Filtering device incorporating a circulation loop

1. Device for tangential filtering of a fluid to separated into a filtrate and a retentate, said device comprising within a housing ( 2 ):

at least one inlet (E) for the fluid to be treated,

at least one outlet (S) for evacuation of the retentate,

a series of filtering elements ( 3 ) of tubular shape extending parallel to each other and sealingly penetrating a positioning plate ( 4 ) at each of their ends, the filtering elements ( 3 ) each comprising at least one circulation channel ( 3 1 ) for the fluid to be treated and providing filtering of said fluid, so as to obtain egress of the filtrate at the peripheral surface of the filtering elements, to be recovered in a collection volume ( 6 ) located between the positioning plates ( 4 ) and the housing ( 2 ),

at least one outlet ( 7 ) for the filtrate communicating with the filtrate collection volume ( 6 ),

a first communicating chamber ( 11 ) into which open one end of the filtering elements and which provides communication between the outgoing circuit and the return circuit of at least one circulation loop for the fluid to be treated,

a separating part ( 15 ) mounted in the first communicating chamber ( 11 ), in sealed contact with the neighboring positioning plate ( 4 ), to divide said chamber into a first sub-chamber (V 1 ) and a second (V 2 ) sub-chamber delimited externally and internally by the separating part and communicating with the outgoing and return circuits, the separating part dividing the filtering elements ( 3 ) into a first series (s 1 ) opposite the first sub-chamber placed in the outgoing circuit of the fluid to be treated and a second series (s 2 ) opposite the second sub-chamber placed in the return circuit of the fluid to be treated,

a communication passage ( 24 ) between the first sub-chamber (V 1 ) and the second sub-chamber (V 2 ),

a turbine ( 23 ) of a circulating pump disposed within one of the first and second sub-chambers, the turbine being fitted with a driving shaft ( 25 ) extending outside the first chamber ( 11 ) for connection to a driving motor ( 26 ), and

a closure housing ( 13 ) sealed to a neighboring positioning plate ( 4 ), delimiting the first communicating chamber ( 11 ) and sealingly traversed by the driving shaft ( 25 ) of the turbine ( 23 ).

2. Arrangement as described in claim 1 , wherein the separating part ( 15 ) is mounted in such a way that the first and second series (s 1 , s 2 ) of filtering elements ( 3 ) have an approximately equal number of filtering elements ( 3 ).

3. Arrangement as described in claim 1 , wherein the driving shaft ( 25 ) is mounted in the alignment of the axis of the collar ( 9 ) and that the driving motor ( 26 ) is supported by the closure housing ( 13 ).

4. Arrangement as described in claim 1 , further comprising a second communicating chamber ( 12 ) delimited between a sealing cap ( 14 ) and the positioning plate which does not delimit the first communicating chamber ( 11 ), said second chamber ( 12 ) providing fluid feed to the outgoing circuit and recovery of the fluid to be treated after it has circulated in the return circuit.

5. Arrangement as described in claim 4 , wherein the sealing cap ( 14 ) which delimits the second communicating chamber ( 12 ), is fitted:

with inlet (E) for the fluid to be treated,

with outlet (S) for evacuation of the retentate,

and with an outlet ( 7 ) for the filtrate communicating with the filtrate collection volume ( 6 ) by means of orifices in the neighboring positioning plate ( 4 ) and in the sealing cap ( 14 ).

6. Arrangement as described in claim 1 , wherein the positioning plates ( 4 ) are connected between themselves by means of a collar ( 9 ) delimiting the filtrate collection volume ( 6 ).

7. Arrangement as described in claim 5 , wherein the sealing cap ( 14 ), the closure housing ( 13 ), the positioning plates ( 4 ), the separating part ( 15 ) and the collar ( 9 ) are fabricated of plastic.

8. Arrangement as described in claim 1 , wherein the first and second sub-chambers are concentric, and the turbine is mounted in an inner sub-chamber.