Abstract
A system and a method for packaging compacted powders are provided, wherein the system comprises a first tube (TC), wherein a screw conveyor (C) is positioned inside the first tube (TC) which is configured so as to rotate around an axis (ac) inside the first tube (TC) in order to convey the powders towards an outlet (UT) of the first tube (TC); the system (100) comprises a rotatable terminal (TI, TIC) in the proximity of the output (UT); the rotatable terminal (TI, TIC) comprises in its inside cutting means (F) which are configured so as to cut the compacted powders leaving the first tube (TC) when the rotatable terminal (TI) rotates, wherein the rotatable terminal (TI, TIC) is positioned so as to contact the end of the first tube (TC) which defines the output (UT).
Claims
1. A compacted powders packaging system, comprising: a first tube, wherein said first tube comprises a screw conveyor configured to rotate about an axis inside said first tube so as to convey powders towards an outlet of said first tube, wherein said system comprises a rotatable terminal in proximity to said outlet; said rotatable terminal comprising internal cutting means configured to cut compacted powders going out from said first tube when said rotatable terminal rotates, wherein said rotatable terminal is positioned so as to contact the end portion of said first tube which defines said outlet; wherein said rotatable terminal includes an internal opening which is concentric with said first tube so as to convey the powders through said internal opening; wherein said internal cutting means are positioned within said internal opening; wherein said internal opening has a diameter at said outlet of said first tube which is equal to the inner diameter of said first tube at said outlet; and wherein said internal opening of said rotatable terminal is of conical or truncated cone shape; wherein an axis of said conical or truncated cone shape coincides with the axis of said screw conveyor.
2. The compacted powders packing system according to claim 1, wherein: said first tube is placed inside a second tube; wherein said second tube is rotatable around said first tube; and wherein said rotatable terminal is connected to said second tube so as to rotate with said second tube.
3. The compacted powders packing system according to claim 2, wherein: said first tube and said second tube are concentric.
4. The compacted powders packing system according to claim 2, wherein: said rotatable terminal comprises a ring structure, which is detachably connected to said second tube so as to be able to rotate with said second tube, wherein said cutting means are connected to said ring structure.
5. The compacted powders packing system according to claim 1, wherein: said cutting means comprise a plurality of wires arranged in a radial pattern.
6. The compacted powders packing system according to claim 5, wherein: the center of said radial pattern coincides with the axis of said first tube.
7. The compacted powders packing system according to claim 1, further comprising: a vertical packaging machine comprising a forming tube configured to accommodate a film coming from a reel; wherein said forming tube contains said first tube inside said forming tube.
8. The compacted powders packing system according to claim 7, wherein: said first tube and said forming tube are concentric.
9. The compacted powders packing system according to claim 2, further comprising: a forming tube containing said first tube; wherein said forming tube has an opening configured to insufflate gas into a gap between said forming tube and said second tube.
10. The compacted powders packing system according to claim 9, wherein: said opening is positioned in proximity to an upper edge of said forming tube.
11. The compacted powders packing system according claim 2, further comprising: a vertical packaging machine comprising a forming tube configured to accommodate a film coming from a reel; and wherein said forming tube contains said second tube inside said forming tube.
Description
BRIEF DESCRIPTION OF THE FIGURES
(1) The present invention will be described with reference to the attached figures in which the same reference numerals and/or marks indicate the same parts and/or similar and/or corresponding parts of the system.
(2) FIG. 1 schematically shows a system for packaging compacted powders in three-dimensional view according to an embodiment of the present invention;
(3) FIG. 2 schematically shows the cross-section of a powder packaging system according to an embodiment of the present invention;
(4) FIG. 3 schematically shows a system for packaging compacted powders in three-dimensional view according to an embodiment of the present invention;
(5) FIG. 4 a, b, c, d, and e schematically show different versions of the rotatable terminal according to various embodiments of the present invention;
(6) FIG. 5 schematically shows the cross-section of a powder packaging system at the moment when the plant is filled with powders according to an embodiment of the present invention;
(7) FIG. 6 schematically shows the initial phase of filling a package in a powder packaging system according to an embodiment of the present invention;
(8) FIG. 7 schematically shows the step of stopping the screw conveyor in a semi-filled package status in a powder packaging system according to an embodiment of the present invention;
(9) FIG. 8 shows a three-dimensional view of the step of stopping the screw conveyor in the semi-filled package status in a powder packaging system according to an embodiment of the present invention;
(10) FIG. 9 is a three-dimensional view of stopping the screw conveyor in the semi-filled package status in a powder packaging system according to an embodiment of the present invention;
(11) FIG. 10 shows a three-dimensional view of the rotation phase of the second tube to which the rotatable terminal is fixed according to an embodiment of the present invention;
(12) FIG. 11 shows a three-dimensional view of the completion of the package by welding and shearing and the beginning of the filling of a new package according to an embodiment of the present invention;
(13) FIG. 12 shows a three-dimensional view of the opening of the forming tube and the introduction of gas inside it according to an embodiment of the present invention.
DETAILED DESCRIPTION
(14) Hereinafter, the present invention is described with reference to particular embodiments, as illustrated in the attached tables of drawings. However, the present invention is not limited to the particular embodiments described in the following detailed description and represented in the figures, but rather the described embodiments simply exemplify the various aspects of the present invention, the purpose of which is defined by the claims. Further modifications and variations of the present invention will become clear to those skilled in the art.
(15) FIG. 1 schematically shows a system for packaging compacted powders 100 according to an embodiment of the present invention. As shown in the figure, the powder packaging system 100 comprises a hopper T having an inlet TP through which powders are conveyed inside the hopper T. In the lower part of the hopper T is placed a screw conveyor C which, due to the rotation around its own axis ac, conveys the powders inside a tube positioned in the lower part of the hopper T and through which the powders are conveyed.
(16) FIG. 2 schematically shows a section of the lower part of the compacted powder packaging system 100 presented in FIG. 1. The screw conveyor C is contained inside a first TC tube through which the powders coming from the hopper T reach the outlet of the first tube TC. Near the output UT of the first tube TC there is a rotatable terminal T1 which comprises cutting means F.
(17) The rotatable terminal T1, which is cylindrical in shape, comprises a concentric inner opening AP with the first TC tube so as to convey the powders through it. Furthermore, the cutting means F are positioned inside said opening AP.
(18) The first TC tube is inserted inside a second tube TR. In this way, a gap is formed between the outer region of the first tube TC and the inner region of the second tube TR. The second tube TR is rotatable around the first tube TC. This rotation is guaranteed, as shown in FIG. 3, by a lever LC which is connected to an upper flange FS positioned in the upper part of the second tube TR. The second tube TR is connected to the rotatable terminal T1 so as to transmit the rotation to the terminal T1. This connection is guaranteed, for example, by a mechanical constraint.
(19) The axes of the first tube TC and of the second tube TR coincide. Between the first tube TC and the second tube TR, a centring ring AO is positioned which ensures that the second tube TR is always centered with respect to the first tube TC. Such an element can be made, for example, of plastic, brass or bronze material which has reduced friction coefficient in order to help sliding between the tubes.
(20) The cutting means F, represented in FIG. 3, are represented by two wires arranged perpendicular to one another in a fan so as to form an angle of 90° between them. In this way, by rotating such cutting means F by 90° the same starting configuration is obtained since a wire will have taken the place occupied by the other wire before the rotation. Moreover, the number of wires, their section and the dimensions are selected as a function of the type of powder to be dosed and of the degree of compacting of such a powder. For example, the cutting means F can also be made up of 5, 6 or even more wires. In the case in which there are four wires, the resulting angle between one wire and the other will be 45°. Such wires can be replaced, for example, by blades or by knives that are installed in an analogous manner to the wires. The wires are made from a strong material suitable for contact with food products like, for example, stainless steel. Moreover, it is also possible to use a food-grade plastic like fishing line which makes it possible to have very low thicknesses and despite this have great mechanical strength.
(21) The cutting means F can also be formed from a grid having a plurality of openings. In this way, it is thus possible to have cutting means F consisting of multiple wires arranged woven together and forming a plurality of openings having any shape and size.
(22) In the manufacturing step, the cutting means F can also be made by removal of material from a lower terminal TI initially without cavities. In this case, through mechanical processing, it is possible to remove material so as to form the wires in this case having a square section.
(23) The center of the fan of wires coincides with the axis of the first tube TC and thus consequently with the axis of the screw conveyor ac. The system thus obtained, as described having central symmetry, has cutting means positioned at the center of the first tube TC.
(24) As can be seen in FIGS. 4a-4e, which schematically show different versions of the rotatable terminal according to various embodiments of the present invention, the rotatable terminal is positioned in contact with the outlet of the first tube TC so that there is no space between the outlet of the first tube TC and the rotatable terminal TI in which the powders can be inserted. In this way, the powders going out from the first tube TC will be conveyed directly into the rotatable terminal TI. In this way, the cutting means F of the rotatable terminal will directly cut the powders leaving the first tube TC.
(25) Moreover, as can be seen in FIGS. 4a-4e, the rotatable terminal has a ring structure to which the cutting means are fixed. The opening AP of the ring of the rotatable terminal has, in each of the examples shown, an upper diameter (that is, the diameter of the opening AP at the outlet of the first tube TC) equal to the diameter of the first tube TC at the outlet. This therefore allows the powders leaving the first TC tube to be conveyed inside the rotatable terminal without obstacles. In fact, in the case where, for example, the upper diameter of the opening AP of the rotatable terminal is smaller, it would form a step that would hinder the conveyance of the powders.
(26) The opening AP of the rotatable terminal TI, as shown in FIG. 4a, has a cylindrical shape, thus having a constant section along the vertical axis. Such a constant section has a diameter equal to the inner diameter of the first tube TC. According to the solution represented in the figures, the length of the first tube TC is less than that of the second tube TR. Between the end part of the second tube TR and the end part of the first tube TC, the rotatable terminal is installed that is fixed to the second tube TR. Alternatively, as represented in FIG. 4c the length of the two tubes can be the same and the rotatable terminal TI′ can be installed below the lower edge of the two tubes.
(27) Alternatively, the opening AP of the rotatable terminal TIC, as shown in FIG. 4b, has a frusto-conical shape, thus having a converging section along the vertical axis: the upper part close to the outlet of the first tube TC has a diameter equal to the inner diameter of the first tube TC whereas the lower part has a smaller diameter than the upper part. The opening angle α of the cone can be adjusted depending on the degree of compacting and the type of material to be conveyed. According to the solution represented in the figures, the length of the first tube TC is less than that of the second tube TR. Between the end part of the second tube TR and the end part of the first tube TC the rotatable terminal TI is installed which is fixed to the second tube TR. Alternatively, as represented in FIG. 4d, the length of the two tubes can be the same and the rotatable terminal TI′C can be installed below the lower edge of the two tubes. The frusto-conical shape of the opening AP of the rotatable terminal TI′C is advantageous since it makes it possible to further compact the powder to be dosed even in the horizontal direction, in particular contributing to eliminating the possible central cavity in the volume of powder compacted due to the central region of the screw conveyor. Moreover, the frusto-conical shape makes it possible to facilitate the alignment between the product and the package to be filled.
(28) A further variant, shown in FIG. 4e, makes it possible to combine the advantages described above of having a cylindrical opening with those of having a conical opening. As shown in the figures, the first tube TC is in this case replaced by a first tube TC″ having a frusto-conical shape at its lower end. Therefore, with such a frusto-conical portion, it is in this way possible to obtain a further compacting of the powders as described above. Downstream of said conical portion, there is the rotatable terminal TI having an opening AP that has a cylindrical shape. In this case, the rotatable terminal TI is integrated directly in the centring ring AO, so as to form a single element.
(29) As shown in FIG. 1, the packaging system 100 further comprises a vertical packager which comprises a forming tube TF to make it possible to receive a film coming from a reel B. Like all vertical packagers, also in this case, there is a vertical welder (not represented in FIG. 1) that allows the vertical welding of the packages and there are members (not present in FIG. 1) capable of making the film slide towards the lower part of the forming tube TF. The forming tube TF internally contains the second tube TR and consequently also the first tube TC. Therefore, a gap is thus formed between the second tube TR and the forming tube TF. Moreover, the axis of the forming tube TF coincides with the axis of the first tube TC.
(30) As shown in FIG. 12, in the upper part of the forming tube TF, there is at least one opening AZ from which gas can be introduced inside the gap formed between the forming tube TF and the second tube TR. In addition or alternatively, an opening (not represented in the figures) can also be made on the outer upper surface of the second tube TR, for example, above the upper flange FS.
(31) Moreover, the second tube TR can be replaced by any other structure capable of connecting the rotatable terminal TI with the upper flange FS, like, for example, a grid. In this case the two aforementioned gaps will communicate. An alternative is represented by a system of rods capable of mechanically connecting the rotatable terminal TI with the upper flange FS or by a tube machined inside it.
(32) Hereinafter, with reference to FIGS. 5 to 12, the operative steps of the system shown in FIG. 3 are described and a method for packaging powders based on a particular embodiment of the present, invention is thus described.
(33) FIG. 5 represents the initial step of feeding the first tube TC with the compacted powders. The vertical packager slides the film coming from the reel B downwards, welded longitudinally and arranged on the outer surface of the forming tube TF. Such a film slides to the outlet of the forming tube TF so as to form a tubular element TS that in a second step, after filling a welding closed, will form the package. As shown in the figures, the tubular element TS is welded at the bottom and such a process will however be described hereinafter.
(34) In a subsequent step, depicted in FIG. 6, the volumetric dosing of the screw conveyor C takes place. By rotating around its axis ac, it makes the required volumetric amount of compacted powders reach the tubular element. Since the powders are compacted homogeneously, the amount by weight of compacted powders arriving at the tubular element is therefore also known. In this step, as described earlier and as represented in the figures, there is only the movement of the screw conveyor C around its axis ac in the direction SRC represented in the figures, whereas all of the other moving members are stationary.
(35) In a subsequent step, represented in FIG. 7, after the required flow rate of compacted powders has reached the tubular element TS, the stopping of the screw conveyor C takes place. However, due to the high degree of compacting and/or due to the vacuum present inside the first tube TC a part RI of the compacted powders remains anchored to it and does not detach by gravity. The vacuum present inside the first tube TC is due to the fact that for the compacting of the powders, the air contained inside the powders is extracted thus forming a large depression area. Such a remainder RI can represent a significant weighing error in filling. Such an error is accentuated more for smaller packages.
(36) For this reason, it becomes necessary to cut the remainder RI of the compacted powders still anchored to the outlet. Therefore, as shown in FIG. 8, through the movement of the lever LC along the direction SRLC, it is possible to move the upper flange FS of the second tube TR so as to allow the second tube TR to rotate about its axis. The degrees by which the second tube TR is rotated depend on the number of wires or blades of the cutting means F used. Indeed, in order to cut the remainder RI effectively, it is necessary to rotate the cutting members F by an angle greater than or equal to the angular distance between two wires. In the case, for example, in which it concerns a single wire, the rotation will be equal to 180°, in the case of two wires the rotation will be equal to 90°, in the case of four wires it will be equal to 45°, and so on. As described previously the number of wires is dependent on the type of powders and on the degree of compacting and it can be changed depending on which materials are being used.
(37) In the embodiment depicted, the lever LC allows the rotation of the flange FS in both directions: clockwise and anti-clockwise. Therefore, in the case depicted it is possible, once cutting has been carried out, to return to the starting position. It is obvious to those skilled in the art that in the case in which it is wished to avoid the step of returning to the starting position the lever LC can be replaced with a system that allows the upper flange FS to rotate 360° like, for example, gear, rack or similar systems.
(38) FIG. 9 represents a detail of the remainder RI still anchored to the outlet of the first tube. Following the rotation by 90° of the second tube TR (represented in FIG. 10) and thus consequently the rotation of the rotatable terminal TI having cutting means F made up of two wires, the remainder is driven inside the tubular element TS so that the required amount of compacted powders is conveyed inside the tubular element TS.
(39) In the case described above, following the cutting process, the second tube TR is brought back into the position where it was before the rotation discussed above. Alternatively, it is also possible to proceed with a rotation in a first direction, then carry out the dosing step through the rotation of the screw conveyor C, and thereafter take the rotatable terminal TI to its original position by carrying out a second rotation in the opposite direction with respect to the first, represented by arrow SRTR illustrated in FIG. 10. In this way, the cutting would be carried out in the return step of the rotatable terminal TI. Therefore, the rotatable terminal TI will in this case be equipped with blades directed so as to be able to cut in the return step in the case in which blades have been selected as cutting means F. On the other hand, in the case in which they are cutting means F represented by wires, in this case, there is not the problem of the cutting direction since they can be used without distinction in both of the cutting directions.
(40) At this point, the tubular element TS is ready to be closed. Therefore, in a subsequent step, depicted in FIG. 11, the closing of the upper part of the tubular element TS takes place through welding, and therefore there is the formation of a package S. In carrying out the welding at the same time, both the lower part of the new tubular element TS is closed and the upper part of the old tubular element TS is closed, thus forming a package S. After the welding has been carried out, the package produced can be separated from the tubular element TS through shearing. Following the welding process and before the shearing process is carried out, it is already possible to fill the next tubular element TS since, as stated previously, with the welding the lower closure of the new tubular element TS is prepared. In particular, said processes can also be carried out simultaneously.
(41) As shown in FIG. 12, in order to make it possible to compensate for the depression contained inside the tubular element TS, it is possible to insert gas inside the gap formed between the second tube TR and the forming tube TF. In this way, it is thus possible to compensate for the air that is drawn from inside the tubular element TS through the various tubes. The compensation is particularly important for the formation of the tubular element TS, since expanding outwards, it draws air inside it through the tubes with which it is placed in communication. In the absence of such compensation, the package S could therefore be ruined.
(42) Moreover, in the case in which it is intended to prevent the contact of the compacted powders (which therefore have previously been removed of much of the air contained inside them) with an oxygen-rich atmosphere, it is possible to introduce inert gas, like, for example, nitrogen inside the opening AZ of the forming tube. In the case, for example, in which coffee is being handled, this solution is particularly advantageous since it is well known that it would be harmful for the coffee to be in contact with an oxygen-rich atmosphere, since the coffee could oxidise.
(43) The amount of gas to be inserted inside the opening AZ is adjusted according to what depression is created inside the tubular element TS during the unwinding step. Such a depression can indeed be different depending on the format of the package to be made and on the type of film used. Such adjustment can, for example, be carried out by means of a valve.
(44) Even if the present invention has been described with reference to the embodiments described above, it is clear to those skilled in the art that it is possible to make different modifications, variations and improvements to the present invention in light of the teaching described above and in the attached claims, without departing from the object and the scope of protection of the invention.
(45) For example, the shape of the rotatable terminal is not necessarily round. Similarly, the shape of the tubes is not necessarily round. Moreover, the step of cutting the package is not constrained to being carried out through mechanical shearing since it could, for example, be carried out by laser cutting.
(46) The method and the system for packaging powders described in the present invention makes it possible to package any type of powdered material in any field. An example of powdered material that can be packaged is flour or ground coffee, and more generally any type of powdered material present in the food industry. Another example is represented by powders used in the building trade, for example, lime. The first tube can, for example, be interchangeable so as to be able to be replaced to change the filtering fineness in the case in which there are big variations in the grain size of the powder to be packaged.
(47) Finally, fields that are deemed known by those skilled in the art have not been described in order to avoid needlessly excessively overshadowing the described invention.
(48) Consequently, the invention is not limited to the embodiments described above, but is only limited by the scope of protection of the attached claims.
