Dryer Roller Chemical Spraying for Paper Adhesion Control
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Solution Overview
Problem
Existing methods for spraying a chemical solution onto a dryer roller in paper-making machines are ineffective in preventing adhesion of paper powder or pitch due to absorption by wet paper, especially at high rotational speeds, leading to contamination and insufficient chemical solution coverage.
Innovation Solution
A method involving two nozzle devices reciprocating along the width direction of the dryer roller, with specific settings for travel time, rotational speed, and number of contacts to ensure a sufficient chemical solution amount remains on the roller surface, including adjusting the travel distance, moving speed, and spray width to maintain an effective chemical solution layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the dryer roller rotates at high speed to match the transportation speed of wet paper, then productivity is improved, but the chemical solution is absorbed by wet paper multiple times leading to insufficient coverage and contamination
Solution Approach 1:
The chemical solution is sprayed onto the dryer roller surface in advance before the wet paper makes contact. This preliminary application ensures that the anti-soiling agent is already positioned on the roller surface to prevent adhesion of paper powder and pitch, countering the absorption issue by establishing protective coverage before the problematic contact occurs
Solution Approach 2:
The spraying system operates continuously to maintain a sufficient layer of chemical solution on the dryer roller surface throughout the high-speed rotation. This continuous application compensates for the repeated absorption events, ensuring that fresh chemical solution is constantly replenished on the roller surface to maintain effective coverage
2Device complexity
If a single nozzle device is used to spray chemical solution, then device complexity is reduced, but the travel distance increases causing insufficient chemical solution application at high speeds
Solution Approach 1:
The single spraying task is divided between two nozzle devices, each responsible for a specific section of the dryer roller circumference. This segmentation reduces the travel distance each nozzle must cover, allowing them to apply chemical solution more effectively and maintain sufficient coverage even at high rotational speeds
Solution Approach 2:
Instead of having one nozzle traverse the entire roller circumference, two nozzles are positioned at different angular locations around the roller. This spatial arrangement in another dimension (angular position) allows simultaneous coverage of different sections, effectively doubling the coverage rate without increasing individual nozzle travel distance
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 ensures a stable and uniform application of the chemical solution, preventing adhesion of paper powder or pitch, maintaining a sufficient solution layer on the dryer roller even at high speeds, thus enhancing productivity and reducing contamination, and allowing for cost-effective paper production.
Implementation Method 1
spraying a chemical solution onto a dryer roller with a nozzle device reciprocated in a width direction of the dryer roller
Implementation Method 2
the chemical solution given to a surface of the dryer roller is partially absorbed by the wet paper
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
To provide a method for spraying a chemical solution, including: spraying the chemical solution onto a surface of a dryer roller with a nozzle device reciprocated in the width direction of the dryer roller rotating at a high speed, whereby a sufficient amount of the chemical solution can be remained on the surface of the dryer roller. [Solution] The present invention is directed to a method for spraying a chemical solution, including: spraying the chemical solution onto a dryer roller (D1) by two nozzle devices (S) disposed at a certain interval therebetween with the two nozzle devices (S) each reciprocated along a rail (L) extended in the width direction of the dryer roller (D1), in a state that the dryer roller (D1), for guiding wet paper (X), is being rotated, in a dry part (DP) of a paper-making machine, wherein a time T required for the two nozzle devices (S) each to travel one-way is set as 0.2 to 1.5 minutes; a rotational speed Vd of the dryer roller (D1) is set as not less than 100 times/min; the number of contacts N that a point Q on the dryer roller (D1) surface makes contact with the wet paper (X) during the time T is set as 30 to 250 times; the time T, the rotational speed Vd, and the number of contacts N satisfy the relationship of N=T∗Vd; and the total amount of the sprayed chemical solution is set as 0.3 to 500 mg/m2 as an effective component amount.