Patent Application
20160346745
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.
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.
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.
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
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
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.
