VACUUM TRAY DRYER  

Vacuum Tray Dryer is an enclosed, jacketed housing in which solids are placed on tiers of trays in the case of particulate solids or stacked in piles or shelves in the case of large objects. In Vacuum Tray Dryer heat transfer is done by use of heated shelves, radiator coils or refractory walls inside the housing. Uniform depth of loading in dryers is essential for consistent operation, minimum heating cycles or control of final moisture. After a tray has been loaded, the bed should be leveled to a uniform depth.

Control of drying cycle is maintained by controlling the vacuum. In general, trolleys are loaded on tracks fitted with flanged wheels to run inside the chamber. Trays are fabricated from non-corrosive metals, and a minimum clearance of 40 mm is maintained between the material in one tray and the bottom of the tray immediately above. Insulation of compartment is done which the help of insulation materials with lower thermal conductivity and having air pockets or void spaces within its configuration, thus minimizing the amount of heat transferred. Such material may be particulate or fibers with or without binders. Steam is the best heating medium. However, when steam is not available or the drying load is small, electric heaters are used. For temperatures above 200 C, indirect fired air heater or products of combustion can be used. Air filters are placed before the fan so that fresh air is drawn within the cabinet. Loading of trays is generally done between 10 to 100 mm while individual tray area lies between 0.5 to 1.0 sq. Meter.

DESCRIPTION:

The cabinet is of rectangular shape, outside body is fabricated from AISI 304 gr. Stainless steel, 12 Swg. thick & inside contact parts are made of AISI 316 gr. Stainless steel, 16 swg thick. The blower is mounted on the top left side of cabinet having S.S. impeller with aluminium boss. The impeller is driven by a combination of V-belt, pulleys and induction motor. Inlet air passes through a 20-micron filter before entering the cabinet. Air can be regulated by a manual damper positioned at the top of cabinet, left side provide with Limit Switch. Inlet air is heated with the help of a steam radiator positioned just below the blower. There is only one section of cabinet where number of trays are loaded on a trolley having shelves, each shelve containing 2 nos. of trays. The trolley is mounted on castor wheels and while the trolley is pushed the cabinet from the front side though trolley guider. The cabinet is having glass wool insulation all around its surfaces. The equipment is provided with temperature controller, steam control valve steam inlet, condensate outlet etc.