Waste Pelletizing via Air Classification and Waste Heat Drying

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Solution Overview

Problem

Current waste management methods are inefficient and costly due to high labor, energy, and time expenditures, particularly in processing light fractions of waste, which include paper and packaging materials, and lack comprehensive energy recovery and utilization.

Innovation Solution

A method that involves drying waste using waste heat from a turbine, followed by ash and dust removal to maintain the calorific value of pellets, and integrating sewage sludge and PET granules to stabilize energy generation, while using a conveyor belt system with sensors and discriminators for sorting and a pellet press for energy production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional waste processing methods are used to handle light fractions (paper and packaging materials), then the waste can be processed, but high labor, energy, and time expenditures are required, leading to high operating costs

Engineering Contradiction:
Improvewaste processing efficiencyVSAvoidenergy expenditure
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent converts the harmful effect of ash and dust accumulation (which reduces calorific value) into a beneficial separation process. By using air classification and suction technology, the system selectively removes ash and dust particles from the waste stream, transforming what would be a detrimental contaminant into a separable component. This allows the remaining fuel material to maintain high calorific value while the ash is efficiently removed and disposed of or utilized separately.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent replaces conventional mechanical sorting and processing methods with pneumatic and aerodynamic systems. Air classification uses airflow to separate particles based on density and size, while suction technology employs controlled air streams to remove ash and dust. This substitution eliminates the need for labor-intensive manual sorting and reduces mechanical processing requirements, thereby lowering energy consumption and operating costs while improving processing efficiency.

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

2Loss of energy

If waste is incinerated without energy recovery, then waste disposal is achieved, but energy potential is lost and operating costs increase

Engineering Contradiction:
Improveenergy recoveryVSAvoidprocess complexity
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent performs preliminary separation of ash and dust from the waste stream before incineration through air classification and suction technology. By removing these low-calorific-value components in advance, the remaining fuel material has significantly higher calorific value, which maximizes energy recovery potential during subsequent incineration. This preliminary action ensures that the energy released during combustion is optimized, thereby improving overall energy recovery efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the separated ash and dust are continuously monitored and adjusted in the separation process. By measuring the calorific value and composition of the fuel material, the system can optimize the separation parameters to maintain maximum energy content in the incinerable fraction. This feedback loop ensures consistent energy recovery efficiency while adapting to variations in waste composition, thereby managing process complexity through intelligent control.

Inventive Principle:
Principle #23Feedback

3Device complexity

If ash and dust are not removed from dried waste, then the drying process is simpler, but the calorific value of pellets is reduced, affecting energy production stability

Engineering Contradiction:
Improvedrying process complexityVSAvoidcalorific value stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces air as an intermediary medium to separate ash and dust from dried waste. The air classification system uses controlled airflow to carry away lightweight ash and dust particles while leaving behind the heavier, high-calorific-value fuel material. This intermediary approach efficiently removes contaminants without requiring complex mechanical separation equipment, thereby maintaining calorific value stability while keeping the process relatively simple.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs pneumatic technology through suction systems and air streams to remove ash and dust from the dried waste. By using pressurized air flows and suction forces, the system selectively extracts lightweight particulate matter that would otherwise contaminate the fuel pellets. This pneumatic approach provides a reliable and stable method for maintaining calorific value without introducing excessive mechanical complexity into the drying and separation process.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 reduces operating costs, ensures stable energy production by maintaining the calorific value of pellets, and optimizes waste processing by integrating energy recovery and sorting techniques, enhancing the overall efficiency of waste management.

Implementation Method 1

the energy required for the drying process being supplied by the waste heat of a turbine, which itself is used to generate energy

Methodology Applied
Scientific EffectWaste heat: Heat Exchanger

Implementation Method 2

the heavy fraction that occurs is subjected to predominantly granulating secondary comminution. The two shredding products are then brought together again

Methodology Applied
Scientific EffectAir classification: Cyclone Separation

Data Source

PatentEP1874476B1Waste disposal method and device
Publication Date: 2009.07.15 ORAWETZ UTA
  • EP1874476B1 patent drawingFigure 1
  • EP1874476B1 patent drawingFigure 2

AI summary

Disclosed are a waste disposal method and device having the following characteristics: a) a water basin (2, 2a, 2b, 2c) for separating metal components; b) a water basin (3) for separating plastic components and minerals; c) mills (3b, 3d) for processing the plastic components into granulate; d) a mill (4) for comminuting the remaining waste; e) a drying stage (5) for drying the remaining waste; f) a stage (6) for removing ashes from the dried waste; g) a mixing stage (7) for mixing the ash-free waste with plastic granulate and sewage sludge at an adjustable ratio; a press (8) for shaping the mixed product into pellets; i) a stage for burning (9) the pellets in order to generate power.