kinds and thicknesses of material
to dry in small quantities of each, such as:

Planing mills;
Chair factories;
Furniture factories;
Sash and door factories; etc.

The "Tower" Dry Kiln

The so-called "Tower" dry kiln (see Fig. 38) is designed for the rapid
drying of small stuff in quantities. Although the general form of
construction and the capacity of the individual bins or drying rooms
may vary, the same essential method of operation is common to all.
That is, the material itself, such as wooden novelties, loose staves,
and heading for tubs, kits, and pails, for box stuff, kindling wood,
etc., is dumped directly into the drying rooms from above, or through
the roof, in such quantities as effectually to fill the bin, from
which it is finally removed when dry, through the doors at the bottom.

These dry kilns are usually operated as "Blower" kilns, the heating
apparatus is generally located in a separate room or building adjacent
to the main structure or drying rooms, and arranged so that the hot
air discharged through the inlet duct (see illustration) is thoroughly
distributed beneath a lattice floor upon which rests the material to
be dried. Through this floor the air passes directly upward, between
and around the stock, and finally returns to the fan or heating room.

This return air duct is so arranged that by means of dampers, leading
from each drying room, the air may be returned in any quantity to the
fan room where it is mixed with fresh air and again used. This is one
of the main features of economy of the blower system of drying, as by
the employment of this return air system, considerable saving may be
made in the amount of steam required for drying.

[Illustration: Fig. 38. Exterior and Sectional View of a
Battery of Tower Dry Kilns. This is a "Blower" or "Hot Blast"
type, and shows the arrangement of the fan blower, engine,
etc. This type of dry kin is used principally for the
seasoning of small, loose material.]

The lattice floors in this type of dry kiln are built on an incline,
which arrangement materially lessens the cost, and increases the
convenience with which the dried stock may be removed from the bins or
drying rooms.

In operation, the material is conveyed in cars or trucks on an
overhead trestle--which is inclosed--from which the material to be
dried is dumped directly into the drying rooms or bins, through
hoppers arr