The invention relates to a device for cleaning the pipes of the drinking water circuit of an aircraft, in which the device is independent of the aircraft and is connected to the circuit intermittently and supplied with liquid. The device is characterized in that it comprises a mobile chassis supporting a plurality of functional sub-assemblies required to produce a hot liquid, including a closed-furnace gas condensing boiler. The invention can be used to clean the pipes of aircraft.

A water heater is provided that can suppress backflow (entry) of drainage water into a fan from downstream of the fan in a path of a flow of combustion gas. The fan includes a fan case, an impeller housed within the fan case, a drive source attached to the fan case so as to drive the impeller, and a rotation shaft connecting the impeller and the drive source. An exhaust connection portion has a connection portion case and is provided with an exhaust port for emitting combustion gas delivered from the fan to outside of the water heater. The exhaust connection portion also has a drainage water discharge portion for discharging drainage water accumulated downstream of the fan in the path of the flow of combustion gas.

A combined hot water and air heating and conditioning system including a first heat exchanger, a heat pump, a chilling tower loop, a burner and a second heat exchanger to provide hot water, air heating and air cooling. The system provides hot water, air heating and cooling all in one single unit. The system utilizes a heat pump to remove heat from ambient air and transfer the rejected heat into a hot water system, thereby using waste heat to heat the hot water system. The system utilizes a heat exchanger not only for the purpose of transferring heat from a heating source to a fluid in the heat exchanger but also for the purpose of dissipating heat from the fluid in the heat exchanger to the surroundings of the heat exchanger, thereby allowing a heat pump to act both as an air heating and conditioning device.

The present invention relates to a method and equipment for recovering heat from exhaust gas removed from an industrial process, such as an electrolysis process for the production of aluminum. Heat is recovered by means of an extraction/suction system, where the exhaust gas contains dust and/or particles. The heat is recovered as the exhaust gas being brought into contact with heat-recovery elements. Flow conditions and the design of the heat recovery elements are such that the deposits of the dust and/or particles on the surfaces stated are kept at a stable, limited level. In preferred embodiments, the heat-recovery elements have a circular or an extended, elliptical cross-section and may be equipped with fins or ribs.

The present invention relates to a method and equipment for recovering heat from exhaust gas removed from an industrial process, such as an electrolysis process for the production of aluminum. Heat is recovered by means of an extraction/suction system, where the exhaust gas contains dust and/or particles. The heat is recovered as the exhaust gas being brought into contact with heat-recovery elements. Flow conditions and the design of the heat recovery elements are such that the deposits of the dust and/or particles on the surfaces stated are kept at a stable, limited level. In preferred embodiments, the heat-recovery elements have a circular or an extended, elliptical cross-section and may be equipped with fins or ribs.

The present invention becomes possible to employ a main microprocessor with a relatively lower number of input ports, whereby while maintaining the performance and function of a water heater, the cost of a control apparatus is cut down. Some of sensors, adapted for measurement of various parameters which are for use in operational control of the water heater and in need of immediate response, are connected to a main microprocessor 31. The other sensors that are not in need of an immediate response, such as an ambient temperature sensor 36, are connected only to a sub microprocessor 32 if the main microprocessor 31 does not have any extra analog signal input port. The sub microprocessor converts an analog signal from the sensor 36 which is connected only to the sub microprocessor into digital data. And the sub microprocessor transmits the digital data to the main microprocessor through communication therewith.

A tankless water heater includes a scale control module (SCM). The SCM is mounted inside or outside of a cabinet which encloses a heat exchanger and source of heat of the water heater. The SCM may include a connector and a cartridge removably attaching to the connector or may only include a cartridge permanently affixed to the tankless water heater. The tankless water heater includes a continuous water pathway inside the cabinet to supply water to all components of the tankless water heater, including the SCM. The tankless water heater receives supply water at its inlet, treats the supply water in the SCM to generate treated water having reduced scale-forming characteristics compared to the supply water, and heats the treated water in the heat exchanger to generate heated treated water.

A heated flue includes a flue section configured to be fluidly coupled to an exhaust outlet of a boiler. At least one heater is mechanically coupled to the flue section to heat an exhaust gas flowing within. A sensor is mechanically coupled to the flue section or disposed within the flue section. The sensor is configured to measure a parameter of the exhaust gas flowing within. A controller is operatively coupled to the at least one heater and the sensor. The controller is configured to control a temperature of the exhaust gas based on the parameter. A method to vent a condensing boiler into a non-condensing rated stack is also described.

An improved hot water pressure washer utilizes a combination of technologies to achieve lower emission levels and increased operational efficiency. A forced air natural gas or forced air oil burner utilizes a flue gas and recirculation line to lower carbon monoxide and NOx emissions from a burner. A flue gas heat exchanger is utilized to lower the temperature of the exhaust gas. The lower exhaust gas temperatures allow for lower cost materials to be utilized. The efficiency levels of a hot water pressure washer are increased over known devices.

An improved hot water pressure washer utilizes a combination of technologies to achieve lower emission levels and increased operational efficiency. A forced air natural gas or forced air oil burner utilizes a flue gas and recirculation line to lower carbon monoxide and NOx emissions from a burner. A flue gas heat exchanger is utilized to lower the temperature of the exhaust gas. The lower exhaust gas temperatures allow for lower cost materials to be utilized. The efficiency levels of a hot water pressure washer are increased over known devices.