Conical Portable Stove Air Draft for Low-Smoke Biomass Burning
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Solution Overview
Problem
Existing portable outdoor stoves inefficiently combust organic materials, leading to increased smoke exhaust, scattered unburnt fuel, and inadequate ash collection, posing safety and environmental concerns.
Innovation Solution
A portable freestanding stove design featuring an upper and lower inverted truncated sheet metal cones with a circumferential ring, an adjustable ash pan, and strategically positioned air intake ports, which enhances air draft and combustion efficiency, preventing unburnt fuel scatter and optimizing ash collection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional portable stove designs are used, then portability and simplicity are maintained, but combustion efficiency is poor and smoke exhaust is increased
Solution Approach 1:
The combustion chamber is divided into an upper cone and a lower cone with an axial gap between them, creating distinct zones for primary combustion and secondary after-burning. This segmentation allows separate control of air intake and combustion processes, improving combustion efficiency while reducing smoke emissions through staged combustion.
Solution Approach 2:
Air intake ports are strategically positioned at specific locations: at the base of the lower cone for primary air supply and at the upper part of the combustion chamber for secondary air supply. This localized air distribution creates optimal combustion conditions in different zones, enhancing burnout efficiency and reducing harmful emissions.
2Ease of operation
If simple grate and ash pan designs are used, then device complexity is reduced, but ash collection is inadequate and unburnt fuel scatters
Solution Approach 1:
The ash pan is designed with flexible connectors and chains allowing it to be suspended and adjusted to different heights. This dynamic positioning system enables optimal ash collection while accommodating different fuel types and combustion intensities, preventing unburnt fuel scatter without requiring a complex fixed supporting structure.
Solution Approach 2:
Struts with specific thickness ratios (0.01-0.1 of the circumferential ring diameter) are introduced as intermediary elements between the combustion chamber and grate. These struts serve as both structural support and flow guides, directing combustion gases and ash toward the collection area while maintaining structural integrity.
3Adaptability or versatility
If fixed combustion chamber design is used, then manufacturing simplicity is maintained, but adaptability to different fuel materials is reduced
Solution Approach 1:
The conical combustion chamber design with adjustable air intake ports and flexible ash pan positioning creates a universal system that can effectively combust various organic materials including wood pieces, branches, and other biomass. The geometric shape and air flow patterns adapt to different fuel characteristics without requiring design modifications.
Solution Approach 2:
The air intake port dimensions and positions can be adjusted to optimize combustion parameters for different fuel materials. The axial gap between cones and the port configurations allow modification of air supply rates and combustion chamber volume, enabling adaptation to various fuel types while maintaining the same basic structure.
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 design achieves improved fuel combustion efficiency, reduced smoke emission, effective ash collection, and enhanced safety by ensuring complete burnout of organic materials, while being easy to assemble and transport.
Implementation Method 1
Second lower inverted truncated cone made of sheet metal to provide air draft is located below the upper cone
Implementation Method 2
open combustion chamber 1 surrounded by sidewall 2 and grate 3... increased effectiveness of fuel material after-burning
Implementation Method 3
combust organic material pieces, especially wood pieces... increased efficiency of after-burning and decreased smoke exhaust
Implementation Method 4
upper inverted truncated sheet metal cone 6 of combustion chamber 1 and surrounding thereof circumferential vertical sheet metal ring 7. Second cone 8, i.e. lower inverted truncated sheet metal cone for stove air draft
Data Source
AI summary
A portable freestanding stove designed to combust organic material pieces, having open combustion chamber (1) surrounded with sidewall (2) composed of one inverted truncated upper sheet metal cone (6) of combustion chamber (1) and surrounding thereof circumferential sheet metal ring (7) of combustion chamber (1). Positioned under upper cone (6) is second inverted truncated lower sheet metal cone (8) of air draft. Both truncated cones (6, 8) are rigidly positioned, one relative to the other, with axial gap (h) determined by means of circumferential sheet metal ring (7), rigidly connected to them and positioned at external circumference thereof. The lower part of upper cone (6) connects to grate (3), under which sheet metal ash pan (4) is positioned. Circumferential sheet metal ring (7) of stove rests on supporting structure (5).