Heat exchanger with concentric tubes

1. An improved concentric tube heat exchanger, comprising: at least a cylindrical tube ( 1 ) for circulation of a product to be treated, provided with a flanged inlet ( 11 ) and a flanged outlet ( 12 ) of the product; a hollow body ( 2 ) internally of which an exchange service fluid circulates, the hollow body being arranged concentrically internally of the tube ( 1 ) and configured such as to define internally thereof compulsory pathways respective for an outward and a return run of the exchange service fluid and such as to have the inlet and the outlet of the exchange service fluid arranged at a same end of and in proximity of an end of the tube; a flanged inlet connector ( 3 ) for introducing the product into the tube ( 1 ), a flange ( 3 a ) of which the inlet connector ( 3 ) connects with an inlet flange ( 11 a ) of the inlet ( 11 ) of the tube; a flanged outlet connector ( 4 ) for extracting the product from the tube ( 1 ), a flange ( 4 a ) of the outlet connector ( 4 ) connects with a flange ( 12 a ) of the outlet ( 12 ) of the tube; an intermediate flange ( 5 ), said intermediate flange ( 5 ):

being solidly connected to the end of the hollow body provided with the inlet and the outlet for the exchange service fluid;

projecting from the tube ( 1 );

being, provided with a passage hole ( 5 c ) for the product to be treated and with an inlet mouth ( 5 a ) and an outlet mouth ( 5 b ) for the exchange service fluid, respectively connected to the outward and return pathway of the exchange service fluid; the passage hole ( 5 c ), inlet mouth ( 5 a ) and outlet mouth ( 5 b ) not being in reciprocal connection;

the passage ( 5 c ) for the product to be treated crossing the intermediate flange ( 5 ) in the axial direction of the tube ( 1 );

the flange of the inlet connector ( 3 ) and the inlet flange ( 11 a ) of the inlet ( 11 ) of the tube in combination embracing the intermediate flange ( 5 ) between them; or the flange ( 4 a ) of the outlet connector ( 4 ) and the flange ( 12 a ) of the outlet ( 12 ) of the tube in combination embracing the intermediate flange ( 5 ) between them.

2. The exchanger of claim 1 , wherein the intermediate flange ( 5 ) exhibits a central hub ( 6 ) subdivided into two zones, separate from one another and respectively connected to the outward and return pathway of the exchange service fluid; the central hub ( 6 ) is connected to an external crown ( 7 ) an internal diameter of which is equal to an internal diameter of the tube ( 1 ), by means of two spokes ( 7 a , 7 b ) internally of which the inlet mouth ( 5 a ) and the outlet mouth ( 5 b ) for the exchange service fluid are afforded; the passage hole ( 5 c ) is afforded in through-slots delimited by the central hub ( 6 ), the external crown ( 7 ) and the spokes ( 7 , 7 b ).

3. The exchanger of claim 2 , wherein at least an annular cavity is afforded on each of lateral surfaces of the external crown ( 7 ), which cavity is arranged in proximity of an internal diameter of the external crown ( 7 ) and is destined to house a seal ring ( 8 ); a radial thickness of the external crown ( 7 ) is kept to a minimum necessary for containing the annular cavity and ensuring mechanical resistance of the crown.

4. The exchanger of claim 2 , wherein at least two concentric annular cavities are afforded on each of lateral surfaces of the external crown ( 7 ), a first of which cavities is arranged in proximity of an internal diameter of the external crown ( 7 ), and a second of which is located at a radial distance from the first cavity which is twice a width of each cavity, each of which cavities is destined to house a seal ring ( 8 ); a radial thickness of the external crown ( 7 ) is kept to a minimum necessary for containing the annular cavities and ensuring mechanical resistance of the crown.

5. The exchanger of claim 2 , wherein: the central hub ( 6 ) is closed on an opposite side to a side facing towards inside the tube ( 1 ), by an ogive cover ( 10 ); external surfaces of the two spokes ( 7 a , 7 b ) that come into contact with a flow of the product to be treated being tapered and rounded.

6. The exchanger of claim 1 , wherein two reciprocally-parallel flat areas ( 55 , 56 ) are fashioned on a lateral surface of the intermediate flange and at the inlet mouth ( 5 a ) and the outlet mouth ( 5 b ).

7. The exchanger of claim 1 , wherein the flanges of the connectors connect with the flanges of the tube by means of through-bolts ( 9 ) which fasten the flanges together and which are arranged at corners of a polygon, wherein the intermediate flange ( 5 ) has a diameter of such dimensions as to be contained internally of an ideal perimeter of the polygon at corners of which the bolts ( 9 ) are located.

8. The exchanger of claim 1 , wherein the hollow body ( 2 ) is maintained in a concentric position internally of the tube ( 1 ) by means of tabs ( 60 ), solidly connected to an external wall of the hollow body and exhibiting a profile lacking in edges.