| 摘要 |
The method for the cooling preparation of bulk materials, particularly of molding sand for use in foundry practice, creates, in one working operation, which is divided into five phases, bulk material mixtures that are ready for immediate use. In the first filling phase, the mixing chamber (7) is filled with bulk material, whereupon the bulk material is set in motion and stirred up by means of mixing elements (12) and swirling devices (15). The subsequent cooling phase is initiated by spraying water into the mixing chamber and by supplying cooling air and removing the same by suction. During this cooling phase, the bulk material is cooled down by condensation cooling while maintaining a nearly constant humidity of 3 % and the aggregates are introduced into the bulk material. Immediately after this cooling phase, the humidity of the bulk material is increased by reducing the supply of air and the suction power, and the mixing is intensified by increasing the number of revolutions of the mixing element (12) and of the swirling device (15). This results in a homogeneous mixing of the bulk material, and the aggregates can react with the bulk material as desired. After the mixing phase, the emptying phase ensues upon attaining the desired respectively set humidity, whereby the finished bulk material mixture is removed from the mixing chamber (7) via a discharge opening (16). This results in being able to advantageously prepare, typically in a period of less than 3 minutes, the bulk material initially having a temperature of up to 150 DEG C for immediate reuse. |
