10
From Spray Pond Bull. SP-51, Marley Co., Mission Woods, Kan., p. 3. From Spray Pond Bull. SP-51, Marley Co., Mission Woods, Kan., p. 3. FIG. 12-23 Spray-pond performance curve. FIG. 12-23 Spray-pond performance curve. FIG. 12-24 Spray ponds cooling curves for steam-condensing service. Temp., Woter Leaving Nozzles, Deg. F. FIG. 12-24 Spray ponds cooling curves for steam-condensing service. L h2 air out - hi air in _ h2 - 41.58 G water temperature in - water temperature out 10 Corresponding...
1283
FIG. 12-100 P-type ring dryer. Barr Rosin FIG. 12-100 P-type ring dryer. Barr Rosin Special designs of spray dryers may provide for cooling air to enter around the chamber, closed systems for the recovery of solvents, and air sweepers or mechanical rakes to remove dry product from the walls and bottom of the chamber. Some are followed by pneumatic conveyors as depicted in Fig. 12-101, in which drying air is diluted with cool air for product cooling before separation. Spray dryers may operate...
Application Of Psychrometry To Drying
In any drying process, if an adequate supply of heat is assumed, the temperature and rate at which liquid vaporization occurs will depend on the vapor concentration in the surrounding atmosphere. FIG. 12-35 Relationship between wet-weight and dry-weight bases. FIG. 12-35 Relationship between wet-weight and dry-weight bases. In vacuum drying or other processes containing atmospheres of 100 percent vapor, the temperature of liquid vaporization will equal or exceed the saturation temperature of...
Mechanicaldraft Towers
Two types of mechanical-draft towers are in use today the forced-draft and the induced-draft. In the forced-draft tower the fan is mounted at the base, and air is forced in at the bottom and discharged at low velocity through the top. This arrangement has the advantage of locating the fan and drive outside the tower, where it is convenient for inspection, maintenance, and repairs. Since the equipment is out of the hot, humid top area of the tower, the fan is not subjected to corrosive...
Schematic Of Tray Dryer
Stokes Vacuum, Inc. Price includes dryer, 15-lb in2 jacket, drive with motor, internal filter, and trunnion supports for concrete or steel foundations. Horsepower is established on 65 percent volume loading of material with a bulk density of 50 lb ft3. Models of 250 ft3, 325 ft3, and 400 ft3 have extended surface area. Stokes Vacuum, Inc. Price includes dryer, 15-lb in2 jacket, drive with motor, internal filter, and trunnion supports for concrete or steel foundations. Horsepower is established...
Humidity Charts For Solvent Vapors
Humidity charts for other solvent vapors may be prepared in an analogous manner. There is one important difference involved, however, in that the wet-bulb temperature differs considerably from the adia-batic-saturation temperatures for vapors other than water. Figures 12-37 to 12-39 show humidity charts for carbon tetrachloride, benzene, and toluene. The lines on these charts have been calculated in the manner outlined for air-water vapor except for the wet-bulb-temperature lines. The...
Rotary Dryers
Description A rotary dryer consists of a cylinder, rotated upon suitable bearings and usually slightly inclined to the horizontal. The length of the cylinder may range from 4 to more than 10 times its diameter, which may vary from less than 0.3 to more than 3 m. Feed solids fed into one end of the cylinder progress through it by virtue of rotation, head effect, and slope of the cylinder and discharge as finished product at the other end. Gases flowing through the cylinder may retard or increase...
Batch Throughcirculation Dryers
In one type of batch through-circulation dryer, heated air passes through a stationary permeable bed of the wet material placed on removable screen-bottom trays suitably supported in the dryer. This type is similar to a standard tray dryer except that hot air passes through the wet solid instead of across it. The pressure drop through the bed of material does not usually exceed about 2 cm of water. In another type, deep perforated-bottom trays are placed on top of plenum chambers in a...
1
FIG. 12-54 Three types of tunnel dryers. Van Arsdale, Food Ind. 14 10 , 43 1942 . FIG. 12-54 Three types of tunnel dryers. Van Arsdale, Food Ind. 14 10 , 43 1942 . ous common materials. Performance data from several commercial through-circulation conveyor dryers are given in Table 12-16. Labor requirements vary depending on the time required for feed adjustments, inspection, etc. These dryers will consume from 0.9 to 1.1 kg of steam kg of water evaporated. Thermal efficiency is a function of...
Use Of Psychrometric Charts
Three charts for the air-water vapor system are given as Figs. 12-1 to 12-3 for low-, medium-, and high-temperature ranges. Figure 12-4 shows a modified Grosvenor chart, which is more familiar to the chemical engineer. These charts are for an absolute pressure of 1 atm. The corrections required at pressures different from atmospheric are given in Table 12-2. Figure 12-5 shows a psychrometric chart for combustion products in air. The thermodynamic properties of moist air are given in Table 12-1....