SU1211574A1 - Recuperator for heating and heat-treating furnaces - Google Patents

Description

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The invention relates to devices for heating air that goes to the combustion of fuel and heating and thermal furnaces, and can be used in metallurgical and other industries.

The aim of the invention is to increase the efficiency of use of the heat exchanger.

FIG. 1 shows a heat exchanger section; in fig. 2 shows section A-A in FIG. one; in fig. 3 is the same as the embodiment.

The recuperator contains a housing with a duct-feeding cavity 1 and a heat-exchange cavity 2, bounded by a heat transfer wall 3. Pipe A serves for supplying air, and a hot air collection manifold serves for exhausting air (Fig. 2).

The air supply and heat exchange cavities are separated by chutes 6, for example, arcuate, installed with a gap 7 relative to each other. These gaps between the side walls of a series of installed chutes form parallel solid slots for the passage of air from the air supply cavity to the heat exchange one.

The gutters communicate with the hot air collector and are located at the bottoms 8 to the air-passing cavity. At the heat transfer station C, there are fins 9, which are pa. laid coaxially to the grooves and recessed into their internal cavity 10 to a depth equal to 0.2-0.6 of the height of the groove

To eliminate the occurrence of stagnant zones near the fins on the heat-transmitting wall and increase the uniformity of its temperature, the ribs can be mounted with a gap 11 relative to the heat transfer wall.

To reduce heat loss, the chute can be made double (triple, etc.), i.e. located one above the other with the formation of a thick gap between them.

To raise the temperature of air preheating, the hot air collector can be connected to air supply 17, with a cavity next to it along the air path of a similar recuperator (Fig. 3). Outside, the rectifier has thermal insulation (not shown).

The heat exchanger works in a sensible way.

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The bent gases pass through a gas duct (not shown), washing the heat transfer wall. The cold air through the pipe 4 enters the air supply cavity 1 and through the slit nozzles 7 flows onto the heat transfer wall 3. Turning around the fins 9 and heating, the air flows along the grooves 6. Hot air enters the collector 5 and is discharged from the heat exchanger.

The height of the rib is chosen so that it is sunk into the internal cavity of the chute to a depth of 0.2 - b, 6 its height. The rib is a partition between the air flows flowing from the nozzles on both sides of the chute.

When this value is less than 0.2, the septum effect in the gutter is lost, and the heat exchange surface decreases. It is impractical to take this value more than 0.6, since the aerodynamic drag in the chute increases, which reduces the efficiency of the heat exchanger.

Installation with a gap relative to each other of the grooves located by the bottoms to the air supply cavity completely eliminates the curvature of the trajectories of the air jets by the flow of the heated heated air and the mixing of cold air with the heated air, and also reduces the aerodynamic drag.

In this case, the shape of the entrance slots formed by the side walls of the adjacent grooves facilitates the entry of cold air into the heat exchange cavity, and their narrowing in the direction of air flow increases its speed at the moment of impact on the heat transfer wall, and, consequently, the intensity of heat exchange.

Installing coaxially to the grooves of the ribs embedded in them on the heat transfer wall increases the total heating surface washed by the air (cold), increases the temperature uniformity of the heat transfer wall and contributes to the separation of air flowing out of the nozzles on both sides of the gutter, avoids their collision and creates the possibility of multiple circulation of heated air near the heat transfer wall.

The proposed constructive implementation of the heat exchanger allows to increase its efficiency.

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FIG. 2

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Compiled by V. Berbenev tehred m. Parotsay Proofreader V. Sinitska

Order 632/45

   Subscription VNIIPI USSR State Committee

for inventions and discoveries P035, Moscow, Zh-35, Raushsk nab, d. 4/5

Branch PgaT Patent. Uzhgorod, ulGproektn1 T

Claims (1)

A RECOVERER FOR HEATING AND THERMAL FURNACES, comprising a housing with an air supply and heat exchange cavities, a heat transfer wall with fins and a hot air collector, characterized in that, in order to increase the efficiency of the use of the recuperator, it is equipped with gutters arranged with a gap relative to each other, located bottoms to the air supply cavity, and the side walls of adjacent grooves form nozzles, while the ribs are mounted coaxially with the grooves and are recessed into them to a depth of 0.2-0.6 ba. n * SS SU ..,. 1211574> 1,121