US 5,343,632 A · Closed-loop drying process and system

Abstract

A dryer is designed as a closed system in which heated air used to dry the materials is continuously recycled within the drying compartment of the dryer without being discharged to the atmosphere, thus increasing the efficiency of the system while preventing the discharge of contaminated vapors to the atmosphere and also conserving energy which would otherwise be required to heat or air-condition the air drawn into the dryer from the building in which the dryer is located. A regenerative heat exchanger and an atmospheric cooler/condenser are provided in the dryer and condense and remove moisture from the saturated air and transfer the heat of condensation back into the air before the air is reheated and recycled back to the materials to be dried. The drying compartment may comprise an enclosed tunnel through which a rack of superposed trays are conveyed or may comprise some other conveying mechanism.

Claims28

Dependent claims

A dryer comprising:

(A) an enclosed housing having a drying compartment located therein for receiving materials to be dried in contact with a drying medium;
(B) a heating element located in said housing which heats said drying medium;
(C) means for dehumidifying said drying medium which includes a regenerative heat exchanger which is self-regenerative and which is located in said housing between said drying compartment and said heating element;
and
(D) means for recirculating said drying medium within said enclosed housing in a closed-loop manner from said heating element, through said drying compartment and said means for dehumidifying, and then back to said heating element without venting said drying medium outside of said enclosed housing.

2 more elements

A method of drying materials, said method comprising the steps of:

(A) inserting said materials in a drying compartment of an enclosed housing;
(B) heating a drying medium via a heating device;
then
(C) conveying said drying medium through said drying compartment in contact with said materials;
then
(D) dehumidifying said drying medium by conveying said drying medium through a regenerative heat exchanger located in said housing between said drying compartment and said heating element;
then
(E) conveying said drying medium back to said heating element without venting said drying medium out of said housing;
and then
(F) repeating said steps (B) through (E).

7 more elements

Dependencies are inferred from the claim text.

Closed-loop drying process and system

Life of this patent

Closed-loop drying process and system

Life of this patent

Abstract

Claims28