Bayonet heat exchanger having means for positioning bayonet tube in sheath tube

Claim 1

In a bayonet heat exchanger having means defining a first fluid manifold chamber, means defining a second fluid manifold chamber, means defining a heat exchanger chamber, a plurality of sheath tubes extending from said first fluid manifold chamber into said heat exchanger chamber, each of said sheath tubes having an open first end connected in fluid communication with said first manifold chamber and a closed distal end, a plurality of bayonet tubes, each of said bayonet tubes extending from said second fluid manifold chamber a substantial distance into a respective sheath tube through the open first end of the respective sheath tube, the distal end of each bayonet tube being open, the external dimensions of each bayonet tube being smaller than the corresponding internal dimensions of the respective sheath tube to provide an annular fluid flow passageway between said bayonet tube and the respective sheath tube, and means for maintaining the distal portion of each bayonet tube spaced from the transversely adjacent portion of the respective sheath tube while permitting the passage of fluid through the respective annular flow passageway; the improvement wherein said means for maintaining comprises spacer means secured to said transversely adjacent portion of the respective sheath tube and providing an opening through which the respective bayonet tube freely extends at least generally coaxially with the respective sheath tube, each said spacer means comprising a plurality of spacer elements, each said sheath tube having a plurality of longitudinal slots extending through the wall thereof corresponding in number and location to the number and location of said corresponding spacer elements, with the size and shape of each of said slots corresponding to the size and shape of a respective spacer element, each said spacer element being a solid bar element with the long dimension thereof at least generally parallel to the elongated axis of the respective sheath tube, each said bar element extending inwardly through a respective slot of a respective sheath tube with said bar element fixedly secured to the wall of the respective sheath tube to form a fluid tight joint therebetween and having at least the innermost side surface of the bar element diverging from the respective bayonet tube in the direction of said first fluid manifold chamber.