EP0098207A1 - Purifying device for products such as foodstuffs, and purifying installation including said device - Google Patents

Abstract

1. A device for purifying, through mechanical treatment, products capable of moving on a surface from their own weight, such as foodstuffs, e.g. peas or the like, or granular products, of the type including a drum (1) in the form of a cylindrical hollow tube rotatable about an axis (1a) inclines with respect to the horizontal, means for rotating the said drum (1), means for feeding the products into the said drum (1) at its upper end (1b), means for collecting the purified products at the lower end (1c) of the said drum, and means for detaching and collecting the elements adhering to the internal surface of the said drum, characterized in that the internal surface of the drum (1) in cross-section is multi-lobe (7), advantageously regular and with a concavity looking towards the interior of the drum.

Description

The present invention relates to a device for purifying, by mechanical treatment, of products containing elements which can be entrained by a surface by capillary adhesion on said surface.

A more particular subject of the invention is the purification by mechanical treatment of products which can move on a surface under the effect of their own weight, such as foodstuffs picked in bulk, for example peas, to separate them from the leaves. of plants, pods, herbs or other similar materials which can adhere, for example by capillarity on a surface, collected at the same time as the said foodstuffs, at the place of harvest. The invention also relates to an installation for the purification and cleaning of these foodstuffs.

Several devices and methods are already known for purifying products such as foodstuffs and in particular peas. These methods essentially consist in eliminating the light elements by feeding the crop in an ascending air stream, in collecting the peas not entrained by the air stream and in sieving them using sieves of different sizes of mesh and finally to wash them.

However, the cultivation on an industrial scale of these foodstuffs has notably led to the mechanization of harvesting crops. Therefore, where the old manual and mechanical mowing and picking techniques were necessary to collect the steps, a single specialized machine can now be used. However, this machine, as sophisticated as it is, can not perform a picking as "clean" as in the past. In addition, the shelling of peas has also been automated, which has increased the quantity of pods or pod waste contained in the peas to be treated. Therefore, the subsequent purification treatment of the mixture formed by all of these products is necessary to extract the consumable products from said mixture.

The known purification and separation methods described briefly above give good results if the percentage of elements to be eliminated contained in the crop is relatively low. Above a certain percentage, it is necessary to reduce the processing throughput of these devices in order to obtain, at the end of the installation, a "clean" consumable product. However, to maintain the quality of the product, it is often necessary to increase the air flow in the separation process in an ascending air stream, which causes the entrainment of part of the consumable foodstuffs and therefore decreases the overall performance of the treatment plant.

Particularly also known from the teaching of American patents No. 3,507,387 and No. 3,508,645 is a device for purification by mechanical treatment, products which can move on a surface under the effect of their own weight, such as foodstuffs, for example peas or the like, or granular products, of the type comprising a drum in the form of a cylindrical hollow tube, mounted to rotate around an axis inclined relative to the horizontal, means for rotating said drum, means for feeding products into said drum at its upper end, means for collecting the purified products at the lower end of said drum, and means for removing and collecting the elements adhering to the interior surface of said drum.

The present invention therefore relates to an improvement to this device allowing better purification of the products thanks to a more complete elimination, of the harvest, of the impurities.

To this end, the present invention relates to a device of the type described above, and characterized in that the interior surface of the drum has a multilobed cross section, advantageously curvilinear and regular.

The shape of the lobes allows better mixing of the products inside the drum and makes it possible to reduce their radial displacement in the drum, thus making it possible to improve the purification of the products.

According to another characteristic of the invention, the interior surface of the aforementioned cylinder is a surface with an icy appearance, preferably an icy metallic surface; which promotes the adhesion effect on the inclined surface.

According to yet another characteristic of the invention, the products to be purified and / or the interior surface of the aforementioned cylinder are moistened before the products are introduced into the aforementioned drum.

According to another characteristic of the invention, the aforementioned means for taking off and collecting the elements adhering to the interior surface of the aforementioned drum include a squeegee member, one edge of which is maintained in constant contact with the interior surface of the drum, along substantially a generatrix. thereof located downstream of the product feed zone with respect to the direction of rotation of the drum, and advantageously at the top of said drum, and a member such as a belt conveyor or a vibrating trough for collecting said said unstuck elements and evacuate them outside the drum.

According to yet another characteristic of the invention, the aforementioned squeegee member is provided on its edge in contact with the inner surface of the drum with a strip made of a material with elastic property such as, for example, rubber or a synthetic material.

According to another characteristic of the invention, the aforementioned member forming a squeegee is supported at each of its ends by an arm system mounted pivotally and actuated by at least one spring to maintain the aforementioned strip in constant contact with the internal surface of the drum. .

According to yet another characteristic of the invention, the device comprises deflectors defining a chute between the aforementioned squeegee member and the aforementioned conveyor member.

According to another characteristic of the invention, the aforementioned means for feeding products into the aforementioned drum comprise a feed hopper and an endless band in rotation, said band being disposed on the lower surface of the hopper, and being inclined relative to the horizontal, the strip having a direction of movement opposite to the direction of movement of the products thereon.

The invention also relates to an installation for purifying products such as, for example, foodstuffs or granular products, of the type comprising in particular and successively a device for purifying by gravity in an ascending current of air, an apparatus for sieving and an appliance for washing foodstuffs, characterized in that it comprises, at the start of the chain, a purification device 'in accordance with the invention for pre-cleaning the products before or after their passage through the purification device by gravity in an ascending draft.

• La figure 1 représente schématiquement une vue en élévation de l'appareil conforme à l'invention, avec arrachements partiels.
• La figure 2 est une vue suivant la flèche II de la figure 1 de l'extrémité supérieure du dispositif conforme à l'invention, avec arrachements partiels ; et
• La figure 3 est une vue en coupe selon la ligne III-III de la figure 1.

The invention will be better understood and other characteristics, details and advantages thereof will appear more clearly in the light of the following explanatory description of a device according to the invention, given solely by way of example and made with reference to the accompanying nonlimiting drawings in which:

• Figure 1 schematically shows an elevational view of the apparatus according to the invention, with partial cutaway.
• Figure 2 is a view along arrow II of Figure 1 of the upper end of the device according to the invention, with partial cutaway; and
• Figure 3 is a sectional view along line III-III of Figure 1.

Referring to the figures and more particularly to Figure 1, the purification device according to the invention comprises a drum 1 in the form of a cylindrical tube mounted in rotation on for example two pairs of rollers 2 mounted on a base 8 and of which at least one pair is driven by a motor 3 and a pulley and belt transmission system 4, clearly visible in FIG. 2.

The axis 1a around which the drum 1 rotates, is inclined relative to the horizontal at an angle which is adjusted as a function of the desired speed of advancement of the products substantially along a longitudinal generator of the drum 1, for example , by the threaded feet 26.

As illustrated in Figure 3, the drum 1 consists of a cylindrical tube 5 made for example of stainless steel or any other material, and two rings 6 forming a raceway for the rollers 2, for example aluminum. According to the invention, the cylindrical tube 5 has a multilobed interior cross section, advantageously curvilinear and regular.

This form of cross section has important advantages which will be described later.

According to the invention, the inner surface of the lobes 7 is advantageously glazed.

The device of the invention comprises means for supplying the products to the upper end 1b of the drum 1. These supply means comprise a hopper 9 and an endless belt 10 mounted at the bottom of the hopper 9 and inclined so adjustable by the threaded rod system 10a with respect to the horizontal. The endless belt 10 moves along arrow F, and is advantageously cleaned by a squeegee 11 mounted at a point located downstream of the hopper 9 relative to arrow F and kept in constant contact on the surface of the belt for thus take off the waste or adherent elements entrained by the endless belt 10 and pour them into a bin (not shown).

The purification device comprises a member 12 forming a squeegee extending over the entire length of the drum 1 and being in permanent contact with the interior surface of the drum defined by the lobes 7, and substantially following a generatrix of the upper zone of the drum 1 The squeegee 12 is constituted, for example, by a metal bar 12a connected by uprights 13 to a parallel metal rod 14 for support, the bar 12a is provided on its free edge with a band 21 with elastic property to allow contact easy with the internal surface of the lobes 7. However, this strip 21 must have sufficient rigidity to detach the elements adhering to the internal surface of the lobes 7.

The squeegee 12 is supported at each of its ends by an arm system 15 mounted pivoting about an axis 16 supported by an upright 17 of the frame of the purification machine. The other end of the arms is connected to a rod 18 forming a guide rod by a spring system 19 or counterweight making it possible to constantly apply the elastic band 21 to the internal surface of the lobes 7, or of the drum 1 whatever the shape of this surface.

Of course, this system 15 of arms supporting the squeegee 12 is given simply by way of example, and can be replaced by any system making it possible to maintain the squeegee 12 in constant application on the inner surface of the lobes 7.

The device also comprises a means 20 for collecting the elements detached by the squeegee 12. This means is advantageously constituted by a conveyor belt in the form of a trough, or a vibrating trough, extending below the squeegee 12 over the entire length of the drum 1 and of which at least one end 20a projects outside the drum in order to evacuate the adherent elements peeled off by the squeegee 12 and collect them in a receiving tank not illustrated by means of a squeegee 25.

The frame of the transporter 20 is fixed to the uprights 17 of the frame of the device of the invention.

As illustrated in FIG. 2, the two belt conveyors 10, 20 are driven by the same motor by means of a system of pulleys and belts 22. Furthermore, the belt of the conveyor 20 is maintained, by idle rollers 23 .

To prevent the adhesive elements detached by the squeegee 12 falling outside the conveyor belt 20, deflectors 24 are arranged on either side of the squeegee 12 to form a chute for guiding the adhesive elements detached directly on the conveyor belt 20.

The operation of the device of the invention will now be described, in particular when it is used to purify or clean peas after their mechanical shelling. These peas are fed into the hopper 9 and fall inside the drum 1 by rolling on the inclined endless strip 10. As the inclined strip 10 moves in the opposite direction of movement of the peas, elements having adhesion to the surface of the inclined strip 10 are driven by the latter and separated from the set of peas falling into the drum 1, these adherent elements are collected by means of the squeegee 11.

The drum rotating in the direction indicated by the arrow R, a certain amount of peas are rotated by the lobes 7 over a small distance and automatically fall into a next lower lobe, moreover they progress towards the lower end 1c of the drum 1 by the effect of gravity along a generatrix of said drum 1.

On the contrary, the elements having adhesion properties on the icy surface of the lobes 7, such as for example plant leaves, pods or pod waste, are driven in rotation by the drum 1. Arrived at the level of the doctor blade 12, they are detached from the inner surface of the drum 1 by the band 21 and fall on the conveyor belt 20 then are evacuated outside the drum and collected by means of the squeegee 25.

The adhesion of leaves or pods is often due to the presence of moisture or juices on their surface.

To cause this adhesion, it is possible to humi difier the products fed into the hopper 9 or moisten the inner surface of the lobes 7, by any suitable liquid and in particular with water.

Thus, the method and the device of the invention make it possible to extract a large part of the waste from pods, leaves or other content in the peas fed in the hopper 9.

Thus, the peas collected at the lower end 1c of the drum 1 can be fed directly by the hopper 27 into a purification device with ascending air flow to continue the purification with a good yield and an increased treatment rate as the peas fed into the device are already pre-cleaned, without the risk of clogging the purification device in an ascending air stream or clogging of the sieve device.

Of course, the method and the device of the invention can be used for products other than peas such as for example for the separation of plastic balls from the sheets, threads or other plastic waste. Furthermore, it is easily understandable that the device and the method of the invention can be used not only for pre-cleaning or pre-purifying products but for carrying out complete purification depending on the nature of the products to be separated.

In addition, the shape of the lobes 7 allows better mixing of the products inside the drum and makes it possible to reduce their radial displacement in the drum and is particularly suitable for the treatment of peas. Furthermore, the drum 1 may consist of a single piece, the interior surface of which has been glazed.

Claims (9)

1. Device for purifying by mechanical treatment, products which can move on a surface under the effect of their own weight, such as foodstuffs, for example peas or the like, or granular products, of the type comprising a drum (1) in the form of a cylindrical hollow tube, rotatably mounted about an axis (1a) inclined relative to the horizontal, means for rotating said drum (1), means for feeding the products into said drum (1) at its upper end (1b), means for collecting the purified products at the lower end (1c) of said drum, and means for loosening and _collecting the elements adhering to the inner surface of said drum, characterized in that the inner surface of the drum (1) has a multilobed cross section (7), advantageously curvilinear and regular. 2. Device according to claim 1, characterized in that the interior surface of the aforementioned cylinder is a surface with glazed appearance, preferably a glazed metallic surface. 3. Device according to claim 1 or 2, characterized in that the products to be purified and / or the inner surface of the aforementioned cylinder are moistened before the introduction of the products into the aforementioned drum. 4. Device according to one of claims 1 to 3, characterized in that the aforementioned means for unsticking and collecting the elements adhering to the inner surface of the drum (1) mentioned above comprise a member (12) forming a squeegee, one edge of which is maintained in constant contact with the inner surface of the tam bour (1), substantially along a generator thereof located downstream of the product feed zone with respect to the direction of rotation of the drum, and advantageously at the top of said drum (1), and a member (20t "te3 a conveyor belt or a vibrating trough to collect said detached elements and evacuate them outside the drum (1). 5. Device according to claim 4, characterized in that the aforementioned member (12) forming a squeegee is provided on its edge in contact with the inner surface of the drum (1) with a strip (21) made of a material with property elastic such as, for example, rubber or synthetic material. 6. Device according to claim 5, characterized in that the aforementioned member (12) forming a squeegee is supported at each of its ends by a system (15) of arm mounted pivotally and actuated by at least one spring (19) to maintain the aforementioned strip (21) in constant contact with the inner surface of the drum (1). 7. Device according to one of claims 4 to 6, characterized in that it comprises deflectors (24) defining a chute between the above-mentioned squeegee member (12) and the aforementioned conveyor member (20). 8. Device according to one of claims 1 to 7, characterized in that the aforementioned means for feeding products into the aforementioned drum (1) comprise a hopper (9) for feeding and an endless rotating belt (10 ), said strip (10) being disposed on the lower surface of the hopper (9), and being inclined relative to the horizontal, the strip having a direction of movement (F) opposite to the direction of movement of the pro duits on it. 9. Installation for purifying products such as foodstuffs, for example peas, or granular -products of the type comprising in particular and successively a device for purifying by gravity in an ascending stream of air, a device for sieving products and a washing device, characterized in that it comprises a purification device according to one of claims 1 to 8, disposed before or after said purification device in an ascending stream of air, for pre-cleaning products.

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