B4-FV-18-D n additional hooktype quick coupling with a hose f Bevel-helical speed reducers B4

Flender/Flender Gear Units/Bevel-helical speed reducers B4

yer is similar in appearance to the double- drum dryer but is quite different in its operation. The two drums occupy the same general position as in double-drum dryer but rotate away from each other at the top and are notspaced closely together. The fruit or vegetable pulp is fed onto the metal surface of thedrums by means of various types of feeders. The dry product is removed by doctor blades.Depending on the material properties, the product is removed in the form of powders,akes, or webs. The drum system can be entirely enclosed in hood for vacuum operationor for supply of the necessary amount of drying air. Thus, organic solvents or volatiles can be recovered in this process. typical example of single-drum drying operation is the drying of mashed potato or apricot pulp (to produce sheet of apricot; see Fig. .Double-drum or twin-drum dryers are in commercial use for drying apple sauce, mashedwhite potatoes, and purees of tomato, pumpkin, and banana. Success has been reported indrum-drying mixtures of apple sauce with strawberry, cranberry, blueberry, black currant,loganberry, and banana (. 6 Grabowski et al. Fig. 1 Double-drum dryer. (From Ref. 1.) Special types of contact dryersplate dryers with rotating radial armsare dedi- cated to drying of solid particulate materials (5,. All contact drying units may operateunder vacuum, at atmospheric pressure, or in gas-tight chambers. 3.4 Foam Drying Two foam drying methods are of practical importance: foam mat and foam spray drying. Foam mat dried fruit or vegetable powders have fewer heat-induced changes in color andavor than conventional spray dried or drum dried products. product with density lessthan that in conventional dryer is obtained. The product density is about equal to thedensity of instantized or agglomerated powder. stable gas-liquid foam is the primary condition for successful foam drying. Glyc- erol monostearate, solubilized soya protein, and propylene glycol monostearate are the typical ad