The present invention includes: a laminated structure of an insulation substrate; a resistance pattern laminated on one side of the insulation substrate with a pure metal or an alloy which is a mixture of two or more metals at a predetermined ratio and having a resistance value which is set by a pattern having a length and a cross-sectional area; a first insulator layer coated on an upper surface of the resistance pattern by a predetermined method to protect and insulate the resistance pattern; a conductor layer in which a metal material is deposited on the upper surface of the first insulator layer by a predetermined method; and a thin film protective layer deposited on the upper surface of the conductor layer to provide insulation from the conductor layer, waterproofing, corrosion resistance, and chemical resistance.

The present invention provides a hot water supply device. When a hot water supply operation is started in response to an instruction for checking a heat exchange state, a heat exchange state determiner 12 measures a post-boiling temperature Tup, which indicates the rise width of a temperature detected by a heat exchange outlet temperature sensor 26 from the point when the hot water supply operation stopped, and outputs a heat exchange success report if the post-boiling temperature Tup is lower than a first threshold temperature. Further, when the hot water supply operation is started independently of the instruction for checking a heat exchange state, the heat exchange state determiner 12 outputs a report of clogging of a heat exchanger if the post-boiling temperature Tup is higher than a second threshold temperature Bth, which is higher than the first threshold temperature Ath.

A door with a gas burner on an inner surface and a system for carrying a combustible gas to the burner on the outer surface thereof. The door comprises a pair of metal sheets rigidly connected to one another at the edges thereof, each sheet having input and output openings for the gas mixture that are mutually separated in order to leave an inner space receiving a deflector plate serving as a thermal shield to be swept over on either side by the flow of the gas mixture supplying the burner. This arrangement reduces heat loss through the door; thus, keeping the outer surface cold, avoiding the risk of burns, and preheating the gas mixture. The invention can be used in heating appliances.

An inter-axial inline fluid heater is presented. The inter-axial inline fluid heater includes an outer retaining sheath defining a first area, and an interior flow tube disposed within the outer sheath and capable of having fluid flow therethrough. Further, the interaxial inline fluid heater includes a resistance wire disposed between the interior flow tube and the outer retaining sheath, the resistance wire capable of producing heat for heating a fluid passing through the interior flow tube when power is applied to the resistance wire. Also includes is a dielectric heat transfer material disposed between the interior flow tube and the outer retaining sheath and surrounding at least a portion of the resistance wire.

A system for heating a pipeline comprises a heater operable to heat a fluid, a supply line and a return line. A first strap is positioned at a first portion of a pipeline. A first pocket of the first strap holds the supply line in thermal contact with the first portion of the pipeline. A second pocket of the first strap holds the return line in thermal contact with the first portion of the pipeline. A second strap is positioned at a second portion of the pipeline. A third pocket of the first strap holds the supply line in thermal contact with the second portion of the pipeline. A fourth pocket holds the return line in thermal contact with the second portion of the pipeline.

An electrically conductive resistive layer is produced by thermally spraying an electrically conductive material onto the surface of a non-conductive substrate. Initially, the material layer arising therefrom has no desired shape. The material layer is then removed in certain areas so that an electrically conductive resistive layer having said desired shape is produced.

A froth heater can include an outer case defining an inner cavity, an inlet in fluid communication with the inner cavity, and an outlet in fluid communication with the inner cavity. The froth heater can include a heater core inserted into inner cavity and configured to form a flow path between an inner wall of the outer case and the heater core between the inlet and the outlet. The heater core can include a core cavity configured to receive a heater therein to heat the heater core.

A froth heater can include an outer case defining an inner cavity, an inlet in fluid communication with the inner cavity, and an outlet in fluid communication with the inner cavity. The froth heater can include a heater core inserted into inner cavity and configured to form a flow path between an inner wall of the outer case and the heater core between the inlet and the outlet. The heater core can include a core cavity configured to receive a heater therein to heat the heater core.

A combustion device including a chamber, a burner, a fan case, and a fan is provided. The chamber has a top wall. On the top wall, an inflow port penetrating through the top wall along a first direction and in communication with an internal space of the chamber is formed. The burner is attached to the chamber, so as to be spaced apart from and face the top wall in the first direction. In the fan case, a discharge port and an intake port penetrating through the fan case along the first direction and in communication with an internal space of the fan case are formed. The discharge port is connected with the inflow port. The fan is provided in the internal space of the fan case. A rotation axis of the fan is along the first direction.

A hot water appliance includes a housing defining an inner space; a heat source arranged in the inner space of the housing and comprising at least one burner; a flue gas discharge arranged in the inner space of the housing and configured to discharge combustion gases of the at least one burner therethrough; and a heat exchanger arranged in the inner space of the housing and associated with the flue gas discharge. The combustion gases of the at least one burner form a first heat exchanging fluid of the heat exchanger associated with the flue gas discharge. A flue gas discharge for a hot water appliance and a method for heating a fluid are also described.