FitzMill With Containment And Optional Inert Processing

The Product Containment System (PCS) was developed to contain product inside the process components of the Fitzmill during processing in order to prevent airborne dust from escaping into the atmosphere. A second objective of this system is to facilitate operation in an inert environment. The method used to contain the product is similar to isolator technology. The process area is kept under a slight negative pressure to insure that no powder migrates to the outside. Clearly a tightly sealed machine is critical to this design, however a number of other components are also required to allow for effective operation.

The Product Containment System features several primary filters in the machine discharge which are connected to a vacuum system in order to maintain the proper condition inside the milling chamber. A Fitzpatrick exclusive backpurge cartridge (patent pending) is utilized to draw process gas in from one filter, in order to backpurge and thereby clean another filter. This eliminates using external compressed gas to backpurge the filters. Benefits of this new system include:

· Backpurge cartridge is effective at keeping filters clean without pressurizing process area
· Inert processing with atmosphere monitoring is possible with minimal Nitrogen consumption
· PCS components are easy to clean and filters are disposable
· Minimal internal surface area with vertical orientation reduces product hang up and loss

And it is effective….
An independent testing company (BroadSpire) was contracted to verify the effectiveness of the PCS system according to preliminary SMEPAC protocol. A surrogate material was used. The air surrounding the equipment was checked for the presence of the surrogate material before and during the test. The test consisted of processing the material from a feed drum, through the mill, and into a discharge drum. The results are impressive.

The amount of airborne surrogate, which was detected by a fixed sampler close to the machine as well as a sampler mounted on the operator, was virtually undetectable by the instruments over the course of the 15-minute test. The instruments had a detection level of less than 10 nanograms. This demonstrates that the PCS system contains the product absolutely during processing. The containment challenge is to insure product doesn't escape the system as product is brought to and away from the machine. The use of containment valves or other techniques is required.

The Inert Processing system can be added a PCS FitzMill as an option in order to maintain the process atmosphere at a desired oxygen level (typically less than 5%). The inerting system includes complete instrumentation and controls for the nitrogen supply. The instrumentation both monitors the Nitrogen that is being added to the mill, as well as the Oxygen and Vacuum level that is being maintained in the processing area.

The Product Containment and Nitrogen Inerting Systems can be supplied for either the D6A, DAS06, or larger FitzMill designs.

For additional information please contact Scott Wennerstrum, The Fitzpatrick Company, 630-530-3333 info@fitzmill.com, www.fitzmill.com