High efficiency folded plate heat exchanger

A packaged folded plate heat exchanger unit comprising:

• at least two modular heat exchangers joined together in front-to-back relation, each heat exchanger module including a folded sheet of heat conductive material having opposed longitudinal edges and opposed side edges, the folds defining on the front and back of the sheet a plurality of parallel longitudinal ridges and parallel longitudinal channels between the ridges;
• a pair of flat, substantially rectangular flow plates located on the front and back ridges, respectively, the flow plates having opposed side edges spanning the side edges of the folded sheet and having opposed longitudinal edges that are closer together than the longitudinal edges of the sheet, thereby exposing longitudinally upper and lower portions of the sheet;
• a pair of opposed side plates sealingly attached at right angles to the side edges of the flow plates and longitudinally spanning the side edges of the sheet, the side plates having a depth in the front-to-back direction of the sheet which exceeds the distance between the flow plates so that each side plate projects a predetermined distance from the front flow plate;
• each flow plate being sealingly attached at its side edges to a respective side plate, each folded sheet being sealingly attached along its side edges to at least one of a respective side plate and a respective flow plate and the front longitudinal edges of the side plates of the first module being joined to the back longitudinal edges of the side plates of the second module, thereby defining a three dimensional plenum space between the first and second modules;
• means sealingly engaging the front flow plate of the first module, the side plate projections, and the back flow plate of the second module, for blanking off said upper exposed portions of the sheets from the lower exposed portion of the sheets except for flow through said channels on the first and second modules, thereby defining respective upper and lower flow plena between the first and second modules.

A packaged folded heat exchanger unit comprising:

• at least four modular heat exchangers joined together in front-to-back relation, each heat exchanger including a folded sheet of heat conductive material having opposed longitudinal edges and opposed side edges, the folds defining on the front and back of the sheet a plurality of parallel longitudinal ridges and parallel longitudinal channels between the ridges;
• a pair of flat, substantially rectangular flow plates located on the front and back ridges, respectively of each sheet, and having opposed side edges spanning the side edges of each respective sheet and having opposed longitudinal edges that are closer together than the longitudinal edges of each respective sheet, thereby exposing longitudinally upper and lower portions of the sheets;
• a pair of opposed side plates sealingly attached at right angles to the side edges of each flow plate and longitudinally spanning the side edges of each respective sheet;
• each flow plate being sealingly attached at its side edges to a respective side plate and each folded sheet being sealingly attached along its side edges to at least one of a respective side plate and a respective flow plate;
• a first plate sealingly engaging the front flow plate of the first module and the back flow plate of the second module, a second plate sealingly engaging the front flow plate of the second module and the back flow plate of a third module, and a third plate sealingly engaging the front flow plate of the third module and the back of the flow plate of the fourth module, thereby defining first, second, and third upper plena and first, second, and third lower plena between the front flow plate of the first module and the back flow plate of the second module, the front flow plate of the second module and the back flow plate of the third module and the front flow plate of the third module and the back flow plate of the fourth module, respectively;
• means for closing the longitudinal ends of the channels in each heat exchanger;
• first, second, and third upper baffle plates extending vertically from the respective means for closing the longitudinal ends of the channels of said, first, second, and third sheets, each of said baffles being of modular construction and nested together front-to-back to define a plurality of independent flow distribution chambers, each chamber fluidly connected to a respective one of said plena.