Patent Publication Number: US-6217209-B1

Title: Dry material and slurry processor

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This is a continuation non-provisional patent application of U.S. Non-provisional patent application Ser. No. 08/982,686, entitled DRY MATERIAL AND SLURRY PROCESSOR and filed on Dec. 2, 1997, by Ernst R. Muller et alia, [which is scheduled to issue on even date herewith as ] now U.S. Pat. No. 6,015,228, issued Jan. 18, 2000, the disclosure of which is incorporated here by reference, which is a continuation patent application of U.S. Non-provisional patent application Ser. No. 08/978,079, entitled DRY MATERIAL AND SLURRY PROCESSOR and filed on Nov. 25, 1997, by Muller et alia, the disclosure of which is incorporated here by reference, now abandoned, which is a continuation in part application of U.S. Provisional patent application Ser. No. 60/031,456, entitled DRY MATERIAL AND SLURRY PROCESSOR and filed on Nov. 26, 1996, by Muller et al., now expired, the disclosure of which is incorporated here by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     The invention relates to material processing and more particularly to the processing of dry and granular materials, liquids, and slurries to obtain a homogenous compound, whether dry or liquid. 
     In many commercial settings, including commercial baking or chemical mixing processes, for example, materials commonly need to be sifted or mixed. Traditionally, this process has been accomplished with paddle-wheel type mixers or blenders. The traditional mixing machine comprises a barrel-like enclosure that is laid horizontally with a paddle shaft extending horizontally through the enclosure. An array of mixing paddles extend generally radially outward from the shaft, in the enclosure, and rotate with the shaft to mix selected ingredients that are placed in the enclosure. These traditional mixing machines are, however, quite slow. They also fail to sift the ingredients, thus requiring an additional processing step with additional equipment to break up clumps of material, or sift the mixture. Further, it is inherent in the traditional paddle type mixer that the mixing process occurs on a large scale. That is to say that the batch of mixture may have the desired ratios of the selected ingredients, but any given, small sample of the mixture may not. The resulting mixture may not be homogenous. 
     One may, then, realize a need for equipment that provides high speed mixing and sifting of ingredients, either wet or dry, to quickly provide a homogenous blend. 
     BRIEF SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides a material processor having an enclosure with an ingress to receive material into the enclosure, and a discharge to remove material from the enclosure. A spindle is located in the enclosure, has a longitudinal spindle axis, and is rotatable about the spindle axis. A drive is operatively connected with the spindle to rotate the spindle about the spindle axis. A centrifugal sieve is located in the enclosure and coupled with the spindle. The ingress feeds material into the sieve. A conveyor is connected with the discharge to transfer material from the enclosure. The conveyor further has a generally cylindrical tube with a tube diameter, two opposing ends, and a tube axis extending through the ends. A helical blade extends along the tube axis between the two ends and is rotated about the tube axis. 
     More particularly, the helical blade may have a series of blade tips that are spaced along the tube axis. Adjacent blade tips may be spaced apart by a distance that is less than or equal to about one half the tube diameter. Further, the helical blade is rotated at high speed, more specifically, between about 600 to about 1500 rpm. In another aspect of the invention, a volumetric ratio of material conveyed in the conveyor as compared to the internal volume of the conveyor is between about ten to about twenty percent. 
     Additionally, the tube may include first and second tube sections, or more, that are coupled together with a clamp ring. The first section may have a male end with a male flange, while the second section may have a female end with a corresponding female flange. The male and female ends and flanges abut one another to define a generally truncated V-shaped ridge that extends outward from the tube with opposing, inclined surfaces. The clamp ring overlays and presses inward upon the inclined surfaces to press the male and female flanges and ends together. 
     These and other features, objects, and benefits of the invention will be recognized by one having ordinary skill in the art and by those who practice the invention, from the specification, the claims, and the drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a front perspective view of a processor according to the invention; 
     FIG. 2 is a top plan view thereof; 
     FIG. 3 is a front elevational view thereof; 
     FIG. 4 is a right side elevational view thereof; 
     FIG. 5 is an exploded, side elevational view of the spiral elevator thereof; 
     FIG. 6 is a top plan view thereof; 
     FIG. 7 is a fragmentary cross-sectional view along section line VII—VII of FIG. 4; 
     FIG. 8 is an exploded view of the internal assembly of the processor; 
     FIG. 9 is a top plan view along sight line IX—IX of FIG. 8; 
     FIG. 10 is a top plan view along sight line X—X of FIG. 8; 
     FIG. 11 shows assembly of three elevator spiral sections; 
     FIG. 12 is an exploded, fragmentary, cross-sectional view along section line XII—XII of FIG. 5; 
     FIG. 13 is the view of FIG. 12, in an alternative, shorter, configuration wherein the bearing journal is not used, and not showing the spiral sections; 
     FIG. 14 is a cross-sectional view along section line VII—VII of FIG. 15; 
     FIG. 15 is the view of FIG. 2 with the loading hopper and spiral elevator extensions removed; 
     FIG. 16 is a bottom plan view thereof; 
     FIG. 17 is a right hand elevational view thereof; 
     FIG. 18 is a side elevational view of the loading hopper; 
     FIG. 19 is top plan view thereof; 
     FIG. 20 is a bottom plan view thereof; 
     FIG. 21 is another side elevational view thereof; 
     FIG. 22 is a top plan view of the sieve basket; 
     FIG. 23 is a cross-sectional view thereof, taken along section line A—A of FIG. 22; 
     FIG. 24 is a side elevational view of the sieve basket bottom panel; 
     FIG. 25 is a diametrical cross-sectional view of a tailing feed unit for the material processor; 
     FIG. 26 shows a side elevational view and a top plan view of a lower impeller of the material processor; 
     FIG. 27 shows a top plan view and a side elevational view of the hub of the sieve impeller; 
     FIG. 28 shows a plan view and an edge view of an elevator spiral blade; 
     FIG. 29 shows a plan view and an edge view of the donut seal of the material processor. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A material processor, mixer, or sieve according to the invention is generally shown in the drawing figures and identified by the reference numeral  100 . The material processor  100  is suitable for a broad range of material mixing requirements, either wet or dry, including commercial baking mixing of food ingredients, and mixing of chemicals in production of plastic products, for example. Processor  100  has a base or frame  102  with an enclosure or tub  104  mounted on the frame. A drive spindle  106  is located in the tub  104  and a drive in the form of a motor  108 , for example, is connected to drive the spindle  106 . A centrifugal sieve, including a sieve basket  134  and sieve impeller  136 , discussed further below, is removably located in the tub  104  and a discharge chute  112  directs material from the tub to a conveyor or elevator  120 . 
     Any suitable structural materials may be used in the fabrication of the material processor  100  and its components. Such materials will typically include metals and plastics, for example. The specific materials used will depend upon a number of factors, including, but not limited to, the characteristics of the material being processed and the acceptable useful life of the material processor or component thereof, which results from the material chosen, as will be understood by one having ordinary skill in the art. The use of stainless steel to fabricate the material processor and its components has proven successful as a durable, sanitary, and stable material for many commercial material processing operations. 
     The frame  102  preferably has a box base with a length of about 36 to about 42 inches (914 mm to 1067 mm), a width of about 22 to about 26 inches (558 mm to 660 mm), and a height of about 7 inches (178 mm) for general commercial applications. The tub  104  is a tubular member that is generally centered in the width of the base, is about 15 to about 20 inches (381 mm to 508 mm) tall, has an about 20 to about 24 inches (508 mm to 610 mm) inside diameter, and is formed of stainless steel. A loading hopper  122  is positioned on top of the tub  104  to provide an ingress to receive material into the tube  104 . The hopper is conveniently configured generally as a conic frustum. As is specifically shown in the drawing figures, the loading hopper  122  may have a flattened side to provide clearance for the conveyor or elevator  120 . 
     The drive spindle  106  is generally centered in the tub  104  and is connected to operate the centrifugal sieve, described further below. The drive motor  108  is mounted to the frame and connected by pulleys and a drive belt, for example, or by other suitable power transmission arrangement, to the drive spindle  106 , as will be understood by one having ordinary skill in the art. 
     The material processor  100  may be stationary, or may be provided with casters to transport the processor from one use location to another. Thus, the base or frame  102  may be provided with caster pads  126  (FIG.  16 ). The base  102  may also be provided with a handle  128  (FIGS. 3,  14 ,  15  and  17 ) for a user to push the processor  100  on the casters. The handle  128  also provides a convenient support frame for an electrical control box  130  to control operation of the processor. 
     The centrifugal sieve assembly includes a stationary sieve basket  134  and rotary sieve impeller  136 . A lower, discharge impeller  138  is provided below the sieve basket  134 . The discharge impeller  138 , sieve basket  134 , and sieve impeller  136  are concentrically mounted in the tub  104 , with the discharge impeller  138  and sieve impeller  136  being connected with the drive spindle  106  and the drive spindle passing through the bottom of the sieve basket. Depending upon the specific material processing utilized, an optional tailing feed unit  140  or deflector plate  142  may be stacked above the sieve impeller  136  on the drive spindle  106 . 
     The discharge chute  112  (FIG. 15) extends from the tub enclosure  104  to the spiral elevator  120  to remove material from the enclosure to the elevator. The processed material moves from the sieve basket  134  to the discharge impeller  138 , which sweeps the material out through the discharge chute  112  to the elevator  120 . 
     The spiral elevator  120  is a modular material conveyor comprising a series of pipe sections  146  and matching spiral sections  148 . Thus, the elevator  120  may be configured, and reconfigured, to a length, or height, that best suits the user&#39;s immediate needs. The pipe sections  146  are generally cylindrical lengths of tube that have a diameter, two opposing ends, and an axis extending through the two ends. Both the pipe sections  146  and matching spiral sections  148  are most preferably about 4 to about 8 inches (101 mm to 203 mm) in diameter and constructed of stainless steel. The spiral sections  148  have a spiral shaft  162  extending along the axis, and a helical blade  164  extending along the shaft  162 . The helical blade  164  extends generally radially outward from the shaft  162  and the axis. The shaft  162  will be configured with various lengths and diameters, according to the selected diameter of the pipe sections  146  and matching spiral sections  148 , as will be understood and appreciated by one having ordinary skill in the art. 
     Adjacent pipe sections  146  are mated with cooperating male  150  and female  152  flange ends and an overlaying, sanitary quick clamp ring  154  that cams two sections  146  together as the ring  154  is tightened around adjoining male  150  and female  152  flanges. When mated together, the cooperating male  150  and female  152  flanges define a generally truncated V-shaped ridge that extends outward from the outer surface of the pipe sections  146 , with opposing inclined surfaces. The clamp ring  154  overlays and presses inward upon the inclined surfaces, camming the male  150  and female  152  flanges toward one another. 
     Depending upon the length of the assembled spiral elevator  120 , an intermediate or steady bearing may need to be interposed in the spiral (FIG.  12 ), as will be understood by one having ordinary skill in the art. The steady bearing is preferably provided every about 36 to about 72 inches (914 mm to 1829 mm) of spiral length. The steady bearing is held in a bearing support  160  that is sandwiched between cooperating, adjacent female ends  152  of adjoining elevator spiral tube sections  146 . 
     According to common knowledge, conventional auger conveyors are known to be successfully used only when operated in a “full pack”, high density, high power, low rpm condition, as will be understood by one having ordinary skill in the art. Common knowledge further dictates that for an about 4 to about 8 inch (101 mm to 203 mm) diameter auger, the pitch of the auger blade must be at least one half the diameter for successful, efficient auger transport. Contrary to this conventional wisdom, the spiral conveyor  120  of the invention is a low density, low power, high speed elevator that conveys or transports product in a fluidized state, rather than in the conventional solid state of conventional auger conveyors. More particularly, the spiral  148  and the helical blade  164  are most preferably rotated at a speed in the range of about 800 to about 1,200 rpm. While the spiral rotational speed range may vary somewhat more and less than the range just stated, this is an optimal speed range that has been found to consistently attain fluidized transportation of the material being handled, with good result. The spiral rotational speed is important and depends upon various factors, such as the material formulation, density, granulation, and viscosity, for example. 
     The helical blade pitch is set at less than about one half the diameter of the spiral for the about 4 to about 8 inch (101 mm to 203 mm) diameter spiral  148 . With unacceptably low pitch and high rotational speed by conventional standards, the elevator  120  of the invention operates in a “fluidized” or “pneumatic pumping mode”, rather than the screw action mode of traditional auger conveyors that operate in a choke feed, non-emptying mode. Further, the spiral  148  of the invention operates with a volumetric material transfer density in the range of about 12 to about 15 percent, rather than the conventional auger conveyer preference to achieve a volumetric material transfer density approaching 100 percent. 
     The relatively high rotational speed of the spiral  148  and helical blade  164 , sets up a centrifugal action that pushes the material outward from the spiral shaft  162 , toward the elevator tubing, to create a “sealing” action at the tip of the spiral blade  164 . Thus, material is transported through the spiral elevator conveyor  120  generally on the tip of the spiral blade  164 . 
     It will be understood by those who practice the invention and by one having ordinary skill in the art, that various modifications and improvements to the embodiments discussed above, may be made without departing from the spirit of the disclosed concept. The scope of protection afforded is to be determined by the claims and by the breadth of interpretation allowed by law.