Industrial Dryers


Fluid Bed Dryers - Rotary Dryers
All Swenson Chemical Processing Equipment

The Swenson line of drying equipment has been manufactured since the chemical engineering pioneer Magnus Swenson founded the company in 1889. Swenson’s extensive line of drying equipment allows our engineers to select the optimal solution for a wide variety of drying problems.

Product Testing

Swenson Test Center

Swenson long ago recognized the customer’s need for product testing. The information available through testing is crucial to the success of the ultimate full-scale production application.Using firsthand dryer test results obtained in the Swenson Test Center, our engineers can assist customers in making knowledgeable decisions about drying techniques and recommend the appropriate, full-scale production equipment. The test center, located in Harvey, Illinois, is a completely equipped laboratory able to pretest, in either production or pilot operations, virtually any product.

Drying Process

Fluid Bed Dryer

When optimum heat transfer efficiency is required for the drying process, the Swenson fluid bed dryer is the best choice. The drying system features a stationary, upright shell, through which heated air is forced and/or induced by a blower arrangement.

Material enters the system through a feed chute or screw feeder, and is fluidized by the heated gas stream. This produces a high degree of intermixing and intimate contact of the material and the drying media, resulting in optimum heat transfer efficiency.

The hot gases used for drying can be generated by either steam coils or a combustion furnace. These gases enter the plenum chamber and are evenly distributed across the body of the dryer by a perforated plate. The holes in this plate are covered with caps which prevent material from entering the plenum when the dryer is not in operation. The vent gases are exhausted through a dust collector for maximum recovery of fines.

The dry product overflows an adjustable weir plate and is discharged continuously through a rotary air lock. The fluid bed dryer can be operated in either open or closed cycles.

The Fluid Bed Dryer could be operated in a closed cycle with the addition of a solvent recovery system and the use of an inert gas, such as nitrogen, as the drying medium.  Vent gases leaving the fluid bed dryer are cleaned by a cyclone or fabric collector, and a condenser to remove the solvent. The cooled, saturated gases are reheated in an indirect-fired air heater or steam coils, prior to entering the dryer.

Rotary Dryer

Parallel current operation exposes the wettest material to the hottest air, thus enabling heat-sensitive or sticky material to be dried successfully. The evaporation of water prevents the material from overheating. As the material becomes drier, the air becomes cooler. The hot air at the feed end of the dryer warms the shell and flights, helping to prevent sticking of wet or tacking material to the metal.

Counter-current operation exposes the driest material to the hottest air, thereby producing a product having a very low moisture content, without sacrificing thermal efficiency.

Rotary Dryer

Warm air dryers utilize steam coils to heat ambient air to temperatures as high as 350°F. An exhaust fan, located on either the clean side of a dry dust collector or before a wet scrubber, is used to induce the flow of air though the steam coils, dryer, and pollution control equipment.

Direct heat dryers use an oil, gas or dual-fuel burner housed in a combustion furnace to produce hot air, reaching temperatures of up to 1800°F. The air is drawn through the dryer and pollution control equipment by an exhaust fan.

Rotary coolers, using either ambient or refrigerated air as the cooling medium, are designed much like the rotary dryer and operate in the counter-current mode.

Contact Olivier Butete at for more information. 

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