Views: 7 Author: Site Editor Publish Time: 2025-07-05 Origin: Site
Metal powder refers to a collection of metal particles with a particle size smaller than 1 millimeter, encompassing single metal powders, alloy powders, and certain refractory compound powders with metallic properties. It serves as the primary raw material for powder metallurgy.The drying process of metal powder is critical to its quality and application performance, particularly in preventing oxidation, moisture absorption,etc.
Metal powders are highly sensitive to drying conditions, presenting the following technical challenges:
Metal powders are prone to oxidation, and conventional drying methods often result in the formation of an oxide layer on the surface, compromising material performance.
Different metal powders have significantly varied melting points. For instance, aluminum powder tends to agglomerate above 150°C, while tungsten powder requires heating above 300°C for effective drying.
Heavy metal powders tend to settle in traditional equipment, leading to uneven drying. This can result in a clumping rate of 10%-20%, severely impacting product quality. For example, single-cone ribbon vacuum dryers often struggle to stir heavy materials, causing uneven heating and reduced drying efficiency.
Traditional metal powder drying primarily relies on hot air convection drying, which has the following drawbacks:
Hot air drying requires 2000-3000 kcal of heat (approximately 8.4-12.6 MJ/kg) to evaporate 1 kg of water, resulting in high overall energy consumption, typically 800-1200 kWh per ton of material.
The recovery rate is only 60%-70%, leading to significant resource waste.
Post-drying oxygen content is often high (0.5%-1%), and the powder surface is prone to oxidation or contamination, adversely affecting subsequent processing.
For large-scale production, such as with spray dryers, the required spray tower size is substantial, increasing equipment investment costs by 30%-50%, making it unsuitable for large-scale production of certain alloy powders.
Our Hollow Screw Vacuum Dryer is optimized for the characteristics of metal powders, offering the following significant advantages:
Evaporating 1 kg of water requires only 1 kg of steam or 600 kcal of heat (approximately 2.5 MJ/kg), reducing energy consumption to 20%-30% of hot air drying. Energy consumption per ton of material is reduced to 150-250 kWh, saving 70%-80% compared to hot air drying.
The unique hollow screw blade structure increases the drying surface, boosting drying efficiency by 3-5 times compared to traditional equipment (based on actual test data).
The largest batch model has a capacity of 5000L, with dimensions of only 6m (L) × 2.1m (W) × 4m (H), significantly reducing plant construction and investment costs.
Continuous stirring by screw blades ensures cyclic movement of materials within the heating chamber, achieving more uniform heating and significantly reducing the risk of clumping.
Whether the raw material is liquid, powder, granules, or slurry, our dryer can process it into powder.
To address the issue of fine metal powders clogging filter bags, the dryer is equipped with a nitrogen pulse backflush system, ensuring continuous and stable operation.
Post-drying, powders are prone to moisture absorption due to high temperatures. The dryer’s cooling system, rapidly lowers the powder temperature to below 50°C, reducing moisture absorption to below 0.1%, ensuring storage stability.
Continuous drying is supported under vacuum conditions, allowing simultaneous feeding, drying, cooling, and discharging, significantly increasing production capacity.
If you are interested, welcome to contact us: info@machtechdryer.com , we have laboratory-scale dryers available for drying experiments.
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