RU2708175C1 - Air heater - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: invention relates to devices for high-temperature air heating and can be used in power, petrochemical, gas processing and other industries, as well as for heating production and domestic facilities. Air heater comprises shell ring with air inlet and outlet pipes, furnace located inside shell ring in form of cylindrical barrel with burner device and chimney, as well as tubes connected to ends of collectors, furnace barrel wall is formed by tubes closely spaced towards each other; at that, annular cavity created between shell ring and tubes is equipped on the burner device side with collector for secondary air supply, and on the opposite side – with exhaust pipe coaxially located with furnace chimney.

EFFECT: invention shall increase efficiency of air heating with simplification of design and manufacturing technology.

5 cl, 4 dwg

Description

The invention relates to devices for high-temperature heating of air and can be used in energy, petrochemical, gas processing and other industries, as well as for heating industrial and domestic premises.

A tubular heater is known, comprising a housing, a heat pipe located inside the housing, an intermediate liquid coolant and a tubing coil for passing the heated medium located between the housing and the heat pipe, the heat pipe and the housing are made in the form of straight cylinders and have one common axis, concentrically with it houses a cylindrical secondary emitter with a streamlined body inserted into it (patent RU No. 2662018, F22B 7/00, 2017).

The disadvantages of the known heater are the use of an intermediate coolant, the lack of environmental protection from surfaces heated to a high temperature, the inability to use secondary air flows.

The closest technical solution for the totality of features to the claimed object and adopted for the prototype is an air heater containing a shell with nozzles for air inlet and outlet, a furnace with a burner and a chimney located inside the shell, a convective part made in the form of tubes connected to the ends of the collectors wherein the furnace is made in the form of a cylindrical glass, the tubes of the convection part are located around the furnace parallel to the cylindrical surface of the furnace in a checkerboard pattern moreover, the incoming manifold, mounted with the possibility of connecting to the furnace and located opposite the burner device, is a sector with an obtuse angle, the output collector connected to the chimney and located on the same side is an isolated sector with an acute angle, while the device equipped with an intermediate manifold located opposite, and transverse partitions are installed between the shell and the furnace (patent RU No. 2296269, F23L 15/04, 2005).

The disadvantages of the known air heater are the inability to use secondary air flows, the complexity of manufacture, the fast clogging of the inner surface of the pipes due to the fact that flue gases, which are the heating coolant, pass through the pipe space, the lack of environmental protection from surfaces heated to high temperature.

The problem to which the claimed invention is directed, is to eliminate these drawbacks, increasing the efficiency of heating the air with a significant simplification of the design and manufacturing technology.

The problem is solved due to the fact that the wall of the cylindrical glass of the furnace is formed by tubes close to each other, while the annular cavity created between the casing and the tubes is equipped with a collector for supplying secondary air from the side of the burner device and, on the opposite side, with an exhaust pipe, coaxially located with a chimney firebox.

The essence of the invention is illustrated by graphic materials, where: in FIG. 1 shows an air heater, a longitudinal section; in FIG. 2 is an isometric view of the furnace; FIG. 3 and 4 - embodiments of the furnace glass, section AA in FIG. one.

The air heater (Fig. 1) contains a shell 1 with a pipe 2 for supplying heated air and a pipe 3 for removing heated air, a furnace 4, which includes a cylindrical glass 5, the wall of which is formed from tubes located close to each other in a row (Fig. 3 ) or in two rows (Fig. 4) connected to the ends of the collectors 6 and 7 (Fig. 2) for supplying heated air and for removing heated air. In this case, the tubes in the collector 6 are movable to compensate for changes in their length at high temperature. A burner 8 is fixed on the furnace 4 from the side of the collector 7, and a chimney 11 is installed on the side of the collector 6. An annular cavity is created between the shell 1 and the tubes 5, which is equipped with a collector 9 with a pipe 10 for supplying secondary air from the side of the burner device. The exhaust pipe 13 is coaxially located with the chimney 11. A deflector 12 is mounted on the exhaust pipe 13. A gate 14 is installed in the chimney 11 and exhaust pipe 14. The manifold 9 is provided with a protective screen 15 for uniformly supplying secondary air around the circumference from the side of the pipes.

The device operates as follows. The flow of heated air through the pipe 2 is forced to enter the manifold 6, is evenly distributed and flows through the tubes of the cylindrical cup 5, from where it enters the collector 7 and is discharged through the pipe 3. The heating medium is the combustion products of the fuel in the furnace 4. Fuel is supplied to the burner device 8. When burning fuel, high temperature combustion products are formed that pass through the inner cavity of the cup 5 and are removed through the chimney 11. Heat from the flue gases is transferred to the tubes in a radiant and convective manner. The secondary air flow through the pipe 10 enters the manifold 9, passes through the annular cavity formed between the shell and the pipes and is discharged through the exhaust pipe 13.

Using gates 14, you can adjust the draft, as well as to control the flow of air and flue gases.

The air heater can be used both for heating industrial and domestic premises, and in industry.

When the premises are heated, the secondary air will be the indoor air, and when the heater is used in power plants, the secondary air will be the air that completed the work.

In the proposed technical solution, the tubes of the glass wall can be positioned with a gap of no more than 3 mm, while there will partially be a place for overflow (mass transfer) or flue gases from the furnace cavity to the cavity formed between the shell and the tubes (into the secondary air cavity), or secondary air from the specified cavity into the cavity of the furnace. The flow pattern will depend on the amount of thrust in the pipes 11 and 13. Where there is more thrust (less static pressure), the flow will be directed there. Moreover, it is possible to install one or another overflow gate by changing the parameters in the pipes 11 and 13. From the point of view of the influence on the heat transfer process, this element will be present, since, firstly, it is controllable, and, secondly, it is possible to maintain output parameters by Heated air by the combustion process in the furnace. On the other hand, the presence of this constructive solution allows to provide many positive characteristics of the air heater.

When used as secondary air from the environment, the collector 9 is in the form of an annular gap formed by a shell and a protective screen (without pipe 10). At the same time, to prevent the ingress of foreign objects into the cavity of the heat exchanger, a mesh is installed on the slot.

One of the industries in which this device is used in industry is gas turbine plants. An example is a gas turbine installation for processing associated petroleum gas into electricity (patent RU No. 2482302, F02C 3/22, 2013). This air heater will be a heat exchanger-regenerator. It heats up the compressed air received from the compressor, then the heated air is sent to the turbine. Secondary will be called the exhaust air in the turbine, which again returns to the air heater (to pipe 10).

If it is necessary to reduce the overall dimensions of the air heater or increase the area of heat transfer, an embodiment of the furnace glass is possible with pipes staggered (Fig. 4).

Thus, the claimed design of the air heater allows you to solve all the tasks, thereby increasing the efficiency of heating the air.

Claims (5)

1. An air heater containing a casing with air inlet and outlet pipes, a fire chamber located inside the casing in the form of a cylindrical glass with a burner and a chimney, as well as pipes connected to the ends of the collectors, characterized in that the wall of the furnace glass is formed by pipes closely spaced to each other, while the annular cavity created between the shell and the tubes is provided with a collector for supplying secondary air from the side of the burner device, and exhaust pipes on the opposite side Oh, located outside the chimney of the furnace. 2. An air heater according to claim 1, characterized in that gates are installed in the chimney and exhaust pipes. 3. The air heater according to claim 1, characterized in that the manifold for supplying secondary air from the side of the tubes is equipped with a protective screen. 4. The air heater according to claim 1, characterized in that the glass tubes are staggered. 5. The air heater according to claim 1, characterized in that the secondary air collector is made in the form of an annular gap between the shell and the protective screen, while the gap is provided with a mesh.

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