Drying device and continuous granule production system

An airflow drying device configured to dry wet granulated substances with hot air, the airflow drying device comprising:

• a granulated substance introduction portion that includes a granulated substance inlet, into which the granulated substances are to be put, and a hot air inlet, through which the hot air is to be supplied;
• a dry process portion configured to follow the granulated substance introduction portion and communicate with the granulated substance introduction portion and through which the granulated substances are to flow together with the hot air;
• and
• a product ejection portion configured to follow the dry process portion and communicate with the dry process portion and from which the granulated substances are to be discharged together with the hot air after passage through the dry process portion, wherein:
• the dry process portion includes a processing pipe that is a tubular member having an annular shape and a constant diameter, and the processing pipe is positioned with an inclination of 45 degrees or less to a horizontal direction with the tubular member winding one or more times,
• the processing pipe comprises a plurality of processingpipe units with a curved portion formed of one member having the constant diameter,
• the processing pipe is dividable along a circumferential direction at each of multiple stages so as to facilitate cleaning and visible checking of an inner portion of the processing pipe, and
• the airflow drying device is configured to exert a centrifugal force on the granulated substances while the granulated substances flow through the processing pipe and are being dried by the hot air such that the wet granulated substances remain granules when being dried, without being crushed or turned into powder.