Rotating Flow Diverter Cone for Shaft Furnace Gas Distribution

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Solution Overview

Problem

Conventional direct reduction (DR) processes face challenges in maintaining burden/product consistency, particularly in the transition and cooling zones of the shaft furnace, where clumping and uneven gas distribution can occur, affecting the quality of cold direct reduced iron (CDRI), hot direct reduced iron (HDRI), and hot briquetted iron (HBI).

Innovation Solution

The introduction of an extended flow diverter cone, which replaces the conventional 'China hat' in the transition zone, featuring a dual-cone configuration with a shorter upwards-pointing cone portion in the transition zone and a longer downwards-pointing cone portion in the cooling zone, allowing for improved gas saturation and uniform material flow. This cone can pivot and includes gas injection ports for enhanced gas distribution, with burden feeders above and below to maintain uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a conventional fixed China hat flow interrupter is used in the transition zone, then burden clumping is broken up, but gas distribution remains uneven and burden/product consistency deteriorates

Engineering Contradiction:
Improveburden/product consistencyVSAvoidgas distribution uniformity
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The flow diverter cone is made rotatable about a vertical axis, transforming the static China hat structure into a dynamic one. The cone can rotate to different angular positions (e.g., 0°, 45°, 90°, 135°) to adapt to varying burden flow patterns and gas distribution needs, thereby maintaining both clumping prevention and uniform gas distribution throughout operation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The flow diverter system is divided into multiple functional zones: the upper cone portion for breaking up clumps in the transition zone, the lower annular cone portion for distributing gas in the cooling zone, and the rotatable mechanism for adjusting orientation. This segmentation allows each part to optimize its function while working together to improve overall burden/product consistency

Inventive Principle:
Principle #1Segmentation

2Stability of the object's composition

If the flow diverter structure is extended into the cooling zone, then burden/product consistency improves, but device complexity increases

Engineering Contradiction:
Improveburden/product consistencyVSAvoidflow diverter structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The upper cone and lower annular cone are merged into a single integrated flow diverter assembly that rotates as one unit. This combining of functions into a single rotatable structure reduces the number of separate components and actuators needed, thereby limiting the increase in device complexity while still providing extended functionality into the cooling zone

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotatable flow diverter cone serves multiple functions: it acts as a flow interrupter in the transition zone, a gas distributor in the cooling zone, and an adjustable mechanism that can adapt to different operating conditions. This multi-functionality justifies the extended structure by consolidating multiple roles into one component

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Quantity of substance

If gas injection ports are added to the flow diverter, then gas saturation improves, but manufacturing complexity increases

Engineering Contradiction:
Improvegas saturationVSAvoidflow diverter manufacturing complexity
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The flow diverter cone incorporates porous walls that allow gas to permeate through the entire surface area of the cone. This porous structure provides extensive gas injection capability without requiring numerous discrete ports, thereby improving gas saturation while keeping the manufacturing process relatively simple

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

Gas is injected through the porous walls of the rotating cone, utilizing fluid dynamics to distribute reducing gas uniformly across the burden. The rotation of the cone enhances gas distribution by continuously changing the injection pattern, improving gas saturation efficiency without complex injection systems

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 dual-cone flow diverter promotes uniformity and prevents clumping in both the transition and cooling zones, enhancing the production efficiency and quality of DRI, especially in 'hot' applications by ensuring consistent burden/product flow and improved gas distribution.

Implementation Method 1

allowing for better saturation, and may be followed in sequence by additional similar gas injection ports

Methodology Applied
Scientific EffectGas flow distribution: Convection

Implementation Method 2

a shaft furnace for producing metallic direct reduced iron (DRI) from iron-containing pellets or lumps and reducing gas disposed therein, comprising: a circumferential outer wall defining a top interior reducing zone, a middle interior transition zone, and a bottom interior cooling zone, wherein the iron-containing pellets or lumps travel downwards through the top interior reducing zone, the middle interior transition zone, and the bottom interior cooling zone as the iron-containing pellets or lumps encounter the upward-flowing reducing gas

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 3

a shaft furnace for producing metallic direct reduced iron (DRI) from iron-containing pellets or lumps and reducing gas

Methodology Applied
Scientific EffectDirect reduction reaction: Reduction

Data Source

PatentEP3535424B1Direct reduction process and shaft furnace utilizing an extended flow diverter cone
Publication Date: 2023.12.20 MIDREX TECHNOLOGIES INC
  • EP3535424B1 patent drawingFigure 1
  • EP3535424B1 patent drawingFigure 2

AI summary

A shaft furnace for producing metallic direct reduced iron (DRI) from iron-containing pellets or lumps and reducing gas disposed therein, including: a circumferential outer wall defining a top interior reducing zone, a middle interior transition zone, and a bottom interior cooling zone, wherein the iron-containing pellets or lumps travel downwards through the top interior reducing zone, the middle interior transition zone, and the bottom interior cooling zone as the iron-containing pellets or lumps encounter the upward-flowing reducing gas and one or more other gases; and a flow diverter disposed along a centerline of the circumferential outer wall including a convex-upwards upper tapering section disposed in the middle transition zone defined by the circumferential outer wall coupled to a convex-downwards lower tapering section disposed in the bottom cooling zone defined by the circumferential outer wall.