Shell and tube heat exchangers

A heat exchanger comprising:

• an inlet tubesheet and an outlet tubesheet;
• an elongated longitudinal shell assembly defining a first shell-side space and a longitudinal axis;
• the longitudinal shell assembly comprising opposing first and second ends, a circumferential sidewall extending between the first and second ends, a tube-side fluid inlet nozzle fluidly coupled to the inlet tubesheet, and a shell-side fluid outlet nozzle fluidly coupled to the circumferential sidewall;
• an elongated transverse shell assembly fluidly coupled to the first end of the longitudinal shell, the transverse shell assembly defining a second shell-side space and a transverse axis oriented perpendicularly to the longitudinal axis of the longitudinal shell, the second shell-side space being in direct fluid communication with the first shell-side space;
• the transverse shell assembly comprising opposing first and second ends, a circumferential sidewall extending between the first and second ends, a tube-side fluid outlet nozzle fluidly coupled to the outlet tubesheet, and a shell-side fluid inlet nozzle;
• a J-shaped tube bundle extending through the first and second shell-side spaces between the inlet and outlet tubesheets, the tube bundle comprising a plurality of tubes each having a first end fluidly coupled to the inlet tubesheet in the first shell-side space of the longitudinal shell and a second end fluidly coupled to the outlet tubesheet in the second shell-side space of the transverse shell;
• a tube-side fluid flowing through the tube bundle and a shell-side fluid flowing through the longitudinal and transverse shell assemblies;
• wherein the first and second tube-sheets are oriented non-parallel to each other;
• wherein the tubes each include a straight short section disposed in the transverse shell and fluidly coupled to the second tubesheet, a straight long section disposed in the longitudinal shell and fluidly coupled to the first tubesheet, and a radiused tube bend therebetween;
• wherein the transverse shell includes a tubeless space defining an auxiliary shell-side flow plenum at a first end portion of the transverse shell opposite a second end portion of the transverse shell attached to the second tubesheet, and a shell-side inlet nozzle on the transverse shell is coupled to the first end portion and arranged to introduce a shell-side fluid directly into the auxiliary flow plenum such that the shell-side fluid expands and undergoes a reduction in velocity before impinging the tubes in the transverse shell;
• a shell-side fluid inlet head sealably joined to the first end portion of the transverse shell and a tube-side fluid outlet head sealably joined to the second tubesheet in the transverse shell;
• wherein the longitudinal shell includes a shell-side outlet nozzle oriented perpendicularly to the shell-side inlet nozzle;
• wherein the shell-side inlet nozzle is configured to direct the shell-side fluid towards the radiused tube bend of each tube;
• and
• wherein the shell-side fluid auxiliary flow plenum in the transverse shell has an axial length DV measured along the transverse axis which extends from a terminal end of the shell-side fluid inlet head to a nearest point on the transverse shell where the longitudinal shell is attached to the transverse shell, the axial length DV being at least one quarter of a total axial length of the transverse shell measured along the transverse axis between the terminal end of the shell-side fluid inlet head to a second terminal end of the tube-side fluid outlet head to provide space for expanding the inlet shell-side fluid.