Compact Fire Tube Boiler Layout for Complete Combustion

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Solution Overview

Problem

Conventional fire tube boiler systems are complex, costly, and occupy large spaces, making them challenging to install and maintain, especially in limited areas, and often require multiple combustion stages to achieve efficient combustion.

Innovation Solution

A boiler system with a cylindrical housing containing a fire tube and two sets of tubes, where heated combustion gases flow sequentially from the fire tube to the first set of tubes and then to the second set, positioned above, allowing for complete combustion without the need for multiple combustion stages, and is designed to be compact for space-efficient installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple combustion stages with separate combustion chambers are used to accomplish complete combustion, then combustion efficiency is improved, but device complexity and footprint increase

Engineering Contradiction:

Improvecombustion efficiencyVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The combustion process is segmented into distinct zones within a single continuous combustion chamber: a primary combustion zone with restricted air supply for fuel-rich combustion, and a secondary combustion zone with enhanced air supply for fuel-lean combustion. This segmentation achieves complete combustion without requiring multiple separate chambers, thereby improving combustion efficiency while avoiding the complexity of multi-chamber systems.

Inventive Principle:

Principle #1Segmentation

2Reliability

If multiple combustion stages with separate combustion chambers are used, then complete combustion is achieved, but installation and maintenance complexity increase

Engineering Contradiction:

Improvecomplete combustionVSAvoidinstallation ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent merges the functions of multiple combustion chambers into a single integrated combustion chamber with spatially differentiated combustion zones. The primary and secondary combustion zones are arranged in series within one continuous chamber, allowing complete combustion to be achieved while simplifying installation and maintenance by eliminating the need for multiple separate chamber assemblies.

Inventive Principle:

Principle #5Merging (Combining)

3Loss of energy

If conventional fire tube boiler systems are used, then heat exchange is accomplished, but footprint and size are large

Engineering Contradiction:

Improveheat exchange efficiencyVSAvoidfootprint

Core Design Contradiction:

Loss of energyVSArea of stationary object

Solution Approach 1:

The patent transitions from a conventional horizontal arrangement of fire tubes to a vertical arrangement where combustion gases flow upward through the combustion chamber and then downward through heat exchange tubes. This vertical dimensionality change allows for more compact horizontal footprint while maintaining effective heat exchange surface area and thermal efficiency.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

4Loss of energy

If conventional fire tube boiler systems are used, then combustion heat transfer is achieved, but system cost increases

Engineering Contradiction:

Improvecombustion heat transferVSAvoidproduction cost

Core Design Contradiction:

Loss of energyVSEase of manufacture

Solution Approach 1:

The single combustion chamber serves multiple functions: it provides the primary combustion zone, the secondary combustion zone, and the transition passage for hot gases. This multi-functionality eliminates the need for separate combustion chambers and reduces the overall number of components, thereby simplifying manufacturing and reducing production costs while maintaining effective combustion heat transfer.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 achieves efficient combustion with reduced NOx formation and a smaller footprint, suitable for smaller spaces, while maintaining efficiency and simplicity in design and operation.

Implementation Method 1

combustion of an air-fuel mixture is accomplished using the burner

Methodology Applied

Scientific EffectCombustion: Combustion

Implementation Method 2

heated or hot combustion gases flow from the fire tube to the first set of tubes

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

boiler systems for hot water and steam applications

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentUS11662120B2Reduced size fire tube boiler system and method of operating same

Publication Date: 2023.05.30 CLEAVER BROOKS INC

AI summary

A boiler system having a generally cylindrical housing or shell includes a main or fire tube with a furnace or combustion chamber extending longitudinally near the bottom of the housing and a burner to accomplish combustion within the combustion chamber. The combustion chamber opens at its rear end to furnace tube sheet, and to a first set of tubes extending longitudinally of the boiler. The first set of tubes extends to and through the rear tube sheet of the boiler to a turnaround space, which transitions to a second set of tubes located above the combustion chamber and first set of tubes to generally span a length extending from the rear tube sheet of the boiler to the front tube sheet. The boiler system as disclosed has a reduced size while maintaining efficiency in steam and hot water applications.