MALCOLM L MACKAY
Engineers in Buffalo, NY

4106116, Aug 8, 1978

Jan 7, 1977

5/757737

Malcolm H. MacKay - West Seneca NY

B01F 726, B01F 1502

366144

An apparatus of the shot mill type includes a substantially vertical vessel, preferably cylindrical, containing shot for use as a dispersing media (also useful for deagglomerating and size-reducing material being dispersed), a bottom inlet for a mixture of particulate material to be dispersed and liquid vehicle for it, and a top outlet, a substantially vertical and axially rotatable agitator and a stationary screen in the vessel at the top thereof through which the dispersed material passes and through which the dispersing media does not pass. In preferred embodiments of the invention the pressure at the top of the vessel is kept low so as to obviate pressure sealing, the inlet includes a removable sacrificial fitting in a side wall of the vessel near the bottom, the vessel walls and bottom are jacketed for temperature control, a washing screen is present at the top circumferential portion of the vessel to facilitate removal of undersized media during washing, the vessel bottom includes a screened outlet to allow selective removal of particulate material and vehicle, or media and to facilitate washing of the vessel, means are provided on the shaft near the screen for preventing buildup of particulate material and sealing is effected between the rotating shaft and stationary screen by means of a bearing on the shaft and a bushing held to a screen holder, both bearing and bushing being of a hard material, such as tungsten carbide.