Drying Wire Detachment via Pneumatic Air Jet

Solution Overview

Problem

Existing paper machine technologies face challenges in efficiently detaching paper from drying cylinders due to dynamic forces and adhesive attraction, leading to issues like bending of drying wires and mechanical seal misalignment, which affect the formation of necessary pressure differences for smooth paper transfer.

Innovation Solution

An apparatus with a nozzle blowing an air jet against the drying wire's direction of travel, combined with a planar carrying surface, creates a controlled low-pressure area for paper detachment by accelerating air speed and reducing static pressure, allowing for adjustable enhanced low-pressure zones without damaging the wire.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical seals are brought close to the drying wire to achieve necessary low pressure, then paper detachment is improved, but the seal rubs against the wire and causes wear

Engineering Contradiction:

Improvepaper detachmentVSAvoidseal wear

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical sealing system with a pneumatic system. Instead of using mechanical seals that physically contact the drying wire, the invention uses a nozzle to blow air and create a low-pressure area that detaches paper. This substitution of mechanical contact with pneumatic pressure resolution eliminates wear on both the seal and the drying wire while maintaining effective paper detachment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If mechanical seals are positioned far from the drying wire to prevent contact, then wire damage is reduced, but insufficient low pressure is achieved for proper detachment

Engineering Contradiction:

Improvewire damageVSAvoidpaper detachment

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent replaces the mechanical sealing system with a pneumatic system. Instead of using mechanical seals that physically contact the drying wire, the invention uses a nozzle to blow air and create a low-pressure area that detaches paper. This substitution of mechanical contact with pneumatic pressure resolution eliminates wear on both the seal and the drying wire while maintaining effective paper detachment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If drying wire tension is increased to prevent bending, then wire stability is improved, but the wire bends more under the pressure of mechanical seals

Engineering Contradiction:

Improvewire stabilityVSAvoidwire bending

Core Design Contradiction:

Stability of the object's compositionVSShape

Solution Approach 1:

The patent replaces the mechanical sealing system with a pneumatic system. Instead of using mechanical seals that physically contact the drying wire, the invention uses a nozzle to blow air and create a low-pressure area that detaches paper. This substitution of mechanical contact with pneumatic pressure resolution eliminates wear on both the seal and the drying wire while maintaining effective paper detachment.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If opposing air flows are used to create low-pressure areas, then detachment is improved, but turbulent air flows cause instability

Engineering Contradiction:

Improvepaper detachmentVSAvoidair flow stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent inverts the approach by blowing air against the direction of travel of the drying wire, rather than using opposing flows that create turbulence. The nozzle directs air flow opposite to the wire movement, creating a controlled low-pressure area without turbulent interference. This inverted flow direction stabilizes the air flow while maintaining effective paper detachment.

Inventive Principle:

Principle #13The other way round (Inversion)

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 solution effectively enhances paper detachment from the drying cylinder while minimizing wire damage and maintaining wire tension, achieving improved paper transfer efficiency and reducing the risk of wire bending and mechanical seal wear.

Implementation Method 1

the speed of the secondary air increases, and the static pressure decreases according to the aforementioned Bernoulli's Law

Methodology Applied

Scientific EffectBernoulli's Law: Bernoulli Effect

Data Source

PatentEP2331749B1Apparatus and method for improving the detachment of paper from a drying cylinder of a paper machine

Publication Date: 2018.10.17 EV GRP

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AI summary

The object of the invention is an apparatus and a method for improving the detachment of paper (1) from the cylinder of a paper machine in a drying section implemented with a single wire transfer, which drying section comprises means for heating the paper on the drying cylinder (3) and for transporting it onwards on the wire (2) via a hitch roll (8) to the next drying cylinder such that the paper together with the wire in the section between the cylinders is sucked against the wire by means of low pressure. What is essential to the invention is that in order to improve the detachment of the paper (1) an apparatus is installed on the opposite side of the drying wire (2) at the detachment point (7), which apparatus comprises a nozzie (14), with which an air jet (11) is blown against the direction of travel (15) of the drying wire, and a carrying surface (9) such that the air jet (11) ejects secondary air (17) along with it causing an air flow (18) between the planar carrying surface (9) and the drying wire (2).