Multi-tube Once-through Boiler Combustion Chamber Segmentation

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Solution Overview

Problem

The existing multi-tube once-through boiler has a sealed combustion chamber, making it difficult to clean and limiting the use of waste oil and solvent as fuel, and the current cleaning methods are insufficient for removing impurities from water tubes.

Innovation Solution

A horizontally extending cylindrical combustion chamber with a removable lid allows for easy cleaning, and an injection system mixes recovered oil and waste solvent with air to burn efficiently, while angled water tubes facilitate easy washing and fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the combustion chamber is sealed to maintain structural integrity and safety, then the boiler can operate safely, but cleaning becomes difficult and waste oil cannot be used as fuel

Engineering Contradiction:
Improvesafe operationVSAvoidcleaning accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The combustion chamber is segmented into a fixed main body and a removable lid portion. The lid can be detached to provide access for cleaning the combustion chamber interior, while the main body remains sealed during operation to ensure safety. This segmentation allows the chamber to be both safe during operation and accessible for maintenance.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the combustion chamber is sealed to prevent contamination, then the burning environment is controlled, but waste oil with residual ash cannot be used as fuel

Engineering Contradiction:
Improvecontrolled burning environmentVSAvoidfuel type flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

By separating the combustion chamber into a sealed main body and a removable lid, the system maintains a controlled burning environment during operation while allowing periodic removal of the lid for cleaning. This enables the use of waste oil and other fuels that generate residual ash, as the accumulated deposits can be removed without compromising the controlled environment during normal operation.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If chemical washing is used to clean impurities from water tubes, then some cleaning effect is achieved, but sufficient washing effect cannot be obtained

Engineering Contradiction:
Improvecleaning method simplicityVSAvoidwashing effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The water tubes are segmented with openable hole portions at both ends, allowing physical cleaning tools to be inserted and moved through the entire length of each tube. This mechanical cleaning approach complements or replaces chemical washing, providing sufficient washing effect by physically removing impurities that chemicals cannot effectively eliminate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hole portions in the headers are made openable, extracting the cleaning access points from the sealed structure. This allows cleaning tools and fluids to be introduced directly into the water tubes from both ends, enabling thorough cleaning that overcomes the limitations of external chemical washing methods.

Inventive Principle:
Principle #2Taking out (Extraction)

4Device complexity

If water tubes are arranged vertically in a sealed combustion chamber, then compact structure is achieved, but cleaning access is blocked

Engineering Contradiction:
Improvestructural compactnessVSAvoidcleaning accessibility
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The combustion chamber is divided into a sealed main body containing the vertically arranged water tubes and a separate removable lid. The lid provides access to the top of the vertically arranged tubes for cleaning, while maintaining the compact vertical arrangement within the sealed chamber during operation. This segmentation resolves the conflict between compact structure and cleaning accessibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lid is extracted as a separate removable component from the main combustion chamber body. This allows the lid to be removed for cleaning access while the main chamber maintains its compact sealed structure with vertically arranged water tubes. The extraction of the lid provides cleaning access without compromising the compact vertical arrangement.

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

Enables the use of waste oil as fuel, reduces fuel costs, and improves cleaning efficiency, allowing for effective utilization of waste materials while maintaining low carbon dioxide emissions.

Implementation Method 1

the combustion gas is supplied from the combustion gas passage 7 to the outside of the plurality of water tubes to heat and evaporate the boiler water within the water tubes

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the combustion gas is supplied from the combustion gas passage 7 to the outside of the plurality of water tubes to heat and evaporate the boiler water within the water tubes

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

by supplying fuel to a burner 10 installed within the combustion cylinder and burning the fuel, combustion gas is generated in a combustion chamber 9

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

the recovered oil and the waste solvent are adjusted in injection amount and mixed in the burner (10) using an injection unit (102) and an injection unit (202), whereby the recovered oil and the waste solvent can be burned efficiently

Methodology Applied
Scientific EffectMixing:

Data Source

PatentEP3940292B1Multi-tube once-through boiler
Publication Date: 2023.06.07 INO TAKAYUKI
  • EP3940292B1 patent drawingFigure 1
  • EP3940292B1 patent drawingFigure 2
  • EP3940292B1 patent drawingFigure 3

AI summary

In a multi-tube once-through boiler, a structure is obtained in which recovered oil and waste solvent can be used as combustion gas for generating consumed steam and cleaning of water tubes can be performed easily. In a multi-tube once-through boiler configured such that boiler water within water tubes is heated and evaporated to take out consumed steam, a combustion chamber (9) has a horizontally extending cylindrical shape, each water tube has an arc shape arranged on left and right sides of the combustion chamber (9), rows of water tubes arranged on the left and right of the combustion chamber (9) are respectively connected by linear left and right upper headers (1) provided at upper ends and linear left and right lower headers (2) provided at lower ends, a lid body (door) (22) is formed on one end side facing the combustion chamber (9) and a burner (10) for supplying combustion gas to the combustion chamber (9) is provided, and the burner (10) is provided with a recovered oil supply unit for supplying recovered oil, a waste solvent supply unit for supplying a waste solvent, an injected air supply unit, a combustion air supply unit, and a control unit for controlling the supply of the recovered oil, the waste solvent, the injected air, and the combustion air.