EP1524038A1 - Magnetic separator - Google Patents

Abstract

The magnetic separator has an inlet (43) for fluid containing mixture of magnetic and non-magnetic particles. The inlet has a distributor situated in the upstream of a channel (39). The inlet is water tightly connected to the channel at its one end, and connected to a supply pipe (44) at another end. An outlet (50) for magnetic particles has a collector (49) situated at the downstream of the channel.

Description

• un bâti,
• des moyens de canalisation, portés par le bâti, pour définir un circuit d'écoulement pour un fluide entre une entrée de fluide chargé de produit particulaire contenant, en mélange, des particules magnétiques et des particules non magnétiques et des sorties respectivement pour le fluide chargé de particules non magnétiques et pour les particules magnétiques, et
• des moyens d'attraction magnétique, portés par le bâti, pour soumettre le fluide et le produit particulaire à un champ magnétique, de la proximité immédiate de ladite entrée à la proximité immédiate desdites sorties.

The present invention relates to a magnetic separator, of the type comprising:

• a frame,
• channeling means, carried by the frame, for defining a flow path for a fluid between a particulate product-laden fluid inlet containing, in admixture, magnetic particles and non-magnetic particles and outlets respectively for the charged fluid non-magnetic particles and magnetic particles, and
• magnetic attraction means, carried by the frame, for subjecting the fluid and the particulate product to a magnetic field, from the immediate proximity of said inlet to the immediate vicinity of said outlets.

In their current embodiments known, such separators are used to work wet, that is to say on pulps composed a liquid loaded with particulate product containing, in mixing, magnetic particles and non-particles which we wish to separate from one another others, and implement for this purpose a field magnetic low intensity.

• en enrichissement de minerais de fer à base de magnétite ou de pyrotite et autres minéraux magnétiques,
• en purification et épuration de minerais pollués par des produits magnétiques,
• en récupération de magnétite ou de ferrosilicium dans les ateliers de traitement en milieu dense.

Such low-intensity wet magnetic separators are mainly used:

• enriching iron ores based on magnetite or pyrotite and other magnetic minerals,
• in purification and purification of ores polluted by magnetic products,
• in magnetite or ferrosilicon recovery in dense medium treatment plants.

In their current embodiments known, these magnetic separators comprise a tank open to the open, in which the pulp flows between a pulp inlet to be treated, that is to say liquid carrying mixture of magnetic particles and non-magnetic particles, and a pulp outlet treated, that is to say of liquid for the essential discharged magnetic particles and no longer carrying for the most part that non-magnetic particles. Above of the tank is mounted, to the rotation around a horizontal axis relative thereto, a ferrule in non-magnetic material whose lower part bathes in the pulp, inside the tank, and that motor means rotate, depending on the case, in a sense that it moves in the same direction as the pulp inside the tank or in the opposite direction. AT the inside of the lower part of the shell is mounted, fixedly relative to the tank, a circumferential alternation of permanent magnets and polar pieces in which these permanent magnets create magnetic polarities alternately opposite, so that grow between pieces poles adjacent to the field lines that cross the ferrule and tend to stick on it the particles magnetic initially contained in the pulp. These Particles thus separate from the pulp and the ferrule then drives, by friction, in his movement of rotation. The angular position of the alternation of magnets permanent and polar pieces, inside the ferrule, is such that the magnetic particles remain subject to the action of the magnetic field until that they are driven by the ferrule out of the pulp, after which the magnetic attraction ceases and the magnetic particles fall by gravity as well as under the action of the centrifugal force in a hopper towards which they are guided by a suitable deflector.

Such magnetic separators at low intensity, wet, have the advantage of offering a high rate of recovery of magnetic particles in roughing, as well as an optimal purification rate in finishing treatment while allowing flow rates high pulp supply. Typically, as a of non-limiting example, they allow the treatment of pulp containing 20 to 30% solids by weight, with a particle size of these solids between a few tens of micrometers and 5 to 6 millimeters.

However, if they are entirely appropriate to processing of products already in the form of pulp, for example because of treatments they have previously suffered, they require the preparation pulp, by suspending it in water or other liquids, if you want them use for the treatment of products presenting initially dry, which represents a constraint limits the use.

• les moyens de canalisation comportent deux parois verticales et incurvées de façon à présenter une forme convexe d'un côté et concave de l'autre côté lorsqu'elles sont vues en plan, présentant sensiblement une même hauteur uniforme et une même position suivant une direction verticale, à raison d'une paroi extérieure et d'une paroi intérieure longeant, par son côté convexe, la paroi extérieure, par son côté concave, en respectant un espacement continu par rapport à celle-ci, et un fond plat et horizontal, raccordant mutuellement les parois intérieure et extérieure dans une zone d'extrémité inférieure respective pour délimiter avec elles un canal d'écoulement horizontal incurvé, convexe du côté de la paroi extérieure et concave du côté de la paroi intérieure lorsqu'il est vu en plan, les parois intérieure et extérieure et le fond étant fixes par rapport au bâti, réalisés en matériau non magnétique et étanches audit fluide,
• l'entrée de fluide chargé de produit particulaire comporte un distributeur d'entrée situé immédiatement en amont dudit canal en référence à un sens horizontal déterminé de parcours de celui-ci et raccordé, de façon étanche audit fluide, d'une part audit canal, dans une zone d'extrémité amont de celui-ci en référence audit sens de parcours et d'autre part à une conduite d'alimentation en fluide chargé de produit particulaire,
• la sortie pour les particules magnétiques comporte un premier collecteur de sortie situé immédiatement en aval dudit canal en référence audit sens de parcours et raccordé, de façon étanche audit fluide, d'une part audit canal, dans une zone d'extrémité aval de celui-ci en référence audit sens de parcours, et d'autre part à des moyens de collecte des particules magnétiques, dans une zone d'extrémité inférieure, et
• la sortie pour le fluide chargé de particules non magnétiques comporte un deuxième collecteur vertical de sortie, décalé par rapport à la paroi intérieure, du côté concave de celle-ci, dans ladite zone d'extrémité aval dudit canal, et raccordé, de façon étanche audit fluide, d'une part audit canal, immédiatement en amont du premier collecteur en référence audit sens de parcours, et d'autre part à une conduite de reprise de fluide chargé de particules non magnétiques, et
• les moyens d'attraction magnétique longent la paroi extérieure par son côté convexe, à l'extérieur du canal, sensiblement sur ladite hauteur, sensiblement du distributeur d'entrée au deuxième collecteur de sortie en référence audit sens de parcours.

In seeking to develop the application possibilities of low-intensity magnetic separators, the Applicant has been led to deviate completely from known designs, and to create a magnetic separator, of the type indicated in the preamble, which is characterized in that:

• the channeling means comprise two vertical and curved walls so as to have a convex shape on one side and concave on the other side when viewed in plan, having substantially the same uniform height and the same position in a vertical direction , due to an outer wall and an inner wall bordering, by its convex side, the outer wall, by its concave side, respecting a continuous spacing with respect thereto, and a flat and horizontal bottom, connecting mutually the inner and outer walls in a respective lower end zone to delimit with them a horizontal curved flow channel, convex on the side of the outer wall and concave on the side of the inner wall when viewed in plan, the inner and outer walls and the bottom being fixed relative to the frame, made of non-magnetic material and sealed to said fluid,
• the particulate product-laden fluid inlet comprises an inlet distributor located immediately upstream of said channel with reference to a predetermined horizontal direction of travel thereof and sealingly connected to said fluid, on the one hand to said channel, in an upstream end zone thereof with reference to said direction of travel and secondly to a fluid supply line loaded with particulate product,
• the output for the magnetic particles comprises a first output collector situated immediately downstream of said channel with reference to said direction of travel and connected in leaktight manner to said fluid, on the one hand to said channel, in a downstream end zone thereof; ci with reference to said direction of travel, and secondly to means for collecting magnetic particles, in a lower end zone, and
• the outlet for the non-magnetic particle-laden fluid comprises a second vertical outlet manifold, offset from the inner wall, on the concave side thereof, in said downstream end region of said channel, and sealingly connected said fluid, on the one hand to said channel, immediately upstream of the first manifold with reference to said direction of travel, and on the other hand to a fluid recovery line loaded with non-magnetic particles, and
• the magnetic attraction means run along the outer wall by its convex side, outside the channel, substantially on said height, substantially from the inlet distributor to the second outlet manifold with reference to said direction of travel.

It will be observed that in a magnetic separator according to the invention, it is no longer the pulp in circulation surrounding the magnetic attraction means intended to attract magnetic particles but these means of magnetic attraction that surround the pulp in circulation, adding their effects to the particles magnetic to those of the centrifugal force exerted in particularly on these. So, in a separator magnetic circuit according to the invention, the magnetic field and the centrifugal force combine to favor the separation of the magnetic particles, which allows group on the outer wall of the canal a proportion increased of these, in order to route them to the output for magnetic particles, making them slide or roll on this outer wall of the canal.

Even more, in a separator according to the invention, the gravity that is exerted on the magnetic particles, in particular, does not act against force that the magnetic field exerts but, on the contrary, tends to naturally bring back the separated magnetic particles down and to the exit that is assigned to them.

So when the magnetic attraction means are chosen to create a low magnetic field intensity as in the prior art, a separator magnetic device according to the invention has performance even better than magnetic separators at low intensity of the prior art, with space equivalent or lower. Even more, it is possible to give the mutual spacing of the inner walls and outside the channel a sufficiently low value for be compatible with the choice of means of attraction magnetic to create a high magnetic field intensity, whose configuration is shorter than that of a low-intensity magnetic field, while maintaining sufficient efficiency of the magnetic field so created on the entire spacing between the two walls, that is to say the width of the channel.

With equivalent performance, you can still reduce the size of a magnetic separator according to the invention if, according to a preferred embodiment of this one, the distributor and / or the first collector of output and / or the second output collector are vertically and extend substantially over the whole of said height; preferably, it is so at the same time of the entrance distributor and each of the first and second exit manifolds. Thus, the fluid and particles it carries are distributed without turbulence over the entire height of the channel as soon as they enter in it and until they come out of it, which allows the magnetic field to exert its action without disturbances, on almost all of this height even at the beginning and at the end of the canal fluid and particles.

Moreover, we can advantageously predict that the input distributor is of the cyclonic type, which allows to print to the particulate product a force centrifuge that comes to press against the wall outside the canal as soon as it arrives in it, that is to say to submit upon arrival in this channel the magnetic particles it contains to the force exerted by the magnetic field.

In addition, a magnetic separator according to the invention offers unknown possibilities in the art prior to the fluid used for Carry the particulate products to separate.

Indeed, in a magnetic separator according to the invention, it is possible that the means of pipe also include a tight cover fluid audit, of non-magnetic material, flat and horizontal, mutually connecting the inner walls and outer in an upper end zone respective, to close the channel in a sealed manner fluid between said inlet and said outlets.

In other words, a magnetic separator according to the invention lends itself to an embodiment of the means of pipe in form completely fluid tight in question and, in particular, allows to use as fluid as well a gas or gas mixture as a liquid, to practice the separation while the fluid is located overpressure compared to ambient air or depression in relation to it as well as to the ambient pressure, and work with fluids toxic as well as with harmless fluids.

Naturally, the respective positions of the supply line and return line must be adapted to the nature of the fluid carrying the particulate product to be separated.

So when it has a natural tendency to mount, as is the most common case of a gas or a gaseous mixture, for example when it comes to to treat fumes, not only is the channel evolution of the charged fluid is covered so as previously indicated, but also that the supply line and the recovery line respectively open into an end zone inferior of the entrance distributor and in a zone upper end of the second outlet manifold.

When, on the other hand, the fluid carrying the particulate product to be separated has a natural tendency to flowing down, as is the case most fluids, one can foresee or not a tight cover of the channel, although such coverage waterproofing is preferred in such a case, even when is simply to avoid an overflow of the fluid, but it is expected that the feed pipe and the pipe takeover respectively into an area top end of the inlet manifold and in a lower end zone of the second collector of exit.

We could consider that, as in the low intensity separators of the prior art, the magnetic attraction means be stationary by relative to the frame, and that only the flow of the fluid causes the transport of magnetic particles, the along the outer wall, up to the collector corresponding output.

However, to avoid any risk of accumulation of magnetic particles in the channel, in areas of the outer wall corresponding to the gradients higher magnetic field, a mode of realization according to which the means of attraction magnetic means include means for guiding against on the frame, following a closed horizontal trajectory a part runs along the outer wall by its side convex, a continuous and regular alternation, in reference to a circumferential direction of said trajectory, of permanent vertical magnets presenting substantially said uniform height and said position uniform in a vertical direction, two magnets permanent neighbors following the circumferential direction with magnetizations of the same direction and meaning opposite so as to create said magnetic field to within said trajectory, and means for to cause said alternation of permanent magnets continuous along said path in one direction determined training of said direction circumferential with respect to the frame.

Quite surprisingly, we were able to see the tests of a prototype separator magnetic according to the invention that the sense of training alternation of permanent magnets according to their trajectory can not only coincide with the meaning of channel path for the particle-laden fluid, this which seems to be more appropriate in the case of low speeds of movement of the alternation of magnets permanent and a low intensity separation magnetic, but also be opposed to this sense of course, which seems to be particularly suitable for case of high movement speeds of alternation permanent magnets and a higher separation magnetic intensity, but these indications have no limiting character.

The arrangement of permanent magnets to create the magnetic field required in each case can be freely chosen. In particular, magnets can present a circumferential direction magnetization, in reference to the trajectory they accomplish, and two circumferentially adjacent magnets magnetized in opposite meanings, be separated from each other by a pole piece so that it's alternating circumferential polar pieces of polarities opposites that creates inward channel lines of magnetic field, in a manner known in itself in the case of low-intensity magnetic separators the prior art. However, it is preferred that magnets permanent show steering magnetizations perpendicular to said trajectory and that two magnets permanent neighbors following said direction circumferential are magnetically connected to each other, outside said path, by means forming a cylinder head and thus create directly between them the field lines to the inside of the canal.

• les moyens pour guider, par rapport au bâti, ladite alternance d'aimants permanents comportent une virole cylindrique de révolution autour d'un axe vertical du bâti, portant solidairement, vers l'axe, ladite alternance d'aimants permanents, et des moyens de guidage de la virole à la rotation autour de l'axe par rapport au bâti,
• les moyens pour entraíner ladite alternance d'aimants permanents comportent des moyens pour entraíner la virole en rotation autour de l'axe par rapport au bâti, et
• les parois intérieure et extérieure présentent la forme de parties de cylindres de révolution autour de l'axe.

The trajectory followed by the alternation of permanent magnets may have any desired shape, but the choice of a circular shape for this trajectory lends itself to a particularly simple embodiment of the separator according to the invention, this embodiment being characterized in that :

• the means for guiding, relative to the frame, said alternation of permanent magnets comprise a cylindrical shell of revolution about a vertical axis of the frame, integrally bearing, towards the axis, said alternation of permanent magnets, and means of guiding the ferrule to rotation around the axis relative to the frame,
• the means for causing said alternation of permanent magnets comprise means for driving the shell in rotation about the axis relative to the frame, and
• the inner and outer walls have the shape of parts of cylinders of revolution about the axis.

Naturally, when the magnetization of magnets permanent is oriented perpendicular to their trajectory, that is to say in this case radially in reference to the axis of rotation of the ferrule with respect to constructed, this ferrule advantageously constitutes the breech ensuring the magnetic connection between permanent magnets neighbors outside their path.

In addition, a separator according to the invention the permanent magnets creating the magnetic field is move along the flow channel of the loaded fluid particles may be compact and efficiency that is all the greater that we can give to the outer wall of the canal, that is to say on the trajectory that the charged fluid accomplishes between its entry and its output being subjected to the action of the magnetic field, a length very close to that of the trajectory of the alternation of permanent magnets. So, in the case of a circular trajectory of permanent magnets, the outer wall preferably has, with reference to the axis, an angular dimension greater than 180 °, of preferably of the order of 270 °, it being understood that there is instead of keeping some angular development available for entry and exits. In others terms, a magnetic separator according to the invention allows to subject the fluid and the particulate product it charrie to the action of the magnetic field over a distance much larger than in the separators of the prior art, of comparable dimensions.

To facilitate the fall of particles separate magnetic fields, when they manage to immediate proximity to the specifically planned exit for them, the wall is preferably provided outside gradually bends in this direction flow through the particle-laden fluid on the side concave of this wall, that is to say towards the interior of said trajectory in the preferred embodiment, mentioned above, of the separator according to the invention, from the second exit manifold and up to the first output collector, that is to say from the collector output for the mixing of fluid and non-magnetic particles and up to the intended collector for the output of the magnetic particles. Thus, from the second exit collector crossed, the particles separate magnetic fields gradually escape the field magnetic and the action of gravity becomes progressively preponderant on the friction that the force exerted by the magnetic field imposes on magnetic particles, on the outer wall, and that's naturally that magnetic particles get gather in the first output manifold, planned specifically to collect them.

It is preferably provided that the inner wall also gradually bends in the said direction of course, the concave side of this wall, that is to say inward of that trajectory in the case of aforementioned preferred embodiment, starting from the second outlet manifold and up to the first collector of exit.

Thus, magnetic particles are better guided towards the first outlet manifold, intended for they, and the inner wall can advantageously be intended to separate from each other the first and second exit manifolds.

Of course, a certain amount of pulp loaded with non-magnetic particles does not engage in the second exit manifold, provided for this purpose, and reaches the first mixed output manifold with magnetic particles but tests performed in the laboratory, on a prototype separator magnetic circuit according to the invention, have made it possible to demonstrate that this one allowed, in the treatment of the fluid of cutting of high speed machining center, containing ultrafine wear iron, to recover up to more than 80% of the magnetic fraction of the treated particulate product.

Given that particle volume magnetic substances contained in a determined volume of fluid charged with non-magnetic particles and particles magnetic is usually a low proportion, the means of collecting magnetic particles in a particularly form simple, with a well closed by a removable pad in a lower end zone, which is opened periodically to extract the particles magnetic fields, at the cost of a small loss of fluid loaded with non-magnetic particles, but different means of collection, implementing by example of wells with airlock with opening and closing cyclical, could be expected without going out of of the present invention.

Other features and benefits of a magnetic separator according to the present invention will be apparent from the rest of the description, relating to a nonlimiting example of embodiment, as well as attached drawings accompanying this description.

Figure 1 shows a top view of a magnetic separator according to the present invention, the cover of the channel if such a cover is expected, as it is preferred.

Figure 2 shows a view of this separator in part in section with vertical planes marked II-II in Figure 1 (frame and ferrule bearing in this case alternation of permanent magnets), and partly in side elevation in a direction perpendicular to these plans, identified by an arrow not identified in Figure 1 (channel for the loaded fluid, with its distributor entrance and its two exit collectors).

These figures illustrate an embodiment currently preferred because of its great simplicity and the possibility that he offers to answer most needs but other embodiments could be chosen by a person skilled in the art without out of the scope of the present invention, in particular to meet specific needs.

In this embodiment, the separator according to the invention has a general symmetry of revolution around a vertical axis 1 when in position use.

It comprises in particular a frame 2 comprising four vertical columns 3 that are regularly angularly distributed around axis 1 and equidistant from it. These columns 3 correspond in pairs of two columns mutually symmetrical with respect to the axis 1 and arranged according to a same vertical vertical plane, vertical vertical planes 4 and 5 corresponding to the two pairs of columns 3 intersecting at right angles along the axis 1.

Closer to a respective lower end 6 than a respective upper end 7, each column 3 bears integrally, projecting towards the axis 1, a respective console 8 cantilever, having a respective upper face 9 flat and horizontal, the faces 9 of the consoles 8 corresponding to the four columns 3 being mutually coplanar.

Each of the upper faces 9 protrudes upwards, through a respective clevis 10, a respective roller 11 mounted to the rotation, by relative to the respectively corresponding screed 10, around a horizontal axis 12 of the middle plane corresponding respectively 4, 5, the intersecting axes 12 thus perpendicular to the axis 1. The four rollers 11 are mutually identical and three of them are mounted free to rotate about their axis 12 by compared to the corresponding screed 10, while the fourth roller 11 is kinematically linked to means rotational drive about its axis 12, in a defined direction, compared to the clevis 10, these means comprising for example an electric motor 13 mounted in the corresponding column 3.

Because of the identity between the different rollers 11 and the position of their axes 12 in the same horizontal geometric plane, their generators are also placed in the same plane geometric horizontal 14.

Above this geometric plane 14, and more precisely between it and its upper end 7, each of the columns 3 integrally carries two clevises 15, 16 which are located according to the respective average plane 4, 5, respectively closer to the plane 14 than to the upper end 7 and closer to the end 7 than the plane 14. These two clevises 15 and 16 carry, at free rotation around the same axis vertical 17, a respective roller 18, 19.

The axes 17 corresponding to the different columns 3 are located on the same geometric cylinder, of revolution around the axis 1, and the rollers 18, 19 are identical from one column 3 to the other, so that their generators closest to axis 1 are located along the same geometrical cylinder 20, revolution around this axis. rollers 18 corresponding to the four columns 3 are located at the same level, as well as the corresponding rollers 19 to these four columns 3.

The rollers 11, 18, 19 serve to ensure guidance and, as regards the roller 11 associated with the motor 13, the drive of a ferrule 21, of material ferromagnetic such as steel, with rotation around of the axis 1 relative to the frame 2.

For this purpose, the shell 21 has a wall tubular 22 cylindrical of revolution about the axis 1, that is to say delimited, respectively in the sense of a away from it and in the sense of a approximation to it, by one side outer peripheral 23 and a peripheral face inner 24, one and the other cylindrical of revolution around this axis 1.

With reference to this axis 1, the peripheral face 23 has a diameter identical to that of the geometric cylinder 20 while, parallel to this axis 1, it has an unreferenced height greater than the vertical distance separating from plane 14 the rollers 19 closest to the upper ends 7 of the columns 3.

Towards the top, the wall 22 has an edge upper free 25 plane, horizontal while towards the down, it connects solidarily, by one edge lower 26 also flat and horizontal, at a ledge ring 27, of revolution around the axis 1, delimited respectively up and down by one side flat, horizontal 28, 29, and towards the axis 1 by a face inner peripheral 30 cylindrical revolution around this axis 1 with a diameter not referenced less than that of the inner peripheral face 24 of the wall 22, although close to the diameter of this face inner device 24.

The rollers 11 of the consoles 8 are located between the geometric cylinder 20 and a geometric cylinder 31 according to which the peripheral face is arranged interior of the rim 27 which thus rests on the low, by its underside 29, on the generators upper four pebbles 11, according to the plan geometric 14, while the outer peripheral face 23 of the wall 22 of the shell 21 is supported, in the meaning of a distance from the axis 1, on the generators of rollers 18 and 19 closest to the axis 1, according to the geometric cylinder 20.

Towards axis 1, the inner peripheral face 24 of the wall 22 of the ferrule 21 solidarily carries a regular circumferential alternation of magnets 32 permanent and spacers 33 non-material magnetic such as PVC, having the respective shape of vertical chopsticks. Two permanent magnets 32 neighbors in the circumferential direction respective magnetizations of radial direction but of opposite directions so as to present towards axis 1 polarities opposite, so that field lines magnets not shown develop between them on the one hand towards the inside of the shell 21, that is to say towards the axis 1 and secondly in the wall 22 of the ferrule 21, thus playing the role of a connecting yoke magnetically, two by two, permanent magnets 32 circumferentially neighboring. Given the circumferential alternation of permanent magnets 32 having towards the axis 1 opposite polarities extending circumferentially on the entire wall 22 of ferrule 21, circumferential sense field lines opposites alternate circumferentially, to inside the shell 21, forming a field continuous magnet circumferentially. This is in the species of a low-intensity magnetic field, know of an intensity between about 800 to 1800 gauss at a distance of the order of 50 mm to 25 mm permanent magnets 32, in a radial direction in reference to axis 1, these figures being indicated only as a non-limitative example, especially as separator according to the invention is compatible with the use of magnetic fields of intensity higher.

In the vertical direction, permanent magnets 32 and spacers 33 have the same height H, by example of the order of 44 cm, also less than the height of the wall 22 measured between its upper edges 25 and lower 26, and their position is identical, each of them having a lower end not referenced in the immediate vicinity of the face upper rim 27 and an upper end not referenced at a short distance below the edge 25 of the wall 22. For reasons of manufacture, according to the value of the height H, each permanent magnet 32 may be constituted by a butt alignment, parallel to axis 1, of elementary permanent magnets from a height corresponding to a fraction of H, so not shown but easily understandable by a man of career.

Naturally, the alternation of permanent magnets 32 and spacers 33 rotates in the same direction 34 and at the same angular velocity as the ferrule 21, continuously, when the motor 13 is in operation, and it is similarly, field lines generated between magnets permanent 32 neighbors.

In this embodiment of the present invention, permanent magnets 32 and spacers 33 complete a circular trajectory, and their generators closest to axis 1, namely generators of permanent magnets 32, describe a trajectory in the form of a geometric cylinder 35, revolution around axis 1, with a diameter D intermediate between the respective diameters of the geometric cylinders 20 and 31.

The respective numbers, mutually identical, permanent magnets 32 and spacers 33 can be easily determined by a person skilled in the art, depending on of the diameter D of the geometric cylinder 35, to give the magnetic field lines developing between two permanent magnets 32 neighbors a look suitable to the separation of the magnetic particles, this determination being made under conditions similar to those of the prior art. We illustrated a non in which 60 permanent magnets are provided 32 and 60 spacers 33, showing a development respective angle of 3 ° with reference to axis 1, for a value of 570 mm of the diameter D of the cylinder geometric 35.

According to a characteristic aspect of the present invention, it is inside this cylinder geometric 35, that is to say, set back from this one towards the axis 1, that are arranged the means 36 of channeling the fluid carrying the particulate product to separate.

These means 36 are carried in solidarity by the frame 2, namely more precisely by the consoles 8, on the upper side of which they rest by through appropriate holds 37 located at inside the geometric cylinder 31, that is to say in withdrawal from it to axis 1 so as to cross the geometric plane 14 without constituting hindering the rotation of ferrule 21 with respect to frame.

The means 36 are designed to guide the fluid carrying the particulate product to separate the along the geometrical cylinder 35, inside it, in a sense 63 which, in the illustrated example, is opposite to the direction 34 of rotation of the shell 21 relative to to frame 2 and, preferably, as illustrated, on angular development as large as possible in reference to axis 1, namely in this example of the order 270 °.

For this purpose, the channeling means 36 have two walls 37, 38 of non-magnetic material, respectively external and inferior with reference to axis 1, the first of which runs along the geometric cylinder 35, in the immediate vicinity of it, on the aforementioned maximum angular development, for example of the order of 270 °.

Both walls 37 and 38 present the same height H that the permanent magnets 32 and the spacers 33 and occupy the same position as these permanent magnets 32 and spacers 33 in the direction vertical, and each of them presents internally and externally, with reference to axis 1, the shape of a cylindrical part of revolution around of this axis 1, with a respective small thickness relative to their diameter and for example of the same order of size as the thickness of the ferrule of the separators magnetic low intensity of the prior art.

The outer wall 37 externally has a diameter approximately equal to the diameter D, to which it is less than a functional game designed to avoid any risk of friction between the wall 37 and the alternation of permanent magnets 32 and spacers 33 during the rotation of these with the ferrule 21 in the direction 34, about the axis 1, with respect to the frame 2 in case of slight lack of coaxiality. The wall 38 presents it diameters respectively inside and outside, unreferenced, chosen so as to leave between the two walls 37 and 38 a channel 39 of width e constant, with reference to radial directions by compared to axis 1, and low enough for the magnetic field created between two permanent magnets 32 neighbors is effective on the whole of this radial width e. By way of non-limiting example, this may be of the order of 25 mm.

Down, channel 39 is closed by a bottom flat 40, horizontal, which is waterproof to the fluid carrying the particles to be separated, as are also the walls 37 and 38, and which connects to a lower zone respective of the latter, in solidarity and also tight to this fluid. In view of some applications, namely more precisely according to the nature of the fluid carrying the particles to be separated, and more generally in a preferred way whatever this nature and whatever the application, the walls 37 and 38 are mutually connected in one zone respective upper end, by a flat cover, horizontal, 41 which connects to them in solidarity and sealed to this fluid, to which it is itself waterproof; in this case, the channel 39 is sealed, this which allows the separator according to the invention to separate magnetic particles carried by non fluids only liquid, but also gaseous, if any toxic and if necessary under pressure.

Like the walls 37 and 38, the bottom 40 and the 41 possible cover are made of a material not magnetic.

With reference to the direction 63, the walls 37 and 38, of same as the bottom 40 and the possible cover 41, have a respective upstream end zone, corresponding to an upstream end zone 42 of the channel 39, for example in the plane 4, and connect upstream to a respective wall, not referenced, of a vertical distributor 43 for the fluid loaded with particles to separate.

According to the preferred embodiment which has been illustrated, this distributor 43 extends over the whole of the height H, essentially recessed towards the axis 1 relative to the wall 38, and constitutes a distributor Cyclonic vertical axis 44, located between the zone upstream end 42 of the channel 39 and the axis 1, so as to communicate with fluid and particles entering the channel 39 a centrifugal effect with reference to axis 44 as well as to axis 1 in order, in particular, to tend to flatten the particles to separate against the wall 37 of channel 39. For this purpose, when seen in plan, the dispenser 43 has the shape of a volute that starts widening in one direction of rotation 45, around the axis 44, corresponding to the direction of rotation 34 around axis 1 until connected to the zone upstream end 42 of the channel 39 along the plane 4.

Upward when the fluid carries the particles to be separated is a liquid, as it is illustrated, that is to say in an end zone upper located at the lid 41 possible or above it, the distributor 43 is connected, by the narrowest area of the volute, to a driving 46 fluid supply charged with particles to separate, which is fixed as the distributor 43 by relative to the frame 2 of the separator. It can be the same whenever the fluid carries the particles to separating is heavier than the ambient air, or if it is overpressure compared to this one, whatever by elsewhere its nature. When the fluid carries the particles to be separated is lighter than the ambient air, as is the case most often when it comes to a gas or a gaseous mixture or, whatever its nature, when under pressure, driving power supply can be connected not to a zone top end of the dispenser 43, but at a lower end zone of it, below the bottom 40, as shown schematically in 47 in Figure 2.

After being admitted to canal 39 by the upstream end zone 42 thereof, the loaded fluid particles to be separated through the channel 39 in the sense 63, in which it flows against the field magnetic emitted by the alternation of permanent magnets 32, which captures the magnetic particles to flatten them on the wall 37, on which these magnetic particles move by sliding in the direction 63 under the action of the displacement of the charged fluid in this direction inside of channel 39 and / or rolling while cooperating with the field magnetic rotating in the manner of a pinion with a gear wheel in a gear.

The fluid is thus gradually discharged from its magnetic particles as and when its channel 39 and in a downstream end zone 48 of the latter in reference to meaning 63, corresponding to a downstream end zone of the walls 37 and 38, the bottom 40 and if necessary of the cover 41, we collect separately by means of a respective manifold 49, 50, fixed relative to the frame 2 of the separator, on the one hand the separate magnetic particles and secondly the fluid which is only loaded with non-magnetic particles, at least for the most part.

The angular development of channel 39 in reference to axis 1 is as close as possible to 360 °, without limitation other than the need to provide sufficient space to dispose collectors 49 and 50 exit next to the dispenser 43, inside the geometric cylinder 35, in order to make the separation magnetic as effective as possible; in the example illustrated, this angular development is of the order of 270 °, namely more precisely a little more than 270 ° between the inlet distributor 43 and the collector 49 of recovery of magnetic particles and a little less 270 ° between the inlet distributor 43 and the collector 50 fluid loaded exclusively or roughly exclusively non-magnetic particles. More precisely, the collectors 49 and 50 have an axis respective vertical 51, 52 and, although these two collectors 49 and 50 are mutually adjacent, their axes 51 and 52 are respectively disposed of and else of plan 5, namely more precisely a half-plane 53 delimited by axis 1 and corresponding to this plan 5, shifted 270 ° in the direction 63 relative to a half-plane 54 delimited by the axis 1 and corresponding to the part of the plane 4 containing the axis 44 of the inlet distributor 43 as well as the upstream end zone 42 of the channel 39.

Immediately upstream of the half-plane 53 in reference to direction 63, the outer wall 37 of channel 39 begins to gradually bend in the direction of a approach towards Axis 1 while remaining parallel to this one, and this deflection is accentuated downstream of the half-plane 53 with reference to the direction 63, although that the magnetic particles retained on this wall 37 by the magnetic field generated by the alternation permanent magnets 32 and brought thereby by the flow of the charged fluid in the direction 63 and / or by rolling on this wall 37 are gradually escaping this magnetic field and, thus, fall by gravity towards the bottom 40 of the channel 39.

This shift continues to an area downstream end of the wall 37, with reference to direction 63, downstream end zone through which the wall 37 connected to a wall 55, vertical, of the collector 49. This wall 55 is semicylindrical of revolution around of the axis 51, which is shifted towards the axis 1 relative to the wall 37 in its downstream end zone as well as by relative to the geometric cylinder 35, and it extends over the entire dimension H by connecting to the wall 37, at a downstream end zone of the wall 38, reference to direction 63, as well as to bottom 40 and to the cover eventual 41 in a fluid-tight manner carrying the particles to be separated, to which it is itself waterproof. Like the wall 37, the wall 38 bends gradually towards axis 1 while remaining parallel to this one, an area slightly upstream of the half-plane 53 with reference to direction 34, at its end zone downstream, located slightly downstream of this half-plane 53 in reference to sense 34, and its deflection is more pronounced as that of the wall 37 so well approximately from plane 53, the spacing mutual walls 37 and 38 in a radial direction with reference to axis 1 is gradually increasing to connecting the two walls 37 and 38 to the wall 55 of the collector 49.

When they reach the latter, the particles have totally escaped the action of the field Magnetic generated by the alternation of permanent magnets 32, so that they tend by gravity to gather in a lower end zone of the collector 49, at bottom level 40 of channel 39.

Through this lower end, the collector 49 connects through an unreferenced hole in the bottom 40 of the channel 39, in a fluid-tight manner carrying the particles to be separated, to a vertical well 56 for collecting magnetic particles, which is thus placed at a lower than that of the bottom 40, within the geometric cylinder 31, and is closed down, from fluid-tight way carrying the particles to separate, by a removable pad 57 that can be opened regularly to extract from the well 56 the particles magnetic data collected in the latter. Naturally, this collection method assumes that particle amounts magnetic data collected for a definite time remain relatively low, and other means of collection could be provided in particular in the case of larger amounts of magnetic particles by unit of time.

In a particularly simple and economical way, the part of the wall 38, close to its end zone downstream with reference to sense 63, which bends gradually in this direction towards axis 1 constitutes a separation, fluid-tight carrying the particles to separate, between the collector 49 of the particles separated magnetic and the collector 50 of the fluid carrying almost exclusively non-particulate matter magnetic, and has the shape of a part of cylinder of revolution around the axis 52, which is closer to axis 1 than axis 51.

This part of the wall 38 which is thus cylinder of revolution around the axis 52 presents a diameter smaller than the rest of the wall 38 but greater than that of the wall 55. The inflected part of the wall 38 has approximately the shape of a quarter cylinder of revolution around the axis 52 and connects downstream, with reference to direction 63, to a concave wall 58 of the collector 50, which has a approximately hemicylindrical shape of revolution around the axis 52 with a diameter identical to that of the inflected part of the wall 38, that the wall 58 so prolongs.

In contrast to its connection with the party inflected from the wall 58, in a direction circumferential with reference to the axis 52, the wall 58 is reconnects to the wall 38, namely by via a convex wall 59 in the direction 63.

The walls 58 and 59 are fluid-tight carrying the particles to be separated, extend over the all of the height H and connect so sealed to this fluid on the one hand at the bottom 40 and the lid 24 and between them and, respectively, to the inflected part of the wall 38 and to the rest of this wall 38.

Between the wall 59 and its inflected part, the wall 38 presents on the whole of dimension H, between the bottom 40 and the cover 41, if any, interrupt 60 by which the fluid loaded almost exclusively non-magnetic material arrives inside the collector 50, that is to say of a defined volume, around the axis 52, by the part inflected wall 38 and wall 58.

The collector 50, thus placed in communication by the interruption 60 of the wall 38 with the channel 39, to which it is thus connected in a fluid-tight manner carrying the particles to be separated, is moreover connected, also tightly to this fluid, to a conduit 61 for taking up the fluid loaded with non-particles magnetic.

Following a vertical direction, as it is illustrated, the conduit 61 for taking up the loaded fluid almost exclusively non-magnetic particles is located opposite the supply line 46 fluid loaded with magnetic particles and not to separate, the respective positions of these however, two lines are dictated more general nature of the fluid in question as well as by the pressure to which he is in comparison with the ambient air.

So, in the example shown, while the supply line 46 connects to the dispenser 43 by an upper end zone of this one, through the possible cover 41, it is at a lower end region of the collector 50 that the duct 61 connects, namely through the bottom 40. Immediately below it, at his connection with the lower end zone of the collector 50, the pipe 61 has the shape of a funnel of revolution around the axis 52, convergent down.

When, as schematized in 47, the fluid supply line loaded with particles to separate is connected to the distributor 43 by a zone lower end thereof, through the bottom 40, it's usually at an upper end zone of collector 50, through the cover 41, if any, then generally necessary, that the recovery conduct of the fluid essentially charged only particles not magnetic connects, namely via of a hood converging upwards as we have schematized at 62 in Figure 2.

Naturally, as a small proportion magnetic particles initially present in the fluid introduced by the distributor 43 into the channel 39 can remain in the fluid thus evacuated by through the collector 50, the collector 49, when it is opened, lets out fluid loaded with non-magnetic particles, but the proportion of non-magnetic particles mixed with particles magnetic when collecting these is minimal, i.e., little affects the efficiency of the separator according to the invention in terms of particle separation magnetic properties vis-à-vis non-magnetic particles.

One skilled in the art will readily understand that, well that the embodiment of the separator according to the invention that has been described is currently preferred, especially because of its great simplicity, other embodiments could also be chosen without going beyond the scope of the present invention. In particular, we would not go out within the scope of the present invention by having the alternation of permanent magnets 32, then suitably worn and guided, a trajectory horizontal other than circular, provided that alternation of permanent magnets 32 would be turned towards within this trajectory, and that this would be lengthened by a wall, made of non-magnetic material, circulation channel, in the same or opposite direction, depending on the case, in the sense of course of the trajectory in question, for the fluid carrying the particles magnetic and non-magnetic inlet distributor for this fluid, carrying these mixed particles, and outlet manifolds respectively for the magnetic particles and for the fluid charged with non-magnetic particles.

Claims (19)

Magnetic separator, of the type comprising: a frame (2), channeling means (36), carried by the frame (2), for defining a flow path for a fluid between a particulate product-laden fluid inlet (43) containing, in admixture, magnetic particles and non-particulates; magnets and outlets (50, 49) respectively for the non-magnetic particle-laden fluid and the magnetic particles, and magnetic attraction means (32, 33), carried by the frame (2), for subjecting the fluid and the particulate product to a magnetic field, from the immediate proximity of said inlet (43) to the immediate vicinity of said outlets ( 49, 50), characterized in that the channeling means (36) comprise two walls (37, 38) vertical and curved so as to have a convex shape on one side and concave on the other side when viewed in plan, having substantially the same uniform height (H) and the same position in a vertical direction, due to an outer wall (37) and an inner wall (38) along its convex side, the outer wall (37), by its concave side, maintaining a continuous spacing (e) therefrom, and a flat, horizontal bottom (40) mutually connecting the inner (38) and outer (37) walls in a respective lower end region to delimit with them. a curved horizontal flow channel (39), convex on the side of the outer wall and concave on the inner wall side when viewed in plan, the inner and outer walls (37, 38) and the bottom (40). being fixed relative to the frame (2), made in non-magnetic material and sealed to said fluid, the particulate product-laden fluid inlet (43) comprises an inlet distributor (43) located immediately upstream of said channel (39) with reference to a determined horizontal direction (63) thereof and connected, sealingly to said fluid, on the one hand to said channel (39), in an upstream end region (42) thereof with reference to said direction of travel (63) and on the other hand to a conduit (44, 47 ) of fluid feed loaded with particulate product, the outlet (49) for the magnetic particles comprises a first outlet manifold (49) located immediately downstream of said channel (39) with respect to said direction of travel (63) and connected in leaktight manner to said fluid, on the one hand said channel (39), in a downstream end region (48) thereof with reference to said direction of travel (63), and secondly at means (56, 57) for collecting the magnetic particles, in a lower end zone, and the outlet (50) for the non-magnetic particle-laden fluid comprises a second vertical outlet manifold (50) offset from the inner wall (38) on the concave side thereof in said downstream end region (48) of said channel (39), and sealingly connected to said fluid, on the one hand to said channel (39), immediately upstream of the first manifold (49) with reference to said direction of travel (63), and on the other hand to a line (61, 62) for taking up fluid loaded with non-magnetic particles, and the means (32, 33) of magnetic attraction run along the outer wall (37) by its convex side, outside the channel (39), substantially on said height (H), substantially of the inlet distributor (43) at the second outlet manifold (50) with reference to said direction of travel (63). Separator according to claim 1, characterized in that the distributor (43) and / or the first outlet manifold (49) and / or the second outlet manifold (50) are vertical and extend substantially over the whole of said height (H). Separator according to either one of Claims 1 and 2, characterized in that the magnetic attraction means (32, 33) are chosen from a group comprising the means for creating a low-intensity magnetic field and the means for creating a field magnetic high intensity inside the channel (39). Separator according to any one of Claims 1 to 3, characterized in that the magnetic attraction means (11, 13, 18, 19, 21, 32, 33) comprise means (11, 18, 19, 21) for guiding with respect to the frame (2), following a closed horizontal path (35), a portion of which runs along the outer wall (37) by its convex side, a continuous and regular alternation, with reference to a circumferential direction of said path (35) vertical permanent magnets (32) having substantially said uniform height (H) and said uniform position in a vertical direction, two adjacent permanent magnets (32) in the circumferential direction having magnetizations of the same direction and opposite direction so as to creating said magnetic field within said path (35), and means (13) for driving said alternation of permanent magnets (32) continuously, along said path (35), in a direction of driving. determined (34) of said circumferential direction relative to the frame (2). Separator according to claim 4, characterized in that the direction of travel (63) and the direction of drive (34) coincide. Separator according to claim 4, characterized in that the direction of travel (63) and the direction of drive (34) are mutually opposite. Separator according to any one of claims 4 to 6, characterized in that the permanent magnets (32) have magnetizations of direction perpendicular to said path and in that two adjacent permanent magnets (32) in said circumferential direction are magnetically connected between they, outside said path, by means (21) forming a cylinder head. Magnetic separator according to one of Claims 4 to 7, characterized in that : said trajectory (35) is circular, the means (11, 18, 19, 21) for guiding, relative to the frame (2), said alternation of permanent magnets (32) comprise a shell (21) cylindrical of revolution about a vertical axis (1) of frame (2), integrally supporting, towards the axis (1), said alternation of permanent magnets (32), and means (11, 18, 19) for guiding the ferrule (21) to the rotation around the axis (1) relative to the frame (2), the means (13) for causing said alternation of permanent magnets (32) comprise means (13) for driving the shell (21) in rotation about the axis (1) relative to the frame (2), and the inner (38) and outer (37) walls have the shape of parts of cylinders of revolution about the axis (1). Separator according to claim 8 in its dependence relation to claim 7, characterized in that the shell (21) constitutes said means (21) forming a cylinder head. Magnetic separator according to any one of claims 4 to 9, characterized in that the outer wall (37) runs along said path (35) over most of the length thereof. Magnetic separator according to Claim 10 in its dependence relation to any one of Claims 8 and 9, characterized in that the outer wall (37) has an angular dimension with reference to the axis (1). greater than 180 °, preferably of the order of 270 °. Magnetic separator according to any one of claims 1 to 11, characterized in that the channeling means (36) further comprises a cover (41) sealed to said fluid, non-magnetic material, flat and horizontal, mutually connecting the inner walls (38) and outer (37) in a respective upper end region, for sealing the channel (39) to said fluid between said inlet (43) and said outlets (49, 50). Magnetic separator according to Claim 12, characterized in that the supply line (47) and the return line (62) open respectively into a lower end region of the inlet distributor (43) and into a zone of upper end of the second outlet manifold (50). Magnetic separator according to one of Claims 1 to 13, characterized in that the supply line (46) and the return line (61) open respectively into an upper end region of the inlet distributor (43). and in a lower end region of the second output manifold (50). Magnetic separator according to any one of claims 1 to 14, characterized in that the outer wall (38) gradually bends on the concave side thereof, in said direction of travel (63), from the second collector of output (50) and to the first output collector (49). Magnetic separator according to claim 15, characterized in that the inner wall (38) progressively bends on the concave side thereof in said direction of travel (63) from the second outlet manifold (50) to to the first output manifold (49). Magnetic separator according to claim 16, characterized in that the inner wall (38) separates the first and second output collectors (49, 50) from each other. Magnetic separator according to any one of claims 1 to 17, characterized in that the means (56, 57) for collecting the magnetic particles comprise a well (56) closed by a buffer (57) removable in a lower end zone . Magnetic separator according to any one of Claims 1 to 18, characterized in that the inlet distributor (43) is of the cyclonic type.

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