A moderate temperature in all seasons

New sugar dryer from BMA America for North Dakota

The American Crystal Sugar Company is welcoming a new drum dryer and cooler. This will help operators at the Drayton sugar factory in North Dakota solve one problem: the large ­differences in temperature between the seasons.

The old and outdated drying equipment was not performing consistently under all production and ambient conditions. The vertical sugar cooler equipped with plate packs experienced problems with high sugar temperatures especially during the summer months.

Same temperatures, better performance

Because the existing cooler will continue to be used in the new system, American Crystal Sugar needs a design that will produce consistently free-flowing sugar with constant temperature and moisture levels. With the new dryer, it should also be possible to increase the factory’s processing capacity in the future.

The plant is designed to dry sugar at a rate of 76 t/hr to a moisture content of 0.03 %. It should also pre-cool the sugar from 68 to 55 °C all year round, but especially in summer and in winter. During the warm months, temperatures at the location can soar up to 32 °C – and drop to as low as minus 30 °C in the cold season.

One plant section for drying, one for cooling

The drum has a drying section and a cooling section. While the drying air enters through a central pipe, the pre-cooling air enters through the outlet plenum, countercurrent to the sugar flow. The conditioning system for the drying and pre-cooling air consists of several heat exchangers, dehumidifiers and filters. These provide constant parameters in all weather conditions.

Hans-Joachim Schmidt