Grooved Forming Roll Uniform Water Flow
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Solution Overview
Problem
Existing grooved forming rolls face issues with web marking and are prone to damage due to uneven water flow and large necks between openings, which are difficult to machine and maintain, leading to inefficiencies and fabric wear.
Innovation Solution
The use of circular grooves positioned and dimensioned to create uniform flow connections between openings, resulting in a larger open surface area with narrow necks, ensuring uniform water flow and minimizing marking, while being easy to manufacture and maintain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spiral grooves are machined obliquely to create flow connections between openings, then flow connection is achieved, but the necks become indefinite in form and size making the surface sensitive to damaging and depleting the fabric
Solution Approach 1:
The invention segments the continuous spiral groove into discrete circular grooves positioned at specific intervals. Each circular groove creates a defined flow connection between adjacent openings while maintaining sharp, well-formed necks. This segmentation provides both the necessary flow paths and structurally robust neck regions that resist damage and minimize fabric wear.
Solution Approach 2:
The circular grooves are positioned and dimensioned to create locally optimized flow connections. The grooves have specific radii and spacing that ensure uniform neck formation in critical areas. This local quality control ensures that necks maintain consistent, damage-resistant dimensions throughout the roll surface while enabling effective water flow between openings.
2Ease of manufacture
If circular grooves are used instead of spiral grooves for easier machining, then manufacturing is simplified, but the remaining necks are large and flow between adjacent openings is poor causing marking problems
Solution Approach 1:
The circular groove design serves multiple functions simultaneously: it provides easy machining through standard circular groove tools, creates uniformly sized necks through consistent geometric definition, and enables adequate water flow through optimized groove spacing and dimensions. This multi-functionality resolves the contradiction between manufacturing simplicity and flow performance.
Solution Approach 2:
The invention optimizes specific parameters of the circular grooves including radius, spacing, and depth to achieve the desired balance. By carefully selecting these parameters, the design ensures that necks are neither too large (which would cause poor flow and marking) nor too small (which would compromise structural integrity). The parameters are tuned to enable both ease of manufacture and adequate flow performance.
3Adaptability or versatility
If a drilled shell without wire net is used to avoid wire net problems, then wire net restrictions are eliminated, but clear marking is created in the web due to vacuum and outer fabric effects
Solution Approach 1:
The forming roll shell is designed with a porous structure consisting of numerous small openings distributed across the surface. This porous configuration allows uniform vacuum distribution and water flow throughout the web contact area, eliminating the marking problems associated with both wire nets and drilled shells. The porous structure provides the necessary flow paths while maintaining even pressure distribution across the web.
4Productivity
If large open surface area is provided for the roll, then dewatering capacity is increased, but necks between openings become larger causing non-uniform water flow and marking
Solution Approach 1:
The open surface area is segmented into numerous small openings rather than a few large ones. This segmentation allows the roll to provide large total open area for high dewatering capacity while maintaining small, uniform necks between openings. The segmented structure ensures uniform water flow distribution across the entire roll surface, preventing marking while maximizing productivity.
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 design achieves uniform dewatering across the roll area, reduces marking, and enhances the roll's resistance and longevity by ensuring a smooth, uniform water flow mainly in the radial direction, while being economical and easy to manufacture.
Implementation Method 1
circular grooves formed on the outer surface, arranged concentrically relative to the corresponding opening, and on which outer surface a portion of the formed circular grooves extends to each opening from each adjacent opening
Implementation Method 2
the effect of vacuum and/or the outer fabric during web forming
Data Source
AI summary
A grooved forming roll in a paper machine has a rotably supported shell (20) with circular openings (21) arranged to be open at least on the outer surface of the shell (20). Each opening (21) has a circular groove which is formed on the outer surface and which is arranged concentrically relative to the opening (21). A portion of the formed circular openings (22) extends to each opening (21) from each adjacent opening (21). The outer radius (r) of the circular groove (22) is arranged such that the number of necks (24), delimited by the adjacent openings (21) and their circular grooves (22) on the shell outer surface within the area of one circular groove (22), is greater than the number of the adjacent openings (21) of the corresponding opening (21).