Abstract: A premixing device includes: a gas flow passage forming member in which an x direction is used as an axial length direction, and a Venturi-shaped gas flow passage into which air can flow in from the outside is formed inside; and a blade portion positioned in the gas flow passage, extending in a y direction, and equipped with a fuel gas outlet. The blade portion includes first and second blade portions spaced apart from each other in a z direction, and an air flow path near the center through which a part of the air flows is formed between these first and second blade portions. At least one of a pair of surfaces of the first and second blade portions facing each other is equipped with an inner bulging portion that bulges in the z direction so as to squeeze a part of the air flow path near the center.

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: A hot water supply device and a hot water supply system are provided. A controller actuates a circulation pump at a constant output and actuates a heating mechanism for heating by a combustion mechanism when an instantaneous hot water operation is started in response to a temperature drop of a fluid while hot water supply of a hot water supply tap is stopped, until a minimum drive time elapses. The minimum drive time is set based on a flow rate detection value of a flow rate detector under a condition that the circulation pump is actuated at a predetermined constant output and an instantaneous hot water circulation path is formed.

Abstract: A heating and hot-water supply device includes a combustion means, a heat exchanger, a circulation passage, a circulation means, a bypass passage, a distribution means, a hot-water supply heat exchanger, a water supply passage, a hot-water supply passage, and a control means. The heat exchanger heats a heating heat-medium to a target heat medium temperature. The distribution means distributes the heating heat-medium to the circulation passage and the bypass passage. The control means is capable of adjusting a distribution ratio of the distribution means to be adaptable to a heating operation, a hot-water supply operation, and a simultaneous heating and hot-water supply operation. At the time of transition from the heating operation to the simultaneous heating and hot-water supply operation, in a case where the heating terminal for performing heating is a warm air heater, the control means raises the target heat medium temperature.

Abstract: A heat exchanger includes a plurality of heat transfer tubes housed in a predetermined case, a connecting tube body for connecting the plurality of heat transfer tubes, a predetermined tube expansion portion provided on each heat transfer tube, a first peripheral wall portion provided on the tube expansion portion, and a second peripheral wall portion that is positioned on an end portion of the connecting tube body and fitted to the tube expansion portion, wherein the first and second peripheral wall portions have different sectional shapes and are fitted together in a partial contact state including predetermined contact and non-contact portions. According to this configuration, the heat transfer tubes can be fixed to a side wall portion of the case and the connecting tube body can be connected to the heat transfer tubes easily and appropriately.

Abstract: A hot water device includes a heat exchanger and an apparatus to which the heat exchanger is to be connected. First and second cases for the heat exchanger and the apparatus to which the heat exchanger is to be connected include first and second flange portions laid over each other and welded together. The first and second flange portions are each demarcated into a corner flange portion corresponding to one of first and second corner portions, and into a non-corner flange portion other than the corner flange portion. The non-corner flange portions protrude more to the outside of the first and second cases than the corner flange portions.

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 heat exchanger and a water heater are provided. The heat exchanger is provided with an auxiliary member including a trunk pipe joint portion joined to a trunk pipe and an extension portion extending from the trunk pipe joint portion toward a plurality of fins. The plurality of fins is provided apart from a sidewall portion so as not to directly contact the sidewall portion of a case, the extension portion of the auxiliary member includes an entry portion that enters between the plurality of fins and the sidewall portion, and a first abutment portion which is provided in the entry portion and abuts outer end portions of the plurality of fins, the first abutment portion is separated from the sidewall portion, and a space portion in which inflow of the heating gas is suppressed is formed between the first abutment portion and the sidewall portion.

Abstract: A linked hot water supply system includes: multiple combustion hot water supply devices arranged in parallel between a water supply pipe and a hot water supply pipe; and a control means, changing a number of operated units of the hot water supply devices to adjust a heating capacity according to a hot water consumption. The hot water supply devices each includes a water passing volume detection means detecting a water passing volume of tap water introduced from the water supply pipe and an inlet water filter installed to an introduction part of the tap water from the water supply pipe. If the hot water supply devices are operating at a same time, the control means makes a determination on blockage of the inlet water filter installed in each of the hot water supply devices by comparing the water passing volumes of the hot water supply devices in operation.

Abstract: A metal bend pipe having a bend portion bent in a semi-circular arc shape is provided, in which an identification part that enables one of the two end portions of the bend portion to be identified as the bending-start side or the bending-end side is provided, and the identification part is integrally formed as a protruding and/or recessed three-dimensional region. Thus, it is possible to easily and reliably identify which of the two end portions of the bend portion is the bending-start side or the bending-end side.

Abstract: In a pipe machining apparatus A, a region of a part including a first pressure contact part 61a which comes into pressure contact with a first portion 11a of a pipe P in a lower clamper part 6 of a clamping device C serves as a first movable clamper part 61 which is separate from a different region 63 of the lower clamper part 6, and the pipe machining apparatus A includes a first displacement member 8A that is able to displace the first movable clamper part 61 in a predetermined first direction D1 after machining of the pipe P ends. According to such a constitution, a pipe machining apparatus capable of appropriately resolving aggravation of workability of removing a pipe caused by a part of the pipe which comes into pressure contact with a lower clamper part of a clamping device can be provided.

Abstract: A heat exchanger includes a case, a first and second heat exchanger disposed inside the case, a partition member disposed inside the case, and a duct. The case has a first side wall and a second side wall spaced apart from and facing each other in a first direction, a third side wall and a fourth side wall spaced apart from and facing each other in a second direction orthogonal to the first direction, and a bottom wall. A gas outlet communicating with an interior of the case is formed in the first side wall. The first heat exchanger is farther from the bottom wall than the second heat exchanger in a third direction orthogonal to the first and second directions. The second heat exchanger includes meandering heat transfer tubes meandering within a plane orthogonal to the first direction and overlapping along the first direction.

Abstract: A tank includes: a bowl-shaped head having a peripheral wall whose base end side is open; and a tubular body member having an end in an axial length direction joined to the head. The peripheral wall of a region of the head close to a base end is an inclined peripheral wall whose inner diameter increases toward the base end. The end of the body member is inserted inside the inclined peripheral wall of the head and is joined to an inner peripheral surface of the inclined peripheral wall via a weld. A mark available for use in determining a position of the end of the body member is provided in a position on an outer peripheral surface of the body member on a central part side of the body member in the axial length direction with respect to the head and away from the end by a predetermined dimension.

Abstract: A hot water supply device including an inlet pipe, an outlet pipe, a burner unit, a heat exchanger, an exhaust aperture, a first temperature sensor detecting a measured exhaust temperature of the exhaust gas, a second temperature sensor detecting a water temperature of water entering the inlet pipe, and a processor. The processor is configured to obtain an error between the measured exhaust temperature and an estimated exhaust temperature, and detects that scale clogging has occurred inside the heat exchange tubing based on an index which is generated using the error between the measured exhaust temperature and the estimated exhaust temperature. The estimated exhaust temperature is a first predetermined value that is determined using a numerical equation which has at least the water temperature of water entering the inlet pipe and a scale number of the hot water supply device as variables of the numerical equation.

Abstract: In an immediate hot water supply operation mode in which a circulation pump is activated while a hot water supply faucet is closed, a water heating apparatus forms an immediate hot water supply circulation path by an inner path including a water entry path, a heat exchanger, and a hot water output path and an outer path bypassing the hot water supply faucet, as being combined. A controller stores as an actual flow rate value for each immediate hot water supply operation mode, a flow rate detection value by a flow rate sensor at predetermined timing, and calculates a flow rate learning value based on a plurality of stored actual flow rate values. When the flow rate detection value becomes larger than a criterion value set in accordance with the flow rate learning value, use of the hot water supply faucet is detected and the circulation pump is deactivated.

Abstract: The disclosure includes a hot water circulation device, and a hot water device monitoring system including a circulation passage; a circulation pump circulating hot water in the circulation passage; a closed expansion tank in which a water chamber communicating with the circulation passage and an air chamber filled with a predetermined pressure in initial state are partitioned by a diaphragm; and a control unit controlling hot water circulation. The hot water circulation device includes an air chamber pressure sensor detecting pressure in the air chamber; a closing valve cutting off water chamber from the circulation passage; and an open valve opening to atmosphere from between closing valve and water chamber. The control unit closes closing valve and opens opening valve during hot water circulation, detects pressure in the air chamber by the air chamber pressure sensor, and issues a warning notification when the pressure is not within predetermined pressure range.

Abstract: The disclosure provides a water heater. The water heater includes a water heater main body portion including a heat exchanger and a combustion device; a fan and a motor for driving the fan; an exterior case; and an air supply adapter mounted to an upper wall portion of the exterior case. The combustion device and the motor are positioned in a region near an upper portion within the exterior case. The combustion device is at least partly positioned between the air supply adapter and the fan in a plan view. An air outlet of the air supply adapter opens substantially horizontally, avoiding a direction directly facing the motor. The air flowing out from the air outlet is changed in direction by a side wall portion of the exterior case and flows to reach a portion of the motor.

Abstract: The disclosure provides a combustion device for burning LP gas filled in a gas cylinder as fuel in a combustion unit. The combustion device includes: a control unit for controlling a combustion operation based on a preset operation table such that a combustion output reaches a target output, and an output detection part for detecting the combustion output. In a case where the combustion output detected by the output detection part is risen by a reference value or more relative to the target output, the control unit notifies of a lowering in the remaining amount of LP gas in the gas cylinder.

Abstract: A premixing flow path forming member of a premixing device includes a member whose attachment mode can be changed, and flow path resistance of a fuel gas flow path can be changed when the attachment mode of the member is changed.

Abstract: A connected-type hot-water supply system includes hot-water supply apparatuses connected in parallel and a control means. The control means sets one main hot-water supply apparatus and sub-hot-water supply apparatuses, and performs leveling control of cumulative loads of the hot-water supply apparatuses by setting the main hot-water supply apparatus based on sequential rotation among the hot-water supply apparatuses. The control means includes a failure sign response mode in which it is determined whether there is a failure sign respectively for components of the hot-water supply apparatuses, and when a component of a part of hot-water supply apparatuses is a failure sign component determined to have a failure sign, a main use time of a hot-water supply apparatus having the failure sign component is increased, and the main use time is a main use time of serving as the main hot-water supply apparatus in the leveling control.