Abstract: An air blower and a combustion device including the air blower are provided. An air blower includes an impeller housed in a casing and rotating. The impeller includes multiple blades to form multiple inter-blade passages, and a central space portion. When the impeller rotates, air flowing into the central space portion through an air intake port of the casing passes through the inter-blade passages at an outward side. To reduce noise generated when the air passes through the inter-blade passages, each blade includes: multiple first concavo-convex portions, with a first surface side being concave and a second surface side on the other side being convex, from among a first and a second surface corresponding to a front and a rear surface of each blade; and multiple second concavo-convex portions, with the second surface side being concave and the first surface side being convex, contrary to the first concavo-convex portions.

Abstract: A combustion apparatus comprising includes: a combustion part for combusting fuel gas; a mixed gas supply channel for supplying a mixed gas of fuel gas and air to the combustion part; and a flame sensor located in or facing the mixed gas supply channel and capable of optically detecting a flame of a backfire from the combustion part to the mixed gas supply channel in the event of the backfire. The combustion apparatus further includes a shielding part that prevents travel of the light of the flame during normal combustion and the backfired flame of the backfire from the combustion part to the flame sensor.

Abstract: Provided is a blowing device capable of improving a noise reduction effect as compared with a conventional case, and a combustion device including the blowing device is provided. In a rear side shroud of an impeller configuring a blowing device, a first inclined surface portion that is inclined so as to be located frontward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region close to the outer peripheral edge, while a second inclined surface portion that is inclined so as to be located rearward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region closer to the center than the first inclined surface portion.

Abstract: An air blower and a combustion device including the air blower are provided. An air blower includes an impeller housed in a casing and rotating. The impeller includes multiple blades to form multiple inter-blade passages, and a central space portion. When the impeller rotates, air flowing into the central space portion through an air intake port of the casing passes through the inter-blade passages at an outward side. To reduce noise generated when the air passes through the inter-blade passages, each blade includes: multiple first concavo-convex portions, with a first surface side being concave and a second surface side on the other side being convex, from among a first and a second surface corresponding to a front and a rear surface of each blade; and multiple second concavo-convex portions, with the second surface side being concave and the first surface side being convex, contrary to the first concavo-convex portions.

Abstract: Provided is a water heater including a burner that receives a supply of combustion air from a fan, a heat exchanger having a heat transfer tube, and a combustion chamber case in which a combustion chamber of the burner is formed in the interior thereof and which is to be capable of guiding combustion gas generated by the burner to the heat exchanger. The water heater further includes a unit case that surrounds the combustion chamber case, and a region on the outside of the combustion chamber case within the unit case serves as an air pressure chamber having a higher pressure than the combustion chamber. Thus, combustion gas leakage to the outside can be prevented or suppressed appropriately by means of a simple configuration.

Abstract: Provided is a blowing device capable of improving a noise reduction effect as compared with a conventional case, and a combustion device including the blowing device is provided. In a rear side shroud of an impeller configuring a blowing device, a first inclined surface portion that is inclined so as to be located frontward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region close to the outer peripheral edge, while a second inclined surface portion that is inclined so as to be located rearward toward the radial outer side is formed in a front surface portion of the rear side shroud in a region closer to the center than the first inclined surface portion.

Abstract: Provided is a water heater including a burner that receives a supply of combustion air from a fan, a heat exchanger having a heat transfer tube, and a combustion chamber case in which a combustion chamber of the burner is formed in the interior thereof and which is to be capable of guiding combustion gas generated by the burner to the heat exchanger. The water heater further includes a unit case that surrounds the combustion chamber case, and a region on the outside of the combustion chamber case within the unit case serves as an air pressure chamber having a higher pressure than the combustion chamber. Thus, combustion gas leakage to the outside can be prevented or suppressed appropriately by means of a simple configuration.

Abstract: A burner case and a burner device provided with the burner case are disclosed. A cover for closing an opening of a case body of the burner case is attached to the case body by a first caulking portion and a second caulking portion. A first caulking direction and a second caulking direction intersect with each other, the first caulking direction is a direction in which a first attachment piece and a first facing portion, those constituting the first caulking portion, face each other and are caulked, the second caulking direction is a direction in which a second attachment piece and a second facing portion, those constituting the second caulking portion, face each other and are caulked. Thus, the case body and the cover are not required to be screwed or the number of the screws is reduced, and leakage of gas from the burner case to outside is prevented.

Abstract: A cover member of a gas supply manifold has a bent rising wall portion that is formed by bending a part of the cover member so as to rise in an opposite direction of a main body. The bent rising wall portion is in a form of a loop surrounding the entire circumference of a gas supply flow path and an area around the gas supply flow path. Such configuration increases the rigidity of the cover member and prevents large distortion of the cover member and leakage of gas from the gas supply flow path. As a result, the thickness of the cover member is reduced and the weight and the production cost of the gas supply manifold are also reduced.

Abstract: A combustion apparatus includes a burner and a heat shield plate. The heat shield plate includes a main plate portion located on a lateral side of a flame formation region above the burner to erect, a stepped portion protruding from a lower end of the main plate portion toward the burner and set at approximately the same height as that of a flame hole surface of the burner, and air passage holes provided in the stepped portion. The main plate portion is provided with a facing wall portion which protrudes from a middle part of the main plate portion in a vertical height direction thereof toward the flame formation region and faces the air passage holes so as to be subjected to a collision with air travelling upward from the air passage holes. This configuration allows the heat shield plate to be properly cooled/protected, while reducing consumed air.

Abstract: A cover member of a gas supply manifold has a bent rising wall portion that is formed by bending a part of the cover member so as to rise in an opposite direction of a main body. The bent rising wall portion is in a form of a loop surrounding the entire circumference of a gas supply flow path and an area around the gas supply flow path. Such configuration increases the rigidity of the cover member and prevents large distortion of the cover member and leakage of gas from the gas supply flow path. As a result, the thickness of the cover member is reduced and the weight and the production cost of the gas supply manifold are also reduced.

Abstract: A burner case and a burner device provided with the burner case are disclosed. A cover for closing an opening of a case body of the burner case is attached to the case body by a first caulking portion and a second caulking portion. A first caulking direction and a second caulking direction intersect with each other, the first caulking direction is a direction in which a first attachment piece and a first facing portion, those constituting the first caulking portion, face each other and are caulked, the second caulking direction is a direction in which a second attachment piece and a second facing portion, those constituting the second caulking portion, face each other and are caulked. Thus, the case body and the cover are not required to be screwed or the number of the screws is reduced, and leakage of gas from the burner case to outside is prevented.

Abstract: A combustion apparatus includes a burner and a heat shield plate. The heat shield plate includes a main plate portion located on a lateral side of a flame formation region above the burner to erect, a stepped portion protruding from a lower end of the main plate portion toward the burner and set at approximately the same height as that of a flame hole surface of the burner, and air passage holes provided in the stepped portion. The main plate portion is provided with a facing wall portion which protrudes from a middle part of the main plate portion in a vertical height direction thereof toward the flame formation region and faces the air passage holes so as to be subjected to a collision with air travelling upward from the air passage holes. This configuration allows the heat shield plate to be properly cooled/protected, while reducing consumed air.

Abstract: There is provided a flame hole formation member 7 which is inserted and mounted from above in a third plate member 6 used to form a central rich-side flame hole row 33. As the flame hole formation member 7, a pair of flame hole formation parts 71, 71 each used to form a respective lean-side flame hole row 34 are connected by bridge formation parts 72, 72 at their upper end positions, with a predetermined distance held between the flame hole formation parts 71, 71. The bridge formation part 72, 72 is fitted from above into an engagement groove 332 formed in the upper end edge of the third plate member 6, whereby the pair of the flame hole formation parts 71, 71 are assembled so as to sit astride the upper end edge of the third plate member 6.

Abstract: A row of rich-side flame holes is centrally arranged. Two rows of lean-side flame holes are arranged on both sides of the rich-side flame hole row, respectively. In addition, two rows of rich-side flame holes are arranged on the outsides of the two lean-side flame hole rows, respectively. A lower end part of a central rich-side burner part is projected into a tubular part into which the rich-side mixture is introduced, and communication holes in fluid communication with an inner space are formed in walls on both sides so as to pass completely therethrough in alignment with each other. Each communication hole has a larger diameter than an inner width P and is disposed at a potion situated nearer to the upper of the tubular part and nearer to the front so as to leave, at the rear, a space in which dust p particles are accumulated.

Abstract: A rich-lean combustion burner has a supply channel through which a lean-side mixture is supplied to lean-side flame holes; and a supply channel through which a rich-side mixture is supplied to rich-side flame holes. The supply channels are partitioned from each other. A third plate member including a pair of plate parts which are bent to form a V shape at its lower end edge as a fold line is employed to form a central rich-side burner part. A slit part is partitioned and formed between side edges of a pair of first plate members on both longitudinal sides for forming lean-side flame holes on width-wise sides of the central rich-side burner part. With the lower end part in front, the V-shaped third plate member s inserted into the slit part, thereby being interposed between the first plate members.

Abstract: In a rich-lean combustion burner, each of outer rich-side flame holes disposed on both outer sides is supplied with rich-side mixture in the same amount and mixing state as the others. A lower end part of a central rich-side burner part is projected into an interior of a tubular part to which a rich-side mixture is introduced. First communication holes are opened, respectively, in both side walls of the lower end part. A second and a third communication holes in fluid communication with an outer rich-side burner part are opened in a tubular part. The second and the third communication holes are oriented so as to face each other without any obstruction, other than a space, therebetween. Furthermore, a pocket part which is a space part adapted to collect and accumulate dust particles is formed on the downstream side up to a closed end.

Abstract: A rich-lean combustion burner has a supply channel through which a lean-side mixture is supplied to lean-side flame holes; and a supply channel through which a rich-side mixture is supplied to rich-side flame holes. The supply channels are partitioned from each other. A third plate member including a pair of plate parts which are bent to form a V shape at its lower end edge as a fold line is employed to form a central rich-side burner part. A slit part is partitioned and formed between side edges of a pair of first plate members on both longitudinal sides for forming lean-side flame holes on width-wise sides of the central rich-side burner part. With the lower end part in front, the V-shaped third plate members inserted into the slit part, thereby being interposed between the first plate members.

Abstract: A row of rich-side flame holes of a combustion burner is arranged in center. Two rows of lean-side flame holes are arranged respectively on sides of the rich-side flame hole row. Two rows of rich-side flame holes are arranged respectively on the outsides of the two lean-side flame hole rows. Supply of lean-side mixture is provided to the lean-side flame hole rows from a tubular part. A lower end part of a central rich-side burner part is projected into a tubular part, into which the rich-side mixture is introduced, to establish lateral fluid communication, with its lower end edge placed in a state of non-contact with the inner surface of the tubular part. First communication holes in fluid communication with an internal space are opened in the lower end part. Communication holes in fluid communication with the outer rich-side flame holes are opened in the inside of the tubular part.

Abstract: A row of rich-side flame holes is centrally arranged. Two rows of lean-side flame holes are arranged on both sides of the rich-side flame hole row, respectively. In addition, two rows of rich-side flame holes are arranged on the outsides of the two lean-side flame hole rows, respectively. A lower end part of a central rich-side burner part is projected into a tubular part into which the rich-side mixture is introduced, and communication holes in fluid communication with an inner space are formed in walls on both sides so as to pass completely therethrough in alignment with each other. Each communication hole has a larger diameter than an inner width P and is disposed at a portion situated nearer to the upper of the tubular part and nearer to the front so as to leave, at the rear, a space in which dust p particles are accumulated.