Synthetic drugs

Filtration experts, over the years, have discussed and debated filter presses and have indicated that soon they would be a thing of the past; the last filter press would be replaced by more modern equipment. Given that filter presses were amongst the oldest mechanical dewatering devices, this was a fairly plausible suggestion. However, now, almost half a century later, any chemical engineering exhibition shows that filter presses are alive and well and are going to be around for years to come. True, they look different from the ones in the 1950’s, but essentially they are still the same device. Their continued presence is a tribute to the filter press manufacturers who embraced new materials and upgraded the mechanics and configurations. However, the basics are still the same and much of the issues surrounding filter presses remain valid.

This article discusses the use of thin-cake vertical candle filters and horizontal pressure plate filters as alternatives to manual and conventional filter equipment. These new technologies are described as well as the selection process. The article includes test data and case histories and concludes with a discussion of clean-in-place operations and current Good Manufacturing Practices (cGMP) guidelines. ANSI/ISA S88 (and IEC 61512-1 in the international arena) batch process control system standards are also examined for validation. Finally, factory and site acceptance testing is described.

The BHS technologies of Vertical Candle Filters and Horizontal Pressure Plate Filters provide improved product quality with more efficient operations compared with manual pressure filters. The different technologies allow for the selection of the optimum process solution depending upon the cake characteristics and cake structure. Fully automatic operations provide for complete containment of the solids and liquids for reduced maintenance costs and overall project savings.