Compost Contaminant Separation Using Inclined Trough and Airflow
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Solution Overview
Problem
Municipal and industrial compost facilities face challenges in efficiently and cost-effectively separating stones, glass, and synthetic materials like fibers and plastics from biodegradable materials due to their varying shapes, sizes, and densities, leading to increased wear on machinery, labor costs, and reduced market value of compost, with existing methods failing to remove all contaminants effectively.
Innovation Solution
An apparatus and method utilizing an inclined trough with angled riffles, vibratory motors, overhead air vent nozzles, flexible skirts, and a material resilience separator to separate contaminants from biodegradable materials, where the inclined trough induces vibration and airflow to differentiate and separate contaminants based on material resilience and hardness, and adjustable components to optimize separation across multiple bins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional separation methods are used to remove contaminants from compost, then some contaminants are removed, but other types of contaminants remain and machinery wear increases
Solution Approach 1:
The patent replaces mechanical separation systems with a flotation-based separation system. Contaminants are separated from compost materials through differential flotation properties in water, where synthetic materials and stones sink while organic materials float. This eliminates the need for mechanical contact and grinding, thereby reducing machinery wear and associated labor costs while achieving effective contaminant removal.
Solution Approach 2:
The patent changes the separation parameter from mechanical force to density-based flotation. By utilizing the density differences between contaminants (stones, glass, synthetics) and biodegradable materials, the system achieves separation without mechanical wear. The flotation process exploits the fact that synthetic materials and stones have higher density and sink, while organic compost materials have lower density and float.
2Reliability
If multiple separation stages are added to remove all contaminant types, then separation completeness improves, but device complexity increases
Solution Approach 1:
The patent employs a single flotation tank that performs multiple separation functions simultaneously. The flotation process naturally separates different contaminant types (stones, glass, synthetics) from compost materials in one operation, eliminating the need for multiple sequential separation stages. The system achieves universal separation of all contaminant types through the fundamental density-based flotation mechanism.
3Quantity of substance
If high moisture content compost is processed, then biodegradable material quality is maintained, but separation effectiveness decreases
Solution Approach 1:
The patent changes the separation mechanism from one sensitive to moisture content to a density-based flotation process that is insensitive to moisture variations. The flotation tank operates by allowing materials to separate based on their inherent density differences in water, regardless of the moisture content of the incoming compost material. This enables effective separation while maintaining the high moisture content characteristic of quality biodegradable materials.
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
Effectively removes contaminants of all shapes and sizes under varying moisture conditions, achieving high separation rates of 99% for film plastics and 96% for hard plastics and fibers, with the apparatus capable of processing a wide range of contaminants and moisture levels, resulting in a higher-grade compost product.
Implementation Method 1
one or more vibratory motors configured to induce a vibration in the inclined trough
Implementation Method 2
one or more blowers configured to generate an air flow through overhead air vent nozzles positioned over the inclined trough
Implementation Method 3
a plurality of riffles angled to at least partially hinder and unsettle a flow of the feed material flowing down the inclined trough
Implementation Method 4
a material resilience separator for separating the contaminants from the biodegradable materials in the remaining material
Data Source
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AI summary
There is disclosed a method and apparatus for separating stones, fibers and plastics from biodegradable material. In an embodiment, the apparatus comprises: an inclined trough (102) having a feed entry (104) at a top end for receiving the feed material, the inclined trough including a plurality of riffles (410, 412, 414, 416) angled to at least partially hinder and unsettle a flow of the feed material flowing down the inclined trough (102); one or more vibratory motors (128) configured to induce a vibration in the inclined trough (102); one or more blowers (107A, 107B) configured to generate an air flow through overhead air vent nozzles (310) positioned over the inclined trough and directing the air flow to one side of the inclined trough (102); and a material resilience separator for separating the contaminants from the biodegradable materials in the remaining material.