Mechanical Backflow Valve with Buoyancy Actuation

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Solution Overview

Problem

Existing backflow prevention systems in sewage systems are unreliable during power failures and can lead to wastewater backup, preventing drainage and causing damage or contamination.

Innovation Solution

A device with a floating body and slide valve system that operates independently of electricity, using a drain pump and check valves to manage backflow, and includes a storage tank for maintenance readiness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrical blocking elements and sensors are used in the sewer pipe, then backflow prevention is achieved, but the system becomes unreliable during power failures

Engineering Contradiction:
Improvebackflow prevention reliabilityVSAvoidelectrical power dependency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces electrical blocking elements with a mechanical slide valve that is actuated by a floating body responding to water level changes. This mechanical system operates independently of electrical power, ensuring reliability during power failures while maintaining backflow prevention functionality.

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

Solution Approach 2:

The floating body automatically responds to rising water levels in the pumping shaft and actuates the slide valve without requiring external power or control systems. The system uses the natural buoyancy force and water level changes to trigger the backflow prevention mechanism, making it self-regulating and power-independent.

Inventive Principle:
Principle #25Self-service

2Reliability

If backflow valves are installed to prevent backflow, then water backflow is blocked, but wastewater drainage is also prevented when the sewer pipe is blocked

Engineering Contradiction:
Improvebackflow protectionVSAvoidwastewater drainage capability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system separates the backflow prevention function (slide valve in the sewer pipe) from the drainage function (pumping shaft and drain pump). This segmentation allows the backflow prevention mechanism to operate independently without blocking the alternative drainage path through the pumping shaft, enabling wastewater to be pumped out even when the sewer pipe is blocked.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pumping shaft acts as an intermediary structure that provides an alternative drainage path. When the sewer pipe is blocked, wastewater flows into the pumping shaft through the overflow element and is then pumped out via the drain pump, maintaining drainage capability while the slide valve prevents backflow into the building's wastewater pipe.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If a slide valve is pushed into the wastewater pipe to prevent backflow, then backflow is blocked, but solids in the pipe may obstruct the valve operation

Engineering Contradiction:
Improvebackflow preventionVSAvoidslide valve operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The floating body is positioned in the pumping shaft and connected to the slide valve such that it automatically acts when water level rises, pushing the slide valve into the sewer pipe before backflow can occur. This preliminary action ensures the valve is positioned correctly to prevent backflow while minimizing the risk of solids obstructing its operation.

Inventive Principle:
Principle #10Preliminary 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

Ensures reliable wastewater drainage and prevents backflow, maintaining functionality even during power outages by using mechanical components and regular maintenance mechanisms.

Implementation Method 1

a floating body (7) is arranged in the pumping shaft (14), the position of which can be changed depending on the water level in the pumping shaft

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

The floating body (7) is connected to a slide valve (17), in particular a plate slide valve, in such a way that the slide valve (17) can be pushed into the flow path of the wastewater into the sewer pipe (2)

Methodology Applied
Scientific EffectMechanical blocking: Valve

Implementation Method 3

a drain pump (11) with a pump line (12) connected to the drain pump (11) is arranged in the pumping shaft (14), with which water can be transported from the pumping shaft (14) into the sewer pipe (2) at positive pressure

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

Two check valves (8, 10) are arranged in the pump line (12). These are intended to prevent wastewater from the wastewater pipe (1) or the sewer pipe (2) from being forced through the pump line (12) into the pump shaft (14)

Methodology Applied
Scientific EffectCheck valve mechanism: Valve

Data Source

PatentEP4095330B1Device for avoiding the backflow of water from a sewer pipe into a sewer pipe of a building
Publication Date: 2025.08.20 OFNER HUBERT
  • EP4095330B1 patent drawingFigure 1
  • EP4095330B1 patent drawingFigure 2
  • EP4095330B1 patent drawingFigure 3

AI summary

The invention relates to a device for preventing backflow of water from a sewer pipe into a wastewater pipe (1) of a structure, in particular a building, comprising a wastewater pipe (1) that opens into a sewer pipe (2), wherein the wastewater pipe (1) has an overflow element (4) from which water from the wastewater pipe (1) can flow into a lower pump shaft (14), wherein the overflow element (4) is arranged and designed such that, under normal conditions, wastewater in the wastewater pipe (1) can flow unhindered to the sewer pipe (2) and, in a backflow condition, water entering from the sewer pipe (2) into the wastewater pipe (1) flows into the pump shaft (14) via the overflow element (4), wherein a float (7) is arranged in the pump shaft (14), the position of which can be changed depending on the water level in the pump shaft (14), wherein the float (7) is connected to a gate valve (17), in particular a plate gate valve, such that is connected in a force-transmitting manner,that the valve (17) can be inserted into the flow path of the wastewater into the sewer pipe (1) when the water level in the pump shaft (14) rises above a predefined threshold value, and the flow of water into or out of the sewer pipe (2) can be interrupted.