| Customization: | Available |
|---|---|
| After-sales Service: | on-Line Service |
| Warranty: | 1 Years |
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Purpose:
Our advanced furnace tube is pivotal in serving as the inner lining for a range of experimental electric furnaces. It excels in isolating heating elements from test materials, ensuring safe enclosure of the heating zone while securely holding test substances. This indispensable component is extensively utilized in high-temperature testing across various industries, including coal testing, metallurgical powder analysis, and chemical/glass laboratory settings.
Material & Manufacturing:
Crafted with precision, our Corundum furnace tubes are primarily composed of premium fused alumina, and are available in two superior types:
Ultra-fine powder-bonded
Clay-bonded
Each tube is tailored to meet specific user requirements, ensuring optimal performance characteristics such as operating temperature, wear resistance, and chemical corrosion resistance.
Dimensions:
Outer diameter ranges from 15-200 mm, offering versatility in application.
Length options vary between 100-2000 mm to suit diverse needs.
Wall thickness can be customized from 3-15 mm, ensuring structural integrity.
Usage Guidelines:
For optimal results with high-temperature testing equipment, always ensure a gradual heating and cooling process to effectively minimize internal stress due to thermal expansion or contraction. This practice significantly reduces the risk of cracking, thereby extending the lifespan of the tube.
Composition:
Expertly constructed from porous fused alumina, these crucibles are renowned for their exceptional durability and unmatched heat resistance.
Applications:
Ideal for melting samples in the presence of weak alkaline fluxes such as anhydrous NaCO, ensuring reliable results.
Not suitable for use with strong alkaline fluxes like NaO, NaOH, or acidic fluxes such as KSO, protecting against undesired reactions.
Boasting an impressive 99.70% purity of corundum, these crucibles offer:
Max short-term temperature tolerance of up to: a stunning 1800°C,
alongside robust mechanical strength in both oxidizing and reducing atmospheres.
With high thermal conductivity and minimal thermal expansion, they are engineered for excellence.
Operating range: 1650-1700°C, catering to high-demand environments.
Displaying exceptional high-temperature insulation, they remain
chemically inert to air, steam, hydrogen, and carbon monoxide, even up to 1700°C.
99.35% Corundum
Max short-term temperature: capability of up to 1750°C,
Operating range: 1600-1650°C, ensuring reliable performance.
Stable even in challenging oxidizing and reducing atmospheres,
85.00% High-Alumina
Max short-term temperature: 1400°C
Operating range: 1290°C, providing dependable thermal insulation and mechanical strength.
Exhibiting good insulation and mechanical strength in oxidizing and reducing environments,
they feature high thermal conductivity and low thermal expansion, maintaining stability and reliability.
Resistant to chemical reactions with air, steam, hydrogen, carbon monoxide, and more, they ensure safe operations.
Perfectly suitable for Enjoy unparalleled durability with our RJ New Corundum Furnace Tube Crucible, designed for long-term use, ensuring consistent performance over time. Experience the pinnacle of stability under stable temperature conditions, providing you with reliable and consistent results.
Immerse yourself in the world of Quartz glass tubes, an extraordinary industrial technical marvel crafted from silicon dioxide (SiO). This remarkable material boasts an array of unparalleled physical and chemical properties:
With an impressive softening point around ~1730°C, it's engineered for enduring extreme conditions.
Long-term use up to 1100°C, ensuring reliability in demanding environments.
For short bursts, it withstands a scorching maximum of: 1450°C, setting a new standard for high-temperature performance.
Nearly impervious to all acids, with the sole exception of (HF), ensuring longevity and resilience..
Boasting superior acid resistance, it's
30× stronger than ceramics and
150× more robust than stainless steel, offering extraordinary durability.
Unmatched high-temperature chemical stability,setting it apart from all other engineering materials.
Featuring an incredibly low thermal expansion coefficient,
this material withstands rapid temperature changes like heating to 1100°C and immersing in room-temperature water without any cracking.
Enjoy superior light transmission across the UV to infrared spectra,making it an optimal choice for various applications.
With visible light transmittance exceeding 93%, and
UV spectrum transmittance reaching up to 80%+, it offers outstanding clarity.
With a resistivity that's 10,000× higher than ordinary glass, it excels in providing superb insulation even under high temperatures.
An ideal choice for ensuring safe and efficient operations.
Usage & Properties
Designed for use up to 1450°C, and available inboth transparent and opaque variants to fit your specific needs. Discover the numerous advantages:
including high purity, outstanding temperature resistance, and large size with precision, providing excellent thermal insulation, energy-saving benefits, and stable quality. Perfectly suited for demanding applications..
Chemical Compatibility
Excludes compatibility with HF , highlighting its resilient structure.
Reacts with caustic alkalis and alkali metal carbonatesat high temperatures, necessitating mindful usage.
Suitable Fluxes
Optimally designed for melting samples using KSO (potassium pyrosulfate) or KHSO (potassium bisulfate),promising versatility in applications.
Additionally, it can be adeptly used with NaSO (sodium pyrosulfate, pre-dried at 212°C) for comprehensive sample processing.
Quartz Crucible Usage & Maintenance
Primary chemical composition: Silicon dioxide (SiO).
Standing resilient against most acids, except for HF, our product showcases remarkable chemical inertness. However, it does react with caustic alkalis and alkali metal carbonates.
This innovative corundum furnace tube crucible boasts exceptional thermal stability, ensuring reliability in high-temperature environments.- Enjoy the convenience of heating directly over an open flame, thanks to the product's robust design.
Though as delicate as glassware, this crucible demands careful attention to avoid damage.- Handle with utmost care to maintain its integrity and longevity.
Permissible fluxes:
KHSO (potassium bisulfate), NaSO (sodium pyrosulfate, pre-dried at 212°C), among others, can be used safely.
Maximum melting temperature: 800°C. Designed to withstand intense heat, offering reliable performance up to this point.
Handling Precautions
Brittle and fragile- Exercise care to prevent breakage during handling and use.
Cleaning
Our crucible can be effortlessly cleaned with dilute inorganic acids (except HF),ensuring ease of maintenance.
Material Characteristics: Hard and brittle, this crucible exhibits impressive resistance to thermal shock and retains its shape at high temperatures. Additional physical properties include:
Density: 3.2 g/cm³ ensures a robust build.
Mohs Hardness: 9.5 reflects its tough exterior.
Specific Heat: 0.17 kcal/kg·°C provides efficient thermal management.
Thermal Conductivity: 20 kcal/m·h·°C offers excellent heat dispersion.
Linear Expansion Coefficient: 5×10 (m/°C) ensures minimal expansion, maintaining structural integrity.
Our silicon carbide rods display outstanding chemical stability and formidable acid resistance. Yet, they are susceptible to alkaline corrosion under elevated temperatures.
When used long-term above 1000°C, silicon carbide rods undergo reactions with oxygen and water vapor, detailed as follows:
SiC + 2O → SiO + CO
SiC + 4HO → SiO + 4H + CO
These reactions incrementally boost SiO content, resulting in heightened resistance and progressive aging.
Excessive water vapor accelerates SiC oxidation, causing H to react with O, forming HO anew and perpetuating a harmful cycle that diminishes rod longevity.
Nitrogen (N) acts as a protective barrier against SiC oxidation below 1200°C but engages in reactions with SiC above 1350°C, leading to decomposition.
Chlorine (Cl) fully decomposes SiC, necessitating caution in chlorine-rich environments.
Fragility: Despite their hardness, silicon carbide rods are brittle-avoid impacts or vibrations to preserve their integrity during transport and use.
Heating Zone Length: Ensure the heating section corresponds with the furnace chamber's width, preventing damage by avoiding extension into the furnace wall.
Cold End Length: The cold end should match the wall thickness plus 50-150 mm extension outside the wall for effective cooling and secure clamping.
Furnace Hole Diameter: Should be 1.4-1.6× The outer cold end diameter holds its own significance. Avoid constricting its thermal expansion with tight holes or fillers, which might lead to detrimental breakage. Simply let those rods breathe by installing them with ease. 360° rotation.
Spacing Requirements:
Distance to heated materials/furnace wall: ≥ 3× heating zone diameter.
Center-to-center spacing between rods: ≥ 4× heating zone diameter.
Electrical Connection:It's crucial to manage contact resistance to prevent cracking.
Resistance Matching: Before embarking on use, ensure you group rods that possess similar resistance values.
Connections: Employ aluminum braids or foil to securely link the cold ends to the main circuit. Keep clamps firm and steadfast.
Furnace Preheating: Introduce heat gradually to new or long-idle furnaces using either old rods or alternative heat sources.
Storage: Ensure rods remain dry to protect the cold end's precious aluminum layer from moisture degradation.
Voltage Control: Employ a voltage regulator, commencing at 50% of the operating voltage. Gradually increase to prevent thermal shock.
Operating Limits:
Optimize surface load and temperature meticulously.
Max temperature: ≤1650°C.
Steer clear of chemical reactions within corrosive gas environments.
Replacement: Switch rods with those of similar resistance or, alternatively, replace the entire set. If resistance is appropriate, previously used rods can seamlessly make a comeback.
Avoid Molten Metal: Contact with molten metal spells disaster with breakage.
Avoid Alkalis: Alkali metals and oxides are corrosive foes to the rods.
Regular Checks: Diligently monitor amperage, voltage, and temperature, and inspect for:
Loose/oxidized clamps,
Rod fractures,
Uneven heating (red-hot zones).
| Property | Value |
|---|---|
| Bulk Density | 5.5 g/cm³ |
| Flexural Strength | 15-25 kg/cm² |
| Vickers Hardness | (HV) 570 kg/mm² |
| Porosity | 7.4% |
| Water Absorption | 1.2% |
| Thermal Elongation | 4% |
In high-temperature oxidizing atmospheres, silicon molybdenum rods unveil a protective quartz (SiO) layer, shielding against further oxidation. When the element's temperature transcends 1700°C, this quartz layer gracefully melts. Yet, in continual oxidizing atmospheres, it magically regenerates, standing guard once again.
Important Note: It is imperative to avoid using silicon molybdenum rods for extended periods within the 400-700°C range due to the risk of low-temperature oxidation. Such oxidation can severely compromise the structural integrity by deteriorating the rods into powder form.
| Atmosphere | Continuous Use Temp. | Short-term Max Temp. |
|---|---|---|
| NO, CO, O, Air | 1700°C | 1800°C |
| He, Ar, Ne | 1650°C | 1750°C |
| SO | 1600°C | 1700°C |
| CO, N | 1500°C | 1600°C |
| Moist H | 1400°C | 1500°C |
| Dry H | 1350°C | 1450°C |
Silicon molybdenum (Si-Mo) rods demonstrate a slight softening phenomenon at elevated temperatures exceeding 1500°C. Conversely, they exhibit increased hardness and brittleness when subjected to lower temperatures. To effectively manage thermal stress and accommodate the natural thermal expansion and contraction tendencies, a free-hanging vertical installation is highly recommended. This strategic installation method also provides the added benefit of facilitating the hot replacement of rods, eliminating the need for waiting until the furnace cools down.
Furnace Lining Material
Use only corundum bricks that have a FeO content of less than 1%. Higher concentrations of FeO can react adversely with the protective SiO layer, resulting in the formation of low-melting-point silicates. This process accelerates the degradation of the rods.
Cold-End Sealing
The leakage of hot gas from the cold ends can significantly increase heat loss and pose a risk of damaging the conductive clamps and leads. Asbestos clamps are ideally suited for effective insulation purposes.
Handling Fragility
Si-Mo rods are inherently brittle and exhibit low flexural strength. It is crucial to handle them with care and avoid impacts during installation.
Secure asbestos or ceramic clamps carefully prior to connecting the conductive straps. Do not overtightento prevent potential damage.
Mounting with Insulating Bricks
Utilize foamed corundum split bricks to house the rods, thereby minimizing the mechanical stress during both installation and removal processes.
Furnace Roof Installation
Carefully insert the rod-mounted bricks into the pre-cut slots of the furnace roof. Ensure the bricks extend beyond the roof surface to facilitate easier disassembly and maintenance.
Conductive Strap Connection
Connect the straps securely to the pre-installed brackets. Be cautious to avoid tension or unnatural bends as these can induce stress on the system.
Anti-Sagging Measure
Apply refractory mortar (specifically water glass-based) to the joints. This will securely fix the asbestos clamps, effectively countering any sagging caused by thermal expansion.
Positioning Clearances
Heating zone taper: Ensure a clearance of 25-30 mm from the furnace walls for optimal efficiency.
Cold ends: These should extend at least 75 mm above the furnace roof to maintain proper function.
Lower heating end: It is recommended to keep a distance of ≥50 mm from the furnace floor to ensure safety and performance.
Spacing Between Rods
Make sure to ensure Our RJ New Corundum Furnace Tube Crucible showcases an innovative design with a center-to-center distance that exceeds standard rod spacing specifications, ensuring optimal performance.At HENAN RUNJING INSTRUMENT EQUIPMENT CO.,LTD, we meticulously engineer each product to the highest standards.
Advanced Gravity Balance System
Ingenious balance weight distribution is meticulously designed at both cold ends and critical wiring parts, effectively preventing any bending of the heating section, thereby extending product longevity and reliability.
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