Cylindrical dryer having conduits provided within a plurality of holding plates

Abstract

A dryer uses conduits to carry a heating medium, such as steam, to heat the outer surface of the dryer. The volume of steam is successfully reduced to non-explosive levels and the shell need not be designed to prevent an explosion. Conduits may be formed through the shell itself or grooves may be formed on the inner surface of the shell, with the conduits retained within the grooves. Also, the conduits can be placed against the inside surface of the dryer and a material, such as zinc, can be filled in about the conduits. The material serves to both retain the conduits in place and thermally couple the conduits to the dryer to assure efficient heat transfer between the conduits and dryer. These modifications relieve the dryer from the Unfired Pressure Vessel classification to the classification of a piping assembly under ASA code regulations. This results in savings in operation safety, installation cost and operating costs due to the absence of costly inspections. Transportation costs are lowered by manufacturing a plurality of holding plates which would be transported to the location of use at which point the Yankee dryer will be constructed. It is contemplated that the plurality of holding plates would not require a shell surrounding the exterior of these holding plates. Additionally, the thermal gradient on the exterior of the Yankee dryer will be controlled through the use of a plurality of auxiliary supply and exhaust conduits.

Dependencies are inferred from the claim text.