Drying apparatus for aqueous coated articles and method

In a method of drying aqueous coatings applied to fruit including the steps of:

• providing a plurality of intercommunicating substantially closed chamber sections having a continuous path through said sections along which a strata of fruit is advanced with openings in said path and fruit strata generally uniformly arranged along the length and width of said path;
• intermixing fresh and recycled air and heating said air mixture to a selected temperature and at a selected humidity;
• directing said intermixed air beneath said path of said first chamber section for upward passage through said openings and fruit strata for drying contact with said fruit on said path;
• removing drying air from the chamber space above said path and directing such removed air to the chamber space below said path in the next adjacent downstream closed chamber section;
• passing drying air in said adjacent chamber section upward through said openings in said path and fruit strata for further drying of fruit as it is moved along said path;
• removing air from said adjacent closed chamber section above said path and directing it downstream to adjacent chamber sections for further drying of fruit in like manner;
• and returning a selected portion of said air from said last downstream closed chamber section to said upstream end of said path for intermixing with fresh air for recycling thereof.

In a dryer apparatus for articles such as fruit and the like to which applications of aqueous coatings have been made, for removal of water from said coatings on said fruit, the combination of:

• a dryer housing means providing inlet and outlet ends and a passageway means for returning air from adjacent said outlet end to said inlet end;
• a heat exchanger means adjacent said inlet end;
• fresh air inlet means adjacent said inlet end;
• first blower means for blowing intermixed heated and recycled air of selected temperature and humidity in said inlet end;
• a continuous conveyor for articles extending through said housing means;
• said housing means including an inlet end housing section, an outlet end housing section, and one or more intermediate housing sections;
• each of said housing sections providing a substantially closed chamber about the portion of the continuous conveyor passing therethrough and having a plenum lower chamber space beneath said conveyor and an upper chamber space above said conveyor;
• said conveyor and said articles thereon providing a perforate zone for passage of intermixed heated air from said lower chamber spaces in each housing section to said upper chamber spaces;
• blower means for moving the same volume of said intermixed heated air continuously through and to each of said housing sections including a blower at each housing section for removing air from the upper chamber space above said conveyor in each chamber section and for directing and introducing said removed air of the same volume into the lower plenum chamber space in the next adjacent downstream chamber section for passage through the perforate zone in said latter chamber section.