SU941793A1 - Recuperative air heater heat-exchange element - Google Patents

Description

(54) HEAT EXCHANGE ELEMENT OF REMOVABLE AIR HEATER

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The invention relates to heat exchange technology and can be used in thermal installations.

Known heat exchange elements of the recuperative air heater, made in the form of inner and outer tubes, the last of which is plugged from the end using the bottom in the form of a hemisphere, and located from the output end of the inner tube with a given gap 1.

A disadvantage of the known heat exchanging element is the difficulty of manufacturing associated with the configuration of the bottom in the form of a hemisphere.

Closest to the invention is a heat exchange element, made in the form of inner and outer tubes, the latter of which is plugged from the end using a flat bottom in the form of a plate, and located from the outlet end of the inner pipe with a gap of 2.

The disadvantage of this heat exchanger element is the lack of reliability associated with low corrosion protection under operating conditions in aluminum smelting furnaces, the exhaust gases of which contain particles of salts used as fluxes during smelting.

The purpose of the invention is to increase reliability by improving corrosion protection.

In order to achieve this goal, the bottom is introduced into the cavity of the outer tube at a distance of 0.5-1.0 times its diameter, and the gap between the bottom and the outlet, 0, of the inner tube is 0.5-0.75 of the diameter of the latter.

Due to this arrangement, the most vulnerable place, namely the junction of the bottom and wall of the outer pipe, is protected from the influence of the corrosive environment, since in the cavity under the bottom during the work a garnish is created that prevents the corrosive action of the exhaust gases.

FIG. 1 shows an air heater mounted from heat exchange elements 20, general view; in fig. 2 - bottom part (B zone of the bottom) of the heat exchange element.

The heat exchange elements 1 contain the inner 2 and outer 3 pipe, and the pipe 3 is plugged from the end 4 using

the bottom 5 located from the outlet end 6 of the inner pipe 2 with a gap, the value of which is 0.5-0.75 of the diameter of the pipe 2. The bottom 5 is introduced into the cavity of the pipe 3 for a distance equal to 0.5-1.0 of its diameter. The heat exchange elements 1 are connected to the air-supplying 7 and the air-removing 8 collectors and are located in the gas duct 9, equipped with the gas supplying 10 and the gas-exhausting II branch pipes.

The work of the heat exchange element is as follows.

The air enters through the manifold 7 into the inner pipe 9, passes through it, enters the space between pipes 2 and 3 and the heated enters the collector 8. Exhaust gases through the pipe 10 enters the flue 9, wash the outer surface of the pipe 3, give off heat to the air and the cooled ones are removed through the pipe 11. During operation, a garnissage is formed in the cavity between the bottom 5 and the end face 4 of the pipe 3, preventing corrosion of the joint between the bottom 5 and the pipe 3.

The use of the described heat exchange element improves its reliability by protecting against corrosion.

Claims (2)

1. Tebenkov B.P. Recuperators for industrial furnaces. M., “Metallurgists, 1967, p. 167, fig. 99 2. Lemlekh I.M. High-temperature air heating in ferrous metallurgy. M., Metallurgizdat, 1963, p. 194, fig. VI-II.