Rotating Paddle Screen for Organic Waste Floatable Removal

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Solution Overview

Problem

Conventional waste processing technologies are limited in effectively removing contaminants, particularly floatables, from organic waste fractions, which can disrupt anaerobic digestion processes and result in substandard digestate quality.

Innovation Solution

A device featuring a cylindrical screen with rotating paddles and a blower system that separates contaminants from pre-processed organic waste by breaking it into globs and dispersing them through perforations, using centrifugal force and airflow to carry floatables to a discharge chute, thereby enhancing the quality of organic waste for biological treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional waste processing technology is used, then the processing system is simple, but the removal efficiency of floatables is insufficient

Engineering Contradiction:

Improvecontaminant removal efficiencyVSAvoidprocessing system complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The processing system is segmented into distinct functional zones: a pre-processing zone for initial contaminant removal, a digestion zone for biological treatment, and a post-processing zone for final contaminant removal. This segmentation allows each zone to be optimized for its specific function, achieving high overall contaminant removal efficiency while maintaining reasonable system complexity through modular design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A pre-processing step is implemented before anaerobic digestion to remove large floatables and contaminants from the organic waste stream. This preliminary action reduces the contaminant load entering the digester, improving digestion efficiency and reducing the burden on subsequent processing stages

Inventive Principle:

Principle #10Preliminary action

2Reliability

If floatables are not removed from organic waste, then the processing process is simpler, but the digestate quality deteriorates

Engineering Contradiction:

Improvedigestate qualityVSAvoidcontaminant separation system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system replaces complex mechanical filtration systems with a biological treatment approach using anaerobic digestion. The digester uses microorganisms to break down organic matter and naturally separate contaminants, achieving high digestate quality through biological processes rather than complex mechanical separation equipment

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system changes the physical-chemical parameters of the waste stream through controlled anaerobic digestion conditions (temperature, pH, retention time). These parameter changes facilitate the biological breakdown of organic matter and the separation of contaminants, improving digestate quality without requiring complex separation machinery

Inventive Principle:

Principle #35Parameter changes

3Productivity

If a sidestream loop is added to continuously remove contaminants, then the digester can operate continuously, but the device complexity increases

Engineering Contradiction:

Improvecontinuous operation capabilityVSAvoidcontaminant removal system

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The anaerobic digestion process operates continuously with organic waste fed into the digester and digestate discharged at regular intervals. This continuous operation maximizes productivity and biogas production while maintaining relatively simple equipment compared to systems requiring continuous contaminant removal loops

Inventive Principle:

Principle #20Continuity of useful 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

The solution achieves over 90% removal of floatables, ensuring that the treated organic waste meets stringent standards for co-digestion with WWTP sludge, producing digestate that meets physical contaminant requirements for land application without additional processing steps.

Implementation Method 1

a blower system that separates contaminants from pre-processed organic waste

Methodology Applied

Scientific EffectAirflow:

Implementation Method 2

using centrifugal force and airflow to carry floatables to a discharge chute

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 3

breaking it into globs and dispersing them through perforations

Methodology Applied

Scientific EffectMechanical force: Mechanical Force

Data Source

PatentUS11033940B2Method and device for processing solid waste

Publication Date: 2021.06.15 ANAERGIA BV

AI summary

Organic waste is polished to remove floatable contaminants prior to being biologically treated. In one application, pressed organic waste is polished before being sent to a wet anaerobic digester, optionally to be co-digested with wastewater treatment plant sludge. The organic waste is polished by flinging globs of the organic waste against a screen (3,4) while flowing air across the flinging globs. The polishing can be performed in a device having a rotor (6) with discrete paddles (9,10) inside of a cylindrical screen (2,3,4).