Abstract:
The invention relates to a fluid treatment assembly comprising a filter (4) which itself comprises filtering elements (5) and a cleaning device (12) for periodically cleaning each filtering element including a conduit (17) for the evacuation of the cleaning fluid filled with impurities resulting from the cleaning, the treament assembly further comprising a centrifuging device which itself comprises a rotary enclosure (37) connected to a fluid admission conduit (28). 
     According to the invention, the filtering elements (5) and the enclosure (37) are contained in a single casing (1A-1B), while the admission conduit (28) is directly connected (29-30) to the conduit (17) for evacuating the cleaning fluid. 
     The invention finds an application in the construction of a compact and reliable assembly.

Description:
TECHNICAL FIELD 
     A fluid treatment assembly is already known, which assembly comprises, on the one hand, a filter constituted of at least one filtering element, and on the other hand, a centrifuging device which device comprises a rotary centrifuging enclosure provided with an admission conduit. 
     In this known treatment assembly, the centrifuging treatment device is separated from the filter and is connected therewith via conduits external to each of said two treatment and filtering devices. 
     Such a treatment assembly is bulky, its cost price is high and it is subject to accidents, particularly where the external connection conduits are concerned. Moreover, the filter is generally a filter with disposable filtering elements. 
     BACKGROUND OF THE INVENTION 
     It is the object of the present invention to overcome said drawbacks by providing a filter that comprises a device for cleaning each filtering element including a rotary distributor driven by a motor and designed to periodically isolate one part of the filtering surface in order to enable the cleaning thereof with clean fluid flowing backwards through each filtering element and then into the centrifuging device, for purifying same, via an evacuation conduit. 
     Therefore according to the invention, the filtering element or element and the centrifuging enclosure are contained in a single casing, while the evacuation conduit for the cleaning fluid filled with impurities issues directly into the admission conduit of the rotary enclosure. 
     The advantageous following dispositions are also preferably adopted: 
     one end of one of the evacuation conduits is fitted in one end of the other of said two conduits, while the other end of the admission conduit is fixed on said single casing; 
     said other end of the admission conduit is fixed to said casing via a bolt which, at the same time, obturates said other end; 
     the centrifuging enclosure communicates with the inside of the casing via at least one outlet nozzle for the centrifuged fluid, which nozzle is oriented substantially perpendicularly to a radius passing through the axis of rotation of said centrifuging enclosure, in such a way that said centrifuging enclosure is driven in rotation by the reaction of the fluid coming out of said outlet nozzle or nozzles with respect to the fluid contained in the casing; 
     said evacuation conduit is provided in the rotaty distributor; 
     receiving chambers for receiving the fluid filtered by the filtering elements of the filter and the fluid treated by the centrifuging treatment device, are provided in said single casing, said chambers being separated one from the other by a fluidtight partition wall. 
     DISCLOSURE OF INVENTION 
     The invention offers the following main advantages: compactness of the treatment assembly, reliability of said assembly, and reduced production costs compared with the prior constructions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood and secondary characteristics and their advantages will emerge from the following description of one example of embodiment. 
     It is to be understood that the description and drawings are only given by way of indication and non-restrictively. 
     Reference will be made to the accompanying drawings, in which: 
     FIG. 1 is an axial section of a treatment assembly according to the invention, 
     FIG. 2 is a section along II--II of FIG. 1, and 
     FIG. 3 is a section along III--III of FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The fluid treatment assembly illustrated in the figures comprises a filter and a centrifuging treatment device, both of them being contained in a single casing 1 made up of two parts 1A, 1B, assembled by bolts. 
     The filter, which is contained in part 1A of the casing, comprises: 
     two transversal end walls 2, 3 between which is provided a stack 4 of filtering elements 5, each one of which is shaped into a filtering disk 9, with two screens 6; 
     a central axis 7; 
     aligned bores 8, having the same diameter, and being coaxial to axis 7, each bore belonging to one of the filtering disks 9, in tight contact with the cylindrical external face 10 of a liner 11, which liner comprises a bore 15 co-axial to the axis 7; 
     a central fluid distributor 12, mounted for rotation about axis 7, in tight contact with a bore 13 provided in the intermediate wall 2, said wall being itself tightly assembled to pans 1A and 1B of the casing; 
     a U-section sector 14, provided in the fluid distributor 12, the periphery 16 of which bears tightly against the bore 15 of the liner 11, and which communicates with an evacuation conduit 17 provided in the fluid distributor 12, coaxial to axis 7; 
     a driving fork 18, situated at the axial end of the fluid distributor 12 opposite the intermediate wall 2; 
     a receiving chamber for receiving the filtered fluid 19, which chamber is provided inside the part 1A of the casing, contains the stack 4 of filtering elements 5 and is equipped with a connector 20 for the evacuation of the filtered fluid; 
     an admission chamber 21 for admitting the polluted fluid to be filtered, said chamber being equipped with an admission connector 22 for admitting the fluid to be filtered; 
     a motor 23, in this particular example, a hydraulic motor, for driving the fluid distributor 12 in rotation, said motor being fixed on the part 1A of the casing and being equipped with a driving member 24 operationally coupled to the fork 18 for driving the fluid distributor 12 in rotation. 
     Each filtering element 5 comprises a plurality, counting twelve in the embodiment illustrated in FIG. 2, of angular sectors 41 which, through orifices 25 provided in the liner 11 and in the bores 8, are adapted, successively, to create a communication between the inside space 27 defined by the parts of the two screens 6 of the sector considered, and a conduit 26 which is provided in sector 14 of the fluid distributor 12 and which issues into the evacuation conduit 17, which latter is a blind conduit at the end of the fluid distributor 12 facing the wall 2. 
     The centrifuging treatment device is contained in part 1B of the casing and comprises: 
     a central admission conduit 28 for admitting the fluid to be centrifuged, of which one end 29 is constituted by an endpiece fitted in the open (non-blind) end 30 of the evacuation conduit 17, while the other end 31 is constituted by a female thread for fixing in an obturating bolt 32; the bolt 32 itself constitutes the end of a plug 33 screwed 34 into a transversal end plate 35 which defines, in part 1B of the casing, a chamber 36 for receiving the centrifuged fluid, which chamber is tightly separated from the chamber 19 receiving the filtered fluid, by the intermediate wall 2; 
     a centrifuging enclosure 37 is mounted for rotating, via rings forming smooth bearings, about axis 7, which axis 7 is also the axis of the admission conduit 28 and of its external face 28A, said conduit therefore forming also a rotary shaft for the centrifuging enclosure 37; 
     orifices 38 creating a communication between the admission conduit 28 and the inside 39 of the enclosure 37. 
     A transversal bottom 40, which is perpendicular to the axis 7, defines the part of the centrifuging enclosure 37 which is placed in facing relationship to the transversal wall 2. Said centrifuging enclosure 37 is totally isolated from the receiving chamber 36 receiving the centrifuged fluid except for the communication created by two outlet nozzles 43, which are substantially diametrically opposite, and whose outlet orifices are directed so as to be substantially perpendicular to a diameter passing through the axis 7, and in two opposite directions. 
     The treatment assembly works as explained hereinbelow. 
     The fluid to be treated, which is admitted into the admission chamber fills in the inner spaces 27 of all the sectors of the various filtering elements 5, with the exception of the space inside the sector 41 of each filtering element which is temporarily isolated from the other sectors 41 by the U-section sector 14 which is, itself, in communication with the conduit 26. 
     This fluid to be filtered, which is contained in said spaces 27, flows through the screens 6 of said sectors, depositing on the inner faces thereof, the impurities that it contains, and being received when cleared of its impurities, into the receiving chamber 19 receiving the filtered fluid which is ready to be used again. 
     Conversely, as regards the sectors 41 of the various filtering elements which only communicate with the conduit 17, the pressure of the already filtered fluid which is contained in the chamber 19, causes past of said fluid to flow through the corresponding parts of the filtering screens 6, this enabling the impurities which have deposited on the inner faces of the screens to be periodically detached therefrom and to be driven into the evacuation conduit 17. The function of the motor 23 is to drive stepwise, sector 41 by sector 41, the distributor 12 in rotation so as to ensure that each angular sector 41 of the various filtering elements is periodically placed in communication with the evacuation conduit 17. 
     Said fluid filled with impurities is conveyed directly via the evacuation conduit 17 and the admission conduit 28 towards the centrifuging enclosure 37, where it is received therein 39 and where, by centrifuging, it is cleared of its impurities. The purified fluid is then evacuated out of the enclosure 37 through the nozzles 43 and is received into the chamber 36 wherefrom it is released towards an application unit, via an outlet connector 44 provided in part 1B of the casing. 
     It should be observed that the rotation of the centrifuging enclosure 37 is induced by the effect of reaction, with respect to the fluid contained in the enclosure 37, of the fluid escaping from the inside 39 of the enclosure 37 through the conduits 42 of the nozzles 43. Said reaction effect is sufficient to drive the centrifuging enclosure in rotation at a rotation speed--of the order of 6000 rpms--at which the centrifuging is effectively performed. As a reminder, the speed of rotation reached by the motor 23 is around 2 to 3 rpms. 
     The advantage of the described embodiment resides in the compactness and light weight of the assembly; in the elimination of any leaks from the external connections between filter and centrifuging device, due to the elimination of said external connections; in the elimination of any risks of the external conduits breaking up, as these conduits have also been eliminated; and finally, in the obtained reduction of the assembly manufacturing costs. 
     It is understood that the invention is not limited to the embodiment of filters equipped with disks or pads as filtering elements, but also covers the case of any other filters such as, for example, those having cylindrical screens. The motor 23, which is advantageously a hydraulic type motor, may also, as a variant, be of another type, such as electric. Finally, at least one nozzle 43 should be provided, and preferably an even number of diametrically opposite nozzles. 
     The invention finds an application in the treatment of lubricating oils for &#34;Diesel&#34; type engines, or even in the purification of certain fuels used by said engines. 
     The invention is not limited to the described embodiment, and on the contrary covers any variants that can be made thereto without departing from its scope or its spirit.