736 Joinnal of Agriculture. Victoria. [10 Dec, 1917. 



bottom, and 4 feet in width at the top. On either side of the hot-air 

 chamber is a drying- chamber in which the trays are placed. Each of 

 these drying chambers is 18 feet in length, 7 feet in height, and 2-t feet 

 in width. The walls, instead of being vertical, are inclined toward the 

 heating chamber, which is thus made 3 feet narrower at top than at 

 bottom. Each drying chamber ha.s 22 slat runways extending through 

 its length, made of i x 1 inch slats nailed on edge to the studding. 

 These slats are 3^ inches apart from centre to centre, and are so ar- 

 ranged that the outer edge of each tray is 6^^ inches higher than the inner 

 side. As the trays used are 1 inch in depth, there is an interval of 

 2|- inches between the top of the fruit in one tray and the bottom of the 

 tray above. The inner wall of the tunnel, next to the hot-air chamber, 

 is built of 1-inch slats, which have intervals of 2|- inches between them, 

 and these slats are so spaced that the upper edge of each slat is just flush 

 with the top, while its lower edge is, of course, flush with the bottom of 

 the corresponding tray. The 2i-ineh spaces between trays are thus 

 freely open to the hot air chamber. On the outer side of the drying 

 chamber, the wall is also built of slats, but the intervals between these 

 become progressively wider from above downward. Above the upper 

 tray of the series the interval between slats is only 1-12 inch in width, 

 above the next it is increased to 2-12, above the next to 3-12, and each 

 successive interval is wider by 1-12 inch, so that the slit opposite the 

 outer edge of the lowest member of the series of 22 trays is 1 11-12 inches 

 in width. 



Warm air rises from the furnace room into the hot air chamber, and 

 thence passes laterally through the openings in the walls into the drying 

 chambers. Since there is at the opposite side of each tray a slit opening 

 into a space outside the outer wall of the drying chamber, the air moves 

 laterally across the face of the inclined tray, and esca.pes into this space 

 instead of rising through the trays above. The tendency of the warm 

 air to rise to the tojj of the hot-air chamber before passing laterally 

 over the trays is corrected by making the inlets into the drying chamber 

 all of the same width, while the outlets therefrom are successively wider 

 from above downward, as already described. (iSee Fig. XXI.) A very 

 uniform distribution of the warm, air is thus secured, the temperatures 

 on up)per and lower trays of the series diifering only by two to five 

 degrees. Consequently, this evaporator differs fundamentally from the 

 tunnel type in that all the fruit in any pair of chambers -is kept at a 

 uniform temperature. 



The second story of each unit has a pair of drying chambers identical 

 in size, construction, and caj^acity with the lower pair, but differing from 

 them in that they are inclined outward instead of inward, and in that the 

 outer wall has uniform air inlets 24 inches wide between trays, while the 

 inner wall has the graduated slits for the exit of air. The warm air, 

 after its passage through the lower drying chamber, i>asses into a space 

 between the drying chamber and the solidly-boarded, vertical wall of the 

 unit. This space is freely open above into the space between the upper 

 chamber and the vertical wall. Consequently, the warm air escaping 

 from the lower drying chambers rises in this space, passes from it into 

 the upper drying chambers, where it flows across the inclined trays t^ 

 escape through the graduated slits into a central space, from which a 

 ventilating shaft carries it through the roof. Since the central hot ;'iv 



