Catalyst Nozzle Heating for Carbon Nanotube Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing carbon nanotube (CNT) synthesis methods face challenges in achieving high-quality and high-yield CNTs due to difficulties in heating the catalyst raw material to sufficient temperatures within the catalyst raw material supplying nozzle, and contamination from the alumina component of the nozzle.
Innovation Solution
A carbon nanotube production device and method that involves setting the temperature of the inner portion of the catalyst raw material supplying nozzle higher than the temperature of the reaction field in the synthesis furnace, allowing for the thermal decomposition of the catalyst raw material and the generation of microscopic catalyst metal particles, which inhibits agglutination and enhances CNT growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If heating is performed from outside the catalyst raw material supplying nozzle with the tungsten wire, then the temperature of the outer portion of the nozzle can be raised, but it is difficult to set the temperature of the inner portion higher than the temperature of the reaction field
Solution Approach 1:
A heat transfer rod is introduced as an intermediary substance between the external heat source and the catalyst raw material. The rod conducts heat from the external heating unit to the inner portion of the nozzle, enabling the inner portion to reach temperatures higher than the reaction field without direct heating from outside.
Solution Approach 2:
The patent replaces the conventional external heating method with a heat transfer rod mechanism. This substitution allows for more efficient and controlled heat delivery to the inner portion of the nozzle, overcoming the limitations of external heating.
2Temperature
If the alumina-made catalyst raw material supplying nozzle is heated to a high temperature, then the catalyst raw material can be effectively heated, but the alumina component of the nozzle will mix into the CNTs synthesized
Solution Approach 1:
The heat transfer rod acts as a mediator that separates the heat source from the catalyst raw material supplying nozzle. This allows heat to be transferred to the catalyst raw material without the nozzle material itself being exposed to extreme temperatures that would cause contamination.
Solution Approach 2:
The heating function is extracted from the nozzle structure itself and transferred to a separate heat transfer rod. This separation allows the nozzle to remain at lower temperatures while still achieving effective catalyst raw material heating, preventing alumina contamination.
3Quantity of substance
If a catalyst raw material is thermally decomposed by raising the temperature to a high temperature, then microscopic catalyst metal particles can be generated, but the agglutination caused by collision between these particles occurs
Solution Approach 1:
The patent utilizes rapid temperature changes and controlled cooling rates to manage the decomposition process. By quickly raising the temperature for decomposition and then rapidly cooling, the system generates a high density of fine particles while minimizing agglutination through reduced residence time at high temperatures.
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 improves the quality and yield of CNTs by ensuring adequate heating of the catalyst raw material and preventing contamination, resulting in high-density, high-purity, and high-quality CNTs.
Implementation Method 1
a catalyst raw material is to be thermally decomposed by raising the temperature of the catalyst raw material in a catalyst raw material supplying nozzle to a high temperature
Implementation Method 2
the thermally decomposed catalyst raw material is then supplied to a synthesis furnace to be rapidly cooled to a chemical vapor deposition (CVD) temperature as a CNT growth temperature band so as to generate microscopic catalyst metal particles
Data Source
AI summary
Provided are a carbon nanotube production device and production method capable of realizing high-temperature heating of a catalyst raw material in a floating catalyst chemical vapor deposition (FCCVD) method, and improving the quality and yield of carbon nanotubes synthesized. A carbon nanotube production device 1 includes a synthesis furnace 2 for synthesizing carbon nanotubes; a catalyst raw material supplying nozzle 3 for supplying a catalyst raw material used to synthesize carbon nanotubes to the synthesis furnace 2; and a nozzle temperature adjusting unit 6 capable of setting a temperature of an inner portion 4 of the catalyst raw material supplying nozzle 3 higher than a temperature of a reaction field 5 of the synthesis furnace 2. By supplying to the synthesis furnace 2 the catalyst raw material that has been thermally decomposed after being heated to a temperate at which a catalyst metal will not yet be condensed, and by having the thermally decomposed catalyst raw material rapidly cooled to a CVD temperature at the synthesis furnace 2, microscopic catalyst metal particles will be generated at a high density in the space of the reaction field 5 such that carbon nanotubes having a small diameter can be vapor-grown at a high density.