FR2887471A1 - Magnetic device to eliminate ferrous particles in a circuit transported fluid comprises a cylindrical tank having an external partition wall comprising two recess arranged vertically in a bar magnet, and a filtration system - Google Patents

Abstract

In the magnetic device, a cylindrical tank (1) is connected to a circuit by conduit (14) and is made up of non-magnetic materials. A removable bar magnet (10) has a length equal to conduit height. The conduit inlet (7) opens in higher part of the tank and the conduit outlet (8) opens in lower part of the tank in a direction of horizontal tangential to the wall. The conduits are disposed together for prolongation of their axis in a helicoid curve. In the magnetic device, a cylindrical tank (1) is connected to a circuit by conduit (14) and is made up of non-magnetic materials. A removable bar magnet (10) has a length equal to conduit height. The conduit inlet (7) opens in higher part of the tank and the conduit outlet (8) opens in lower part of the tank in a direction of horizontal tangential to the wall. The conduits are disposed together for prolongation of their axis in a helicoid curve. The recess has depth higher than the thickness of internal partition wall (6) in a vertical line of the tank. The bar magnet is placed in recess by a movable fixer and is mounted on a fixed articulated support of the tank to maintain the recess in distance. A filtering system is placed at the lower part of the tank to filter sludge and particles that are indifferent to magnetic field. The bottom of the tank is in a convex shape to collect the sludge and particles. A movable lid is palced on the upper wall of the tank and is fixed to the side wall (4) in a watertight condition. An independent claim is included for process to eliminate ferrous particles in a transported fluid.

Description

2887471 1

MAGNETIC EXTRACTION DEVICE

  OF PARTICLES SUSPENDED IN A FLUID

  The present invention belongs to the field of the treatment of fluids, in particular industrial or domestic aqueous fluids, with a view to the elimination of particles in suspension.

  The present invention relates to a device for removing metal particles present in industrial or domestic fluids, taking advantage of the properties of magnets to attract iron and some other metals.

  Water is commonly used as a working fluid flowing through pipes, pipes or pipes from one point to another. It often contains impurities that can be troublesome, especially if, as in the case of closed circuits, these impurities accumulate in the process. For example, industrial water pumped into groundwater contains sludge as well as various pollutions, such as suspended metal particles. The fluids used for the surface treatment, meanwhile, are loaded with impurities during their use.

  Another case is that of sanitary water that oxidizes the metal components of the circuit. The formed metal oxides, which are very friable, are easily detached from the component walls and are gradually carried into the circuit water as debris and suspended particles. Depending on the pH of the water, they can give rise to metal hydroxides that precipitate to form sludge. Suspended solids and water-borne sludges accumulate at various points in the circuit, preferably where surface roughness, linearity breaks, or low velocity areas occur.

  These accumulations, in addition to causing clogging and clogging of the pipes, are a source of disturbances for thermal exchanges and the continuity of the hydraulic regimes. The impurities must be eliminated, this operation being all the more necessary that we work in a closed circuit. Various systems have been proposed to extract ferrous metals, which use the attraction properties of iron particles by magnets.

  For example, there is known a device comprising a tank installed as a bypass on the return piping of a heating network. Four magnetized bars are placed in the reservoir through which the heating water passes and collect the iron particles in suspension. When the magnets are covered with filings, they must be disassembled and scraped heavily to remove the iron particles that are clumped together.

  The application FR 2 793 427 describes a device comprising a vessel through which a fluid flows and a thimble, part of which is inside the vessel. The thermowell contains a magnetic bar which can either be in the lower position in the tank or in the upper position out of the tank. The fluid enters the lower part of the tank and leaves at the top under the action of a pump.

  Such devices have several disadvantages. On the one hand they require the use of a pump to ensure the circulation of the fluid. On the other hand, the fluid to be treated occupies the entire space of the tank and is not subjected to any agitation, while the magnetic field is sensitive only to the vicinity of the magnet (the high-power magnets are reserved for very special applications given their cost). The fluid is therefore not subject to the action of the magnet in a homogeneous and effective manner.

  The present invention aims to provide a solution to this problem through a powerful device with a magnetic system for collecting and evacuating iron particles.

  The requirements for such a device are multiple. In the first place, an increased efficiency of the removal of particles in suspension is sought. Another quality lies in the easy cleaning of the particle collection elements, which allows regular maintenance and avoids saturation phenomena.

  Beyond these particular requirements, it will be appreciated in the device object of the present invention reliability, robustness, compactness, which give it an exceptional life at a moderate cost compared to the benefits it provides.

  Thus, the present invention relates to a device for removing ferrous particles suspended in a fluid transported in a circuit. It comprises a cylindrical vessel having a bottom, an upper wall and a side wall having an outer wall and an inner wall, said tank being connected to said circuit by an inlet duct and an outlet duct. The device is characterized in that the outer wall of the side wall comprises at least one recess in which is vertically housed at least one magnetic bar.

  Preferably, in the device according to the invention, the outer wall of the side wall comprises two recesses placed on either side of the tank, in each of which is housed a magnetic bar. For the sake of simplicity and general consistency, will be described hereinafter only a device comprising two magnetized bars. It will be readily understood from a reading of the following that a device having a different number of magnetized bars will operate according to the same principle, and that the person skilled in the art will have no difficulty in adapting the device thus described to the case a single bar or in the case of three, four or more bars, these cases being expressly included in the

this description.

  The device according to the invention is therefore like a metal tank, which is installed on a circuit in which a fluid capable of containing suspended particles, and in particular iron particles, is transported. It can be an open circuit, for example for pumping a water table, feeding a surface treatment device, or a closed circuit such as a circulation circuit of the water. 'hot water. The fluid is usually water in which different materials, naturally occurring or not, are in suspension. The device according to the invention can be used to treat other fluids that may contain ferrous particles.

  The device which is the subject of the invention is installed in an easily accessible place by means of a suitable fastening means such as, for example, a base placed on the ground or a wall seal, and is connected to said circuit by an air duct. entrance and an exit duct. The tank takes the form of a cylinder, closed by a bottom in its lower part and by a wall in its upper part. The side wall consists of a double wall, which provides rigidity and thermal insulation, and which accommodates the magnetized bars in its thickness. Indeed, the outer wall of the side wall comprises in two locations, preferably symmetrically opposed, recesses in each of which is housed a magnetic bar. These recesses have an elongated shape corresponding to the size of the magnetized bars and are arranged vertically along the tank.

  Thus the fluid that enters the tank and the cross is subjected to the magnetic field exerted by the magnets. As a result, the iron particles are attracted to the inner wall and stick together in the vicinity of the magnets. Thanks to the indentations in the wall, the magnets are at a minimal distance from the fluid which effectively undergoes their magnetic attraction. 30 35

  Advantageously, said magnetized bars have a length at least equal to the height between the inlet duct and the outlet duct. Thus, the capture of ferrous particles takes place over the entire height of the tank.

  According to a particularly preferred characteristic, the tank is made of non-magnetic materials, for example stainless steel or aluminum, this characteristic being the corollary of perfect operation of the entire device.

  According to an advantageous characteristic of the device according to the invention, the inlet conduit of the fluid opens into the upper part of the vessel in a substantially horizontal direction tangential to the wall. In this way, the fluid entering the tank with a certain speed and undergoing a centrifugal thrust, it flows continuously against the internal partition with a circular movement descending gradually, that is to say along a helical path. It is evacuated as and when the tank fills. The fluid thus flows essentially against the wall by passing many times in front of the magnets, in a layer of a thickness of a few centimeters at most.

  It will be understood that this characteristic relating to the arrangement of the inlet duct is particularly advantageous when it is known that the magnetic field of a 6000 gauss magnet is practically no longer sensitive beyond fifteen centimeters, its effectiveness being already very reduced to a few centimeters. The device according to the invention therefore makes it possible to subject all the fluid passing through the tank to a magnetic field high enough to have a significant effect on it, and this on multiple occasions, and thus to capture all the ferrous particles in suspension in the fluid.

  Another effect of the helical movement of the fluid in the tank is that the centrifugal force tends to bring the heavier elements, which are precisely the metal particles and the sludges which it is generally desired to eliminate, to the wall, and especially the debris of iron. These are all the better captured by passing in the vicinity of the magnets.

  According to an advantageous embodiment of the device according to the invention, the outlet duct opens in the lower part of the tank in a substantially horizontal direction tangential to the wall. This arrangement allows a rapid evacuation of the fluid which can thus continue its movement without turbulence at the outlet of the vessel.

  According to another advantageous characteristic of the invention, the inlet duct and the outlet duct are arranged relative to one another so that their axis is in the extension of the same helical curve. When the various adjustments are made, especially concerning the fluid inlet speed, the fluid flows in a liquid band of width proportional to the section of the inlet duct and describes a number of revolutions in the tank, then the liquid band ends its gradual descent at the outlet of the vessel through which it evacuates without breaking the path, further improving the smooth and continuous fluid flow.

  According to an advantageous characteristic of the invention, the recesses accommodating the magnetized bars have a depth greater than the thickness of the lateral wall so that the internal partition has two vertical ripples protruding into the internal volume of the vessel. The interest of this is not so much related to a search for compactness of the device as the effect obtained on the flow dynamics of the fluid against the internal partition. Indeed, the inflection of the wall at the level of a wrinkle causes a disturbance in the path of the fluid which results in localized turbulence in the hollow areas on either side of the wrinkle. As a result, the fluid stays longer in the immediate vicinity of the magnet, further increasing the efficiency of the extraction.

  The device according to the invention may further comprise a sludge filtration system and particles indifferent to the magnetic field, placed in the lower part of the tank. It is advantageous to combine the extraction of iron particles with that of other metal particles and sludge present in the fluid. For example, a filter basket of calibrated porosity as known to those skilled in the art, allows the finishing of the treatment by the elimination of insensitive particles to the effect of magnets.

  Other features of the device according to the invention may advantageously be implemented, in particular to facilitate its use and its maintenance. In particular it is essential that the particles captured by the magnets can then be easily extracted. Therefore, the magnetized bars are preferably removable bars held in place in their respective recess by a movable attachment means. Such a fixing means may be a detachable tab held by a screw, a clipping system, or other that the skilled person will choose from the many known techniques.

  According to an interesting variant of execution, each of the magnetized bars can be mounted on an articulated support fixed to the tank, able to maintain said bar in its recess or at a distance from it, depending on whether the device is in operation or in a extraction phase of the captured particles. For example, a support fixed to the outer wall 2887471 6 of the wall by two hinges and associated with a spacer rod for moving the magnet at a distance of about 10 to 20 cm from the wall, is used in order to cancel the magnetic field in the tank. The iron particles agglutinated against the internal partition are no longer subjected to their own weight and are detached themselves or by a slight friction (a manual wiping or a water drive being possible for example).

  According to a preferred characteristic, the bottom of the tank has a convex shape favoring the collection of sludge and particles indifferent to the magnetic field.

  According to another characteristic, the tank is equipped with an upper water intake pipe, a degassing vent and a low discharge valve. These devices are well known in themselves to the skilled person who will find no difficulty in achieving them. The upper intake line is used to inject water from the top of the tank to drive the particles to the low valve during the extraction phase of the particles and sludge from the tank. The different valves can be simple manual valves or if it is desired to automate the device, they can be replaced by solenoid valves.

  Preferably, the upper wall of the tank is a movable cover adapted to be sealingly attached to the side wall, so that access to the interior of the tank is possible if necessary.

  Another object of the present invention relates to a method of removing particles suspended in a fluid transported in a circuit, implementing the treatment device described above. The method according to the invention essentially comprises the steps of: passing said fluid through a device according to the invention, whose inlet duct and outlet duct are connected to said circuit and, after a period of operation, isolating the tank by means of valves placed upstream and downstream thereof, moving said at least one magnet away from the tank until the effects of the magnetic field on the particles of iron agglutinated against the partition disappear internal to the vicinity of said at least one magnet, -extract from the tank the particles released from the magnetic attraction.

  For the reasons already explained, the present description will relate to a method in which a vessel equipped with two magnets is used. Nevertheless, it is specified that the process according to the invention can be carried out with only one or with several magnetized bars and that the present description expressly includes these variant embodiments. 15 20

  According to a preferred feature of the method according to the invention, the fluid enters the upper part of the tank in a substantially horizontal direction tangential to the wall. Its speed is sufficient to initiate a circular motion of the fluid which continues by describing a substantially helical downward trajectory, reminiscent of a vortex. The entry speed of the fluid is advantageously between 1.5 m / s and 2 mis. The residence time of the fluid in the tank is thus at least 20 seconds, preferably between about 20 seconds and 60 seconds.

  According to another preferred feature of the method according to the invention, the fluid is evacuated by the lower part of the tank in a substantially horizontal direction tangential to the wall.

  According to yet another preferred feature of the method according to the invention, the fluid flows in the tank in a substantially helical path against the internal partition. The outlet duct can be placed judiciously so as not to interrupt the continuity of the vortex.

  According to a particularly preferred characteristic, the inlet flow rate of the fluid in the tank is adjusted in such a way that a narrower fluid band is formed than the pitch of the helical path. For a given inlet duct section, the inlet flow rate in the vessel imposes the fluid velocity. The flow rate is therefore the adjustment parameter of the speed / section relation. The sizing of the tanks and ducts is designed to correspond to the usual operating values of the circuits to be treated. An inlet valve may optionally allow fine adjustment within a usual range.

  When the fluid flows in a narrower band than the pitch of the helical path, so that the turns of the fluid do not overlap, an even better quality of magnetic pickup is obtained. Indeed, in the stationary operating phase, the fluid always occupies approximately the same position, which defines a sequential vortex having a fluid flow band and a "dry" intermediate band. The fluid band, not very thick in its central part, is very thin at the edge, which further favors the magnetic attraction. However, it has been found that the particles are deposited preferentially at the edge of the flow band and accumulate on the dry band where they can no longer be torn off by the flowing fluid.

  According to an interesting feature of the claimed process, the residence time of the fluid 2887471 8 in the vicinity of the magnetized bars is increased by a vertical wrinkle protruding into the internal volume of the vessel in the vicinity of each magnet.

  Preferably, sludge and particles indifferent to the magnetic field are collected in the lower part of the tank, for example using a calibrated filter basket.

  In the extraction phase out of the tank sludge and particles, the magnets are removed from their recess, which produces a collapse of the particles agglomerated on the inner wall and facilitates their evacuation. Conveniently, all the particles captured by the magnets or deposited at the bottom of the tank and the sludge are entrained out of the tank by a stream of water admitted into the tank through the upper pipe and flowing through the evacuation valve. low.

  Once these operations are completed, the magnets are placed back into their respective recesses, the valves are put back into their previous position. The device that is the subject of the invention is ready to extract the iron particles again from the fluid passing through it.

  The present invention will be better understood and its advantages will appear more clearly on reading the following examples and accompanying figures.

  Figure 1 shows the device according to the invention in vertical section, with its two magnetic bars.

  Figure 2 shows the same device in horizontal section along the axis AA '.

  The device 100 for eliminating ferrous particles in suspension in a fluid according to the example comprises the cylindrical vessel 1 having the bottom 2 having a domed shape, the upper wall 3 and the side wall 4. This comprises the partition external wall 5 and the internal wall 6. The external wall 5 of the side wall 4 comprises the recesses 9 in which the magnetized bars 10 are housed vertically. The upper wall 3 of the tank is a removable cover fixed to the counter-flange 21 of the wall 4 by the bolts and nuts 22. The seal 23 seals.

  The tank 1, placed on the ground on the base 18, is made of non-magnetic materials, mainly stainless steel. It is connected to the fluidic circuit via the inlet duct 7 and the outlet duct 8. It is equipped with the upper water intake duct 14 and the low discharge valve (15). A degassing vent (not shown) is also provided.

  The magnetized bars 10 are cylindrical and have a length greater than the height between the inlet duct 7 and the outlet duct 8. They are made of neodymium carbide and generate a magnetic induction of the order of 5 800 gauss at 6. 000 gauss. They are shown in Figures 1 and 2 out of their homes. When the device is in operation, they are placed in the recesses 10 and are held there by the tab 19 blocked by the screw 20.

  The inlet duct 7 opens into the upper part of the tank 1 in a horizontal direction tangential to the wall 4. Similarly, the outlet duct 8 opens in the lower part of the tank 1 in a horizontal direction tangential to the wall 4. As it appears in Figure 2, the relative position of the two ducts is such that their axis is in the extension of the same helical curve so as not to interrupt the continuity of the vortex. The inlet and outlet ducts 7 and 8 have an inside diameter of 10 cm. (Check) The recesses 9 accommodating the magnetized bars 10 have a depth greater than the thickness of the side wall 4 so that the internal partition 6 has two vertical ripples protruding into the internal volume of the vessel 1.

  The filtering basket 13 of sludge and particles indifferent to the magnetic field, of calibrated porosity, is placed in the lower part of the tank 1.

  The device illustrated here allows the implementation of the device according to the invention under the following conditions, comprising the steps of: - passing the fluid through the device 100, including the inlet duct 7 and the outlet duct 8 are connected to said circuit and, after a period of operation, - isolating the tank 1 by means of valves 16, 17 placed upstream and downstream thereof, - moving the magnets 10 away from the tank 1 until it disappears effects of the magnetic field on the iron particles agglutinated against the internal partition 6, extract the vessel 1 the particles released from the magnetic attraction.

  In the stationary operating phase (that is to say when the fluid passes through the tank 1 in continuous mode), the fluid enters the upper part of the tank 1 in a horizontal direction tangential to the wall 4. The fluid still occupies approximately the same position, which defines a sequential vortex alternating a fluid flow band and a "dry" intermediate band. The fluid band, not very thick in its central part, is very thin at the edge, which further favors the magnetic attraction. The particles are deposited preferentially at the edge of the flow band and accumulate on the dry band where they can not be torn off by the flowing fluid.

  The residence time of the fluid in the vicinity of the magnetized bars 10 is increased by the vertical wrinkles 11 projecting into the internal volume of the vessel 1.

  The sludge separated by centrifugal effect is collected in the curved bottom 2 of the vessel 1.

  When it is desired to extract the particles and the sludge collected on the wall 4 and in the bottom 2 of the tank 1, the valves 16 and 17 are closed upstream and downstream of the device 100, the magnetic bars 10 are withdrawn from the recesses 9 Then the lid 3 is opened. The particles which are discharged towards the low valve 15 are driven by simple jet of water.

  If opening the vessel 1 before removing the magnets 10 (which does not present any drawback in the process according to the invention), it is possible to observe very clearly the result obtained by the flow in the form of sequential vortex: we see that clusters of particles are agglutinated along the lines 11 surrounding the magnets 10, at regular intervals of a few centimeters. The particles are deposited at the margin of the liquid band swirling along the wall at each passage in front of the magnets 10, accumulating on the dry intermediate band. 30

Claims (2)

11 CLAIMS   A device for removing particles suspended in a fluid transported in a circuit, comprising a cylindrical vessel (1) having a bottom (2), an upper wall (3) and a side wall (4). ) having an external partition (5) and an internal partition (6), said tank being connected to said circuit by an inlet duct (7) and an outlet duct (8), characterized in that said external wall of said wall lateral comprises at least one recess (9) in which is vertically housed at least one magnetic bar (10).   2- Device according to claim 1, characterized in that the outer wall (5) of the side wall (4) comprises two recesses (9) placed on either side of the tank (1), in each of which is housed a magnetic bar (10).   3- Device according to claim 1 or 2, characterized in that said at least one magnetic bar has a length at least equal to the height between the inlet duct (7) and the outlet duct (8).   4- Device according to one of the preceding claims, characterized in that the inlet duct (7) opens into the upper part of the vessel (1) in a substantially horizontal direction tangential to the wall (4).   5- Device according to one of the preceding claims, characterized in that the outlet duct (8) opens in the lower part of the vessel (1) in a substantially horizontal direction tangential to the wall (4).   6. Device according to one of the preceding claims, characterized in that the inlet duct and the outlet duct are arranged relative to each other so that their axis is in the extension of the same helical curve. .   7- Device according to one of the preceding claims, characterized in that said at least one recess has a depth greater than the thickness of the wall (4) so that the internal partition (6) has at least one vertical wrinkle ( 11) protruding into the internal volume of the vessel (1).   8- Device according to one of the preceding claims, characterized in that said at least one magnetic bar is a removable bar held in place in said at least one recess by a means (12) for movable attachment.   9- Device according to the preceding claim, characterized in that said at least one magnetic bar is mounted on an articulated support attached to the vessel (1), adapted to maintain said bar in its recess or at a distance therefrom.   10- Device according to any one of the preceding claims, characterized in that it further comprises a filter system (13) sludge and particles indifferent to the magnetic field, placed in the lower part of the tank (1).   11- Device according to one of the preceding claims, characterized in that the bottom (2) of the vessel (1) has a convex shape promoting the collection of sludge and particles 15 indifferent to the magnetic field.   12- Device according to one of the preceding claims, characterized in that the vessel (1) is equipped with an upper water intake pipe (14), a vent and a gas vent valve. low evacuation (15).   13- Device according to one of the preceding claims, characterized in that the upper wall (3) of the vessel is a movable cover adapted to be sealingly attached to the side wall (4).   14- Device according to one of the preceding claims, characterized in that the vessel (1) is made of non-magnetic materials.   15- A method of removing particles suspended in a fluid transported in a circuit, characterized in that it essentially comprises the steps of: - passing said fluid through a device according to one of claims 1 to 14, whose inlet duct (7) and the outlet duct (8) are connected to said circuit and, after a period of operation, - isolating the tank (1) by means of upstream valves (16) and downstream (17) thereof, - away said at least one magnet from the tank (1) until disappearance of the effects of the magnetic field on the iron particles agglutinated against the internal partition (6) in the vicinity of said at least one magnet, - extracting from the tank (1) the particles released from the magnetic attraction. 10 30 35   16- Method according to the preceding claim characterized in that the fluid enters the upper part of the vessel (1) in a substantially horizontal direction tangential to the wall.   17- A method according to claim 15 or 16 characterized in that the fluid is evacuated by the lower part of the vessel (1) in a substantially horizontal direction tangential to the wall.   18- A method according to one of claims 15 to 17 characterized in that the fluid flows into the vessel (1) in a substantially helical path against the inner wall (6).   19. A process according to claim 18, characterized in that the inflow rate of the fluid into the vessel (1) is adjusted so that a narrower fluid band is formed than the pitch of the helical path.   20- A method according to claim 18 or 19 characterized in that the residence time of the fluid in the vicinity of said at least one magnetic bar is increased by a vertical wrinkle (11) projecting into the internal volume of the vessel (1) at neighborhood of said at least one magnet.   21- Method according to one of claims 15 to 20 characterized in that sludge and particles indifferent to the magnetic field are further collected in the lower part of the tank (1).   22- Method according to the preceding claim characterized in that all the particles and sludge are entrained out of the tank (1) by a flow of water admitted into said tank through the upper pipe (14) and flowing through the valve low exhaust (15).