| Dimitrios Zarkadas New Jersey Institute of Technology 
By adopting the bore of polymeric hollow fine fibers having a solid wall as the environment in which cooling crystallization occurs
in the solution flowing through the hollow fiber opening, Mr. Zarkadas overcame the traditional shortcomings of batch stirred cooling
crystallizers. The temperature difference between the inside wall and the crystallizing solution temperature could be kept as low as
1 to 2 degrees Centigrade compared with a 5 to 10 degree Centigrade difference in traditional crystallizers. Thus, supersaturation
creation at each hollow fiber cross section was relatively uniform. Flow conditions could be easily controlled; thus residence time
could be managed with great accuracy. Scale-up problems are eliminated since every hollow fiber operates as a separate and essentially
identical crystallizer. He showed the utility of this by the cooling crystallization of potassium nitrate from an aqueous solution,
among other methods.
To facilitate better temperature control in the Solid Hollow Fiber Cooling crystallizers (SHFC), he developed an effective model of heat transfer in the solid-wall hollow fiber device, studied heat transfer in this type of heat exchanger and showed how useful it can be in pharmaceutical processing environments for crystallization and heat exchange. These polymeric heat exchangers are an order of magnitude smaller, four times lighter and an environmentally benign substitute for the conventional bulky and costly metallic heat exchangers. |
