摘要 |
A modular air fluidized sand bed for the heat treatment of metal products is disclosed. This technology provides for the heat-treatment of steels, particularly long products, and other alloys and shapes using fluidized-sand heat transfer media. The technology directs gas burners into U-tube assemblies suspended in the media. The fluidizing agent is hot exhaust gas recovered from the U-tubes. Blended exhaust gases and cool air can maintain fluidizing gas, plenum and retort temperatures at nearly the same temperature as the sand. Constant volume and pressure of fluidizing gas maximizes heat transfer between sand and product. For extreme heating applications, a thermally insulated cover held in direct contact with the hot fluidized sand improves energy efficiency. A sand return system returns sand lost from the bed exit to entrance. The modular air fluidized sand bed includes a fluidization pressure and volume that are altered independent of a fluidization media temperature.
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