Rotatable Drum Separator for Waste Incineration Ashes
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Solution Overview
Problem
Existing separation apparatuses struggle to effectively separate particles of small dimensions from particle streams, particularly in cases like bottom ash from waste incineration plants, where particles differ modestly in size and composition, leading to inefficiencies in distinguishing between fractions.
Innovation Solution
A separation apparatus with a rotatable drum and a vibrating infeed-device that creates a controlled monolayer flow, using a housing to protect particles and employing a gas flow to enhance separation, allowing for the classification of particles into fractions based on size, with the infeed-device operating at specific frequencies and amplitudes to direct particles towards the drum for effective separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional separation apparatus is used, then the structure is simple and easy to manufacture, but it cannot effectively separate particles of small dimensions that differ modestly in size
Solution Approach 1:
The separation apparatus is divided into multiple functional zones along the drum circumference: an impact zone where particles strike the drum surface, a separation zone where fractions are differentiated, and a discharge zone where separated fractions are collected. This segmentation allows each zone to perform its specific function optimally, achieving effective separation of fine particles through a structured multi-stage process rather than a single simple mechanism
Solution Approach 2:
The invention transitions from conventional planar separation to three-dimensional spatial separation by utilizing the drum's rotational motion and the vertical distribution of receiving areas at different heights and radial positions. The first receiving area is positioned proximal to the drum while the second receiving area is positioned distant from the drum, creating vertical and radial dimensionality that enables effective separation of particles differing only modestly in size
2Reliability
If particles are processed without a housing, then the apparatus is simpler, but particles of small dimensions cannot be processed under windy conditions
Solution Approach 1:
The housing is designed with differentiated local qualities: it provides enclosed protection in zones where particle flow is sensitive to wind (infeed and separation zones), while maintaining openness or ventilation in zones where it is not critical. The housing structure is strategically positioned to shield the drum and receiving areas from wind interference, ensuring reliable processing of fine particles without completely enclosing the entire apparatus
3Manufacturing precision
If the infeed-device operates without controlled vibration, then the structure is simpler, but particles cannot form a controlled monolayer flow
Solution Approach 1:
The infeed-device incorporates vibratory motion to agitate the particle stream and facilitate the formation of a controlled monolayer flow on the drum surface. The vibration frequency and amplitude are optimized to separate particles by size as they travel along the drum, with finer particles following different trajectories than coarser particles, enabling precise separation without requiring complex mechanical sorting mechanisms
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
The apparatus successfully separates particles into fractions of 0-2 mm and 2-15 mm, enabling efficient classification and water content reduction, facilitating further separation of metals, and is applicable to various particle streams beyond bottom ash.
Implementation Method 1
The infeed-device is a vibrating plate having an edge positioned above the drum, which edge is embodied as an outlet for the particle-stream. The vibrating plate operates in use at a vibrating-frequency of more than 10 Hz and with an amplitude of less than 5 mm
Implementation Method 2
a rotatable drum having at its circumference plates, each plate having a radially extending hitting surface for the particles
Implementation Method 3
a rotatable drum having at its circumference plates... at least a first receiving area proximal to the drum for receipt therein of particles of the first fraction, and at least a second receiving area distant from the drum
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
Method of separating from a particle stream originating from waste-incineration ashes at least a first fraction with particles having small dimensions, and a second fraction with particles having relatively larger dimensions, in which method a separation-apparatus (1) is used to classify metals from said ashes into the first and the second fraction, and wherein the separation-apparatus (1) comprises a rotatable drum (5) having at its circumference (13) plates (6, 6'), each plate having a radially extending hitting surface, at least a first receiving area (11, 11') proximal to the drum (5) for receipt of particles of the first fraction, and at least a second receiving area (12, 12') distant from the drum (5) for receipt of particles of the second fraction, the apparatus further having a housing (6), allowing that the particles (3) of the particle-stream (4) have dimensions in the range 0-15 mm.