Steris takes WFI another step further
The latest addition to the STERIS Finn-Acqua range of stills for producing water for injection (WFI) incorporates a number of technological advances that enable it to offer improved performance, energy efficiency and dependability. The T-Series Multiple-Effect Water Still combines Finn-Aqua falling film evaporation technology with a new patented column construction and an enhanced process and design.
New features include the blow-down removal from each column, which enhances the quality of the WFI produced; a new condenser design; distillaton against backpressure in WFI tanks; recirculation of non-evaporated feed water; and continuous blow-down measurement. Meanwhile, advanced control systems with a choice between the latest PLCs from Siemens and Allen-Bradley offer streamlined control functions and improved interface with other process systems.
At the heart of the T-Series Multiple-Effect Water Still is the separator column à a new compact design falling film evaporator that removes impurities at high velocities. The compact column design means that the overall height of the equipment has been reduced.
Preheated feedwater enters the top of the separator column where it is atomised by means of a spraying system. The separated non-condensable gases are simultaneously released through a gas outlet port. The feedwater is dispersed into tubes inside the column and, using a falling film effect, is vaporised using plant steam as the heat source. The velocity of the steam increases as it reaches the bottom of the column, where it is forced to make a 180o turn. Non-evaporated feedwater is directed into the next column where it is forced upwards through spiral guides. The centrifugal force separates pyrogens and other entrained impurities, which are then led out through vertical apertures on the sides of the column and removed as blowdown. The process is then repeated in subsequent columns.
Plant steam is used to heat only the first column; thereafter the pure steam generated in each column is used to heat subsequent columns. As the pure steam condenses, the result is pyrogen-free WFI.
The new still meets all major compliance standards, including US, European and Japanese pharmacopoeia for WFI, ISO 9001:2000, GAMP, US cGAMP and FDA requirements.