Downpipe Backflow Seal for Reliable Wastewater Lifting Systems

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Solution Overview

Problem

Wastewater lifting systems, particularly those handling blackwater, are maintenance-intensive and prone to operational failures due to incorrect or insufficient maintenance, which can lead to unreliable operation.

Innovation Solution

Incorporating a backflow preventer in the downpipe section of the wastewater conveying line that automatically closes during backflow events, with features like a widened passage area and strategic positioning to minimize contamination and enhance flushing, ensuring reliable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a backflow preventer is installed in the lifting station, then backflow protection is improved, but the risk of contamination and maintenance complexity increases

Engineering Contradiction:
Improvebackflow protectionVSAvoidcontamination risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The backflow preventer is extracted from the lifting station and repositioned in the downpipe section. This separates the backflow protection function from the lifting station environment, removing it from the contaminated wastewater zone while maintaining its protective function. The device is taken out of the problematic environment (lifting station with faecal wastewater) and placed in a cleaner location (downpipe section).

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The downpipe section acts as an intermediary location between the lifting station and the sewer system. By placing the backflow preventer in this intermediate zone, the system benefits from the velocity of flowing wastewater that prevents contamination adhesion, while the backflow preventer still protects against backflow events. The downpipe section serves as a mediating environment that reduces contamination risk to the device.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If maintenance is performed at correct intervals, then system reliability is improved, but maintenance requirements still create operational interruptions

Engineering Contradiction:
Improvesystem reliabilityVSAvoidmaintenance downtime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The backflow preventer in the downpipe section benefits from self-cleaning through the velocity of flowing wastewater, which prevents contamination from adhering to functional components. This self-maintaining characteristic reduces the frequency and complexity of manual maintenance interventions, allowing the system to maintain itself through normal operation rather than requiring scheduled maintenance shutdowns.

Inventive Principle:
Principle #25Self-service

3Reliability

If the backflow valve closes quickly during backflow events, then backflow protection is improved, but the force of closing can damage lifting station components

Engineering Contradiction:
Improvebackflow prevention effectivenessVSAvoidcomponent durability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The downpipe section provides a cushioning effect by positioning the backflow preventer where the wastewater column has already begun to decelerate due to gravity. This reduces the kinetic energy of the backflowing wastewater before it reaches the valve, cushioning the impact and reducing the force with which the valve must close. The system prepares for the backflow event by allowing the wastewater to naturally decelerate in the downpipe section before reaching the preventer.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 backflow preventer significantly enhances system reliability by preventing rapid backflow, reducing contamination, and maintaining the integrity of components, allowing the system to handle problematic wastewater effectively.

Implementation Method 1

a backflow valve which allows wastewater to pass through in the wastewater conveying direction and closes in the event of a wastewater backflow event

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

a downpipe section in which wastewater moves in the direction of gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 3

a wastewater lifting plant with a wastewater conveying line, wherein the wastewater lifting plant is designed to pump wastewater through the wastewater conveying line in the wastewater conveying direction from a geodetically lower level to a geodetically higher drainage level

Methodology Applied
Scientific EffectPumping: Pump

Data Source

PatentEP4624685A1Waste water lifting system with backflow seal in the downpipe
Publication Date: 2025.10.01 KESSEL SE CO KG
  • EP4624685A1 patent drawingFigure 1
  • EP4624685A1 patent drawingFigure 2
  • EP4624685A1 patent drawingFigure 3

AI summary

The present invention relates to a wastewater lifting system, comprising a wastewater lifting plant with a wastewater conveying line, wherein the wastewater lifting plant is designed to pump wastewater through the wastewater conveying line in the wastewater conveying direction from a geodetically lower level to a geodetically higher drainage level, wherein the wastewater conveying line has a riser section in the wastewater conveying direction, a curved line section with a peak level of the wastewater conveying line, and a downpipe section in which wastewater moves in the direction of gravity, the wastewater lifting system further comprising a backflow preventer which allows wastewater to pass through in the wastewater conveying direction and closes in the event of a wastewater backflow event, characterized in that the downpipe section has the backflow preventer.The invention also relates to an associated method for installing or improving a sewage lifting system and an associated use of a sewage backflow preventer for improving system reliability.