Auxiliary combustion device of secondary combustion chamber of rotary kiln

Abstract

The utility model belongs to the technical field of rotary kilns, and particularly discloses an auxiliary combustion device of a secondary combustion chamber of a rotary kiln, which comprises a secondary combustion chamber body, a combustor and a combustion-supporting unit, the combustion-supporting unit comprises a main air pipe and eight branch pipes, the main air pipe is arranged above the combustor and is communicated with an air inducing pipe, the air inducing pipe is communicated to a solid waste fan, and the eight branch pipes are arranged in the secondary combustion chamber body. The main air pipe is annular and annularly surrounds the secondary combustion chamber body, the two ends of each branch pipe are communicated with the main air pipe and the secondary combustion chamber body respectively, each branch pipe downwards and obliquely penetrates through the furnace wall of the secondary combustion chamber body, the main air pipe is connected with an air volume adjusting valve and a flow meter, and each branch pipe is connected with a butterfly valve. Waste gas air is introduced into the main air pipe from the air inducing pipe to form annular air, the annular air is dispersed to the branch pipes and uniformly sprayed into the secondary combustion chamber body, and the annular air forms an air curtain in the space above the spray gun of the combustor, so that the turbulence intensity of smoke in the secondary combustion chamber body is increased, and the combustion efficiency is improved. And meanwhile, a certain wind resistance effect is achieved on flue gas rising in the secondary combustion chamber.

Description

Technical Field

[0001] The utility model relates to the technical field of rotary kilns, in particular to an auxiliary combustion device of a secondary combustion chamber of a rotary kiln. Background Art

[0002] The secondary combustion chamber is an industrial equipment mainly used to treat and destroy harmful substances generated during the incineration process. The working principle of the secondary combustion chamber is to collect the flue gas and blow it into the secondary combustion chamber through wind for further combustion and destruction. In order to ensure that the unburned materials can be completely decomposed and meet the emission requirements, the exhaust gas from the solid waste workshop is usually introduced into the secondary combustion chamber for combustion treatment with the help of a solid waste fan. The secondary combustion chamber is equipped with a burner to assist combustion and a secondary air supply device to ensure that the flue gas is fully in contact with oxygen at high temperature. The temperature in the secondary combustion chamber is usually controlled at above 850°C, and the residence time of the flue gas in the furnace is ensured to be greater than 2 seconds, so that the organic matter in the flue gas can be fully decomposed and incinerated.

[0003] At present, during the combustion operation of the secondary combustion chamber, in order to ensure the full combustion effect as much as possible, the combustion temperature usually needs to reach about 1100℃. However, the heating rate of the secondary combustion chamber is slow. If the temperature needs to be raised to 1100℃ to meet the combustion requirements, a large amount of fuel will be consumed. Therefore, the fuel consumption of the combustion process in the secondary combustion chamber stage is relatively large, and optimization and improvement are urgently needed to control the fuel consumption. Utility Model Content

[0004] The utility model aims to provide an auxiliary combustion device for the secondary combustion chamber of a rotary kiln, so as to solve the problem that during the combustion operation of the existing secondary combustion chamber, the secondary combustion chamber heats up slowly, and a large amount of fuel is consumed to reach the target temperature, resulting in high energy costs.

[0005] To achieve the above-mentioned purpose, the basic scheme provided by the utility model is: an auxiliary combustion device of the secondary combustion chamber body of a rotary kiln, comprising a secondary combustion chamber body, a burner and a combustion-supporting unit, the distance between the burner and the outlet of the secondary combustion chamber body is 6.1-8.1m, the combustion-supporting unit comprises a main air duct and eight branch pipes, the main air duct is arranged above the burner, the main air duct is connected with an induced draft duct, the induced draft duct is connected to a solid waste blower, the main air duct is annular and surrounds the secondary combustion chamber body in a ring shape, the eight branch pipes are evenly spaced, the two ends of each branch pipe are respectively connected with the main air duct and the secondary combustion chamber body, each branch pipe is inclined downward and passes through the furnace wall of the secondary combustion chamber body, the main air duct is connected with an air volume regulating valve and a flow meter, and each branch pipe is connected with a butterfly valve.

[0006] The principle and beneficial effect of the utility model are as follows: the utility model introduces the exhaust gas generated in the solid waste workshop into the induced draft duct through the exhaust gas fan, opens the butterfly valve and the air volume regulating valve, and the exhaust gas wind is introduced into the main air duct from the induced draft duct, forming an annular wind in the main air duct, and the annular wind is dispersed into each branch pipe and evenly sprayed into the secondary combustion chamber body, and the annular wind forms a wind curtain in the space above the spray gun of the burner, thereby increasing the turbulence intensity of the flue gas in the secondary combustion chamber body, thereby helping the spray gun of the burner on the secondary combustion chamber body to fully burn, and evens out the temperature of each point in the secondary combustion chamber body, and at the same time plays a certain role of wind resistance for the rising flue gas in the secondary combustion chamber, further increasing the residence time of the flue gas in the secondary combustion chamber body to ensure full combustion.

[0007] Option 2 is a preferred option of the basic option. The second combustion chamber body is connected to three first thermocouples, and each of the first thermocouples is located above the burner. Three first thermocouples are used to detect the flue gas temperature near the burner. During use, the detection data can be compared with each other for calibration. At the same time, if one of them is damaged, the other first thermocouples can continue to detect, thereby realizing real-time and uninterrupted temperature detection.

[0008] Option three is a preferred option of option two. The three first thermocouples are distributed in a horizontal fan shape around the second combustion chamber body, and the angle between two adjacent first thermocouples is 60°; this facilitates centralized installation and maintenance of the three first thermocouples.

[0009] Option 4 is a preferred option of Option 2. Three second thermocouples are connected to the top of the secondary combustion chamber body. The insertion depth of each of the second thermocouples into the secondary combustion chamber body is 1.3m. By setting the second thermocouples, it is convenient for the operator to monitor the flue gas temperature near the outlet of the top of the secondary combustion chamber, and the effect of maintaining the temperature of the flue gas after combustion can be measured and recorded for analysis. The insertion depth of the second thermocouple can be controlled to prevent the second thermocouple from being too close to the center of the flue gas and being burned and damaged.

[0010] Option 5 is the preferred basic option. The diameter of the main air duct is DN200, and the diameter of the branch pipe is DN80. The exhaust duct introduces exhaust gas into the main air duct to form a large amount of annular wind under the condition of a larger diameter. The annular wind distributed to each branch pipe enters the secondary combustion chamber with a smaller diameter but a faster flow rate to facilitate the formation of a wind curtain.

[0011] Scheme 6, which is the preferred embodiment of Scheme 5, the bottom of the secondary combustion chamber body is connected to two supplementary heat spray guns for spraying low calorific value liquid into the secondary combustion chamber body; by setting the supplementary heat spray gun, the low calorific value liquid is injected into the bottom of the secondary combustion chamber through the supplementary heat spray gun during normal production, so as to control the temperature near the kiln tail of the rotary kiln to prevent coking at the kiln tail of the rotary kiln, and when coking also occurs in the secondary combustion chamber, high-temperature coking is carried out to prevent the rubber block from solidifying at the bottom of the secondary combustion chamber with the help of the low calorific value liquid;

[0012] At the same time, if a new spray gun is used to inject high calorific value fuel into the secondary combustion chamber, the bottom of the secondary combustion chamber can be kept at a high temperature, and then the molten glue can flow smoothly into the water seal scraper.

[0013] Option 7, which is a preferred embodiment of Option 4, is that a thermometer is connected to the furnace wall of the secondary combustion chamber body; by providing the thermometer, it is convenient for operators to observe the temperature in the rotary kiln.

[0014] Option 8, which is a preferred option of Option 6, the depth of each of the supplementary heat spray guns inserted into the secondary combustion chamber body does not exceed 100 mm from the plane of the castable material on the inner wall of the secondary combustion chamber body, thereby preventing the muzzle of the supplementary heat spray gun from being exposed to the residual heat from the kiln tail.

[0015] Solution 9, which is the preferred solution of Solution 5, uses an integrated thermal gas flowmeter. By setting up the flowmeter, it is convenient for the operator to understand the air volume in the main air duct in real time, and then adjust the total air volume in the main air duct through the air volume regulating valve, so that the total air volume is controlled at 1000Nm 2 / h. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an auxiliary combustion device of a secondary combustion chamber of a rotary kiln according to the utility model;

[0017] Figure 2 It is a schematic diagram of the top view of the secondary combustion chamber body in the auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to the utility model;

[0018] Figure 3 The utility model is a structural schematic diagram of a combustion-supporting unit in an auxiliary combustion device of a secondary combustion chamber of a rotary kiln. DETAILED DESCRIPTION

[0019] The utility model is further described in detail below through specific implementation methods:

[0020] The figure marks in the drawings of the specification include: 1. induced draft duct; 2. secondary combustion chamber body; 3. reinforcement ring; 4. working platform frame; 5. main air duct; 6. branch pipe; 7. first thermocouple; 8. second thermocouple; 9. air volume regulating valve; 10. butterfly valve; 11. burner; 12. thermometer; 13. heat supplement spray gun; 14. flow meter; 15. diagonal support rod; 16. rotary kiln; 17. support rod.

[0021] like Figures 1 to 3As shown: an auxiliary combustion device for the secondary combustion chamber of a rotary kiln, comprising a secondary combustion chamber body 2, a burner 11 and a combustion-supporting unit, the inlet of the secondary combustion chamber body 2 is connected to the kiln tail of the rotary kiln 16, the outlet of the secondary combustion chamber body 2 is connected to the boiler, and two supplementary heat spray guns 13 are connected to the bottom of the secondary combustion chamber body 2, close to the kiln tail of the rotary kiln 16. The two supplementary heat spray guns 13 are symmetrically arranged with the secondary combustion chamber body 2 as the center, and the depth of the two supplementary heat spray guns 13 inserted into the secondary combustion chamber body 2 does not exceed 100 mm of the plane of the castable on the inner wall of the secondary combustion chamber body 2. The two supplementary heat spray guns 13 are filled with low calorific value liquid; each supplementary heat spray gun 13 can also use a natural gas spray gun. When using a natural gas spray gun, the natural gas-specific pipe fittings and electrical and instrument materials used need to match the model of the burner 11.

[0022] The burner 11 is fixedly connected to the furnace wall of the secondary combustion chamber body 2. The distance between the burner 11 and the outlet of the secondary combustion chamber body 2 is 6.1-8.1m, so as to ensure that the minimum residence time of the flue gas in the secondary combustion chamber body 2 is not less than 2s. The distance between the spray gun in the burner 11 and the outlet of the secondary combustion chamber body 2 is 11m. A thermometer 12 is connected to a flange on one side of the outer wall of the secondary combustion chamber body 2. Three first thermocouples 7 are arranged on the furnace wall of the secondary combustion chamber body 2. The three first thermocouples 7 are arranged about 1m above the burner 11. The three first thermocouples 7 are distributed in a horizontal fan shape. The angle between the two outermost first thermocouples 7 is 60°, and the angle between two adjacent first thermocouples 7 is 30°.

[0023] The combustion-supporting unit includes a main air duct 5 and eight branch pipes 6. The diameter of the main air duct 5 is DN200, and the diameter of each branch pipe 6 is DN80. An induced draft pipe 1 is connected between the main air duct 5 and the solid waste fan of the solid waste workshop, which is used to introduce exhaust gas into the secondary combustion chamber body 2 for recycling and to support the combustion of fuel. The main air duct 5 is annular, and the main air duct 5 is annularly surrounded on one side of the outer wall of the secondary combustion chamber body 2. One ends of the eight branch pipes 6 are respectively connected to the main air duct 5, and the other ends of the eight branch pipes 6 are respectively fixed through the outer wall of the secondary combustion chamber body 2 and connected to the secondary combustion chamber body 2. Each branch pipe 6 is tilted downward and penetrates the secondary combustion chamber body 2. Each branch pipe 6 is tilted downward by 15° in the direction of the secondary combustion chamber body 2, so that an annular wind curtain is formed after the exhaust gas enters the secondary combustion chamber body 2.

[0024] The main air duct 5 and the branch pipe 6 are flange-connected with an air volume regulating valve 9 and a butterfly valve 10, respectively. The air volume regulating valve 9 is a manual and electric integrated type, and the butterfly valve 10 is a manual butterfly valve. The main air duct 5 is connected with a flow meter 14, and the model of the flow meter 14 is a WTG-RS-DN200CFACtA plug-in integrated thermal flow meter. By observing the measured value of the flow meter 14, the operator adjusts the air volume regulating valve 9 to control the total air volume in the main air duct 5 at 1000Nm 2 / h. The outer wall of the secondary combustion chamber is bolted with a reinforcement ring 3, a work platform frame 4 is provided on one side of the secondary combustion chamber, a support rod 17 is fixedly connected between the work platform frame 4 and the reinforcement ring 3, and the main air duct 5 is overlapped on the support rod 17; the main air duct 5 is connected with an oblique support rod 15, and the free end of the oblique support rod 15 is bolted to the outer wall of the secondary combustion chamber body 2.

[0025] Three second thermocouples 8 are connected to the outlet of the secondary combustion chamber body 2 near the straight section. The three second thermocouples 8 are distributed in a horizontal fan shape, and the angle between two adjacent second thermocouples 8 is 30°. The insertion depth of each second thermocouple 8 into the secondary combustion chamber body 2 is 1.3m.

[0026] The implementation method of this embodiment is as follows: when the device is used, the operator manually opens the butterfly valve 10 on the eight branch pipes 6 and opens the air volume regulating valve 9 on the main air duct 5. The exhaust gas wind led out by the solid waste blower enters the main air duct 5 through the induced draft pipe 1. The exhaust gas wind fills the annular main air duct 5 to form annular wind. The annular wind is dispersed into the eight branch pipes 6 and evenly sprayed into the secondary combustion chamber body 2. Under the condition that the eight branch pipes 6 are inclined, the annular wind forms a wind curtain in the space above the spray gun of the burner 11, thereby increasing the turbulence intensity of the flue gas in the secondary combustion chamber body 2, thereby helping the spray gun of the burner 11 on the secondary combustion chamber body 2 to fully burn and evenly distribute the temperature of each point in the secondary combustion chamber body 2. At the same time, the annular wind also plays a certain role in wind resistance on the rising flue gas, further increasing the residence time of the flue gas in the secondary combustion chamber body 2.

[0027] The above is only an embodiment of the utility model, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An auxiliary combustion device for the secondary combustion chamber of a rotary kiln, characterized in that: The invention comprises a secondary combustion chamber body (2), a burner (11) and a combustion-supporting unit, wherein the distance between the burner (11) and the outlet of the secondary combustion chamber body (2) is 6.1-8.1 m, and the combustion-supporting unit comprises a main air duct (5) and eight branch pipes (6), wherein the main air duct (5) is arranged above the burner (11), the main air duct (5) is connected to an induced draft duct (1), and the induced draft duct (1) is connected to a solid waste blower, the main air duct (5) is annular and surrounds the secondary combustion chamber body (2) in an annular shape, the eight branch pipes (6) are distributed at equal intervals, and the two ends of each branch pipe (6) are respectively connected to the main air duct (5) and the secondary combustion chamber body (2), and each branch pipe (6) is inclined downward and penetrates the furnace wall of the secondary combustion chamber body (2), the main air duct (5) is connected to an air volume regulating valve (9) and a flow meter (14), and each branch pipe (6) is connected to a butterfly valve (10).

2. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 1, characterized in that: The secondary combustion chamber body (2) is connected to three first thermocouples (7), and each of the first thermocouples (7) is located above the burner (11).

3. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 2, characterized in that: The three first thermocouples (7) are distributed in a horizontal fan shape around the secondary combustion chamber body (2), and the angle between two adjacent first thermocouples (7) is 60°.

4. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 2, characterized in that: Three second thermocouples (8) are connected to the top of the secondary combustion chamber body (2), and the insertion depth of each of the second thermocouples (8) into the secondary combustion chamber body (2) is 1.3 m.

5. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 1, characterized in that: The diameter of the main air duct (5) is DN200, and the diameter of the branch pipe (6) is DN80.

6. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 5, characterized in that: The bottom of the secondary combustion chamber body (2) is connected to two heat supplement spray guns (13) for spraying low calorific value liquid into the secondary combustion chamber body (2).

7. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 4, characterized in that: The furnace wall of the secondary combustion chamber body (2) is connected with a thermometer (12).

8. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 6, characterized in that: The depth of each of the supplementary heat spray guns (13) inserted into the secondary combustion chamber body (2) does not exceed 100 mm from the plane of the castable material on the inner wall of the secondary combustion chamber body (2).

9. The auxiliary combustion device of the secondary combustion chamber of a rotary kiln according to claim 5, characterized in that: The flow meter (14) is an integrated thermal gas flow meter.

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