Vertical Backflow Seal With Self-Cleaning Drop Flap

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Solution Overview

Problem

Common backflow preventers face issues with contamination from particularly dirty wastewater, such as faeces, leading to impaired functionality due to dirt particles adhering to movable parts and seals.

Innovation Solution

A tubular backflow preventer with a pivotable drop flap that automatically closes against gravity in the normal position, opening in the direction of gravity to allow wastewater flow, utilizing wastewater kinetic energy for cleaning and reducing contamination, and featuring a vertical installation orientation to create an air cushion for protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex design measures are taken to improve backflow prevention function, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvebackflow prevention functionVSAvoiddesign measures
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent converts the harmful effect of wastewater flow (which could carry contaminants) into a beneficial cleaning mechanism. The wastewater flow automatically cleans the closing parts and sealing seals by flushing them during normal operation, eliminating the need for complex manual cleaning or maintenance systems while ensuring reliable backflow prevention function.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The backflow preventer performs self-cleaning through its own operational wastewater flow. The system uses its functional operation (wastewater passage) to simultaneously clean its own critical components, eliminating the need for external maintenance systems or complex design measures for component protection.

Inventive Principle:
Principle #25Self-service

2Reliability

If the backflow preventer is designed to handle contaminated wastewater, then reliability is improved, but contamination of functional parts occurs

Engineering Contradiction:
Improveoperational reliabilityVSAvoidcontamination of functional parts
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent transforms the contaminated wastewater from a harmful contaminant source into a beneficial cleaning agent. The wastewater flow continuously flushes the closing parts and sealing seals, preventing contaminant accumulation and maintaining operational reliability without requiring additional protection mechanisms.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The cleaning action occurs periodically with each wastewater flow cycle. Every time wastewater passes through the preventer, it automatically cleans the functional parts, creating a continuous periodic cleaning regimen that prevents contamination buildup while maintaining reliable operation.

Inventive Principle:
Principle #19Periodic action

3Ease of operation

If the drop flap is positioned to allow easy opening by wastewater flow, then ease of operation is improved, but contamination of the drop flap increases

Engineering Contradiction:
Improvedrop flap openingVSAvoidcontamination of drop flap
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent converts the wastewater flow that causes contamination into a cleaning mechanism. The same flow that opens the drop flap also flushes and cleans it, eliminating the net contamination effect while maintaining easy automatic operation of the flap.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The drop flap is self-cleaning through the wastewater flow that operates it. The functional operation of opening and closing the flap simultaneously performs the cleaning function, eliminating the need for separate protection or cleaning mechanisms.

Inventive Principle:
Principle #25Self-service

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 design ensures reliable operation even with contaminated wastewater by minimizing contamination on functional components, efficiently flushing away dirt, and preventing contact between backflow wastewater and critical parts, enhancing operational reliability.

Implementation Method 1

the drop flap allows wastewater to flow in the direction of the wastewater passage path through an open position and blocks it against the direction of the wastewater passage path through a closed position, wherein the drop flap is automatically closed against the direction of gravity in a vertical installation orientation of the backflow preventer in a normal position and opens automatically in the direction of gravity in a wastewater passage situation

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

the wastewater flow hitting the flap valve, which is closed in the normally closed position, in a wastewater passage situation cleans the flap valve and the flap valve opening and noticeably reduces and in some cases even prevents the adhesion of contaminants to these functionally relevant components

Methodology Applied
Scientific EffectFluid flow cleaning: Fluid Spray

Implementation Method 3

the vertical installation orientation allows the kinetic energy of the wastewater to be used to efficiently flush the backflow preventer, which reduces dirt deposits and further increases the operational reliability of the backflow preventer

Methodology Applied
Scientific EffectKinetic energy: Impact Force

Implementation Method 4

the standard closed position of the trapdoor ensures that an air cushion is reliably formed below the closed trapdoor opening in a backflow situation, which makes it possible to position functionally relevant parts of the backflow preventer, such as the trapdoor and the trapdoor opening, in such a way that the level of the backflow wastewater does not come into contact with these functionally relevant parts

Methodology Applied
Scientific EffectAir cushion: Air Lubrication

Data Source

PatentEP4624690A1Vertical backflow seal with automatically closed falling flap
Publication Date: 2025.10.01 KESSEL SE CO KG
  • EP4624690A1 patent drawingFigure 1
  • EP4624690A1 patent drawingFigure 2
  • EP4624690A1 patent drawingFigure 3

AI summary

The present invention relates to a tubular backflow preventer for vertical installation in a sewer pipe gradient, comprising a wastewater inlet nozzle and a wastewater outlet nozzle, wherein a wastewater passage path of the backflow preventer runs from the wastewater inlet nozzle to the wastewater outlet nozzle, a pivotable drop flap which interacts sealingly with a drop flap opening between the wastewater inlet nozzle and the wastewater outlet nozzle, and the drop flap allows wastewater to flow in the direction of the wastewater passage path through an open position and blocks it against the direction of the wastewater passage path through a closed position, wherein the drop flap is automatically closed against the direction of gravity in a vertical installation orientation of the backflow preventer in a normal position and opens automatically in the direction of gravity in a wastewater passage situation.The invention also relates to an associated wastewater lifting system.