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Title:
MIXER SYSTEM
Document Type and Number:
WIPO Patent Application WO/2013/134858
Kind Code:
A1
Abstract:
A mixer system for mixing together four preselected components, i.e., plant substrate, absorbent material, urea, and lactic acid, to produce a feed product. The mixer system includes a mixer subsystem having a mixer assembly including a mixer body defining a cavity therein in which the components are mixed together by one or more mixing elements. The components are released into the cavity at predetermined locations on the mixer body to permit interaction of the components to result in the feed product being substantially homogeneous.

Inventors:
NIXON, Anthony (69 Doncaster Avenue, London, Ontario N6G 2A4, CA)
Application Number:
CA2013/000224
Publication Date:
September 19, 2013
Filing Date:
March 12, 2013
Export Citation:
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Assignee:
NIXON, Anthony (69 Doncaster Avenue, London, Ontario N6G 2A4, CA)
International Classes:
A23N17/00; A23K1/14; A23K1/16; A23K3/00
Foreign References:
DE10124113A12002-12-05
US6077546A2000-06-20
US4462693A1984-07-31
DE4325686A11995-02-02
GB2304056A1997-03-12
Attorney, Agent or Firm:
GOWLING LAFLEUR HENDERSON LLP (Suite 1020, 50 Queen Street NorthP.O. Box 224, Kitchener Ontario N2H 6M2, CA)
Download PDF:
Claims:
A mixer system for mixing preselected first, second, third, and fourth components together to produce a feed product, the mixer system comprising: a mixer subsystem comprising: a mixer assembly comprising: a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein; at least one mixing element mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end, to produce the feed product at the second end; a first reservoir for feeding the first component at a first predetermined flow rate into the cavity at a first location at a first preselected distance from the first end of the mixer body; a second reservoir for feeding the second component at a second predetermined flow rate into the cavity at a second location at a second preselected distance from the first end; a third reservoir for feeding the third component at a third predetermined flow rate into the cavity at a third location at a third preselected distance from the second location; a fourth reservoir for feeding the fourth component at a fourth predetermined flow rate into the cavity at a fourth location, the fourth location being located at a fourth preselected distance from the second location; and the first, second, third and fourth preselected distances being selected to permit the first and second components to be mixed together to form a substantially homogeneous premixture, prior to addition of the third and fourth components thereto, and to permit mixture of the third and fourth components with the premixture such that the feed product is substantially homogeneous when provided at the second end.

2. A mixer system according to claim 1 in which the first and second distances are substantially similar, and the third distance exceeds the second distance.

3. A mixer system according to claim 1 in which a difference between the fourth distance and the third distance is less than the third distance.

4. A mixer system according to claim 1 additionally comprising a packaging subsystem for packaging the feed product after the feed product exits the mixer assembly.

5. A mixer system according to claim 1 in which said at least one mixing element is rotatably mounted in the body.

6. A mixer system according to claim 1 in which the first and second components are a plant substrate material and an absorbent material respectively.

7. A mixer system according to claim 1 in which the third component is urea and the fourth component is a lactic acid bacteria.

8. A mixer system according to claim 1 in which the first component is an absorbent material, and the second component is a plant substrate material.

9. A mixer system according to claim 1 in which the third component is a lactic acid bacteria and the fourth component is urea.

10. A mixer system according to claim 1 in which the first, second, third, and fourth components are a plant substrate material, an absorbent material, urea, and a lactic acid bacteria respectively.

11. A mixer system according to claim 10 in which the mixer assembly additionally comprises at least one shredder positioned for shredding the plant substrate material.

12. A mixer system according to claim 10 in which the mixer assembly additionally comprises at least one shredder positioned for shredding the plant substrate material and the absorbent material.

13. A mixer system according to claim 12 in which said at least one mixing element mixes the plant substrate material, the absorbent material, the urea, and the lactic acid bacteria together in substantially anaerobic conditions.

14. A mixer system according to claim 13 in which the plant substrate material, the absorbent material, the urea, and the lactic acid bacteria are substantially homogenized by said at least one mixing element, such that the feed product provided at the second end is substantially homogeneous.

15. A mixer system according to claim 14 in which the plant substrate material is at least partially fermented by the lactic acid bacteria as the plant substrate material, the absorbent material, the urea, and the lactic acid bacteria are mixed together by said at least one mixing element.

16. A mixer system according to claim 1 in which: said at least one mixing element comprises at least two blade subassemblies at least partially positioned in the cavity, for mixing the components together to produce the feed product; the cavity being at least partially defined by at least one internal surface of the body comprising: a lower portion thereof at least partially defining respective spaces in which said at least two blade subassemblies are at least partially located; and an upper portion thereof at least partially spaced apart from said at least two blade subassemblies by a minimum preselected central distance for each said blade subassembly respectively to at least partially define an upper part of the cavity above said at least two blade subassemblies to facilitate mixing the components together.

17. A mixer system according to claim 16 in which the lower portion defines respective channels in which each of said at least two blade subassemblies is positioned, each said channel having a profile substantially parallel to an outer profile of each of said at least two blade subassemblies respectively.

18. A mixer system according to claim 17 in which the upper part of the cavity permits the components to be at least partially thrown therethrough from one of said at least two blade subassemblies to the other as the components are mixed by said at least two blade subassemblies.

19. A mixer system according to claim 1 additionally comprising a control subsystem for controlling movement of the components respectively into the cavity, to result in predetermined proportions of the respective components in the feed product.

20. A mixer assembly for mixing a plurality of preselected components together in predetermined proportions to provide a feed product, the mixer assembly comprising: a mixer body at least partially defining a cavity therein into which the materials are movable, the mixer body extending between first and second ends thereof; at least two blade subassemblies at least partially positioned in the cavity, for mixing the materials together to produce the animal feed product; the cavity being at least partially defined by an internal surface of the mixer body comprising: a lower portion at least partially defining respective channels in which said at least two blade subassemblies are located respectively; and an upper portion at least partially spaced apart from said at least two blade subassemblies by a minimum preselected central distance for each said blade subassembly respectively to at least partially define an upper part of the cavity above said at least two blade subassemblies to facilitate mixing the components together.

21. A mixer assembly according to claim 20 in which: the mixer body comprises: a first opening at a first location at a first preselected distance from the first end of the mixer body, through which a first component is flowable; a second opening at a second location at a second preselected distance from the first end of the mixer body, through which a second component is flowable; a third opening at a third location at a third preselected distance from the second location, through which a third component is flowable; a fourth opening at a fourth location at a fourth preselected distance from the second location, through which a fourth component is flowable; the first, second, third, and fourth preselected distances being selected to permit the first and second components to be mixed together to form a substantially homogeneous premixture; the fourth component being added to the premixture to ferment at least a portion of the first component; and said at least two blade subassemblies being formed to mix the premixture and the third and fourth components together such that the feed product is substantially homogeneous.

22. A mixer assembly according to claim 21 additionally comprising a shredder for shredding the first component, to facilitate the mixing of the first and second components into the substantially homogeneous premixture.

23. A method of mixing preselected first, second, third, and fourth components together to produce a feed product, the method comprising the steps of: (a) providing a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein;

(b) providing at least one mixing element mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end;

(c) directing the first component into the cavity at a first predetermined flow rate, at a first location at a first preselected distance from the first end of the body;

(d) directing the second component into the cavity at a second predetermined flow rate, at a second location at a second preselected distance from the first end of the body;

(e) mixing the first and second components together to provide a substantially homogeneous premixture while moving the first and second components in the downstream direction from the second location;

(f) directing the third component into the cavity at a third predetermined flow rate, at a third location at a third preselected distance from the second location;

(g) mixing the third component and the premixture together, to substantially evenly distribute the third component throughout the premixture;

(h) directing the fourth component into the cavity at a fourth predetermined flow rate, at a fourth location at a fourth preselected distance from the second location; and

(i) mixing the first, second, third, and fourth components together to homogenize the components, to produce the feed product therefrom.

A method according to claim 23 additionally comprising the following step, immediately flowing step (d) thereof:

(d.l) shredding the first and second components to a preselected maximum particle size.

25. A method according to claim 23 in which the first, second, third, and fourth components are a plant substrate material, an absorbent material, urea, and a lactic acid bacteria respectively.

26. A method according to claim 25 in which: the plant substrate comprises carbohydrates; the urea comprises non-protein nitrogen; in the presence of the urea, the lactic acid bacteria utilize at least a portion of the carbohydrates in the plant substrate material to convert the non-protein nitrogen to provide protein in the feed product.

27. A method according to claim 25 in which the plant substrate material, the absorbent material, the urea, and the lactic acid bacteria are mixed together in substantially anaerobic conditions.

28. A method according to claim 25 in which fermentation takes place as the plant substrate material, the absorbent material, the urea, and the lactic acid bacteria are mixed together to produce the feed product therefrom.

29. A mixer system for mixing preselected first, second, third, and fourth components together to produce a feed product, the mixer system comprising: a mixer subsystem comprising: a mixer assembly comprising: a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein; at least one mixing element mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end, to produce the feed product at the second end; a first reservoir for feeding the first component at a first predetermined flow rate into the cavity at a first location at a first preselected distance from the first end of the mixer body; a second reservoir for feeding the second component at a second predetermined flow rate into the cavity at the first location; a third reservoir for feeding the third component at a third predetermined flow rate into the cavity at a third location at a third preselected distance from the first location; a fourth reservoir for feeding the fourth component at a fourth predetermined flow rate into the cavity at a fourth location, the fourth location being located at a fourth preselected distance from the first location; and the first, third and fourth preselected distances being selected to permit the first and second components to be mixed together to form a substantially homogeneous premixture, prior to addition of the third and fourth components thereto, and to permit mixture of the third and fourth components with the premixture such that the feed product is substantially homogeneous when provided at the second end.

A method of mixing preselected first, second, third, and fourth components together to produce a feed product, the method comprising the steps of:

(a) providing a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein;

(b) providing at least one mixing element mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end;

(c) directing the first component into the cavity at a first predetermined flow rate, at a first location at a first preselected distance from the first end of the body; directing the second component into the cavity at a second predetermined flow rate, at the first location; mixing the first and second components together to provide a substantially homogeneous premixture while moving the first and second components in the downstream direction from the first location; directing the third component into the cavity at a third predetermined flow rate, at a third location at a third preselected distance from the first location; mixing the third component and the premixture together, to substantially evenly distribute the third component throughout the premixture; directing the fourth component into the cavity at a fourth predetermined flow rate, at a fourth location at a fourth preselected distance from the first location; and mixing the first, second, third, and fourth components together to homogenize the components, to produce the feed product therefrom.

Description:
MIXER SYSTEM

FIELD OF THE INVENTION

[0001 ] The present invention is a mixer system for mixing preselected components together to produce a feed product.

BACKGROUND OF THE INVENTION

[0002] As is well known in the art, significant amounts of waste plant materials are generated when plants are processed to produce foods. The waste plant materials may be, e.g., waste material resulting from processing vegetables and fruits, such as stems, leaves, peelings, cores, pulp and the like. In order to utilize the waste plant materials, various products, each including a certain proportion of the waste plant material, have been proposed. However, in the prior art, consistently achieving the required degree of mixing of the waste plant materials with other materials has proved to be challenging.

SUMMARY OF THE INVENTION

[0003] For the foregoing reasons, there is a need for a mixer system that overcomes or mitigates one or more of the disadvantages of the prior art.

[0004] In its broad aspect, the invention provides a mixer system for mixing preselected first, second, third, and fourth components together to produce a feed product. The mixer system includes a mixer subsystem having a mixer assembly including a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein, and one or more mixing elements mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end, to produce the feed product at the second end. The mixer subsystem also includes: a first reservoir for feeding the first component at a first predetermined flow rate into the cavity at a first location at a first preselected distance from the first end of the mixer body; a second reservoir for feeding the second component at a second predetermined flow rate into the cavity at a second location at a second preselected distance from the first end; a third reservoir for feeding the third component at a third predetermined flow rate into the cavity at a third location at a third preselected distance from the second location; and a fourth reservoir for feeding the fourth component at a fourth predetermined flow rate into the cavity at a fourth location, the fourth location being located at a fourth preselected distance from the second location.

[0005] The first, second, third and fourth preselected distances are selected to permit the first and second components to be mixed together to form a substantially homogeneous premixture, prior to addition of the third and fourth components thereto, and to permit mixture of the third and fourth components with the premixture such that the feed product is substantially homogeneous when provided at the second end.

[0006] In another aspect, the first and second distances are substantially similar, and the third distance exceeds the second distance.

[0007] In another aspect, the mixer system additionally includes a packaging subsystem for packaging the feed product after the feed product exits the mixer assembly.

[0008] In yet another aspect, the first, second, third, and fourth components are a plant substrate material, an absorbent material, urea, and lactic acid respectively.

[0009] In another aspect, the invention provides a control subsystem for controlling movement of the components respectively into the cavity.

[0010] In another of its aspects, the invention provides a method of mixing preselected first, second, third, and fourth components together to produce a feed product. The method includes the steps of providing a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein, and providing at least one mixing element mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end. The first component is directed into the cavity at a first predetermined flow rate, at a first location at a first preselected distance from the first end of the body. The second component is directed into the cavity at a second predetermined flow rate, at a second location at a second preselected distance from the first end of the body. The first and second components are mixed together to provide a substantially homogeneous premixture while moving the first and second components in the downstream direction from the second location. The third component is directed into the cavity at a third predetermined flow rate, at a third location at a third preselected distance from the second location. The third component and the premixture are mixed together, to substantially evenly distribute the third component throughout the premixture. The fourth component is directed into the cavity at a fourth predetermined flow rate, at a fourth location at a fourth preselected distance from the second location. The first, second, third, and fourth components are mixed together to homogenize the components, to produce the feed product therefrom.

[001 1] In yet another of its aspects, the invention provides a mixer system for mixing preselected first, second, third, and fourth components together to produce a feed product. The mixer system includes a mixer subsystem with a mixer assembly including a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein, and one or more mixing elements mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end, to produce the feed product at the second end. The mixer subsystem also includes: a first reservoir for feeding the first component at a first predetermined flow rate into the cavity at a first location at a first preselected distance from the first end of the mixer body; a second reservoir for feeding the second component at a second predetermined flow rate into the cavity at the first location; a third reservoir for feeding the third component at a third predetermined flow rate into the cavity at a third location at a third preselected distance from the first location; and a fourth reservoir for feeding the fourth component at a fourth predetermined flow rate into the cavity at a fourth location, the fourth location being located at a fourth preselected distance from the first location.

[0012] The first, third and fourth preselected distances are selected to permit the first and second components to be mixed together to form a substantially homogeneous premixture, prior to addition of the third and fourth components thereto, and to permit mixture of the third and fourth components with the premixture such that the feed product is substantially homogeneous when provided at the second end.

[0013] In another of its aspects, the invention provides a method of mixing preselected first, second, third, and fourth components together to produce a feed product. The method includes the steps of providing a mixer body extending between first and second ends thereof, the mixer body defining a cavity therein, and providing at least one mixing element mounted in the mixer body for mixing the first, second, third, and fourth components together in the cavity, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end. The first component is directed into the cavity at a first predetermined flow rate, at a first location at a first preselected distance from the first end of the body, and the second component is also directed into the cavity at a second predetermined flow rate, at the first location. The first and second components are mixed together to provide a substantially homogeneous premixture while moving the first and second components in the downstream direction from the first location. The third component is directed into the cavity at a third predetermined flow rate, at a third location at a third preselected distance from the first location. The third component and the premixture are mixed together, to substantially evenly distribute the third component throughout the premixture. The fourth component is directed into the cavity at a fourth predetermined flow rate, at a fourth location at a fourth preselected distance from the first location. The first, second, third, and fourth components and the premixture together to homogenize the components, to produce the feed product therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The invention will be better understood with reference to the attached drawings, in which: [0015] Fig. 1 A is a side view of an embodiment of a mixer system of the invention;

[0016] Fig. IB is an isometric view of the mixer system of Fig. 1A, drawn at a smaller scale;

[0017] Fig. 1C is a side view of an embodiment of a mixer subsystem of the invention, drawn at a larger scale;

[0018] Fig. 2 is a top view of the mixer subsystem of Fig. 1C;

[0019] Fig. 3 is an isometric view of an embodiment of a mixer assembly of the invention, drawn at a larger scale;

[0020] Fig. 4 is a longitudinal cross-section of the mixer assembly of Fig. 3, drawn at a smaller scale;

[0021] Fig. 5 A is a cross-section of the mixer assembly of Fig. 4, drawn at a larger scale, in which two blade subassemblies located in a body of the mixer assembly are shown in a first position relative to each other;

[0022] Fig. 5B is a portion of the cross-section of Fig. 5A, drawn at a larger scale;

[0023] Fig. 6 is another cross-section of the mixer assembly of Fig. 4 in which the two blade subassemblies are shown in a second position relative to each other, drawn at a smaller scale;

[0024] Fig. 7 is a schematic diagram schematically illustrating a control subsystem for controlling pumps in the mixer system;

[0025] Fig. 8A is a side view of another embodiment of a mixer system of the invention, drawn at a smaller scale;

[0026] Fig. 8B is an isometric view of an alternative embodiment of a mixer assembly of the invention, drawn at a larger scale;

[0027] Fig. 9 is a longitudinal cross-section of the mixer assembly of Fig. 8;

[0028] Fig. 10 is a cross-section of the mixer assembly of Fig. 8, drawn at a larger scale; [0029] Fig. 1 1 is a flow chart schematically illustrating an embodiment of a method of the invention; and

[0030] Fig. 12 is a flow chart schematically illustrating another embodiment of a method of the invention.

DETAILED DESCRIPTION

[0031] In the attached drawings, like reference numerals designate corresponding elements throughout. Reference is first made to Figs. 1A-7 to describe an embodiment of a mixer system of the invention referred to generally by the numeral 20. As will be described, the mixer system 20 is for mixing preselected first, second, third, and fourth components together to produce a feed product (not shown). Preferably, the mixer system 20 includes a mixer subsystem 22 with a mixer assembly 24 including a mixer body 26 extending between first and second ends 28, 30 thereof (Figs. 2, 3), the mixer body 26 defining a cavity 32 therein (Fig. 4). It is also preferred that the mixer assembly 24 includes one or more mixing elements 34 mounted in the mixer body 26 for mixing the first, second, third, and fourth components together in the cavity 32, and for moving the components during mixing thereof in a downstream direction away from the first end 28 and toward the second end 30, to produce the feed product at the second end 30 (Fig. 4). As will also be described, the mixer subsystem 22 preferably also includes respective first, second, third, and fourth reservoirs 36, 38, 40, 42 (Fig. 1C). The first reservoir 36 is for feeding the first component at a first predetermined flow rate into the cavity 32 at a first location 44 at a first preselected distance "Di " from the first end 28 of the mixer body 26 (Fig. 7). The second reservoir 38 is for feeding the second component at a second predetermined flow rate into the cavity 32 at a second location 46 at a second preselected distance "D 2 " from the first end 28 (Fig. 7). The third reservoir 40 is for feeding the third component at a third predetermined flow rate into the cavity 32 at a third location 48 at a third preselected distance "D 3 " from the second location 46 (Fig. 7). The fourth reservoir 42 is for feeding the fourth component at a fourth predetermined flow rate into the cavity 32 at a fourth location 50, the fourth location 50 being located at a fourth preselected distance "D4" from the second location 46 (Fig. 7). As will also be described, it is preferred that the first, second, third and fourth preselected distances "Di" - "D 4 " are selected to permit the first and second components to be mixed together to form a substantially homogeneous premixture, prior to addition of the third and fourth components thereto, and to permit mixture of the third and fourth components with the premixture such that the feed product is substantially homogeneous when provided at the second end 30.

[0032] As will be described, in one embodiment, the first through fourth components preferably are plan substrate, absorbent material, urea, and lactic acid (i.e., lactic acid bacteria) respectively. The components preferably are released or introduced into the cavity at predetermined respective locations on the mixer body to permit interactions between the components to take place. Such interactions are further described below. The interactions are controlled to result in the feed product having preselected attributes. As will also be described, the system 20 provides for adjustment of the rates at which the components flow into the cavity in order to change the preselected attributes of the feed product.

[0033] As can be seen in Fig. I B, it is preferred that "Di" and "D 2 " are substantially similar. In one example, it has been found that the mixer body is suitable where it has a maximum width "W" (Fig. 6) of approximately 1.2 m (approximately 47.2 inches), an overall height "H" (Fig. 6) of approximately 0.9 m (approximately 35.4 inches), and an overall length "L" (Fig. 1C) of approximately 4.5 m (approximately 177.2 inches). In connection with such mixer body, it is preferred that "Di" and "D 2 " are substantially similar. For example, in the embodiment illustrated in Fig. 1 C, "Di " and "D 2 " differ by only approximately 0.4 m (approximately 15.7 inches) or less. (As will be described, in an alternative embodiment (illustrated in Fig. 8), the first and second components preferably are both introduced into the cavity at the first location only.) However, as can also be seen in Fig. 1C, "D3" preferably exceeds "D 2 ". For instance, in the example noted above, "Di" and "D 2 " preferably are about 0.3 m (approximately 1 1.8 inches) and 0.7 m (approximately 27.6 inches) respectively, and "D 3 " preferably is about 1.6 m (approximately 63 inches). As will be described, the differences between these distances are to facilitate mixing the first and second components together into the substantially homogeneous premixture well before the third component is added to the premixture. Also, due to the difference between distances "D 3 " and "D 4 ", the third component preferably is mixed well throughout the premixture before the fourth component is introduced into the cavity.

[0034] As can also be seen in Fig. 1C, a difference between "D 4 " and "D 3 " (i.e., "D 4 " minus "D 3 ") is less than the third distance. As one example, where "D 3 " is approximately 1.6 m (approximately 63 inches), "D 4 " is approximately 2.7 m (approximately 106.3 inches). In this example, the difference between "D 4 " and "D 3 " is approximately 1.1 m (approximately 43.3 inches). As will be described, the difference between "D4" and "D 3 " is selected so as to permit the third component to be thoroughly mixed with the premixture before the fourth component is added.

[0035] The foregoing dimensions are exemplary only. Those skilled in the art would appreciate that the dimensions of any particular mixer subsystem are determined based on a number of factors. As will be described, the mixer subsystem described above may produce up to approximately five tonnes of the feed product per hour. Larger or smaller units may be made to provide greater or smaller amounts of the feed product.

[0036] In one embodiment, the mixer system 20 preferably also includes a packaging subsystem 52 for packaging the feed product after the feed product exits the mixer assembly 24 (Figs. 1A, IB). The packaging subsystem 52 preferably packages the feed product using any suitable method. In one embodiment, the packaging subsystem 52 preferably vacuum- seals the feed product into discrete packages.

[0037] As will be described, the mixing element 34 preferably is rotatably mounted in the mixer body 26. As will also be described, depending on the quantity of the feed product that is desired, the mixer assembly may include one mixing element mounted in the body, or two mixing elements. Each mixing element preferably includes one or more blades "B" arranged in a helical pattern on a rotatable central member 35, as is known in the art. Each mixing element preferably is rotatable about an axis 55 thereof defined by the central member 35, at a predetermined rotation speed, by a suitable driving means (e.g., electric motor(s)). The blades "B" preferably are positioned relative to the axis in any suitable arrangement. It has been found that a pitch of approximately 6° is suitable. Because the manner in which the mixing elements are connected with driving means and driven is well known in the art, further description of such connection is unnecessary.

[0038] It would be appreciated by those skilled in the art that the four components may be various materials and/or substances. For instance, in one embodiment, it is preferred that the first and second components are a plant substrate material and an absorbent material respectively. It is also preferred that the third component is urea and the fourth component is a lactic acid bacteria. However, those skilled in the art would appreciate that, in an alternative embodiment, the first component is an absorbent material, and the second component is a plant substrate material. In another alternative embodiment, the third component is a lactic acid bacteria and the fourth component is urea. In summary, it is preferred that the first, second, third, and fourth components are a plant substrate material, an absorbent material, urea, and a lactic acid bacteria respectively.

[0039] In one embodiment, the mixer assembly 24 preferably also includes one or more shredders 53 positioned for shredding the plant substrate material (Fig. 1A). It is also preferred that, in an alternative embodiment, the mixer assembly 24 preferably includes one or more shredders 53 positioned for shredding the plant substrate material and the absorbent material. For instance, as can be seen in Figs. 1 C and 2, in one embodiment, the shredder 53 preferably is positioned between the first and second reservoirs 36, 38, on one hand, and the first and second locations 44, 46, on the other hand.

[0040] In one embodiment, the mixing element 34 preferably mixes the plant substrate material, the absorbent material, the urea, and the lactic acid together in substantially anaerobic conditions. In addition, it is preferred that the plant substrate material, the absorbent material, the urea, and the lactic acid are substantially homogenized by the mixing element 34, so that the feed product provided at the second end 30 is substantially homogeneous. Also, and as will be described, the plant substrate material is at least partially fermented by the lactic acid as the plant substrate material, the absorbent material, the urea, and the lactic acid are mixed together by the mixing element 34.

[0041] The term "plant substrate" is used herein to encompass plant material having soluble carbohydrate content (including carbohydrates such as glucose, sucrose and pentose). Examples of such plant substrate include, but are not limited to, fruit and vegetable material such as pulp, cores, peelings, rinds, stems, leaves, seeds, roots and the like from a variety of fruits and vegetables such as citrus fruit, e.g. oranges, lemons, limes and grapefruit, apples, pineapple, tomato, beet, banana, avocado, mango, cherimoya, guava, bomb fruit, cucumber, melon, berries and the like. It will be understood that "plant substrate" may include any combination(s) of some or all of the foregoing materials.

[0042] The term "absorbent material" is used herein to refer to a material that is able to absorb an amount of liquid, including but not limited to, cereal straw such as grass, hay, bean straw, sugar cane bagasse, straw of corn and other grains, wheat straw, rice straw, barley straw, soybean straw, bran such as oat bran, forage flour, flour of corn stubble and other flours, corn stover and the like. It will be understood that "absorbent material" may include any combination(s) of some or all of the foregoing materials.

[0043] The term "urea" is used herein to refer to an organic compound with the chemical formula CO(NH 2 ) 2 . As is known in the art, urea may be a convenient source of nitrogen.

[0044] The term "lactic acid bacteria" is used herein to encompass bacteria that produce lactic acid and are suitable for use in food fermentation, and for the purposes hereof, also includes lactic acid. (For the purposes hereof, it will be understood that "fermentation" refers to lactic acid fermentation.) Generally, lactic acid bacteria that can adequately ferment a plant substrate are used, e.g. can cause fermentation to yield a pH of less than about 3.6 in the fermented product. Examples of lactic acid bacteria for use in the present method include, but are not necessarily limited to, Lactobacillus, such as L. acidophilus, L. brevis, L. fermentum and L. casei; Leuconostoc, such as L. plantarum and L. lactis; Pediococcus, Lactococcus, and Streptococcus, such as S. salivarius ssp. thermophilus. (It will also be understood that "lactic acid" referred to herein includes lactic acid bacteria.)

[0045] The components may be mixed together in any suitable relative proportions, in order to provide the feed mixture with any particularly desired attributes. For instance, as is known in the art, the feed mixture preferably includes the components in the following proportions, by volume: plant substrate, approximately 80%; absorbent material, approximately 18%; urea, approximately 1 %; and lactic acid, approximately 1%.

[0046] However, as is known in the art, the relative proportions of the components are adjusted in order to provide desired attributes to the feed mixture. (For instance, see "Evaluacion de diferentes materials absorbents para ensilar hollejo de citric" (Evaluation of Different Absorbent Materials for Silage of Citrus Peels), Pastos y Forrajes, Vol. 26, No. 4, 2003.) For example, if it is desired to provide a feed mixture that tends to cause the animals eating it to gain weight (e.g., beef cattle), then the proportions are adjusted accordingly. As will be described, the system herein includes means for adjusting the relative proportions of the components in the feed mixture.

[0047] Prior to admixture, the plant substrate and the absorbent material are prepared for the fermentation by processing to reduce the particle size to about 2 cm (approximately

0.79 inch) or less in diameter, i.e., the preferred maximum particle size is about 2 cm. As described above, it is preferred that this is accomplished by the shredder 53, positioned to shred the plant substrate and the absorbent material shortly before those materials are directed into the cavity 32. Thus, the plant substrate (including, for example, fruit and vegetables rinds, peelings, stems, and seeds) and the absorbent material preferably are milled or chopped in order to attain a mixture of consistent particle size throughout. The more consistent particle size promotes mixing, thereby facilitating homogeneity. In the event that the plant substrate has a dry material content of less than about 25%, it may be desirable to dry the plant substrate to remove the excess water and increase the dry material content before adding the plant substrate to the first reservoir 36. At this step in the process, the interaction between the plant substrate and the absorbent material is their mixture together to form a substantially homogeneous premixture.

[0048] As will be described, it is preferred that the mixer subsystem operates on a

"continuous batch" basis.

[0049] As noted above (and as can be seen in Fig. 7), the distance "D 3 " is relatively large, compared to the relatively small difference between "Di " and "D 2 ". This is to permit the first and second components (i.e., the plant substrate and the absorbent material) to be thoroughly mixed into the substantially homogeneous premixture before the third component (i.e., the urea) is added. As can also be seen in Figs. 1C and 3, there is also a distance defined by the difference between "D 3 " and "D4". This is to permit the urea to be well mixed with the premixture before the fourth component (i.e., the lactic acid) is directed into the cavity 32,

1. e., at the fourth location 50. In addition, and as will be described, control of the proportions of the components permits adjustment thereof so that the feed product has preselected attributes. At this point, the interaction between the urea and the premixture is further mixing, so that the urea is mixed substantially evenly throughout the plant substrate and the absorbent material. [0050] Generally, the plant substrate has a soluble carbohydrate content of at least about 5%, and preferably a soluble carbohydrate content of at least about 8% or more as measured using established techniques such as chemical analytical techniques accepted by AOAC (1995).

[0051] Once the plant substrate is prepared, it is combined with an absorbent material, urea and lactic acid bacteria under anaerobic conditions to yield a mixture having at least about 30% dry material content measured using established techniques such as chemical analytical techniques accepted by AO AC (1995). To calculate the percentage of absorbent material required to generate a mixture having at least about 30% dry material content, the following equation may be used:

Percent of absorbent material to add = (DM of Plant substrate- 300) X 100)

(DM of Plant substrate-DM Abs. Mat) in which DM Plant substrate is the dry material content of the fresh plant substrate and DM Abs. Mat is the dry material content of the absorbent material in g of DM Kg. It has been found that the absorbent material permits control of moisture content of the feed product.

[0052] As noted above, the mixture is homogenized to provide the substantially homogeneous feed product, and the feed product is put into a sealed container, e.g., a plastic bag, under conditions suitable to prevent the production of undesirable bacteria capable of producing undesirable secondary fermentation products such as butyric acid, propionic acid, isobutyric acid, isovaleric acid, valeric acid and amines, like putrecina, ornitinea and cadaverine. For the purposes hereof, it will be understood that "homogenize" refers to making uniform or similar, or causing something (e.g., a mixture) to be homogeneous. Suitable conditions include introducing the homogenized feed product into the sealed container at a temperature of no more than about 25 °C, for example, in the range of about 15 - 25 °C, and as soon as possible, e.g. no more than about four hours, and preferably no more than about two to three hours, following homogenization to avoid aerobic conditions that encourage the growth of undesirable bacteria in the mixture.

[0053] While not wishing to be bound by any particular mode of action, it appears that the lactic acid bacteria utilize, in the presence of urea, the carbohydrates available from the plant substrate, and convert the non-protein nitrogen of the urea into protein, thereby increasing the nutritional value of the plant substrate and transforming the waste substrate into a protein-based food product. This is another interaction, involving the lactic acid, the urea, and the plant substrate.

[0054] From the foregoing description, it can be seen that the configuration of the mixer subsystem 22 preferably is as described above in order to provide the substantially homogeneous feed product. In one embodiment, illustrated in Figs. 1A-7, two mixing elements (identified in Figs. 5A and 6 as 34A and 34B for convenience) preferably are mounted in the mixer body 26. In this embodiment, the mixer subsystem 22 preferably is sized to generate up to approximately five tonnes of the feed product per hour. Those skilled in the art would appreciate that, once produced, the feed product may spoil if it is not properly packaged. Accordingly, as noted above, the system 20 preferably includes the packaging subsystem 52, to package the feed product in suitable packages (e.g., vacuum- sealed packages) after the feed product has exited the mixer body 26.

[0055] In one embodiment, the mixing elements 34A, 34B preferably are two blade subassemblies that are at least partially positioned in the cavity 32, for mixing the components together to produce the feed product. The blade subassemblies 34A, 34B include the blades "B" mounted on rotatable central members 35A, 35B respectively. The central members 35A, 35B are rotatable about respective axes defined thereby.

[0056] As can be seen in Figs. 5A and 6, the cavity 32 preferably is at least partially defined by one or more internal surfaces 54 of the body 26. Preferably, the internal surface 54 includes a lower portion 56 thereof at least partially defining respective spaces in which the blade subassemblies 34A, 34B are at least partially located. It is also preferred that the internal surface 54 includes an upper portion 60 thereof at least partially spaced apart from the blade subassemblies 34A, 34B by a minimum preselected central distance for each blade subassembly respectively (designated as "Ci " and "C 2 " in Fig. 5 A) to at least partially define an upper part 62 of the cavity 32 located above the blade subassemblies 34A, 34B to facilitate mixing the components together. As can be seen in Fig. 5A, the minimum preselected central distance "Ci", "C 2 " for each of the blade subassemblies is measured substantially vertically from a central axis of rotation of the blade subassembly. As an example, in one embodiment, where the overall width " W" of the mixer body is approximately 1.2 m (approximately 47.2 inches) and the approximate overall height "H" of the mixer body is approximately 1.9 m (approximately 35.4 inches), each of the distances "Ci " and "C 2 " may be approximately 0.5 m (approximately 19.7 inches). [0057] As can also be seen in Figs. 5A and 6, the lower portion 56 preferably defines respective channels 64A, 64B in which each of the blade subassemblies 34A, 34B is positioned. Preferably, each of the channels 64A, 64B has a profile substantially parallel to an outer profile of each of said at least two blade subassemblies respectively. For instance, when the blade subassembly 34A is rotating, its blades or members define an outer profile thereof represented by the dashed line identified in Fig. 5 A as "Pi". As shown in Fig. 5B, the lower portion 56 defines an arc "Aj" substantially parallel to a part of the profile "Pi ". Fig. 5B illustrates that the lower portion 56 is positioned a sufficient distance away from the blade subassembly 34A to permit rotation of the blades B with low risk of material accumulating between the lower portion and the blades to impede or interrupt rotation of the blades of the blade subassembly 34A. Such distance is designated "D 5 " in Fig. 5B.

[0058] It can also be seen in Figs. 5A and 6 that the blade subassembly 34B is also positioned proximal to the lower portion defining an arc substantially parallel to an outer profile defined by the blades of the blade subassembly 34B. As can be seen in Fig. 5A, the rotating blade subassembly 34B also defines a profile "P 2 ", and the lower portion 56 also defines a second arc "A 2 " that accommodates the profile "P2" with a sufficient distance therebetween. Because the arrangement of the blade subassembly 34B in the body is substantially the same as that of the blade subassembly 34A, further description thereof is unnecessary.

[0059] As can also be seen in Figs. 5A and 6, it is preferred that the upper and lower portions, taken together, generally resemble an inverted heart-shaped figure, i.e., the interior surface of the mixer body is generally obcordate. The upper portion preferably is defined by a single arc "A3".

[0060] Preferably, the upper part 62 of the cavity 32 permits the components to be at least partially thrown therethrough from one of the two blade subassemblies 34A, 34B to the other as the components are mixed by the blade subassemblies. For instance, as schematically shown in Fig. 6 for exemplary purposes, material moved by the blade subassembly 34A into the upper cavity 62 has a trajectory approximately represented by "Ti ", and material moved by the blade subassembly 34B into the upper cavity 62 has a trajectory approximately represented by "T 2 ". [0061] As noted above, the proportions of the components in the feed product may be adjusted so that the feed product has preselected attributes. In one embodiment, the mixer system 20 preferably also includes a control subsystem 66 for controlling movement of the components respectively into the cavity 32, to result in predetermined proportions of the respective components in the feed product. In this way, the feed product can be adjusted to have certain attributes or characteristics, to promote selected attributes of the animals that will consume the feed product. The respective proportions of the components in the feed product can easily be adjusted via the control subsystem 66 (Fig. 7). The control subsystem 66 preferably includes flow control means 68, 70, 72, 74 for controlling respective flow rates of the four components into the first through fourth reservoirs 36, 38, 40, and 42 respectively. Those skilled in the art would be aware of suitable flow control means. Preferably, the flow control means 68, 70, 72, 74 are controllable respectively via a control panel 76. Signals from the control panel 76 are transmitted to the flow control means 68, 70, 72, 74 via transmission means 77. Those skilled in the art would be aware of suitable control panels and suitable transmission means.

[0062] An embodiment of a method 181 of the invention is schematically illustrated in Fig. 1 1. In use, the method 181 includes providing the mixer body 26 extending between the first and second ends 28, 30 thereof (Fig. 1 1 , step 183). Next, one or more mixing elements 34 are provided mounted in the mixer body 26 for mixing the first, second, third, and fourth components together in the cavity 32, and for moving the components during mixing thereof in a downstream direction away from the first end and toward the second end (step 185). The first component is directed into the cavity at a first predetermined flow rate, at a first location at a first preselected distance from the first end of the body (step 187). The second component is directed into the cavity at a second predetermined flow rate, at a second location at a second preselected distance from the first end of the body (step 189). The first and second components are mixed together to provide the substantially homogeneous premixture while moving the first and second components in the downstream direction from the second location (step 191). The third component is directed into the cavity at a third predetermined flow rate, at a third location at a third preselected distance from the second location (step 193). The third component and the premixture are mixed together, to substantially evenly distribute the third component throughout the premixture (step 195). The fourth component is directed into the cavity at a fourth predetermined flow rate, at a fourth location at a fourth preselected distance from the second location (step 197). The first, second, third, and fourth components are mixed together to homogenize the components, to produce the feed product therefrom (step 99).

[0063] In one embodiment, the method 181 preferably also includes, immediately following step 189, the step of shredding the first and second components to the preselected maximum particle size (step 101).

[0064] As noted above, the first, second, third, and fourth components preferably are the plant substrate material, the absorbent material, urea, and the lactic acid respectively. Preferably, the plant substrate comprises carbohydrates, the urea comprises non-protein nitrogen, and in the presence of the urea, the lactic acid utilizes at least a portion of the carbohydrates in the plant substrate material to convert the non-protein nitrogen to provide protein in the feed product.

[0065] It is also preferred that the plant substrate material, the absorbent material, the urea, and the lactic acid bacteria are mixed together in substantially anaerobic conditions.

[0066] It is also preferred that the mixer subsystem 22 includes a support subassembly 80 (Figs. 1C, 2) for supporting the mixer subassembly 24 and certain related elements. Those skilled in the art would be aware of a variety of suitable materials and a variety of suitable methods of connecting such materials, to form the support subassembly 80. In one embodiment, the first reservoir 36 preferably is a hopper (Fig. 1C) positioned for directing the first component into the cavity 32 at the first location 44 via a first opening 82 in the mixer body 26 (Fig. 3). As can be seen in Figs. 1 C, 2, and 3, the first opening 82 preferably is positioned substantially at the first end 28. As noted above, the plant substrate forms the largest proportion of the animal feed product, and accordingly it is preferred that the plant substrate is the first component introduced via the hopper 36 and through the first opening 82, substantially at the first end 28.

[0067] Preferably, the second reservoir 38 is another hopper, positioned for directing the second component (i.e., the absorbent material) into the cavity 32 at the second location 46 via a second opening 84 in the mixer body 26 (Fig. 3).

[0068] As can be seen in Figs. 1 A-1C, the shredder 53 preferably is positioned between the hoppers 36, 38 and the respective openings 82, 84 therefor. Those skilled in the art would be aware of suitable shredders. Preferably, the shredder is a blade-type shredder, set up for shredding the plant substrate material exiting at the bottom of the first hopper 36 and the absorbent material exiting at the bottom of the second hopper 38 under the influence of gravity to a maximum of about 2 cm in diameter, i.e., to about -2 cm, as noted above. This arrangement facilitates substantially uniform sizing of the plant substrate and the absorbent material.

[0069] Chopping or shredding the plant substrate and the absorbent material to about

2 cm in diameter or less is done for the following reasons:

(a) to facilitate mixing of the plant substrate and the absorbent material with each other, and also with the other materials included in the animal feed product;

(b) to improve the digestibility of the animal feed product which is ultimately produced by the mixer system 20; and

(c) to facilitate packaging of the animal feed product (i.e., the product may be packaged more densely if the materials therein are relatively small).

[0070] The flow of the plant substrate and the absorbent material into the first and second hoppers 36, 38 is controlled via respective conveyors 68, 70 (also identified as "Gi" and "G 2 " in Fig. 7) positioned to move the materials into the hoppers 36, 38 respectively. It will be understood that Fig. 7 is a schematic illustration, indicating schematically that the conveyors "Gi ", "G 2 " are controlled by the control panel. The conveyors "Gl ", "G2" are controlled respectively to signals received from the control panel 76 via signal transmission means 77. By controlling the speeds of the conveyors "Gl ", "G2", the proportions of the plant substrate and the absorbent material in the hoppers 36, 38 relative to each other are controlled. For example, the feed product may be intended to have certain proportions of plant substrate and absorbent material relative to each other, i.e., in order that the feed product will have preselected attributes, to promote specific attributes or characteristics in the animals that consume the feed product. The conveyors "Gi" and "G 2 " preferably are controlled to operate at speeds that will result in the appropriate amounts (whether by volume, or by weight) of the plant substrate and the absorbent material that are needed being placed in the hoppers 36, 38, by the conveyors 68, 70. The plant substrate and the absorbent material fall into the cavity through first and second openings 82, 84 under the influence of gravity. As noted above, before falling into the cavity, the plant substrate and the absorbent material preferably are shredded. Because those skilled in the art would be aware of suitable conveyors and control devices and means therefor, further description of the control of the conveyors "Gi ", "G 2 " is unnecessary.

[0071] The other materials (i.e., urea, and lactic acid) are directed into the cavity 32 via additional openings 86, 88 respectively, at the third and fourth locations 48, 50 (Fig. 7). As noted above, the openings 86, 88 are also positioned at predetermined distances from the other openings 82, 84. The control panel 76 also controls the pumps 72, 74 (i.e., the rates of flow of the urea and the lactic acid into the cavity) via the transmission means 77, to provide the feed product with the preselected attributes.

[0072] It is preferred that the third and fourth reservoirs 40, 42 are respective tanks

(Fig. 1C) in which the urea and lactic acid are stored respectively. Pumps 72, 74 are operatively connected to the tanks 40, 42 respectively to deliver urea and lactic acid therefrom into the cavity 32 via the third and fourth openings 86, 88 at respective preselected flow rates.

INDUSTRIAL APPLICABILITY

[0073] In use, the plant substrate (not shown) is positioned in the first hopper 36 and moves through the shredder 53 and into the cavity 32 under the influence of gravity. Preferably, at substantially the same time, the absorbent material (not shown) is positioned in the second hopper 38, and the absorbent material also moves through the shredder 53 and into the cavity 32 under the influence of gravity. Preferably, the blade subassemblies 34A, 34B are rotating about their respective central members as the plant substrate and the absorbent material enter the cavity 32. Preferably, the blade subassemblies 34A, 34B are rotated at a speed or speeds sufficient to mix the four components in one batch sufficiently in about 20 minutes.

[0074] For example, in Fig. 6, the direction of rotation of the central member 35 A in the blade subassembly 34A is indicated by arrow "Xj ", and the direction of rotation of the central member 35B in the blade subassembly 34B is indicated by arrow "X 2 ". At least parts of the components preferably are moved through the cavity 32 from one blade subassembly to another, as schematically indicated by arrows "Ti " and "T 2 " in Figs. 5 and 6. Preferably, the materials are thrown by one blade subassembly directly to the other (and vice versa) so that the materials preferably strike blades which are moving, the idea being that the mixing thereby achieved is somewhat more thorough because of the dynamic engagement of the materials with the blades. The materials thrown by a first blade subassembly preferably strike the moving blades of the other blade subassembly, to achieve a dynamic mixing. Those skilled in the art would appreciate that materials which are so thrown or cast by one blade subassembly may not necessarily strike the other blade subassembly, e.g., the thrown materials may instead, in whole or in part, strike the upper or lower portions, subsequently to be engaged by the blades, and thrown again through the upper part 62 of the cavity. As the components are being mixed, they are also moved in the downstream direction (i.e., from the first end to the second end) by the blade subassemblies 34A, 34B, as schematically indicated by arrow "M" in Figs. 1C and 7. (It will be understood that the blade subassemblies 34A, 34B are omitted from Fig. 7 for clarity of illustration.)

[0075] As can be seen in Figs. 1A and 1C, once mixed, the feed product is pushed by the mixing element(s) 34A, 34B out of the mixer body 26 at the second end 30 thereof, as indicated by arrow "Y". The product is homogenized due to the processing (described above) in the mixer body 26.

[0076] Those skilled in the art would appreciate that the system 20 may operate without the packaging subassembly 52. However, in practice, due to the relative large amount of feed product producible from the system 20 over a relatively short time period, and because the feed product is perishable if not properly packaged, it is preferred that the feed product is packaged unless it can be consumed shortly after production thereof.

[0077] A funnel 94 positioned at the second end 30 directs the feed product exiting the mixer body 26 to a conveyor 96 (Fig. 1A). The conveyor 96 is positioned to transfer the product in the direction indicated by arrow "Z" in Fig. 1A to the packaging subassembly 52 of the mixer system 20. As can be seen in Figs. 1A and I B, in one embodiment, the packaging subassembly 52 preferably includes a product hopper 98 in which the product is temporarily collected. In conventional fashion, a bag or other suitable container 202 is positioned underneath the product hopper 98 and filled. (Those skilled in the art would be aware that the bag 202 is not shown in position under the hopper 98 in Fig. IB for clarity of illustration.) Once the product is in the bag 202, the bag 202 preferably is then vacuum- sealed, at a vacuum sealing station 204 (Fig. IB). It will be appreciated that, in operation, a number of bags are filled with product in sequence, and subsequently vacuum-sealed in sequence. Among the advantages of packaging the product in relatively small bags and vacuum-sealing same is the relatively long shelf life achieved due to the packaging. [0078] Those skilled in the art would also appreciate that the system may be sized and configured to produce a range of amounts over a particular time period. An alternative embodiment of the mixer system 320 of the invention is illustrated in Figs. 8A-10. As can be seen in Figs. 9 and 10, a mixer assembly 324 included in the system 320 preferably includes only one blade subassembly 334. The mixer system 320 preferably is for use where the maximum rate at which the feed product is produced thereby is relatively low, i.e., about 1 tonne per hour. At relatively low rates of production, a mixer body 326 and a cavity 332 therein is required to be relatively smaller, so that the plant substrate, the absorbent material, the urea, and the lactic acid are mixed thoroughly, as smaller volumes thereof are mixed.

[0079] It will be understood that the mixer system 320 which has additional elements corresponding to the elements of the larger mixer system 20 described above. As can be seen in Figs. 8A-10, the mixer body 326 preferably extends between first and second ends 328, 330 and defines a cavity 332 therein. Also, the mixing element (i.e., blade subassembly) 334 preferably has a central member 335 to which a number of blades "B" are attached. The central member 335 defines an axis 355 about which the central member 335 rotates. The blades are formed and positioned to move the materials in the cavity 332 to mix the four components together thoroughly, substantially in the same manner as described above, in connection with the mixer system 20. As the four components are mixed together, they are moved in a generally downstream direction, i.e., from the first end to the second end, by the mixing element 334. Those skilled in the art would appreciate that the blades may be formed and positioned relative to the central member in any suitable manner. In one embodiment, it has been found that the blades preferably have a pitch of about 6°.

[0080] As can be seen in Fig. 8B, the body 326 preferably includes first, third and fourth openings 379, 386, and 388. It is preferred that the plant substrate and the absorbent material are directed into the cavity 332 of the mixer body 326 via the first opening 379. Accordingly, another major difference between the system 320 and the system 20 described above is that, in the mixer system 320, first and second components preferably are introduced into the cavity 332 via the same opening, at the first location. Also, the urea and the lactic acid preferably are directed into the cavity 332 via third and fourth openings 386, 388.

[0081] Preferably, the mixer subsystem 322 includes two hoppers 336, 338 (Fig. 8A) in which the plant substrate and the absorbent material are separately accumulated, before the plant substrate and the absorbent material are allowed to fall into the cavity, due to gravity. As can be seen in Fig. 9, the opening 379 (i.e., the center thereof) is located proximal to the first end 328 (i.e., at a first preselected distance "2Di " from the first end 328), and the third and fourth openings 386, 388 are located in the downstream direction, away from the first end, and toward the second end, at preselected distances (designated "2D3" and "2D 4 " respectively in Fig. 9) relative to the opening 379. Those skilled in the art would also appreciate that the openings 379, 386, and 388 are positioned relative to each other so that the plant substrate and the absorbent material are thoroughly mixed together into the substantially homogeneous premixture before the urea is introduced into the premixture, and the third and fourth openings are located relative to each other to permit the urea to be thoroughly mixed with the premixture before the lactic acid is introduced into the cavity 332. The mixer subsystem 322 preferably includes a shredder 353 (Fig. 8A) for shredding the plant substrate and the absorbent material shortly before they are introduced into the cavity 332. As described above, the plant substrate and the absorbent material preferably are shredded to a maximum particle size of about 2 cm (approximately 0.79 inch).

[0082] In the same manner as described above, the plant substrate and the absorbent material is introduced via the opening 379, at a first location 344. The urea and the lactic acid bacteria also are preferably introduced to the internal cavity 332 at second and third locations 348, 350 respectively.

[0083] It will be understood that, as shown in Fig. 8A, the mixer system 320 preferably includes a number of other elements (e.g., the packaging subassembly and the control subsystem) corresponding to such other elements in the mixer system 20, described above.

[0084] An embodiment of a method 481 of the invention is schematically illustrated in Fig. 12. The method 481 includes providing the mixer body 326 extending between first and second ends 328, 330 thereof, the mixer body defining the cavity 332 therein (Fig. 12, step 483). The mixing element 334 is provided, mounted in the mixer body 326, for mixing the first, second, third, and fourth components together in the cavity 332, and for moving the components during mixing thereof in the downstream direction away from the first end 328 and toward the second end 330 (step 485). The first component is directed into the cavity 332 at a first predetermined flow rate, at the first location 344 at the first preselected distance "2Di " from the first end 328 of the body 326 (step 487). The second component is directed into the cavity 332 at a second predetermined flow rate, at the first location 344 (step 489). The first and second components are mixed together to provide a substantially homogeneous premixture while moving the first and second components in the downstream direction from the first location 344 (step 491). The third component is directed into the cavity 332 at a third predetermined flow rate, at the third location 348 at the third preselected distance "2D3" from the first location 344 (step 493). The third component and the premixture are mixed together, to substantially evenly distribute the third component throughout the premixture (step 495). The fourth component is directed into the cavity at a fourth predetermined flow rate, at the fourth location 350 at the fourth preselected distance "2D 4 " from the first location 344 (step 497). The first, second, third, and fourth components are mixed together to homogenize the components, to produce the feed product therefrom (step 499).

[0085] In one embodiment, the method 481 preferably also includes, immediately following step 489, the step of shredding the first and second components to the preselected maximum particle size (step 401 ).

[0086] It will be appreciated by those skilled in the art that the invention can take many forms, and that such forms are within the scope of the invention as claimed. Therefore, the spirit and scope of the appended claims should not be limited to the descriptions of the preferred versions contained herein.