Patent Publication Number: US-2015072851-A1

Title: Centrifugal separator with circular rotor blades

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     In the US, this is a continuation-in-part of U.S. patent application Ser. No. 13/836,284, filed on 15 Mar. 2013, which was a nonprovisional patent application of U.S. Provisional Patent Application Ser. No. 61/615,541, filed 26 Mar. 2012, both of which are hereby incorporated herein by reference. 
     Priority of U.S. patent application Ser. No. 13/836,284, filed on 15 Mar. 2013, and U.S. Provisional Patent Application Ser. No. 61/615,541, filed 26 Mar. 2012, which are incorporated herein by reference, is hereby claimed. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to centrifugal separator systems. More particularly, the present invention relates to an improved centrifugal separator having rotor blades which are circular in cross-section. 
     2. General Background 
     In certain industries, centrifugal separators are used to separate liquids from solids in rather large volumes. For example, in the coal industry, often times coal is mined and is transported in a slurry form. In this form, the solid coal must be separated from the liquid portion of the slurry. This separation process is usually accomplished with the use of a centrifugal separator, where the slurry is passed through the separator and the solid coal is separated from the liquid. 
     One of the drawbacks of this type of separator system is that the solid coal, as it travels through the separator, must past through openings of a rotating rotor to reach its final destination. In the present state of the art, as the coal is traveling through the spaces between the rotor blades, the rotor is rotating at a certain speed, and the blades make contact with chunks of coal as it travels through. In the current state of the art, rotor blades are substantially flat or rectangular in shape, thereby having the walls of the blade at right angles to one another. Therefore, when the flat sides of the blade body make contact with chunks of coal, the contact often results in the coal being fractured into smaller pieces upon impact by the rotor blades. This direct contact between the coal and the blade also requires that the separator utilize additional energy to carry out its operation. These are not desired results. Therefore, there is a need in the industry for a separator which is less expensive to manufacture; which minimizes the fracturing of coal chunks into small pieces should contact be made by the circular rotating rotor blades on the coal, which results in the consumption of less energy to carry out the separation operation. 
     SUMMARY OF THE PRESENT INVENTION 
     The system of the present invention solves the problems in the art in a simple and straightforward manner. 
     What is provided is an improved centrifugal separator system and method for separating a solid portion from a liquid portion, of the type including a chute for introducing material into the separator; a screen rotated on a shaft for allowing a liquid portion of the material to flow through the screen but preventing solids from flowing through the screen; a space for allowing the solids to travel through the separator; a rotor portion, further comprising a plurality of blades radiating outward from a hub portion of the rotor to an outer ring portion of the rotor to define the traveling space for the solid material between the rotor blades; wherein each of the blades being circular in cross section along their length to minimize the impact on the solid material which makes contact with the rotating blades and reduces the fractures to the solid material, resulting in better product and a reduction in the energy required to power the separator. 
     It has been determined in testing that when the rotor blades are circular in cross-section, rather than having angular corners, impact with chunks of coal does not result in the coal being fractured into as many smaller pieces, which results in more coal pieces remaining intact, and because of the minimal contact, the system runs more efficiently, with a reduction in the amount of power to run the system. 
     Therefore, it is the principal object of the present invention to provide a separator system having an improved rotor with spokes or blades being circular in cross-section rather than flat, so as to reduce the fracturing of chunks of coal making contact with the blades as the coal travels through the rotor during the separation process. 
     It is the further principal object of the present invention to provide a centrifugal separator which includes a rotor having rotor blades which are circular in cross-section, thus reducing the impact of the blades on material, such as coal, traveling through the rotor, creating less wind from the rotor blades rotation, and also resulting in a more efficient, less energy intensive, system. 
     It is a further object of the present invention to provide a centrifugal separator which, because of the circular blades or spokes, is less expensive to manufacture, and which consumes less energy during operation. 
     Another object of the invention is to provide a centrifugal separator system wherein a wide range of solid material, other than coal, may be introduced for separation. 
     One embodiment of the system of the present invention is an improved centrifugal separator system for separating a solid portion from a liquid portion, of the type including a chute for introducing material into the separator; a screen rotated on a shaft for allowing a liquid portion of the material to flow through the screen but preventing solids from flowing through the screen; a space for allowing the solids to travel through the separator; a rotor portion, further comprising a plurality of blades radiating outward from a hub portion of the rotor to an outer ring portion of the rotor to define the traveling space for the solid material between the rotor blades; wherein each of the blades being circular in cross section along their length to minimize the impact on the solid material which makes contact with the rotating blades and reduces the fractures to the solid material, resulting in better product and a reduction in the energy required to power the separator. 
     In another embodiment of the system of the present invention, the material to be separated is coal suspended in a slurry or with other solids having a wet surface. 
     In another embodiment of the system of the present invention, the rotor and screen rotate between 200 and 2000 revolutions per minute (“RPM”) (3.34 to 33.34 hertz). 
     In another embodiment of the system of the present invention, the separator utilizes less energy due to the reduction of impact between the solid material and the circular wall of the rotor blades. 
     In another embodiment of the system of the present invention, the blades of the rotor radiate at a right angle from a hub portion of the rotor to an outer ring portion of the rotor to define the traveling space for the solid material between the rotor blades. 
     In another embodiment of the system of the present invention, the blades of the rotor radiate at an oblique angle from a hub portion of the rotor to an outer ring portion of the rotor to define the traveling space for the solid material between the rotor blades. 
     In another embodiment of the system of the present invention the material may comprise any material that could be separated from a liquid, such as various minerals, oil field cuttings and other types of solids. 
     In one embodiment of the method of the present invention, the method comprises separating solid coal from a liquid portion in a slurry, comprising the following steps: providing a centrifugal separator; introducing the coal slurry into the separator; routing the slurry to a rotating screen in the separator allowing the liquid portion of the material to flow through the screen but preventing the solid coal from flowing through the screen; providing a rotor portion, which further comprises a plurality of spaced apart blades, each of the blades being circular in cross section along their length; and flowing the solid coal through the spaces between the blades of the rotating rotor in the separator, so that the circular walls of the blades minimize the impact on the solid coal which makes contact with the rotating blades to reduce or eliminate fracturing to the pieces of solid coal. 
     In another embodiment of the method of the present invention, the rotor and screen are rotating at approximately 200 to 1300 RPM (3.34 to 21.67 hertz). 
     In another embodiment of the method of the present invention the blades being circular in cross section results in the utilization of less energy due to the reduction of impact between the solid coal and the circular wall of the rotor blades. 
     In another embodiment of the method of the present invention the material to be separated may be solid coal having moisture on its surface or the material may comprise any material that could be separated from a liquid, such as various minerals, oil field cuttings and other types of solids. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
         FIG. 1  illustrates in cross-section the centrifugal separator of the present invention with the improved rotor mounted thereon; 
         FIGS. 2A through 2E  illustrate various views of a first embodiment of the improved rotor blade with the blades or spokes extending outward from the hub of the rotor at a right angle from the hub wall; 
         FIGS. 3A through 3E  illustrate various views of a second embodiment of the improved rotor blade with the blades or spokes extending outward from the hub of the rotor at less than a right angle from the hub wall; 
         FIG. 4  illustrates a cross-section view of the blade of the rotor of the present invention; and 
         FIGS. 5A and 5B  illustrate views of the spokes radiating out from the hub of the rotor with no ring engaging the spokes at their terminal ends. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIGS. 1 through 5B  illustrate a preferred embodiment of the system of the present invention designated generally by the numeral  10 . Before describing the nature of the present invention, it should be made clear that centrifugal separator  10  as seen and described is similar in most respects to centrifugal separators found in the art, for example, in U.S. Pat. No. 5,720,879, owned by Elgin National Industries, Inc. The nature of the present invention over the prior is discussed below. 
     In  FIG. 1 , there is illustrated the preferred embodiment of the centrifugal separator  10  of the present invention. Separator  10  includes a hopper  12  into which the material (slurry  20 ) to be separated enters the separator  10 . For purposes of this application, the material will be described as coal in a slurry form, as an example, although other types of material may be subject to separation. An example of other material that may be introduced into hopper  12  is solid coal having a wet surface. Additionally, the material entering through hopper  12  may comprise any material that could be separated from a liquid, such as various minerals, oil field cuttings and other types of solids. 
     During operation separator  10  further provides a screen  14  at the lower end of the hopper  12  through which the liquid portion (arrow  16 ) will travel through to be routed to its final destination. Screen  14  will be rotating on outer shaft  30 . The solid portion (arrow  22 ) of the slurry  20  will be forced to travel through the circular space  26  along the outer wall  28  of the screen  14 , and reach the rear of screen  14  where there is mounted a rotor  40 , also rotating on outer shaft  30 . The rotor  40  is constructed, as seen in  FIGS. 2A-2E , with a central hub portion  42  and a plurality of spaced apart spokes or blades  44  radiating out from hub  42  to an outer ring  45  where the distal ends  46  of each spoke are mounted. There is defined a space  48  between blades  44 , the function of which will be described further. As in all separators, the construction of hub  42 , as defined so far, is quite typical in centrifugal separators. 
       FIGS. 2A through 4  define the improvements of the present invention over the prior art. As illustrated, each of the spokes or blades  44  are circular in cross-section, as seen in cross section view in  FIG. 4 , where there is defined a circular wall  50 , which, by its construction, has no right angular corners as seen in the prior art with flat blade construction. Arrow  60  in  FIG. 4  illustrates the path of the coal as it would be traveling through the spaces  48  between each of the blades  44 , without contacting the blades  44 , while arrow  62  illustrates other pieces of coal making contact with the circular walls  50  of blades  44 . 
     The circular wall construction of the blades  44  is critical, since in operation, the coal must travel through each of the spaces  48  between the spokes or blades  44 , while the rotor  40  is rotating at approximately 200 to 2000 RPM (3.34 to 33.34 hertz), to reach its final destination. (The optimum speed would be approximately 600 RPM (10 hertz)). In doing so, it is inevitable that the rotating rotor blades  44  will make direct contact with chunks of coal during their travel through the spaces  48  of rotor  40 . The circular wall  50  of each spoke  44  has been found to reduce significantly the impact that the circular spokes  44  have on the coal chunks as compared to the flat spokes of the prior art. A significantly less amount of coal is fractured, which results in a coal product that is not broken into small pieces. Further, because the impact on the coal is less with the circular blades  44 , the separator requires less energy to run during the separation process. It should be noted that  FIGS. 2A-2E  illustrate the spokes  44  emanating from the wall  43  of hub portion  42  at a right angle from wall  43 , while  FIGS. 3A-3E  illustrate the spokes  44  emanating at an angle less than a right angle from wall  43  of hub portion  42 . These two designs are being experimented to determine the most efficient design to utilize to reach the goals of reducing the impact on the coal and saving energy. 
       FIGS. 5A and 5B  illustrate another embodiment of the rotor  40  from which the spokes  44  radiate outward. As illustrated in  FIG. 5A , the spokes  44  are radiating outward at an oblique angle from the rotor hub portion  42 , while in  FIG. 5B  the spokes  44  radiate outward at a right angle from the rotor hub portion  42 . In both views, there is no outer ring  45  which the ends of the rotors attach to as in earlier embodiments. There is positioned a post, peg or stud  70  at the end of each spoke  44 , as illustrated, with the posts  70  positioned preferably about 1 inch (2.54 cm) from the end of each spoke  44 . Posts, pegs or studs  70  help hold the support basket in place. 
     The following is a list of parts and materials suitable for use in the present invention: 
     
       
         
           
               
            
               
                   
               
               
                 PARTS LIST 
               
            
           
           
               
               
            
               
                 Parts Number 
                 Description 
               
               
                   
               
               
                 10 
                 centrifugal separator 
               
               
                 12 
                 hopper 
               
               
                 14 
                 screen 
               
               
                 16 
                 arrow 
               
               
                 20 
                 slurry 
               
               
                 22 
                 arrow 
               
               
                 26 
                 circular space 
               
               
                 28 
                 outer wall 
               
               
                 30 
                 outer shaft 
               
               
                 40 
                 rotor 
               
               
                 42 
                 hub portion 
               
               
                 43 
                 wall 
               
               
                 44 
                 spokes or blades 
               
               
                 45 
                 outer ring 
               
               
                 46 
                 distal end 
               
               
                 48 
                 space 
               
               
                 50 
                 circular wall 
               
               
                 60 
                 arrow 
               
               
                 62 
                 arrow 
               
               
                 70 
                 post/peg/stud 
               
               
                   
               
            
           
         
       
     
     All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. 
     The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.