Straight fin tube with bended fins condensing heat exchanger

A forced convection fin tube condensing heat exchanger for supplying heat, comprising:

• a shell;
• a burner disposed at an upper portion of the shell, the burner being fluidly connected to an air/gas inlet;
• a plurality of fin tubes disposed in the shell, each of the plurality of fin tubes includes a multitude of fins disposed along a tube, each of the multitude of fins having two opposing edge portions bent at 90° relative to a body portion of the respective fin to generate a multitude of bent portions, the bent portions being aligned to generate two bending lines, the fin tubes being arranged tightly with the respective bent portions of the fins on adjacent fin tubes directly butting against one another and the plurality of fin tubes being disposed coaxially about the burner;
• a water inlet disposed outside the shell;
• a water outlet disposed outside the shell;
• a flue outlet disposed outside the shell;
• a flue channel defined by the shell and a row of fin tubes below the burner, wherein combustion flue gasses flow from the flue channel to a flue outlet;
• a front water manifold disposed at a first end of the plurality of fin tubes;
• a rear water manifold at a second end of the plurality of fin tubes;
• and
• a plurality of water baffles disposed inside the rear water manifold, the plurality of water baffles being configured to divide the manifold into a water inlet area and a water outlet area, wherein a flow of water enters a first portion of the plurality of fin tubes through the water inlet area, then the flow of water flows through the front water manifold, and then the flow of water flows to the water outlet area on the rear water manifold through a second portion of the plurality of fin tubes.