Abstract: A heat exchanger having a drainage member (1) mounted on an open end (322) of a heat-transfer tube (32), wherein the drainage member (1) contains a flow guide portion (11) including an insertion portion (11a) configured to be inserted into the heat-transfer tube (32) from the open end (322), and a projecting portion (11b) projecting toward an outside of the heat-transfer tube (32) from the open end (322) and extending downward.

Abstract: A turbulence member is made of a flat plate member configured to be inserted into a heat-transfer tube having a substantially elliptical cross-sectional shape. The flat plate member is a generate turbulence in a fluid flowing inside the heat-transfer tube by a plurality of projected pieces projected on both front and back surfaces. A rotation preventing piece configured to prevent rotation of the flat plate member inside the heat-transfer tube is provided in at least one of both side edges along the flow passage direction in the flat plate member. The rotation preventing piece is provided at a predetermined angle to the flat plate member so that a forefront comes into contact with a tube wall inner circumferential surface of the heat-transfer tube. A space through which the fluid can circulate is formed between the rotation preventing piece and the tube wall inner circumferential surface.

Abstract: An exhaust duct has a riser duct section which is connected to an exhaust port having such an inlet port at a lower portion of the riser duct section as is connected to an exhaust port for the combustion gas. The riser duct section extends upward along an external surface of the combustion box. A horizontal direction perpendicular to the front-to-back direction is defined as a lateral direction, then the riser duct section is formed into a flat shape having a smaller dimension in the front-to-back direction than the dimension in the lateral direction. Fluctuations in width between front-side and back-side plate parts of the riser duct section are devised to be restrained, and increase in size can be avoided. The riser duct section has a rail inside the riser duct section, the rail being elongated in the vertical direction and connecting together the front-side and the back-side plate parts.

Abstract: A method of premixing apparatus for missing fuel gas with air to supply thus obtained air-fuel mixture, through a fan to a burner, includes at a time of changing over to a small-capacity state in which a first ventilation resistance in an air supply passage is increased and also in which a second ventilation resistance in a gas supply passage is increased, rotating a butterfly valve down to a closing side stop angle; and at a time of changing over to a large-capacity state in which the first ventilation resistance in the air supply passage is decreased and also in which the second ventilation resistance in the gas supply passage is decreased, rotating the butterfly valve up to an open-side stop angle.

Abstract: Provided is a safety valve that can be satisfactorily closed. A safety valve includes a first valve port (13) and a first valve body (4) that are provided in a gas flow channel. The safety valve further includes an attracting part (3) that attracts the first valve body (4) by magnetic force. The safety valve further includes an electric drive mechanism (2) that moves the attracting part (3). The safety valve further includes a second valve port (14) and a second valve body (34) that are provided upstream of the first valve port (13). The second valve body (34) is provided on the attracting part.

Abstract: A combustion apparatus having: an upstream-side air supply chamber and a downstream-side mixing passage, both being respectively interposed between a fan and a burner; and a zero governor which is interposed in a gas supply passage and which adjusts a secondary gas pressure to a pressure equivalent to an internal pressure in the air supply chamber, thereby enabling to maximize a turndown ratio to the extent possible. The combustion apparatus has: first and second, totally two, mixing passages; a first gas outlet which is in communication with a narrowed part of the first mixing passage; a second gas outlet which is in communication with a narrowed part of the second mixing passage; a first air valve which varies an opening degree of an air inlet of the first mixing passage; a second air valve which varies an opening degree of an air inlet of the second mixing passage; and a gas valve.

Abstract: An indoor installation type combustion apparatus includes an upper surface of the exterior case has formed therein: a cylindrical exhaust connection port which is in communication with an exhaust duct and which is connectable to an exhaust pipe; a first cylindrical air supply connection port which is connectable to an air supply pipe of double-pipe system containing therein the exhaust pipe and which encloses the exhaust connection port; and a second cylindrical air supply connection port which is connectable to an air supply pipe of twin-pipe system which is separate from, and independent of, the exhaust pipe, a low-cost apparatus is provided in which the air flowing in from whichever the first and the second air supply connection ports will be treated by one and the same supply-air filter. An air supply box which is in communication with both the first and the second air supply connection ports is disposed.

Abstract: A heat exchanger including a heat transfer fin (1) having a heat-transfer-tube insertion hole (10) through which a heat transfer tube (40) is inserted, and a brazing material holding portion (100) provided above the heat-transfer-tube insertion hole (10) to hold a brazing material (4), wherein when the heat transfer tube (40) is inserted through the heat-transfer-tube insertion hole (10), left and right non-contact portions (15), (16) where a circumferential edge of the heat-transfer-tube insertion hole (10) and an outer circumferential surface of the heat transfer tube (40) are not in contact with each other are separately formed on an upper circumferential edge of the heat-transfer-tube insertion hole (10), and a brazing material guiding portion (100) extending toward the outer circumferential surface of the heat transfer tube (40) is formed between the left and right non-contact portions (15), (16).

Abstract: A heat exchanger for hot water supply (21) is comprised of: a first heat exchanging unit (21) a that heats the water, which is supplied from a second communication section x1 to the hollow portions of hollow plates P1 to P5 and reaches a first communication section y, by a combustion exhaust gas that circulates through the gaps among the hollow plates P1 to P5; and a second heat exchanging unit (21b) that heats the water, which is supplied from the first communication section y to the hollow portions of the hollow plates P6 to P8 below the hollow plates P1 to P5 and reaches a third communication section x2, by a heat medium that circulates through the gaps among the hollow plates P6 to P8.

Abstract: A premixing apparatus in which a downstream end of a gas supply passage having interposed therein a flow control valve is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan. The premixing apparatus has: a butterfly valve as an air resistance changeover device for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on the upstream side of the gas suction section; and a gas resistance changeover device for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on the downstream side of the flow control valve. Wind noises at the time of closing the butterfly valve can be prevented.

Abstract: A combustion apparatus has a burner including a burner body and a combustion plate, as well as a combustion box. A combustion plate flange part projects outward beyond an inner rim of a body flange part and beyond an inner rim of a combustion box flange part. A packing has a portion interposed between the combustion plate flange part and the body flange part, and a portion interposed between the combustion box flange part and the body flange part outside an outer rim of the combustion plate flange part. A distribution plate having formed therein a multiplicity of distribution holes for introducing the air-fuel mixture toward an air-fuel mixture ejection part is provided with a distribution plate flange part so arranged as to come into direct contact with that portion of the combustion plate flange part which is positioned inside an inner rim of the packing.

Abstract: A combustion apparatus has a burner including a burner body and a combustion plate, as well as a combustion box. A combustion plate flange part projects outward beyond an inner rim of a body flange part and beyond an inner rim of a combustion box flange part. The combustion box has, on a perimeter of one end, the combustion box flange part, adapted to be connected to the body flange part enclosing an open surface of the burner body. The combustion plate is provided with an inside projection which is erected, by bending, toward the body flange part so as to face the inner rim of the packing such that, in a state in which the combustion box flange part is connected to the body flange part, the outside projection and the inside projection are in contact with the body flange part.

Abstract: [Problems to be Solved] An exhaust duct (4) for assembly into a combustion apparatus has: a burner (1) to eject air-fuel mixture downward; and a combustion box (3) disposed on a lower side of the burner (1). The exhaust duct includes: a riser duct section (42) elongated in a vertical direction and having, at a lower portion thereof, an inlet port (41) connected to an exhaust port (35) for combustion gas which is opened in a lower portion of the combustion box (3); and a flat horizontal duct section (43) bent at an upper end of the riser duct section (42) so as to be elongated forward. By restraining the resonance of an upper wall part (431) and a lower wall part (432) of the horizontal duct section (43), noises due to resonance sounds are reduced. [Solving Means] The natural frequencies in an upper wall part (431) and the lower wall part (432) of the horizontal duct section (43) are varied from each other.

Abstract: A forced air supply combustion apparatus sucks combustion air from an air supply port. An air filter for collecting foreign matters in the air is mounted on an air-supply-port-formed plate in an insertable and drawable manner. A filter frame is arranged to be brought into close contact with a peripheral part of the air supply port in a state of having mounted the air filter in position. The air-supply-port side edge parts are provided with retaining pieces to clamp a filter side frame part in the Z-axis direction against the side edge parts. A distance in the Z-axis direction between the air-supply-port side edge parts, and the retaining pieces is set larger than a dimension, in the Z-axis direction, of the filter side frame part, and is set smaller than a sum of the dimensions to be obtained by adding to said dimensions the projection height of the projections provided in a projecting manner.

Abstract: A premixing apparatus in which a downstream end of a gas supply passage is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan, is provided with: a butterfly valve driven by a stepping motor, for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on an upstream side of the gas suction section; a changeover valve for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on an upstream side of a flow control valve; and an interlocking mechanism which opens or closes the changeover valve in interlocking with the rotation of the butterfly valve and which maintains the changeover valve in a closed state until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined angle.

Abstract: A fin-tube type of heat exchanger has: a plurality of fins laminated to one another; a housing for containing therein the fins; and a heat transfer tube penetrating the fins in a fin-laminating direction and also penetrating side plates on both sides of the housing. A heat transfer tube through hole is formed in one-side side plate of the housing by a burred hole having a tubular flange part protruded into the housing. Each fin has a brazing material insertion hole adjacent to the heat transfer tube through hole. That portion of a brazing material which protrudes from the brazing material insertion hole of the outermost fin closest to the one-side side plate part toward the one-side side plate part gets molten. The tubular flange part has a cutout part formed, at a circumferential position facing the brazing material insertion hole, by partly cutting away the tubular flange part.

Abstract: A heat transfer fin (31) made of stainless steel-based metal for a heat exchanger, has a plurality of upper stage heat-transfer-tube insertion holes (611), a plurality of lower stage heat-transfer-tube insertion holes formed (612), upper end cut portions (651) formed between the adjacent upper stage heat-transfer-tube insertion holes (611), and lower end cut portions (652) formed between the adjacent lower stage heat-transfer-tube insertion holes (612), wherein the upper end cut portions (651) are formed so as to extend from a fin upper end portion (311) beyond lower ends of the upper stage heat-transfer-tube insertion holes (611) to positions in the vicinity of upper ends of the lower stage heat-transfer-tube insertion holes (612), and the lower end cut portions (652) are formed so as to extend from a fin lower end portion (312) to positions above the lower ends of the lower stage heat-transfer-tube insertion holes (612).

Abstract: Provided is an attachment structure for a water heater capable of easily and securely attaching the water heater to a wall surface without performing strict alignment, and capable of fine adjustment of an attachment position of the water heater even after the attachment. The attachment structure for the water heater includes a first metal fitting (1) having a wall surface attachment portion (11) configured to be attached to a wall surface (W), and a second metal fitting (2) having an instrument attachment portion (23) configured to be attached to a back surface of the instrument body (3). In the wall surface attachment portion 11, a support portion (12) configured to hang and support a weight of the water heater is extended in a direction separate from the wall surface (W).

Abstract: A combustion apparatus includes a burner having a sheet-metal combustion plate which covers an open surface of a burner body; and a combustion box having a connection flange part to be coupled to a body flange part enclosing the open surface of the burner body, and is equipped with a cooling means for cooling the combustion box, an arrangement is made that overheating of the burner body due to heat transmission from the combustion plate can be prevented, even without enhancing thermal insulation performance of a packing to be interposed between a combustion plate flange part and the body flange part. The connection flange part is kept in direct contact with the combustion plate flange part and, coupled to the body flange part. The packing is provided with: a combustion plate seal part to be pressed under pressure against the combustion plate flange part; and a combustion box seal.

Abstract: A turbulence generator includes a flat plate member (1) having a plurality of through holes (10a), (10b), and pairs of projecting pieces (11, 12) and (13, 14) projecting respectively from upstream-side edges and downstream-side edges of the through holes (10a), (10b), wherein the pairs of projecting pieces (11, 12) and (13, 14) project alternately to front and back surface sides of the flat plate member (1).