subject: Fluid Bed Dryer Filters [print this page] Fluid bed dryer is used in the production of a wide range of industrial chemicals, for example production of pharmaceuticals or dye-stuffs. Essentially, a fluidised bed dryer consists of a large pan which is filled with wet particulate material. Warm air, the temperature of which can be closely regulated is blown into the bottom of the pan so that the particles become fluidised and behave like a fluid, attractive forces between the particles such as electrostatic or capillary water film bonding being broken down. The air acts to vaporise the water present in the wet material, and the air with entrained water vapour is drawn out from above the fluid bed through a fluid bed dryer filter, to separate entrained dust (largely derived from the solids fraction of the particulate material) from the exhausted air stream.
It is an object of the invention to provide a fluid bed dryer filter which is so constructed that these problems with known filters of this kind can be overcome or ameliorated.
In accordance with the invention, a fluid bed dryer filter comprises a membrane having a plurality of openings therein, a respective filter bag/or pocket for attachment to the membrane so that each opening in the membrane admits to the interior of a filter bag or pocket, characterised in that each pocket is detachably attached to the membrane by means of a clamping device, and that the edge of each aperture in the membrane is formed to be stiff and shape-retaining.
The construction described has advantages with respect to known fluid bed dryer filters, in that the individual filter bags 17 are each separately removable for replacement or repair from the filter assembly, and this can be done on site. The time consuming operation of stitching each of up to 30 filter bags to the membrane sheet is avoided, as is the risk of distortion of the sheet if stitching is earned out incorrectly.
