Equipment

CALCINATION / HEAT TREATMENT

Multiple Hearth Furnace click to enlarge

HANKIN MULTIPLE HEARTH CALCINERS
Calcining, or heat soaking, alters the crystal structure of minerals, producing new, value-added characteristics to the mineral, such as high brightness with low abrasion. Normal temperatures range from 1500°-2100°F for periods of up to 60-minutes. This calls for a furnace capable of reliable, efficient and continuous operation for tens of thousands of hours. The Hankin multiple-hearth calciner is a vertical furnace comprised of alternating in and out hearths. The number of hearths is determined by the desired product rate, the process requirements (for time and temperature), and any pre- or post- temperature conditioning. Material is moved through the calciner by rabble teeth, or plows, driven from a central (vertical) shaft. Top feed, bottom outlet.

• Reliable process rate, product characteristics and efficiency predicted from laboratory evaluation.
• Stationary refractory for maximum thermal insulation and long life with low maintenance.
• Good turn-down ratio and flexibility.
• Accurate control of product residence time.
• Low dust carry-over.
• Minimum operator attention, suitable for automation.
• Small space requirement.
• Burners can be mounted on individual hearths with up to 4 burners per hearth.
• Burner mountings eliminate direct flame impingement on product.
• Burner management provides safe, precise and efficient combustion with accurate control of temperatures and atmosphere.
• Efficient heat transfer produces low heat input per ton of product.
• Feed preparation and product systems can be designed and provided.
• Many installations for various applications providing extensive experience.

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