EP3970868A1

EP3970868A1 - Machine and method for viewing a bulk powder product

Info

Publication number: EP3970868A1
Application number: EP21197085.0A
Authority: EP
Inventors: Marco TOSCHI; Matteo FILIPPI; Alessio GOVONI; Redis GJONAJ
Original assignee: Elica Asm Srl
Current assignee: Elica Asm Srl
Priority date: 2020-09-18
Filing date: 2021-09-16
Publication date: 2022-03-23
Anticipated expiration: 2041-09-16
Also published as: IT202000022012A1; EP3970868B1

Abstract

The machine (1) comprises a dispensing head (3) of the bulk powder product and a viewing system (6) of the bulk powder product dispensed by the dispensing head (3). The dispensing head (3) comprises a first hopper (21) with a first outlet (25), and a second hopper (23) with a second outlet (27), The second hopper (23) is positioned below the first hopper (21). The first hopper and the second hopper are associated with a vibrating device (40).

Description

TECHNICAL FIELD

The present invention relates to the field of machines for quality control. More specifically, the present invention concerns improvements to machines for viewing bulk powder products, for example for checking for the presence of defects.

BACKGROUND ART

In many fields, in particular in the food sector, bulk powder products are produced and packaged. In the food sector, for example, it is known to produce powdered food substances, which are then used by the final consumer to prepare beverages by adding water. By way of non-limiting example, powdered milk, in particular powdered milk for infants, is produced.
These products must be subjected to strict quality controls during production and packaging.
Currently there are no machines capable of efficiently carrying out a visual control for products of this type.

SUMMARY

To allow efficient and automatic viewing, i.e. visual control, of a bulk powder product through a viewing system, which can comprise one or more video cameras, for example for the purpose of detecting defects, there is provided a machine comprising: a dispensing head of the bulk powder product and a viewing system of the bulk powder product dispensed by the dispensing head. The dispensing head comprises a first hopper with a first outlet, and a second hopper with a second outlet. The second hopper is positioned below the first hopper. Advantageously, the first hopper and the second hopper are associated with a vibrating device.
With this configuration, the bulk powder product is loaded into the first hopper and dispensed by the first hopper to the second hopper. Through the vibration movement imparted to the second hopper, the bulk product exits from the outlet of the second hopper forming a curtain of bulk product falling freely toward a path below, in which viewing members, such as one or more video cameras and respective lighting systems can be arranged.
In some embodiments, the outlet of the second hopper has an elongated shape, so that the bulk product exiting by gravity from the second hopper forms a curtain of limited depth, preferably a depth (i.e., thickness) which is much smaller than the width of the curtain. Advantageously, the elongated slot shape of the second outlet forms a curtain of product that has a sufficiently limited depth to allow improved viewing of the bulk powder product.
The first hopper can also be subjected to vibration, to facilitate transfer of the bulk product from the first hopper to the second hopper.
The superimposed arrangement of the two hoppers causes the bulk powder product to be fed to the second hopper gradually, avoiding compaction of the powder close to the outlet of the second hopper. This facilitates the formation of a uniform curtain of bulk product falling freely from the second hopper.
For some types of bulk powder product, which can tend to form lumps or clumps, it may be useful to arrange a member adapted to break up lumps of the bulk powder product in the second hopper. This member can comprise a screen, which can be arranged in the outlet of the second hopper.
The outlet of the second hopper can be slot shaped, with a ratio between length and width for example ranging from 1 to 100,000, preferably from 10 to 100,000, more preferably from 10 to 500, even more preferably from 10 to 100, for example from 15 to 70.
The vibrating device associated with the hoppers can be configured to cause only the second hopper to vibrate. However, for more efficient operation, the vibrating device is configured to cause both the hoppers to vibrate. This facilitates the advance of the bulk product in the first hopper, or upper hopper, and in the second hopper, or lower hopper.
To obtain a simple and compact machine, it is advantageous for the upper hopper and the lower hopper to be rigidly connected to each other and/or to a common member, to transmit the same vibration to both the hoppers through a single actuator, i.e., a single vibrating member.
In currently less preferred embodiments, the first hopper and the second hopper can be combined with a first vibrating member and a second vibrating member, which in combination form the vibrating device. This configuration is more complex, but may allow a higher degree of flexibility, inasmuch it permits to vibrate the first hopper and the second hopper in different modes, for instance with different frequencies or amplitudes.
The vibrating device can be configured to generate a vibration movement in a direction substantially parallel to the longitudinal extension of the outlet of the second hopper. A movement of this type facilitates regular delivery of the bulk product from the second hopper. If two separate vibrating members are provided, they may be arranged such that both the first hopper and the second hopper perform a vibration movement in the same direction.
According to a further aspect, a method for viewing a flow of a bulk powder product is described, comprising the steps of:

accumulating the bulk powder product in a first hopper;
gradually transferring the bulk powder product from the first hopper to a second hopper, positioned under the first hopper and provided with a, preferably elongated outlet;
vibrating the first hopper and the second hopper;
dispensing a falling curtain of bulk powder product from the second hopper toward a path in front of a viewing member.

Further advantageous optional features and embodiments of the machine and of the method of the present invention will be described below with reference to the accompanying drawings and are defined in the appended claims, which form an integral part of the description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by following the description and the accompanying drawings, which illustrate a non-limiting exemplary embodiment of the invention. More in particular, in the drawing:

Fig. 1 shows a schematic overall view of an embodiment of a machine according to the present invention;
Fig. 2 shows an axonometric view of the dispensing head;
Fig. 3 shows a lateral view of the dispensing head;
Fig. 4 shows a front view according to IV-IV of Fig. 3 of the dispensing head; and
Figs. 5 and 6 show sections according to the lines V-V and VI-VI of Figs. 4 and 3, respectively, where in Fig.5 the actuator has been omitted.

DETAILED DESCRIPTION

In the present description, the terms "vertical", "upper", "lower", "above", "below" and equivalents refer to the position of the respective members when the machine is in the operating position.
An overall and simplified view of an embodiment of the machine is illustrated in Fig. 1. The machine is indicated as a whole with 1. It comprises a load-bearing structure 2, on which a dispensing head 3 is mounted. A path along which the bulk product falls freely by gravity extends below the dispensing head. The path is indicated schematically with 5.
A viewing system, indicated as a whole with 6, is associated with the path 5, to acquire images of the bulk product falling freely along the path 5. In some embodiments, the viewing means can comprise one or more video cameras with suitable lighting systems. In the embodiment shown, the machine 1 comprises a first video camera 7 and a second video camera 9 placed on opposite sides of a vertical falling plane of the bulk product. A lighting system is associated with the first video camera 7. In the embodiment illustrated, the lighting system associated with the video camera 7 comprises a first upper light source 11 and a second lower light source 13. The two light sources are oriented so as to light the area in which the focus of the video camera 7 is located. This focus is on the vertical falling plane of the bulk product fed by the dispensing head 3, along the falling path 5.
In the embodiment shown, a backlight source 15, which defines a background for better framing of the images of the falling product, is associated with the first video camera 7. The backlight source 15 is on the opposite side of the falling path 5 with respect to the video camera 7.
In the embodiment shown, the second video camera 9 is associated with a lighting system symmetrical to the one associated with the first video camera 7. The second lighting system comprises a third upper light source 17 and a fourth lower light source 19, which direct light beams converging in the focus of the video camera 9, onto the falling plane of the bulk product along the path 5. A backlight source 21 is placed in front of the video camera 9, on the opposite side of the falling plane with respect to the video camera 9.
The video cameras and the lighting systems can be interfaced with an image control and processing unit, not shown.
An embodiment of the dispensing head 3 is shown in detail in Figs. 2 to 6.
The dispensing head 3 comprises a first hopper, or upper hopper 21 and a second hopper, or lower hopper 23. As can be seen in particular in the sections of Figs. 5 and 6, the upper hopper 21 terminates at the bottom with a first outlet 25 which is located inside the lower hopper 23, i.e., at a lower height with respect to the upper edge 23A of the lower hopper 23.
In the embodiment shown, the outlet 25 of the first hopper 21 has a circular shape, but in other exemplary embodiments the shape of the outlet 25 of the first hopper 21 may differ, for example elliptical or polygonal.
In the embodiment shown, the first hopper 21 has a substantially conical shape, but in other embodiments the first hopper 21 could have different shapes, for example pyramidal.
The second hopper 23, or lower hopper, has an outlet 27, preferably of elongated shape. In the embodiment shown the outlet 27 of the second hopper 23 has the shape of a slot elongated in a direction D. The slot forming the outlet 27 of the second hopper 23 can, for example, have a ratio between length (dimension in direction D) and width (dimension in direction orthogonal to D) ranging from 15 to 70. The value indicated must be intended as an example and currently preferred, but not limiting, and can depend on the nature of the bulk product to be processed.
A member adapted to break up lumps of the bulk powder product contained in the second hopper 23 is associated with the outlet 27 of the second hopper 23. In the embodiment shown, this member comprises a screen 28 positioned in the outlet 27 of the second hopper 23. This embodiment is particularly simple and efficient, but it would also be possible to proovide members of a different shape having similar functions, such as a series of linear elements or bars arranged according to variable orientations inside the second hopper 23.
The two hoppers 21, 23 are integral with a plate 31 that is connected to a frame 33 fixed, by means of beams 35, to the load-bearing structure 2 of the machine 1. Elastic blocks 37 are interposed between the plate 31 and the frame 33 to allow the plate 31 to oscillate, i.e., vibrate, with respect to the frame 33. In some embodiments the elastic blocks 37 can consist of or comprise silent blocks.
An actuator 39, which can impart an oscillatory movement to the plate 31 with respect to the frame, is positioned between the plate 31 and the frame 33. The actuator 39 forms, together with the plate 31, a vibrating device 40 that causes the two hoppers 21, 23 to vibrate simultaneously. In the embodiment shown, the vibration is in the direction D of longitudinal extension of the outlet 27 of the second hopper 23.
In the embodiment shown, a single vibrating device that causes both the hoppers 21, 23 to vibrate is provided. However, it would also be possible to use two separate vibrating devices, i.e. two vibrating actuators forming the vibrating device, one for the upper hopper 21 and one for the lower hopper 23.
The machine described above operates as follows. The bulk product to be viewed is fed with known means, such as an auger or conveyor belt (not shown) to the first hopper 21. From here the bulk product is fed by gravity through the outlet 25 of the first hopper 21 into the second hopper 23. The vibration imparted to the first hopper 21 prevents bridging of the bulk product and makes advance of the bulk product safer and more uniform.
The bulk product accumulates in the second hopper 23 until reaching the level of the outlet 25 of the first hopper 21. The vibration movement of the second hopper 23 facilitates dispensing of the bulk product by falling by gravity through the outlet 27 of the second hopper 23. The screen 28 facilitates break up of any lumps of bulk product that can form upstream of the outlet 28, along the feed path of the bulk product.
Distribution of the bulk product in the first hopper, or upper hopper, 21 and from this into the second hopper, or lower hopper 23, prevents compaction of the bulk product in the area above the outlet 27 from which it is dispensed by gravity along the path 5.
The shape of the outlet 27 of the second hopper 23 is such as to generate a curtain of bulk product falling freely along the path 5, of sufficiently small depth to allow efficient viewing. The arrangement of the double hopper and of the screen 28, or other equivalent member, makes flow uniform and free from lumps, even in the case of bulk products that have the tendency to form clusters, for example as a result of humidity.

Claims

A machine (1) for viewing a bulk powder product, comprising in combination:
- a dispensing head (3) for dispensing the bulk powder product;

- a viewing system (6) for viewing the bulk powder product dispensed by the dispensing head (3),
wherein: the dispensing head (3) comprises a first hopper (21) with a first outlet (25), and a second hopper (23) with a second outlet (27), the second hopper (23) being positioned below the first hopper (21); the first hopper and the second hopper are associated with a vibrating device (40).
The machine (1) of claim 1, wherein the outlet (27) of the second hopper (23) has an elongated shape.
The machine (1) of claim 1 or 2, wherein a member adapted to break up lumps of the bulk powder product is associated with second hopper (23).
The machine (1) of claim 3, wherein the member adapted to break up lumps of the bulk powder product comprises a screen (28).
The machine (1) of claim 4 wherein the screen (28) is positioned in the outlet (27) of the second hopper (23).
The machine (1) of one or more of the preceding claims, wherein the outlet (27) of the second hopper (23) is slot shaped, with a ratio between length and width preferably ranging from 1 to 100,000, preferably from 10 to 100,000, more preferably from 10 to 500, even more preferably from 10 to 100 and even more preferably from 15 to 70.
The machine (1) of one or more of the preceding claims, wherein the outlet (25) of the first hopper (21) is substantially circular.
The machine (1) of one or more of the preceding claims, wherein the outlet (25) of the first hopper (21) is positioned inside the second hopper.
The machine (1) of one or more of the preceding claims, wherein the vibrating device (40) generates a vibration movement in a direction substantially parallel to the longitudinal extension of the outlet (27) of the second hopper (23).
The machine (1) of one or more of the preceding claims, wherein the first hopper (21) and the second hopper (23) are rigidly connected to a vibrating element, typically a vibrating plate (31), connected to an actuator (39) that causes the first hopper (21) and the second hopper (23) to vibrate.
The machine (1) of one or more of the preceding claims, comprising at least a first video camera (7) positioned on one side of a vertical plane aligned with the outlet (27) of the second hopper (23) and parallel to the longitudinal extension of the outlet (27) of the second hopper (23).
The machine (1) of claim 11, comprising at least a second video camera (9) positioned on a second side of the vertical plane aligned with the outlet (27) of the second hopper (23) and parallel to the longitudinal extension thereof.
The machine (1) of claim 11 or 12, wherein each video camera is associated with a lighting system (11 - 20).
The machine (1) of claim 13, wherein the lighting system comprises, for each video camera (7, 9), two light sources (11, 13; 17, 19) positioned above and below the respective video camera and oriented so as to direct respective light beams toward the area framed by the video camera.
The machine (1) of one or more of claims 11 to 14, wherein a respective backlight source (15, 20) is associated with at least one video camera (7, 9), and preferably with each video camera.
A method for viewing a flow of a bulk powder product, comprising the steps of:
- accumulating the bulk powder product in a first hopper (21) provided with a first outlet (25);

- gradually transferring the bulk powder product from the first hopper (21) to a second hopper (23), positioned under the first hopper and provided with a second outlet (27);

- vibrating the first hopper (21) and the second hopper (23);

- dispensing a falling curtain of bulk powder product from the second hopper toward a path (5) through a viewing system (6).
The method of claim 16, wherein the second outlet (27) has an elongated shape, and wherein the bulk powder product is dispensed by falling from the second hopper (23) forming a curtain having a width greater than the depth.
The method of claim 16 or 17, comprising the step of crumbling the bulk powder product before dispensing the bulk powder product through the second outlet (27), preferably causing the bulk powder product to pass through a screen (28), preferably positioned in the second outlet (27).