Drying Systems Can Handle Any Process Condition
Industrial drying system designs include rotary dryers, calciners, screw presses, multidisc thermal processors, flash dryers and fluid bed dryers. What they all have in common is they are used to remove excess moisture from the product being processed. Available heat sources range from hot fluids and steam to gas and electric. In this photo gallery, the advantages and disadvantages of some dryer designs are explored.
Related: What To Know When Selecting Dryer Equipment
Fluid Bed Dryers
Fluid bed dryers process granular, free-flowing material at product temperatures ranging from 140 to 300°F. Suitable materials include minerals, clays, organic salts, coal and specialty chemicals.
Multiple Disc Dryer
An indirect multiple disc dryer consists of a horizontal trough-shaped vessel, containing two or more rotating shafts mounted with discs. The large-surface-area discs are heated. As the shafts rotate, the discs contact and transfer heat to the material while gently dragging rather than pushing it through the vessel.
Types of Rotary Dryers
One of the most important factors in determining what type of rotary dryer is right for a certain process is the use of direct or indirect heat. Rotary dryers are capable of utilizing either direct convection-style heat transfer or indirect heat transfer, in which hot surfaces within the dryer provide heat by conduction and radiation. The determination of direct or indirect drying is contingent on the properties of the material to be dried, the process conditions and the desired end product.
Inside a Rotary Dryer
A material's physical or handling characteristics will eliminate some dryers. A steam-tube rotary dryer is not a good choice for a wet, sticky material such as mica. The dryer moves material by rotating and rolling it, and such passive conveying can't move a sticky material out of the inlet area before it cakes on the vessel wall and steam tubes.
Rotary Dryer on Barge
For continuous drying of bulk solids, rotary dryer excel in their ability to handle a broad range of materials regardless of their conveying and handling characteristics. Whether a process requires the drying of fine dusty powders, lumpy solids, sticky semi-plastics, pellets, agglomerates or even a mixture of all of those, there is a rotary dryer that will accomplish the task successfully.
Testing Laboratories
A pilot plant testing laboratory can be employed to determine the best technology and equipment for a customer's operations.