| 摘要 |
PURPOSE:To dehumidify and cool molding sand quickly by effective utilization of a slight time zone during processing by applying a heat treatment by a heating medium to the molding sand contained in the working chamber of a treating tank then evacuating the working chamber automatically. CONSTITUTION:The molding sand in a hopper 19 in the upper part of a treating tank 1 is charged at a prescribed rate into the tank 1 by opening a damper 4, and a heating mechanism is operated by the closing signal of the damper 4. Then, a heating medium is supplied into heating pipings 7 to heat the molding sand charged in a working chamber 13 successively. Upon elapsing of the time zone when the molding sand attains a prescribed temp., the heating mechanism stops, and a vacuum mechanism is operated. Then, powerful attraction forces are generated around the fine hole A groups of evacuating pipes 10, and the inside of the chamber 13 is evacuated instantaneously, whereby the molding sand is cooled and dehumidified. When the set time for the evacuation elapses, the ejection of air from air nozzles 5 and the opening of the damper 4a are accomplished simultaneously, and the molding sand is fed to the next stage through a pneumatic pipe 14. |
