Typically rotary sifters are gravity feed with a controlled feed or are fitted with a cyclone and rotary valve on the infeed and another rotary valve on the discharge. This increases capital and operational costs and requires a much larger area for installation.
The Fresco in-line rotary sifter is designed to operate as an integral part of the pneumatic conveying system. It can be installed directly into the pneumatic conveying line irrespective of whether it is a vacuum or pressure system.
Sifters are commonly used for classifying, grading, de-lumping and screening foreign matter such as fragments of packaging materials and insects etc, which inadvertently enter the process. The Fresco in-line rotary sifter works on the principle of product entering the rotary sifter via the pneumatic conveying line and is then 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 overs) pass along the screen until they are rejected into the sealed overs container. Particles passing through the screen are generally the desired product and continue into the downstream process via the pneumatic conveying line.
Installed directly into pneumatic conveying lines the Fresco in-line rotary sifter can operate between -50 and +80kpa. This covers most standard lean phase pneumatic conveying systems. Screens manufactured from punched plate or woven wire with apertures typically ranging from 250micron to 10,000micron are used.
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 integrality 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 even when under positive pressure.
The Fresco in-line rotary sifter is available in four sizes and differing materials of construction and finish to suit the 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 in-line sifter is suited to most applications.