WO2007119254A1

WO2007119254A1 - Ballistic separator

Info

Publication number: WO2007119254A1
Application number: PCT/IT2006/000257
Authority: WO
Inventors: Danilo Molteni
Original assignee: Sgm Gantry S.P.A.
Priority date: 2006-04-18
Filing date: 2006-04-18
Publication date: 2007-10-25

Abstract

A ballistic separator (1) comprising a separation chamber (2) in which particles of material (22, 23, 24, 25) can be thrown towards a rotating drum (3) by a gas flow. The drum (3) is provided with a perforated shell (11) and is connected to at least one suction duct (10) suitable for generating a depression inside the drum (3). The invention also relates to a separation method of particles of heterogeneous material.

Description

BALLISTIC SEPARATOR

The present invention relates to a ballistic separator and particularly to an air ballistic separator that allows to separate heterogeneous materials comprising particles with different shape and size, mass and nature.

The known air ballistic separators comprise a separation chamber wherein a conveyor belt or a vibrating channel introduces a material to be separated. At the point of the fall, the material is subject to a thrust by an airflow having an inclined direction from the bottom to the top with a suitable angle. Such a thrust has the task of throwing the lighter portion beyond a barrier that may have various shapes, among which that of a drum being fixed or rotating in the direction of the throw of the light material, whereas the heavier material is only poorly influenced by the thrust action of the air and falls downward by effect of its own weight. Such known separators are effective when materials comprising particles of a very different mass are to be separated, however they prove to be poorly effective when heterogeneous materials having very different particles in terms of mass, shape and size are to be separated, such as for example the ground materials coming from the demolition of vehicles, commonly known as "car fluff.

A known system allowing to separate heterogeneous materials as the car fluff is that of the air ballistic separators offered by the Synmet company, based in the Netherlands. Such separators use a rotating drum system that contributes to the thrust produced by the air blown in the separation chamber in order to separate the incoming waste into different fractions. The separators with a single rotating drum allow to separate the light particles from the heavy particles of the incoming materials, while the separators with a double rotating drum allow to separate the materials into light, heavy and intermediate weight particles. These separators are provided with suction systems being arranged above the separation chamber in order to facilitate the separation of the lighter particles. However, these known separators are rather bulky and, in addition, they do not allow to separate from each other particles with a similar intermediate weight but having different shapes.

Object of the present invention is thus to provide a ballistic separator being free from the above mentioned drawbacks. Such an object is achieved with a ballistic separator, the main features of which are specified in the first claim and other features are specified in the subsequent claims.

Thanks to the generation, inside the rotating drum, of a depression zone interacting with the airflow that strikes the material introduced in the separator, it is possible to separate particles with a similar intermediate weight but having different shapes.

Another object of the present invention is to provide a method of separation of heterogeneous materials, allowing to separate particles having similar intermediate weight but different shapes. Such an object is achieved with a method, the main features of which are specified in claim 24 and other features are specified in the subsequent claims.

The main advantage of the separator and the method according to the present invention resides in the possibility of separating heterogeneous materials into light, heavy and intermediate weight particles, even by employing one drum only.

Another advantage of the separator and the method according to the present invention resides in that, thanks to the use of only one drum, the separation chamber is much more compact and consequently the size of the separator is smaller.

Further advantages and features of the ballistic separator and the separation method of heterogeneous materials according to the present invention will be evident to those skilled in the art from the following detailed and non-limiting description of an embodiment thereof with reference to the attached drawings wherin:

- Figure 1 shows a top view of the separator according to the present invention;

- Figure 2 shows a top view of the rotating drum of the separator of Figure 1 ; - Figure 3 shows a sectional view along plane IH-III of Figure 2;

- Figure 4 shows a first sectional view along plane IV-IV of Figure 1 ; and

- Figure 5 shows a second sectional view along plane IV-IV of Figure 1.

Figure 1 shows the ballistic separator 1 according to the present invention, which comprises in a known way a separation chamber 2, wherein a rotating drum 3 is arranged being driven by a motor 4 in order to rotate around a substantially horizontal axis. A conveyor 5, for instance a belt or a vibrating channel, introduces particles of the material to be separated into the separation chamber 2. In the separation chamber 2 there is also a nozzle 6 being arranged under the end of the conveyor 5. During operation, nozzle 6 blows gas, in particular air, into the separation chamber 2, throwing the particles of the material to be separated towards the rotating drum 3. The air is introduced into the separation chamber 2 by means of a blower 7 and reaches nozzle 6 through a delivery duct 8 being provided with flow-rate adjusting means 9, such as for example one or more air locks. The separation chamber 2 is also connected to a suction duct 10 through which the air flows back to blower 7, thus creating a closed circuit. The suction duct 10 is provided with flow-rate adjusting means 9 as well. Figure 2 shows that the rotating drum 3 includes a cylindrical shell 11 and a pair of flanges 12. Drum 3 is coaxially assembled on the suction duct 10 and is rotatable thereon by means of a pair of bearings inserted into flanges 12. The suction duct 10 is supported by means of lateral supports 13. During operation, drum 3 is rotated for example by means of a motor 4 which is coupled to a gearbox and a chain drive. As it can be seen in the enlarged detail of Fig. 2, the cylindrical shell 11 of drum 3 is suitably perforated in order to connect the suction duct 10 to the separation chamber 2. The portion of the suction duct 10 arranged inside drum 3 is provided with a suction opening 14, so that the air surrounding drum 3 may be sucked through the cylindrical shell 11 and sent to blower 7. Figure 3 shows that the suction opening 14 is surrounded by walls defining a funnel-shaped suction chamber 15 inside drum 3. In such a way only a portion of the cylindrical shell 11 is connected to the suction duct 10 through the suction opening 14. The suction chamber 15 can rotate around a substantially horizontal axis in order to vary the inclination of its frontal wall 15a and of its rear wall 15b according to the working conditions of separator 1 and of the features of the materials to be separated. The inclination of walls 15a and 15b can be varied according to a first deviation angle α greater than 10°. In addition, the suction chamber 15 contains one or more radial panels 16 hinged above the suction opening 14, which divide the volume of chamber 15 into several sectors and allow to adjust the direction and/or the flow-rate of the airflow entering the suction duct 10 through the suction opening 14. Thus, it is possible to adjust the value of the depression inside the suction chamber 15. In fact, the radial panels 16 can be rotated around horizontal axes independently from one another, in order to vary the configuration of the suction chamber 15. Depending on the inclination of the radial panels 16, the opening angle β of the suction chamber 15, that is the angle corresponding to the portion of shell 11 being connected to the suction duct 10, may vary, for instance, between 20° and 110°. The values of the depression inside the suction duct 10 are comprised between 490 and 2940 Pa, and between 390 and 1470 Pa in correspondence to shell 11 of drum 3. In a preferred embodiment, the radial panels 16 are three and are bent in order to form bulkheads 16a suitable for reducing or preventing the flow of air by rotating these panels in determinate positions (shown by broken lines).

Referring to Figure 4, it is seen that the rotation axis of drum 3 is transversally arranged with respect to the direction of the incoming material and of the airflow blown by nozzle 6, at a suitable distance from the end of conveyor 5 and nozzle 6. Nozzle 6, which is arranged under conveyor 5, blows the air pumped by blower 7 in a direction inclined upwards tangentially to shell 11 of drum 3, thus striking the particles of the material discharged by conveyor 5 inside chamber 2. The thrust pressure of the airflow coming out from nozzle 6 is, for example, comprised between 150 and 1960 Pa. The inclination of nozzle 6 with respect to a horizontal plane can be varied according to the operating conditions of separator 1 and to the features of the materials to be separated, for example, according to a second deviation angle γ wider than 30°. In addition, it is possible to adjust the opening area of nozzle 6, thus obtaining variable flow conditions. The upper portion 17 of the air-flow passes over drum 3 and reaches the upper wall 18 of the separation chamber 2. As the upper wall 18 is inclined towards the rear and lower portion of the separation chamber 2, the upper portion 17 of the airflow is deviated downward beyond drum 3 and towards the rear wall 19 of chamber 2. The lower portion 20 of the airflow is sucked into the suction chamber 15 through the perforated shell 11. Due to the depression inside the suction chamber 15, the intermediate portion 21 of the airflow follows, on the contrary, the perforated shell 11 for the whole opening angle β, with a partially turbulent motion. Figure 5 shows the behavior of the particles of the material to be separated according to the airflow inside the separation chamber 2. Conveyor 5 may introduce a heterogeneous material to be separated such as, for example, the car-fluff, wherein particles with different shape and weight are present. The material introduced into the separation chamber 2 is struck by the ascending airflow coming out from nozzle 6. The heavier particles 22, shown with a circle, are not subject to the pushing action of the airflow and fall substantially vertically into a first collection zone A in the separation chamber 2, which is arranged under the front portion of the drum 3. Particles 23 having an intermediate weight and a flat shape, shown with a rectangle in the drawing, such as for example the fragments of plastic materials, are strongly influenced by the sucking action produced by the suction chamber 15, thereby adhering to shell 11 of the rotating drum 3 along the whole opening angle β of the chamber 15. Beyond this angle, the sucking action of chamber 15 ends and such particles fall into a second collection zone B arranged under the rear portion of drum 3. Particles 24 having an intermediate weight and a non-flat shape, shown with a triangle in the drawing, are less influenced by the sucking action of chamber 15 and go beyond drum 3 being transported by the intermediate turbulent portion 21 of the airflow, then reaching a third collection zone C arranged behind the second collection zone B. Finally the lighter particles 25, shown with an asterisk in the drawing, are transported beyond drum 3 by the upper portion 17 of the airflow and are collected into a fourth collection zone D arranged behind the third collection zone C in the proximity of the rear wall 19 of the separation chamber 2. The collection zones A, B, C and D are separated from one another by means of partition plates 26, 27 and 28 arranged in the lower portion of the separation chamber 2. The partition plate 28 which divides the third collection zone C from the fourth collection zone D is prolonged upward, so that its upper end is arranged higher than the rotation axis of drum 3, and in addition it is inclined towards drum 3 in order to facilitate the separation between the lighter particles 25 and particles 24 having an intermediate weight and a non-flat shape.

The adjustment of the airflow by varying inclination and opening of nozzle 6, as well as the adjustment of the depression value inside the suction chamber 15 and of its opening angle β, allow to separate different materials comprising numerous types of particles. The opening area of nozzle 6 may be varied by means of an air lock 29 (shown in the drawing by broken lines) that can rotate around a substantially horizontal axis inside nozzle 6.

Further variations and/or additions may be made by those skilled in the art to the hereinabove described and illustrated embodiment of the invention, while remaining within the scope of the following claims.

Claims

1. A ballistic separator (1) comprising a separation chamber (2) in which particles of material (22, 23, 24, 25) can be thrown towards a rotating drum (3) by a gas flow, characterized in that the drum (3) is provided with a perforated shell (11) and is connected to at least one suction duct (10) suitable for generating a depression inside the drum (3).

2. A ballistic separator (1) according to the previous claim, characterized in that the drum (3) is coaxially assembled onto the suction duct (10) in a rotating manner.

3. A ballistic separator (1) according to one of the previous claims, characterized in that the suction duct (10) is provided with a suction opening (14) surrounded by walls (15a, 15b) defining a suction chamber (15) inside the drum (3).

4. A ballistic separator (1) according to the previous claim, characterized in that the suction chamber (15) can rotate around a horizontal axis inside the drum (3).

5. A ballistic separator (1) according to claim 3 or 4, characterized in that the suction chamber (15) contains one or more radial panels (16) hinged above the suction opening (14), which divide the volume of the suction chamber (15) into several sectors in order to adjust the direction and/or the flow-rate of the gas flow towards the suction opening (14).

6. A ballistic separator (1) according to the previous claim, characterized in that the radial panels (16) are three.

7. A ballistic separator (1) according to claim 5 or 6, characterized in that the radial panels (16) can be rotated around horizontal axes independently from one another.

8. A ballistic separator (1) according to one of claims 5 to 7, characterized in that the radial panels (16) include bulkheads (16a) suitable for reducing or preventing the flow of gas by rotating said panels (16).

9. A ballistic separator (1) according to one of claims 3 to 8, characterized in that the opening angle (β) of the suction chamber (15) in correspondence to the shell (11) of the drum (3) is comprised between 20° and 110°.

10. A ballistic separator (1) according to the one of the previous claims, characterized in that the depression generated by the suction duct (10) inside the drum (3) is comprised between 490 and 2940 Pa.

11. A ballistic separator (1) according to one of the previous claims, characterized in that the depression in correspondence of the shell (11) of the drum (3) is comprised between 390 and 1470 Pa.

12. A ballistic separator (1) according to one of the previous claims, characterized in that the flow of gas inside the separation chamber (2) is generated by at least one nozzle (6).

13. A ballistic separator (1) according to the previous claim, characterized in that the thrust pressure of the gas flow coming out from the nozzle (6) is comprised between 150 and 1960 Pa.

14. A ballistic separator (1) according to claim 12 or 13, characterized in that the inclination of the nozzle (6) with respect to a horizontal plane can be varied at a deviation angle (γ) being larger than 30°.

15. A ballistic separator (1) according to one of claims 12 to 14, characterized in that the area of the opening of the nozzle (6) can be varied by means of a bulkhead (29) rotatable around a substantially horizontal axis inside the nozzle (6).

16. A ballistic separator (1) according to one of the previous claims, characterized in that the upper wall (18) of the separation chamber (2) is inclined towards the rear and lower portion of this chamber (2).

17. A ballistic separator (1) according to one of the previous claims, characterized in that the separation chamber (2) includes collection zones (A₅ B, C, D) of the particles of the material to be separated, which are divided from one another by means of partition plates (26, 27, 28) arranged in the lower portion of the separation chamber (2).

18. A ballistic separator (1) according to the previous claim, characterized in that a first collection zone (A) is arranged under the front portion of the drum (3).

19. A ballistic separator (1) according to claim 17 or 18, characterized in that a second collection zone (B) is arranged under the rear portion of the drum (3).

20. A ballistic separator (1) according to the previous claim, characterized in that a third collection zone (C) is arranged behind the second collection zone (B).

21. A ballistic separator (1) according to the previous claim, characterized in that a fourth collection zone (D) is arranged behind the third collection zone (B).

22. A ballistic separator (1) according to the previous claim, characterized in that the partition plate (28) dividing the third collection zone (C) from the fourth collection zone (D) is prolonged upward, so that its upper end is arranged higher than the rotation axis of the drum (3).

23. A ballistic separator (1) according to claim 21 or 22, characterized in that the partition plate (28) dividing the third collection zone (C) from the fourth collection zone (D) is inclined towards the drum (3). 24. A method to separate particles of material (22, 23, 24, 25), comprising the subsequent operation steps:

- introducing such particles (22, 23, 24, 25) into a separation chamber (2) of a ballistic separator (1);

- throwing such particles (22, 23,

24, 25) towards a rotating drum (3) inside the separation chamber (2) by means of a gas flow; characterized in that a depression is generated inside the drum (3), which is provided with a perforated shell (11).

25. A method according to the previous claim, characterized in that the depression inside the drum (3) is comprised between 490 and 2940 Pa.

26. A method according to claim 24 or 25, characterized in that the depression in correspondence to the shell (11) of the drum (3) is comprised between 390 and 1470 Pa.

27. A method according to one of claims 24 to 26, characterized in that the thrust pressure of the flow of gas being introduced into the separation chamber (2) is comprised between 150 and 1960 Pa.

28. A method according to one of claims 24 to 27, characterized in that the ballistic separator (1) is a ballistic separator according to one of the claims 1 to 23.