Rich-lean burner partition plate projections for flame stability

Solution Overview

Problem

Existing rich-lean burners for gas combustion apparatuses, like water heaters, face instability and noise issues due to the gap between lean-flame and rich-flame ports, which causes pilot flames to flutter, leading to undesirable vibrations and noises.

Innovation Solution

A rich-lean burner design where projections on partition plates create a recessed portion allowing partial lean gas supply to the gap between the ports without using holes, ensuring fluid communication and stabilizing pilot flames.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a gap of predetermined distance is left between lean-flame port and rich-flame port to restrict interference between flames, then flame stability is improved, but pilot flame becomes unstable causing flutter and noise

Engineering Contradiction:

Improveflame stabilityVSAvoidnoise and vibration

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The partition plate is designed with non-uniform thickness, creating different local qualities in the gap region. The thinner portion allows lean gas to pass through while the thicker portion maintains structural integrity and flame separation, thus stabilizing the pilot flame without causing flutter and noise.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The partition plate acts as an intermediary structure between the lean-flame port and rich-flame port. By incorporating a through-hole in the thinner portion of the partition plate, lean gas can be selectively supplied to the gap region to stabilize the pilot flame while the partition plate itself maintains the necessary separation and prevents harmful interactions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If holes are used in partition plate to supply lean gas into gap, then pilot flame stability is improved, but device complexity increases

Engineering Contradiction:

Improvepilot flame stabilityVSAvoidpartition plate structure

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The partition plate is designed with non-uniform thickness, creating different local qualities in the gap region. The thinner portion allows lean gas to pass through while the thicker portion maintains structural integrity and flame separation, thus stabilizing the pilot flame without causing flutter and noise.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The partition plate acts as an intermediary structure between the lean-flame port and rich-flame port. By incorporating a through-hole in the thinner portion of the partition plate, lean gas can be selectively supplied to the gap region to stabilize the pilot flame while the partition plate itself maintains the necessary separation and prevents harmful interactions.

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

The solution stabilizes pilot flame combustion, reduces noise and vibrations, and allows for efficient lean gas supply to the gap, enhancing combustion stability without the need for holes in partition plates.

Implementation Method 1

The gap is in fluid communication with a supply passage through which the lean gas is to be supplied to the lean-flame port

Methodology Applied

Scientific EffectFluid flow through passage:

Implementation Method 2

a main flame by burning air-fuel mixture (lean gas) of which the air-fuel ratio is lower than a theoretical air-fuel ratio of the gas at a lean-flame port, and to form a pilot flame by burning air-fuel mixture (rich gas)

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS9091436B2Rich-lean burner

Publication Date: 2015.07.28 PALOMA RHEEM HLDG CO LTD

AI summary

In a rich-lean burner, a gap formed between a lean-flame port and a rich-flame port is in fluid communication with a supply passage through which a lean gas is to be supplied to the lean-flame port. One or more projections are provided on at least one of partition plates disposed between the gap and the lean-flame port and between the gap and the rich-flame port. A recessed portion is formed at a region adjacent to the lean-flame ports at an interface between the distal end of at least one of the projections protruding from one of the partition plates and the other of the partition plates, the distal end of the at least one of the projections being partially not in contact with the other of the partition plates to provide a clearance through which the lean gas is allowed to be supplied to the gap.