Apparatus for the continuous mixing of granular materials

Abstract

A mixing apparatus adapted for use with granular or semi-solid material and embodying a mixer trough within which are disposed two parallel companion shafts each of which has mounted thereon a linearly straight row of flat slanting parallel mixing blades .Iadd.of interrupted-elliptical shape.Iaddend., the two rows of blades functioning when the shafts are rotated in opposite directions to propel the material forwardly while at the same time exerting thereon a slicing action whereby progressively diminishing masses of the material are tossed from side to side and are repeatedly sliced into smaller increments as they progress along the trough.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is: 
     
       1. In a mixing apparatus for granular material, in combination, an elongated mixing trough providing a longitudinal flow path and having a receiving and a discharge end, a pair of parallel companion shafts rotatable in said trough, a plurality of axially spaced sloping parallel interrupted-elliptical disk-like mixing blades on each shaft, the blades on the two shafts having equal but reverse pitch angles and being disposed in transverse pairs, said blades, in one position of the shafts, projecting predominately laterally in the same direction, the maximum radial projection of the blades from the shaft being slightly less than the distance between said shafts, and means for rotating said shafts in unison and in opposite directions whereby the blades of each pair traverse a common portion of said flow path alternately. 
     
     
       2. In a mixing apparatus, the combination set forth in claim 1 and wherein the blades on each shaft are effectively disposed entirely on one side of a longitudinal axial plane whereby overlapping of the paired blades is avoided. 
     
     
       3. In a mixing apparatus, the combination set forth in claim 1 and wherein said mixing trough is provided with a divided trough bottom establishing a pair of trough channels along said flow path and the surfaces of the channels are extended surfaces of revolution which are generated by revolution of said blades about the axes of the companion shafts. 
     
     
       4. In a mixing apparatus, the combination set forth in claim 3 and wherein each .[.semi-elliptical.]. .Iadd.interrupted-elliptical .Iaddend.blade has a major and a minor axis both of which intersect the longitudinal axis of the associated companion shaft, the minor axis extending at a right angle to said longitudinal axis and the major axis being inclined relatively thereto. 
     
     
       5. In a mixing apparatus, the combination set forth in claim 4 and wherein said trough channels are separated by a linear saddle peak. 
     
     
       6. In a mixing apparatus, the combination set forth in claim 4 and wherein the pitch angle of each blade is on the order of 45°. 
     
     
       7. In a mixing apparatus, the combination set forth in claim 4 and wherein each blade is in the form of an ellipse which is divided linearly along its major axis so as to define a half-ellipse. 
     
     
       8. In a mixing apparatus, the combination set forth in claim 1 and wherein each blade has a portion thereof which projects laterally from its associated shaft in a direction opposite to said predominant direction whereby, upon rotation of said shafts in opposite directions, progressive overlapping of said latter portions of the paired blades periodically takes place. 
     
     
       9. In a mixing apparatus, the combination set forth in claim 1 and wherein each blade is fixedly mounted on a central tubular sleeve-like hub, the various hubs are telescopically and removably mounted on the respective companion shafts in end-to-end contiguity, and means are provided for preventing both angular turning and longitudinal shifting of the hubs on their respective shafts. .Iadd.10. In a mixing apparatus, the combination set forth in claim 1 and wherein the blades on each shaft are the same in size and shape, are arranged in registering relation, and are all inclined in one direction. .Iaddend. .Iadd.11. In a mixing apparatus, the combination set forth in claim 10 and wherein each blade is substantially semi-elliptical and has its dividing line along its major aixs. .Iaddend. .Iadd.12. In a mixing apparatus, the combination set forth in claim 10 and wherein each blade is substantially three-quarters elliptical. .Iaddend. .Iadd.13. In a mixing apparatus, the combination set forth in claim 10 and wherein each blade is flat and imperforate. .Iaddend.