Process
Silicon carbide burner nozzle is the ideal fire kiln equipment which can be used in the ceramic, chemical, glass and metallurgy fields for the use of natural gas, liquefied gas and diesel fuel. It has the characteristics of high strength, no slag, no cracking, long service life and convenient replacement etc. It is also suitable for the roller kiln, tunnel kiln and shuttle kiln, which can effectively control the balance of temperature in the kiln.
It is made of UDC reactive bonded sintering silicon carbide ceramic SISIC, which has the properties of high strength, high hardness, good wear resistance and corrosion resistance. It can withstand thermal shock, high temperature and high pressure. It is widely applied in such kinds of kiln equipment as burner nozzle, desulfurization nozzle, sagger, crucible, radiation pipe, thermocouple protection piping, cooling pipe, plate, sealing, beam, special-shaped parts, blast nozzle and so on.
SISIC is a dense material containing SiC, mixed oxynitride SiC phase and oxide secondary phases (such as aluminium oxide). It is sintered at 2,000 deg C in an inert atmosphere with sintering additives such as Al2O3-Y2O3. This process is pressureless and does not involve any external pressure.
After forming, a thin layer of metallic silicon is formed on the surface, resulting in a dense material with excellent strength and fracture toughness. This material can be nitrided at 1,400 deg C, which changes the initial metallic silicon to a nitrided form of silicon carbide (SiC nitride).
The nitriding process is shrinkage-free and can be applied to any size of SSIC. In addition to fine-grained versions with grain sizes 5?m, coarse-grained versions with grain sizes up to 1.5 mm are also available.
This dense material is very popular for the manufacturing of kiln furniture such as beams, rolls and supports, as well as for various burner parts for direct and indirect combustion. Its high bending strength makes it especially suitable for such applications as furnaces, large boiers and other machinery.
The forming process involves the infiltration of liquid silicon into a preform of porous SiC-matrix, which contains free carbon. This technique allows production of complex shapes without any shrinkage and with very fine details. It is often used for shaped ceramic elements and combines the advantages of powder injection molding with the sintering process.
Structure
Silicon carbide (SiC) is an extremely durable and versatile material renowned for its chemical inertness, corrosion resistance, as well as thermal properties. Furthermore, SiC boasts a wide bandgap which makes it suitable for electronic and optical semiconductor applications like radiation sensors, optoelectronics, and biomedical devices.
SiC is composed of layers, with each atom bonding to four opposite types in a tetrahedral bonding configuration. This crystal structure can be broken down into several polytypes, each having its own distinct crystal structure and stacking sequence. This distinctive arrangement gives SiC its remarkable properties.
These properties include extreme hardness, superior wear and corrosion resistance, excellent thermal conductivity, a low coefficient of thermal expansion, and wide bandgap. These attributes have found applications across a range of industries such as abrasives and polishing materials to semiconductors and Schottky diodes.
One of the most remarkable properties of SiC is its sublimation ability: when heated sufficiently, it transforms from a solid to a vapor instead of melting. This property enables SiC to be used as an extremely high-temperature gas sensor.
Sublimation occurs due to a chemical reaction between oxygen atoms in SiC and nitrogen atoms in argon. These atomic bonds cause silicon carbide to break down into amorphous silica, freeing both oxygen and nitrogen atoms.
Furthermore, amorphous silica reacts with air to form oxides such as sulfur dioxide and carbon dioxide, which are then expelled through flue gas emissions.
During this process, oxygen and nitrogen molecules are replaced by hydrogen and carbon atoms, creating a hydrogen-rich vapor which can then be burned as fuel.
This process is an integral part of the production of silicon carbide products, and its success ensures the success of any such endeavor.
Characteristics
When applied in industrial heating processes, silicon carbide burner nozzle are often considered essential elements. Not only must it possess excellent thermal conductivity and the capacity for rapid heat transference, but its increased efficiency reduces fuel usage for heating kilns or furnaces.
Furthermore, it must be resistant to toxic fumes created by burning oil, gas or other liquid fuels. These fumes can corrode the lining of a kiln, drastically decreasing its life expectancy.
By switching to a silicon carbide tube instead of the standard nozzle for your kiln or furnace, you can improve its energy efficiency and save money on fuel costs. The tube encloses much of the flame which reduces radiant hot-spots inside, as well as generating greater velocities from flames within the kiln for even mixing of gases within it and faster energy transfers from fuel to product.
These advantages are especially crucial in the firing of sanitary and daily ceramics as well as electric porcelain, where direct radiant heat can be devastating to both product and kiln furniture. Thus, positioning the burner nozzle optimally within a kiln or furnace is an essential consideration.
Reaction bonded (SISiC) silicon carbide is an ideal material for manufacturing kiln nozzles and tubes due to its superior high temperature strength, oxidation resistance, and thermal shock resistance.
This material has many applications, from loose abrasives for lapping to mixtures used in high-temperature ceramic compositions.
Material can be molded into a variety of shapes through mechanical, chemical and heat-treating processes. Common shapes include rods, discs, plates, pipes and flanges.
These shapes can be employed as spray tools in a variety of kiln types, including tunnel kilns, edge kilns and roller kilns. Furthermore, they have the capacity to operate in industrial kilns that use open fire indirect heating or radiation pipe indirect heating systems.
Applications
Silicon carbide is an intriguing material with numerous applications. It finds use in semiconductors and as an abrasive. Furthermore, this mineral conducts electricity (and heat!) well while resisting corrosion from molten salts and acids.
SiC is widely used as a nozzle in industrial furnaces and kilns due to its high temperature resistance and strength. Additionally, SiC exhibits excellent oxidation resistance, has a low coefficient of thermal expansion, and chemical inertness.
In any industrial heating process, temperature regulation is of the utmost importance. Whether the fuel used is natural gas, LPG or oil, burner location can be a potential hotspot within the kiln which could cause overheating and damage to products as well as furniture inside of it.
IPS Ceramics can supply most sizes of reaction bonded silicon carbide (SISiC) or silicon infiltrated silicon carbide (SiSIC) tube to fit your existing kiln burners and offer improved temperature uniformity. The tube helps eliminate radiant hot-spots while increasing exhaust velocities for improved mixing within the kiln and rapid energy transfer.
silicon carbide burner nozzle are constructed from oxide, mullite, nitride and reaction bonded materials which offer excellent oxidation resistance while offering lower mass than traditional alloy steels. They come in either round or slotted configurations for high velocity burner applications.
These materials are highly durable and possess excellent heat transfer properties, making them perfect for direct heating of molten metal. Furthermore, these burner nozzles can be tailored to fit a variety of industrial uses in various shapes to meet specific requirements.
silicon carbide burner nozzle can dramatically enhance your kiln or furnace’s performance and dependability, as well as providing improved temperature uniformity. A well-designed burner nozzle will minimize radiated heating and prevent hot-spots in the chamber – which are hazardous to product and furniture inside of it.
IPS Ceramics provides a comprehensive selection of burner nozzles, working closely with your engineering team to make sure the one you select matches your furnace or kiln design. Our nozzles come in various diameters to accommodate various flame profiles and reduce the risk of overheating while providing accurate heat management in industrial furnaces.
