The system included discharge from 1000kg bulk bags, transfer via flexible conveyors and vacuum transfer systems to mixing vessels. The sorbitol was discharged through Fresco's own rotary sifters ensuring all lumps and foreign matter such as fragments of packaging materials and insects, were removed from the process.
The Fresco rotary sifter works on the principle that product entering the rotary sifter via gravity is fed into the sifting zone by means of an internal screw auger. In the sifting zone the material passes along a cylindrical screen aided by 5 rotating single row brushes or beaters, which sweep the material through the screen.
The material is separated into thrus and overs with the particle size separation depending on the aperture of the screen. Particles too large to pass through the screen (called "over's") pass along the screen until they are rejected into the sealed over's container. Particles passing through the screen are generally the desired product and continue into the downstream process. Access for regular screen inspections and cleaning is via the side access door fitted as an option depending on the application.
As sorbitol is a hazardous dust when mixed with certain concentrations of air the electrical motor and safety lockout switches were DIP Zone 22 rated.
The rotary sifter screens were manufactured from T430 magnetic stainless steel mesh which if ruptured by a heavy metal object would be captured by the downstream rear earth grate magnets fitted below the rotary sifter. Designed for single particle size separation the screen is fitted to a support frame that is accessed via the swing end door. The screen can be visually inspected by the operator in minutes without the use of tools. This simple operation ensures the integrity of the product entering the process is not compromised by a hole in the screen. O-ring seals on the access door ensure a dust tight operation.
The Fresco rotary sifter is available in four sizes and differing materials of construction and finish to suit any customer's application and budget. All models are fitted with our unique lip seal and interlocking drive arrangement. The internal rotor is dynamically balanced and the end bearing mounts are laser aligned providing an extremely smooth, quiet operation.
The screw and brush section are easily removed leaving the stub shafts secured in the twin bearing mounts and shaft seals. This reduces the damage on shaft seals due to operator error. With the capability of handling a vast range of products from very fine powders to coarse granules and beads our standard sifter is suited to most applications.
To find out more about how Fresco can help customise a solution for you please visit www.frescosystems.com.
