Industrial Furnace Gas Recirculation and Pressure Control

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Solution Overview

Problem

Industrial furnaces face thermal and gas losses due to continuous flushing processes, which are inefficient and result in unused carbon potential being burned off, while existing solutions for gas recirculation and pressure control do not effectively manage gas flow to minimize losses and ensure safety.

Innovation Solution

A method and device that control process gases by opening the burn-off point only as needed, using a sequence of valve operations to supply and burn off flushing gas, regulate furnace pressure, and maintain it, with independent C potential control, and a gas-tight overpressure valve for controlled pressure reduction, minimizing gas usage and ensuring safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If continuous flushing process is used to supply protective gas to the furnace, then the carbon potential is regulated and the furnace atmosphere is maintained, but thermal loss and gas loss occur when the protective gas is flared off at the burn-off point

Engineering Contradiction:
Improvefurnace atmosphere controlVSAvoidthermal loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent recovers and recirculates the protective gas that would otherwise be flared off at the burn-off point. The gas is redirected through a recirculation system back into the furnace chamber, maintaining the carbon potential while eliminating the need for continuous fresh gas supply and flaring, thus reducing both thermal loss and gas loss

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The recirculation system maintains continuous presence of protective gas in the furnace chamber without interruption. The gas flows continuously from the chamber through the recirculation path and back, ensuring constant atmosphere control while eliminating the start-stop nature of continuous flushing and burning

Inventive Principle:
Principle #20Continuity of useful action

2Reliability

If continuous flushing process is used to supply protective gas to the furnace, then the furnace atmosphere is maintained, but actual gas loss occurs which has to be compensated for by new components of the process gas

Engineering Contradiction:
Improvefurnace atmosphere controlVSAvoidgas loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The protective gas is recovered from the furnace chamber and recirculated back through the system. This eliminates the need to continuously supply new gas components to compensate for losses, as the same gas is reused repeatedly, preventing both gas loss and the associated resource waste

Inventive Principle:
Principle #34Discarding and recovering

3Loss of substance

If the burn-off point is sealed gas-tight with a valve, then gas losses are reduced, but pressure control and safety requirements must be met

Engineering Contradiction:
Improvegas lossVSAvoidpressure control and safety
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent introduces a pressure control valve as an intermediary device between the sealed burn-off point and the furnace chamber. This valve acts as a mediator that maintains the gas-tight seal while providing controlled pressure regulation and safety relief capabilities, balancing both gas loss prevention and operational safety requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The pressure control system incorporates feedback mechanisms that continuously monitor furnace pressure and adjust the valve positioning accordingly. This feedback loop ensures that the burn-off point remains sealed to prevent gas loss while automatically maintaining pressure within safe operating limits

Inventive Principle:
Principle #23Feedback

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 reduces gas losses, maintains optimal furnace pressure, and ensures safety by only burning off the necessary amount of gas, enhancing the efficiency of gas recirculation and reducing thermal losses, while allowing for precise control of the carbon potential and pressure management.

Implementation Method 1

a quantity of a flushing gas of the gas mixture of the respective process gas is supplied to the industrial furnace and then burned off

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

the industrial furnace to a preset furnace pressure is regulated and permanently recorded via the pressure gauge

Methodology Applied
Scientific EffectPressure control:

Implementation Method 3

the depleted gas is now not burned, but is conducted by means of a circulator into said treatment room

Methodology Applied
Scientific EffectGas recirculation:

Implementation Method 4

the components carbon dioxide, oxygen and water vapor react with a supplied hydrocarbon in the processing room of an industrial furnace to form carbon monoxide and hydrogen again, with catalytic support

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 5

the components carbon dioxide, oxygen and water vapor react with a supplied hydrocarbon in the processing room of an industrial furnace to form carbon monoxide and hydrogen again

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentEP2336372B1Method and device for regulating process gases for the thermoforming of metallic materials/workpieces in industrial ovens
Publication Date: 2016.03.02 IPSEN INTERNATIONAL GMBH
  • EP2336372B1 patent drawingFigure 1
  • EP2336372B1 patent drawingFigure 2

AI summary

The method for controlling process gas for heat treatment of metallic materials/workpieces in industrial furnace (1), which comprises a treatment chamber (2), a combustion point (4) with a first valve (4.1) and a regulator (5) with pressure gauge, comprises processing the process gas in a component of a respective gas mixture in a limitable area and/or then utilizing as flushing gas in a rinse gassing. A quantity of the flushing gas of the gas mixture of the respective process gas is controllably guided to the industrial furnace and then burned in open combustion valve. The method for controlling process gas for heat treatment of metallic materials/workpieces in industrial furnace (1), which comprises a treatment chamber (2), a combustion point (4) with a first valve (4.1) and a regulator (5) with pressure gauge, comprises processing the process gas in a component of a respective gas mixture in a limitable area and/or then utilizing as flushing gas in a rinse gassing. A quantity of the flushing gas of the gas mixture of the respective process gas is controllably guided to the industrial furnace and then burned in open combustion valve. The rinsing gas of the combustion valve is closed, where the industrial furnace is controlled on a preset furnace pressure and is recorded permanently over the pressure gauges in such a way that a fresh gas valve is controlled so that a quantity of a fresh gas of the respective gas mixture of the process gas is provided necessary to a pressure reduction. The fresh gas valve is controlled in such a way that the pressure is recorded and held over the pressure gauges, where the combustion valve remains in the phase. The rinse gassing is activated and regulated. An excess pressure valve of the combustion point is opened to the pressure reduction controlled over a fixed limit value in large increase in pressure. A C-level required for the process independent from the pressure control of the furnace control is regulated by a C-potential regulator (3) and is adjusted over a gas- and air supply. The method is used for charge-wise heat treatment of the metallic materials/workpieces in the industrial furnace, which works according to break through principle. The activated rinse gassing is adjusted before a charge movement, a charge exchange or the loading of a charge. The controlled rinse gassing is activated until a rinsing time is expired or a selected carbon monoxide-level is reached. The requirement of the rinse gassing is initiated from the furnace control to liberate the furnace chamber of remnants of foreign gases. The method is used in inert gas recirculation systems for a gas carburization in which the components such as carbon dioxide, oxygen and water vapor is supplied with a hydrocarbon again to the carbon monoxide and hydrogen in an internal or an external treatment chamber of the industrial furnace in recirculating manner. A hand shifter and a shut-off valve are used for adjusting different combustion quantities in different combustion strands. An independent claim is included for a device for controlling process gases for heat treatment of metallic materials/workpieces in industrial furnace.