A water heater includes an inner water tube coil and an outer water tube coil separated by a drum baffle. The inner and outer coils extend above a top edge of the drum baffle by at least a full turn of each coil. A flue gas bypass path is defined between a top edge of the drum baffle and a top insulation layer above the inner and outer coils. Flue gases flow radially though the inner coil, up along the drum baffle, through the flue gas bypass path, and downwardly over the outer coil to heat water flowing through the inner and outer coils. The water flows into the outer coil at the bottom of the coil, winds upwardly through the outer coil in countercurrent flow with respect to the flue gases, then down through the inner coil.

A flue baffle for a water heater comprises a plurality of holes along a length of the baffle and a plurality of bent blades along the length of the baffle, where each hole of the plurality of holes is adjacent to a bent blade of the plurality of bent blades. The holes are configured to permit flue gas to pass through the holes. The bent blades can have an alternating pattern where a first bent blade extends from one side of the baffle and the next bent blade extends from an opposite side of the baffle. A press tool for forming the baffle comprises a piercing tool for forming the plurality of holes and a lance and fold die for forming the bent blades.

A combustion cell (1) for a heating system comprising: a fan unit (2), configured to supply a flow of premixed air-gas required for the combustion, a lid (3); a burner, (5) comprising a central perforated zone (501) and a peripheral zone (502) free of holes; a distributor (6), comprising a peripheral part provided with apertures (601) and positioned upstream of the burner (5) for feeding the flow of premixed air-gas to the burner (5), with its peripheral part facing towards the peripheral zone (502) of the burner (5); a flange (7) configured to connect the lid (3) to the burner (5); a coil (8) for exchanging heat, wherein the flange (7) has a receiving surface (701) which receives a first spiral (801) of the coil (8) to exchange heat in direct contact with the flange (7).

Some embodiments provide a gas device, the gas device includes a frame and a baffle; the baffle is arranged in the frame, the baffle includes an air guide portion and a heat insulation portion, the air guide portion and the frame are enclosed to form a first air guide channel, and the air guide portion is provided with a first air outlet, the first air outlet communicates with the first air guide channel, and faces the heat insulation portion. In the gas device provided by the present disclosure, a baffle is arranged on the inner side of the gas device, and the baffle can reduce the heat transferred from the inside of the gas device to the gas device, reducing the temperature of the gas device, and reduce the impact of the high temperature generated by the burner on the sheet metal components such as the gas device.

The present disclosure discloses a gas mixing device and a gas water heating device. In which, a gas mixing device, comprises: a shell provided with a fuel gas channel for inputting fuel gas, an air channel for inputting air and a gas mixing channel, the fuel gas channel being provided with a first cut-off portion capable of changing a flow area, and the air channel being provided with a second cut-off portion capable of changing a flow area; a moving part movable in the shell, the moving part simultaneously changing the flow areas of the first cut-off portion and the second cut-off portions by moving. The gas mixing device and the gas water heating device can provide a higher regulation ratio, thereby solving the problem that the water temperature is too high in summer.

A water heater can include a baffle and a slab heat exchanger with at least two rows of heat exchanger tubes, each row comprising a plurality of heat exchanger tubes. At least one of the heat exchanger tubes comprises a tube and a plurality of fins on the exterior of the tube circumscribing the tube, wherein the outer edge of each fin of the plurality of fins is bent at least at the same three areas of each fin such that the bends form at least three flat or concave areas running along the length of the heat exchanger tube.

Embodiments include various water heaters. In one example, a water heater includes a burner, an exhaust vent, a corrugated baffle having a first slit having a first length and a second slit having a second length that is less than the first length, and a heat exchanger. The heat exchanger includes a first set of heat exchanger tubes arranged in a first row, and a second set of heat exchanger tubes arranged in a second row, the second set of heat exchanger tubes having a third tube having a first angled surface and a second angled surface, where the first angled surface and the second angled surface together form a fin. The third tube can be arranged such that the fin is disposed at least partially between the first curved outer surface and the second curved outer surface.

A boiler system having a generally cylindrical housing or shell includes a main or fire tube with a furnace or combustion chamber extending longitudinally near the bottom of the housing and a burner to accomplish combustion within the combustion chamber. The combustion chamber opens at its rear end to furnace tube sheet, and to a first set of tubes extending longitudinally of the boiler. The first set of tubes extends to and through the rear tube sheet of the boiler to a turnaround space, which transitions to a second set of tubes located above the combustion chamber and first set of tubes to generally span a length extending from the rear tube sheet of the boiler to the front tube sheet. The boiler system as disclosed has a reduced size while maintaining efficiency in steam and hot water applications.

A heat exchanger for heating a fluid flowing through a pipe using a combustion gas includes: a body including open upper and lower ends and having a space formed therein to allow the combustion gas to pass therethrough; a combustor formed in an upper portion of the space in which combustion of the combustion gas occurs; a heat exchange portion formed below the combustor and provided with a heat exchange pipe configured to heat an internal fluid by using the combustion gas; and a heat return pipe provided outside the space so as to be in contact with an outer surface of the body, wherein the combustor and the heat exchange portion may be unitarily formed, and the body in which the combustor is formed includes a concave portion protruding concavely inward so as to correspond to a shape of an outer circumferential surface of the heat return pipe.

The present subject matter relates to a smoke tube boiler including: a mix chamber, a heat exchanger, a firing rod assembly, a sealing means, and an air-cooled cooling means and a water-cooled cooling means.