RU35495U1 - Electric gas heater - Google Patents

Description

Electric gas heater

The proposed utility model relates to the field of gas heating and can be used, in particular, in installations for gas-dynamic spraying of materials.

Known flow heater of the current environment / Utility model of the Russian Federation No. 24611, IPC: Н05В 3/40, F24H 3/04 / in the form of a heat pipe heated by electric current.

The disadvantages of the known device are the low efficiency of heating gases, low heating rate and reaching a stationary temperature regime at various flow rates, pressures and flow rates of the heated gas. The known device has a large heat loss.

The technical problem to be solved was to create an electric gas heater, which allows for a high heating rate and access to a stationary thermal regime of gas heating at various flow rates, pressures and flow rates, and also allows to reduce heat losses.

The essence of the utility model is that the electric gas heater includes a heat-generating channel in the form of a conductive pipe. A distinctive feature of the utility model is that the pipe is rolled into a spiral with a variable radius of curvature, placed in a heat-insulating casing and provided at the ends with current-disconnecting flanges, with which it is attached to the heat-insulating casing and the nozzles for the input of the heated gas and the outlet of the heated gas, while the heat-insulating casing placed in the outer casing with a gap between their walls and equipped with inlet and outlet fittings for entering into the gap

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2 o about 31 g 6 04 8

MPK 7N05V 3/00, 3/40

F24H 3/02, 3/04 of inert gas, in addition, the heater is equipped with current leads connected to

current collector flanges.

In addition, the spiral can be made in the form of two connected spirals of different radii of curvature, placed one in the other.

Additionally, the space between the heat-insulating casing and the heat-releasing channel may be filled with heat-insulating material.

A diagram of the proposed electric gas heater is shown in the figure. The heater contains current leads 1, gas inlet pipe 2, heated gas outlet pipe 3, current-collecting flanges 4, heat-releasing tube spiral 5, heat-insulating casing 6, material 7 with low thermal conductivity, external casing 8, inlet nipple 9 and outlet fitting 10.

The device operates as follows:

An electric current is supplied from current source 1 to current leads 1 connected to current collector flanges 4. In the pipe 2 of the gas inlet gas is supplied from the gas source with the required flow rate. When an electric current passes through a fuel element, which is a tubular spiral 5, heat is released that is used to heat the gas moving along the channel along its inner surface. The gas thus heated is supplied to the consumer through the outlet pipe 3 of the heated gas outlet. The heat absorbed by the external surface of the heat-generating tubular spiral 5 is transferred to neighboring turns of the spiral by additionally heating them, and the material with low thermal conductivity 7 and the heat-insulating casing 6 placed in the external casing 6 prevent the heat flux from spreading outside the heat-insulating casing 6, thereby reducing heat loss. In the case of operation of the device in an explosive atmosphere to prevent contact of this medium with heated sections of the device, a neutral gas for this medium is supplied through the inlet 9, which fills

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the space between the heat-insulating casing 6 and the outer casing 8 and expires through the outlet fitting 10, preventing the penetration of this medium to the heated areas of the device. The degree of heating of the gas moving along the heat-generating channel is regulated by a change in the supplied electric power and / or by a change in the flow rate of the heated gas.

The channel of a curvilinear shape and a variable radius heated by electric energy causes intensive mixing of the wall and inner layers of the moving gas, thereby intensifying the heat exchange between the channel surface and the moving gas, significantly increasing the heating rate and reaching the stationary mode of gas heating at various flows, pressures and speeds currents. The introduction of cold gas into a curved (spiral) channel of a large radius and the outlet of a gas heated during its movement along a curved (spiral) channel of a smaller radius, located inside a spiral of a larger radius, can reduce heat losses due to the inter-turn heat transfer of the spiral channels to each other. The implementation of the fuel element in the form of spirals of variable radius, placed one in the other, can significantly improve heat transfer and reduce heat loss, dimensions and weight of the device, increase its efficiency.

The supply of electric energy to the flanges allows you to increase the area of electrical contact, reducing contact resistance, increase the reliability of the device and reduce heat loss at the contact points.

Placing a heat-releasing element in a heat-insulating casing and filling the internal space with a material with low thermal conductivity significantly reduces heat loss, reduces the heating of the external casing. The gap between the walls of the buildings and the presence of non-combustible (inert) gas in it

allows you to use the device in explosive and fire hazardous conditions, to minimize the heating of the outer casing.

An example of a specific implementation:

Consider a special case of heating gas / air / to a temperature of 300 ° C with the following initial parameters: pressure 0.8 MPa, flow rate 90 nm / h, temperature and the ratio of the diameters of the external and internal heat-releasing tubular spirals, as 2: 1.

They include a compressor connected to the device and a power supply regulated by electric power. Set the necessary initial gas parameters at the inlet to the pipe of the external spiral of the device and bring the consumed electric power to 10 kW. With these input parameters, heating of the gas moving along the spiral heat-generating channel is carried out for 15 seconds, while the external case is heated in a stationary mode no higher than 40 ° С. Heated air is thus supplied to the consumer, for example, in a device for coating in a gas-dynamic manner. To stop the supply of heated gas to the consumer, turn off the source of electrical power, then the compressor.

By changing the gas input parameters and the supplied electric power, the device allows heating the gas moving through the heat-generating spiral channel from the initial inlet temperature to the outlet temperature equal to / 1000 300 / С. The maximum gas flow rate and gas pressure are determined only by the cross-section, wall thickness, and heat-generating material tubular spiral and consumer device.

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Claims (3)

1. An electric gas heater, including a heat-conducting channel in the form of a conductive pipe, characterized in that the pipe is rolled into a spiral with a variable radius of curvature, placed in a heat-insulating casing and provided at the ends with current-disconnecting flanges, with which it is attached to a heat-insulating casing and heating gas inlets and the outlet of the heated gas, while the insulating casing is placed in the outer casing with a gap between their walls and is equipped with inlet and outlet fittings for introducing inert gas into the gap, in addition a heater provided with tokovodami connected to tokorazemnymi flanges. 2. The electric gas heater according to claim 1, characterized in that the spiral is made in the form of two connected spirals of different radius of curvature, placed one in the other. 3. The electric gas heater according to claim 1, characterized in that the space between the heat-insulating casing and the heat-releasing channel is filled with heat-insulating material.