Gas heating of the railway switch – bright, but expensive!

Railroad switches are complex technical devices that are sensitive to environmental conditions. They are made up of a large number of mechanical elements, many of which are movable. In winter snow and ice constantly accumulate between the moving parts, preventing the turnout from fully functioning.

the railway switch

To ensure the smooth operation of the switch, the snow and ice must be removed. This problem was solved by the operational services in different ways at different times. The main method of getting rid of ice and snow cover is manual. However, to solve this problem today, heating of turnouts is used. For this purpose, gas or electricity is usually used.

For gas heating of switches, flare-chamber heaters and flameless infrared burners are used. The flare-chamber heater consists of a heating chamber and an injection burner. The gas-air mixture that leaves the mixer of the injection burner is diverted into the combustion chamber and burns, providing uniform heating of its surface up to 300 ° C.

the railway switch

The elements of the turnout switch are heated due to the thermal conductivity of the screen, thermal radiation from the side surfaces of the screen and the heat of combustion products. Combustion products are discharged through slots into the space between the frame rail and the blade in the direction of the switch shoes. The installation of burners inside the heating chambers excludes the possibility of ignition of combustible products falling on the track from trains. On one turnout switch, 10-14 heaters are installed under the rail base. Gas consumption for one turnout is approximately 3 kg / h. The gas supply of the burners is carried out through manifolds connected to the liquefied gas tanks.

In infrared burners, gas burns on a radiating surface (ceramic nozzle) in a thin layer without a visible flame. The burner consists of a cast iron body, a steel diffuser for uniform distribution of the gas-air mixture on the radiating surface, a nozzle, a glow plug, a temperature sensor and devices for attaching the burner to the rail. Up to 20 burners are installed on the switch: 18 – for bottom heating from the side of the rail foot and 2 – for side heating of frame rails. Side heating burners are installed on the neck of the frame rail from the outside. The heating of frame rails up to 50 ° and switch shoes up to 35 °, depending on the ambient temperature and wind strength, occurs in 1.5-2 hours. The consumption of natural gas for one turnout is about 3 kg / h.

It is recommended to use a gas heating system for turnouts on tracks where there is not enough electrical power to heat the turnouts. Gas heating units can operate on both natural gas and liquefied propane. To store this gas, it is necessary to equip underground tanks or group gas cylinder installations.

The disadvantages of gas heating are: the need to address fire safety issues; difficulties in operation with strong skids, when gas burners may not ignite; low resistance of ceramic nozzles to dynamic loads; insufficient heating of the wit in the wrung-out position under severe climatic conditions.

Railway magazine “Railway Supply”

Related:

Electrical heating systems for railway switches

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