Backwashable Water Filter with Movable Germicidal Suction Devices

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Solution Overview

Problem

Existing water filtration systems face challenges in effectively addressing germ contamination on non-coated surfaces and in dead spaces, requiring costly silver plating of entire surfaces and limited effectiveness in preventing microbial growth between backwashing intervals.

Innovation Solution

A backwashable water filter with a screen filter insert and movable suction devices coated with a germicidal substance, allowing the coating to cover the filter cake and surrounding areas during backwashing, reducing the need for extensive silver coating and enhancing hygiene.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the entire surface of the screen filter is silver-coated to ensure hygienic operation, then germicidal protection is improved, but manufacturing cost increases significantly

Engineering Contradiction:
Improvegermicidal protectionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The suction devices are selectively silver-coated rather than the entire screen filter surface. This localized application of the germicidal coating concentrates the protective effect where it is most needed (in the suction devices that contact filter cake and stagnant water) while significantly reducing material costs compared to full-surface coating.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The suction devices are made movable relative to the screen filter insert through a drive mechanism. This dynamic design allows the limited silver-coated surfaces to sweep across and contact different areas of the filter cake and filter housing interior during operation, extending the germicidal protection coverage without requiring the entire screen filter surface to be coated.

Inventive Principle:
Principle #15Dynamics

2Reliability

If silver coating is applied to all surfaces including suction devices and filter housing, then hygienic operation is improved, but device complexity and cost increase

Engineering Contradiction:
Improvehygienic operationVSAvoidcoating coverage requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of uniformly coating all surfaces, the invention selectively applies silver coating only to the suction devices. These movable components serve as mobile sources of germicidal protection that contact multiple surfaces (filter cake, filter housing interior, rinsing water channels) during their movement, eliminating the need to coat all these additional surfaces.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The silver-coated suction devices act as intermediary elements that transfer germicidal protection to multiple surfaces indirectly. Rather than requiring direct contact between silver coating and all protected surfaces, the movable suction devices with germicidal coating serve as mobile mediators that bring the protective effect to filter cake, housing walls, and water channels during their operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If backwashing is performed every 2 months to clean the filter insert, then filtration performance is maintained, but microorganism growth occurs on the filter between flushing intervals

Engineering Contradiction:
Improvefiltration performanceVSAvoidmicroorganism growth
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The silver-coated suction devices provide continuous germicidal protection during normal filtration operation, before backwashing is required. This preliminary and ongoing antimicrobial action prevents microorganism colonization on the filter cake and in stagnant water areas throughout the filtration cycle, not just during the periodic backwashing intervals.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The movable suction devices with silver coating continuously contact and disinfect the filter cake and surrounding areas during normal operation. This continuous germicidal action replaces the discontinuous protection that would only occur during periodic backwashing, maintaining hygienic conditions throughout the entire filtration cycle between flushings.

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

This solution provides effective germicidal coverage without the high cost of full surface silvering, ensuring improved hygiene and cost-effectiveness by using a movable germicidal coating on suction devices to combat microorganisms during backwashing.

Implementation Method 1

The oligodynamic, i.e. germicidal effect of traces of silver on microorganisms has been known for a long time

Methodology Applied
Scientific EffectOligodynamic effect:

Data Source

PatentEP1872841B1Reverse-flush water filter
Publication Date: 2009.03.11 JUDO WASSERAUFBEREITUNG
  • EP1872841B1 patent drawingFigure 1

AI summary

A water supply to a dwelling has a transparent water filter (1) assembly with a sieve insert (3) between a water inlet and outlet, and sub-dividing the inner chamber into an inlet chamber (4) and an outlet chamber (5). The water filter (1) inner surface is coated with a bactericide and is movable with respect to the sieve (3). The inlet chamber (4) has one or more suction zones (9) also incorporating a bactericide. The bactericide incorporates metal e.g. silver or silver alloy with an oligo-dynamic action. The suction zone (9) wall is silver-coated plastic. The sieve is coaxial with the housing. The housing inner face is cleaned by the action of a wiper blade (10). The filter cake is removed by back-flush.