In some instances, these kilns are built less in height and up against an embankment so that teamloads of material may be run directly onto the roof of the kilns, and dumped through the hoppers into the drying rooms or bins, thus again reducing to a minimum the cost of this handling.
The return air duct plays an important part in both of these methods of filling, permitting the air to become saturated to the maximum desired, and utilizing much of the heat contained therein, which would otherwise escape to the atmosphere.
The "Tower" kiln is especially adapted to factories of the following class:
- Sawmills;
- Novelty factories;
- Woodenware factories;
- Tub and pail factories; etc.
The "Box" Dry Kiln
The "Box" kiln shown in [Figure 39] is an exterior view of a kiln of this type which is 20 feet wide, 19 feet deep, and 14 feet high, which is the size generally used when the space will permit.
Box kilns are used mostly where only a small quantity of material is to be dried. They are not equipped with trucks or cars, the material to be dried being piled upon a raised platform inside the drying room. This arrangement, therefore, makes them of less cost than the other types of dry kilns.
They are particularly adapted to any and all species and size of lumber to be dried in very small quantities.
