Pump/heat exchanger

Pump/heat exchanger assembly having tubes with double walls, inner and outer respectively, the outer wall being provided with inner longitudinal grooves, the said exchange occuring between a primary fluid circulating outside said tubes and a secondary fluid circulating inside said tubes, said assembly comprising:

• an outer cylindrical casing with a vertical axis, provided with a base, a lid and an inlet nozzle for the primary fluid arranged below said lid;
• an inner cylindrical collar inside said casing and coaxial therewith and integral at its upper end with said lid, said collar defining internally a central vertical channel and externally an annular space between said casing and said collar, said collar defining between itself and the base a passage which communicates between said central channel and said annular space;
• a plurality of said double-walled tubes arranged in said annular space, each of said tubes consisting of a plurality of inter-connected tube sections, said tube sections being in the form of convolutions having horizontal curved portions and elbowed portions, said tube sections being joined together at said elbowed portions.
• at least one leakproof annular chamber exterior to said annular space:
• a pump fixed to said lid and fitted with a rotor, said pump being located at the upper end of said central channel and adapted to draw in said primary fluid;
• means for detecting leaks in said tubes comprising means for injecting an inert gas, under a given pressure, into at least one of said annular chambers, and means for comparing the pressure of said gas in at least one of said chamber with a maximum and a minimum pressure;
• said tube sections being connected in said at least one chamber, the end of the outer wall of one section and the start of the outer wall of the next section opening into said chamber, and the end of the inner wall of one tube section being connected to the start of the inner wall of the next section, in leakproof manner, by an elbowed duct.