Grooved Turn Roll Clogging Prevention via Suction Hole Geometry

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Solution Overview

Problem

Existing turn rolls in fiber web machines face issues with clogging due to fine-grained and sticky materials, leading to inefficient suction, high energy consumption, and costly manufacturing, with deep grooves and small suction holes being prone to soiling and clogging.

Innovation Solution

A grooved and perforated turn roll design with suction holes having an open area at least two times larger than the groove cross-sectional area, a changed drill pattern with larger holes at longer intervals, and grooves spaced 2 to 4 times the diameter of the suction holes, along with a smooth, cornerless groove profile and chamfer, to enhance suction efficiency and prevent clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If small suction holes are used in deep grooves, then suction effect is improved, but clogging by fine-grained and sticky materials occurs

Engineering Contradiction:
Improvesuction effectVSAvoidclogging
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the dimensional parameters of suction holes and grooves: suction holes have a diameter of 2-5 mm (larger than conventional), grooves have a depth of 1-3 mm (shallower than conventional) and width of 5-15 mm. This parameter optimization prevents clogging while maintaining suction effectiveness by reducing the accumulation of fine-grained and sticky materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The groove profile features rounded corners and curved transitions instead of sharp angles. The groove has a curved bottom and sloped sides, creating a smooth geometry that prevents material accumulation and facilitates easier cleaning, thereby reducing clogging while maintaining structural integrity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Reliability

If deep square grooves are used, then suction capacity is increased, but manufacturing cost and time increase

Engineering Contradiction:
Improvesuction capacityVSAvoidmanufacturing cost and time
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The groove profile uses curved surfaces and rounded transitions throughout, eliminating sharp corners and flat sections that are difficult to manufacture. The curved groove geometry can be more efficiently produced using standard machining operations, reducing manufacturing time and cost while maintaining adequate suction capacity.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent optimizes groove dimensions to shallower depth (1-3 mm) and greater width (5-15 mm) compared to conventional deep square grooves. This dimensional change reduces the amount of material removal required and simplifies manufacturing while providing sufficient suction capacity through the optimized geometry.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If many suction holes are provided, then suction effect is improved, but air volume consumption increases

Engineering Contradiction:
Improvesuction effectVSAvoidair volume consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the parameters of individual suction holes to larger diameter (2-5 mm) and optimized spacing. This reduces the total number of holes needed while maintaining effective suction coverage, thereby reducing the overall air volume consumption while preserving suction performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of providing maximum possible suction holes, the patent uses a partial set of larger, optimally spaced holes that provide sufficient suction effect. This partial action approach avoids the excessive air volume consumption associated with dense arrays of small holes while maintaining adequate suction performance.

Inventive Principle:
Principle #16Partial or excessive action

4Adaptability or versatility

If recycled paper is used as raw material, then sustainability is improved, but dryer section soiling increases

Engineering Contradiction:
ImprovesustainabilityVSAvoiddryer section soiling
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The rounded groove profile with curved surfaces prevents the accumulation of sticky materials and fine particles that cause soiling. The smooth geometry allows for easier cleaning and reduces the adhesion of recycled paper residues, thereby reducing dryer section soiling while maintaining sustainability benefits.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The optimized groove dimensions (shallower depth, greater width) and suction hole parameters reduce the surface area where soiling can occur and improve airflow that prevents material accumulation. This reduces the impact of recycled paper soiling while maintaining the sustainability advantage of using recycled materials.

Inventive Principle:
Principle #35Parameter changes

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

The new design prevents clogging, achieves a more uniform and efficient suction effect with reduced air volume, reduces manufacturing time and costs, and allows for a thinner shell, resulting in improved runnability and reduced energy consumption.

Implementation Method 1

a suction effect created with a turn roll makes it possible to keep the fiber web and the threading tail cut therefrom, when necessary, attached to the dryer fabric

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 2

A turn roll is also called a turn suction roll, a vacuum roll or a VacRoll

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3803242B1Grooved and perforated turn roll of a fiber web machine
Publication Date: 2023.01.11 VALMET TECH OY
  • EP3803242B1 patent drawingFigure 1a~1b
  • EP3803242B1 patent drawingFigure 2a~2b
  • EP3803242B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a grooved and perforated turn roll of a fiber web machine. The turn roll (12) includes a shell (20) and grooves (22) formed on the surface (21) of the shell (20). Suction holes (23) extending through the shell (20) are provided on the bottom (24) of the groove (22) in the inward area of the edges (27). The open area (AR) of the suction hole (23) is at least two times larger than the cross-sectional area (Au) of the groove (22). In addition, the bottom (24) of the groove (22) has at least one radius of curvature (R), the center of curvature (28) of which is outside the groove (22).