In October 2013, American Crystal Sugar commissioned BMA America to supply a new sugar drying and cooling system, which is to help cut energy costs and optimize the cooling process.
Energy-efficient drying and cooling
The American Crystal Sugar Company was looking for energy improvement options for their factories and identified the sugar drying and cooling system in its East Grand Forks, North Dakota factory as a prime candidate. In the existing system, two smaller rotary drums operate as granulator and cooler in series. The new system will consist of a rotary drum dryer and a horizontal fluidized bed cooler. It is designed to dry and cool 40,000 cwt/ day sugar (or about 75 t/h) from 68 to 30 °C in the winter time as well as in the summer time.
High sugar temperatures especially in summer have been a challenge in the past. The new horizontal fluidized bed with its built in cooling coils
which provide very efficient heat transfer will enable the factory to produce cold sugar even under hot summer conditions. The cooling coils are connected to a closed loop water recirculation system which incorporates a chiller. The secondary loop of the chiller is connected to an outside heat exchanger. This loop is filled with a water glycol mix because outside temperatures in North Dakota can frequently reach -30 °C in winter.
The temperature of the fluidization air of the sugar cooler which also serves in part as cooling air will be increased by the hot sugar before leaving the cooler. This exhaust air is fed countercurrent to the drum dryer to use its energy content and further minimize the energy consumption of the system.
Excellent collaboration within the BMA Group
This project is a good example of how BMA America operates. The goal is to provide these projects to our customers through BMA America from sales to engineering to fabrication to com- missioning and service. Key components and knowledge will be sourced from BMA Germany as needed. The entire sales process for this project was handled by BMA America. Process and technology support was provided by BMA Germany. The engineering tasks were split between BMA America and BMA Germany, while the project management was provided by BMA America.
Especially the fabrication is a nice example of BMA‘s teamwork within the group of companies. BMA Germany provided the design and drawings. Some core components like the drum tires and the roller frames were supplied by BMA Germany to BMA America in Greeley. There they became an integrated part of the drum dryer fabrication. The fluidized bed cooler was manufactured at BMA America and the cooling coils were manufactured at BMA in Germany.
Hans Schmidt
BMA America
hans.schmidt@bma-us.com