Drying Lost-Foam Molds

DAVRON TECHNOLOGIES INC. developed a gas-powered continuous conveyor oven to dry moisture from slurry on ceramic filter molds manufactured in a lost-foam casting process. With a 15-minute drying cycle, the DTI-223 continuous conveyor oven evaporates 1,121 lb. of moisture every hour. Typically, 190 molds per hour are processed through the oven and drying time can be adjusted depending on product requirements.

To dry the ceramic slurry, the DTI-782’s conveyor system moves products through three separate, temperature-controlled zones on a polypropylene mesh belt. Each zone uses one full modulating natural-gas burner, two circulation fans, and one exhaust fan. Each zone can be programmed to operate between 180ᴼF and 400ᴼF, with a maximum temperature of 450ᴼF.

The conveying system uses a variable-frequency drive (VFD) for speed adjustment, and the entire oven is controlled by a PLC. 

The useable dimensions of DTI-223 are 3 ft. 2 in. wide X 6 in. high X 98 ft. 4 in. long. The continuous conveyor oven interior is made out of 16-gauge aluminized steel backed by four inches of eight-pound-density mineral wool insulation. The structural steel frame that holds the interior chamber is covered in 16-gauge carbon-steel and finished with high-temperature paint.

Davron designed the DTI-223 based on two criteria provided by the client: the amount of moisture to be removed from each filter and the production rate. Davron did extensive testing to determine the temperature profile needed to meet these requirements and used this information as the basis for the custom design of the DTI-223.

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