IPDB › China Industry › Instruments & Meters

China, Chinese High-Quality Molybdenum Disilicide Heating Elements by Rj - New Condition¹ Industrial Products Supplier Manufacturer Details, price list catalog:

China Industrial Products Supplier Manufacturer List Catalog

Heating Refrigeration Temperature Control Heating Element Heating Elements High-Performance Heating Elements

HENAN RUNJING INSTRUMENT EQUIPMENT CO.,LTD

Preview:

Product Description Corundum Furnace TubePurpose:The corundum furnace tube is an essential component serving as the protective inner lining in a range of experimental electric furnaces. It primarily functions to isolate sensitive heating elements from test materials, creating a secure enclosure for the heating zone while supporting and containing the test substances. This robust tube is a staple in high-temperature testing and analytical instruments, with widespread applications across industries, including coal testing, metallurgical powder analysis, and in chemical and glass laboratory settings.Material & Manufacturing:Crafted with precision, corundum furnace tubes are predominantly constructed from fused alumina and are available in two specialized types to meet diverse needs:Ultra-fine powder-bondedClay-bondedSpecifications are meticulously tailored to user-specific requirements, taking into account factors such as operating temperature, wear resistance, and resilience to chemical corrosion.Dimensions:Outer diameter: Ranges from 15 mm to a substantial 200 mmLength: Extends from a compact 100 mm to a lengthy 2000 mmWall thickness: Precision thickness available between 3 mm and 15 mmUsage Guidelines:To ensure optimal performance of high-temperature testing equipment, it is crucial to implement gradual heating and cooling processes to effectively mitigate internal stress caused by thermal expansion and contraction. This practice significantly reduces the risk of cracking, thereby enhancing the service life of the tube.Corundum CrucibleComposition:Expertly fashioned from porous fused alumina, offering unmatched durability and heat resistance.Applications:Ideal for melting samples in the presence of weak alkaline fluxes (such as anhydrous NaCO).Not suitable for use with strong alkaline fluxes (e.g., NaO, NaOH) or acidic fluxes (e.g., KSO).Product Performance:99.70% CorundumMaximum short-term temperature capacity reaching: 1800°CExemplary mechanical strength in both oxidizing and reducing atmospheres.Features high thermal conductivity paired with low thermal expansion.Operating range: 1650-1700°CDelivers exceptional high-temperature insulation andremains chemically inert when exposed to air, steam, hydrogen, carbon monoxide, and more, up to 1700°C.99.35% CorundumMaximum short-term temperature capacity reaching: 1750°COperating range: 1600-1650°CMaintains stability in both oxidizing and reducing atmospheres.85.00% High-AluminaMaximum short-term temperature capacity reaching: 1400°COperating range: 1290°CExhibits admirable insulation and mechanical strength in both oxidizing and reducing atmospheres.Boasts high thermal conductivity with minimal thermal expansion.Chemically inert to air, steam, hydrogen, carbon monoxide, and similar environments.Suitable for Designed for long-term use, ensuring ongoing reliability and performance. Optimally functions under stable temperature conditions, providing consistent results.Quartz Glass TubeQuartz glass tubes are a highly specialized form of industrial glass, crafted from silicon dioxide (SiO). They are renowned for their exceptional physical and chemical properties, which include:High-Temperature ResistanceImpressive softening point of approximately 1730°C.Long-term operational use at temperatures reaching up to 1100°C, ensuring durability and resilience.Capable of withstanding short-term maximum temperatures of: 1450°C, demonstrating its robustness.Corrosion ResistanceExhibiting near-inertness to all acids, with the exception of hydrofluoric acid (HF),making it highly resistant.The acid resistance is:30 times greater than that of ceramics,and 150 times greater compared to stainless steel, offering superior performance.Unparalleled high-temperature chemical stabilitythat surpasses other engineering materials.Thermal StabilityCharacterized by an extremely low thermal expansion coefficient,it robustly withstands rapid temperature fluctuations such as immediate heating to 1100°C followed by quenching in room-temperature water, without cracking.Optical TransparencyDelivers excellent light transmission across the UV to infrared spectra.This includes a visible light transmittance of:Over 93%, ensuring clarity and visibility.UV spectrum transmittance can reach: up to 80% or more, enhancing utility in various applications.Electrical InsulationBoasts a resistivity that is 10,000 times higher than ordinary glass, maintaining excellent insulation properties even at elevated temperatures.Ensures superb insulation capabilities under high thermal conditions.Quartz CrucibleUsage & PropertiesEngineered for use at temperatures up to 1450°C, available in bothtransparent and opaque forms to suit diverse needs. variants, tailored for specific applications.Advantages: Features high purity, outstanding temperature resistance, large size with precision, excellent thermal insulation, energy efficiency, and stable quality,making it a preferred choice.Chemical CompatibilityIncompatible with hydrofluoric acid (HF), ensuring safety in various chemical processes.At elevated temperatures, it may react with caustic alkalis and alkali metal carbonates,necessitating careful handling.Suitable FluxesPerfect for melting samples with compounds like KSO (potassium pyrosulfate) or KHSO (potassium bisulfate),ensuring process efficiency.Additionally, it can be used with NaSO (sodium pyrosulfate, pre-dried at 212°C) for effective sample processing.Quartz Crucible Usage & MaintenancePrimary Chemical Composition: Our advanced molybdenum disilicide heating elements are enriched with high-purity Silicon Dioxide (SiO), showcasing unparalleled efficiency.Chemical Resistance: These elements are virtually impervious to most acids (except the formidable HF). However, they exhibit a reactivity with caustic alkalis and alkali metal carbonates, ensuring optimal operational integrity.Thermal Stability: Revel in the exceptional thermal stability that defines these heating elements, offering peak performance even under fluctuating thermal conditions.Direct Heating Capacity: Our heating elements can be effortlessly heated directly over a flame, simplifying processes and enhancing versatility.Glass-like Fragility: Although resilient in many ways, these elements possess a delicate fragility akin to glassware, necessitating cautious handling.Handling Necessities: Given their fragile nature, these elements demand meticulous handling to prevent accidental damage.Permissible Fluxes: Explore a diverse range of permissible fluxes that can be utilized in conjunction with these elements.:Flux Examples: Potassium bisulfate (KHSO) and sodium pyrosulfate (NaSO), pre-dried at a controlled 212°C, represent just a fraction of the compatible options.Melting Potential: These elements boast an impressive maximum melting temperature of 800°C, ensuring robust performance across applications.Handling Precautions: Essential guidelines to preserve the integrity and longevity of these delicate heating elements.Brittleness: Despite their durability, these elements are brittle and fragile, emphasizing the need for gentle handling.Careful Handling: Adopt a gentle approach to handling to prevent any breakage or compromise of these premium elements.Cleaning Instructions: Keep your heating elements pristine with our recommended cleaning procedures.Cleaning Agents: Suitable cleaning can be achieved using dilute inorganic acids, barring HF, ensuring safe and effective maintenance..Material Characteristics: Discover the unique material properties that define our heating elements, crafted for superior performance. Physical Excellence: Hard yet brittle, these elements are resistant to thermal shock and remain stable at high temperatures, offering consistency you can rely on.Density: With a density of 3.2 g/cm3, our elements stand as a testament to the balance of strength and subtlety.Mohs Hardness: Boasting an impressive Mohs Hardness of 9.5, they exhibit remarkable resistance to wear and tear.Specific Heat: A specific heat of 0.17 kcal/kg·°C highlights their efficient thermal performance.Thermal Conductivity: With a thermal conductivity of 20 kcal/m·h·°C, these elements ensure uniform heat distribution.Expansion Coefficient: The linear expansion coefficient is precisely 5×10 (m/°C), underpinning their reliable structural integrity.Chemical Properties: The robust chemical properties of silicon carbide rods reinforce their suitability for demanding environments.Chemical Stability: Exhibiting exceptional chemical stability, they resist acids with ease but require caution against alkaline substances at elevated temperatures.Temperature Reactions: Beyond 1000°C, these rods interact with oxygen and water vapor, resulting in:Oxidative Reactions: SiC + 2O → SiO + CO, highlighting ongoing transformations at heightened temperatures.Water Vapor Interaction: SiC + 4HO → SiO + 4H + CO, illustrating the complexity of chemical reactions under heat.Aging Process: Such reactions incrementally elevate SiO levels, potentially increasing resistance and accelerating aging.Vapor Impact: Excessive water vapor can expedite oxidation, and the ensuing H reacts with O, perpetuating a cycle that diminishes rod lifespan.Element Interaction: Nitrogen (N) counters oxidation of SiC below 1200°C, but poses a risk above 1350°C, where it may lead to decomposition.Chlorine Influence: Chlorine (Cl) poses a significant threat by completely decomposing SiC, necessitating caution.Usage Precautions: Adhere to these guidelines to optimize safety and performance.Fragility Alert: The inherent hardness and brittleness of silicon carbide rods necessitate protection from impacts or vibrations during transit and handling. Transport and Handling: Ensure gentle handling to maintain the integrity of these robust yet delicate components.Heating Zone Precision: Ensure the heating section aligns with the furnace chamber's dimensions, as overextension can damage the furnace wall. Furnace Compatibility: Proper alignment within the furnace chamber is crucial for longevity and efficiency.Cold End Configuration: The cold end should integrate the furnace wall thickness with 50-150 mm additional extension for optimal cooling and secure clamping. Extension Allowance: Ensure the cold end's extension is sufficient for effective operation.Structural Specifications: Furnace Hole Diameter: Ideal diameters ensure secure and efficient placement of the rods. Ensure Optimal Fit: Proper diameter selection is critical for performance and longevity. 1.4-1.6× The cold end's outer diameter is pivotal for robust performance. Ensure tight holes or appropriate filler materials are used to accommodate expansion. This prevents breakage by allowing thermal expansion, thus enhancing longevity. Install rods designed to permit. 360° rotation.Spacing Requirements:Maintain the distance from the heated materials or furnace wall at ≥ 3× the diameter of the heating zone.Ensure the center-to-center spacing between rods is no less than ≥ 4× the heating zone diameter.Electrical Connections are crucial, as they can increase contact resistance and elevate the risk of cracking.Resistance Matching: Before the initial use, meticulously group rods with similar resistance valuesto ensure uniform performance and optimal efficiency.ns: Utilize aluminum braids or foil for connecting cold ends to the main circuit. Ensure that clamps are securely tightened for stable operation.Furnace Preheating: Preheat newly installed or long-idle furnaces using previously used rods or alternative heat sources to prevent thermal stress.Storage: Store rods in a dry environment. Moisture can degrade the aluminum layer on the cold end, compromising functionality.Voltage Control: Employ a voltage regulator. Start at 50% of the operating voltage, gradually increasing it to prevent thermal shock and ensure safe startup.Operating Limits:Surface load and temperature must be carefully optimized for peak performance.Max temperature: ≤1650°Cfor sustained efficiency and safety.Avoid chemical reactions in environments with corrosive gases to maintain structural integrity.Replacement: Replace rods with those of similar resistance values, or consider replacing the entire set for uniformity. Partially used rods can be reused if their resistance is still suitable, ensuring continued performance.Avoid Molten Metal: Prevent contact with molten metal, as it can lead to breakage and damage.Avoid Alkalis: Alkali metals and oxides can corrode the rods, reducing their lifespan.Regular Checks: Consistently monitor amperage, voltage, and temperature. Conduct inspections for:Loose or oxidized clamps,Rod fractures,Uneven heating indicated by red-hot zones.Main Applications:Silicon molybdenum (Si-Mo) heating elements are integral to metallurgy, steelmaking, glass, ceramics, refractory materials, crystal growth, electronic components, and semiconductor material research and manufacturing. They are particularly indispensable in crafting high-performance precision ceramics, advanced synthetic crystals, precision structural cermets, fiberglass, optical fibers, and high-grade alloy steels.PropertyValueBulk Density5.5 g/cm3Flexural Strength15-25 kg/cm2Vickers Hardness(HV) 570 kg/mm2Porosity7.4%Water Absorption1.2%Thermal Elongation4%Chemical Properties of Silicon Molybdenum RodsIn high-temperature oxidizing atmospheres, silicon molybdenum rods develop a protective quartz (SiO) surface layer that effectively prevents further oxidation. When the element temperature surpasses 1700°C, this quartz layer melts. If continued use persists in oxidizing atmospheres, the protective quartz layer regenerates, maintaining the rod's integrity.Important Note: For long-lasting performance, avoid using silicon molybdenum rods within the 400-700°C range. Prolonged exposure within this temperature band can lead to detrimental low-temperature oxidation, gradually turning the element into powder form, hence shortening its lifespan.Maximum Operating Temperatures in Various Atmospheric ConditionsAtmosphereContinuous Use Temp.Short-term Max Temp.NO, CO, O, Air1700°C1800°CHe, Ar, Ne1650°C1750°CSO1600°C1700°CCO, N1500°C1600°CMoist H1400°C1500°CDry H1350°C1450°CEssential Installation Precautions for Silicon Molybdenum RodsSilicon molybdenum (Si-Mo) rods tend to soften slightly when exposed to high temperatures exceeding 1500°C. Conversely, they become hard and brittle at lower temperatures. To effectively manage thermal stress and accommodate thermal expansion and contraction, a free-hanging vertical installation is highly recommended. This setup not only optimizes performance but also allows for hot replacement of rods without waiting for the furnace to cool down, thereby enhancing operational efficiency.Key Installation Guidelines to Follow:Furnace Lining Material SelectionUse corundum bricks that contain less than 1% FeO. A higher FeO content can react adversely with the protective SiO layer, leading to the formation of low-melting-point silicates that expedite rod degradation.Cold-End Sealing ConsiderationsPrevent hot gas leakage from cold ends to minimize heat loss and avoid damage to conductive clamps or leads. Opt for asbestos clamps to ensure superior insulation.Managing the FragilitySi-Mo rods are inherently brittle and possess low flexural strength. Handle them with care to avoid impacts during installation.Secure asbestos or ceramic clamps firmly before attaching conductive straps to support the system's reliability. Take care not to overtightenthese connections.Mounting Method with Insulating BricksUse foamed corundum split bricks for housing rods, which helps in minimizing mechanical stress during the installation or removal process.Installing in the Furnace RoofInsert rod-mounted bricks seamlessly into pre-cut slots in the furnace roof. Allow bricks to extend beyond the roof surface to facilitate easier disassembly and maintenance.Connecting Conductive StrapsAttach straps securely to pre-installed brackets, ensuring a reliable connection. Avoid placing straps under tension or creating unnatural bends as this may induce stress leading to potential failures.Anti-Sagging MeasuresUtilize refractory mortar with a water glass base for joint application, securing asbestos clamps firmly to counteract sagging induced by thermal expansion.Positioning and Clearance GuidelinesIn the heating zone taper: Maintain a clearance of 25-30 mm from furnace walls to ensure safe operation.At the cold ends: Ensure an extension of 75 mm above the furnace roof for optimal safety.For the lower heating end: Maintain a distance of at least50 mm from the furnace floor to prevent overheating.Spacing Between RodsEnsure proper spacing is maintained Ensure the center-to-center distance is equal to or greater than the specified rod spacing for optimal performance..Achieve superior stability with our advanced Gravity Balance technology.Strategically distribute balance weight at both the cold ends and wiring parts to effectively prevent any bending of the heating section, ensuring longevity and efficiency.

× More Keyword ..

× More Menu ..

×

Manufacturing & Processing Machinery

×

Industrial Equipment & Components

×

Tools & Hardware Products