Rotating Drum Waste Processing Centrifugal Separation
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Solution Overview
Problem
Current waste processing methods face challenges in recycling materials containing low melting point plastics and metals, as plastics tend to stick together and adhere to processing equipment, preventing effective separation and recovery of both components without labor-intensive manual processes.
Innovation Solution
A method and apparatus utilizing a rotating drum with gaps to centrifugally separate heat-softened plastics from metals, where syngas is produced in an oxygen-free environment and recycled to heat the waste, allowing for efficient separation and recovery of both materials without manual labor, using a system with a heated chamber and treatment chamber connected by conduits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If waste material containing low melting point plastic and metal is heated in a conventional oven, then the plastic melts and can be separated, but the waste sticks together and adheres to the oven walls, preventing effective separation
Solution Approach 1:
The patent applies a rotating drum mechanism that dynamically moves the waste material through the heating zone and into a cooling zone. This dynamic movement prevents the melted plastic from adhering to stationary surfaces while maintaining effective separation through centrifugal force and gravity-assisted discharge.
Solution Approach 2:
The patent uses an oxygen-free or low-oxygen atmosphere during heating to prevent combustion and unwanted chemical reactions of the plastic while it melts. This controlled inert environment allows the plastic to melt and separate without sticking to equipment surfaces through oxidative adhesion.
2Use of energy by moving object
If plastic is pyrolysed to recover energy, then energy is obtained from the plastic component, but the plastic cannot be reused and is lost as a recyclable material
Solution Approach 1:
The patent carefully controls the heating temperature parameter to remain below the pyrolysis threshold of the plastic material. By maintaining temperature within a specific range (melting point to just below decomposition point), the plastic melts for separation and collection without undergoing pyrolysis, thus preserving its recyclability while still enabling separation from metal.
3Loss of substance
If manual separation of plastic from metal is performed to enable recycling, then both materials can be recovered for re-use, but the process requires labor-intensive manual operations that are not financially viable
Solution Approach 1:
The patent replaces manual mechanical separation with an automated thermal-mechanical system. A rotating drum provides both heating (to melt plastic) and centrifugal separation, automatically discharging separated materials without human intervention. This automation makes the process economically viable while achieving complete material recovery.
4Extent of automation
If a rotating drum with gaps is used to centrifugally separate heat-softened plastic from metal, then automated separation is achieved, but the system complexity increases with multiple chambers and conduits
Solution Approach 1:
The rotating drum is designed as a multi-functional component that simultaneously performs heating (through internal heating elements or external heat transfer), rotation-driven centrifugal separation, and material discharge. This consolidation of multiple functions into a single component reduces overall system complexity despite the automated process requirements.
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
Enables the efficient physical separation of plastics and metals, allowing for their recovery and reuse without labor-intensive processes, while maintaining the plastics below their pyrolysis temperature to prevent loss and contamination.
Implementation Method 1
rotating the drum so as to cause the heat softened material to centrifugally separate from the remainder of the waste by passing through the gaps in the drum
Implementation Method 2
passing at least some of said syngas through said waste processing apparatus to heat the material therein to a temperature sufficient to heat soften the heat softening material contained therein
Implementation Method 3
pyrolysing said material containing organic matter within said heated chamber to produce syngas
Implementation Method 4
as the plastic starts to melt and becomes flowable it is physically separated from the metal
Data Source
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AI summary
An apparatus (100) for processing waste material is provided which comprises a heat proof chamber (102), a hot gas inlet (106, 112) for heating the interior of the heat proof chamber (102), and a rotatable drum (118) for containing waste to be processed. The drum (118) has gaps (120) therein, is located within the heat proof chamber (102), and separated therefrom around its edge by a gap. The apparatus (100) is also provided with a drive (126, 128) for rotating the drum (118) at a speed such that, in use, waste material that is heat softened is centrifugally separated from the remainder of the waste and passes through the gaps (120) in the drum (118).