Suction Roll Hole Pattern for Larger Open Area and Plugging Resistance
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Solution Overview
Problem
Existing suction rolls in papermaking machines face challenges with hole plugging and limited performance due to restrictive land distance between holes, which affects their efficiency and durability in high-load and corrosive environments.
Innovation Solution
A pattern of through and blind drilled holes in the polymeric cover of suction rolls, arranged at specific angles and offsets, allowing for larger hole sizes and improved open area, reducing plugging and enhancing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a grid-like pattern of holes is formed in the polymeric cover, then manufacturing efficiency is improved, but hole size is limited due to restrictive land distance
Solution Approach 1:
The hole pattern is segmented into two distinct types: through holes that extend completely through the polymeric cover and blind drilled holes that terminate before penetrating the full thickness. This segmentation allows each hole type to be optimized independently - through holes can be larger for better suction while blind holes provide drainage functionality without compromising structural integrity.
Solution Approach 2:
The patent transitions from a conventional two-dimensional grid pattern to a three-dimensional hole distribution system. Through holes are positioned at specific locations while blind drilled holes are arranged in offset rows at different depths, creating a multi-layered hole structure that increases effective open area without reducing land distance between holes on the surface.
2Quantity of substance
If hole size is increased to improve suction performance, then open area is improved, but land distance between holes becomes restrictive
Solution Approach 1:
The blind drilled holes are nested within the polymeric cover structure at positions that do not interfere with the through holes. The blind holes are drilled to a depth that allows them to function for drainage while maintaining adequate land distance from the through holes, effectively nesting two functional systems within the same cover volume.
Solution Approach 2:
Different regions of the polymeric cover are assigned different hole characteristics - through holes are created in areas requiring primary suction function with larger diameters, while blind drilled holes are positioned in regions where drainage is prioritized. This local differentiation allows optimization of hole size and land distance for each functional zone.
3Ease of manufacture
If through holes are arranged in oblique rows and columns, then manufacturing is simplified, but plugging resistance is reduced
Solution Approach 1:
The blind drilled holes are arranged in offset rows that are asymmetrically positioned relative to the through hole grid pattern. This asymmetric arrangement prevents the formation of continuous straight lines of holes that are prone to plugging, while still maintaining manufacturability through systematic drilling patterns. The offset positioning creates a more complex but plugging-resistant hole distribution.
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 hole pattern increases hole sizes, reduces plugging, and improves the roll's performance and durability by increasing the open area, making it more efficient and resistant to plugging.
Implementation Method 1
Vacuum pressure is applied with a suction box located in the interior of the suction roll shell. Water is drawn into the radially-extending holes
Implementation Method 2
Water is drawn into the radially-extending holes and is either propelled centrifugally from the holes after they pass out of the suction zone
Data Source
Figure 1~3
AI summary
A cylindrical polymeric cover for an industrial roll includes a plurality of through holes and a plurality of blind drilled holes. The through holes and the blind drilled holes are arranged in a pattern in which: (a) the through holes are arranged in rows that define an oblique angle relative to a plane that is perpendicular to a longitudinal axis of the cover; (b) the through holes of one row are offset from the through holes of the adjacent row, with the offset between rows defining an angle of approximately 20-40 degrees; (c) the blind drilled holes are arranged in rows located between the rows of through holes; (d) the blind drilled holes of one row are offset slightly from the blind drilled holes of the adjacent row, with the offset between rows defining an angle similar to that defined by the through holes; and (e) each of the blind drilled holes is located at the substantial center of a triangle defined by the closest three through holes.