Tunnel Ventilation High-Pressure Water Atomization Filtration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing systems for filtering exhaust gases and fresh air in tunnels, particularly in railway, road, or motorway tunnels, are ineffective in addressing the harmful effects of fire-related or vehicular traffic emissions, as they do not adequately treat the gases and can cause fluid-dynamic disorders, and require frequent maintenance and high environmental impact.

Innovation Solution

A system utilizing high-pressure atomized water with nozzles producing drops of less than 250 µm diameter, operated at a minimum pressure of 200 bar, to filter exhaust gases and fresh air, incorporating porous laminar elements and multiple filtering units for effective particulate and pollutant removal, with minimal environmental impact and reduced inlet losses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If water is used to wash exhaust gases to decrease temperature, then the temperature of exhaust gases is reduced, but the working pressure and drop diameter are not specified leading to ineffective filtration

Engineering Contradiction:
Improveexhaust gas temperatureVSAvoidfiltration effectiveness
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent specifies precise parameters for water atomization: pressure between 150-300 bar and drop diameter between 100-500 micrometers. These parameter changes transform the washing process from ineffective to highly effective, enabling both temperature reduction and reliable particle filtration of exhaust gases.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses high-pressure water injection systems (150-300 bar) to atomize water into fine droplets that effectively contact and cool exhaust gases. The hydraulic system delivers controlled high-pressure water streams that simultaneously achieve temperature reduction and particle capture through optimized spray patterns.

Inventive Principle:
Principle #29Pneumatics and hydraulics

2Reliability

If conventional filtering systems are used, then exhaust gases are treated, but they cause fluid-dynamic disorders and require frequent maintenance

Engineering Contradiction:
Improveexhaust gas treatmentVSAvoidfluid-dynamic performance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention extracts the filtration function from conventional complex filter systems and replaces it with a high-pressure water injection system. By taking out the traditional filter media and using direct water atomization, the system eliminates fluid-dynamic disorders while maintaining effective particle removal and reducing maintenance requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical filter systems with a hydraulic atomization system. Instead of using physical filter media that cause pressure drops and require maintenance, the invention uses high-pressure water jets (150-300 bar) to capture particles, substituting mechanical filtration with a fluid dynamic approach that maintains airflow performance.

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

3Reliability

If high-pressure water atomization is used with nozzles producing drops of less than 250 µm diameter at 200 bar minimum pressure, then filtration effectiveness is improved, but system complexity increases

Engineering Contradiction:
Improveparticulate and pollutant removalVSAvoidhigh-pressure system requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The high-pressure water system serves multiple functions simultaneously: it cools exhaust gases, captures particulate matter through atomized droplets, and removes malodorous substances. This multi-functionality justifies the system complexity by eliminating the need for separate cooling and filtration systems, integrating multiple functions into a single high-pressure water injection apparatus.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 system effectively abates soot, fine dust, and malodorous substances from exhaust gases, prevents dirt entry into ventilation ducts, and maintains low maintenance requirements, ensuring safe and efficient operation with minimal environmental impact and reduced fluid-dynamic disruptions.

Implementation Method 1

a high pressure pump 22, preferably of the plunger type... operated at a minimum pressure of 200 bar

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

one or more high pressure nozzles 24 susceptible to spray atomized water into drops... the average diameter of the drops of atomized water is lower than 250 µm

Methodology Applied
Scientific EffectAtomization: Aerosol

Implementation Method 3

The system effectively abates soot, fine dust, and malodorous substances from exhaust gases

Methodology Applied
Scientific EffectImpaction: Impact Force

Implementation Method 4

filter the exhaust gases and / or the fresh air through high pressure atomized water

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3160597B1System for filtering the fresh air flowing in a tunnel and/or the exhaust gases flowing out therefrom
Publication Date: 2023.11.08 MICHELETTI ENG & CONSULTING SAGL
  • EP3160597B1 patent drawingFigure 1
  • EP3160597B1 patent drawingFigure 2~3
  • EP3160597B1 patent drawingFigure 4

AI summary

A system for the treatment of exhaust gases flowing in and / or flowing out from a tunnel (T) overlying a roadway (R) through a ventilation duct (TV). The system comprises: filtering means (20) to filter the exhaust gases passing through the ventilation duct (TV); fan means (V) to force the evacuation of exhaust gases from the tunnel (T) towards the outer environment or the inflow of the exhaust gases from the outer environment into the tunnel (T) through the ventilation duct (TV); detecting means (10) of at least one parameter of the exhaust gases; control means (30) to activate the filtering means (20) in response to the detection by the first (10) of the exceeding of a predetermined threshold value of the at least one parameter. The filtering means (20) comprise at least one filtering unit (20', 20", 20'") that includes: at least one water reservoir (21); pumping means which include at least one high pressure pump (22); a plurality of high pressure nozzles (24) to spray atomized water into drops having an average diameter lower than 500 μιη, preferably lower than 250 μιη, and at a minimum working pressure of 150 bar, preferably at a minimum working pressure of 200 bar; a line of fluid connection (25) of said at least one water reservoir (21) with said high pressure nozzles (24) passing through said pumping means (22).