Fog Generator Valve Switching Propellant Gas Purge

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Solution Overview

Problem

Current fog generators face issues with corrosion due to decomposition of remaining fog generating fluid in the heat exchanger, require greenhouse gas propellants for purging, and often produce malodors, with purging dependent on fluid level and inefficient in removing non-ejected steam.

Innovation Solution

A fog generator design that uses a valve to switch between connecting the fog generating fluid and propellant gas with the heat exchanger, employing a low-toxic, environmentally acceptable propellant gas like nitrogen or noble gases for continuous or pulsed purge flow to remove non-ejected steam independently of fluid level, preventing decomposition and malodor formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pump or propellant gas is used to drive fog generating fluid into the heat exchanger, then fog generation is achieved, but remaining fluid decomposes and causes corrosion when flow stops

Engineering Contradiction:
Improveheat exchanger durabilityVSAvoidcorrosion from decomposed fluid
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary purging action by activating the propellant gas to clear remaining fog generating fluid from the heat exchanger before decomposition can occur. This preliminary removal of harmful substance prevents the subsequent corrosion problem.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The propellant gas creates an inert atmosphere in the heat exchanger that prevents oxidation and decomposition of remaining fluid components. The inert gas displaces oxygen and isolates any residual fluid from reactive conditions that would cause corrosion.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Reliability

If propellant gas is used to purge the heat exchanger, then non-ejected steam is removed, but greenhouse gas restrictions limit propellant choices

Engineering Contradiction:
Improvepurge effectivenessVSAvoidpropellant gas selection
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system changes the parameter of propellant gas selection from traditional greenhouse gases to environmentally acceptable alternatives like nitrogen or noble gases. This parameter change maintains purge effectiveness while complying with environmental restrictions.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the heat exchanger is purged only after fluid level drops low enough, then purging is achieved, but purging cannot occur when fluid level is high

Engineering Contradiction:
Improvepurge availabilityVSAvoidcontinuous protection
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system uses its own propellant gas supply to perform the purging function independently of external fluid level conditions. The propellant gas system serves the dual purpose of both fog generation and heat exchanger purging, providing continuous protection regardless of fluid level.

Inventive Principle:
Principle #25Self-service

4Productivity

If fog generating fluid is continuously driven into the heat exchanger, then fog output is maintained, but decomposition and malodor occur when flow stops

Engineering Contradiction:
Improvefog outputVSAvoidmalodor from decomposition
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The system rapidly skips through the transition from fog generation to purging mode by quickly activating the propellant gas flow. This rapid transition rushes through the vulnerable period where remaining fluid might decompose and generate malodors.

Inventive Principle:
Principle #21Skipping (Rushing through)

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 corrosion and malodor generation by purging non-ejected steam before decomposition occurs, eliminates the need for greenhouse gases, and allows for independent heat exchanger purging regardless of fluid level, resulting in a safer, more environmentally friendly, and cost-effective fog generation system.

Implementation Method 1

a heat exchanger which transforms the fog generating fluid into steam

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

a propellant gas for driving the fluid from the vessel into a heat exchanger

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 3

said connection comprising a valve for controlling the propellant gas purge flow

Methodology Applied
Scientific EffectValve control: Valve

Data Source

PatentEP2207005B1A fog generator
Publication Date: 2012.01.25 BANDIT NV
  • EP2207005B1 patent drawingFigure 1

AI summary

The present invention is directed to a fog generator comprising a vessel that contains a fog generating fluid and a propellant gas for driving the fluid from the vessel into a heat exchanger which transforms the fog generating fluid into steam and is connected with the vessel, a means for ejecting the steam in the form of a fog and connected to the heat exchanger, and a means for purging non-ejected steam out of the heat exchanger into the ambient, wherein the means for purging comprise a connection from the propellant gas volume of the vessel to the heat exchanger for purging the heat exchanger with propellant gas, said connection comprising a valve for controlling the propellant gas purge flow, characterized in that the valve is suitable for switching between connecting the fog generating fluid volume of the vessel with the heat exchanger and connecting the propellant gas volume of the vessel with the heat exchanger.