Reciprocating Nozzle for Uniform Chemical Spraying on Paper Machine Rollers
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Solution Overview
Problem
Existing methods for spraying anti-contamination agents on moving parts of paper-making machines, such as dryer rollers and canvases, fail to provide uniform application and are inefficient, leading to adhesion of paper powder or pitch, which contaminates the wet paper.
Innovation Solution
A method where a nozzle device reciprocates orthogonal to the moving direction of the dryer roller or canvas, with a travel distance and sprayed area relationship of 0.5≤H/W≤20, ensuring uniform application and preventing partial cuts in the membrane, thereby preventing paper powder or pitch adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a movable nozzle device is used to spray anti-contamination agent on dryer roller or canvas, then the spraying operation can be performed on moving bodies, but the application uniformity deteriorates due to speed synchronization issues
Solution Approach 1:
The nozzle device is designed to reciprocate in the width direction while moving in the traveling direction, creating a dynamic spraying pattern that adapts to the moving body's speed. The reciprocating motion allows the nozzle to cover the entire width of the dryer roller or canvas uniformly, solving the speed synchronization problem by continuously adjusting the spray coverage area.
Solution Approach 2:
The invention controls the relationship between travel distance H (distance the nozzle moves during one rotation of the moving body) and sprayed area width W by maintaining 0.5≤H/W≤20. This parameter control ensures that the nozzle covers the entire width uniformly while accounting for the moving body's speed, achieving both operational capability and application uniformity.
2Speed
If the nozzle device moves at the same speed as the wet paper, then the spraying can keep up with the moving body, but the sprayed area coverage becomes insufficient leading to gaps
Solution Approach 1:
The nozzle device adds reciprocating motion in the width direction (orthogonal to the traveling direction) to the basic forward motion. This two-dimensional motion pattern allows the nozzle to cover the entire width of the moving body while maintaining synchronization in the traveling direction, ensuring complete coverage without gaps.
Solution Approach 2:
By controlling the travel distance H to satisfy 0.5≤H/W≤20 where W is the sprayed area width, the invention optimizes the coverage parameters. This ensures that the nozzle travels the appropriate distance during one rotation to cover the full width uniformly, preventing gaps while maintaining speed synchronization.
3Area of stationary object
If the sprayed area width is increased to cover the entire moving body, then the coverage improves, but the overlap between spray passes increases causing non-uniform application
Solution Approach 1:
The invention precisely controls the travel distance H relative to sprayed area width W by maintaining 0.5≤H/W≤20. This parameter optimization ensures adequate coverage while controlling overlap, achieving uniform application. The lower bound (0.5) prevents gaps, while the upper bound (20) limits excessive overlap that would cause non-uniformity.
Data Source
AI summary
[Problem] To provide a method for spraying a chemical solution that makes it possible to uniformly apply a chemical solution onto a moving body and that exhibits excellent spraying efficiency.[Solution] The present invention is directed to a method for spraying a chemical solution in which, in a dry part D of a paper-making machine, a chemical solution is continuously sprayed onto a moving body that guides wet paper X, while a nozzle device S is reciprocating in directions orthogonal to a moving direction of the moving body with the moving body in motion, wherein: the moving body is a cylindrical dryer roller D1 or an endless canvas K1; and a travel distance H that the nozzle device S moves during a single rotation of the moving body and a width W of a sprayed area that is formed on the moving body by the nozzle device S satisfy the relationship represented by the following expression: 0.5≤H/W≤20.