Longitudinal mixing occurs during the fluidization process. As a result, if the process time is long, the difference in residence time of the individual particles is too great. This can lead to damage to the product.
Yet there are products that require long processing. So this would have to occur in a Fluid Bed with a very high length to width ratio. This is usually not desirable, among other things because it takes up too much space.

Our solution for this problem is sub-fluidization. In this process, the product remains on the verge of fluidization. Our unique drive concept, combined with a rotary weir, makes residence times up to 2 hours possible. The layer thickness of the product can vary from 5 to 60 centimeters with this process method.

Advantages of the Sub-Fluid Bed:

• There is hardly any or no longitudinal mixing. Differences in residence times are kept to a minimum and the various particles are processed uniformly.
• Less fluidization gas is needed for the process than with complete fluidization. This means smaller peripherals and lower energy consumption.
  With a Fluid Bed and sub-Fluid Bed a range of products can be processed which previously could only be processed with a belt dryer.

The Ventilex sub-Fluid Bed has amply proved its quality in processing, among others: cereals, seeds, nuts, beans, croutons, breakfast cereals, cheese, meat, fibers, extrudates, pellets and plastic granulates.