Hazardous waste co-treatment cement kiln tail waste gas treatment system

Abstract

The utility model discloses a hazardous waste co-treatment cement kiln tail waste gas treatment system which comprises a bypass ventilation subsystem, a coal mill waste gas treatment subsystem and a kiln tail waste gas treatment subsystem. Wherein the bypass ventilation subsystem comprises a decomposing furnace, the lower part of the decomposing furnace is connected with an exhaust fan, the exhaust fan is communicated with a shock cooling chamber, the shock cooling chamber is communicated with a cyclone cylinder, the cyclone cylinder is communicated with an air cooler, and the air cooler is communicated with a dust collector. According to the hazardous waste co-processing cement kiln tail waste gas treatment system, coal mill waste gas is introduced into a raw material grinding system, on one hand, secondary recycling of waste heat of the coal mill waste gas and coal dust can be achieved, on the other hand, the coal dust has a certain adsorption effect on pollutants such as heavy metal, and therefore the hazardous waste co-processing cement kiln tail waste gas treatment system is environmentally friendly. The bypass exhaust gas is introduced into the raw material grinding system, so that pollutants such as sulfur dioxide and particulate matters in the bypass exhaust system can be reduced, and the waste heat of the exhaust gas can be effectively utilized.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection of cement production, in particular to a hazardous waste coordinated disposal system for cement kiln tail gas. Background Art

[0002] The existing cement kiln system used for the coordinated disposal of hazardous waste is equipped with bag dust collectors at the kiln tail, coal mill, and bypass venting, and an online smoke dust monitoring system is installed at the chimney outlet at the kiln tail, which can monitor the organized emission of pollutants such as PM, SO2, NOx, HCl, HF, etc. in real time.

[0003] The existing exhaust gas system has the following deficiencies: First, the existing coal mill dust collector exhaust outlet is not equipped with an online smoke dust monitoring system, and mainly relies on manual regular inspection. Once the pollutant emission exceeds the standard, it cannot be discovered in time; second, the exhaust gas temperature at the coal mill dust collector outlet is generally around 70°C, and there is a problem of waste heat if it is directly discharged externally; third, the particle concentration of the exhaust gas at the coal mill dust collector outlet is generally 6.0-7.0 mg / m3, and there are certain energy waste and environmental pollution problems; fourth, in addition to conventional pollutants such as particulate matter, nitrogen oxides, and sulfur dioxide, the bypass vented flue gas also contains characteristic pollutants such as dioxins, heavy metals, and acidic gases. If this part of the flue gas is not pre-treated and directly connected to the kiln tail chimney, it will be mixed with the original exhaust gas and discharged, which will be difficult to meet the emission index requirements.

[0004] A cement kiln bypass venting coupled desulfurization and denitrification integrated system, application number: CN202121657924.0, the utility model discloses a cement kiln bypass venting coupled desulfurization and denitrification integrated system, including a quenching device, the quenching device includes a flue gas inlet and a flue gas outlet, the flue gas inlet of the quenching device is connected to the kiln tail smoke chamber through a bypass venting duct, and the flue gas outlet of the quenching device is connected to a cyclone collection device; the quenching device also includes a cold air inlet, which is connected to the fan through an air duct; a plurality of atomizing spray guns are embedded on the side wall of the quenching device, and the liquid inlet of each atomizing spray gun is connected to an external solution tank through a connecting pipe. The utility model may have two shortcomings. First, the primary cooling is adopted, and the chloride ion concentration of the recovered fly ash is low; second, the SO2 concentration in the exhaust gas is high, and a desulfurization system needs to be configured in the subsequent process; third, the waste heat of the exhaust gas at the outlet of the bypass venting dust collector is not reused for the second time.

[0005] In order to maximize the coordinated control of various pollutants in the coordinated disposal of hazardous waste cement kilns, make full use of waste heat resources, and implement centralized online monitoring of pollutant emissions at the tail of the cement kiln, a hazardous waste coordinated disposal cement kiln tail gas treatment system was developed. Utility Model Content

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies in the prior art, the utility model provides a hazardous waste coordinated disposal cement kiln tail gas treatment system, which solves the problems of low thermal utilization rate and ineffective control of pollutants in the existing cement hazardous waste treatment system.

[0008] (II) Technical solution

[0009] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a hazardous waste coordinated disposal cement kiln tail gas treatment system, including a bypass venting subsystem, a coal mill waste gas treatment subsystem, and a kiln tail waste gas treatment subsystem.

[0010] The bypass venting subsystem includes a decomposition furnace, the lower part of which is connected with an exhaust fan, the exhaust fan is connected with a quenching chamber, the quenching chamber is connected with a cyclone, the cyclone is connected with an air cooler, and the air cooler is connected with a dust collector.

[0011] The quenching chamber is also connected to the desulfurization spray gun and the denitrification ammonia spray gun respectively.

[0012] The coal mill exhaust gas treatment subsystem includes a coal mill bag dust collector and an exhaust fan, wherein the exhaust fan is also connected to the dust collector.

[0013] The kiln tail exhaust gas treatment subsystem includes a cement kiln, which is connected to a preheater, which is connected to a waste heat power generation boiler, which is connected to a high-temperature fan, which is connected to an inlet of a wind collector, which is also connected to an exhaust fan, which is connected to an outlet of a wind collector and a raw material mill, which is connected to a cyclone dust collector, which is connected to a circulating fan, which is connected to an activated carbon adsorption tower, which is connected to a dust collector at the kiln tail, which is connected to a tail exhaust fan, and which is connected to a chimney.

[0014] As a further preference, the coarse material outlet of the cyclone is connected to the kiln tail smoke chamber.

[0015] As further preferred, the preheater is also connected to a humidification tower.

[0016] As a further preference, the desulfurization spray gun and the denitrification ammonia spray gun can spray desulfurization agent and denitrification ammonia water into the quenching chamber respectively to desulfurize and denitrify the exhaust gas.

[0017] (III) Beneficial effects

[0018] The utility model provides a hazardous waste collaborative disposal cement kiln tail gas treatment system. It has the following

[0019] Beneficial effects:

[0020] 1. Introducing coal mill exhaust gas into the raw material grinding system can, on the one hand, realize the secondary recovery and utilization of waste heat and coal dust from coal mill exhaust gas. On the other hand, coal dust also has a certain adsorption effect on pollutants such as heavy metals.

[0021] 2. Introducing the bypass exhaust gas into the raw material grinding system can not only reduce pollutants such as sulfur dioxide and particulate matter in the bypass exhaust system, but also effectively utilize the waste heat of the exhaust gas.

[0022] 3. The bypass ventilation system adopts a two-stage cooling + desulfurization and denitrification system design, which has a good comprehensive effect of dechlorination, desulfurization and denitrification.

[0023] 4. Adding an activated carbon adsorption system at the kiln tail will be beneficial to the control of dioxins, heavy metal pollutants, etc. in hazardous waste disposal.

[0024] 5. Cancel the discharge port of the raw coal mill dust collector, combine the coal mill and kiln tail exhaust gas discharge port into one, and set up an online monitoring system, which is conducive to reducing pollutant emissions and reducing blind spots in online monitoring of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the utility model;

[0026] Figure 2 The figure is a schematic diagram of the prior art system for treating hazardous cement waste.

[0027] In the figure: 1. decomposition furnace; 2. coal mill bag dust collector; 3. cement kiln; 4. exhaust fan; 5. quenching chamber; 6. cyclone; 7. air cooler; 8. dust collector; 9. exhaust fan; 10. denitrification spray gun; 11. desulfurization spray gun; 12. wind box; 13. preheater; 14. waste heat power generation boiler; 15. high temperature fan; 16. raw material mill; 17. cyclone dust collector; 18. circulating fan; 19. activated carbon adsorption tower; 20. kiln tail dust collector; 21. tail exhaust fan; 22. chimney; 23. humidification tower; 24. kiln tail smoke chamber. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] like Figure 1-2 As shown, the utility model provides a technical solution: a hazardous waste coordinated disposal cement kiln tail exhaust gas treatment system, including a bypass venting subsystem, a coal mill exhaust gas treatment subsystem, and a kiln tail exhaust gas treatment subsystem.

[0030] The bypass venting subsystem includes a decomposition furnace 1, the lower part of which is connected to an exhaust fan 4, the exhaust fan 4 is connected to a quenching chamber 5, the quenching chamber 5 is connected to a cyclone 6, the coarse material outlet of the cyclone 6 is connected to a kiln tail smoke chamber 24, the cyclone 6 is connected to an air cooler 7 (the air cooler 7 is a product within the scope of the prior art and can be purchased directly), and the air cooler 7 is connected to a dust collector 8.

[0031] The quenching chamber 5 is also connected to the desulfurization spray gun 11 and the denitrification ammonia spray gun 10 respectively. The desulfurization spray gun 11 and the denitrification ammonia spray gun 10 can respectively spray desulfurization agent and denitrification ammonia water into the quenching chamber 5 to desulfurize and denitrify the exhaust gas.

[0032] The coal mill exhaust gas treatment subsystem includes a coal mill bag dust collector 2 and an exhaust fan 9 , wherein the exhaust fan 9 is also connected to the dust collector 8 .

[0033] The kiln tail exhaust gas treatment subsystem includes a cement kiln 3, which is connected to a preheater 13, which is also connected to a humidifying tower 23, which is connected to a waste heat power generation boiler 14, which is connected to a high-temperature fan 15, which is connected to an inlet of a wind collector 12, which is also connected to an exhaust fan 9, which is connected to an outlet of a wind collector 12 and a raw material mill 16, which is connected to a cyclone dust collector 17, which is connected to a circulating fan 18, which is connected to an activated carbon adsorption tower 19 (with multiple layers of honeycomb activated carbon filter layers therein), which is connected to a kiln tail dust collector 20, which is connected to a tail exhaust fan 21, which is connected to a chimney 22.

[0034] Meanwhile, the contents not described in detail in this specification belong to the prior art known to the professional and technical personnel in this field.

[0035] When in use, the exhaust gas extracted from the lower part of the decomposition furnace 1 is cooled and lowered in the quenching chamber 5 for the first stage, and then enters the cyclone 6 for separation. The collected coarse powder returns to the kiln tail smoke chamber 24, and the exhaust gas out of the cyclone 6 enters the air cooler 7 for secondary cooling and lowering. The fly ash is collected by the air cooler 7 and the dust collector 8, and then transported to the fly ash bin for separate treatment. The remaining exhaust gas is introduced into the exhaust fan 9 and transported to the wind box 12.

[0036] A desulfurization spray gun 11 and a denitrification spray gun 10 are provided in the quenching chamber 5, and cold air is blown into the chamber for cooling.

[0037] After the coal mill exhaust gas is processed by the coal mill bag dust collector 2, the exhaust gas is introduced into the wind box 12 in front of the raw mill 16 through the exhaust fan 9. Similarly, the waste heat exhaust gas from the cement kiln 3 is finally transported to the wind box 12 through the high-temperature fan 15.

[0038] Therefore, the wind box 12 mainly mixes the kiln tail exhaust gas from the high-temperature fan 15, the exhaust gas from the bypass exhaust system and the coal mill exhaust gas, and supplies them to the raw mill 16 for drying. The three mixed exhaust gases enter the raw mill 16, and while drying the materials, they can achieve the purpose of desulfurization and adsorption of dioxins and heavy metal pollutants through the activated carbon adsorption tower 19 at the kiln tail. In addition, the online smoke dust monitoring system at the kiln tail can uniformly detect the exhaust gases generated by the above three branches, saving costs.

[0039] It should be noted that the electrical components appearing in this article are all connected to the external main controller and 220V or 380V mains electricity, and the main controller can be a conventional known device for controlling computers, etc. Its control principle, internal structure and control switch mode are all conventional means of the prior art, which are directly quoted here without further elaboration. In this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0040] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hazardous waste collaborative disposal cement kiln tail gas treatment system, characterized by: Including bypass ventilation subsystem, coal mill waste gas treatment subsystem, kiln tail waste gas treatment subsystem; The bypass ventilation subsystem comprises a decomposition furnace (1), the lower part of the decomposition furnace (1) is connected to an exhaust fan (4), the exhaust fan (4) is connected to a quenching chamber (5), the quenching chamber (5) is connected to a cyclone (6), the cyclone (6) is connected to an air cooler (7), and the air cooler (7) is connected to a dust collector (8); The quenching chamber (5) is also connected to the desulfurization spray gun (11) and the denitrification spray gun (10) respectively; The coal mill waste gas treatment subsystem comprises a coal mill bag dust collector (2) and an exhaust fan (9), wherein the exhaust fan (9) is also connected to the dust collector (8); The kiln tail waste gas treatment subsystem comprises a cement kiln (3), wherein the cement kiln (3) is connected to a preheater (13), the preheater (13) is connected to a waste heat power generation boiler (14), the waste heat power generation boiler (14) is connected to a high temperature fan (15), the high temperature fan (15) is connected to an inlet of a wind collecting box (12), the inlet of the wind collecting box (12) is also connected to an exhaust fan (9), the outlet of the wind collecting box (12) is connected to a raw material mill (16), the raw material mill (16) is connected to a cyclone dust collector (17), the cyclone dust collector (17) is connected to a circulating fan (18), the outlets of the circulating fan (18) and the wind collecting box (12) are both connected to an activated carbon adsorption tower (19), the activated carbon adsorption tower (19) is connected to a kiln tail dust collector (20), the kiln tail dust collector (20) is connected to a tail exhaust fan (21), and the tail exhaust fan (21) is connected to a chimney (22).

2. According to claim 1, a hazardous waste coordinated disposal cement kiln tail gas treatment system is characterized by: The coarse material outlet of the cyclone (6) is communicated with the kiln tail smoke chamber (24).

3. According to claim 1, a hazardous waste coordinated disposal cement kiln tail gas treatment system is characterized by: The preheater (13) is also connected to the humidification tower (23).

4. According to claim 1, a hazardous waste coordinated disposal cement kiln tail gas treatment system is characterized by: The desulfurization spray gun (11) and the denitrification ammonia spray gun (10) can respectively spray desulfurization agent and denitrification ammonia water into the quenching chamber (5) to desulfurize and denitrify the exhaust gas.

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