Ring Granulator is an ideal machine for crushing coal to a size suitable at power stations prior to pulverization.
Developed from the conventional hammer mill by substituting rings for hammers its unique action results in a minimum of both oversize and fines thereby improving efficiency.
It comprise with screen plate / cage bar steel box with an opening for the introduction of the material to be crushed set to one side in the top cover. A sloping breaker plate arranged, on a hinged cage frame is set to one side of the feed entry and a power driven horizontal main shaft passes from frame side to frame side parallel to this breaker plate.
This main shaft carried in roller bearings from the box sides, supports a number of circular discs fixed at regular intervals across its length within the frame.
A series of bars running parallel to the main shaft, pass through these discs near their outer edges. The bars are equally spaced about the main shaft center and carry a series of rings which are free to turn on the bars irrespective of the main shaft rotation.
Below the shaft / disc / ring assembly, called collectively, the rotor assembly, the movable cage frame is carried round at a radius marginally larger than that of the ring running periphery. According to the duty required the cage area can be left open or fitted with screen plates / cage bars and the entire cage assembly is set in close proximity to the rings by screw jack mechanism operated from outside of machine.