Heat exchanger having adjustable baffles

A shell-and-tube heat exchanger comprising a tube assembly made up of a number of tubes through which a first medium flows in use and around and between which a second medium flows in use to accept heat from, or transfer heat to, the first medium flowing in the tubes, and a series of spaced baffles carried on rods extending through the heat exchanger, the positions of the baffles on the rods being adjustable to suit different media flow rates, being arranged transversely to the tubes to constrain the second medium to follow a tortuous path which extends back and forth across the tubes and being completely separate from the tubes, so permitting them to be replaced or adjusted without the necessity of disassembling the tube assembly, wherein the tubes pass transversely through a plurality of fins in the shell, the second medium flowing in use on its tortuous path transversely to the tubes between the fins and wherein the fins do not extend completely across the interior of the shell but have portions missing from their peripheries which correspond in shape to the baffles.