Evaluation and validation of a fully instrumented Huttlin HKC 05-TJ laboratory-scale fluidized bed granulator

The instrumentation and validation of a laboratory-scale fluidized bed appa ratus is described. For continuous control of the process, the apparatus is instrumented with sensors for temperature, relative humidity (RH), and air velocity. Conditions of inlet air, fluidizing air, product, and exhaust ai r were determined. The temperature sensors were calibrated at temperatures of 0.0 degrees C and 99.9 degrees C. The calibration of the humidity sensor s covered the range from 12% RH to 98% RH using saturated electrolyte solut ions. The calibration of the anemometer took place in a wind tunnel at defi ned air velocities. The calibrations led to satisfying results concerning s ensitivity and precision. To evaluate the reproducibility of the process, 1 5 granules were prepared under identical conditions. The influence of the t ype of pump used for delivering the granulating liquid was investigated. Pa rticle size distribution, bulk density, and tapped density were determined. Granules Mere tableted on a rotary press at four different compression for ce levels, followed by determination of tablet properties such as weight, c rushing strength, and disintegration time. The apparatus was found to produ ce granules with good reproducibility concerning the granule and tablet pro perties.