A heating apparatus is disclosed. The heating apparatus comprises a PTC heating element, a first electrode, a second electrode, a first protection layer, a second protection layer, a first interlayer, and a second interlayer. A hardness of the first protection layer is greater than that of the first interlayer. A hardness of the second protection layer is greater than that of the second interlayer.

The invention relates to heat engineering, power engineering and the field of electric heating of liquids, water for instance; it can be used in circulation water heating systems and hot water supply, and as a universal device for diverse electric heaters. An object of the invention are to enhance the ease of fabrication, fabricability, and operability for block electrodes and electrode heating boilers on the whole, to increase the reliability of device both in static and dynamic modes ones. The invention meets an object of extended performance capabilities, versatility and flexibility of the device, potential diversification and enhancement of adaptability in solving particular problems. Moreover, the invention allows improvement of convection in water heating boilers and reduction of uniformity of sludge and rust deposition on electrodes thus increasing the heater effective performance time. The invention object comprises an improvement of protection against breakdowns between the electrodes as well, phase current load imbalance reduction, electrode protection against non-uniform deformation during operation in dynamic conditions. It is also an object of the invention to extend i the range of constructional capacity control without design and dimensional changes. FIG. 2 provides a schematic of electrodes (1) arrangement on the basis (3) located on the inner case (2) side with electrodes (1) slightly deviating from the longitudinal symmetric axis of the case (2) and irregularly spaced on the basis, electrode longitudinal axes deviating from each other at small angles. (4)—outer electrode terminals (1).

[Problems to be Solved] An exhaust duct (4) for assembly into a combustion apparatus has: a burner (1) to eject air-fuel mixture downward; and a combustion box (3) disposed on a lower side of the burner (1). The exhaust duct includes: a riser duct section (42) elongated in a vertical direction and having, at a lower portion thereof, an inlet port (41) connected to an exhaust port (35) for combustion gas which is opened in a lower portion of the combustion box (3); and a flat horizontal duct section (43) bent at an upper end of the riser duct section (42) so as to be elongated forward. By restraining the resonance of an upper wall part (431) and a lower wall part (432) of the horizontal duct section (43), noises due to resonance sounds are reduced.

[Solving Means] The natural frequencies in an upper wall part (431) and the lower wall part (432) of the horizontal duct section (43) are varied from each other. For example, the lower wall part (432) is fixed to a burner body (11) in order to vary the natural frequencies of the upper wall part (431) and of the lower wall part (432) from each other.

The description relates to a vehicle heating system having at least one heat transfer device through which air can flow to be heated and at least one heating device which is attached to the heat transfer device and which each involves at least one heating element arranged between two contact plates, said heating element being held by a positioning frame which is attached to one of the contact plates. The contact plates of the heating devices are each held in a positioning frame to which they are attached.

A combustion apparatus includes a burner (11), a heat exchanger (12) accommodated in a casing (20), an exhaust passage (22B) provided to one side surface side of the casing (20), and an exhaust resistance member (5) having a plurality of ventilation ports (50) through which combustion exhaust gas passes, wherein at least one part of the ventilation ports (50) has an elongated hole shape extending in the flow direction of the combustion exhaust gas from beneath the casing (20) to the exhaust passage (22B).

The embodiments of the present application disclose a gas premix burner and a gas water heater. The gas premix burner has a combustion direction, the gas premix burner can be matched and connected with a premix chamber that is disposed upstream the combustion direction of the gas premix burner, gas and air can be burned by the gas premix burner after mixed in the premix chamber; the gas premix burner comprising: a burner substrate, a main combustion hole provided on the burner substrate; an auxiliary combustion hole disposed downstream the main combustion hole along the combustion direction on the burner substrate; an auxiliary flame of the auxiliary combustion hole intersects a main flame of the main combustion hole. The present application provides the main combustion hole upstream the auxiliary combustion hole along the combustion direction, since the main flame is usually larger in scale than the auxiliary flame, by providing the main flame upstream the auxiliary flame, it will be easier for the auxiliary flame and the main flame to intersect each other, and then the effect of stabilizing the flame is realized by opposed flames formed by the auxiliary flame and the main flame.

A heat exchanger which is used primarily in oil and gas operations to heat tanks of liquids, such as drilling mud, water, heavy oil or other such fluids from freezing or becoming too viscous to pump.

An electric heating device for emitting a heated air flow, in particular for a sanitary room or washroom in a rail-borne vehicle, includes an air duct, a fan generating the air flow, a heating element heating the air flow and a first over-temperature switch. The first over-temperature switch can reversibly switch off the heating element when a first over-temperature is exceeded. A second over-temperature switch can irreversibly switch off the heating element when a second over-temperature is exceeded. The second over-temperature switch is disposed in a recess, depression or opening formed in the air duct. The second over-temperature switch has a disconnect or isolating switch to be thermally triggered for switching off the heating element. The thermally triggered disconnect or isolating switch can be triggered by a glass sphere or bead that breaks when the second over-temperature is exceeded.

The present disclosure discloses an ignition temperature control apparatus of a gas water heater, comprising: a heat exchanger made of stainless steel; a combustion device which supplies high-temperature flue gas to the heat exchanger; a water passage communicated with the heat exchanger; a first temperature detection device provided on the heat exchanger or on the water passage; a controller, wherein if a temperature detected by the first temperature detection device is lower than or equal to a first preset temperature or a rate of decline of a temperature detected by the first temperature detection device is higher than or equal to a first preset value the controller controls the combustion device to operate in such a state that a requirement for thermal bearing capacity of the heat exchanger made of stainless steel is satisfied. The heat exchanger of the ignition temperature control apparatus of the gas water heater of the present disclosure, which is made of stainless steel, has good thermal inertia and excellent thermal insulation properties, and thus the combustion device is started for heating when the ignition temperature control apparatus of the gas water heater is in a stop state, such that it is possible to ensure that the heat exchanger will not fail while an anti-freezing effect can be achieved.

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.