Rail Vehicle Air Distribution Valves for Toilet Odor Isolation

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Solution Overview

Problem

Unpleasant odors from toilet cubicles in railway vehicles spread to other areas during tunnel passages due to air circulation from the air conditioning system, despite shutters blocking outlets.

Innovation Solution

An air distribution network with ducts and valves that can close the supply of conditioned air to toilet cubicles when shutters are in the closed position, preventing air flow back into the network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the air conditioning system continues to blow air into the toilet cubicle when the air outlet is blocked by shutters during tunnel passage, then the air conditioning system maintains its cooling function, but air flows back from the toilet cubicle into the distribution network spreading unpleasant odors to other outlets

Engineering Contradiction:
Improveair conditioning cooling functionVSAvoidspread of unpleasant odors
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The air distribution network is segmented into separate controllable zones with individual valves for each outlet or group of outlets. This allows the system to close off the toilet cubicle air supply independently while maintaining air conditioning to other areas, preventing odor backflow while preserving cooling functionality elsewhere in the vehicle

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts air supply to different zones based on operational conditions. During tunnel passage when shutters are closed, the control system automatically closes valves to toilet cubicle outlets while keeping other outlets open, allowing the air conditioning system to adapt its behavior to prevent odor spread while maintaining cooling where needed

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If shutters are closed to block air outlets during tunnel passage, then pressure wave discomfort is reduced, but air flow back from blocked outlets spreads unpleasant odors throughout the vehicle

Engineering Contradiction:
Improvepressure wave discomfortVSAvoidunpleasant odors
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The system takes preliminary action by closing valves to toilet cubicle air outlets before or when the shutters close during tunnel passage. This preventive measure stops conditioned air from entering the blocked toilet outlets, eliminating the pressure differential that would cause odor backflow, while the shutters remain closed to protect against pressure waves

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

Valves are introduced as intermediary control elements between the air conditioning distribution network and the toilet cubicle outlets. These valves act as mediators that can selectively block air flow to specific outlets while allowing air to continue flowing to other areas, decoupling the odor prevention function from the pressure wave protection function

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Prevents the spread of unpleasant odors from toilet cubicles to other outlets by controlling air supply through ducts and valves, maintaining air quality within the vehicle.

Implementation Method 1

the air distribution duct comprising at least one valve configured to close the supply of conditioned air to the toilet cabin when the shutters are in the closed position

Methodology Applied
Scientific EffectValve: Valve

Data Source

PatentEP4467413B1Rail vehicle with improved air conditioning distribution system
Publication Date: 2026.01.21 SPEEDINNOV
  • EP4467413B1 patent drawingFigure 1
  • EP4467413B1 patent drawingFigure 2

AI summary

The vehicle (10) comprises lower (14) and upper (12) platforms, an air conditioning unit (22), an air distribution network (24), and outside air inlet (26) and outlet (28) openings, and shutters (32, 34) for the openings, movable between an open position and a closed position for the corresponding opening. The distribution network (24) comprises an air distribution duct (36), connected to the air conditioning unit (22), and having a plurality of outlets (43a, 43b, 43c, 43d), at least one of which (43d) opens into a toilet cubicle (16). At least one other (43a) opens onto one of the lower (14) or upper (12) platforms. The air distribution duct (36) includes at least one valve (44a, 44b) configured to close the supply of conditioned air to the toilet cabin (16) when the shutters (32, 34) are in the closed position.