Patent Publication Number: US-9833755-B2

Title: System for mixing/blending fine bulk materials

Description:
This invention relates to a system for mixing/blending fine bulk materials and more particularly to such a system for recycling such material in a manner including infusing, impelling and accommodating the flow of such material with a fluid. 
     BACKGROUND OF THE INVENTION 
     In the prior art, there exist a number of systems for mixing or blending fine bulk materials which generally include a vessel for holding such material and means for conveying such material from a lower end of such vessel to an upper end thereof, resulting in a mixing or blending thereof. Such systems, however, have been found not to be highly effective in sufficiently and economically functioning to mix and/or blend such materials. Accordingly, it is the principal object of the present invention to provide a system for mixing or blending a body of fine bulk material which is highly effective in reducing the back pressure on such body of material thereby facilitating the recirculation of such material. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the deficiencies of the prior art by providing a system for mixing a fine hulk material generally including means for containing a fine bulk material, means for recirculating such material from a lower end of the containing means to an upper end thereof, means disposed in an upper portion of the lower end of the containing means for injecting a flow of fluid into a portion of such material under pressure sufficient to penetrate and fluidize such material therein, means disposed in a lower portion of the lower end of such containing means for injecting a flow of fluid into a portion of the material therein under a pressure sufficient to fluidize material therein and means for injecting a fluid under pressure into the recirculating means for impelling fluidized material received therein, through such recirculating means. In the preferred embodiment of the invention, the means for containing the fine bulk material is provided with a frusto-conically configured lower end funned of an impermeable material, a frusto-conically configured component formed of a permeable material disposed within and coaxially relative to and spaced from the frusto-conically lower end of such containing means, having upper, lower and intermediate annular components providing upper and lower annular chambers therebetween, means for injecting a fluid under pressure into such upper chamber sufficient to penetrate the permeable frusto-conically configured component and fluidize material disposed therein, and means for injecting a fluid under pressure into the lower chamber sufficient to penetrate the permeable frusto-conically configured component and fluidize material disposed therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevational view of a system embodying the present invention, having portions thereof broken away displaying interior constructions thereof; 
         FIG. 2  is an enlarged, fractional view of a portion of the system identified in  FIG. 1 ; 
         FIG. 3  is an elevational view of a spool assembly forming a component of the lower end of the system shown in  FIG. 1 ; 
         FIG. 4  is a top view of the spool assembly shown in  FIG. 3 ; and 
         FIG. 5  is an enlarged cross-sectional view of the assembly shown in  FIG. 4  taken along line  5 - 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION 
     Referring to the drawings, there is illustrated an embodiment of the invention which generally consists of a vertically disposed vessel  10  mounted on a support structure  11 , a spool assembly  12  mounted on the lower end of vessel  10  and a recycling assembly  13  intercommunicating the spool assembly with an upper portion of the vessel. Vessel  10  includes an upper cylindrical portion  14  and a depending frusto-conically configured portion  15 . The lower end of cylindrical portion  14  is provided an annular flange  16  for seating the vessel on support structure  11 , and a cover plate  17  is provided at the upper end thereof which may be removed to load a fine bulk material to be mixed or blended. As best shown in  FIG. 2 , component  15  includes an outer, frusto-conically configured member  18  formed of an impermeable material, an inner frusto-conically configured member  19  formed of a permeable material disposed coaxially relative to and spaced inwardly from member  18 , annular end walls (not shown) disposed between the upper and lower portions of members  18  and  19  and one or more annular wall member  20  disposed in the space between members  19  and  20  and cooperating with the annular end walls thereof to provide upper and lower annular chambers  21  and  22  communicable with inner frusto-conically configured chamber  23  through the interstices of inner, permeable frusto-conically configured member  19 , Fluid under pressure may be supplied to annular chamber  21  and through member  19  into the upper end of chamber  23 , by means of a fluid line  24  connected to a source of fluid under pressure and provided with a valve  25 , and fluid under pressure may be supplied to annular chamber  22  and through permeable member  19  into the lower end of chamber  23  by means of a fluid line  26  connected to a source of fluid under pressure and provided with a control valve  27 . Frusto-conically configured member  19  may be formed of a material manufactured for and sold by The Young industries, Inc, of Muncy, Pa. under the trademark TRANSFLOW. 
     Spool assembly  12  includes a vertically disposed cylindrical member  30  provided with upper and lower annular connecting flanges  31  and  32 , a radially disposed conduit  33  mounted on member  30  and communicating at one end thereof with the interior of cylinder  30 , and provided with an annular connecting flange  34  at a opposite end thereof. Mounted on the opposite side of cylindrical member  30  is a radially disposed nozzle  35  aligned coaxially with cylindrical member  33 . Disposed within cylindrical member  30 , coaxially and spaced thereform is a conduit  36  formed of a permeable material, having openings disposed axially with respect to conduit  33  and nozzle  35 . Similarly, conduit  33  is provided with a cylindrical member  37  formed of a permeable material disposed axially and spaced from conduit  33 , interconnecting permeable member  36  and flange  34 . 
     Disposed between the lower end of frusto-conically configured component  15  of the vessel and cylindrical member  30  is a valve  38  which may be closed during loading of material material to be mixed or blended into the vessel, and opened to allow the flow of fluidized material from component  15  through the spool assembly. Provided on the lower end of cylindrical member  30  is a valve  39  adapted to be closed during recirculation of the material in the vessel for blending and opened following blending for discharging. 
     Fluid under pressure is provided to the annular spacing between cylindrical member  30  and permeable cylindrical member  36  by means of a conduit  40  provided with a valve  41 , interconnecting a source of fluid under pressure and inlets  41  and  42  as shown in  FIG. 3 . Such fluid under pressure penetrates permeable member  36  to form a boundary layer along the inner side of permeable member  36  thus minimizing contact of the fluidized material flowing through conduit  30  with such conduit and enhancing the flow therethrough. Similarly, conduit  43  provided with a valve  44 , interconnecting a source of fluid under pressure and inlet  47 , provides a fluid under pressure to the annular spacing between cylindrical members  33  and  37  and through permeable member  37  to form a boundary layer of fluid along the inner side of permeable member  37 , minimizing fluidized material contact with permeable member  37  and correspondingly enhancing the flow of fluidized material therethrough. 
     Recirculating assembly  13  includes a vertical section  50  a lower elbow section  51  interconnecting a lower end of section  50  and conduit  33 , and a upper elbow section  52  interconnecting an upper end of vertical section  50  and a chute  53  mounted on the wall of cylindrical section  14 , extending through an opening in such a wall section and connected to a elbow section  52 , and having a section disposed within cylindrical portion  14  and communicating with the interior thereof. Each of components  50 ,  51  and  52  is formed of an outer conduit formed of an impermeable material and an inner conduit formed of a permeable material spaced from such outer conduit, providing a passageway from the spool assembly to the upper end of the vessel. Means are provided for supplying fluid under pressure to the spacing between the inner and outer conduits of assembly  13 , which is caused to penetrate the permeable inner conduits thereof, forming a boundary layer of fluid along such passageway, accommodating the flow of fluidized material therethrough. Nozzles  54  and  55  connected to a source of fluid under pressure, arc provided on elbow sections  51  and  52 , respectively, for injecting fluid under pressure for impelling fluidized material through the passageway therein, into the upper end of the vessel. 
     In the use of the system as described to mix or blend a batch of fine bulk material, valves  38  and  39  are closed, cover plate  17  is removed and the material is loaded into the upper end of vessel  10 , With such material thus having been loaded and cover plate  17  closed, valve  38  is opened to provide material access through the spool and recirculating assemblies, and suitable valves are opened to provide a boundary layer of fluid along the passageway provided through the spool and recirculating assemblies. Fluid under pressure is then provided through conduit  24 , annular chamber  21  and through permeable component  19  to fluidize material in the upper conical portion of space  23  of the vessel. Simultaneously, fluid under pressure is provided through conduit  26 , annular chamber  22  and through permeable component  19  to fluidize material in the lower conical space  23  of the vessel. Fluid under pressure injected through nozzles  35 ,  54  and  55  further function to impel fluidized material received through the lower end of the vessel, through the material passageway provided by the spool and recirculating assemblies, to and into the upper portion of the vessel. The flow of such fluidized material is accommodated by the fluid boundary provided in the passageway through the spool and recirculating assemblies. Such recirculation of material is repeated to provide the desired mixing or blending of the material whereupon the injection of fluid under pressure is discontinued, valve  39  is opened and the mixed or blended material is permitted to gravity flow out of the vessel into a container or through a conveying conduit. 
     Typically, in seeking to mix or blend a tine bulk material deposited in a vessel by recirculation of such material, such recirculation invariably is precluded by the fact that the back pressure of the conveying system is greater than the head pressure on the deposited material. Such impediment is overcome in the present invention by fluidizing the material in the upper and lower segments of the inner frusto-conically configured component formed of a permeable material, causing it to be drawn into and through the spool assembly and to be impelled through the passageway provided by the spool and recirculating assemblies, lined with a boundary layer of fluid reducing friction and correspondingly enhancing the flow of fluidized material to the upper end of the vessel 
     From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention, which come within the province of those persons having ordinary skill in the art to which the aforementioned invention pertains. However, it is intended that all such variations not departing from the spirit of the invention be considered as within the scope thereof as limited solely by the appended claims.