Screw Conveyor Sludge Dewatering with Screen Filtration

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Solution Overview

Problem

Existing dewatering apparatuses, such as centrifugation, flotation concentration, and screen concentration methods, incur high costs due to equipment expenses, power consumption, and the need for large areas and cleaning water, necessitating a cost-effective solution for efficiently separating liquids from sludge.

Innovation Solution

A screw conveyor type separation apparatus with a cylindrical casing and screw blades, featuring a gap for liquid passage and a drainage port, which allows efficient separation and recirculation of liquids, reducing equipment costs and maintenance needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If centrifugation method is used, then separation efficiency is improved, but power consumption increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the centrifugal separation mechanism with a screw conveyor-based mechanical separation system. The screw conveyor uses rotational motion to convey sludge while liquid passes through the screen, eliminating the need for high-speed rotation and centrifugal force, thereby reducing power consumption while maintaining separation efficiency.

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

Solution Approach 2:

The patent changes the separation mechanism from centrifugal force-based to gravity and mechanical conveyance-based. By altering the separation parameter from high-speed rotation to low-speed screw conveyance with screen filtration, the system achieves comparable separation efficiency with significantly reduced energy consumption.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If flotation concentration method is used, then separation efficiency is improved, but site area increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidsite area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent combines the separation and concentration functions into a single integrated screw conveyor unit with screen filtration. This merging of functions eliminates the need for separate flotation tanks and associated equipment, achieving high separation efficiency while minimizing the required site area.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The screw conveyor system performs multiple functions simultaneously: separation of liquid from sludge, concentration of sludge, and conveyance of treated material. This multi-functionality reduces the overall system footprint while maintaining effective separation performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If screen concentration and dewatering method is used, then separation efficiency is improved, but cleaning water consumption increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidcleaning water
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The screen in the screw conveyor system is designed to be self-cleaning through the mechanical action of the rotating screw and the flow of material. The continuous movement prevents clogging and reduces the need for external cleaning water, while still achieving effective separation of liquid from sludge.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the cleaning function from the separation process by designing a screen system that relies on mechanical self-cleaning rather than water-based cleaning. This extraction of the cleaning requirement eliminates the need for large quantities of cleaning water while maintaining separation efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

4Productivity

If conventional dewatering apparatus is used, then separation efficiency is improved, but equipment cost increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidequipment cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The patent employs a simple screen structure instead of complex filtration systems. The screen can be easily manufactured and replaced if needed, providing cost-effective separation functionality without requiring expensive equipment while maintaining effective liquid-solids separation.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The separation system is divided into simple functional components: the screen for filtration and the screw conveyor for mechanical separation and conveyance. This segmentation into basic, easily manufactured parts reduces overall equipment cost while achieving effective separation efficiency.

Inventive Principle:
Principle #1Segmentation

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 efficiently separates liquids from sludge while minimizing maintenance and operational costs, as it allows for effective liquid recirculation and reduced energy consumption, eliminating the need for extensive cleaning and costly equipment.

Implementation Method 1

a cylindrical inner peripheral side surface of the casing and the first screw blade and second screw blade may have a gap therebetween, the gap allowing the liquid component to pass therethrough, and not allowing the treatment object to pass therethrough

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3153312B1Screw-conveyor-type separating device and waste water treatment system
Publication Date: 2019.07.31 METAWATER CO LTD
  • EP3153312B1 patent drawingFigure 1
  • EP3153312B1 patent drawingFigure 2~3
  • EP3153312B1 patent drawingFigure 4~5

AI summary

A casing 11 that squeezes sludge floc at one end portion, a screw shaft 12, a first screw blade 13 spirally provided on an outer peripheral surface of the screw shaft 12, and a second screw blade 14 provided side by side along a longitudinal direction of the screw shaft 12 with the first screw blade 13 with a predetermined interval from the first screw blade 13, are included. In the casing 11, a concentration zone Q and a separated liquid zone R, which are substantially divided from each other by the first screw blade 13 and the second screw blade 14, are formed. By rotation of the screw shaft 12, the sludge floc is squeezed in the concentration zone Q to be separated into sludge 18 and separated liquid 17, and the separated liquid 17 is moved rearward in the separated liquid zone R to be discharged, while the sludge 18 is discharged outside.