DAF Pretreatment Apparatus with Filtering Balls

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Solution Overview

Problem

Conventional dissolved air flotation (DAF) systems are limited in processing capacity, require large installation spaces, and are ineffective in removing suspension solids, necessitating additional pretreatment processes and increased operational costs, especially when dealing with high algae loads.

Innovation Solution

A DAF-type pretreatment apparatus with a filtering compartment containing filtering balls made of fibrous or spongy materials, which are designed to occupy minimal space, effectively remove floating and suspended solids, and facilitate efficient back-washing through a structured back-washing system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional DAF systems are used to remove floating matter, then floating materials can be removed, but processing capacity is limited and suspension solids cannot be effectively removed

Engineering Contradiction:
Improveprocessing capacityVSAvoidremoval effectiveness of suspension solids
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent combines the flotation process and sand filtration process into a single integrated apparatus. The flotation tank includes both a flotation compartment for removing floating matter and a sand filtration compartment for removing suspension solids, allowing both functions to operate simultaneously in one system rather than requiring separate processes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated apparatus performs multiple functions within a single system: it removes floating matter through the flotation process, removes suspension solids through sand filtration, and can handle high algae loads. This multi-functional design eliminates the need for separate precipitation or fiber filter systems.

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

2Reliability

If additional pretreatment processes are added to remove suspension solids, then removal effectiveness improves, but construction cost and operating expenses increase

Engineering Contradiction:
Improveremoval effectiveness of suspension solidsVSAvoidnumber of pretreatment processes
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the flotation process and sand filtration process into a single integrated apparatus. The flotation tank includes both a flotation compartment for removing floating matter and a sand filtration compartment for removing suspension solids, allowing both functions to operate simultaneously in one system rather than requiring separate processes.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If sand filtration process is used to extend DAF capability, then suspension solids removal is achieved, but operation performance is limited by the sand filtration process

Engineering Contradiction:
Improvesuspension solids removal capabilityVSAvoidoperation performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines the flotation process and sand filtration process into a single integrated apparatus. The flotation tank includes both a flotation compartment for removing floating matter and a sand filtration compartment for removing suspension solids, allowing both functions to operate simultaneously in one system rather than requiring separate processes.

Inventive Principle:
Principle #5Merging (Combining)

4Area of stationary object

If gravitation-type fiber filter is used instead of sand filtration, then site area is reduced, but fibers break and entangle requiring frequent replacement

Engineering Contradiction:
Improvesite areaVSAvoidmaintenance frequency
Core Design Contradiction:
Area of stationary objectVSEase of repair

Solution Approach 1:

The patent uses sand as the filtration medium instead of reusable fiber filters. Sand is inexpensive, durable, and does not break or entangle like fiber filters. While sand filters may require periodic backwashing and eventual replacement, the material itself has no fatigue life issues and can be easily replenished.

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

Solution Approach 2:

The patent employs sand as a porous filtration medium in the sand filtration compartment. The sand provides effective filtration for suspension solids while being mechanically robust and resistant to the breakdown that plagues fiber-based filters.

Inventive Principle:
Principle #31Porous 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

The apparatus achieves efficient removal of foreign objects and turbid matter while minimizing space requirements and operational costs, with a maintenance-friendly design that maintains performance even under high algae conditions.

Implementation Method 1

a plurality of filtering balls 3 confined in the filtering compartment part 2 and including fibrous or spongy material to filter turbid matter or floating or suspended solids remaining in the treatment water introduced to the interior of the filtering compartment part 2

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

a dissolved air flotation (DAF)-type pretreatment apparatus capable of removing foreign objects (or foreign materials) such as floating matter, turbid matter (or turbidity solids), alga (or algae)

Methodology Applied
Scientific EffectDissolved air flotation: Froth Floatation

Data Source

PatentEP2690070B1Dissolved-air flotation-type pretreatment apparatus
Publication Date: 2016.12.14 DOOSAN HEAVY IND & CONSTR CO LTD
  • EP2690070B1 patent drawingFigure 1~2
  • EP2690070B1 patent drawingFigure 3

AI summary

Disclosed is a dissolved air floatation (DAF)-type pretreatment apparatus. The dissolved air floatation (DAF)-type pretreatment apparatus includes: a floatation tank for removing foreign objects of floating matter, turbid matter, or alga contained in raw water of seawater, sewage, or wastewater; a filtering compartment part provided in the floatation tank and having one surface and the other surface which are partially opened to allow treatment water obtained by primarily removing floating matter from raw water to pass therethrough; and a plurality of filtering balls confined in the filtering compartment part and including a fibrous or spongy material to filter turbid matter or floating or suspended solids remaining in the treatment water introduced to the interior of the filtering compartment part.