Carbonaceous Grain Heat Treatment with Tubular Electrode

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heat treatment apparatuses for carbonaceous grains suffer from poor heat efficiency and non-uniform temperature distribution, leading to local temperature extremes, sublimation, and internal clogging, which hinder continuous operation and productivity.

Innovation Solution

A heat treatment apparatus with a columnar upper electrode and a tubular lower electrode, where the tubular structure is electrically connected to the upper end of the lower electrode, allowing for uniform current flow and resistant heat generation, reducing the rate of change in electrical resistivity, and incorporating gas injection to prevent clogging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a vertical electric furnace is used for continuous heating treatment by directly energizing carbonaceous grains, then productivity is improved, but temperature uniformity deteriorates and heat efficiency decreases

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidtemperature uniformity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The furnace is divided into multiple heating zones with separate electrodes (upper electrode, lower electrode, and side electrodes) that can be independently controlled. This segmentation allows different regions to be heated uniformly without causing local temperature extremes, resolving the contradiction between continuous operation and temperature uniformity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different electrodes are positioned to create optimized local heating conditions in different regions of the furnace. The upper and lower electrodes provide vertical heating while side electrodes address horizontal temperature distribution, ensuring uniform temperature throughout the carbonaceous grains during continuous processing.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If high filling rate is used to improve heat efficiency, then energy utilization improves, but electrical resistivity variation increases causing current drift

Engineering Contradiction:
Improveheat efficiencyVSAvoidcurrent distribution stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

Multiple electrodes are arranged to create equipotential surfaces that distribute current uniformly through the carbonaceous grains. This configuration ensures that even at high filling rates, the current flows evenly without concentrating in specific regions, preventing drift while maintaining high heat efficiency.

Inventive Principle:
Principle #12Equipotentiality

3Speed

If local high temperature occurs to improve heating speed, then processing efficiency improves, but sublimation and clogging occur

Engineering Contradiction:
Improveheating speedVSAvoidsublimation and internal clogging
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

Instead of applying excessive heat to a single location, the heating is distributed across multiple zones with controlled intensity. The multiple electrodes provide partial heating actions that collectively achieve the desired temperature without creating local extremes that would cause sublimation and clogging.

Inventive Principle:
Principle #16Partial or excessive 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 enables stable, long-term uniform heat treatment of carbonaceous grains, improving productivity and workability by preventing drift and internal clogging, while maintaining high temperature uniformity and quality of the treated products.

Implementation Method 1

heat treatment by directly energizing carbonaceous grains fed into a furnace body... carbonaceous grains are directly energized so that the carbonaceous grains are continuously subjected to heating treatment

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3309489B1Heat treatment apparatus for carbonaceous grains and method therefor
Publication Date: 2021.09.01 NIPPON ELECTRODE
  • EP3309489B1 patent drawingFigure 1
  • EP3309489B1 patent drawingFigure 2
  • EP3309489B1 patent drawing

AI summary

Provided are a heat treatment apparatus for carbonaceous grains and a method therefor allowing drifts and internal clogging in a direct energizing furnace to not occur, allowing heat treatment of the carbonaceous grains to be continued uniformly at high temperatures for a prolonged period of time, and allowing productivity and workability to be improved. On an upper part of a lower electrode 13, a conductive tubular structure 14 is electrically connected so as to surround an upper electrode 12. The rate of change between the grain electrical resistivity when grains are lightly filled and the grain electrical resistivity when the grains are packed is defined (1-packed/lightly filled) ×100, and the rate of change is 70% or less.