CN202118939U - Air preheater - Google Patents

Abstract

The utility model relates to an air preheater which uses the waste heat gas of a bell furnace to preheat the air. A number of heat exchange tubes are evenly installed between the two partitions. Air outlets and inlets are arranged on one side of the shell. The flue gas circulates between the two partitions. There is another partition in the middle of the partition on one side, separating the air inlet and outlet. Since the general seamless steel pipe is used as the heat exchange pipe, no welding is required, the structure of the air preheater is simple, the installation is convenient, the production cost is reduced, and the service life is improved. There are spiral heat-resistant steel sheets inside the heat exchange tubes, so that the air can fully walk along the tube walls, absorb heat to the maximum extent, and raise its temperature. Or there are spiral fins welded on the outside of the tube wall to increase the heat transfer area and fully improve the heat transfer effect.

Description

Air preheater

Technical field:

The utility model relates to an air heater, in particular to a device for preheating air by utilizing waste heat gas of a bell furnace.

Background technique:

In recent years, with the increasing market demand for bright annealed ferrous and non-ferrous metal plates and strips, these plates and strips are often delivered in the form of coils in the production process, and their heat treatment has long been mainly dependent on gas Bell furnace, when the high-speed burner used in the bell furnace is burned, the excess air and gas are mixed through the air and gas ratio adjustment system. Generally, the oxygen content (volume fraction) in the mixed gas is controlled at 3%-5%. achieve complete combustion. If the temperature of the fed air is higher, the combustion efficiency of the gas and the combustion intensity of the burner will be better, and the combustion of the gas will be safer. At present, the air heating method of the bell furnace mostly adopts the high temperature generated by the bell furnace during the heating process. The flue gas is heated by heat transfer. This heating method is in line with the industrial policy of building a conservation-minded society advocated by the country, and at the same time avoids a large amount of high-temperature flue gas in the bell furnace being directly discharged into the air, causing greenhouse effect and polluting the environment. For example, the Chinese utility model patent CN 2432221Y discloses a combustion-supporting air preheater for bell annealing furnaces, which includes a shell with flue gas inlet and outlet and air inlet and outlet. The annular channel of the air channel constitutes an air channel, and its upper and lower ends are respectively connected to the air inlet and outlet; the inner cavity of the inner sleeve and the annular cavity between the outer sleeve and the shell form a smoke channel, and its lower and upper ends are respectively connected to the inlet and outlet of the smoke; the inner and outer sleeves One of the two is a round tube and the other is a finned tube, or both are finned tubes. Although this technology can perform heat exchange in a limited shell cavity, since the inner and outer tubes are all finned tubes, in order to make the inner cavity have a larger heat exchange area, several finned tubes must be welded together. It has the disadvantages of complex structure, cumbersome processing and uneven heating. the

Utility model content:

The purpose of the utility model is to provide a novel air preheater with simple structure and convenient installation.

The utility model is achieved in this way. An air preheater includes a heat exchange tube, a partition and a shell containing heat-insulating materials. The upper and lower sides of the shell are respectively provided with flue gas inlets and outlets. It is characterized in that: There are two baffles inside the shell, several heat exchange tubes are evenly installed between the two baffles, air outlets and inlets are arranged up and down on one side of the shell, and the flue gas There is another partition in the middle of the partition near the air inlet and outlet to separate the air inlet and outlet.

Compared with the prior art, the utility model has the following advantages:

1. Due to the use of general heat-resistant thin-walled heat exchange tubes, the structure is simple, the installation is convenient, the production cost is reduced, and the service life is improved.

2. There are spiral heat-resistant steel sheets in the heat exchange tube, so that the air can fully walk along the tube wall during the walking process, absorb heat to the maximum extent, and make its temperature rise. Or there are spiral fins welded on the outside of the tube wall to increase the heat transfer area, so that the temperature of the air inside the tube can be raised to the maximum, the temperature of the flue gas can be reduced to the maximum, and the heat exchange effect can be fully achieved.

Description of drawings:

Fig. 1 is the structural representation of air preheater described in the utility model

1. Shell 2. Flue gas inlet 3. Insulation material 4. Partition 5. Heat exchange tube 6. Air outlet 7. Partition A ⒏ Air inlet ⒐ Flue gas outlet

Detailed ways:

The following examples are used to illustrate the utility model, but are not used to limit the scope of the utility model, and all equivalent technical solutions also belong to the category of the utility model, and the patent protection scope of the utility model should be limited by each claim.

It can be seen from Fig. 1 that an air preheater includes a heat exchange tube 5, a separator 4 and a shell 1 containing an insulating material 3, and a flue gas inlet 2 and an outlet are respectively arranged on the upper and lower sides of the shell 1. 9. It is characterized in that there are two baffles 4 inside the shell 1, and several heat exchange tubes 5 are evenly installed between the two baffles 4. An air outlet 6 and an inlet 8 are arranged up and down on one side, and the flue gas circulates between the two partitions 4, and there is another partition A7 in the middle of the partition 4 on the side close to the air inlet 6 and the outlet 8. The air inlet 6 and outlet 8 are separated.

There are spiral fins on the inner wall of the heat exchange tube 5 at the air outlet 6 .

Spiral fins are evenly welded on the outside of the heat exchange tube 5 at the air outlet 6 .

Claims (3)

1. An air preheater, comprising a heat exchange tube (5), a partition (4) and a shell (1) containing an insulating material (3), above and below the shell (1) respectively provided with a flue gas inlet (2) and an outlet (9), characterized in that : There are two partitions (4) in the housing (1), a number of heat exchange tubes (5) are evenly installed between the two partitions (4), and one side of the housing (1) is arranged up and down The air outlet ⑹ and the inlet ⑻, the flue gas circulates between the two partitions ⑷, there is another partition A⑺ in the middle of the partition ⑷ on the side near the air inlet ⑹ and the inlet ⑻, and the air inlet ⑻ Separated from import ⑻. 2. An air preheater according to claim 1, characterized in that there are spiral fins on the inner wall of the heat exchange tube (5) at the air outlet (6). 3. An air preheater according to claim 1 or 2, characterized in that spiral fins are evenly welded on the outside of the heat exchange tube (5) at the air outlet (6).

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