Paddle, paddle rail, mixer shaft for a mixer, mixer and method for mixing

Abstract

A paddle (30), a paddle rail (20), a mixer shaft (10) for a mixer (1), a mixer (1) and a method for mixing a product to be conditioned in a mixer (1). As the mixer (1) starts up, a product to be mixed is retained in a starting region of the mixer shaft (10), for instance, until the desired mixing or conditioning is achieved, so that loss-free start-up is made possible. That is to say disposal or recycling of the product when the mixer starts up becomes unnecessary.

Claims

1. A conditioner having at least one mixer shaft, on which at least one paddle is arranged in an initial region of the mixer shaft, wherein the at least one paddle comprises a planar element which has a working face and a back face and is positioned, during intended use, substantially on a plane perpendicular to an axis of rotation of the mixer shaft, and has a fastener fastening the paddle on the mixer shaft, the working face being inclined by a working angle on one side and the back face being inclined by a back angle on the other side of the plane perpendicular to the axis of rotation of the mixer shaft, the back angle is smaller than the working angle, and has other elements arranged in a region neighboring the initial region of the mixer shaft, and the conditioner, the mixer shaft and the at least one paddle are embodied in such a manner that: during rotation of the mixer shaft in a first direction of rotation, a product which is to be conditioned and which partially fills the conditioner, is essentially not conveyed by the paddle in a direction parallel to the mixer shaft, such that the product is kept in the initial region of the mixer shaft, and wherein the other elements either bring about no conveying of the product in a direction parallel to the mixer shaft or bring about backward conveying of the product; and during rotation of the mixer shaft in a second direction of rotation, the at least one paddle conveys the product in a direction parallel to the mixer shaft, whereby the product is conveyed, via the region neighboring the initial region of the mixer shaft, to an outlet of the conditioner.

2. A method for mixing a product to be conditioned in a conditioner as claimed in claim 1, said method comprising the following steps: partially filling the conditioner with the product to be conditioned, rotating the mixer shaft of the conditioner in a first direction of rotation such that at least one paddle arranged on the mixer shaft in an initial region of the mixer shaft essentially does not convey the product in a direction parallel to the mixer shaft, such that the product is kept in the initial region of the mixer shaft, and in a region neighboring the initial region of the mixer shaft other elements are arranged, which other elements either bring about no conveying of the product in a direction parallel to the mixer shaft or bring about backward conveying of the product, the paddle comprises a planar element which has a working face and a back face and is positioned, during intended use, substantially on a plane perpendicular to an axis of rotation of the mixer shaft, and has a fastener fastening the paddle on the mixer shaft, the working face being inclined by a working angle on one side and the back face being inclined by a back angle on the other side of the plane perpendicular to the axis of rotation of the mixer shaft, and the back angle is smaller than the working angle, and rotating the mixer shaft in a second direction of rotation such that the at least one paddle conveys the material in a direction parallel to the mixer shaft, whereby the product is conveyed via the region neighboring the initial region of the mixer shaft to an outlet of the conditioner.

3. The method as claimed in claim 2, wherein the steps of rotation in the first direction of rotation and in the second direction of rotation are repeated several times.

4. The method as claimed in claim 2, wherein, before or during the step of rotation in the first direction of rotation, the product is mixed by at least one of compressed air or steam.

5. The conditioner as claimed in claim 1, wherein an inclination of the conditioner is adjustable.

6. The conditioner as claimed in claim 1, wherein a sum total of working angle and back angle is between 4 and 50.

7. The conditioner as claimed in claim 1, wherein the paddle has a cutting edge or cutting face which, when used as intended, extends proceeding from a region adjacent to the mixer shaft as far as a substantially outermost dimension of the paddle, the cutting edge or the at least one of the cutting face or the mixing face is arranged in a substantially radial manner in relation to the mixer shaft during intended use.

8. The conditioner as claimed in claim 7, wherein the mixing face includes a mixing angle of between 40 and 86 with the back face.

9. The conditioner as claimed in claim 1, wherein a paddle rail comprises a paddle holder and one or more paddles, the paddle rail is mounted on the mixing shaft, and the one or more paddles, comprised by the paddle rail, are arranged on the mixer shaft.

10. The conditioner as claimed in claim 9, further comprising a plurality of scrapers for stripping the product, which is intended to be conditioned, from a housing wall of the conditioner, and the scrapers are respectively arranged on the working face or the back face of each paddle.

11. The conditioner as claimed in claim 10, wherein the ends of each of the scrapers are provided with respective connectors which connect the scraper of one paddle to the scraper of a paddle which rotational follows or precedes the scraper, when used as intended.

12. The conditioner as claimed in claim 1, wherein at least one of the working angle or the back angle of at least one of the paddles, arranged on the mixer shaft, is variable.

Description

(1) A further possibility for holding and mixing the material to be mixed in an initial region, of the mixer shaft consists in orienting the nozzles in such a manner that a flow of compressed air and/or steam counter to the actual conveying direction is generated. The invention will be explained in more detail, hereinbelow with reference to FIGS. which merely show exemplary embodiments and in which:

(2) FIG. 1a: shows a plan view of a paddle according to the invention,

(3) FIG. 1b: shows a perspective view of the paddle as shown in FIG. 1a,

(4) FIG. 1c: shows a cross section through the paddle as shown in FIG. 1a along the line A-A,

(5) FIG. 1d: shows a cross section through a second embodiment of a paddle,

(6) FIG. 1e: shows a cross section through a third embodiment of a paddle,

(7) FIG. 1f: shows a schematic cross section through a fourth embodiment of a paddle in the case of rotation in the turning direction,

(8) FIG. 1g: shows a schematic cross section of the paddle as shown in FIG. 1f in the case of backward turning,

(9) FIG. 1h: shows a schematic perspective view of a fifth embodiment of a paddle with a closed paddle flap,

(10) FIG. 1i: shows the paddle as shown in FIG. 1h with an open paddle flap,

(11) FIG. 1j: shows a cross section through a sixth embodiment of a paddle,

(12) FIG. 2a: shows a plain view of a paddle rail according to the invention.

(13) FIG. 2b: shows a perspective view of the paddle rail as shown in FIG. 2a,

(14) FIG. 2c: shows a side view of the paddle rail as shown in FIG. 2a,

(15) FIG. 2d: shows a schematic cross section of a farther embodiment of a paddle rail,

(16) FIG. 2e: shows a schematic cross section of a third embodiment of a paddle rail,

(17) FIG. 2f: shows a schematic side view of a paddle with scrapers fastened thereon,

(18) FIG. 3a: shows a plan view of a mixer shaft according to the invention,

(19) FIG. 3b: shows a perspective view of the mixer shaft as shown in FIG. 3a,

(20) FIG. 4a: shows a plan view of a mixer according to the invention, and

(21) FIG. 4b: shows a perspective view of the mixer as shown in FIG. 4a.

(22) FIGS. 1a to 1c show a paddle 30 according to the invention. Here, FIG. 1a shows the paddle 30 in a plan view, FIG. 1b shows the paddle 30 in a perspective view and FIG. 1c shows the paddle 30 in a cross section along the line A-A as shown in FIG. 1a. The paddle 30 is essentially a planar element of wedge-shaped form.

(23) On the leading side as considered in the direction of rotation R, the paddle 30 has a cutting edge 37, which is abraded to form a cutting face in the embodiment shown, however. This cutting edge 37 is formed as a line of intersection between the working face 33 and the back face 34, which are at an angle to one another.

(24) A mixing face 38 is formed on the side located opposite the cutting edge 37, i.e. in the opposite direction of rotation R.

(25) The paddle 30 furthermore has a continuous opening 35 between the working face 33 and the back face 34. Moreover, on that side which is assigned to a mixing shaft during intended use, the paddle 30 has a fastening means 32 in the form of a stud. The side located opposite the fastening means 32 has a curved configuration, the curvature corresponding to a housing wall 2 (see FIG. 4b) of a mixer.

(26) During intended use, the paddle 30 is arranged substantially on a plane 13 perpendicular to an axis of rotation of a mixer shaft. The back face 34 is, however, inclined in relation to this perpendicular plane 13 and includes a back angle 43 with the plane thereof. The working face 33 is likewise inclined with respect to the perpendicular plane 13 and includes a working angle 42. In this respect, it is always the case, however, that the working angle 42 is greater than the back angle 43.

(27) The cutting edge 37 does not have a sharp form, but instead has on average a radius of approximately 2 mm. This radius can be adapted depending on the planned use. Alternatively, instead of a radius, it is also possible for a sharp cutting edge 37 or a blunt cutting edge 37 with a cutting face to be formed. The mixing face 38 located opposite the cutting edge 37 protrudes at a mixing angle 39 from the back face 34.

(28) It goes without saying that ail faces, namely the working face 33, the back face 34 and the mixing face 38, can also be formed as curved faces. The corresponding angles, the working angle 42, the back angle 43 and the mixing angle 39, are then to be defined by means of an imaginary straight line through the end points of the corresponding faces.

(29) During intended use, both the cutting edge 37 and the mixing face 38 extend proceeding from a mixer shaft 10 (see FIGS. 3a and 3b) as far as the outermost dimension of the paddle 30. During intended use, this outer dimension of the paddle 30 extends substantially as far as an inner side of a housing wall 2 (see FIG. 4b). It goes without saying that in this case there is always a certain gap between the housing wall 2 and the paddle 30 in the order of magnitude of 1 mm to 10 mm.

(30) FIG. 1d shows a possible configuration of the paddle 30, consisting of a square profile 50 with a metal sheet 51 of v-shaped cross section fastened thereon.

(31) FIG. 1e shows a paddle 30 formed from a single bent metal sheet 52. In this case, the imaginary working face 33 and back face 34 are represented by the lines with dashes and two dots, which each extend from the corresponding edge of the mixing face 38 as far as the cutting edge. The rest of the component parts correspond to those shown in FIGS. 1a to 1c.

(32) FIGS. 1f and 1g schematically show the mode of operation of a paddle 30 made from a flexible material. In the direction of rotation R of the mixer shaft 10, the working face 33, which is arranged at a working angle 42 in relation to the plane 13, is not compliant. In the direction of rotation R, however, the paddle 30 is deformed by the product to be mixed, such as to form a back face 34 with a back angle 43 which is smaller than the working angle 42 in relation to the plane 13.

(33) FIGS. 1h and 1i show a paddle 30 consisting of a paddle frame 54, on which a paddle flap 55, which is part of the working face 33, is articulated by means of a hinge 56. The paddle frame 54 and the paddle flap 55 are arranged on a mixer shaft in such a manner that, in the direction of rotation R, the paddle flap 55 remains closed by virtue of the pressure generated by the product on the paddle flap 55. In the direction of rotation R, the product exerts a pressure on the back face (not visible) of the paddle 30 which causes the paddle flap 55 to be opened, such that the product is not conveyed. In addition, provision may be made of means for holding the paddle flap 55 in the closed position, e.g. magnets, which allow the paddle flap to be opened only above a settable pressure threshold value. Provision may also be made of means for closing the paddle flap 55, e.g. a spring, which assist in closing the paddle flap 55.

(34) Alternatively, the entire paddle can be articulated on the mixer shaft and the movement thereof can be delimited by stop elements, the position of the stop elements preferably being adjustable.

(35) FIG. 1j shows a paddle 30 in which the working angle can be adjusted by means of a pneumatic element 57. Alternatively, the back angle can be adjusted in a similar way. It is also conceivable for both the working angle 42 and the back angle 43 or the orientation of the paddle 30 to be adjustable.

(36) FIGS. 2a to 2c show a paddle rail 20 according to the invention. FIG. 2a shows a plan view, FIG. 2b shows a perspective view and FIG. 2c shows a side view of the paddle rail 20. The paddle rail 20 comprises a paddle holder 21, on which, in the exemplary embodiment shown, there are arranged three wedge-shaped paddles 30, as described above in relation to FIGS. 1a to 1c. The paddle holder 21 has four fastening means 23, which are configured as bores and by means of which the paddle rail 20 can be fastened, for example, on a mixer shaft 10 (see FIG. 3a). A respective scraper 40 is arranged on each of the three paddies 30 and is embodied at both ends with a respective connecting means 41. The scraper 40 is in this case fitted on the paddle 30 on the back face 34 (see FIG. 1c). It goes without saying that the scrapers 40 can have different configurations, depending on the application. In particular, the scrapers 40 can also have different configurations at the ends thereof in the region of the connecting means 41. By way of example, they can also have a straight configuration and be bent by an angle of approximately 90 only in the end region. The paddles 30 are introduced with their fastening means 32 (see FIG. 1a) into corresponding receiving positions (not shown) of the paddle holder 21, where they are accordingly welded. In this respect, the paddles 30 are arranged in such a manner that, during intended use of the paddle rail 20, the paddies 30 are arranged with their back face 34 or with the scraper 40 on a plane perpendicular to the axis of rotation 11 of a mixer shaft 10 (see FIG. 3a). Each of the paddles 30 is provided with an opening 35, this running proceeding from the working face 33 to the back face 34 (see FIG. 1).

(37) FIG. 2d schematically shows two paddle rails 20, each comprising a paddle holder 21 and a paddle 30. The paddle holders 21 are in each case formed with a substantially u-shaped cross section, are arranged around a mixer shaft 10 and are connected to one another. A frictional connection serves for transmitting the torque.

(38) Alternatively, the mixer shaft 10 can be in the form of a square profile, as shown in FIG. 2e. The paddle holders 21 are formed with a corresponding cross section. In this case, the torque is transmitted by means of a form fit.

(39) FIG. 2f shows a paddle 30 having two scrapers 40, which are connected to one another and to the paddle 30 by means of connecting means 41. In this way, only one connecting means 41 is required for fastening the scrapers 40 on the paddle 30.

(40) FIGS. 3a and 3b show a plan view of a mixer shaft 10 according to the invention and, respectively, a perspective view of the mixer shaft 10. A plurality of paddles 30 (as described above) are arranged, on the mixer shaft 10. These paddles 30 are located in an initial region 12 of the mixer shaft 10. Yet further mixing paddles 14 of differing configurations are arranged adjacent to this initial region 12. The paddles 30 are respectively connected to one another with the corresponding scrapers 40. In addition, the individual paddles 30 are arranged on a respective paddle holder 21. The paddles 30, the scrapers 40 and the paddle holder 21 together form a paddle rail 20 which can be exchanged easily when required. During intended use, the mixer shaft 10 rotates about the axis of rotation 11.

(41) FIGS. 4a and 4b show a mixer 1 according to the invention, FIG. 4a showing a plan view and FIG. 4b showing a perspective view of the mixer 1 with an open housing wall 2. The mixer 1 has an inlet 15 and an outlet 16. In an initial region 12 of the mixer 1, the mixer shaft 10 arranged inside the mixer 1 is provided with wedge-shaped paddles 30, as described above. These wedge-shaped paddies 30 ensure that the product introduced into the mixer 1 is mixed and conveyed in one direction of rotation R (see FIG. 1a), while the product is merely mixed upon rotation of the mixer shaft 10 in an opposite direction R. The individual paddles 30 are in each case connected to one another via scrapers 40. In this case, the paddles 30 are each arranged on a paddle holder 21. The ends of the scrapers 40 are provided with connecting means 41, which allow for the connection to a subsequent scraper 40. It can also be seen in FIG. 4a that the wedge-shaped paddies 30 have a mixing face 38 on the side counter to the direction of rotation R (see FIG. 1a), while a cutting edge 37 is arranged on the other side.

(42) A mixer 1 of this type can then be filled at least partially with a product to be mixed via the inlet 15 during start-up, for example. Then, the mixer shaft 10 can be rotated in such a manner that the mixing faces 38 of the paddies 30 mix the product to be mixed. Only when the product to be mixed has reached the desired consistency, for example by charging with steam and/or by heating, is it possible for the direction of rotation of the mixer shaft 10 to be changed, such that the individual paddles 30 mix the product to be mixed with the working face 33 thereof and at the same time convey said product in the direction of the outlet 16. If necessary, the direction of rotation of the mixer shaft 10 can be changed once again, if the product to be mixed and to be conditioned does not yet satisfy the necessary conditions.