A cement kiln tail flue gas desulfurization device

Abstract

The present invention proposes a cement kiln tail flue gas desulfurization device, comprising a preheating cyclone separator, a waste heat recovery device, a first fan, a vertical mill, a dust collector, a second fan, and a chimney, which are sequentially arranged according to the flow direction of the flue gas. The flue gas enters the waste heat recovery device after passing through the preheating cyclone separator, and then enters the dust collector for treatment through the vertical mill, and finally is discharged into the atmosphere through the chimney. The smoke outlet of the waste heat recovery device is also connected to a spray cooling tower, and the smoke outlet of the spray cooling tower is connected to the dust collector. The flue gas cooled by the spray cooling tower enters the dust collector, and the bottom discharge port of the spray cooling tower is connected to a conveying device, and part of the reaction products are conveyed to the biological homogenization reservoir through the conveying device. The present invention provides a simple structure, economical and effective desulfurization technology, which is easy to transform, low in investment, small in footprint, and the reaction products can be comprehensively reused, and the operating cost is low.

Description

[Technical field]

[0001] The invention relates to the technical field of environmental protection machinery, in particular to a cement kiln tail flue gas desulfurization device. [Background technology]

[0002] At present, the flue gas from the kiln tail of most domestic cement clinker production lines is discharged into the atmosphere after being treated with bag or electric bag dust collectors. Since the alkaline substances in the decomposition furnace and vertical mill on the production line have a certain absorption effect on SO2 in the flue gas, there is generally no need to set up a separate desulfurization treatment system to meet the current environmental emission requirements.

[0003] The current standard stipulates that the SO2 content of the flue gas at the tail of the cement clinker production line should be less than 200 mg / Nm 3 The emission requirements of cement clinker production line kiln tail flue gas treatment environmental protection equipment can meet this emission requirement. With the improvement of environmental protection requirements, Jiangsu, Shandong, Henan and other provinces and cities have proposed that the SO2 of cement clinker production line kiln tail flue gas should be lower than 50mg / Nm 3 More stringent emission requirements, because the vertical mill is turned on and off according to the amount of raw material in the homogenization silo, when the vertical mill is turned on, the SO2 in the flue gas can meet the requirements of less than 50mg / Nm 3 This requirement, but when the vertical mill is stopped, SO2 will exceed the standard;

[0004] Although the traditional wet and dry desulfurization technologies have high desulfurization efficiency, they require large investment, occupy a large area, and have high operating costs. Now we need a simple, economical and effective desulfurization device that can treat SO2 in flue gas when the vertical mill is stopped, so as to achieve SO2 below 50mg / Nm 3 requirements. [Summary of the invention]

[0005] The purpose of the present invention is to solve the problems in the prior art and to provide a cement kiln tail flue gas desulfurization device, which is easy to transform, has low investment, occupies a small area, can comprehensively utilize the reaction products, and has low operating costs.

[0006] To achieve the above-mentioned purpose, the present invention proposes a cement kiln tail flue gas desulfurization device, comprising a preheating cyclone separator, a waste heat recovery device, a first fan, a vertical mill, a dust collector, a second fan, and a chimney which are arranged in sequence according to the flow direction of the flue gas. The flue gas enters the waste heat recovery device after passing through the preheating cyclone separator, and then enters the dust collector for treatment through the vertical mill, and is finally discharged into the atmosphere through the chimney. The smoke outlet of the waste heat recovery device is also connected to a spray cooling tower, and the smoke outlet of the spray cooling tower is connected to the dust collector. The flue gas cooled by the spray cooling tower enters the dust collector, and the bottom discharge port of the spray cooling tower is connected to a conveying device, through which part of the reaction products are conveyed to a biological homogenization tank.

[0007] Preferably, a digestion feeding device is arranged at the front end flue of the spray cooling tower, and the front end flue and the digestion feeding device are connected by a drop inclined pipe. The drop inclined pipe is inclinedly arranged, and the high end of the drop inclined pipe is connected to the digestion feeding device, and the low end of the drop inclined pipe is connected to the front end flue.

[0008] Preferably, a flow guide and equalizing device is provided in the front end flue to ensure that the desulfurization reactants entering the spray cooling tower are fully and evenly mixed with the flue gas, and the position of the flow guide and equalizing device is higher than the position of the lower end of the falling inclined pipe.

[0009] Preferably, the digestion feeding device is also connected to a reactant feeding device and a process water inlet pipe, and an agitator is provided in the shell of the digestion feeding device.

[0010] Preferably, the bottom discharge port of the front flue is connected to a conveying device, and part of the reaction products are conveyed to the biological homogenization reservoir through the conveying device.

[0011] Preferably, the inlet end of the waste heat recovery device is provided with a bypass directly connected to the preheating cyclone separator and the first fan.

[0012] Preferably, the dust collector is a bag dust collector or an electric bag dust collector.

[0013] Beneficial effects of the present invention: The present invention provides a desulfurization technology with simple structure and economical efficiency through the coordination of preheating cyclone separator, waste heat recovery device, first fan, vertical mill, spray cooling tower, dust collector, second fan, chimney, etc. When the vertical mill is turned on, the flue gas is cooled by the vertical mill. When the vertical mill is stopped, the flue gas is cooled by the spray cooling tower. The reaction products carried away by the flue gas are processed by the subsequent dust removal device and finally discharged from the chimney. Part of the reaction products collected in the spray cooling tower can be sent to the raw material homogenization warehouse for reuse. Since the amount of reaction products is very small, it will not affect the raw material. The equipment resistance increase is small, and there is no need to modify the fan.

[0014] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0015] Figure 1 The invention discloses a flue gas treatment flow chart of a flue gas desulfurization device at the tail of a cement kiln. [Specific implementation method]

[0016] See also Figure 1The present invention discloses a flue gas desulfurization device at the tail of a cement kiln, comprising a preheating cyclone separator 1, a waste heat recovery device 2, a first fan 3, a vertical mill 4, a dust collector 13, a second fan 14, and a chimney 15, which are arranged in sequence according to the flow direction of the flue gas. The flue gas enters the waste heat recovery device 2 after passing through the preheating cyclone separator 1, and then enters the dust collector 13 for treatment through the vertical mill 4, and is finally discharged into the atmosphere through the chimney 15. The smoke outlet of the waste heat recovery device 2 is also connected to a spray cooling tower 5, and the smoke outlet of the spray cooling tower 5 is connected to the dust collector 13. The flue gas cooled by the spray cooling tower 5 enters the dust collector 13, and the bottom discharge port of the spray cooling tower 5 is connected to a conveying device 12, and part of the reaction products are conveyed to a biological homogenization reservoir 16 through the conveying device 12. The front end flue 6 of the spray cooling tower 5 is provided with a digestion feeding device 7, and the front end flue 6 and the digestion feeding device 7 are connected through a drop inclined pipe 10, and the drop inclined pipe 10 is inclined. The high end of the drop inclined pipe 10 is connected to the digestion feeding device 7, and the low end of the drop inclined pipe 10 is connected to the front end flue 6. A flow guide and equalizing device 11 is provided in the front end flue 6 to make the desulfurization reactant entering the spray cooling tower 5 and the flue gas fully and evenly mixed. The position of the flow guide and equalizing device 11 is higher than the position of the low end of the drop inclined pipe 10. The digestion feeding device 7 is also connected to a reactant feeding device and a process water inlet pipe 9, and a stirrer 8 is provided in the shell of the digestion feeding device 7. The bottom discharge port of the front end flue 6 is connected to a conveying device 12, and part of the reaction product is conveyed to the biological homogenization reservoir 16 through the conveying device 12. The inlet end of the waste heat recovery device 2 is provided with a bypass directly connected to the preheating cyclone separator 1 and the first fan 3. The dust collector 13 is a bag dust collector or an electric bag dust collector.

[0017] Working process of the present invention:

[0018] The working principle of a cement kiln tail flue gas desulfurization device of the present invention is as follows:

[0019] When the vertical mill 4 is turned on, the flue gas at the kiln tail of the cement clinker production line enters the waste heat recovery device 2 after passing through the first-stage preheating cyclone separator, and then enters the vertical mill 4, and is finally discharged into the atmosphere after being treated by the bag or electric bag dust collector 13. The flue gas temperature at the outlet of the waste heat recovery device 2 is generally around 180°C, and the temperature of the flue gas drops to around 100°C after passing through the vertical mill 4.

[0020] When the vertical mill 4 is stopped, the flue gas at the kiln tail of the cement clinker production line enters the waste heat recovery device after passing through the first-stage preheating cyclone separator, and then enters the spray cooling tower 5, and is finally discharged into the atmosphere after being treated by the bag or electric bag dust collector 13. Since the flue gas temperature at the outlet of the waste heat recovery device 2 is generally around 180°C, in order to protect the bag, the flue gas needs to be cooled by the spray cooling tower 5 before entering the bag or electric bag dust collector 13.

[0021] The flue gas entering the spray cooling tower 5 is generally in the upper part and out the lower part. A digestion feeding device 7 (the device includes a shell, a stirrer 8, a falling inclined pipe 10, and is connected to process water) is arranged at the front end flue 6 of the spray cooling tower 5 and is equipped with a flow guide and equalizing device 11 to make the desulfurization reactant (the main component is powdered Ca(OH)2) entering the spray cooling tower 5 fully and evenly mixed with the flue gas, and react in the spray cooling tower 5 to remove SO2 to 50mg / Nm 3 Next, the front end flue 6 of the spray cooling tower and the bottom of the spray cooling tower 5 are partially modified to collect a part of the reaction products, which are then sent to the raw material homogenization warehouse 16 through the conveying device 12, and the other part of the reaction products carried away with the flue gas can be processed by the dust removal equipment behind.

[0022] The reaction product can be sent to the raw material homogenization storage 16 for reuse. Since the amount of the reaction product is very small, it will not affect the raw material, the increase in equipment resistance is small, and there is no need to modify the fan.

[0023] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention belongs to the protection scope of the present invention.

Claims

1. A cement kiln tail flue gas desulfurization device, characterized in that: The invention comprises a preheating cyclone separator (1), a waste heat recovery device (2), a first fan (3), a vertical mill (4), a dust collector (13), a second fan (14), and a chimney (15) which are arranged in sequence according to the flow direction of the flue gas. The flue gas enters the waste heat recovery device (2) after passing through the preheating cyclone separator (1), then enters the dust collector (13) for treatment through the vertical mill (4), and finally is discharged into the atmosphere through the chimney (15). The smoke outlet of the waste heat recovery device (2) is also connected to a spray cooling tower (5), and the smoke outlet of the spray cooling tower (5) is connected to the dust collector (13). The smoke gas after being cooled by the spray cooling tower (5) enters the dust collector (13). The bottom discharge port of the spray cooling tower (5) is connected to a conveying device (12). The conveying device (12) conveys part of the reaction product to the biological homogenization reservoir (16). The front end flue (6) of the spray cooling tower (5) is provided with a digestion feeding device (7). The front end flue (6) and the digestion feeding device (7) are connected via a drop inclined pipe (10). The drop inclined pipe (10) is arranged at an angle. The high end of the drop inclined pipe (10) is connected to the digestion feeding device (7), and the low end of the drop inclined pipe (10) is connected to the front end flue (6). A flow guide and equalizing device (11) is provided in the front end flue (6) so that the desulfurization reactant entering the spray cooling tower (5) is fully and evenly mixed with the flue gas. The position of the flow guide and equalizing device (11) is higher than the position of the low end of the drop inclined pipe (10).

2. A cement kiln tail flue gas desulfurization device as claimed in claim 1, characterized in that: The digestion feeding device (7) is also connected to a reactant feeding device and a process water inlet pipe (9), and a stirrer (8) is provided in the shell of the digestion feeding device (7).

3. A cement kiln tail flue gas desulfurization device as claimed in claim 1, characterized in that: The bottom discharge port of the front flue (6) is connected to a conveying device (12), and part of the reaction products are conveyed to the biological homogenization reservoir (16) via the conveying device (12).

4. A cement kiln tail flue gas desulfurization device as claimed in claim 1, characterized in that: The inlet end of the waste heat recovery device (2) is provided with a bypass directly connected to the preheating cyclone separator (1) and the first fan (3).

5. A cement kiln tail flue gas desulfurization device as claimed in claim 1, characterized in that: The dust collector (13) is a bag dust collector or an electric bag dust collector.

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