EP1069217A1 - Apparatus for detecting polluting matter in the fibre materials such as cotton or other - Google Patents

Abstract

The appts. (2) to detect the presence of impurities in fiber materials, such as cotton and the like, is located between the bale breakers and the downstream fiber processing stations where it passes in front of an impurity ejection opening (3). The detection system is a combination of an optical detector (4) and an ultrasonic detector (5) across the material flow and upstream of the separator (6) which removes detected matter. The sorting machine is pneumatic with an air carrier channel (1) where the fiber material is transported by a flow of compressed air. The material is a mixture of air or fibers or a web, to move in front of the detector (2), and the impurities are ejected through an opening (3) in the channel (1). The fiber material can also be in the form of a web which is moved mechanically, such as by a feed drum or a conveyor belt. The fiber material can also be allowed to drop by gravity through a shaft, to build up at the bottom to be taken off for scanning. The feed drum or conveyor belt are of materials which absorb ultrasonic waves, and generate a command to separate and remove detected impurities. The detected matter is ejected by air jets under the perforated drum or belt, and be carried in the air streams to a facing collection system. The accumulated fibers at the base of a drop shaft build up in a supply bin or the like, to be moved passed the detector (2) and impurities are ejected through a channel opening (3). The optical detection system (4) has an array of lights to deliver light beams at the fiber flow in the channel (1) or at the mechanical feeds, to be registered by opposing light receivers which determine changes in contrast which occur through the reflection of light by impurities within the fibers. The ultrasonic detection system (5) has at least one assembly composed of a transmitter (5'), absorber (5) and receiver (5'), deployed at the fiber feed path. The transmitter delivers ultrasonic waves in a wavelength of ≤ 1 cm and at frequencies of 50-200 kHz. The ultrasonic transmitter has a long and thin shape, and the receiver (5') has a large number of small cells forming a surface area matching the shape and dimensions of the transmitter (5'). The bandwidth of each receiver cell is at least 4 kHz, forming the receiver (5'). The ultrasonic transmitter (5') has a width equal to that of the pneumatic carrier channel (1) or the mechanical fiber transport system. The individual receiver cells each have a reception surface area of max. 1 cm<2>, next to each other without gaps, to form the receiver (5') across the width of the pneumatic carrier channel (1) or the mechanical transport system. The ejection system (6), for the detected impurities, is an assembly of jets across the width of the pneumatic carrier channel (1) or the mechanical transport, facing the ejection opening (3). The jets are operated by command signals derived from the detection of impurities at the optical detection system (4) or the ultrasonic receiver cells (5').

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 into 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 beam optics.

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 plastics 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, towards 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 annexed drawing, which represents in a partial view and in section the pollutant detection system.

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 free accumulation means, 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 ultrasound absorbing 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 or a tablecloth, and passes in front of the device 2 for detecting materials 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 gravity transport channel. while the individual cells forming the 5 "receiver have a receiving surface of about 1 cm ² at most and are arranged side by side without gap, also over the entire width of the transport channel pneumatic 1, of the vertical gravity transport channel or of the mechanical transport device. The depth of the vertical gravity transport channel corresponds, in fact, to the dimension of the channel perpendicular to the direction of the material flow, therefore to the width of the pneumatic conveying channel 1. For example, the height of the pneumatic conveying channel 1 or of the mechanically transported ply or the width of the vertical gravity conveying channel can advantageously be 80 mm. As a result, the receiver 5 "'is able to recognize a pollutant in about 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 free or of the 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 movement 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 of 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 detection means 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 pollutions of very low importance and thus also eliminate these.

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)

Device for detecting pollutants in fibrous materials such as cotton or others, fitted to a sorting machine interposed between a processing machine and processing machines in downstream, in which the material to be sorted is moved in front of a device (2) for detection of pollutants, which are ejected through an opening (3) of the machine, characterized in that it is essentially constituted by the combination of means (4) for optical detection and means (5) for ultrasonic detection arranged transversely to a material flow transported from a working machine, upstream of a means (6) of pollutants, to processing machines in downstream. Device according to claim 1, characterized in that the sorting machine is pneumatic and has a transport channel pneumatic (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 device (2) for detecting pollutants, which are ejected through an opening (3) of said channel (1). Device according to claim 1, characterized in that the sorting machine is of the type in which the scrolling of material is carried out by using a mechanical transport device for the sheet of material, in which the material is conveyed in a sheet on a mechanical means, such as a spreading drum or a conveyor belt. Device according to claim 1, characterized in that the sorting machine is of the type in which the scrolling of material in the form free air or groundwater mixing is carried out by gravity in a vertical transport, at the exit of a means of accumulation of fibers, such than a hopper or the like. Device according to any one of claims 1 and 3, characterized in that the detection means, constituted by the combination of means (4) for optical detection and means (5) for ultrasonic detection, are placed transversely to the material flow, cooperate with the spreading drum or the conveyor belt, which are made of an ultrasonic absorbent material, and issue an order removal of impurities by pneumatic means in the form of nozzles arranged under the carpet or in the drum, which are perforated and allow the passage of polluting material propulsion air to a corresponding reception device located opposite these nozzles. Device according to any one of claims 1 and 4, characterized in that the gravity transport of the free air mixture or the web at the outlet of a fiber accumulation means, such as a hopper or the like, 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 a device 2 for detecting pollutants, which are ejected through an opening 3 of said channel. Device according to any one of Claims 1 to 5, characterized in that the optical detection means (4) consist of light bars emitting a light beam towards the flow of materials crossing the channel (1), or transported mechanically or transported by gravity in a vertical channel, and cooperating with cells receptors analyzing the contrasts appearing during the passage of light rays passing through the material transported or reflected by the pollution. Device according to any one of Claims 1 to 5, characterized in that the ultrasonic detection means (5) consist of at least one transmitter (5 ') - absorber (5 ") - receiver (5"') assembly ultrasound arranged on either side of the pneumatic transport channel (1), of the vertical gravity transport channel, or parallel to the mechanical transport of the material web, transverse to the flow of the latter and in front of this transport device with respect to said flow matter. Device according to claim 8, characterized in that the transmitter (5 ') emits waves less than 1 cm long and works to frequencies between 50 kHz and 200 kHz. Device according to claim 8, characterized in that the transmitter (5 ') of the ultrasonic detection means (5) is in the form an elongated element of small thickness and the receiver (5 "') consists by a large number of small individual cells and its total width substantially equivalent to that of the elongated element forming the transmitter (5 '). Device according to any one of claims 8 and 10, characterized in that the bandwidth of each individual cell forming the receiver (5 "') is at least 4 kHz. Device according to either of Claims 8 and 10, characterized in that the transmitter (5 ') 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 channel of gravity transport, while the individual cells forming the receptor (5 "') have a receiving surface of about 1 cm ² at most and are arranged side by side without gap, also on the entire width of the pneumatic transport channel (1), the vertical gravity transport channel or the mechanical transport device. Device according to claim 1, characterized in that the extraction means (6) is in the form of a nozzle ramp 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 ultrasonic receptors (5 "').

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