Dual stage continuous mixing apparatus

• US 6,123,445 A
• Filed: 09/12/1997
• Issued: 09/26/2000
• Est. Priority Date: 09/16/1996
• Status: Expired due to Term

• Current Assignee: Frank Grassi, Theresa Grassi
• Original Assignee: Frank Grassi
• Inventors: Grassi, Frank
• Primary Examiner(s): Cooley, Charles E.
• Application Number:
  US09/213,000
• Time in Patent Office: 1,110 Days
• Field of Search: 366/337, 366/28, 366/14, 366/15, 366/20, 366/21, 366/27, 366/30, 366/35, 366/38, 366/40, 366/50, 366/52, 366/64, 366/66, 366/67, 366/156.1, 366/156.2, 366/157.1, 366/157.2 , 366/158.4, 366/158.5, 366/168.1, 366/171.1, 366/172.2, 366/172.1, 366/174.1, 366/175.2, 366/181.5, 366/186, 366/193, 366/194-196, 366/302 , 366/307, 366/310, 366/320
• US Class Current: 366/20
• CPC Class Codes: B01F 27/2123 Shafts with both stirring means and feeding or discharging means
• CPC Class Codes: B01F 27/62 comprising liquid feeding, e.g. spraying means
• CPC Class Codes: B01F 27/70 with paddles, blades or arms
• CPC Class Codes: B01F 35/145 Washing or cleaning mixers not provided for in other groups in this subclass; Inhibiting build-up of material on machine parts using other means
• CPC Class Codes: B01F 35/71775 using helical screws
• CPC Class Codes: B28C 5/1292 with rotating stirring and feeding or discharging means fixed on the same axis, e.g. in an inclined container fed at its lower part

Abstract

A mixer for dry powder, very fine or granular materials and a liquid, e.g., mortar or cement and water, includes a dynamic input mixing stage, a static output mixing stage and a transition tube connecting the two stages in a manner which isolates the two stages from one another. The input mixing stage includes a hopper for receiving the mortar and a horizontal metering screw having a detachable mixing auger. The auger mixes the dry mortar, while the metering screw moves the mixed mortar through a discharge aperture in the hopper and into the transition tube. The metering screw extends into the transition tube for further displacing the dry mortar into the output mixing stage which includes a mixing tube having a fixed internal baffle assembly and an auger disposed along its length. A source of water is connected to the mixing tube for forming a mortar-water slurry. The auger is detachably connected to the metering screw for rotation therewith and acts as a pumping mechanism for discharging the slurry and preventing water from entering the transition tube. The baffle assembly includes an elongated axial rod removably inserted within the auger in the mixing tube and having a plurality of spaced baffles of alternating alignment disposed along its length for statically mixing the slurry. A pair of pivoting closure plates are disposed adjacent the aperture in the hopper for adjusting or shutting off the flow of mortar from the hopper to the transition tube.

Claims

1. A continuous mixing apparatus for particulate materials comprising:

a dynamic input mixing stage including a housing adapted to receive the particulate materials and first displacement means for moving the particulate materials toward and through an aperture in said housing;

a transition tube coupled to said housing adjacent the aperture therein for receiving the particulate materials upon discharge through the housing aperture by said first displacement means; and

a static output mixing stage coupled to said transition tube for receiving the particulate materials from said transition tube, said output mixing stage including a mixing tube coupled to a source of liquid for adding a liquid to the particulate materials in forming a slurry, second displacement means disposed in said mixing tube for displacing the particulate material and slurry along said mixing tube and discharging the slurry from the mixing tube, and a baffle assembly fixedly disposed within and along the length of said mixing tube for thoroughly mixing the particulate materials and the liquid in forming the slurry prior to discharge from said mixing tube wherein said transition tube and said mixing tube are coaxially aligned.

2. The apparatus of claim 1 wherein an upper portion of said housing is open to facilitate receiving the particulate materials and wherein said first displacement means includes a metering screw.

3. The apparatus of claim 2 wherein said metering screw extends through the aperture in said housing and into said transition tube for further moving the particulate materials to said output mixing stage.

4. The apparatus of claim 3 further comprising adjustable closure means disposed adjacent the aperture in said housing and in closely spaced relation about said metering screw for adjusting or terminating the flow of particulate material from said housing to said transition tube.

5. The apparatus of claim 4 wherein said closure means includes at least one plate movable between a first closed position over the aperture in said housing and a second opened position removed from said aperture.

6. The apparatus of claim 5 wherein said closure means includes first and second plates pivotally coupled to said housing and having respective cut-out portions for receiving said metering, screw when said plates are closed to allow for continued operation of said metering screw when said plates are closed for discharging the particulate materials from said transition tube into said output mixing stage.

7. The apparatus of claim 6 further comprising flow reversing means disposed in said hopper for mixing the particulate materials and for displacing the particulate materials away from the aperture in said hopper when the aperture is closed by said first and second plates.

8. The apparatus of claim 7 wherein said flow reversing means includes a first agitator coupled to said metering screw for rotation therewith for mixing the particulate materials and for directing the particulate materials away from the aperture in said housing for preventing build-up of the particulate materials against said first and second plates when said plates are closed.

9. The apparatus of claim 8 further comprising a second agitator coupled to said metering screw for rotation therewith for mixing the particulate materials and for directing the particulate materials toward the aperture in said housing for removal from the housing through the aperture therein by said metering screw.

10. The apparatus of claim 9 wherein said first agitator includes an outer helix member and said second agitator includes an inner helix member, and wherein said outer and inner helix members are concentrically disposed about and aligned with said metering screw.

11. The apparatus of claim 10 wherein said housing includes an inner trough-forming wall extending the length of said housing and disposed in closely spaced relation to said outer helix member.

12. The apparatus of claim 1 further comprising detachable connecting means for removably coupling said transition tube to said housing.

13. The apparatus of claim 1 further comprising drive means for rotationally displacing said first displacement means.

14. The apparatus of claim 13 wherein said drive means includes a gas, hydraulic or electric motor.

15. The apparatus of claim 1 wherein said first displacement means includes a metering screw and wherein said the second displacement means includes an auger screw detachably coupled to said metering screw.

16. The apparatus of claim 15 wherein said auger screw includes an outer continuous helical coil disposed in close proximity to an inner surface of said mixing tube and an inner helical wall coupled to and extending inwardly from said outer helical coil to a position in closely spaced relation from an end of said metering screw.

17. The apparatus of claim 16 further comprising detachable means for removably coupling said auger screw to said metering screw.

18. The apparatus of claim 17 wherein said baffle assembly is removably disposed within said mixing tube and extends along the length thereof for mixing the particulate materials with the liquid.

19. The apparatus of claim 18 wherein said baffle assembly includes an axial rod coupled to a plurality of angled baffle plates arranged in a spaced manner along the length of said rod for alternately deflecting the slurry in first and second opposed directions generally transverse to said axial rod.

20. The apparatus of claim 19 wherein said axial rod and baffle plates are removably inserted in said mixing tube and are disposed within the outer helical coil of said auger screw.

21. A continuous mixing apparatus for granular materials comprising:

a dynamic input mixing stage including a housing with a metering screw for mixing the granular materials and discharging the granular materials through an aperture in said housing;

a static output mixing stage coupled to said housing adjacent said aperture therein for receiving the granular materials and mixing the granular materials with a liquid in forming a slurry;

adjustable closure means disposed adjacent the aperture in said housing for varying or blocking the flow of granular materials from said input mixing stage to said output mixing stage when closed; and

flow reversing means disposed in said housing for mixing the granular materials and displacing the granular materials away from said closure means when said closure means blocks the flow of granular materials in preventing dense packing of granular materials against said closure means when said closure means is closed.

22. The apparatus of claim 21 wherein said closure means includes a plurality of plates each movable between a first closed position over the aperture in said housing and a second open position removed from said aperture.

23. The apparatus of claim 22 wherein said closure means includes first and second generally flat plates pivotally coupled to said housing and movable between said first closed and said second open positions.

24. The apparatus of claim 23 wherein each plate includes a respective handle for manually moving said plates between said first closed and said second open positions.

25. The apparatus of claim 24 wherein each plate further includes a respective recessed portion positioned adjacent said metering screw when said plates are in said first closed position to permit continued operation of said metering screw when said plates are closed.

26. The apparatus of claim 22 wherein said flow reversing means includes a first agitator coupled to said metering screw for rotation therewith for mixing the granular materials and directing the granular materials away from the aperture in said housing for preventing build-up of the granular materials against said plates when said plates are closed.

27. The apparatus of claim 26 further comprising a second agitator coupled to said metering screw for rotation therewith for mixing the granular materials and directing the granular materials toward the aperture in said housing for removal from the housing through the aperture therein by said metering screw.

28. The apparatus of claim 27 wherein said first agitator includes an outer helix member and said second agitator includes an inner helix member, and wherein said outer and inner helix members are concentrically disposed about and aligned with said metering screw.

29. The apparatus of claim 28 wherein said housing includes an inner trough-forming wall extending the length of said housing and disposed in closely spaced relation to said outer helix member.

30. The apparatus of claim 29 further comprising detachable connecting means for removably coupling said static output mixing stage to said dynamic input mixing stage.

31. The apparatus of claim 30 further comprising drive means for rotationally displacing said metering screw.

32. The apparatus of claim 31 wherein said drive means includes a gas, hydraulic or electric motor.

33. Apparatus for continuously mixing particulate material with a liquid, said apparatus comprising:

an elongated, linear tube having a longitudinal axis and first and second opposed ends and an intermediate portion disposed therebetween, wherein particulate material is introduced in said tube at the first end thereof;

a source of liquid coupled to the intermediate portion of said tube for adding liquid to the particulate material in forming a particulate-liquid slurry;

displacement means for moving the particulate material from the first end to the intermediate portion of the tube and for moving the slurry from the intermediate portion to the second end of said tube for discharge therefrom; and

mixing means fixedly disposed in said tube for deflecting the particulate material and the slurry in alternating first and second opposed directions generally transverse to the longitudinal axis of said tube to provide a homogeneous mixture in the slurry discharged from said tube wherein said mixing means includes a baffle assembly removably disposed within said tube and extending along the length thereof for mixing the particulate material with the liquid.

34. The apparatus of claim 33 wherein said displacement means includes an auger screw coupled to a drive source for rotationally displacing said auger screw.

35. The apparatus of claim 34 wherein said drive source includes a rotating shaft and said auger screw includes an outer continuous helical coil disposed in close proximity to a n inner surface of said tube and an inner helical wall coupled to and extending inwardly from said outer helical coil to a position in closely spaced relation from an end of said rotating shaft.

36. The apparatus of claim 35 further comprising detachable coupling means for removably coupling said auger screw to said rotating shaft.

37. The apparatus of claim 35 wherein said inner helical wall is disposed in the first end of said tube.

38. The apparatus of claim 37 wherein said source of liquid is coupled to said tube at a location intermediate said inner helical wall of said auger screw and the second end of said tube.

39. The apparatus of claim 33 wherein said baffle assembly includes an axial rod coupled to a plurality of angled baffle plates arranged in a spaced manner along the length of said rod for alternately deflecting the particulate-liquid slurry in first and second opposed directions generally transverse to said axial rod.

40. The apparatus of claim 39 wherein said axial rod and baffle plates are removably inserted in said mixing tube and are disposed within the outer helical coil of said auger screw.