Regular readers of Process Heating understand that each of the myriad dryer designs can effectively remove moisture from a range of materials. But, each type of dryer also comes with capabilities and characteristics that offer either advantages or disadvantages based on the materials to be processed and requirements of each application.

Process heating equipment skids include standard unitary steel bases that allow cover-lift hoists, process air ductwork, control panels, monitoring instrumentation and other auxiliary equipment to be attached to the system as a single unit.

Claiming that a dryer can dry or dehydrate almost any solid may seem like a bold and sweeping statement. Yet, it is true.

Fluid-bed dryers offer an inherently efficient method of moisture removal that has not changed since the systems were developed in the 1950s. The introduction of ever-improving control technologies — personal computer-based and PLC control systems, smart sensors and other technological advances — in the last 40 years, however, has changed how process engineers operate their fluid-bed drying systems.

It’s a point of pride that I have every issue of Process Heating ever published cataloged in a small library in my home office. Admittedly, it’s not as tidy as you might find at your local library. I tend to stack issues that I “check out” on the floor in front of the library until it’s time to clean my office. And, while my lazy filing means a career as a bibliophilic cataloger is doubtful, it also provides opportunities for rediscovery.

Designed to recycle nitrogen to increase the amount of nitrogen in the process air to 85 percent to render combustion impossible, the fluid-bed drying system has an integral baghouse dust collector set directly above the fluid-bed drying zone to create a sealed system. 

Drying system includes an integral baghouse dust collector positioned directly above the fluid bed drying zone. The configuration is designed to contain all of the fine particles entrained in the airstream and allow them to remain in the dryer for processing as product rather than collecting them remotely or accepting their loss as waste. 

A manufacturer of vibratory fluid bed dryers, coolers, classifiers, screeners and other machinery, Witte Co., Washington, N.J., is celebrating its 80th anniversary.

A pneumatic cover lift that automatically raises the dryer cover at the push of a button allows a single operator to open the fluid-bed dryer or cooler to clean or inspect the system.

It is no coincidence that the energy-cost-reducing technology used to recover and reuse heated process air in fluid-bed drying systems was developed during the energy crisis of the 1970s.