Suction-Controlled Guide Roller for Press Section Web Travel
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Solution Overview
Problem
High-speed web separation in paper or tissue production is inefficient due to expensive suction felt guide rolls, which require complex rotary drives and high operational costs, making reliable web travel challenging.
Innovation Solution
A suction-controlled guide roller with its own drive and a simple, fixed suction box is used after the first press nip, allowing for reliable web guidance with reduced effort, and the guide roller's drive power compensates for friction losses, while the suction element is designed with multiple zones and a large wrap angle to maintain belt tension.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a suction felt guide roll with rotary drive is used for web separation, then reliable web travel is achieved, but device complexity and operational costs increase significantly
Solution Approach 1:
The press section is divided into multiple press nips with different suction requirements. The first press nip uses a rotary suction guide roll for high-speed operation, while subsequent press nips use simpler stationary suction boxes, segmenting the complexity across different functional zones
Solution Approach 2:
Different suction elements are applied at different locations along the press section. The rotary suction guide roll is used specifically where high-speed web separation is critical, while stationary suction boxes are used where lower speeds allow simpler design
2Stability of the object's composition
If a rotary drive is added to the suction guide roll to maintain belt tension, then web run stability improves, but energy consumption and device complexity increase
Solution Approach 1:
The suction guide roll is given its own rotary drive to dynamically maintain belt tension during high-speed operation. This dynamic adjustment allows the system to adapt to varying operational conditions while maintaining stability
Solution Approach 2:
The suction guide roll's own drive serves dual purposes: it maintains belt tension and drives the suction function, making the component self-sufficient and reducing the need for separate tensioning mechanisms
3Stability of the object's composition
If the suction guide roll is positioned on the drive side with eccentric gear, then belt tension is maintained, but device complexity and manufacturing costs increase
Solution Approach 1:
The suction guide roll is positioned asymmetrically on the drive side with an eccentric gear arrangement, creating intentional asymmetry in the mechanical layout to achieve belt tension maintenance through the rotational motion
4Productivity
If machine speed is increased above 1100 m/min, then productivity improves, but web separation becomes unreliable with conventional suction separators
Solution Approach 1:
The suction guide roll is positioned to act on the web before it enters subsequent press nips, performing web stabilization in advance at high speed, allowing the web to be properly prepared for further processing
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 configuration ensures stable web travel at high speeds and reduces operational costs by eliminating the need for complex rotary drives and expensive suction felt guide rolls, maintaining web integrity and tension effectively.
Implementation Method 1
a suction element after the first press nip is formed by a rotating guide roller with suction
Data Source
Figure 1
AI summary
The invention relates to a press section of a machine for producing a fibrous web (1), in particular a paper, cardboard or tissue web, having two press nips (3, 4) which lie behind one another in the web running direction (2) and are formed by in each case two press elements, wherein at least one separate, endlessly circulating press belt (5, 6, 7, 8) is guided around each press element in each case via a plurality of guide rollers (9), the fibrous web (1) runs together with two press belts (5, 6, 7, 8) which lie opposite one another in each case over a guide section (10, 11) downstream of the press nips (3, 4), and one belt (5, 7) is guided away from the fibrous web (1) downstream of the guide section (10, 11) which in each case follows a press nip (3, 4), whereas the opposite belt (6, 8) runs along a suction element (14, 15) together with the fibrous web (1). Here, secure web running is to be made possible with as little complexity as possible by virtue of the fact that the suction element (14) is formed by a rotating, evacuated guide roller downstream of the first press nip (3) and is formed by a stationary suction box downstream of the second press nip (4).