kes a comparatively light
and inexpensive door, and one that absolutely holds the heat. These
doors may be built either swinging, hoisting, or sliding.

[Illustration: Fig. 85. An Asbestos-lined Kiln Door of the
Hinge Type.]

In Figure 86 will be seen the Twin Carrier type of door hangers with
doors loaded and rolling clear of the opening.

[Illustration: Fig. 86. Twin Carrier with Kiln Door loaded
and rolling clear of Opening.]

[Illustration: Fig. 87. Twin Carriers for Kiln Doors 18 to 35
Feet wide.]

In Figure 87 will be seen the Twin Carrier for doors 18 to 35 feet
wide, idle on a section of the track.

In Figure 88 will be seen another type of carrier for kiln doors.

In Figure 89 will be seen the preceding type of kiln door carrier in
operation.

In Figure 90 will be seen another type of carrier for kiln doors.

In Figure 91 will be seen kiln doors seated, wood construction,
showing 3-1/2" x 5-3/4" inch-track timbers and trusses, supported on
4-inch by 6-inch jamb posts. "T" rail track, top and side, inclined
shelves on which the kiln door rests. Track timber not trussed on
openings under 12 feet wide.

[Illustration: Fig. 88. Kiln Door Carrier engaged to Door
Ready for lifting.]

In Figure 92 will be seen kiln doors seated, fire-proof construction,
showing 12-inch, channel, steel lintels, 2" x 2" steel angle mullions,
track brackets bolted to the steel lintels and "T" rail track. No
track timbers or trusses used.

[Illustration: Fig. 89. Kiln Door Carrier shown on Doors of
Wood Construction.]

[Illustration: Fig. 90. Kiln Door Construction with Door
Carrier out of Sight.]

[Illustration: Fig. 91. Kiln Door Construction. Doors Seated.
Wood Construction.]

[Illustration: Fig. 92. Kiln Door Construction. Doors Seated.
Fire-proof Construction.]

SECTION XIV

HELPFUL APPLIANCES IN KILN-DRYING

The Humidity Diagram

[Illustration: Fig. 93. The United States Forest Service
Humidity Diagram for determination of Absolute Humidities.
Dew Points and Vapor Pressures; also Relative Humidities by
means of Wet and Dry-Bulb Thermometer, for any temperatures
and change in temperature.]

Some simple means of determining humidities and changes in humidity
brought about by changes in temperature in the dry kiln without the
use of tables is a