Ennigerloh, June 2012 – The L. B. Bohle Maschinen + Verfahren GmbH product range of proven fluid bed systems extends from the smallest Bohle Fluid Bed System BFS 3 through to the “flag ship“ BFS 480. At this year’s ACHEMA, the granulation and coating specialists will be presenting the further development of the “bestseller” in the medium range – the BFS 240.
Like the small and big systems of the BFS series, the optimised granulation and drying system offer numerous advantages and various options in pharmaceutical production. Thanks to the tangential spray system, the BFS 240 is a highly efficient machine. In addition to highly efficient drying, the system is equipped with eight tangential spray nozzles and is suitable for granulation and pellet-coating. This decisive advantage eliminates the need of retrofitting the system when changing from granulation to coating. Through the tangential-spray technology, this new processing design is much more robust than traditional Wurster technology. Moreover, fewer components ensure long service life.
In addition to the reduced overall height and the tangential-spray technology, exterior access to the spray nozzles is ensured at any time during granulation and coating. This allows the operator to interfere quickly if one of the nozzles is not working correctly. The special spray nozzles in the BFS 240 have been designed for direct injection to the product bed near the distributor bottom. This prevents caking at the spray head and enables homogenous and fine spraying of the product. The airflow also keeps the product at a distance to the nozzle exit, allowing optimum fluid distribution.
Up to 240 kilograms
The working volume of the BFS 240 is up to 480 litres. This is equivalent to a product batch size of around 240 kgs. Rear fastening enables the counterbalance design of the process bowl without lateral support. This allows easy operator access and better outer cleanability. New to Bohle’s fluid bed system generation is the fastening of sight glass ports without screws and intrusive fasteners for easy cleaning and unobstructed product visibility. The integration now visually looks like a single piece. Integration of a fluid bed system into pharmaceutical production is often associated with space problems. The Bohle system, however, uses space very efficiently. In comparison to traditional fluid bed systems, the BFS features a relatively large distributer bottom allowing high air flow of up to 7,000 m3 per hour.
Dust-free suction and discharge of the product bowl is performed through the use of a newly developed patented multi-functional valve directly above the distributer bottom. The overall design of the BFS results in substantial ergonomic benefits, which means major advantages in cleanability and processing in comparison to other existing fluid bed systems on the market. The low position of the valve allows easy operator access. The BFS contains fewer gaskets, valves and vents, which makes cleaning fast and easy. The tangential airflow near the bottom allows for excellent product discharge; this is supported by the conical distributer bottom developed by Bohle. It eliminates the need for lifting the product container from the process bowl and docking the discharge funnel. The BFS comes with a hinged process bowl which can be swivelled sideways, eliminating the need to disconnect media supply lines. This feature permits effortless interior access for inlet air inspection and dismantling the distributor bottom, if necessary.
Twelve individual filter bags
Besides the distributor bottom, the filter unit is an essential component in the fluid bed system. The traditional filter technology has been further advanced in the new fluid bed system generation. Twelve individual filter bags are used in the BFS 240, which are cleaned separately through pressure surge. Cleaning times (opening time of the filter exhaust valve), cleaning pressure and cleaning intervals are freely configurable. This results in optimised and significantly shorter processing time. Furthermore, the complete filter unit can be lowered. Tools are unnecessary for filter removal. Damaging clamps for filter assembly have been entirely abandoned. The filter bags are first fastened on the supporting basket upper section with an elastic band. Tight clamping is performed through inflatable seals when reaching the upper end position of the movable filter unit.
“At the ACHEMA we will be presenting the further optimised BFS 240 with the goal of setting a clear standard”, said Lorenz Bohle. “The potential of a fluid bed system is a vital element of our growth strategy”.