SU61899A1 - Water Tube Steam Boiler - Google Patents

Description

The use of waste-heat boilers in metallurgy saves a large amount of fuel and generates electricity due to the heat of the gases leaving the furnaces. For open-hearth furnaces, the installation of waste-heat boilers is necessary not only for the purpose of heat recovery, but also to increase the productivity of the furnaces, since the necessary vacuum in modern pitcher open-hearth furnaces reaches 150 mm of water. Art. at the temperature of leaving w, their gases are about 600 °. Such a vacuum can hardly be achieved with natural steam, since in order to obtain it, it would be necessary to build a chimney up to 200 m high. At the same time, the use of artificial draft is uneconomical, besides, an artificial draft is needed action from special heat-resistant steels or indirectly smoke exhausters with a capacity of up to 600-700 kW per furnace are needed.

When installing the waste heat boiler behind the furnace, it is possible to use normal smoke exhausters, which give a vacuum of up to 300 mm of water. Art. The power of such a smoke exhauster is about 250 kW.

The proposed water-tube waste heat boiler consists of a water heater of boilers and a superheater. Pipes that discharge saturated steam from the boiler drum to the inlet manifold of the superheater are heated with gases that have passed the superheater; they are located in front of a bundle of heating tubes.

FIG. 1 shows a longitudinal vertical section of a water-tube waste heat boiler; in fig. 2-4 are given other sections of the boiler.

The superheater / normal countercurrent type is located in a vertical duct, branched off from the main duct connecting the furnace with the chimney. Behind the superheater there is an underdeveloped bundle of 2 boiling tubes with natural circulation. In the second gas flue 3 there is a strongly developed boiling water heater 4.

JMb. 61899-2 In drum 5, a combined scheme for the separation and purification of steam is used — steam washing, washing out of the foam, and multistage evaporation. The pipes 6, which discharge saturated steam from the drum 5 to the inlet manifold 7 of the superheater /, are located in front of the bundle of heating pipes 2; they are heated with gases that have passed the superheater 1.

The proposed natural-heat recovery boiler does not require special control methods. For its manufacture, a little more metal is required than for recirculating boilers, while the boiler dimensions only slightly exceed the dimensions of any types of boilers with forced circulation.

Subject invention

A water-tube steam waste-heat boiler consisting of a water heater, a bundle of heating pipes with natural circulation and a steam reheater located in front of this beam, characterized in that the pipes that discharge saturated steam from the boiler drum to the steam superheater inlet manifold pipes and are heated by superheater gases.

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FIG. 2

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