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Title:
DEVICE FOR REMOVING MICROSCOPIC FERROUS PARTICLES FROM LIQUIDS IN DUCTS FOR FAST RUNNING FLUIDS, IN PARTICULAR FUELS AND LUBRICANTS
Document Type and Number:
WIPO Patent Application WO/2001/043848
Kind Code:
A1
Abstract:
A device for removing ferrous particles, even of microscopic dimensions, from liquids under rapid transit within ducts, particularly fuels and lubricants, having the characteristic of a magnetizing chamber (9, 9') provided for their transit and defined by an interspace between a high-power magnet (10, 100) and a ferromagnetic body (11, 1, 106), such as to concatenate the irradiated magnetic flux between these parts and reduce its dispersion to the outside.

Inventors:
Facchinetti, Luigi (Piazza S. Giorgio, 30 Fiorano al Serio, I-24020, IT)
Application Number:
PCT/IT2000/000517
Publication Date:
June 21, 2001
Filing Date:
December 13, 2000
Export Citation:
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Assignee:
ESVIELL S.R.L. (Via 5 Martiri, 1 Vertova, I-24029, IT)
Facchinetti, Luigi (Piazza S. Giorgio, 30 Fiorano al Serio, I-24020, IT)
International Classes:
B03C1/12; B03C1/28; F02M27/04; F02M37/22; F01M11/03; F02B3/06; (IPC1-7): B01D35/06
Domestic Patent References:
Foreign References:
GB991477A
US4026805A
GB909168A
GB684052A
US4067810A
EP0083774A1
Attorney, Agent or Firm:
Luksch, Giorgio (Ing. A. Giambrocono & C. S.r.l. Via Rosolino Pilo, 19/B Milano, I-20129, IT)
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Claims:
CLAIMS
1. A device for removing ferrous particles, even of microscopic dimensions, from liquids under rapid transit within ducts, particularly fuels and lubricants, characterised by comprising a magnetizing chamber (9,9') provided for their transit, and defined by an interspace between a highpower magnet (10,100) and a ferromagnetic body (11,106), such as to concatenate the irradiated magnetic flux between these parts and reduce its dispersion to the outside.
2. A device as claimed in the preceding claim, characterised in that the magnetizing chamber (9,9') is enclosed by a container (12,107) in diamagnetic material.
3. A device as claimed in the preceding claims, characterised by a magnetizing chamber formed by a permanent magnet having the form of a central cylindrical body (10) about which a coaxial ferromagnetic tube (11) is present such as to define an annular interspace.
4. A device as claimed in the preceding claim, characterised by a ferromagnetic tube (11) provided internally with helical grooves (22), preferably of triangular crosssection, comparable to a multistart thread.
5. A device as claimed in the preceding claims, characterised by a structure composed of two terminal connection members (3A, 4A, 105) which include axial entry (5) and exit (6) conduits and which grip within their conical centering recesses (17,104) a central magnet (10,100) about which there is freely positioned a ferromagnetic tube (11,106) forming an annular fuel transit chamber (9,9') and housed within a diamagnetic tube (12, 107) fixed to the terminal connection members (3A, 4A, 105) by suitable usual clinching (13,109) of its regions (15,16), to lock these in the position in which they axially fix the central magnet.
Description:
DESCRIPTION DEVICE FOR REMOVING MICROSCOPIC FERROUS PARTICLES FROM LIQUIDS IN DUCTS FOR FAST RUNNING FLUIDS, IN PARTICULAR FUELS AND LUBRICANTS.

TECHNICAL FIELD This invention relates to a device for removing microscopic ferrous particles from liquids in fast transit.

BACKGROUND ART Many situations are known to exist in which liquids have to be made to transit quickly through pipes under pressure. This liquid movement is in most cases derived from the action of pumps.

All types of pumps possess mechanical members subjected to mutual sliding, i. e. to wear which results in the circulation, within the same pumped liquid, of metallic fragments removed from the sliding surfaces. As the material most used for engineering purposes in this sector is steel (because of its high mechanical resistance and low cost) ferrous microscopic particles are present in most pumped liquids. By way of example, reference can be made to the rolling-contact bearings for the supports of centrifugal pumps, to the mutual sliding of the teeth of gear pumps or rotary pumps, to the rectilinear sliding of high-pressure pump pistons, etc. The result is that most liquids under rapid transit within pipes transport, suspended in them, the said particles of steel: a very hard material which, as such, can cause serious damage to the downstream members served by this liquid. In this respect, these microscopic steel particles can become wedged between surfaces of

mutually engaging machine members, to progressively damage them.

Typical examples of this situation are represented by transit pipes for internal combustion engine fuels (petrol, diesel fuel), by engine lubrication circuits, and by the interior of road vehicle gear boxes. In the first example, steel filings suspended in fuels are extremely damaging in the case of injection-fed engines, as the injection pumps operate with running clearances of just a few thousandths of a millimetre and are consequently very sensitive to wear in terms of injection throughput and/or pressure. In the second example, the presence of said steel filings results in a reduction in the necessary slidability of the parts, resulting in seizure and pitting. No specific solutions are available to eliminate these filings from fuels; however with regard to lubricants, use is made of the action of a magnet, generally positioned on the inner surface of a bottom plug of the oil tank (or of the gearbox): by periodically unscrewing this plug, the filings which have adhered magnetically to it during operation can be removed. These filings, captured and retained by the magnet present on the plug, represent however only a part of those in circulation, so that said magnet, conceived as a simple surface radiating a magnetic field, is unable to remove ferrous particles when these transit at the high speed involved in the shaking movements of the lubricant in which they are incorporated.

In certain cases of complex forced lubrication machines,"magnetic filtering"with usual magnets is used; said usual magnets are however of a low efficiency, because of the high dispersion of their magnetic field and the scarcity of low vorticosity recesses in which the ferrous particles linked together in the typical

filiform appearance created by the lines of flux of the magnetic field can collect. An object of the present invention is to define a device for removing ferrous particles, even of microscopic dimensions, from liquids transiting rapidly through ducts or pipes, particularly from fuels and lubricants. A further object is to define a device, as above, which is of low cost. A further object is to define a device, as above, which can be easily replaced periodically. A further object is to define a device, as above, which is structured in such a manner as to concentrate the magnetic flux onto the liquid to be treated. A further object is to define a device, as above, which reduces magnetic flux dispersion to the outside to negligible values, in order to prevent interference with the correct operation of any electronic circuits present in the vicinity of said the device.

DISCLOSURE OF THE INVENTION These and further objects will be seen to have been attained on reading the following detailed description, illustrating a device for removing microscopic ferrous particles from liquids under rapid transit within ducts, particularly fuels and lubricants, having the characteristic of comprising a magnetizing chamber provided for their transit and defined by an interspace between a high-power magnet and a ferromagnetic body, such as to concatenate the irradiated magnetic flux between these parts and reduce its dispersion to the outside.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated, by way of non-limiting example, in

Figure 1, in which the device is shown sectioned on a radial half- plane as far as the axis of symmetry. The other half of the device is shown as its internal constituent parts by partially removing its more peripheral parts. The profile which the device of cylindrical shape would have if its outer part were complete is shown by a thin line. Figure 2 shows one end of a device analogous to that of Figure 1, but in a different constructional version.

BEST MODE FOR CARRYING OUT THE INVENTION As already stated, the device must form a portion of the pipe carrying the liquid to be treated; it must therefore be provided with connectors which enable it to be integrated into said pipe.

These connectors are to be considered as usual threaded connectors. However, if it is to be used on liquids circulating under low pressure (for example engine fuels) or which enable rubber hoses to be used, the device could be provided with two holed shanks 1,2, able to be joined to them by usual hose clips 3 and 4 (Figure 1). In all cases, the device is provided with a conduit 5 for liquid entry and a conduit 6 through which the liquid leaves. The path followed by the fuel is indicated by arrows 7. After flowing through the entry conduit 5, the liquid flows through a conceptually radial channel 8 opening into a longitudinally extending annular chamber 9. After travelling through this, the liquid flows centripetally into a conceptually radial channel, to return into an axial position within the exit conduit 6. The annular chamber 9 is defined internally by a central cylindrical body 10, consisting of a permanent magnet of

very high field intensity. The higher this field intensity, the better the performance offered by the device. The value of this intensity therefore depends both on the current technology of the permanent magnet sector, and on the cost of such magnets, which obviously significantly influences the final cost of the device.

As an example, values of about 10,000 Oersted are achievable using, for example Neodymium-Iron-Boron magnets. This magnetic cylindrical body, or magnet 10, is polarised in a longitudinal direction so that its two poles, North N and South S, are disposed for example as indicated in Figure 1. The outer region of said annular chamber 9 is instead defined by the interior of a ferromagnetic tube 11 housed within a diamagnetic tube 12. This diamagnetic tube 12 is preferably constructed of brass, but for other reasons connected with the nature of the transiting liquid it may be preferable to use a suitable stainless steel. This diamagnetic tube 12 also performs the function of fixing all the parts of the device together by being sealedly clinched at 13,14, into annular grooves 15,16 in respective members 3A, 4A with which the two holed shanks 1 and 2 are integral. Rubber seal gaskets (not shown) could be housed in said grooves 15. The interior of said members is provided with suitably conical recesses 17, or 18, to be brought into gripping contact with the respective end of the magnet 10, which is itself made similarly conical to facilitate its centered location (self-centering) during assembly. The clinching 13 and 14 therefore stabilize this positioning. The previously mounted ferromagnetic tube 11 is also stabilized in position. It should be noted that said stabilization is achieved neither by clamping nor by interference

preloads; in fact the ferromagnetic tube 11 can preserve both an axial clearance 19 and a radial clearance 20 from its containing diamagnetic tube 12, which in this respect is locked against one side of the interior of said diamagnetic tube by the inevitable unbalance of the very strong magnetic field induced on it by the magnet 10 along the axis 21 of the substantially cylindrical parts of the device. The operation of the invention is now apparent from the structural configuration, defined as heretofore described. When any substance is positioned within a magnetic field, it is magnetised by induction, in that it manifests the presence of magnetic poles on its surface. Substances are generally classified as diamagnetic, paramagnetic and ferromagnetic. Diamagnetic substances are magnetised in an extremely weak manner, to the extent that they present their induced North pole in the region closest to the inducing North pole; i. e. the two North poles face each other (and hence repel each other, even if to a weak extent consequent on their weak magnetisation). In contrast, paramagnetic substances are magnetised to present their induced North pole in the region closest to the inducing South pole. Ferromagnetic substances are magnetised in the same manner, but with an intensity thousands of times greater to create the common attraction phenomena of magnets, known to all. Applying these scientific laws to the illustrated device, it will be apparent that the presence of the ferromagnetic tube 11, concentric about the magnetic cylindrical body 10, can concatinate onto itself all the flux radiated by said magnet 10. Consequently, there arises at one end of the tube 11 a polarity S'opposing the polarity N of the magnet, and at the

other end a polarity N'opposing the polarity S of the magnet.

Between the materials of these two parts 10 and 11 there thus develop very strong mutual attraction forces, which however remain powerful, because said parts 10 and 11, constrained mechanically in the described manner, are prevented from making mutual contact.

This means that the entire magnetic force possessed by the magnet 10 is concentrated within the interspace between said parts, which constitutes the annular chamber 9, without undergoing any dispersion. In this respect, external to the ferromagnetic tube 11 there is a casing in the form of the diamagnetic tube 12. As a result the South pole S'cannot expand to induce therein a complementary North pole, since it can induce only an analogous repulsive South pole S". Likewise, the North pole N'of the ferromagnetic tube 11 induces in proximity thereto in the diamagnetic tube 12 a North pole N". Consequently, when the liquid flows into the annular chamber 9, it is subjected to magnetic fields of immense force, not exertable by any of the magnets currently used to remove the"iron filings"from moving liquids. It follows that even the smallest ferrous particles undergo violent magnetic induction which develops forces in them able to urge them towards the opposite magnetic pole present in the various inner regions of the device. In Figure 1, the inner surface of the annular chamber 9 consists of helical grooves or projections 22, substantially similar to those of a multi-start thread. This solution is aimed at causing the treated liquid to undergo prolonged residence within the magnetic field present in said chamber, to enable all the ferromagnetic particles to come into contact with the inducing body. Prolongation of this liquid

residence is achieved by transforming its longitudinal (and hence brief) movement in transiting from the entry conduit 5 to the exit conduit 6, into a helical movement. With this helical movement, the fuel is in fact urged to travel along the greater length of the grooves. The closer the groove edges are to the concentric cylindrical surface of the magnet 10, the greater the extent of closure of the helical conduits, obliging the liquid to travel totally through them; the further these edges are from the said surface of the magnet 10, the more the liquid is enabled to flow into the annular chamber with rectilinear movement. From a practical viewpoint, the liquid moves with partly helical turbulent movement, which enables the ferromagnetic particles to locate themselves in the reduced-turbulence recesses and remain securely anchored within them. Figure 1 shows fuel being fed into the annular chamber 9 through an axial conduit 5 (or 6, the device being symmetrical) opening into two or four radial channels or holes 8: this solution is to be considered mainly as a conceptual example. In fact, from a constructional viewpoint, it could be more convenient to implement said inflow in other ways: for example, by providing in the conical recess 17 a number of diametrical end cuts to such a depth as to involve the axial conduits 5,6, to hence form radial channels having the same function as the channels 8. Another method could be that shown in Figure 2, in which the frusto-conical ends 102 of the magnet 100 are provided with oblique grooves 101, possibly made by flattening regions of the conical surface. Said ends lodge in respective recessed centering seats 104 present in a terminal connection member 105. In said Figure 2, the reference numeral 106 indicates

a ferromagnetic tube which closes the magnetic field about a chamber 9', similar to that achieved by the tube 11 of Figure 1.

The reference numeral 107 indicates a tube of diamagnetic material, comparable to the tube 12 of Figure 1. Figure 2 also shows a different method for joining together the constituent parts of the device, i. e. by end-flanging 109, sealed by an 0-ring 108 housed in an appropriate circumferential groove provided in the terminal member 105.