Abstract: A heat exchanger for heat exchange between a working fluid and a coolant having an inner casing, an outer casing, and an annular space formed therebetween. A tube bundle including at least one tube formed into a helical coil is located within the annular space. End plates are removably secured and sealed to the ends of the outer casing. Bulkhead fittings are mounted in openings of the end plates to seal the tube ends which pass through the end plates. The bulkhead fittings are sized to permit the end plates to be moved off of the bulkhead fittings in a direction away from the helical coil. The tube bundle may also include a separating plate extending longitudinally between the coils of two tubes within the tube bundle creating two separate passages through which coolant may flow. External tubes may be connected at the tube ends, outside of the outer casing and the end plates, such that the working fluid flows in a parallel single-pass flow or a series double-pass flow through the annular space.

Abstract: A heat exchanger is provided, including a tubular shell having an opening in one end thereof, an open-topped, side-slotted shroud mounted inside the shell, a bundle of tubes extending through the opening into the shroud, means for circulating a hot fluid through the bundle of tubes,means for charging a heat-exchange fluid to the space between the shell and the shroud for flow through slots into the shroud and into indirect heat exchange contact with the bundle of tubes for cooling the hot fluid, andmeans for removing heated exchange fluid from the top of said shell.