Ejector Adhesion Prevention in Gasification Melting Furnaces

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Solution Overview

Problem

The circulation of combustion exhaust gas in gasification melting systems becomes unstable due to salts and slag droplets attaching to the inner walls of the ejector, causing clogging and channel narrowing.

Innovation Solution

The implementation of an adhesion-prevention unit with features such as adhered substance removal portions that supply vibration or air to the inner wall surface, a swirling separation portion to centrifugally separate incorporated substances, and a cooling system to solidify volatilized salts, along with multiple ejectors and air film forming portions to prevent attachment, ensures stable gas circulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the ejector is used to circulate combustion exhaust gas through the melting furnace, then the combustion exhaust gas can be circulated to maintain the slag tap at high temperature, but salts and slag droplets attach to the inner wall surface of the ejector causing clogging and channel narrowing

Engineering Contradiction:
Improvestability of combustion exhaust gas circulationVSAvoidattachment of incorporated substances to ejector inner wall
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies mechanical vibration through a vibration motor mounted on the ejector to prevent incorporated substances (salts and slag droplets) from attaching to the inner wall surface. The vibration disrupts the adhesion process, causing particles to remain suspended in the gas flow rather than settling on surfaces, thereby maintaining clear circulation channels and preventing clogging.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent introduces a vibration motor as an intermediary device that mediates between the combustion exhaust gas flow and the incorporated substances. The vibration motor creates dynamic conditions in the ejector that prevent direct contact and attachment between salts/slag droplets and the inner wall surface, acting as a protective intermediary mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If the combustion exhaust gas is circulated through the ejector at high temperature, then the slag tap remains molten, but the incorporated substances accumulate and narrow the channel

Engineering Contradiction:
Improvetemperature of combustion exhaust gasVSAvoidcross-sectional area of ejector channel
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The vibration motor generates continuous mechanical vibration in the ejector body, creating dynamic flow conditions that prevent incorporated substances from settling and accumulating on the inner wall surface. This maintains the effective cross-sectional area of the channel open, preventing narrowing even at high temperatures where attachment is most likely to occur.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The vibration motor performs preliminary action by continuously preventing attachment before it can occur. By maintaining constant vibration, the system proactively prevents incorporated substances from adhering to the inner wall surface, thereby preventing channel narrowing before it happens rather than addressing it after accumulation occurs.

Inventive Principle:
Principle #10Preliminary action

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 effectively prevents clogging and maintains stable combustion exhaust gas circulation by removing adhered substances and reducing the attachment of incorporated materials to the ejector's inner surfaces, ensuring continuous operation without channel narrowing.

Implementation Method 1

the adhered substance removal portion preferably supplies vibration to the inner wall surface of the ejector

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

a swirling separation portion that is provided upstream of the contraction portion, swirls the introduced combustion exhaust gas so as to form a swirling flow, and centrifugally separates any incorporated substance included in the swirling flow

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Implementation Method 3

The cooling system cools the inner wall along which the swirling flow of the combustion exhaust gas flows

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 4

an air film forming portion that forms an air film along the inner wall surface of the ejector

Methodology Applied
Scientific EffectAir film formation: Air Lubrication

Data Source

PatentEP2581661B1Melting equipment
Publication Date: 2019.05.01 MITSUBISHI HEAVY IND ENVIRONMENTAL & CHEM ENG CO LTD
  • EP2581661B1 patent drawingFigure 1
  • EP2581661B1 patent drawingFigure 2
  • EP2581661B1 patent drawingFigure 3~4

AI summary

The melting equipment has a melting furnace that combusts and melts ash, a secondary combustion chamber disposed above the melting furnace, a slag extraction chute that guides slag generated in the melting furnace downward, a bypass channel (20) that connects the slag extraction chute and the secondary combustion chamber, an ejector (22) that is provided between the bypass channel (20), has a contraction portion (23) at which the channel cross sections are narrowed, and suctions the combustion exhaust gas (G) into the bypass channel (20), and an adhesion-prevention unit (31) (41) that prevent an incorporated substance that incorporates into the combustion exhaust gas (G) from attaching to the inner wall surface (21a) of the ejector (22).