WO2004105966A1

WO2004105966A1 - Apparatus and method to separate materials having different granulometry

Info

Publication number: WO2004105966A1
Application number: PCT/IB2004/001748
Authority: WO
Inventors: Adriano Stocco
Original assignee: Instalmec Srl
Priority date: 2003-05-30
Filing date: 2004-05-28
Publication date: 2004-12-09
Also published as: ITUD20030119A1

Abstract

Apparatus (10) and method to separate an incoherent mass of material (13) according to the granulometry of the pieces that make up the mass. The apparatus (10) comprises a tank (12) provided with introduction members (16, 17) to feed the material (13) to be separated, and with first collection elements (20, 21) which collect the fine material having a granulometry equal to or less than a predetermined value. The material (13) introduced into the tank (12) moves from the introduction members (16, 17) to the first collection elements (20, 21) along a substantially longitudinal main flow. Inside the tank (12), between the introduction members (16, 17) and the first collection elements (20, 21), transverse to the main flow, separation members (14, 15) are arranged, through which only the fine material passes. The separation members comprise a rotatable separation element (14, 15) which rotates around a longitudinal axis of the tank (12), inside which, in correspondence with the rotatable separation element (14, 15), removal elements (40, 41) are arranged, which remove the material (13) having a granulometry greater than the predetermined value, generating a secondary flow of air directed in the opposite direction to the main flow.

Description

"APPARATUS AND METHOD TO SEPARATE MATERIALS HAVING

DIFFERENT GRANULOMETRY"

* * * * *

FIELD OF THE INVENTION The present invention concerns an apparatus, and the relative method, to separate an incoherent mass of material according to the granulometry of the individual pieces, consisting for example of sawdust, chips, shavings or otherwise, preferably but not exclusively derived from working waste in plants that process wood or similar materials .

BACKGROUND OF THE INVENTION An apparatus is known to separate woody material according to the granulometry of the pieces that make it up and arriving from a processing plant, separating it from possible foreign bodies of different type, such as for example pieces of glass, metal or plastic, in order to obtain a mixture of material of homogeneous size and suitable to be re-used in the production of panels or otherwise.

The known-type apparatus comprises a tank, arranged vertically, into which the material to be separated is introduced from above and the separated material is removed from a lower aperture associated with a suction pump. Inside the tank a depression is thus generated which facilitates the fall of the material downwards. Moreover, in the intermediate zone of the tank a separation grid is arranged, through which only the fine material can pass, with a granulometry equal to or less than a predetermined value, defined by the size of the mesh of the grid.

The large pieces of material, with a granulometry greater than that of the predetermined value, are removed manually, or by mechanical means, through a lateral aperture made on the tank above the separation grid.

This known separation apparatus has the disadvantage, however, that in order to remove the larger material, from the upper wall of the separation grid, through the lateral aperture, due to the depression existing inside the tank, a secondary flow of air is generated coming from the lateral aperture itself, which contrasts the removal of the larger pieces of material and tends to interfere disadvantageously with the main flow of air, creating unwanted turbulence. Consequently, during the functioning of the known apparatus, the lateral aperture has to be opened only to remove the larger material but it is necessary to close it, thus stopping the removal of the material itself during the proper separation step. With the known apparatus, it is therefore difficult, if not impossible, to obtain a continuous separation of the mass of material introduced, especially when the quantity of material is large, since the material itself, as it accumulates on the separation grid, impedes the separation of the material with a finer granulometry.

Moreover, there is the disadvantage that, when the lateral aperture is opened to clean the separation grid, the suction pump has to be interrupted, in order to prevent the introduction of air from the lateral aperture. This entails an inevitable extension of the times required for the whole separation operation.

One purpose of the present invention is to achieve an apparatus and a relative method to efficiently separate a material with pieces of different granulometry, wherein it is possible to effect a continuous removal of the larger pieces of material retained on the separation element, without having to stop the functioning of the apparatus itself, and reducing to a minimum the risk of generating irregular and uncontrollable flows of air inside the tank.

Another purpose of the present invention is to achieve an apparatus to separate pieces of different sizes, also separating them from possible foreign bodies of different nature, wherein it is possible to continuously shake and jolt the pieces deposited on the separation element, so as to prevent the larger pieces from impeding the fall of the smaller ones.

The Applicant has devised, tested and embodied the present invention in order to achieve these and other purposes and advantages, and to overcome the shortcomings of the state of the art.

SUMMARY OF THE INVENTION The present invention is set forth and characterized in the main claims, while the dependent claims describe other characteristics of the present invention or variants to the main inventive idea .

An apparatus according to the present invention, to separate an incoherent mass of material according to the granulometry of the pieces that make up such mass, comprises a tank provided with introduction means to feed the material to be separated, and with first collection means able to collect the fine material with a granulometry equal to or less than a predetermined value. The material introduced into the tank is able to move from said introduction means to said first collection means along a substantially longitudinal main flow. Such main flow can be created through gravity, by arranging the tank vertically. Advantageously, the main flow is generated or encouraged by first suction means. Inside the tank, between the introduction means and the first collection means, separation means are arranged transverse to said main flow and through which only the material with a granulometry equal to or less than a predetermined value is able to pass. The separation means comprise at least a separation element rotatable around a longitudinal axis of the tank. Inside said tank, in correspondence with the separation element, removal means are arranged which are able to remove the material with a granulometry greater than said predetermined value, sending it towards second collection means, by generating a secondary flow of air which is directed in the opposite direction to the aforesaid main flow.

In one embodiment of the invention, the tank is substantially vertical, the introduction means are arranged in the upper part of the tank and the first collection means are arranged in the lower part of the tank, so that the main flow is directed from the top towards the bottom.

The removal means advantageously comprise second suction means, which by means of first conveyor means, arranged in determinate positions with respect to the separation element, create said secondary flow only in correspondence with a determinate static sector of said rotatable separation element .

In one embodiment of the invention, the rotatable separation element is arranged horizontal and the first conveyor means are above the rotatable separation element, in proximity to the latter and are connected to said second suction means . Second conveyor means are arranged below the rotatable separation element, in proximity to the latter and opposite the first conveyor means. In this way, the air of the secondary flow hits, from the bottom towards the top, the sector of the separation element that is transiting in an intermediate zone between the first and second conveyor means, without impeding the main flow of material. The removal of the material with a larger granulometry can thus be effected continuously and without having to interrupt the functioning of the apparatus .

Advantageously, the air of the secondary flow is clean, while the main flow can be obtained using process air.

In one embodiment of the invention, the means to introduce the material into the tank are able to introduce the material into a first longitudinal sector, to deposit it on a corresponding portion of the separation element, while the removal means are arranged in correspondence with a second longitudinal sector of the tank, angularly offset with respect to the first sector. To be more exact, with respect to the direction of rotation of the separation element, the introduction means are arranged before the removal means and are advantageously in correspondence with the beginning of a revolution of the separation element, while the removal means are in correspondence with the end of the revolution of the separation element. In this way an efficient separation of the material is ensured, so that at the end of one revolution, only the material with a greater granulometry is removed, and all the fine material has passed through the meshes of the separation element.

Shaker means are advantageously associated with said rotatable separation element in order to shake the material deposited therein, encouraging the fall of the material with fine granulometry.

Such shaker means advantageously comprise blower elements, able to blow air upwards through said rotatable separation element in order to move and jolt said material. According to a variant, these shaker means comprise for example vibration means which make the rotatable separation element vibrate .

In one embodiment of the invention, the blower elements are arranged in determinate static positions with respect to the tank, below the separation element and able to blow air upwards in order to shake, move and jolt the material deposited on the element itself, eliminating possible accumulations of material. Advantageously, the blower elements are arranged angularly offset with respect to each other, between the first longitudinal sector, where the material is introduced, and the second longitudinal sector where said removal means are arranged. BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein:

- fig. 1 is a partly sectioned side view of an apparatus according to the present invention;

- fig. 2 is a partly sectioned detail of the apparatus in fig. 1; - fig. 3 is a section along the line III-III of fig. 1;

- fig. 4 is a section along the line IV-IV of fig. 1;

- fig. 5 is a section along the line V-V of fig. 1;

- fig. 6 is a section along the line VI-VI of fig. 1;

- fig. 7 is a section along the line VII-VII of fig. 1. DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT

OF THE INVENTION Fig. 1 shows an apparatus 10 according to the invention to separate an incoherent mass of material 13 according to the granulometry of the pieces that make it up, such as chips, granules, shavings or otherwise, also separating it from possible foreign bodies of other nature. The apparatus 10 comprises a tank 12 substantially cylindrical in shape, of a large size, for example with a diameter of about 2 m and a height of about 4 m. A loading member 16, consisting for example of a screw, is arranged in the upper zone of the tank 12 and is able to feed from above, and continuously, the material 13 through a feed pipe 17 which in this case is curved and shaped inside like a chute .

The tank 12 is connected in the lower zone, by means of a pipe 22, to a suction pump 18 which takes in air from the top towards the bottom, creating a main descending flow which transports the material 13 with it, encouraging it to fall into the tank 12. The air is sucked in through an aperture 23 made in the upper zone of the tank 12.

The material 13 is collected in the bottom zone of the tank 12 through a first and second mouth 20, 21 and transported outside the tank 12 by the suction pump 18.

Inside the tank 12, between the loading member 16 and the suction pump 18, a first grid 14 and a second grid 15 are arranged in a horizontal position one above the other, able to separate the material introduced. It is clear that the number of grids used is not restrictive for the present invention, and can vary according to the type of separation to be made .

Both grids 14 and 15 comprise a supporting frame 19 consisting of an outer metal ring 19a (figs. 2 and 4), an inner collar 19b and a plurality of radial spokes 19c arranged in radiating manner and which connect the inner collar 19b to the outer metal ring 19a. The supporting frame 19, thus configured, defines between the spokes 19c a plurality of distinct radial sectors, in correspondence with each of which a portion of net with meshes 11 is stretched in order to separate the material. To be more exact, the net 11 is attached to the respective spokes 19c and to the outer ring 19a by means of attachment means of a known type and not shown in the drawings .

Thanks to this configuration, in sectors, the grids 14, 15 are resistant enough to support the whole load of material introduced. Moreover, each portion of the net 11 can be removed from the frame 19 independently of the others, for possible repairs or replacements .

The net 11 attached to the frame 19 of the first grid

14 has a wider mesh than that of the net of the second grid 15, in order to retain a first fraction of material 13 with a greater granulometry than that of the intermediate granulometry which is retained on the second grid 15.

According to a characteristic of the present invention, both the first grid 14 and the second grid 15 are keyed in correspondence with the inner collar 19b onto a longitudinal shaft 24 mounted rotatable inside the tank 12, which is driven by a ratio-motor 26 (fig. 1) arranged on an upper wall 27 of the tank 12. In this case, the grids 14, 15 are made to rotate continuously and in clockwise direction inside the tank 12.

The outer ring 19a of each grid 14, 15 is able to slide, in this case, in a circular recess 30 (figs. 1 and

2), made inside a cylindrical wall 31 of the tank 12 and in which rollers 32 are mounted which facilitate and support the rotation of each grid 14, 15.

According to a variant, the rollers 32 can be replaced by pads or other elements with a low friction coefficient.

According to another characteristic of the present invention, in correspondence with each grid 14, 15, removal units 40, 41 are arranged (figs. 1, 5 and 6), each of which is able to remove the pieces of material 13 which are retained by the relative grid 14, 15. To be more exact, each removal unit 40, 41 removes the material by generating a secondary flow of air directed in the opposite direction to the main flow of air and sends it towards collection containers, of a known type and not shown in the drawings. In this case, each removal unit 40, 41 comprises a suction pump 42, which takes in air from the bottom towards the top through two pipes 43 and 45, which are arranged in static positions respectively below and above a corresponding radial portion of each grid 14, 15.

In this way, the secondary flow of air continuously transports the larger material away, without it being necessary to stop the suction of the pump 18.

Each pipe 43 and 45 is provided in correspondence with respective terminal portions 46 and 47, arranged in proximity to the corresponding grid 14, 15, with an aperture for the passage of air, big enough to take in all the material retained. The arrangement of the two terminal portions 46 and 47 in proximity to the corresponding grid 14, 15 allows ^• to keep the secondary flow of air substantially isolated from the main flow, preventing the formation of turbulence.

According to another characteristic of the present invention, both the first removal unit 40 and the second removal unit 41 are arranged dis-aligned inside the tank 12 with respect to the position of the feed pipe 17. To be more exact, the feed pipe 17 is arranged in a first longitudinal sector 50, indicated by a line of dashes in figs. 3 and 5, inside the tank 12 and extends downwards as far as in proximity to the first grid 14, so as to pour the material 13 onto a corresponding radial portion of the first grid 14.

The first removal unit 40, on the contrary, is arranged in a second longitudinal sector 51, shown by a line of dashes in fig. 5, which is arranged angularly offset and, in this case, positioned downstream with respect to the first longitudinal sector 50, so that, during its rotation around the shaft 24, the first grid 14 transits at the start of a revolution in correspondence with the feed pipe 17 and, after an almost complete revolution, transits in correspondence with the first removal unit 40.

The offset arrangement of the removal unit 40 with respect to the feed pipe 17 allows to obtain, when the revolution of the grid 14 is completed, a sufficient separation of the material with a granulometry smaller than the diameter of the holes of the first net 11 from the larger material, before the latter is removed.

The material with a smaller granulometry then descends, substantially in a shower, onto the second grid 15, where the very fine material, in the order of a few millimeters, is separated from the material of greater granulometry, which is retained and removed by the second removal unit 41. In the embodiment shown here, the second removal unit 41 is also arranged offset with respect to the first removal unit 40, by about 15° (fig. 6) .

In the bottom zone of the tank 12 only very fine material is collected through the mouths 20, 21. To be more exact, in order to facilitate the conveyance of the material through the relative mouths 20, 21, a pair of conveyor blades 60 is provided (figs. 1 and 7), each of which is keyed to the shaft 24 and allows to keep the bottom of the tank 12 clean. To further improve the separation of the material, below each grid 14, 15 a blower unit 53 is mounted (figs. 1, 2, 5 and 6), able to move and jolt the material 13 deposited therein. The blower unit 53 comprises a plurality of pipes 55 mounted in radiating manner in determinate static positions, holed in the upper part, in order to allow the passage of air upwards. The pipes 55 are connected in this case to a single ventilator 58, by means of a corresponding outer common chamber 56, which surrounds the cylindrical wall 31 of the tank 12 (figs. 5 and 6). The material 13 that is deposited and that does not pass through the grids 14, 15, thanks to the rotating movement of the grids 14, 15, transits in correspondence with each pipe 55 and is made to jolt. In this way the transit of possible material with a granulometry smaller than the diameter of the holes in the grids 14, 15 and which has been blocked between larger pieces of material .

It is clear, however, that modifications and/or additions of parts may be made to the separation apparatus 10 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to specific examples, a skilled person in the art shall certainly be able to achieve many other equivalent forms of separation apparatus, all of which shall come within the field and scope of the present invention.

Claims

1. Apparatus to separate an incoherent mass of material according to the granulometry of the pieces that make up said mass, comprising a tank (12) provided with introduction means (16, 17) to feed the material (13) to be separated, and first collection means (20, 21) able to collect the fine material having a granulometry equal to or less than a predetermined value, wherein the material (13) introduced into said tank (12) is able to move from said introduction means (16, 17) to said first collection means

(20, 21) along a substantially longitudinal main flow, and wherein inside said tank (12), between said introduction means (16, 17) and said first collection means (20, 21), transverse to said main flow, separation means (14, 15) are arranged, through which only said fine material is able to pass, characterized in that said separation means comprise at least a rotatable separation element (14, 15) which rotates around a longitudinal axis of said tank (12), in that inside said tank (12), in correspondence with said rotatable separation element (14, 15), removal means (40, 41) are arranged, able to remove the material (13) having a granulometry greater than said predetermined value, generating a secondary flow of air directed in the opposite direction to said main flow, and in that first suction means (18) are provided to generate, or facilitate, said main flow.

2. Apparatus as in claim 1, characterized in that said tank (12) is substantially vertical, that said introduction means (16, 17) are arranged in the upper part of said tank (12) and that said first collection means (20, 21) are arranged in the lower part of said tank (12) .

3. Apparatus as in claim 1 or 2 , characterized in that said removal means (40, 41) comprise second suction means (42) able to suck in the material retained on said rotatable separation element (14, 15) through first air conveyor means (45), which are arranged in a static position with respect to said tank (12) above and in proximity to a sector of said rotatable separation element (14, 15) .

4. Apparatus as in claim 3, characterized in that said removal means (40, 41) comprise second air conveyor means (43), which are arranged below and in proximity to said rotatable separation element (14, 15) and aligned with said first air conveyor means (45), and in that said second suction means (42) are able to suck in air from the bottom upwards through said second (43) and said first (45) air conveyor means, hitting the sector of said rotatable separation element (14, 15) which is transiting in an intermediate zone between said first (45) and said second (43) air conveyor means.

5. Apparatus as in claim 4, characterized in that said first and said second air conveyor means comprise respective pipes (43, 45) having terminal portions (46, 47) open towards said rotatable separation element (14, 15) .

6. Apparatus as in any claim hereinbefore, characterized in that said introduction means (16, 17) are able to introduce said material (13) in a first longitudinal sector (50) of said tank (12) in order to deposit it on a corresponding sector of said rotatable separation element (14, 15) .

7. Apparatus as in claim 6, characterized in that said removal means (40, 41) are arranged in correspondence with a second longitudinal sector (51) of said tank (12), which is angularly offset with respect to said first longitudinal sector (50) .

8. Apparatus as in claim 7, characterized in that said first longitudinal sector (50) is arranged, according to the direction of rotation of said rotatable separation element (14, 15) , in front of said second longitudinal sector (51), so that every portion of said rotatable separation element (14, 15) is able to transit in a first moment in said first longitudinal sector (50) in order to allow the depositing of the material (13) to be separated, and subsequently is able to transit in said second longitudinal sector (51) in order to allow the removal of said material (13) retained.

9. Apparatus as in any claim hereinbefore, characterized in that said rotatable separation element comprises a grid

(14, 15) formed by a plurality of radial sectors, in correspondence with each of which a net with meshes (11) is attached.

10. Apparatus as in claim 9, characterized in that said grid (14, 15) comprises a supporting frame (19) for said net with meshes (11), wherein said frame (19) comprises a plurality of spokes (19c) arranged in radiating manner and attached between an inner collar (19b) and an outer metal ring (19a) , coaxial to the axis of rotation.

11. Apparatus as in any claim hereinbefore, characterized in that on the inner wall of said tank (12), in correspondence with said rotatable separation element (14, 15), a circular recess (30) is made in which a peripheral portion of said rotatable separation element (14, 15), provided with rolling means (32), is able to slide.

12. Apparatus as in any claim hereinbefore, characterized in that said rotatable separation element (14, 15) is associated with shaker means (53), able to shake the material (13) deposited therein.

13. Apparatus as in claim 12, characterized in that said shaker means comprise blower elements (53), able to blow air upwards through said rotatable separation element (14, 15) in order to move and jolt said material (13) .

14. Apparatus as in claim 13, characterized in that said blower elements (53) comprise a plurality of pipes (55) mounted below said rotatable separation element (14, 15) , which are holed in the upper part in order to allow the passage of air, and are connected to corresponding ventilator means (58) .

15. Apparatus as in claim 14, characterized in that said pipes (55) are arranged in determinate static positions with respect to the tank (12) and in radiating manner.

16. Apparatus as in claims 8 and 13, characterized in that said blower elements (53) are arranged in a zone between said first longitudinal sector (50) and said second longitudinal sector (51).

17. Apparatus as in claim 14 or 15, characterized in that said ventilator means comprise a single ventilator member

(58) which is connected to said pipes (55) by means of a common chamber (56) to distribute the air, arranged outside said tank (12) .

18. Method to separate an incoherent mass of material, according to the granulometry of the pieces that make up said mass, in a tank (12) wherein on one side material (13) to be separated is introduced, and on the other side the fine material having a granulometry equal to or less than a predetermined value is collected, wherein the material (13) introduced into said tank (12) moves along a substantially longitudinal main flow from one side to the other of said tank (12), and wherein inside said tank (12) a separation element (14, 15) is provided, arranged transverse to said main flow and through which only said fine material passes while the material having a granulometry greater than said predetermined value is retained, characterized in that said separation element (14, 15) rotates around a longitudinal axis of said tank (12) and transits in correspondence with removal means (40, 41) which, generating a secondary flow of air directed in the opposite direction to said main flow, send the material retained on said rotatable separation element (14, 15) towards second collection means .

19. Method as in claim 18, characterized in that the air of the secondary flow is sucked in by suction means (42), which convey it from the bottom upwards, hitting a corresponding sector of said rotatable separation element (14, 15), through respective conveyor means (45, 43).

20. Method as in claim 19, characterized in that the air of the secondary flow is sucked in from outside said tank (12) .

21. Method as in claim 18, 19 or 20, characterized in that, in said tank (12), the material (13) is introduced in a first longitudinal sector (50) of said tank (12) to be deposited on a portion of said rotatable separation element (14, 15) and, following the rotation of said rotatable separation element (14, 15), said portion of said rotatable separation element (14, 15) transits in correspondence with a second longitudinal sector (51) where said removal means (40, 41) are arranged to remove the material (13) retained.

22. Method as in any claim from 18 to 21 inclusive, characterized in that the material retained on said rotatable separation element (14, 15), before being removed, is jolted by shaker means (53) which shake the material (13) deposited on said rotatable separation element (14, 15) .

23. Method as in claim 22, characterized in that said material (13) is jolted by air that is blown upwards from a lower zone of said rotatable separation element (14, 15) .