| Customization: | Available |
|---|---|
| After-sales Service: | on-Line Service |
| Warranty: | 1 Years |
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Purpose:
Our esteemed Corundum Furnace Tube acts as the essential inner lining of a variety of experimental electric furnaces. Its primary role is to effectively isolate the delicate heating elements from test materials, securely enclose the heating zone, and hold the substances under examination. It finds extensive application in high-temperature testing and analytical instruments across a spectrum of industries including coal testing, metallurgical powder analysis, and the chemical and glass laboratory sectors.
Material & Manufacturing:
These premium corundum furnace tubes are expertly crafted from high-quality fused alumina, and are available in two distinguished types:
Ultra-fine powder-bonded
Clay-bonded
Our specifications are fully customizable to meet your specific demands, taking into account operating temperature, wear resistance, and resistance to chemical corrosion.
Dimensions:
Outer diameter: Ranging from 15 to 200 mm
Length: Spanning from 100 to 2000 mm
Wall thickness: Between 3 to 15 mm
Usage Guidelines:
When engaging with high-temperature testing equipment, it is crucial to ensure a gradual process of heating and cooling to effectively minimize internal stress caused by thermal expansion and contraction. This practice significantly lowers the risk of cracking and prolongs the tube's service life.
Composition:
Crafted from porous fused alumina, these crucibles boast exceptional durability and impressive heat resistance.
Applications:
Perfectly suited for melting samples in combination with weak alkaline fluxes such as anhydrous NaCO.
However, these are not suitable for use with strong alkaline fluxes like NaO, NaOH, or acidic fluxes such as KSO.
99.70% Corundum
Maximum short-term temperature tolerance: up to 1800°C
Exhibiting robust mechanical strength even in oxidizing or reducing atmospheres.
Known for its high thermal conductivity and minimal thermal expansion.
Operating range: Spanning 1650°C to 1700°C
Boasting excellent high-temperature insulation &
chemically inert properties to air, steam, H, CO, etc., up to 1700°C.
99.35% Corundum
Maximum short-term temperature tolerance: up to 1750°C
Operating range: Spanning 1600°C to 1650°C
Maintains stability even in oxidizing or reducing atmospheres.
85.00% High-Alumina
Maximum short-term temperature tolerance: up to 1400°C
Operating range: at 1290°C
Offers excellent insulation and mechanical strength in oxidizing or reducing atmospheres.
Features high thermal conductivity with minimal thermal expansion.
Inert to air, steam, H, CO, and more.
Ideal for extended use in environments with consistent temperature stability.
Quartz glass tubes are a high-performance industrial glass made primarily from silicon dioxide (SiO2). They serve as an outstanding foundational material, renowned for an array of exceptional physical and chemical properties, including:
Softening point: Approximately 1730°C
Adapted for sustained use at: 1100°C
Withstand short-term peaks up to: 1450°C
Virtually inert to most acids with the exception of (HF).
Acid resistance factor:
30 times that of ceramic materials
150 times that of stainless steel
Outstanding stability against high-temperature chemical reactions, surpassing other engineering materials.
Featuring an exceptionally low thermal expansion rate.
Capable of withstanding sudden temperature fluctuations (e.g., direct heating to 1100°C followed by rapid cooling in room-temperature water without cracking).
Offers excellent light penetration from UV to infrared wavelengths.
Visible light transmission rate: Exceeds 93%
UV light transmissibility: Reaching up to 80%+
Resistivity is: 10,000 times greater than that of typical glass.
Maintains excellent insulation properties even at elevated temperatures.
Applications & Characteristics
Suitable for applications up to 1450°C, available in both transparent and opaque versions.
Key Advantages: Extremely high purity, exceptional temperature endurance, sizeable dimensions with precise accuracy, superior thermal insulation, energy efficiency, and consistent quality.
Chemical Compatibility
Not resistant to hydrofluoric acid (HF) .
At elevated temperatures, it reacts readily with strong alkalis and alkali metal carbonates.
Ideal Fluxes
Perfect for sample melting using potassium pyrosulfate (KSO) or potassium bisulfate (KHSO).
Can also be utilized with sodium pyrosulfate (NaSO), pre-dried at 212°C for effective sample processing.
Quartz Crucible Usage & Maintenance: Master the art of leveraging quartz crucibles to their full potential. Learn best practices for maximizing performance while ensuring longevity in your applications. Proper usage and meticulous maintenance are key to unlocking the full capabilities of these essential instruments.
Primary Chemical Composition: At the heart of our quartz crucibles lies Silicon dioxide (SiO), a robust and reliable compound known for its exceptional stability and performance in demanding environments.
Chemically Inert: Quartz crucibles are renowned for their resistance to most acids, setting the standard for durability and reliability. However, exercise caution with hydrofluoric acid (HF), caustic alkalis, and alkali metal carbonates as they may induce reactions.
Thermal Stability Excellence: Experience unparalleled thermal stability with our quartz crucibles, a hallmark of our design that ensures consistent performance even under thermal stress.- Versatile Heating: Our quartz crucibles can be heated directly over an open flame, showcasing their adaptability and reliability in various heating scenarios.
Glass-Like Fragility: Handle with care, as these crucibles possess a fragility akin to fine glassware, demanding gentle and precise manipulation.- Delicate Handling Required: Our quartz crucibles require meticulous handling to prevent damage and ensure optimal performance.
Permissible Fluxes Insight::
Approved Fluxes: Utilize fluxes such as potassium bisulfate (KHSO) and sodium pyrosulfate (NaSO), pre-dried at 212°C, to extend the functionality and efficiency of your quartz crucibles.
Maximum Melting Temperature: Reach for the stars with a melting threshold of 800°C, enabling high-temperature applications with confidence.
Handling Precautions: Adhere to crucial handling guidelines to ensure the longevity and integrity of your quartz crucibles.
Brittle and Fragile: Recognize the delicate nature of these tools, crafted for precision and requiring considerate handling to avoid breakage.- Gentle Care Necessary: Prioritize careful handling techniques to preserve the structure and functionality of your crucibles.
Cleaning Excellence:
Effective Cleaning Agents: Discover reliable cleaning solutions for maintaining the pristine condition of your equipment. Dilute Inorganic Acids: Clean your quartz crucibles with ease using dilute inorganic acids, excluding HF, to maintain their integrity and cleanliness..
Material Characteristics Overview: Robust Characteristics: Experience the robust nature of our quartz crucibles, designed to resist thermal shock, maintain high-temperature integrity, and endure demanding conditions with unwavering performance. Key physical properties include:
Density: Appreciate the substantial density of 3.2 g/cm³, contributing to the durability and stability of our crucibles.
Mohs Hardness: With a Mohs hardness of 9.5, these crucibles are built to withstand rigorous conditions.
Specific Heat Capacity: The specific heat of 0.17 kcal/kg·°C ensures efficient thermal management.
Thermal Conductivity: Experience superior thermal conductivity at 20 kcal/m·h·°C, facilitating optimal heat distribution.
Linear Expansion Coefficient: The linear expansion coefficient is precisely measured at 5×10 (m/°C), indicating excellent thermal stability.
Exceptional Chemical Stability: Silicon carbide rods demonstrate remarkable chemical resilience, particularly against acidic substances, while remaining susceptible to alkaline attack at elevated temperatures.
High-Temperature Reactions: Operating Above 1000°C: When subjected to temperatures above 1000°C, silicon carbide rods engage in reactions with oxygen and water vapor, resulting in:Reactive Chemistry Reactions: Experience the dynamic interactions of silicon carbide with environmental elements.
SiC + 2O → SiO + CO: A chemical transformation that highlights the reactive nature of SiC under specific conditions.
SiC + 4HO → SiO + 4H + CO: A multifaceted reaction showcasing the complexity and transformative potential of silicon carbide.
SiO Content Increase: These reactions progressively elevate the SiO content within the rod, leading to heightened resistance and eventual aging.
Harmful Cycle Prevention: Mitigate the impact of excessive water vapor that accelerates SiC oxidation, initiating a cyclical reaction with detrimental effects on rod lifespan.
Nitrogen (N) as a Protective Agent: Anti-Oxidation Under 1200°C: Within certain temperature thresholds, nitrogen effectively inhibits SiC oxidation. Protective Threshold: Below 1200°C, nitrogen serves as a guardian against oxidation. Reacting Above 1350°C: However, above 1350°C, nitrogen engages in reactions that decompose SiC. Decomposition Threshold: When temperatures exceed 1350°C, nitrogen reacts to break down SiC., risking decomposition.
Chlorine (Cl) Effects: Complete Decomposition: Exposure to chlorine results in the total breakdown of silicon carbide, necessitating caution in its presence.
Understanding Fragility: Impact Sensitivity: Silicon carbide rods, known for their hardness and brittleness, must be shielded from strong impacts and vibrations during transit and handling to prevent damage.
Optimizing Heating Zone Length: Furnace Compatibility: Ensure the heating section aligns with the furnace chamber's dimensions, avoiding overextension that could harm the furnace wall.
Cold End Length Specifications: Precision Cold End Length: The cold end should be designed to match the furnace wall thickness, with an additional extension of 50-150 mm: Ensure optimal cooling and secure clamping with the specified extension range for enhanced performance and safety outside the furnace wall. to maintain cooling and secure clamping.
Furnace Hole Diameter: This should ideally be 1.4-1.6 times the cold end's outer diameter. Ensure no tight holes or obstructive fillers restrict thermal expansion, as this can cause breakage. Install rods with flexibility for 360° rotationto allow for optimal performance.
Spacing Requirements:
Maintain a minimum distance from heated materials or furnace walls of at least 3 times the heating zone diameter.
Ensure the center-to-center spacing between rods is no less than 4 times the heating zone diameter for efficient heat distribution.
Electrical Connection:Ensure secure connections to minimize contact resistance and the risk of cracking.
Resistance Matching: Before initiating use, categorize rods with similar resistance valuesto ensure consistent performance.
Connections: It is advisable to use aluminum braids or foil for connecting the cold ends to the main circuit. Ensure all clamps are securely tightened for optimal conductivity.
Furnace Preheating: Preheat new or long-idle furnaces using existing rods or alternative heat sources to ensure uniform temperature distribution.
Storage: Store rods in a dry environment, as moisture can compromise the cold end's aluminum layer.
Voltage Control: Utilize a voltage regulator to carefully control the voltage. Initiate at 50% of the operating voltage, gradually increasing to prevent thermal shock.
Operating Limits:
Optimize surface load and temperature to remain within safe operational parameters.
Maximum temperature: should not exceed 1650°C.Avoid exposure to corrosive gases to prevent adverse chemical reactions.
When exposed to corrosive gas environments, chemical reactions should be avoided.
Replacement: When replacing rods, ensure they have similar resistance or replace the entire set for uniform performance. Partially used rods can be repurposed if resistance aligns.
Avoid Molten Metal: Prevent any contact with molten metal to avoid rod breakage.
Avoid Alkalis: Keep away from alkali metals and oxides, which can corrode the rods.
Regular Checks: Consistently monitor amperage, voltage, and temperature. Inspect thoroughly for:
Loose or oxidized clamps,
any rod fractures,
and uneven heating, such as 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 the realm of high-temperature oxidizing atmospheres, our silicon molybdenum rods boast an impressive feature: they develop a protective quartz (SiO) layer that acts as a shield against further oxidation. This remarkable quartz layer, when exposed to temperatures beyond 1700°C, undergoes a transformation by melting. However, fear not, for even in continued use within oxidizing environments, the protective quartz layer demonstrates its resilience by regenerating, ensuring prolonged performance and efficiency.
Important Note: Silicon molybdenum rods are not suited for extended usage within the 400-700°C range due to the risk of low-temperature oxidation. Such conditions can lead to the element's deterioration, reducing it to a powdery form. For optimal longevity and performance, avoid operating within this temperature spectrum.
| 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 are known to exhibit slight softening when exposed to high temperatures (above 1500°C), while at lower temperatures, they become hard and brittle. To effectively mitigate thermal stress and accommodate the natural thermal expansion and contraction of these rods, a free-hanging vertical installation is highly recommended. This installation technique not only minimizes stress but also allows for the hot replacement of rods, eliminating the need to wait for the furnace to cool down, thus enhancing operational efficiency.
Furnace Lining Material
Use corundum bricks with FeO content <1%. It is crucial to note that higher FeO content can react with the protective SiO layer, resulting in the formation of low-melting silicates, which can accelerate the degradation of the rods.
Cold-End Sealing
Prevent hot gas leakage from cold ends as it can increase heat loss and potentially damage conductive clamps or leads. Asbestos clamps are recommended for effective insulation, ensuring the integrity of the installation.
Handling Fragility
Si-Mo rods are brittle and possess low flexural strength. It is imperative to handle them with care and avoid impacts during installation to prevent damage.
Secure asbestos/ceramic clamps with precision before connecting conductive straps to ensure a stable and secure connection. Do not overtightento prevent damaging the rod structure and maintain the integrity of the installation.
Mounting with Insulating Bricks
Use foamed corundum split bricks to safely house the rods, minimizing mechanical stress during both installation and removal, ensuring seamless operation.
Furnace Roof Installation
Insert rod-mounted bricks into precisely cut slots in the furnace roof for a secure fit. Extend bricks beyond the roof surface to facilitate easier disassembly and maintenance activities.
Conductive Strap Connection
Securely connect straps to the pre-installed brackets, ensuring stability. Avoid tension or unnatural bends to safeguard against stress that could compromise the system's integrity.
Anti-Sagging Measure
Apply refractory mortar (water glass-based) to joints, firmly securing asbestos clamps, effectively countering drooping caused by thermal expansion.
Positioning Clearances
Heating zone taper: Maintain 25-30 mm clearance from furnace walls to ensure optimal performance and safety.
Cold ends: Extend 75 mm above the furnace roof for effective ventilation and heat dissipation.
Lower heating end: Maintain a minimum clearance of ≥50 mm above the furnace floor to ensure optimal performance.
Spacing Between Rods
Guarantee that the center-to-center distance meets or exceeds the specified rod spacing requirementsfor efficient operation.
Gravity Balance
Ensure balanced weight distribution at both the cold ends and wiring components to effectively prevent any bending of the heating section, promoting durability and reliability.
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