CN202016973U - A coke oven that efficiently recovers waste gas heat - Google Patents

Abstract

The utility model relates to a coke oven for recovering the heat of the waste gas of the coke oven in the field of metallurgical coking, which comprises a combustion chamber vertical flue, a waste gas channel, a radiation chamber, a double-pipe type heat exchange device, an air distribution chamber and a waste gas small flue channel; the double-tube heat exchange device is arranged in the radiation chamber and is of a sleeve type structure consisting of an inner tube and an outer tube, the lower part of the inner tube is an air inlet, the top end of the inner tube is communicated with the outer tube, and the upper part of the outer tube is of an end enclosure structure; the annular channel between the inner tube and the outer tube is a down channel of the air after heat exchange; a plurality of sections of air feeding devices are arranged in the vertical flue of the combustion chamber, and a plurality of air introducing ports with different heights are arranged on the plurality of sections of air feeding devices in the height direction of the vertical flue. The utility model has the advantages that: the furnace body structure is small in size, the effective combustion time utilization rate of the combustion chamber is high, and the heat recovery efficiency is high.

Description

A coke oven that efficiently recovers waste gas heat

technical field

The utility model relates to the field of metallurgy and coking, in particular to a coke oven body structure.

Background technique

In the prior art, the thermal economy of the coke oven has been improved by using waste heat to preheat the combustion air through heat exchange and heat storage systems. With the development of coke oven technology, it is found that the regenerative system is more superior than the heat exchange system in terms of thermal engineering. On the one hand, due to the size limitation of the heat exchange device. On the other hand, due to the heat exchange system, only ceramic materials with poor thermal conductivity could be used at that time. Compared with the heat-exchange coke oven, the regenerative coke oven only needs a small increase in the volume of the heat exchange body to improve the heat recovery efficiency, and it can be easily built with conventional refractory materials.

However, the disadvantages of the regenerative coke oven are: 1) due to the improvement of thermal efficiency, the structure of the furnace body must be high, large and complicated. 2) To cooperate with heat exchange, gas-air-gas exchange must be carried out, that is, there must be an exchange time. Therefore the effective burning time of its single fire path has only utilized 47%.

Compared with the regenerative coke oven, the heat exchange coke oven has the following advantages: heating does not require regular reversing, and the combustion adjustment is more accurate; it can effectively improve the combustion time; Direction, resulting in the problem of low utilization of effective combustion time; the oxygen content in the exhaust gas can easily reach about 2%. Such a low exhaust gas oxygen content cannot be achieved under the current design and construction status of coke ovens using regenerative heating systems.

Contents of the invention

The purpose of the utility model is to provide a coke oven for recovering the heat of coke oven waste gas with small furnace body structure, high utilization rate of effective combustion time of the combustion chamber, and high heat recovery efficiency.

In order to achieve the above object, the utility model is realized through the following technical solutions:

A coke oven for efficiently recovering waste gas heat, including a combustion chamber vertical flue, a waste gas passage, a radiation chamber, a double-pipe heat exchange device, an air distribution chamber, and a small flue passage for waste gas;

The lower part of the exhaust gas channel is the radiation chamber, and the double-pipe heat exchange device is installed in the radiation chamber. The double-pipe heat exchange device consists of an inner pipe and an outer pipe to form a casing structure. The lower part of the inner pipe is the air inlet, and the top of the inner pipe communicates with the outer pipe. , the upper part of the outer tube is a head structure; the annular channel between the inner tube and the outer tube is the downward channel of the air after heat exchange;

The lower part of the double-pipe heat exchange device is an air distribution chamber, and the downward passage of the air after heat exchange is connected with the air distribution chamber; the air distribution chamber is connected with the combustion chamber vertical fire channel;

The bottom of the radiation chamber communicates with the small waste gas flue in the lower part of the carbonization chamber through the small waste gas flue channel.

A multi-stage air supply device is provided in the vertical fire passage of the combustion chamber. The multi-stage air supply device is provided with multiple air inlets of different heights in the height direction of the vertical fire passage; the coke oven gas nozzle is arranged at the bottom of the vertical fire passage. The upper part of the fire channel communicates with the waste gas channel through a spanning hole; a partition wall is arranged between the standing fire channel and the waste gas channel.

The combustion chamber vertical fire passage, multi-stage air supply device, waste gas passage, radiation chamber, double-pipe heat exchange device, air distribution chamber, and waste gas small flue passage constitute a combustion and heat exchange system. The system is divided into two groups. In the longitudinal direction of the coke oven, it is divided into two independent systems by the transverse partition wall of the combustion chamber.

The small waste gas flue is connected with the high-temperature waste gas branch flue located on the coke side; the high-temperature waste gas branch flue on the coke side is connected with the coal preheating system through a connecting channel.

Compared with the prior art, the beneficial effects of the utility model are:

1. The height of the coke oven body is greatly reduced, which is conducive to reducing the refractory materials used for the masonry of the coke oven body.

2. The height of the coke oven body is greatly reduced, which is conducive to the reduction of the height and weight of the coke oven machinery matched with it, thereby reducing investment.

3. Due to the cancellation of the reversing device, the original switch device of the coke oven in the regenerator can be canceled, thereby reducing investment.

4. Since the heat exchange of the coke oven of the utility model does not require reversing, the effective combustion time of a single flue channel can be increased from a 47% utilization rate of the regenerative coke oven to a 98% utilization rate. Interrupt for 1 minute every hour, which is used for the removal of carbon deposits in the lower nozzle of the coke oven gas.

5. The coke oven is supplied with air in multiple stages in the high direction, and the air in each stage can be adjusted. It is beneficial to reduce the intensity of coke oven gas combustion; at the same time, a double-pipe heat exchange device is adopted, so that the exhaust gas does not contact with the air, thereby ensuring that the oxygen content in the exhaust gas is about 2%. These two points are conducive to reducing the NOx content in the exhaust gas, and are more conducive to environmental protection.

6. This coke oven uses two stages to recover the heat of the exhaust gas. Compared with the conventional regenerative coke oven, which directly exhausts the exhaust gas into the chimney, it has a better heat recovery rate and is conducive to energy saving and environmental protection.

Description of drawings

Fig. 1 is the coke oven furnace body layout diagram of the utility model;

Fig. 2 is a longitudinal sectional view of the combustion chamber of the coke oven body of the present invention;

Fig. 3 is a structural diagram of a double-pipe heat exchange device;

Fig. 4 is a system diagram of recovering exhaust gas heat;

Fig. 5 is a diagram of the gas supply system inside the coke oven body.

In the figure: a-combustion chamber b-carbonization chamber c-furnace top d-coal charging hole e-rising pipe hole 1-double pipe heat exchange device 2-air distribution chamber 3-radiation chamber 4-three-stage air supply device 5-horizontal crossing hole 6-waste gas channel 7-small exhaust gas channel 8-small exhaust gas channel 9-gas nozzle 10-transverse partition wall of combustion chamber 11-flame passage 12-inner pipe 13-outer pipe 14-sealing Head structure 15-air inlet 16-air outlet after heat exchange

Detailed ways

The furnace body structure and waste gas heat recovery process of the present utility model will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, a coke oven includes a combustion chamber a and a carbonization chamber b. The coal used for coking is loaded into the carbonization chamber b through the coal charging hole d on the roof c, and the heat is provided by the combustion chamber a arranged alternately with the carbonization chamber b. Furnace coal is smelted into coke, and the raw gas generated is discharged from the rising pipe hole e at the top of the furnace into the gas recovery system.

As shown in Figure 2, the coke oven combustion chamber includes a combustion chamber vertical fire channel 11, a multi-stage air supply device 4, an exhaust gas channel 6, a radiation chamber 3, a double-pipe heat exchange device 1, an air distribution chamber 2, and a small exhaust gas flue channel 7 , forming a combustion and heat exchange system, the combustion and heat exchange system is divided into two groups, in the longitudinal direction of the coke oven, the above-mentioned combustion and heat exchange system is divided into two independent systems by the transverse partition wall 10 of the combustion chamber.

A multi-stage air supply device 4 is provided in the vertical fire passage of the combustion chamber, and the multi-stage air supply device 4 is provided with multiple air outlets of different heights in the height direction of the vertical fire passage 11; a coke oven gas nozzle is provided at the bottom of the vertical fire passage 9. The upper part of the fire passage 11 of the combustion chamber communicates with the waste gas passage 6 through the spanning hole 5; a partition wall is provided between the fire passage 11 and the waste gas passage 6.

As shown in Figure 3, the lower part of the waste gas channel 6 is the radiation chamber 3, and the radiation chamber 3 is provided with a double-pipe heat exchange device 1. The double-pipe heat exchange device 1 is composed of an inner pipe 12 and an outer pipe 13. The lower part of 12 is the air inlet 15, the top of the inner pipe 12 communicates with the outer pipe 13, and the upper part of the outer pipe 13 is a head structure 14; the annular passage between the inner pipe 12 and the outer pipe 13 is the downward passage of the air after heat exchange.

As shown in Figure 2, the lower part of the double-pipe heat exchange device 1 is the air distribution chamber 2, and the downward passage of the air after heat exchange communicates with the air distribution chamber 2; connected.

The bottom of the radiation chamber 3 communicates with the small waste gas flue 8 at the lower part of the carbonization chamber through the small waste gas flue channel 7. The small waste gas flue 8 is connected to the high-temperature waste gas distribution flue on the coke side of the coke oven. connected to the preheating system.

See Fig. 4, Fig. 5, adopt the method for recovering waste gas heat of described coke oven, the steps are as follows:

1) The air at a room temperature of 20°C goes up through the inner tube of the double-tube heat exchange device 1 to the end of the outer tube and turns back to exchange heat with the hot exhaust gas in the radiation chamber 3 to generate hot air. The temperature of the hot air is 450°C;

2) The hot air at 450°C enters the air distribution chamber 2, enters the multi-stage air supply device 4 through the flow regulator in the air distribution chamber, and the air is supplied in multiple stages in the vertical fire channel 11 of the combustion chamber; see Figure 5, each stage of air Can be adjusted individually;

3) The coke oven gas is sprayed into the bottom of the combustion chamber vertical flue 11 by the gas nozzle 9, mixed with hot air in stages in the vertical flue 11, and combusted to produce high-temperature waste gas at 1300°C;

4) 1300°C high-temperature exhaust gas rises to the top of the vertical fire passage 11 and enters the waste gas passage 6 through the transverse crossing hole 4, and then descends in the waste gas passage and enters the radiation chamber 3; in the radiation chamber, the 1300°C high-temperature exhaust gas and the double-pipe heat exchange Device 1 conducts the first stage of heat exchange, preheats the air, and reduces the temperature of high-temperature exhaust gas to 850°C;

5) The high-temperature waste gas at 850°C enters the small waste gas flue 8 at the bottom of the carbonization chamber through the small waste gas flue channel 7 after completing the first-stage heat exchange, and then enters the high-temperature waste gas distribution flue on the coke side;

6) The 850°C high-temperature waste gas derived from the high-temperature waste gas branch flue on the coke side is mixed with the added 140°C circulating gas in the mixing chamber of the coal preheating system to cool the high-temperature waste gas to 560°C; After the appropriate temperature, the waste gas enters the preheater to dry and preheat the coal to realize the second stage of heat exchange. After heat exchange, the temperature of the waste gas drops to 100°C, and then it is discharged into the atmosphere. So far, the process of recovering the heat of exhaust gas in the second stage is completed.

Claims (4)

1. the coke oven of a high efficiente callback waste-gas heat is characterized in that, comprises combustion chamber flue, flue, radiation chamber, double hose heat-exchanger rig, air chamber, waste gas bottom flue passage;

The flue bottom is a radiation chamber, and the double hose heat-exchanger rig is arranged in the radiation chamber, and the double hose heat-exchanger rig is formed sleeve type structure by interior pipe, outer tube, and interior pipe bottom is a gas inlet, and interior pipe top communicates with outer tube, and outer tube top is end enclosure structure; Circular channel between interior pipe and the outer tube is the down going channel of air after the heat exchange;

Double hose heat-exchanger rig bottom is the air chamber, and the down going channel of air communicates with the air chamber after the heat exchange; The air chamber is connected with the combustion chamber flue;

The radiation chamber bottom is communicated with the waste gas bottom flue of coking chamber bottom by waste gas bottom flue passage.

2. the coke oven of high efficiente callback waste-gas heat according to claim 1 is characterized in that, is provided with the multistage air and infeeds device in the flue of combustion chamber, and the multistage air infeeds device is provided with a plurality of different heights on the flue short transverse air introducing port; The coke-oven gas nozzle is arranged at the flue bottom, and flue top communicates with flue by crossing over the hole; Be provided with partition wall between flue and the flue.

3. the coke oven of high efficiente callback waste-gas heat according to claim 2, it is characterized in that, described combustion chamber flue, multistage air infeed device, flue, radiation chamber, double hose heat-exchanger rig, air chamber, waste gas bottom flue passage, constitute burning and heat-exchange system, this burning and heat-exchange system are divided into two groups, on the coke oven longitudinal direction, be divided into two independently systems by the combustion chamber across bulkhead.

4. the coke oven of high efficiente callback waste-gas heat according to claim 1 and 2 is characterized in that, described waste gas bottom flue divides flue to be connected with the high-temp waste gas that is positioned at coke side; The high-temp waste gas of coke side divides flue to be connected with the coal pre-heating system by connecting passage.

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