Gasification Furnace Fuel Level Control for Tar Reduction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In gasification systems, insufficient air supply to the central portion of the fuel in the inner cylinder leads to tar production, and excessive fuel accumulation causes combustion inefficiencies and clinker formation due to hot spots and cool spots.

Innovation Solution

A gasification system with a fuel detection unit and control apparatus that maintains the fuel level within a target range in the inner cylinder, preventing fuel bridging and ensuring adequate air distribution, which reduces tar production and clinker formation by controlling the fuel supply based on combustion state and using a constricted portion to enhance air flow and temperature uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If air is supplied from the side of the furnace through a nozzle toward the center, then the fuel can be gasified, but hot spots are formed where ash melts to produce clinker

Engineering Contradiction:
Improvefuel gasification efficiencyVSAvoidclinker formation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a water spray system as an intermediary substance to cool the fuel and air mixture before it reaches the combustion zone. The water evaporates and absorbs heat, preventing hot spots from forming where ash would otherwise melt and create clinker. This mediator approach allows continuous fuel supply while avoiding the harmful thermal effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the temperature parameter by injecting water spray into the fuel-air mixture, thereby reducing the local temperature in the nozzle area. This parameter change prevents the ash melting point from being reached, eliminating clinker formation while maintaining adequate fuel gasification through controlled combustion downstream.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If fuel is accumulated excessively in the inner cylinder, then the fuel level increases, but fuel bridging occurs and combustion efficiency degrades

Engineering Contradiction:
Improvefuel accumulation levelVSAvoidcombustion efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent implements a feedback control system using a level sensor to detect the fuel level in the inner cylinder. When the fuel level reaches a predetermined height, the system automatically stops fuel supply. This feedback mechanism prevents excessive fuel accumulation and bridging, maintaining optimal combustion efficiency by ensuring proper air-fuel mixing.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent creates a dynamic fuel supply system where the fuel feed rate is adjusted based on real-time fuel level detection. The system transitions from static continuous feeding to dynamic controlled feeding, allowing the fuel level to be maintained within an optimal range that prevents bridging while ensuring sufficient fuel for efficient combustion.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the inner cylinder lower end opening is plugged by fuel, then fuel gasification can occur, but air supply to the central portion becomes insufficient leading to tar production

Engineering Contradiction:
Improvefuel gasificationVSAvoidtar production
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the fuel bed structure by maintaining a specific fuel level that creates distinct zones: an upper gasification zone and a lower combustion zone. This segmentation ensures that air can penetrate to the central portion of the fuel bed through controlled pathways, preventing tar formation while maintaining efficient gasification in the upper section.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality control by maintaining different fuel levels and air distribution characteristics in different zones of the inner cylinder. The fuel level is controlled to ensure adequate air supply to the central region while maintaining sufficient fuel accumulation at the periphery for efficient gasification, thus eliminating tar production without compromising productivity.

Inventive Principle:
Principle #3Local quality

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 approach stabilizes gasification, minimizes tar production, and prevents clinker formation by maintaining optimal fuel levels and air distribution, achieving efficient gasification with reduced tar and clinker formation.

Implementation Method 1

a fuel detection unit configured to detect, as an inside furnace level (H), an accumulated height of the fuel accumulated inside the inner cylinder

Methodology Applied
Scientific EffectLevel detection:

Implementation Method 2

a control apparatus configured to determine the inside furnace level (H) and control the fuel supply apparatus... obtain a deviation (value (H1) and the inside furnace level (H))

Methodology Applied
Scientific EffectFeedback control: Feedback

Implementation Method 3

a gasification furnace configured to gasify fuel... burn the fuel inside the inner cylinder

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

air as a gasification agent is supplied from a lower portion of a furnace and the air flows upward

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2765177B1Gasification system
Publication Date: 2017.11.22 YANMAR CO LTD
  • EP2765177B1 patent drawingFigure 1
  • EP2765177B1 patent drawingFigure 2
  • EP2765177B1 patent drawingFigure 3~4

AI summary

The present invention includes a gasification furnace that gasifies fuel, and a fuel supply apparatus that supplies the fuel to the gasification furnace. The gasification furnace includes an inner cylinder to introduce the fuel and air into the gasification furnace. A height from a lower end opening in the inner cylinder to a predetermined height position is set as an inside furnace level target value H1. The present invention also includes: a detection unit that detects an accumulated height of the fuel accumulated inside the inner cylinder as an inside furnace level H; and a control apparatus that obtains a deviation between the inside furnace level target value H1 and the inside furnace level H, and that controls the fuel supply apparatus according to the deviation so that the inside furnace level is coincident with the inside furnace level target value.