Mixing method of powdered or granular material utilizing pulsating vibration air

A pneumatic transport system for powdered or granular material utilizing pulsating vibration air, comprising:

• a tank having a porous bottom plate for storing powdered or granular material thereon;
• a material collecting tank for receiving powdered or granular material pneumatically transported from said tank, said material collecting tank being connected to a material transport pipe including valve means therein;
• pulsating vibration air generation means connected to an air source via a first conduit and connected to the lower part of said tank below said porous bottom plate via a second conduit, whereby in a mixing operation said valve means is closed when the pulsating vibration air generated at a fixed frequency by driving said pulsating vibration air generation means is supplied into said tank below said porous bottom plate of said tank upwardly, thereby the powdered or granular material stored on said porous bottom plate in said tank is lifted up and mixed together uniformly by convection generated in said tank, and in a transporting operation said valve means is opened while the pulsating vibration air generated at a fixed frequency by driving said pulsating vibration air generation means is supplied into said tank below said porous bottom plate of said tank, thereby the powdered or granular material stored on the porous bottom plate in said tank is pneumatically transported into said collecting tank;
• material recovery means above said tank, said material recovery means comprising:
• a cyclone body having at the upper part an air outlet connected to a filter for separating fine particles dispersing in said tank from air and at the lower pat a material discharge port with said valve for selectively opening or closing directly connected to said tank in which said valve is opened when returning powdered or granular material collected by said body;
• a material recovery conduit connected to said tank from a side wall of said cyclone body;
• and
• another valve further provided on said material recovery conduit in which said another valve is opened during the mixing process in order to introduce fine particles dispersing in said tank into said cyclone body.