Abstract: A heating and hot-water supply apparatus 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 entry passage, a hot-water supply passage, and a control means. The circulation passage connects an external heating terminal and the heat exchanger. The water entry passage supplies water of an external hot-water supply pipe and an external water supply pipe to the hot-water supply heat exchanger. The control means controls the distribution means to be adaptable to each of a heating operation and a hot-water supply operation. The control means prioritizes the hot-water supply operation when there is a hot-water supply request for warm water use in addition to a heating request, and prioritizes the heating operation when there is a temperature-maintaining request for maintaining a temperature of the hot-water supply pipe in addition to the heating request.

Abstract: Various implementations include a hot water heating system having a spine and two or more water heating units. The spine includes a top surface defining one or more top openings, two or more coupling areas, and cold water, hot water, and fuel manifolds. One or more top openings provide access to a cold water manifold inlet, a hot water manifold outlet, and a fuel manifold inlet. At least one of the coupling areas is located above another coupling area when the spine is oriented with the top surface facing upwardly. The water heating units are coupled to coupling areas such that a cold water inlet of the unit is fluidically coupled to the cold water manifold outlet, a hot water outlet of the unit is fluidically coupled to the hot water manifold inlet, and a fuel inlet of the unit is fluidically coupled to the fuel manifold outlet.

Abstract: A heating device includes a base member and a gas burner mounted in or on the base member. An upper housing located above the base member and a tabletop mounted above the upper housing. A hollow heat shield having a proximal end located on or near the base member, and a distal end located within the upper housing, and a support member extending between the base member and the upper housing or tabletop. The distal end of the heat shield extends beyond a proximal end of the upper housing, defining a region of vertical overlap between the heat shield and the upper housing.

Abstract: A heat exchanger prevents cracking in heat transfer plates while avoiding lowering heat-exchange efficiency. Heat transfer plates are arranged with a space between them, and a hollow pipe extends through the plates. A high-temperature gas flows through the space to exchange heat with a liquid in the hollow pipe. The heat transfer plates are elongated in the direction in which parts of the hollow pipe are aligned and can thus have thermal expansion accumulating in the elongation direction. The heat transfer plates each include a thermal expansion absorber between an edge of the heat transfer plate receiving inflow of the high-temperature gas and an inter-pipe portion between adjacent parts of the hollow pipe to absorb thermal expansion of the heat transfer plate. A selected one or more of the inter-pipe portions, rather than all, include the thermal expansion absorber.

Abstract: Aspects of the invention provide a heat exchanger that includes a shell coupled to a top tube sheet and a bottom tube sheet. The shell at least partially defines an interior region. The heat exchanger also includes a burner positioned to deliver combustion gases into the interior region. A plurality of tubes, configured to circulate a fluid therein, extend through the interior region around the burner. The heat exchanger further includes a divider that extends within the interior region from the top tube sheet to the bottom tube sheet and between one of the plurality of tubes and another non-adjacent tube of the plurality of tubes. The divider and the plurality of tubes define a receiving section of the interior region for receiving combustion gases from the burner and an exhaust section of the interior region in fluid communication with a combustion gas vent.

Abstract: A guide system including a top end, a bottom end, a lumen and a plurality of openings, the system is disposed within a coil lumen at the bottom end of the heat exchanger coil with the bottom end of the system extending beyond the bottom end of the coil in a direction from the top end to the bottom end of the coil, the system configured in a shape of the coil lumen and the openings are disposed on the bottom end of the system, wherein the heat exchanger is configured to channel the flue flow from a burner through a path to heat a fluid flow of the coil before entering the lumen of the system via the openings to avoid a pressure drop due to a tendency for the flue flow to follow a path defined by a shape of the bottom end of the coil.

Abstract: A guide system including a top end, a bottom end, a lumen and a plurality of openings, the system is disposed within a coil lumen at the bottom end of the heat exchanger coil with the bottom end of the system extending beyond the bottom end of the coil in a direction from the top end to the bottom end of the coil, the system configured in a shape of the coil lumen and the openings are disposed on the bottom end of the system, wherein the heat exchanger is configured to channel the flue flow from a burner through a path to heat a fluid flow of the coil before entering the lumen of the system via the openings to avoid a pressure drop due to a tendency for the flue flow to follow a path defined by a shape of the bottom end of the coil.

Abstract: A heater coil for heating a feedstock comprises an inlet manifold and an outlet manifold having longitudinal extensions that are parallel. A plurality of process tubes are suspended from and in fluid communication with the inlet manifold and the outlet manifold. Each process tube comprises an inlet leg coupled to the inlet manifold, an outlet leg coupled to the outlet manifold, and a U-shaped portion disposed between the inlet leg and the outlet leg for passage of the feedstock therethrough. The inlet manifold and the outlet manifold are elevated with respect to the plurality of process tubes. Each of the plurality of process tubes is aligned such that a width of the plurality of process tubes extends along a direction that is not perpendicular to the longitudinal extensions of the inlet and outlet manifolds.

Abstract: A high efficiency compact boiler is disclosed which includes a burner configured to introduce combustion gases into an interior region of the boiler, a heat exchange tube made of a length of finned tubing in the form of a helical coil positioned within the interior region of the boiler such that combustion gases from the burner can flow from a region inside the helical coil to a region outside the helical coil, and a floating baffle configured to redirect the flow of combustion gases around the finned tubing as it passes from the region inside the helical coil to the region outside the helical coil, the baffle being positioned proximal adjacent turns of the helical coil and having a coiled configuration corresponding substantially to the helical coil.

Abstract: A water heater apparatus includes an elongated radial burner extending along a longitudinal central axis of the apparatus. First and second concentric rows of longitudinally extending fin tubes around the radial burner. The fin tubes may have multiple wiped circumferentially laterally portions allowing close packing of the fin tubes for improved efficiency and reduced footprint.

Abstract: A submersible well pump is driven by an electrical motor. A thrust bearing module between the pump and the motor has a base secured to and extending downward from a housing. The base has a motor end connector and an axial bore in fluid communication with lubricant in the motor. A shaft extends through the bore and into the housing. A thrust bearing assembly has a lower end at an upper end of the base. A lubricant pump mounted in the bore and coupled to the shaft pumps lubricant upward into the chamber. A passage has an inlet port in the chamber and an outlet port within the bore for returning lubricant pumped by the lubricant pump. The passage extends internally through the base and has a number of turns encircling the bore.

Abstract: A heater having a burner, a first heat exchanger associated with the burner, a second heat exchanger above the first heat exchanger in fluid cooperation with the first heat exchanger and an ambient air intake blower above the second heat exchanger. The second heat exchanger comprises angularly disposed finned section so condensate within the second heat exchanger flows to a collection point and is collected in a trap. The trap includes a sensor to sense buildup of fluid in the trap with feedback to the heater controls. The heater may include a collection pan below the heat exchangers in fluid communication with the trap. In one aspect the collection pan may include a heating element to vaporize the fluid so that heated, humidified air is expelled through vents adjacent the base of the heater. In another aspect, the pan includes an ultrasonic vaporization element to vaporize fluid in the pan.

Abstract: It is common in heating systems, such as in a hot water heater for there to be a combustor with the exhaust gases from the combustor provided to a heat exchanger to heat up the water. Disclosed herein is an integrated heat exchanger and burner assembly in which the combustion occurs proximate the surface of the heat exchanger. Such a system may include at least one tube that is coiled into a number of turns, that is a tube coil with the at least one tube having an inlet and an outlet and the distance between adjacent turns is less than a predetermined distance, i.e. a the quench distance.

Abstract: A high turn-down burner adapted to receive a fuel flow for combustion. The burner includes a housing having a side wall with an interior surface forming an inner periphery, a bottom wall adjoining the side wall, a top wall adjoining the side wall and a plurality of apertures disposed on the side wall; a supply tube adapted through the top wall of the housing, the supply tube including a side wall having an outer surface forming an outer periphery, a top end, a bottom end, wherein the supply tube is adapted to receive the fuel flow at the top end of the supply tube; and a disk having an opening adapted to accommodate the supply tube, wherein the disk is configured to slide along a length of the supply tube within the space delineated by the inner periphery of the housing and the outer periphery of the supply tube.

Abstract: A water heater includes a water tank having an inlet and an outlet, and a flue extending through the tank. A nozzle is positioned near a first end of the flue, arranged so as to emit a fuel stream into the flue, and a flame holder is located within the flue in a position to receive the fuel stream and to hold a flame entirely within the flue. A controller variably controls a flow of fuel to the nozzle according to a temperature of water in the tank.

Abstract: Described herein are embodiments of systems and methods for oxidizing gases. In some embodiments, a reaction chamber is configured to receive a fuel gas and maintain the gas at a temperature within the reaction chamber that is above an autoignition temperature of the gas. The reaction chamber may also be configured to maintain a reaction temperature within the reaction chamber below a flameout temperature. In some embodiments, heat and product gases from the oxidation process can be used, for example, to drive a turbine, reciprocating engine, and injected back into the reaction chamber.

Abstract: A water heating apparatus includes a burner, a heat exchanger for heating hot and cold water with use of heat from the burner, a scale detector for detecting occurrence of scale clogging in the heat exchanger, a notifying unit for notifying an error when the scale detector detects occurrence of a scale greater than or equal to a predetermined amount, and a controller performing a control of allowing the notifying unit to notify an error and prohibiting combustion operation of the burner when the scale detector detects occurrence of a scale greater than or equal to the predetermined amount. The controller is configured to start a cleaning mode for cleaning inside the heat exchanger when the controller detects shifting operation to the cleaning mode after the combustion operation of the burner is prohibited.

Abstract: A hot water supply system provided on a water pipeline, which includes a water inflow side and a water outlet side. The hot water supply system includes a plurality of water heaters; each includes a conduit, a heating device, a calculating unit, and a control unit. The conduit includes an inlet section, an outlet section, and a heating section in sequence, wherein the inlet section and the outlet section are connected with the water inflow side and the water outflow side respectively; the heating device heats the heating section; the calculating unit estimates a heating workload needed. If the heating workload of any water heater exceeds a predetermined upper limit workload thereof, the control unit of one water heater controls the other idle heating device to heat water, which ensures that water temperature of water provided to the water outflow side would reach a demanded water temperature.

Abstract: A water heater, which includes a water pipe, a combustor, and a dry-boiling protector. The dry-boiling protector includes a first sensor, a second sensor, and a controller. The first sensor senses a resistance of water in the water pipe, and the second sensor senses a flow rate of the water in the water pipe. The controller is electrically connected to the first sensor and the second sensor to stop the combustor to heat water when a resistance sensed by the first sensor is higher than a critical resistance for a predetermined period, and a flow rate sensed by the second sensor is not zero.

Abstract: Heat exchanger comprising a first heat exchanging body having a first end and an opposite second end, at least a flue gas channel and at least a water channel, a longitudinal direction of the first body extending between the first and second end thereof, and a second heat exchanging body, having a first end and an opposite second end, at least a flue gas channel and at least a water channel, a longitudinal direction of the second body extending between the first and second end thereof, wherein the first end of the second body is connected to the second end of the first body, wherein a burner chamber is provided at the first end of the first body.

Abstract: An on-demand high volume capable water heating system for supplying a total heating power at a high turndown ratio of at least about 33.3:1 and at a total flowrate of from about 0.6 GPM to about 50 GPM. The water heating system includes multiple heat exchangers where each heat exchanger includes a fluid conductor and a controller, an exhaust manifold configured to receive exhaust from the multiple heat exchangers, eliminating the need for an exhaust for each of the multiple heat exchangers, a recirculation circuit fluidly connected to each of the multiple heat exchangers and an enclosure. Each controller is adapted to determine the portion of heating power each heat exchanger is required to contribute to the total heating power and the portion of the total flowrate flowing through the fluid conductor. The heat exchangers and recirculation circuit are located within the enclosure.

Abstract: A circulating-type hot-water supply device (1) is provided with a heat exchanger abnormality determining unit (62), which inhibits execution of a suitable temperature maintaining operation when the suitable temperature maintaining operation continued for a predetermined time or more and stops a circulating pump (25), and when a temperature rise range of a detected temperature of a heat exchanger outlet temperature sensor (2) after stopping the circulating pump (25) becomes equal to or more than a temperature rise threshold value determined according to a selected state of burner blocks (3a),(3b) in a combusted state immediately before stopping the circulating pump (25), determines that a heat exchanger is in an abnormal state.

Abstract: The invention relates to a low-noise gas instantaneous water heater, belonging to the technical field of gas appliances. The low-noise gas instantaneous water heater comprises a combustion device, a heat exchanger and a blower; wherein the combustion device, the heat exchanger and the blower are arranged such that a combustion flue gas is discharged after passing sequentially through the heat exchanger and the blower; the blower comprises a stepless speed regulating motor with a motor control panel and an impeller driven by the motor, and at least one thermal insulation device is arranged between the motor control panel and the combustion flue gas generated by the combustion device.

Abstract: A steam boiler includes a boiler housing. A helical coil for boiling water and superheating the wet steam is disposed within the boiler housing. A burner emits combustion gases which heat a heat emitter which is disposed in the inner space of the helical coil. Combustion gases from the burner enter the internal cavity of the heat emitter and then pass through perforations in the heat emitter before contacting the helical coil. As such, the heat emitter is heated by the combustion gases and serves as a radiant heat source for the helical coil.

Abstract: A catalytic tank heater includes a catalytic heating element supported on an LPG tank by a support structure that holds the element in a position facing the tank. Vapor from the tank is provided as fuel to the heating element, and is regulated to increase heat output as tank pressure drops. The heating element is internally separated into a pilot heater and a main heater, with respective separate fuel inlets. The pilot heater remains in continual operation, but the main heater is operated only while tank pressure is below a threshold. Operation of the pilot heater keeps a portion of the catalyst hot, so that, when tank pressure drops below the threshold, and fuel is supplied to the main heater, catalytic combustion quickly expands from the area surrounding the pilot heater to the remainder of the catalyst.

Abstract: An exhaust case having the first exhaust gas flow path for flowing combustion exhaust gas passing upward through a heat exchange, behind a water-shielding plate and for guiding the combustion exhaust gas onto the water-shielding plate toward an exhaust vent, and having the second exhaust gas flow path for flowing a part of combustion exhaust gas into a space between the water-shielding plate and a horizontal plate part and further into the exhaust vent. A ventilation hole is provided for an upright plate part extending from the rear end of the horizontal plate part in order to flow combustion exhaust gas into the space, and is provided in the substantially horizontal direction. Accordingly, the exhaust case is inhibited to become large scaled, and a superior exhaust noise-reduction effect, a suppression effect of combustion oscillation of the burner, and a waterproof performance are able to be achieved.

Abstract: An espresso machine with improved fluid and thermal control is disclosed. The machine can include a controller for feedback pressure control of vibratory solenoid pumps. The controller can monitor pump pressure and/or volume and provide real-time feedback control of the pump pressure and/or volume. The controller can control pump output by means of a direct current, variable frequency square wave, which can be regulated to maintain a desired pressure output. The controller can also control pump output by means of a direct current, variable pulse width square wave. The espresso machine can also include a thermoblock with improved thermal efficiency and temperature control. The thermoblock can comprise a one or more serpentine pathways to improve thermal transfer to the fluid therein. The thermoblock can also provide feedback control of the temperature of the fluid.

Abstract: A heat exchanger having a cylindrical body comprising an upper section, a lower section, a side water jacket surrounding the upper and lower sections, a top water jacket disposed atop the upper section and a gas exhaust disposed below the lower section. A water cavity is disposed substantially in the lower section while a gas cavity having a burner is disposed substantially centrally within the gas cavity. A plurality of water tubes disposed in a ring formation, connect the water cavity through the gas cavity to the top water jacket and a plurality of gas tubes also disposed in ring formations, connect the gas cavity through the water cavity to the gas exhaust. At least one of the gas tubes ring has a diameter that is greater than that of the water tubes ring.

Abstract: A condensing type hot water boiler comprises: a firebox casing that formulates a firebox in which fuel is combusted; a burner that ignites fuel furnished in the upper part of said firebox casing; a ventilator that supplies air to said firebox; a heat exchange casing, wherein heat is exchanged between hot water and the flame and combustion gas flowing in from said firebox, located at the lower part of said firebox casing; and a hot water coil formed to cover the inner wall of said firebox casing and in which hot water is received in the interior from said heat exchange casing for heat exchange with flame and combustion gas of the interior of said firebox.

Abstract: A heat exchanger includes an enclosure having a separator disposed therein that divides the heat exchanger into a mixing area and a heat exchange area. The mixing area is configured to receive a hot fume and droplets of a liquid for mixing with each other to form a fume-droplet vapor mixture. The mixture is configured to flow through orifices of the separator into the heat exchange area. A plurality of magazines is disposed within the heat exchange area of the first enclosure. Each magazine defines a cavity. The cavities are disposed in communication with one another. A lower-most magazine is configured to receive a receiver medium that is pumped through the cavity of each successive magazine to an upper-most magazine. The mixture is configured to circulate about the magazines to incrementally heat the receiver medium as the receiver medium is pumped through the cavity of each successive magazine.

Abstract: A modulating burner apparatus includes a variable speed blower feeding a multi-chamber burner having first and second burner chambers. A manifold system communicates the blower with the burner, and a flow control valve member is located between the blower and the second chamber of the burner. The flow control valve is configured to provide fuel and air mixture from the blower to only the first burner chamber at lower blower speeds of the blower and to both the first and second burner chambers at higher blower speeds of the blower.

Abstract: A fin includes a cut and raised slit and a cut and raised wall portion. The cut and raised slit is formed in a region adjacent to at least one through hole of a plurality of through holes in a first direction and has a tunnel-shaped hole extending in a second direction intersecting the first direction. The cut and raised wall portion is located in the second direction of the cut and raised slit, protrudes toward a main surface of the fin, and extends along the first direction. Thus, a heat exchanger and a water heater capable of sufficiently conducting an amount of heat of a combustion gas to a heat conduction pipe even in a blind spot of a flow of the combustion gas of the heat conduction pipe and suppressing noise can be realized.

Abstract: In a primary heat exchanger, a heat conduction pipe is arranged as one connected pipe in a lower stage and an upper stage in a manner extending back and forth through a plurality of fins. The heat conduction pipe is arranged such that a pitch between the heat conduction pipes in the upper stage is shorter than a pitch between the heat conduction pipes in the lower stage. In addition, the heat conduction pipe is arranged such that a position in a center of each heat conduction pipe in the upper stage in a second direction orthogonal to a first direction in which the heat conduction pipe extends and a position in a center of each heat conduction pipe in the lower stage in the second direction are displaced from each other.

Abstract: The present invention overcomes many of the disadvantages of prior art mobile oil field heat exchange systems by providing an improved frac water heating system. The present invention is a self-contained unit which is easily transported to remote locations. In one embodiment, the present invention includes a single-pass tubular coil heat exchanger contained within a closed-bottom firebox having a forced-air combustion and cooling system. In another embodiment, the present invention includes multiple, single-pass heat exchanger units arranged in a vertically stacked configuration. The rig also includes integral fuel tanks, hydraulic and pneumatic systems for operating the rig at remote operations in all weather environments. In a preferred embodiment, the improved frac water heating system is used to heat water on-the-fly (i.e., directly from the supply source to the well head) to complete hydraulic fracturing operations.

Abstract: The present invention overcomes many of the disadvantages of prior art mobile oil field heat exchange systems by providing an improved frac water heating system. The present invention is a self-contained unit which is easily transported to remote locations. In one embodiment, the present invention includes a single-pass tubular coil heat exchanger contained within a closed-bottom firebox having a forced-air combustion and cooling system. In another embodiment, the present invention includes multiple, single-pass heat exchanger units arranged in a vertically stacked configuration. The rig also includes integral fuel tanks, hydraulic and pneumatic systems for operating the rig at remote operations in all weather environments. In a preferred embodiment, the improved frac water heating system is used to heat water on-the-fly (i.e., directly from the supply source to the well head) to complete hydraulic fracturing operations.

Abstract: A latent heat recovery type water heater A being designed such that water flown in a secondary heat exchanger 2 is heated, and the heated water is supplied to a primary heat exchanger 1 and is further heated. A controller 4 compares heat exchange efficiency ? of the secondary heat exchanger 2 with a predetermined threshold value Th, and the controller 4 determines whether the primary heat exchanger 1 is in a normal condition or not. The threshold value Th is changed corresponding to temperature of inflow water to the secondary heat exchanger 2. Accordingly, an abnormality such as scale adherence in the primary heat exchanger 1 is accurately detected regardless of the fact that the primary heat exchanger 1 and the secondary heat exchanger 2 are connected by a bypass path or not.

Abstract: A novel water heat exchanger with a helix coil incorporated into a stainless steel elongated variable diameter cylindrical housing. A buffer tank is incorporated within the lumen of the helix coil. In one embodiment, the heat exchanger utilizes a radial direct-firing burner and a blower-driven hot flue gas to heat water for domestic and commercial use. In one embodiment, at least a rope seal is disposed between adjacent coil loops of a portion of the helix coil for enhancing heat transfer to the helix coil. In one embodiment, solar and electric heating systems are combined with the helix coil heat exchanger and disposed within the buffer tank to provide supplemental heating. In another embodiment, the heat exchanger further comprises a Stirling engine comprised of a free piston having hot and cold ends that is disposed within the cavity taken up the buffer tank, wherein the hot end receives heat from the burner and the cold end is cooled by the incoming cold water line to form an electric power generator.

Abstract: A continuous flow heater that mitigates the effect of altitude, characterized in that it consists of a combustion system with four mixers attached to a rectangular base into which the gas is injected and distributed through fifty small cavities is provided. The combustion system is attached to a heat transfer system. The continuous flow heater that mitigates the effect of altitude is suitable for altitudes greater than 2000 meters above the sea level without notable reductions in power or significant increases in polluting and toxic emissions. The combustion system has better air draft than conventional systems, enabling it to mitigate the reduction in the quantity of oxygen in the air at higher altitudes, improving the operation of the equipment compared to the operation of equipment already available on the market, and making a better use of non-renewable natural resources.

Abstract: A combustion apparatus for boiler includes an air supply device that varies a supply amount of combustion air, a fuel supply device that varies a supply amount of fuel, and a control device that controls the air supply device and the fuel supply device, obtains the supply amounts in accordance with respective combustion stages, and realizes the multiple combustion stages. The the control device controls the air supply device and the fuel supply device so as to return to a predetermined combustion stage when a request for transition cancel is received during transition from the predetermined combustion stage to another combustion stage, and controls so as not to perform the transition to the other combustion stage until a predetermined time period has elapsed.

Abstract: A method of assembling multiple low NOx burners (100), a low NOx burners (100) and a tankless gas-fired water heater (500) are disclosed. The method includes the step of assembling multiple bodies (152), each body (152) includes multiple first burner ports (135) connected to a first burner inlet (125) and multiple second burner ports (150) connected to a second burner inlet (140). The method also includes the step of selecting one of the bodies (152) and inserting a first inlet tube (120, 220, 320, 420) into the second burner inlet (140) to provide a fuel/air mixture to the second burner ports (150) at a first rate. The method also includes the step of selecting one of the bodies (152) and inserting a second inlet tube (120, 220, 320, 420) into the second burner inlet (140) to provide the fuel/air mixture to the second burner ports (150) at a second rate different from the first rate.

Abstract: The present invention overcomes many of the disadvantages of prior art mobile oil field heat exchange systems by providing an oil-fired heat exchange system. The present invention is a self-contained unit which is easily transported to remote locations. The present invention includes a single-pass tubular coil heat exchanger contained within a closed-bottom firebox having a forced-air combustion and cooling system. The rig also includes integral fuel tanks, hydraulic and pneumatic systems for operating the rig at remote operations in all weather environments. In a preferred embodiment, the oil-fired heat exchanger system is used to heat water on-the-fly (i.e., directly from the supply source to the well head) to complete hydraulic fracturing operations. The present invention also includes systems for regulating and adjusting the fuel/air mixture within the firebox to maximize the combustion efficiency. The system includes a novel hood opening mechanism attached to the exhaust stack of the firebox.

Abstract: Known chimneys or chimney furnaces use flue gas flow units for heating buildings, said devices having displaceable or fixed obstacles for deflecting flue gas for generating flue gas turbulence. The invention relates to a device and method for transferring heat through a flue gas discharge pipe (28) in which (44, 45) pivotal guide plates (37) are inserted in the longitudinal direction of the pipe run, at which the flue gas flow (22) is more or less deflected in a sinuous line as function of the pivot angle (24) of the guide plates (37) that can be adjusted during furnace operation. A fan (19) can increase the flue gas flow (22). An optional furnace heat exchanger (29) generates additional hot water as needed. The controller (5) activates the actuators for the fan (19), guide plate pivot angle setting (24), and at least one circulating pump (10 or 11) as a function of the prescribed controlled variables such as flue gas temperature, reservoir temperature, heat exchanger performance, or flue gas flow.

Abstract: A tank-tankless water heater includes primary and secondary heat exchangers, and a combustor for the production of flue gases. In operation, water is first heated as the water and flue gases flow through primary heat exchanger. The water flows into the tank where it is stored and again heated as the flue gases flow through the secondary heat exchanger. A pump moves the water from the secondary heat exchanger, through the primary heat exchanger, and back to the secondary heat exchanger for storage as needed to maintain the stored water at a desired temperature. Water is drawn from the secondary heat exchanger during initial demand to provide a ready source of hot water, and the hot water supply is maintained by the primary heat exchanger during sustained hot water draws. The primary heat exchanger may include a temperature or temperature differential control system.

Abstract: A gas-fired water heater including a storage tank, a combustion chamber, a burner for producing products of combustion, the burner positioned in the combustion chamber, a flue including a longitudinal axis, the flue extending from the combustion chamber through the storage tank, and an exhaust assembly positioned above the flue. The exhaust assembly includes a hood, a motor including a drive shaft, and a fan coupled to the drive shaft for rotation with the drive shaft about a rotational axis. The hood receives the products of combustion from the flue and directs the products of combustion at an acute angle toward the fan. The rotational axis is positioned at the acute angle relative to the longitudinal axis.

Abstract: A heater, comprising a fuel burner, a primary heat exchanger, and an enclosure around the fuel burner and primary heat exchanger and defining a gas flow path, wherein the enclosure further comprises a secondary heat exchanger and/or heat storage means.

Abstract: The present invention relates to a user activated hot water heater and control system for processing hot water to hot water output locations, e.g. faucet, shower, or the like, such that temperature fluctuations and delays in hot water delivery are reduced. The present invention provides energy savings resulting from smart activation of internal and/or external recirculation systems. Additionally, trickle flow is detected and responded to based on temperature responses at various points in the main flow line of the present configuration. Simultaneous internal and external recirculations are made possible with advantageous placement of a pump within internal and external recirculation loops and a solenoid valve within the internal recirculation loop. The present system further comprises a means for adjusting the pump action in response to a thermostatic valve, temperature sensors advantageously placed in the main flow line to reduce dead heading.

Abstract: To provide a boiler capable of realizing a reduction in O2, a reduction in NOx, and a reduction in CO. The present invention provides a boiler including: a premixed gas burner, and water tubes in close proximity to the premixed gas burner, characterized in that the premixed gas burner ejects a premixed gas toward the water tubes at a predetermined angle; and the boiler further includes a fuel supply portion capable of supplying at least one of a gas fuel and a premixed gas provided at a position on a downstream side of and spaced apart by a predetermined distance from the premixed gas burner.

Abstract: A high efficiency water heater comprising a generally cone shaped tank; an surrounding and spaced from the tank defining a passageway for flue gases between an inner surface of the enclosure and the outer surface of the tank, said enclosure having an outlet for flue gases; a burner communicating with the interior of said enclosure, and means for providing combustion air to said burner. The preferred embodiment includes baffle means attached to the outer surface of the tank for increasing heat transfer. One embodiment has a conduit passing vertically through the tank, and wherein the burner is disposed in an upper region and communicating with the conduit, and includes a fan for directing flue gases downward through the conduit and subsequently into and through said passageway between the inner surface of the enclosure and the outer surface of the tank.

Abstract: To provide a boiler equipped with a water tube group performing heat recovery effectively and having expansion heating surfaces (fins or the like) of high durability, the present invention provides a boiler (1) including: a boiler body (10) having an inner water tube group (20) and an outer water tube group (30) that are arranged in an annular fashion; and a burner (40) arranged at a central portion of the inner water tube group (20), in which: intervals between adjacent inner water tubes constituting the inner water tube group (20) are closed except for portions where a gas flow passage is provided; and stud fins (22 and 32) are provided on a portion of at least one of the inner water tube group (20) and the outer water tube group (30) in a vicinity of the gas flow passage.

Abstract: A hot gas water heater has a housing, and at least a pair of concentric coils in the housing through which liquid to be heated is sequentially passed. Each coil has a helical tube with adjacent turns connected by a web member such that the tube and web member form an imperforate coil wall. Hot gas passes sequentially between the coils in co-current flow with liquid flow in one adjacent coil and counter-current flow with liquid flow in another adjacent coil.