Modular Tundish Air Gap and Non-Return Valve for Backflow Prevention

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Solution Overview

Problem

Existing plumbing tundish devices fail to effectively prevent backflow contamination of fresh water systems from discharge, particularly in unvented domestic hot water storage systems, where steam and hot water can cause scalding and contamination risks.

Innovation Solution

A modular tundish device with an elongated grid arrangement and a non-return valve system, featuring a duckbill valve, which creates a large air gap to prevent backflow and allows for visual inspection, while being designed to prevent finger access and secure the valve for safe operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional solid air gap is used in tundish, then backflow prevention is achieved, but visual indication of system faults is limited

Engineering Contradiction:
Improvebackflow preventionVSAvoidvisual indication capability
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent replaces the traditional solid air gap with a grid arrangement consisting of multiple spaced-apart bars, creating a porous structure with numerous small openings. This porous configuration maintains the air break function to prevent backflow while allowing visual observation of discharge through the gaps between bars, thus resolving the contradiction between backflow prevention and visual indication capability

Inventive Principle:
Principle #31Porous materials

2Loss of information

If the air gap structure is made open for visual observation, then fault visualization is improved, but risk of scalding from hot water or steam discharge increases

Engineering Contradiction:
Improvefault visualizationVSAvoidscalding risk
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating a grid structure where the bars are spaced to provide visual observation capability while maintaining sufficient material presence to block direct contact with hot water or steam. The local arrangement of bars and gaps provides different functions in different locations: visual observation through gaps and thermal protection through bar structures

Inventive Principle:
Principle #3Local quality

3Ease of repair

If a modular detachable connector design is used, then ease of maintenance and component replacement is improved, but device complexity increases

Engineering Contradiction:
Improvecomponent replacementVSAvoidconnector structure
Core Design Contradiction:
Ease of repairVSDevice complexity

Solution Approach 1:

The patent divides the tundish device into separate modular components including detachable connectors that can be easily assembled and disassembled. This segmentation allows individual components to be replaced independently for maintenance purposes, resolving the contradiction by making the overall device simpler to maintain despite the added modular connection structures

Inventive Principle:
Principle #1Segmentation

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 solution effectively prevents backflow and odour contamination, provides a visual indicator for system faults, and allows for easy maintenance and versatility in connector sizes and valve types, ensuring safe and efficient discharge of steam and hot water.

Implementation Method 1

The inlet end of a tundish device is connected to the outlet side of the PRV and any discharge from the PRV drips or flows into the tundish. The outlet end of the tundish is arranged to discharge any water to waste. Backflow from waste is prevented by an air gap provided near the top of the tundish

Methodology Applied
Scientific EffectAir gap:

Implementation Method 2

The steam condenses on the end of the PRV and the resulting water drips into a tundish that is connected to the PRV

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 3

a non-return valve, which is operable to prevent backflow of fluid and of odours from the outlet side of the tundish

Methodology Applied
Scientific EffectOne-way valve mechanism: Valve

Data Source

PatentEP3555381B1Plumbing tundish
Publication Date: 2021.06.16 MCALPINE
  • EP3555381B1 patent drawingFigure 1
  • EP3555381B1 patent drawingFigure 2~3b

AI summary

An assembled plumbing tundish device (10) comprises a hollow tubular body (12) formed of at least two mating parts, wherein the hollow tubular body (12) comprises a first hollow connector (14) and a second hollow connector (16), joined together end to end. The first and second hollow connectors (14, 16) are detachably connectable to each other. When connected the first and second hollow connectors (14, 16) form an assembled tundish device (10). The first hollow connector (14) provides an inlet for the assembled tundish device (10) and the second connector provides an outlet for the assembled tundish (10). The first hollow connector (14) includes an air gap (30) proximate the inlet. The air gap (30) comprises a grid arrangement (32) made up of a plurality of windows (35), which are defined in at least two rows by intersecting horizontal and vertical members, wherein the points of intersection of the horizontal and vertical members define corners of the windows.