Fume Box Catalyst Layout for Low-Temperature Smoke Purification

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Solution Overview

Problem

Existing smoke box systems with oxidation catalysts face inefficiencies in purifying gases and combustion fumes at low temperatures, particularly during fire startup or extinguishing phases, as the catalysts require high temperatures to operate effectively, and are often not adequately heated during intermediate phases.

Innovation Solution

A smoke box with an offset catalyst placement and integrated heat exchanger design, featuring removable insulation blocks, heat sinks, and an electrical heating element to maintain catalyst temperature, along with deflectors to slow down smoke and improve heat exchange, ensuring prolonged catalyst operation and efficient purification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the catalyst body is placed at the outlet of the fumes from the hearth, then the purification efficiency is improved, but the temperature of the gases and combustion fumes is insufficient to initiate and sustain the catalysis reaction during intermediate phases

Engineering Contradiction:
Improvepurification efficiencyVSAvoidtemperature of gases and combustion fumes
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent introduces a preheating zone with heating elements before the catalyst body to preliminarily raise the temperature of the gases and combustion fumes. This preliminary heating action ensures that the gases reach the required temperature for effective catalysis before contacting the catalyst, resolving the issue of insufficient temperature during intermediate phases while maintaining purification efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a preheating zone with heating elements as an intermediary component between the hearth outlet and the catalyst body. This intermediary element mediates the temperature transition, ensuring that the gases are properly heated before reaching the catalyst, thus enabling reliable catalysis operation across all operating conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the catalyst operates at high temperature, then the catalytic reaction efficiency is improved, but the catalyst cannot operate correctly during startup, extinguishing, or reduced speed phases when temperature is low

Engineering Contradiction:
Improvecatalytic reaction efficiencyVSAvoidoperational duration of catalyst
Core Design Contradiction:
ProductivityVSDuration of action of moving object

Solution Approach 1:

The preheating zone with heating elements performs preliminary heating action to raise the gas temperature to the catalyst's operating temperature range before the gases contact the catalyst. This ensures the catalyst can maintain high reaction efficiency during all operational phases including startup, extinguishing, and reduced speed conditions, thereby extending its effective operational duration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the temperature parameter of the gases and combustion fumes through the preheating zone before they reach the catalyst. By actively controlling and adjusting the temperature parameter to meet the catalyst's requirements, the system maintains high catalytic reaction efficiency across varying operating conditions and extends the catalyst's effective operational duration.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the smoke box is designed with a catalyst body, then the purification function is improved, but the access for cleaning and maintenance becomes difficult

Engineering Contradiction:
Improvepurification functionVSAvoidaccess for cleaning and maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the smoke box into distinct functional zones: a preheating zone, a catalyst zone, and an access zone. The access zone is specifically designed with openings that provide easy access to the catalyst body for cleaning and maintenance operations. This segmentation allows the purification function to be maintained while significantly improving ease of operation for maintenance activities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the maintenance access function from the overall smoke box structure by providing dedicated access openings and pathways. This allows maintenance personnel to easily access the catalyst body for cleaning and inspection without disrupting the purification function, effectively separating the operational and maintenance access requirements.

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

This configuration enhances catalyst efficiency, extends its operational time, facilitates easy maintenance, and improves purification efficiency by maintaining catalyst temperature, even at reduced fire rates or during startup/extinguishing phases, while also recovering additional heat.

Implementation Method 1

oxidation catalysts allowing, because of their high operating temperature, to calcine these particles and dust

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

the oxidation of the unburned gases and the recovery of the additional heat provided by the operation of the catalyst

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 3

the body of the smoke box comprising heat sinks in the form for example of fins, to transmit the heat to the air between the metal walls of the smoke box and those of the double jacket of the body of the heater

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

an electrical heating element to maintain catalyst temperature

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2370732B1Domestic heating appliance using solid fuel comprising a fume box
Publication Date: 2018.09.26 BAPAR
  • EP2370732B1 patent drawingFigure 1
  • EP2370732B1 patent drawingFigure 2
  • EP2370732B1 patent drawingFigure 3~4

AI summary

The invention relates to a fume box having a separation partition (16) in the upper portion thereof that comprises a removable catalyst block (17) offset relative to the inlet (10) and the outlet (8), and an intake passage that can be blocked by at least one insulating block. Deflectors slow down the gases and fumes and protect the catalyst block against falling soot and particle. The invention is particularly intended for manufacturers of domestic combustion heating appliances, in particular those using wood.