30 CFR § 77.300
Thermal dryers; general.
On and after July 1, 1971 dryer systems used for drying coal at high
temperatures, hereinafter referred to as thermal dryers, including rotary
dryers, continuous carrier dyes, vertical tray, and cascade dryers,
multilouver dryers, suspension or flash dryers, and fluidized bed dryers,
shall be maintained and operated in accordance with the provision of
[36 FR 9364, May 22, 1971, as amended at 36 FR 13143, July 15, 1971]