SU1726912A1 - Air heater - Google Patents

Abstract

Use: for heat recovery. Objective: increase operational reliability by protecting against low-temperature corrosion. The heating gases pass through the flue, where heat is transferred to the walls (C) of the buildings (K) 4. In K 4, heated air flows through duct 8, which flows through the holes in the last jets to K 4 and heats up. Due to the fact that C boxes 8, parallel to the C K 4 gas flow direction oriented, are made solid, they cool worse than C K 4, to which air jets flow. This prevents overcooling of these solid С and, accordingly, the possibility of low-temperature corrosion. 1 h. n. f-ly, 5 ill.

Description

L

-one

b

Lymypypy gases

-I

IG

in 12 cpus-.

The invention relates to heat exchange engineering and can be used in fuel-burning devices and ventilation and heat recovery systems.

Known selected as an analogue air heater, comprising a housing with a bundle of vertical pipes placed inside it, divided into groups, and box-shaped air distributors.

The disadvantages of the analogue include the increased intensity and complexity of manufacturing, the need to replace the entire heat exchanger, rather than individual modules, in case of corrosion of part of it.

The closest in technical essence to the present invention is a jet recuperator comprising a distribution chamber with gas outlets, each of which is provided with a nozzle directed toward the heat exchange surface.

The disadvantage of the prototype is low reliability when operating in aggressive gases. I This is due to the high intensity of heat exchange on the locally blown streams coming out of the gas outlets, areas of the heat exchange surface. It is in these areas that the acid phase falls out (for example, sulfuric acid) and intense low-temperature corrosion proceeds.

The aim of the invention is to increase operational reliability by protecting against low-temperature corrosion.

This goal is achieved by the fact that the air heater contains air outlets made in the form of horizontal slots, as well as turbulators-mixers made in the form of the lower edges of the air outlets bent toward the casing, and the wall of the box parallel to the wall facing the gas flow shell, made solid.

Comparative analysis with the prototype shows that the proposed device differs from the prototype by the presence of slotted air outlets, turbulators made in the form of the lower edges of the openings bent toward the body, and a solid box wall that is parallel to the gas flow and solid wall of the hull on the outside of its finning.

FIG. 1 shows schematically the proposed air heater; in fig. 2 shows section A-A in FIG. one; in fig. 3 is a view B in FIG. one; in fig. 4 is a diagram of the input section of the junction box; in fig.

5 shows the node I in FIG. 1 (section of the wall of the junction box with air outlets).

The air heater contains a flue 1, a vertical body 2 inside which are placed separate box-shaped distribution boxes 8 with air outlets 9, turbulators- mixers 10, a solid wall of the body 4,

0 in which finning 5 is made from the outside. Branch pipes 6 and 7 of cold and hot air supply are connected to the end walls.

Near the air outlets 9

5 there are located turbulators-mixers 10. Between the wall of the box 3 and the air distribution box 8 there is a space 11 for the passage of heated air.

The air heater works as follows.

The hot flue gases enter the enclosure 1 and pass through the space 12 between the vertical enclosures 2 where they are cooled. The fins 5 on the side walls

5 housing 4 contributes to a more intense heat transfer from the hot flue gases to the heated air.

The cold air through the pipe 6 enters the air distributors 8, from which through the air outlets 9 passes into the space 11, where it is heated and discharged through the pipe 7. In the space 11, the air rises from the bottom up, while its speed is variable. AT

5 of the lower part, where a small amount of cold air enters, the speed is small, then, as the next portions of air are supplied through the holes located along the height of the air distributor 9,

0 its speed increases, and the air temperature also increases.

Turbulisator-mixers 10 provide mixing of cold air entering through openings 9 with heated air, and also prevent local side washing of body 4 with cold air. Tubbulizers-mixers are made in the form of poorly streamlined plates that turbulize air flow and

0 thereby ensure its mixing.

The turbulators-mixers are made in the form of slotted plates, bent at an angle of 20-40 ° to the side wall of the air distributor 8. The end of the plates at a distance of three millimeters from the edge is bent under

an angle of 70-50 ° to the plane of the streamlined plates, thus the bent end of the plate is located horizontally across the upflow

of air. Cross-flushing plates and causes turbulence of the air flow. The turbulators-mixers can also be made in the form of a series of parallel curved plates assembled with a gap forming the slots 9.

The design of box-type air distributors 2 allows the specified temperature values of the walls of the housing 4 to be provided, at which low temperature corrosion does not occur. Thus, this makes it possible to optimize the operation of heat transfer surfaces, increase their durability, and increase the reliability of the air preheater.

Claims (2)

Claim 1. Air heater comprising a vertical body disposed in the duct and located inside the latter Aa 1 -I FIG. 2 a junction box with air outlet openings directed to the housing walls, provided with each turbulator-mixer, each duct wall parallel to one of the housing walls, and one of the latter is oriented towards the gas flow, in order to increase operational reliability by protecting from low-temperature corrosion, the said air outlets are made in the form of horizontal slots, and the turbulators-mixers - in the form of the lower edges bent to the side of the case The duct, while the wall of the duct, parallel to the gas wall oriented toward the gas flow, is made solid. 2. Air heater according to claim 1, characterized in that the fins are made on the outside of the case. G1 Cold air. FIG. 3