. When a product change is anticipated, the system is already prepared with appropriate vacuum settings, enabling seamless transitions without operator intervention or time loss.

Inventive Principle:
Principle #10Preliminary action

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 optimizes vacuum profiles, reduces energy consumption, improves product quality by maintaining desired dewatering levels, and minimizes operator intervention, leading to more efficient and stable fiber web production.

Implementation Method 1

a vacuum forming shoe (16A, 16B) located in the upper wire part (20) of a twin-wire part (10, 20) following the fourdrinier wire part

Methodology Applied
Scientific EffectVacuum suction: Suction

Implementation Method 2

several, successive suction boxes (15A-15E) with controllable vacuum at the first wire (10), i.e. at the fourdrinier wire (10)

Methodology Applied
Scientific EffectVacuum pressure: Vacuum

Data Source

PatentEP4516995A1Method for controlling vacuum in a forming section and a forming section with a control system for controlling vacuum of the forming section
Publication Date: 2025.03.05 VALMET TECH OY
  • EP4516995A1 patent drawingFigure 1
  • EP4516995A1 patent drawingFigure 2
  • EP4516995A1 patent drawingFigure 3

AI summary

The invention relates to a method for controlling vacuum in a forming section (200) comprising at least one forming unit (250), which forming unit (250) comprises a first wire (10) and a second wire (20) forming a twin-wire part and at least one vacuum forming shoe (16A-16C) located at the second wire (20). The method comprises steps of measuring dewatering at the at least one vacuum forming shoe (16A-16C), defining based on the measured dewatering of dewatering data information, and controlling vacuum at the at least one forming unit (250) based on the dewatering data information of the at least one vacuum forming shoe (16A-16C). The invention also relates to a forming section with a control system (100) for controlling vacuum in the forming section (200).