Multi-section heat exchanger means

In a multi-section heat exchanger unit for recovering heat values from a heated gas stream, said unit including:

• a. a first heat exchange section, said first heat exchange section comprising a first outer housing section having a heated gas inlet, a heated gas outlet and a plurality of heat exchange pipe means, said heat exchange pipe means being positioned through said first outer housing section and in fluid communication with a first heat exchange fluid inlet and a first heat exchange fluid outlet to provide heat exchange fluid flow through said heat exchange pipe means and said first heat exchange section, said heat exchange pipe means comprising pipes positioned in a plurality of substantially parallel rows, said rows being substantially perpendicular to a vertical axis of said unit with alternate rows being positioned so that the pipes in alternate rows are positioned substantially between the pipes in adjacent rows;
• b. a second heat exchange section comprising second outer housing section having a heated gas inlet and a heated gas outlet, said heated gas inlet of said second heat exchange section being in fluid communication with said heated gas outlet of said first heat exchange section, said second section including a plurality of heat exchange tube means, said tube means being positioned through said second outer housing section and in fluid communication with a second heat exchange fluid inlet and a second heat exchange fluid outlet to provide heat exchange fluid flow through said tube means and said second heat exchange section, said second heat exchange fluid outlet being in fluid communication with said first heat exchange fluid inlet of said first heat exchange section, said second outer housing section being shaped to enclose an internal cross-sectional area, which decreases between its heated gas inlet and its heated gas outlet so that said area is at a maximum at its inlet,
• the improvement comprising joining said pipes at their ends by means for directing said heat exchange fluid flow through said pipes so that said heat exchange fluid flows sequentially through a first pipe positioned in a first row, through a second pipe positioned in a second adjacent row, through a third pipe positioned in said first row in a repeating sequence through substantially all of said pipes in said first and second rows and then through a third row and a fourth row and subsequent rows in substantially the same repeating sequence so that said heat exchange fluid flows sequentially through substantially all of the pipes in said first heat transfer section to provide an improved first heat transfer section efficiency.

In a multi-section heat exchanger unit for recovering heat values from a heated gas stream, said unit including:

• a. a first heat exchange section, said first heat exchange section comprising a first outer housing section having a heated gas inlet, a heated gas outlet and a plurality of heat exchange pipe means, said heat exchange pipe means being positioned through said first outer housing section and in fluid communication with a first heat exchange fluid inlet and a first heat exchange fluid outlet to provide heat exchange fluid flow through said heat exchange pipe means and said first heat exchange section, said heat exchange pipe means comprising pipes positioned in a plurality of substantially parallel rows, said rows being substantially perpendicular to a vertical axis of said unit with alternate rows being positioned so that the pipes in alternate rows are positioned substantially between the pipes in adjacent rows;
• b. a second heat exchange section comprising a second outer housing section having a heated gas inlet and a heated gas outlet, said heated gas inlet of said second heat exchange section being in fluid communication with said heated gas outlet of said first heat exchange section, said second section including a plurality of heat exchange tube means, said tube means being positioned through said second outer housing section and in fluid communication with a second heat exchange fluid inlet and a second heat exchange fluid outlet to provide heat exchange fluid flow through said tube means and said second heat exchange section, said second heat exchange fluid outlet being in fluid communication with said first heat exchange fluid inlet of said first heat exchange section, said second outer housing section being shaped to enclose an internal cross-sectional area, which decreases between its heated gas inlet and its heated gas outlet so that said area is at a maximum at its inlet, at least one of said heat exchange section and said second heat exchange section including a removable door means, the improvement comprising first angular members positioned about said door and adapted to matingly join with second angular members secured to the periphery of an opening positioned in a side of said housing section and adapted to receive said door so that said door is readily positioned by mating said first and second angular members to sealingly position said door over said opening.