Roller grinding mill apparatus

• US 4,022,387 A
• Filed: 03/12/1976
• Issued: 05/10/1977
• Est. Priority Date: 03/12/1976
• Status: Expired due to Term

• Current Assignee: Williams Patent Crusher and Pulverizer Company
• Original Assignee: Williams Patent Crusher and Pulverizer Company
• Inventors: Williams, Robert M.
• Primary Examiner(s): Custer, Jr., Granville Y.
• Application Number:
  US05/666,407
• Time in Patent Office: 424 Days
• Field of Search: 241/129, 241/130, 241/131, 241/133
• US Class Current: 241/130
• CPC Class Codes: B02C 15/02 Centrifugal pendulum-type mills

Abstract

Roller grinding mill apparatus comprising a stationary bull ring which cooperates with a plurality of centrifugally operated grinding rollers and means for setting a predetermined gap space between the grinding rollers and the grinding face of the bull ring so that the grinding rollers will be unrestricted so as to move in radial directions in response to centrifugal force, but will not normally be permitted to contact the grinding face of the bull ring.

Claims

1. Roller grinding mill apparatus comprising a frame enclosing a space in which material to be ground is confined, a stationary bull ring fixed in said frame in position to have an inwardly presented cylindrically shaped grinding face, a plurality of grinding rollers in said enclosing space, means operably mounting said rollers for rotation about a common axis centered to said cylindrically shaped grinding face and for pivotal movement about axes perpendicular to said common axis of rotation and in planes parallel to said common axis of rotation and in radial directions toward and away from said grinding face, said operable mounting means providing for free movement of said grinding rollers away from said grinding face and limiting the radial movement toward said grinding face to a predetermined minimum gap spacing between said rollers and said grinding face without any material to be ground between said grinding rollers and said grinding face, and consisting in levered means and resilient elements to set said predetermined minimum gap spacing between said rollers and said grinding face in which said levered means is a hanger pendently supporting each rollers for pivotal movement in said planes parallel to said common axis and a lever arm on each hanger having a free end, and the resilient elements being located adjacent each lever arm free end in position to check lever movement thereby maintaining said gap spacing, means on said frame to admit material to said enclosing space above said bull ring, said material working down by gravity between said bull ring and grinding rollers to establish a layer of material of such thickness as to space said rollers from said bull ring face a distance greater than said minimum gap spacing, drive means connected to rotate said roller mounting means to generate a centrifugal force proportional to the speed of rotation urging said grinding rollers toward said grinding face whereby said operable mounting means permits said rollers to be free to move radially limited only by said minimum gap spacing, and air supply means on said frame including an air receiving bustle and ports opening between said bustle and the enclosing space in said frame below said bull ring, said ports directing air into the material to fluidize the material being ground.

2. The apparatus set forth in claim 1 wherein each lever arm is directed radially inwardly toward said common axis and moves in response to the pivotal movement of said hangers.

3. Roller grinding mill apparatus comprising a frame enclosing a space in which material to be ground is confined, a stationary bull ring fixed in said frame in position to have an inwardly presented cylindrically shaped grinding face, a plurality of grinding rollers in said enclosing space, means operably mounting said rollers for rotation about a common axis centered to said cylindrically shaped grinding face and for pivotal movement about axes perpendicular to said common axis of rotation and in planes parallel to said common axis of rotation and in radial directions toward and away from said grinding face, said operable mounting means providing for free movement of said grinding rollers away from said grinding face and limiting the radial movement toward said grinding face to a predetermined minimum gap spacing between said rollers and said grinding face without any material to be ground between said grinding rollers and said grinding face, said operable mounting means including a head member, arms extending radially from said head member and spaced circumferentially about the common axis of rotation, pivot bearing means on each arm defining an axis of movement which is horizontal and perpendicular to said axis of rotation, hanger means attached to each pivot bearing and pendently directed, said grinding rollers being supported by said hanger means, a stop arm on each hanger means adjacent said pivot bearing and adjacent arm of said head member, said stop arms extending inwardly toward said axis of rotation, and resilient means carried by said arms on said head member in position to be engaged by said stop arms and establish said predetermined minimum gap spacing.