High-Pressure CO2 Quenching Apparatus for Large Workpieces

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Solution Overview

Problem

Current vacuum heat treatment technologies face limitations in quenching large workpieces effectively, as high-pressure gas quenching lacks sufficient thermal conductivity and liquid quenching often results in deformation, cracking, and pollution, while also being energy-inefficient and environmentally unfriendly.

Innovation Solution

A high-pressure liquid-state or supercritical-state quenching apparatus utilizing liquid carbon dioxide as a quenching medium, with a system that includes a working chamber, heating and cooling devices, vacuum pump, pressurization and circulation loops, and an integrated controller to regulate pressure and temperature, ensuring efficient and clean heat treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If high-pressure gas quenching is used, then pollution is avoided and heat-treatment deformation is reduced, but thermal conductivity is insufficient and only small or thin workpieces can be treated

Engineering Contradiction:
Improvepollution and deformationVSAvoidthermal conductivity
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The patent changes the physical state parameter of CO2 from gaseous to liquid or supercritical state under high pressure (7.3-30 MPa). Liquid or supercritical CO2 has significantly higher thermal conductivity than gaseous CO2, enabling effective heat transfer for large workpieces while maintaining the pollution-free advantage of gas quenching

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses CO2 in a composite state (liquid or supercritical fluid) that combines the advantages of both liquid (high thermal conductivity) and gas (low density, easy evaporation). This composite state allows CO2 to serve as an effective quenching medium for large workpieces without causing pollution

Inventive Principle:
Principle #40Composite materials

2Speed

If liquid quenching is used, then cooling speed is improved, but quenching deformation, cracking, and pollution occur

Engineering Contradiction:
Improvecooling speedVSAvoiddeformation, cracking, and pollution
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent changes the pressure parameter of CO2 to high pressure (7.3-30 MPa) to achieve liquid or supercritical state. This parameter change enables CO2 to provide fast cooling speeds like liquid quenching while avoiding the harmful effects of traditional liquid quenchants such as oil pollution, deformation, and cracking

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

CO2 provides an inert atmosphere during quenching that prevents oxidation and reduces quenching deformation and cracking. The inert environment protects the workpiece while providing the necessary cooling effect, eliminating the need for polluting liquid quenchants

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Temperature

If liquid quenching is used, then cooling effectiveness is improved, but steam produced during quenching pollutes the heating chamber

Engineering Contradiction:
Improvecooling effectivenessVSAvoidsteam pollution
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent utilizes the phase transition of CO2 from liquid or supercritical state to gaseous state during quenching. After quenching, CO2 evaporates completely leaving no residue or pollution in the heating chamber, unlike water-based quenching that produces steam and requires chamber cleaning

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

CO2 creates an inert atmosphere that prevents oxidation during heating and quenching processes. The inert environment protects the workpiece quality while the CO2 evaporates completely after use, leaving the heating chamber clean and maintaining vacuum degree

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

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 solution enables efficient quenching of large workpieces without deformation or pollution, using a safe, non-toxic, and recyclable medium that is energy-efficient and environmentally friendly, with automated control for precise operation and reduced waste.

Implementation Method 1

liquid carbon dioxide in the storage tank may enter the working chamber that is heated, to quench a target workpiece, and a status of carbon dioxide in the working chamber is controlled according to a set pressure-temperature relationship curve during quenching, wherein during liquid-state and supercritical-state quenching

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

a working chamber, internally provided with a heating device and a cooling device

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

a working chamber, internally provided with a heating device and a cooling device

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 4

a working chamber, internally provided with a heating device and a cooling device, and connected to a vacuum pump set

Methodology Applied
Scientific EffectVacuum: Vacuum

Data Source

PatentEP3342884B1High-pressure liquid-state or supercritical-state quenching apparatus
Publication Date: 2020.02.19 SHANGHAI YIBAI IND FURNACES CO LTD
  • EP3342884B1 patent drawingFigure 1~2

AI summary

Disclosed are a high-pressure liquid-state or supercritical-state quenching apparatus, comprising a working chamber, a heating device, a cooling device, a vacuum pump set, a storage tank, a buffer tank, a gas booster, a first pressure gauge, and a temperature controller. According to the Invention, vacuum liquid-state or supercritical-state quenching is implemented, which satisfies a quenching requirement of a large workpiece, and can also achieve an effect of high-pressure gas quenching. In addition, clean heat treatment is implemented, which avoids waste gas and waste water pollution, and is energy-saving and environmentally-friendly heat treatment.