EP1069217B1 - Sorting machine for fibre materials such as cotton comprising a device for detecting polluting matter - Google Patents

Description

The present invention relates to the field of the textile industry, in particular the treatment of the raw material after working and in particular sorting and elimination of pollutants in fibrous materials such as cotton or others, and relates to a device for detecting polluting materials.

Currently, the detection of pollutants contained in raw textile fibers and especially in cotton or other fibrous materials, namely animal, plant or other waste, having possibly used for baling the raw material, are generally detected after working, using a sorting machine, in which the material is propelled in an air flow forming a mixture air fibers or a relatively thin web. In such machine, pollutants are detected by means of devices electromagnetic or electron radiation optics (see for example DE29719245U).

There are also mechanical transport devices of a sheet of material, in which the material is conveyed in sheet on mechanical means, such as drums or conveyor belts, and detection means are placed transversely to the material flow and issue an impurity removal command to means tires in the form of nozzles arranged under the carpet or in the drum. To this end, the drum and the carpet are advantageously perforated and allow the passage of polluting material propulsion air to a corresponding receiving device.

In addition, it is also known to carry out a verification of surface of bale fibrous material, before working, by means of surface detectors.

However, these known detection devices are only adapted to a very specific detection mode and do not allow elimination of all pollutants. Indeed, in the case of cotton, in particular, it is necessary to be able to remove both already used cotton parts such as colored rag particles, than other pollutants, especially synthetic materials or metallic materials.

However, to date, there is no mechanism to ensure simultaneously eliminating pollutants made of the same material first that the product to be depolluted, and pollutants in a material different.

The object of the present invention is to overcome these drawbacks by proposing a device for detecting pollutants in fibrous materials such as cotton or other, which allows to check simultaneously existence and elimination, in a flow of displaced matter pneumatically, mechanically or by gravity, of all products pollutants contained in said material.

To this end, the invention relates to a device characterized in what it basically consists of is the combination of means of optical detection and ultrasonic detection means arranged transversely to a flow of material transported from a machine of working, upstream of a means of extraction of pollutants, to downstream processing machines.

The invention will be better understood, thanks to the description below, which relates to a preferred embodiment, given as non-limiting example, and explained with reference to the single figure of schematic appended drawing, which represents in a partial view and in section the pollutant detection device.

The single figure in the accompanying drawing partially represents a sorting machine interposed between a processing machine and downstream processing, in which the material to be sorted is moved in front of a device 2 for detecting pollutants, which are ejected through an opening 3 of the machine.

According to the invention, the device 2 for detecting pollutants is essentially constituted by the combination of optical detection means 4 and ultrasonic detection means 5 arranged transversely to a flow of material transported from a working machine, upstream of a means 6 for extracting the materials polluting, to downstream processing machines.

In the embodiment shown in the accompanying drawing, the sorting machine is pneumatic and has a transport channel tire 1, in which the material to be sorted is propelled by through a pressurized air flow, forming an air mixture fibers or a sheet, and passes in front of the material detection device 2 pollutants, which are ejected through an opening 3 of said channel 1.

However, the invention is also applicable to machines sorting machines, not shown, in which the material is scrolled by using a mechanical transport device for a sheet of material, in which the material is conveyed in a web on a means mechanical, such as a spreader drum or conveyor belt, or still in which the air fibers mixture or the sheet is transported by gravity at the exit of a means of accumulation of fibers, such as a hopper or the like.

When using a mechanical transport device, the detection means, constituted by the combination of means of optical detection and ultrasonic detection means, are placed transversely to the material flow, cooperate with the spreading drum or the conveyor belt, which are then preferably made in one ultrasonic absorbent material, and issue an elimination command impurities in pneumatic means in the form of nozzles arranged under the carpet or in the drum, which are advantageously perforated and allow the passage of polluting material propulsion air to a corresponding reception device located opposite these nozzles.

In the case of implementation of a device involving a gravity transport of the air fibers mixture or of the sheet at the outlet of a fiber accumulation means, such as a hopper or the like, said transport is carried out through a vertical transport channel, in which the material to be sorted falls under its own weight, forming an air mixture fibers or a sheet, and passes in front of the material detection device 2 pollutants, which are ejected through an opening 3 of said channel.

The optical detection means 4 are advantageously constituted by light bars emitting a light beam in direction of material flow through channel 1, or transported mechanically or transported by gravity in a vertical channel, and cooperating with receptor cells analyzing the contrasts appearing during the passage of light rays passing through matter transported or reflected by pollution. Any appearance of contrast important means the existence in the material flow of a product or a original material or constitution or different colors in front be eliminated by means of the extraction means 6 through the opening 3 of the channel 1.

The ultrasonic detection means 5 consist of at least a 5 'transmitter - 5 "absorber - 5" receiver of ultrasound arranged on either side of the pneumatic conveying channel 1, of the vertical channel of gravity transport, or parallel to the mechanical transport device of the sheet of material, transversely to the flow of the latter and opposite of this transport device with respect to said material flow.

Thus, the 5 'transmitter continuously emits ultrasound in the direction of the absorber 5 "and the receiver 5" 'collects the ultrasound possibly reflected by pollutants passing through the beam emitted by the 5 'transmitter. Preferably, the 5 ′ transmitter emits waves of a length less than 1 cm and works at frequencies between 50 kHz and 200 kHz.

In the case of cotton, as the latter presents practically zero reflection characteristics, i.e. it achieves absorption of emitted ultrasound, all pollutants contained in the transported stream, such as plastic debris or others, have a strong reflection, even if they are small and cause the emission of a corresponding means control signal 6 by the 5 '' receiver.

According to a characteristic of the invention, the transmitter 5 'of the means 5 ultrasonic detection is advantageously in the form of a elongated element of small thickness and the 5 "receiver is constituted by a large number of small individual cells and its width total substantially equivalent to that of the elongated element forming the transmitter 5 '. Preferably, the bandwidth of each individual cell forming the 5 "receiver is at least 4 kHz.

The transmitter 5 'advantageously has a width equivalent to that of the pneumatic transport channel 1, or of the mechanical transport device or to the depth of the vertical transport channel by gravity, while the individual cells forming the receiver 5 "' have a receiving area of around 1 cm ² maximum and are arranged side by side without gaps, also over the entire width of the pneumatic transport channel 1, the vertical gravity transport channel or the device mechanical transport. The depth of the vertical gravity transport channel corresponds, in fact, to the dimension of the channel perpendicular to the direction of the flow of material, therefore to the width of the pneumatic transport channel 1. For example, the height of the pneumatic transport channel 1 or of the mechanically transported ply or the width of the vertical gravity transport channel can advantageously be 80 mm. it follows that the 5 "receiver is capable of recognizing a pollutant in a period of approximately 0.5 ms.

Light bars illuminate the material passing through the flow of pneumatically propelled material or flowing by gravity, or passing on the spreading drum or the conveyor belt and simultaneously the ultrasonic transmitter emits waves towards said flow through the pneumatic transport channel 1 or the gravity transport channel, spreader drum or conveyor belt, so that all products pollutants passing through light and wave fields cause corresponding reflections towards the optical receivers and 5 "ultrasound and thus allow delivery by the control means computer extraction signals corresponding to means 6.

This extraction is controlled by means computer control not shown and not described in detail, which takes into account counts, on the one hand, the characteristics of the product to be treated, namely, by example, cotton and, on the other hand, the running speed of the air mixture fibers or web of product in the pneumatic conveying channel 1, or in the vertical gravity transport channel or on the mechanical transport of the sheet of material to trigger in good time means 6, that is to say at a time interval consecutive to the detection corresponding to the displacement made by the pollutant detected so that it found in the area of action of the extraction means 6.

The extraction means 6 is in the form of a ramp of nozzles extending over the entire width of the pneumatic conveying channel 1, vertical gravity transport channel or transport device mechanical, opposite the pollutant elimination opening 3, these nozzles can be operated individually by the control means IT, according to the signals emitted by the optical detectors of the means 4 or by the individual cells of the 5 "ultrasonic receivers. as a result a transverse jet of compressed air can be delivered exactly to the location of the transported material flow, corresponding to the position of the pollutant previously detected by one of the aforementioned detectors.

Thanks to the invention, it is possible to verify the existence possible all types of pollution in fibrous materials in scroll through a sorting machine and perform disposal.

Indeed, the invention allows, on the one hand, to sort by taking into account existing contrasts, due to the very existence of different materials, both in colors and in their characteristics of own reflection and, on the other hand, to take into account transparent matters optical sorting, that is to say which cannot be detected by using optical means. In the latter case, the pollutants present in the flow of moving material, for example cotton, could not date, be eliminated.

The combination of detection means implemented by the present invention makes it possible to discern, in a material flow, materials which were to date transparent to known means of detection and which, therefore, could not be eliminated.

It follows that the invention makes it possible to obtain a material raw perfectly free of all pollutants. Because of the use of very small individual cells for the 5 "ultrasonic receiver. The invention makes it possible, in fact, to detect pollution of very small importance and thus also eliminate the latter.

Of course, the invention is not limited to the mode of realization described and represented in the appended drawing. Changes remain possible, especially from the point of view of the constitution of the various elements or by substituting technical equivalents, without however leaving the protection field of the invention.

Claims (13)

1. Sorting machine located between an opening machine and downstream processing machines provided with a device for detecting impurities in fibrous materials such as cotton or the like and in which the material to be sorted is moved in front of said device (2) for detecting impurities which are ejected through an aperture (3) of the machine, characterised in that the detection device (2) substantially consists of the combination of optical detection means (4) and ultrasonic detection means (5) disposed transverse to a material flow conveyed from an opening machine upstream from a means (6) for extracting impurities toward downstream processing machines, said optical detection means (4) comprising receiver cells which analyse the contrasts appearing during the passage of light beams through the conveyed material or reflected by the impurities, and said ultrasonic detection means (5) comprising a receiver (5''') which receives the ultrasonic waves possibly reflected by the impurities.
2. Machine according to claim 1, characterised in that the sorting machine is pneumatic and comprises a pneumatic conveying duct (1), in which the material to be sorted is propelled by a flow of compressed air, forming a mixture of air and fibres or a web, and passes in front of the device (2) for detecting impurities which are ejected through an aperture (3) of said duct (1).
3. Machine according to claim 1, characterised in that the sorting machine is of the type in which the flow of material is produced by using a mechanical conveying device for the material web, in which the material is conveyed in a web on a mechanical means, such as a feed drum or a conveyor belt.
4. Machine according to claim 1, characterised in that the sorting machine is of the type in which the flow of material in the form of a mixture of air and fibres or a web is produced by gravity in a vertical conveying duct at the exit of a fibre collecting means, such as a hopper or the like.
5. Machine according to either one of claims 1 or 3, characterised in that the detection means, consisting of the combination of optical detection means (4) and ultrasonic detection means (5), are located transverse to the flow of material, cooperate with the feed drum or conveyor belt which are produced in a material which absorbs ultrasonic waves, and transmit a command to remove impurities to pneumatic means in the form of perforated nozzles disposed below the belt or in the drum to allow the passage of air for propelling impurities towards a corresponding receiving device facing these nozzles.
6. Machine according to either one of claims 1 or 4, characterised in that the mixture of air and fibres or the web at the exit of a fibre collecting means such as a hopper or the like, is conveyed by gravity through a vertical conveying duct, in which the material to be sorted falls under its own weight, forming a mixture of air and fibres or a web, and passes in front of a device (2) for detecting impurities which are ejected through an aperture (3) of the said duct.
7. Machine according to any one of claims 1 to 5, characterised in that the optical detection means (4) consist of an assembly of lights emitting a beam of light in the direction of the flow of materials passing through the duct (1), or conveyed mechanically or by gravity in a vertical duct, and cooperating with receiver cells which analyse the contrasts appearing during the passage of rays of light through the material conveyed or reflected by the impurities.
8. Machine according to any one of claims 1 to 5, characterised in that the ultrasonic detection means (5) consist of at least one assembly of transmitter (5') - absorber (5") - receiver (5''') of ultrasonic waves arranged on either side of the pneumatic conveying duct (1), of the vertical duct for conveying by gravity, or parallel to the mechanical conveying device for the web of material, transverse to the flow of this material and facing this conveying device with respect to the flow of material.
9. Machine according to claim 8, characterised in that the transmitter (5') transmits waves with a length of less than 1 cm and operates at frequencies between 50 kHz and 200 kHz.
10. Machine according to claim 8, characterised in that the transmitter (5') of the ultrasonic detection means (5) is in the form of an elongate thin element and the receiver (5"') consists of a large number of individual cells with small dimensions and its total width is substantially equivalent to that of the elongate element forming the transmitter (5').
11. Machine according to either one of claims 8 and 10, characterised in that the bandwidth of each individual cell forming the receiver (5"') is at least 4 kHz.
12. Machine according to either of claims 8 or 10, characterised in that the transmitter (5') has a width equivalent to that of the pneumatic conveying duct (1), or the mechanical conveying device or the depth of the vertical duct for conveying by gravity, while the individual cells forming the receiver (5"') have a receiving surface of a maximum of about 1 cm² and are disposed next to one another without a gap, similarly over the entire width of the pneumatic conveying duct (1), the vertical duct (4) conveying by means of gravity or the mechanical conveying device.
13. Machine according to claim 1, characterised in that the extraction means (6) is in the form of an assembly of nozzles extending over the entire width of the pneumatic conveying duct (1), the vertical duct conveying by gravity or the mechanical conveying device, facing the aperture (3) for removing impurities, these nozzles being individually actuable by the computer control means, as a function of the signals transmitted by the optical detectors of the means (4) or by the individual cells of the ultrasonic receivers (5"').

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