Cyclone Separator for Tissue Exhaust Heat Recovery

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The contamination of heat recovery stages by paper fibers in the exhaust air of tissue paper production systems leads to reduced heat recovery performance and increased maintenance efforts, often requiring frequent cleaning or even system shutdowns due to clogged filter systems.

Innovation Solution

Implementing a cyclone separator to clean the process exhaust air of entrained particles, such as paper fibers, before the heat recovery stages, allowing for reliable separation and extended maintenance cycles, and optionally directing the cleaned particles to a sewer for disposal, thereby minimizing power loss and maintenance needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a classic filter system is used to clean exhaust air, then particle removal is achieved, but the filter clogs quickly requiring frequent maintenance and cleaning

Engineering Contradiction:
Improveparticle contaminationVSAvoidmaintenance frequency
Core Design Contradiction:
Object-affected harmful factorsVSEase of repair

Solution Approach 1:

The patent replaces the mechanical filter system with a cyclone separator that uses centrifugal force generated by rotating airflow to separate particles. This substitution eliminates the clogging problem inherent in filter systems while maintaining effective particle removal from the exhaust air

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The cyclone separator utilizes pneumatic principles by creating a rotating airflow pattern that generates centrifugal force. The air stream itself acts as the separating mechanism, with heavier particles being thrown outward to the walls where they are collected, while cleaned air exits through the central outlet

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Object-affected harmful factors

If filter systems are used in high fiber load applications, then particle separation occurs, but maintenance effort increases significantly

Engineering Contradiction:
Improvefiber contaminationVSAvoidmaintenance time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The cyclone separator is designed to be self-cleaning through the continuous airflow that prevents particle accumulation. The system automatically separates and removes fibers without requiring manual intervention, significantly reducing maintenance time and effort compared to filter systems that must be regularly cleaned or replaced

Inventive Principle:
Principle #25Self-service

3Object-affected harmful factors

If classic filter systems are used, then exhaust air is filtered, but complete blockage may require system shutdown

Engineering Contradiction:
Improveparticle emissionVSAvoidsystem availability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The cyclone separator employs dynamic airflow patterns that continuously adapt to particle loads. The rotating air stream maintains its separating effectiveness even under varying conditions, preventing the complete blockage that occurs in static filter systems and ensuring continuous system operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The cyclone separator performs preliminary particle removal before the air enters subsequent heat recovery stages. This pre-cleaning action prevents particles from reaching and blocking downstream components, maintaining system reliability and availability

Inventive Principle:
Principle #10Preliminary action

4Loss of energy

If heat recovery stages are operated without adequate particle separation, then heat recovery continues, but heat recovery performance decreases due to contamination

Engineering Contradiction:
Improveheat recovery efficiencyVSAvoidparticle deposition
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The cyclone separator is positioned upstream of the heat recovery stages to perform preliminary particle removal. This ensures that particles are separated before the air enters the heat exchangers, preventing deposition on heat transfer surfaces and maintaining high heat recovery efficiency throughout operation

Inventive Principle:
Principle #10Preliminary action

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 maintains high heat recovery efficiency, reduces maintenance requirements, prevents particle contamination in the atmosphere, and minimizes the risk of filter clogging, enabling almost maintenance-free operation and safe disposal of hot particles.

Implementation Method 1

the process exhaust air is at least partially cleaned of entrained particles, in particular paper fibers, by means of at least one cyclone separator

Methodology Applied
Scientific EffectCyclone separation: Cyclone Separation

Implementation Method 2

the particles, in particular paper fibers, to be reliably separated from the air flow before the first heat recovery stage

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Implementation Method 3

at least one first heat recovery stage 2, is preferably fed to several heat recovery stages

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3165674B1Device and method for heat recovery
Publication Date: 2018.07.04 VOITH PATENT GMBH
  • EP3165674B1 patent drawingFigure 1
  • EP3165674B1 patent drawingFigure 2

AI summary

A method for heat recovery from hot process exhaust air of a plant for the production of a fibrous web, in particular a tissue web, characterized in that the process exhaust air is at least partially cleaned of entrained particles, in particular paper fibers, by means of at least one cyclone separator, and is then fed to at least one first heat recovery stage, preferably several heat recovery stages. Furthermore, devices for carrying out the method are proposed.