A sludge treatment coupled coal-fired boiler system

Abstract

The present invention discloses a sludge treatment coupled coal-fired boiler system, comprising a furnace, a tail flue and a sludge drying and crushing device, wherein the furnace is connected to the tail flue, a sludge burner is arranged on the furnace, and a smoke extraction pipe is arranged on the tail flue; the sludge drying and crushing device has a flue gas inlet, a sludge inlet and a smoke powder outlet, wherein the flue gas inlet is connected to the smoke extraction pipe, and the smoke powder outlet is connected to the sludge burner, and the sludge drying and crushing device is used to receive part of the flue gas dried sludge discharged from the tail flue and grind the dried sludge into powder, so that the flue gas carries the powdered sludge and transports it to the sludge burner for combustion. The sludge treatment coupled coal-fired boiler system of the present invention avoids the secondary pollution problem that may be caused by direct landfilling of untreated sludge, helps to improve the combustion efficiency of the boiler, reduces energy consumption, reduces the cost of sludge treatment, and helps to reduce the emission of harmful substances such as dioxins.

Description

Technical Field

[0001] The invention relates to the technical field of coal-fired boilers, and in particular to a sludge treatment coupled coal-fired boiler system. Background Art

[0002] With the rapid development of my country's economy and society, the urbanization process has accelerated, sewage treatment facilities have been continuously improved, and the urban sewage treatment capacity has been significantly improved. However, a large amount of residual sludge will be generated in the sewage treatment process, and the treatment and disposal of sludge has become a major challenge facing the current environmental protection field. Traditional sludge treatment methods mainly include landfill, composting, natural drying and incineration. Among them, landfill is the most common treatment method, but a large amount of sludge is directly landfilled without standardized treatment, which is easy to cause secondary pollution. The composting and natural drying treatment cycles are long and the effect is not good. Although incineration treatment can achieve reduction, the operating cost is high and it is easy to produce harmful substances such as dioxins. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention proposes a sludge treatment coupled coal-fired boiler system.

[0005] The sludge treatment coupled coal-fired boiler system of the embodiment of the present invention includes a furnace, a tail flue and a sludge drying and crushing device, the furnace is connected to the tail flue, a sludge burner is provided on the furnace, and a smoke extraction pipe is provided on the tail flue; the sludge drying and crushing device has a flue gas inlet, a sludge inlet and a smoke powder outlet, the flue gas inlet is connected to the smoke extraction pipe, and the smoke powder outlet is connected to the sludge burner, and the sludge drying and crushing device is used to receive part of the flue gas dried sludge discharged from the tail flue and grind the dried sludge into powder, so that the flue gas carries the powdered sludge to the sludge burner for combustion.

[0006] In some embodiments, the temperature of the flue gas entering the sludge drying and pulverizing device from the flue gas inlet is 500°C-550°C, and the temperature of the flue gas discharged from the flue gas powder outlet is 180°C-200°C.

[0007] In some embodiments, the sludge drying and crushing device includes a rotary drying section and a crushing and conveying section. The rotary drying section is connected to the flue gas inlet and the sludge inlet, and the crushing and conveying section is connected to the flue gas powder outlet. The rotary drying section is used for direct contact between flue gas and sludge to evaporate the moisture in the sludge, and the crushing and conveying section is used to grind the dried sludge into powder.

[0008] In some embodiments, the rotary drying section includes a drum, the drum is used to place the sludge, a plurality of steel balls are arranged inside the drum, and the steel balls are used to grind the sludge into powder when the drum rotates.

[0009] In some embodiments, the pressure in each of the rotary drying section and the pulverizing and conveying section is less than standard atmospheric pressure.

[0010] In some embodiments, the sludge treatment coupled coal-fired boiler system of the embodiment of the present invention includes a booster fan, and an air inlet and an air outlet of the booster fan are respectively connected to the smoke and powder outlet and the sludge burner.

[0011] In some embodiments, the sludge treatment coupled coal-fired boiler system of the embodiments of the present invention also includes a cyclone dust collector, which has an air inlet, an exhaust port and a dust exhaust port, the air inlet is connected to the flue gas outlet to receive the flue gas and powdered sludge discharged from the smoke and powder outlet, the exhaust port is connected to the air inlet of the booster fan to separate the powdered sludge in the flue gas, and the outlet of the booster fan is connected to the dust exhaust port to transport the powdered sludge separated by the cyclone dust collector to the sludge burner.

[0012] In some embodiments, the booster fan is a centrifugal fan.

[0013] In some embodiments, the sludge treatment coupled coal-fired boiler system of the embodiment of the present invention also includes a storage bin and a feeder, wherein the storage bin is used to store sludge, and the storage bin is connected to the sludge inlet through the feeder to transport the sludge to the sludge drying and crushing device.

[0014] In some embodiments, the sludge treatment coupled coal-fired boiler system of the embodiments of the present invention also includes a dust collector, a desulfurization tower and a chimney. The dust collector is connected to the tail flue to remove dust from the flue gas discharged from the tail flue, the desulfurization tower is connected to the dust collector to desulfurize the flue gas after dust removal, and the chimney is connected to the desulfurization tower to discharge the desulfurized flue gas.

[0015] The sludge treatment coupled with the coal-fired boiler system in the embodiment of the present invention effectively treats the sludge and avoids the secondary pollution problem that may be caused by direct landfill of untreated sludge. Sludge that is dried and ground into powder is easier to burn, which helps to improve the combustion efficiency of the boiler and reduce energy consumption. Traditional sludge treatment methods such as landfill, composting, natural drying and incineration are relatively costly. The present invention reduces the cost of sludge treatment by coupling the coal-fired boiler system and utilizing the waste heat of the boiler to dry the sludge. By burning the sludge in the furnace, the harmful substances generated during the combustion process can be effectively controlled, which helps to reduce the emission of harmful substances such as dioxins. In addition, the use of sludge as fuel realizes the resource utilization of waste and contributes to the development of a circular economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of a sludge treatment coupled coal-fired boiler system according to an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of a sludge drying and crushing device according to an embodiment of the present invention.

[0018] Reference numerals:

[0019] 100. Sludge treatment coupled coal-fired boiler system; 1. Furnace; 2. Tail flue; 3. Sludge burner; 4. Smoke extraction pipe; 5. Sludge drying and crushing device; 501. Smoke inlet; 502. Sludge inlet; 503. Smoke powder outlet; 504. Rotary drying section; 5041. Rotating drum; 505. Crushing and conveying section; 6. Steel balls; 7. Booster fan; 8. Cyclone dust collector; 801. Air inlet; 802. Exhaust outlet; 803. Dust outlet; 9. Storage bin; 10. Feeder; 11. Dust collector; 12. Desulfurization tower; 13. Chimney. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0021] like Figure 1 and Figure 2As shown, the sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention includes a furnace 1, a tail flue 2 and a sludge drying and crushing device 5. The furnace 1 is connected to the tail flue 2, a sludge burner 3 is provided on the furnace 1, and a smoke extraction pipe 4 is provided on the tail flue 2. The sludge drying and crushing device 5 has a flue gas inlet 501, a sludge inlet 502 and a smoke powder outlet 503, the flue gas inlet 501 is connected to the smoke extraction pipe 4, and the smoke powder outlet 503 is connected to the sludge burner 3. The sludge drying and crushing device 5 is used to receive part of the flue gas dried sludge discharged from the tail flue 2 and grind the dried sludge into powder, so that the flue gas carries the powdered sludge to the sludge burner 3 for combustion.

[0022] The sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention includes a furnace 1, a tail flue 2 and a sludge drying and crushing device 5. The furnace 1 is the main combustion area of ​​the coal-fired boiler, the tail flue 2 is responsible for extracting the flue gas after combustion, and the sludge drying and crushing device 5 receives part of the flue gas discharged from the tail flue 2 and uses the heat of the flue gas to dry the sludge. The dried powdered sludge is fed into the sludge burner 3 and burned together with the coal in the furnace 1. In this way, not only the sludge is treated, but also the sludge can be used as fuel to improve the combustion efficiency of the boiler.

[0023] The sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention effectively treats the sludge and avoids the secondary pollution problem that may be caused by direct landfill of untreated sludge. Sludge that is dried and ground into powder is easier to burn, which helps to improve the combustion efficiency of the boiler and reduce energy consumption. Traditional sludge treatment methods such as landfill, composting, natural drying and incineration are relatively costly. The present invention reduces the cost of sludge treatment by coupling the coal-fired boiler system and utilizing the waste heat of the boiler to dry the sludge. By burning the sludge in the furnace 1, the harmful substances generated during the combustion process can be effectively controlled, which helps to reduce the emission of harmful substances such as dioxins. In addition, the use of sludge as fuel realizes the resource utilization of waste and contributes to the development of a circular economy.

[0024] In some embodiments, the temperature of the flue gas entering the sludge drying and pulverizing device 5 through the flue gas inlet 501 is 500°C-550°C, and the temperature of the flue gas discharged from the flue gas powder outlet 503 is 180°C-200°C.

[0025] The flue gas temperature entering the sludge drying and crushing device 5 is set to 500℃-550℃. This temperature range is usually high enough to effectively evaporate the water in the sludge and achieve the purpose of drying. This temperature range also takes into account the actual temperature range of the flue gas in the tail flue 2 of the coal-fired boiler, and can make full use of the waste heat of the boiler without additional heating. The temperature is set in this range, which can not only ensure the drying effect, but also avoid the risk of sludge ignition or equipment damage caused by excessive temperature.

[0026] The temperature of the flue gas discharged from the sludge drying and crushing device 5 is reduced to 180℃-200℃, indicating that the sludge has completed the drying process and the water has been evaporated. The control of the outlet temperature can prevent the sludge from overheating and avoid the production of by-products such as tar, and is also conducive to the long-term stable operation of the equipment. The lower temperature means that part of the heat has been absorbed by the sludge, which helps to improve the thermal efficiency of the entire system and reduce energy waste. The lower temperature is also conducive to reducing the impact on the environment and avoiding the thermal pollution that may be caused by the direct discharge of high-temperature flue gas.

[0027] In some embodiments, the sludge drying and pulverizing device 5 includes a rotary drying section 504 and a pulverizing and conveying section 505. The rotary drying section 504 is connected to the flue gas inlet 501 and the sludge inlet 502, and the pulverizing and conveying section 505 is connected to the flue gas and sludge outlet 503. The rotary drying section 504 is used for direct contact between flue gas and sludge to evaporate the water in the sludge, and the pulverizing and conveying section 505 is used to grind the dried sludge into powder.

[0028] In the rotary drying section 504, the high-temperature flue gas is in direct contact with the sludge, and the heat is transferred to the sludge, causing the water in the sludge to evaporate quickly. The rotating action helps the sludge to be evenly distributed in the drying section, increases the contact area with the flue gas, and improves the drying efficiency. The crushing and conveying section 505 is connected to the smoke powder outlet 503, and its function is to further grind the dried sludge into powder and convey it to the sludge burner 3. The dried sludge is usually fragile and easy to grind into powder. Equipment such as a grinder or a hammer crusher can be set in the crushing and conveying section 505 to crush the sludge particles into finer powder. The crushed sludge powder needs to be conveyed to the sludge burner 3, which is usually achieved by conveyor belts, fans or air flow conveying.

[0029] The sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention can optimize the respective process parameters respectively by setting the drying and crushing functions in two different sections, thereby improving the efficiency of the entire sludge treatment process. The direct contact drying method of the rotary drying section 504 can quickly and effectively remove moisture from the sludge and reduce the drying time. Since drying and crushing are carried out in different stages, energy consumption can be adjusted according to the respective process requirements, thereby achieving overall energy savings. The dried sludge powder is easier to burn completely, which improves combustion efficiency and reduces the emission of harmful substances. Through effective drying and crushing, secondary pollution generated during the sludge treatment process can be reduced.

[0030] In some embodiments, the rotary drying section 504 includes a drum 5041 for placing sludge. A plurality of steel balls 6 are disposed in the drum 5041 for grinding the sludge into powder when the drum 5041 rotates.

[0031] The drum 5041 is the core part of the rotary drying section 504, which is usually a large cylindrical container installed horizontally or slightly tilted. The sludge enters the drum 5041 through the feed port and moves with the rotation of the drum 5041. During the rotation of the drum 5041, the sludge moves together with the steel balls 6 inside the drum. Due to the impact and friction of the steel balls 6, the sludge is not only dried in the drum 5041, but also ground into powder. The steel balls 6 are important media in the grinding process. When the drum 5041 rotates, the steel balls 6 are lifted to a certain height due to the centrifugal force, and then fall, impacting and grinding the sludge, thereby grinding the sludge into powder. The use of the steel balls 6 can significantly improve the grinding efficiency, reduce the required drying and grinding time, and improve the fineness of the powder. By adjusting the size, quantity and material of the steel balls 6, the grinding effect can be controlled to obtain sludge powder of different particle sizes.

[0032] The steel balls 6 in the drum 5041 not only assist in drying the sludge, but also complete the grinding work, realizing the integration of drying and grinding and simplifying the process. The design of the drum 5041 and the use of the steel balls 6 improve the sludge treatment capacity, can treat a large amount of sludge, and adapt to different treatment requirements. The integrated design reduces the intermediate links and reduces the energy consumption of the system. The ground sludge powder has better combustion performance and can burn more fully, improving the combustion efficiency of the boiler. The integrated equipment reduces the construction and operation costs, which helps to reduce the cost of the entire sludge treatment process.

[0033] In some embodiments, the pressure in each of the rotary drying section 504 and the pulverizing and conveying section 505 is less than the standard atmospheric pressure, so that the rotary drying section 504 and the pulverizing and conveying section 505 are always in a negative pressure state.

[0034] In order to maintain the negative pressure state, the system may be equipped with a special negative pressure generating device, such as a vacuum pump, and a corresponding control mechanism to adjust the pressure. The negative pressure state helps prevent the dust generated during the sludge drying and grinding process from leaking into the external environment, reducing the health risks to operators and the impact on the environment. In a negative pressure environment, even if there is a leak in the equipment, air will flow from the outside into the equipment instead of the other way around, which helps prevent combustible dust from mixing with air to form an explosive gas mixture. Negative pressure can help materials (such as dried sludge powder) flow more smoothly inside the system, reducing the risk of material clogging the pipeline. In a negative pressure environment, water is more likely to evaporate from the sludge because the reduced pressure inside the drying section lowers the boiling point of water, allowing the water to evaporate at a lower temperature.

[0035] In some embodiments, the sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention includes a booster fan 7, and an air inlet and an air outlet of the booster fan 7 are respectively connected to the smoke and powder outlet 503 and the sludge burner 3.

[0036] In some embodiments, the sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention further includes a cyclone dust collector 8, which has an air inlet 801, an exhaust port 802 and a dust exhaust port 803. The air inlet 801 is connected to the flue gas outlet to receive the flue gas and powdered sludge discharged from the smoke powder outlet 503. The exhaust port 802 is connected to the air inlet of the booster fan 7 to separate the powdered sludge in the flue gas. The outlet of the booster fan 7 is connected to the dust exhaust port 803 to transport the powdered sludge separated by the cyclone dust collector 8 to the sludge burner 3.

[0037] The cyclone dust collector 8 is a device that uses centrifugal force to separate solid particles (such as powdered sludge) in the flue gas from the air flow. When the flue gas and powdered sludge enter the cyclone dust collector 8 through the air inlet 801, the air flow will rotate inside the dust collector 11, generating centrifugal force. Since the density of the powdered sludge is greater than that of the flue gas, it will be thrown to the wall of the dust collector 11 and slide along the wall to the dust outlet 803. The cyclone dust collector 8 can efficiently separate the powdered sludge from the flue gas.

[0038] The powdery sludge separated by the cyclone dust collector 8 is then directly transported to the sludge burner 3 for combustion through the air outlet of the booster fan 7, which can prevent the flue gas from carrying the powdery sludge through the booster fan 7 and causing serious wear to the booster fan 7, which is beneficial to extending the service life of the booster fan 7. The cyclone dust collector 8 can reduce the unstable factors caused by dust carrying and enhance the stable operation of the entire system.

[0039] In some embodiments, the booster fan 7 is a centrifugal fan. The main function of the booster fan 7 is to increase the pressure of the airflow, thereby achieving airflow transportation of the sludge powder. The centrifugal fan is selected as the booster fan 7 because of its high efficiency and stability.

[0040] In some embodiments, the sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention also includes a storage bin 9 and a feeder 10. The storage bin 9 is used to store sludge. The storage bin 9 is connected to the sludge inlet 502 through the feeder 10 to transport the sludge to the sludge drying and crushing device 5.

[0041] The main function of the storage silo 9 is to store sludge. It can provide a temporary storage space for the sludge to ensure that the sludge can be stored safely and orderly before it needs to be processed. The storage silo 9 also has a buffering effect and can adjust between the sludge supply and processing capacity to cope with possible imbalances in supply and demand. The storage silo 9 can optimize the logistics process of the sludge and reduce losses during transportation and processing through centralized storage and batch processing. The feeder 10 is responsible for conveying the sludge in the storage silo 9 to the sludge inlet 502 of the sludge drying and crushing device 5 to ensure that the sludge can enter the drying and crushing system continuously and evenly. The feeder 10 can usually control the conveying speed and amount of the sludge to ensure the stability of the sludge treatment process.

[0042] The storage bin 9 is connected to the sludge inlet 502 of the sludge drying and crushing device 5 through the feeder 10, forming a complete sludge treatment process. Through the coordinated use of the storage bin 9 and the feeder 10, it can be ensured that the sludge treatment system can still maintain stable operation when the sludge supply is unstable or the treatment demand changes. When the sludge treatment equipment needs maintenance or overhaul, the storage bin 9 can provide sufficient sludge storage space to reduce the downtime of the system. The feeder 10 can adjust the sludge delivery volume according to the real-time needs of the system to improve the sludge treatment efficiency. The design of the storage bin 9 and the feeder 10 can adapt to sludge of different types and properties, improving the adaptability of the system. The use of the storage bin 9 and the feeder 10 reduces the direct exposure and manual operation of the sludge and improves the working environment. Through a closed conveying system, the impact of dust and odor generated during the sludge treatment process on the environment can be reduced.

[0043] In some embodiments, the sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention further includes a dust collector 11, a desulfurization tower 12 and a chimney 13. The dust collector 11 is connected to the tail flue 2 to remove dust from the flue gas discharged from the tail flue 2, the desulfurization tower 12 is connected to the dust collector 11 to desulfurize the flue gas after dust removal, and the chimney 13 is connected to the desulfurization tower 12 to discharge the desulfurized flue gas.

[0044] The dust collector 11 is a device for capturing solid particulate matter in the flue gas. It separates the particulate matter from the flue gas by physical, chemical or electrical methods. The dust collector 11 is connected to the tail flue 2 to remove dust from the flue gas discharged from the tail flue 2 to reduce the emission of particulate matter in the flue gas. The desulfurization tower 12 is a device for removing acidic gases such as sulfur dioxide (SO2) from the flue gas. It usually converts SO2 into solid or liquid form through chemical reactions, thereby reducing its emissions. The desulfurization tower 12 is connected to the dust collector 11 to desulfurize the flue gas after dust removal to further reduce pollutants in the flue gas. The chimney 13 is a device for discharging the desulfurized flue gas. The height and diameter design of the chimney 13 helps to reduce the pollution of the flue gas to the ground, and also helps to diffuse and dilute the flue gas.

[0045] The sludge treatment coupled coal-fired boiler system 100 of the embodiment of the present invention effectively removes particulate matter and harmful gases such as SO2 in the flue gas through the treatment of the dust collector 11 and the desulfurization tower 12, thereby reducing air pollution. The dust collector 11 can remove particulate matter in the flue gas, improve combustion efficiency, and reduce energy waste. The system design of the embodiment of the present invention helps to meet strict environmental regulations and emission standards. Reducing pollutant emissions helps to improve air quality and protect the environment and human health.

[0046] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0047] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0050] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0051] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A sludge treatment coupled coal-fired boiler system, characterized in that: include: A furnace (1) and a tail flue (2), wherein the furnace (1) is connected to the tail flue (2), a sludge burner (3) is provided on the furnace (1), and a smoke extraction pipe (4) is provided on the tail flue (2); A sludge drying and pulverizing device (5), the sludge drying and pulverizing device (5) having a flue gas inlet (501), a sludge inlet (502) and a smoke powder outlet (503), the flue gas inlet (501) being connected to the smoke extraction pipe (4), the smoke powder outlet (503) being connected to the sludge burner (3), the sludge drying and pulverizing device (5) being used for receiving part of the flue gas dried sludge discharged from the tail flue (2) and grinding the dried sludge into powder, so that the flue gas carries the powdered sludge to be transported to the sludge burner (3) for combustion.

2. The sludge treatment coupled coal-fired boiler system according to claim 1, characterized in that: The temperature of the flue gas entering the sludge drying and pulverizing device (5) through the flue gas inlet (501) is 500°C-550°C, and the temperature of the flue gas discharged from the flue gas powder outlet (503) is 180°C-200°C.

3. The sludge treatment coupled coal-fired boiler system according to claim 1, characterized in that: The sludge drying and pulverizing device (5) comprises a rotary drying section (504) and a pulverizing and conveying section (505); the rotary drying section (504) is connected to the flue gas inlet (501) and the sludge inlet (502); the pulverizing and conveying section (505) is connected to the flue gas and sludge outlet (503); the rotary drying section (504) is used for direct contact between flue gas and sludge to evaporate water in the sludge; and the pulverizing and conveying section (505) is used for grinding the dried sludge into powder.

4. The sludge treatment coupled coal-fired boiler system according to claim 3, characterized in that: The rotary drying section (504) comprises a rotating drum (5041) for placing sludge. A plurality of steel balls (6) are arranged inside the rotating drum (5041) and the steel balls (6) are used to grind the sludge into powder when the rotating drum (5041) rotates.

5. The sludge treatment coupled coal-fired boiler system according to claim 3, characterized in that: The pressure in each of the rotary drying section (504) and the pulverizing and conveying section (505) is less than the standard atmospheric pressure.

6. The sludge treatment coupled coal-fired boiler system according to claim 1, characterized in that: It comprises a booster fan (7), the air inlet and the air outlet of the booster fan (7) being respectively connected to the smoke and powder outlet (503) and the sludge burner (3).

7. The sludge treatment coupled coal-fired boiler system according to claim 6, characterized in that: It also includes a cyclone dust collector (8), the cyclone dust collector (8) having an air inlet (801), an air outlet (802) and a dust outlet (803), the air inlet (801) being connected to the flue gas outlet to receive the flue gas and powdered sludge discharged from the smoke and powder outlet (503), the exhaust port (802) being connected to the air inlet of the booster fan (7) to separate the powdered sludge in the flue gas, and the outlet of the booster fan (7) being connected to the dust outlet (803) to transport the powdered sludge separated by the cyclone dust collector (8) to the sludge burner (3).

8. The sludge treatment coupled coal-fired boiler system according to claim 6, characterized in that: The booster fan (7) is a centrifugal fan.

9. The sludge treatment coupled coal-fired boiler system according to claim 1, characterized in that: It also includes a storage bin (9) and a feeder (10), wherein the storage bin (9) is used to store sludge, and the storage bin (9) is connected to the sludge inlet (502) via the feeder (10) to transport the sludge to the sludge drying and crushing device (5).

10. The sludge treatment coupled coal-fired boiler system according to claim 1, characterized in that: It also includes a dust collector (11), a desulfurization tower (12) and a chimney (13), wherein the dust collector (11) is connected to the tail flue (2) to remove dust from the flue gas discharged from the tail flue (2), the desulfurization tower (12) is connected to the dust collector (11) to desulfurize the flue gas after dust removal, and the chimney (13) is connected to the desulfurization tower (12) to discharge the desulfurized flue gas.

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