Separation of dried products from the air
Friday, March 2nd, 2012 5:42:24 by Ahmed Tariq
Separation of dried products from the air
The fourth and the last stage of the spray drying process is the separation of the dried product from the air. The recovery of the product from the dryer is carried out in a two point discharge design. Primary separation of
dried products takes place at the bottom of the drying chamber. A small fraction of the particles remain suspended in the air during the process whereas most of the dried particles are captured at the bottom of the chamber (Stanbury, 1984). The suspended particles
are recovered in the separation equipment downstream; cyclone with wet scrubber.
The degree of the separation in the chamber is greatly influenced by the location of the duct leaving the chamber, especially for the conical base chamber.
The arrangement selected depends on the product form and the collection equipment installed. The arrangement that gives a low loading of fines into the duct (a) does not necessarily result in high efficiency and low loss of
fines. The loading of the slightly larger particles into the duct recover some of the fines in the downstream cyclone due to the ability of large particles to entrain or agglomerate fines that would otherwise be lost (Endo, 2009).
The selected arrangement draws air to the side and it creates a lopsided (slightly angled) air flow pattern. This greatly interferes with the normal air flow and creates suction in the neighbourhood powder present at the walls.
This arrangement is especially used with heat sensitive products as any deposits forming on the exterior surface of the projected duct deteriorate the product quality.
Short URL: https://www.newspakistan.pk/?p=14489
Posted by Ahmed Tariq
on Mar 2 2012. Filed under Sci-Tech.
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