Propylene Glycol Combustion Wick Cooling System

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current combustion systems using ethanol or isopropanol-based fuels pose explosion and burn injury risks due to their flammability and rapid fire spread, and existing wicks can overheat, affecting flame size and safety, especially when used around children and pregnant women.

Innovation Solution

A combustion system utilizing at least 90 wt% propylene glycol based liquid fuel with a sensing unit for fuel replenishment and a drive unit for cooling the wick, ensuring safe operation and flame stability through a dual-tank system with a conduit connecting the tanks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ethanol or isopropanol-based fuels are used, then the combustion system can operate, but explosion and burn injury risks increase due to high flammability

Engineering Contradiction:
ImprovesafetyVSAvoidexplosion and burn injury risks
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameter of the fuel by using propylene glycol-based fuel with at least 60 wt% propylene glycol content, which has a flash point of at least 50°C (up to 104°C depending on compounding ratio). This parameter change transforms the fuel from highly flammable (ethanol/isopropanol) to non-inflammable at room temperature, eliminating explosion and burn injury risks during fuel handling while maintaining combustion capability under controlled conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If metal wicks are used, then carbonization and wear during combustion are eliminated, but the wick gets overheated due to good thermal conductivity

Engineering Contradiction:
Improvecombustion stabilityVSAvoidwick temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent employs a composite wick structure combining metal and non-metallic materials. The metal component provides structural support and resistance to carbonization/wear, while the non-metallic component (such as ceramic fiber, silicate fiber, or rock wool) provides thermal insulation to prevent overheating. This composite approach leverages the advantages of both material types to achieve stable combustion without excessive wick temperature.

Inventive Principle:
Principle #40Composite materials

3Device complexity

If the wick and fuel remain hot after flame extinction, then the system is simple, but toxic chemicals are produced through fuel evaporation

Engineering Contradiction:
Improvesystem complexityVSAvoidtoxic exhaust chemicals
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the hot wick and fuel residue from the combustion chamber after flame extinction by introducing a cooling airflow. This active removal prevents continued evaporation of hot fuel and eliminates the source of toxic chemicals. The system adds a cooling mechanism (such as a fan or forced convection system) to actively manage thermal conditions and prevent harmful emissions, prioritizing health safety over minimal system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides a safe and stable combustion environment by preventing overheating of the wick and minimizing toxic exhaust, leveraging propylene glycol's high flash point to maintain flame size and extinguish safely, suitable for use in environments with children and pregnant women.

Implementation Method 1

The wick may be made of, for example, glass fibers, ceramic fiber materials, silicate fiber materials or rock wool, or polymeric materials such as aramid fibers, cotton or porous materials such as pumice, or other wick materials known in the art. In contrast to wicks made of other materials, the metal wick does not produce carbonization and wear during combustion and so more suitable for burning propylene glycol based liquid fuels completely.

Methodology Applied
Scientific EffectCapillary attraction: Capillary Action

Implementation Method 2

a drive unit connected with the conduit system and configured to receive the fuel replenishment signal so as to cause the propylene glycol based liquid fuel in the second fuel tank to replenish the first fuel tank through the conduit system as well as to cool the wick

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4212772B1Combustion system and method of operation thereof
Publication Date: 2024.01.31 PRO IRODA INDS
  • EP4212772B1 patent drawingFigure 1
  • EP4212772B1 patent drawingFigure 2
  • EP4212772B1 patent drawingFigure 3

AI summary

A combustion system using at least 90 wt% propylene glycol based liquid fuel includes a first fuel tank (10), a wick (11) inserted in the first tank, a sensing unit (12) configured to receive an activating signal and sense the liquid level of the propylene glycol based liquid fuel in the first fuel tank and send a fuel replenishment signal accordingly, a second fuel tank (20), a conduit system (30) connected with the first and the second fuel tanks (10, 20), and a drive unit (40) connected with the conduit system (30) and configured to receive the fuel replenishment signal so as to cause the propylene glycol based liquid fuel in the second fuel tank to replenish the first fuel tank through the conduit system as well as to cool the wick.