Sludge pyrolysis gasification coupling oxygen-enriched combustion system

Abstract

The invention relates to the technical field of sludge treatment systems, in particular to a sludge pyrolysis gasification coupling oxygen-enriched combustion system. Through integrated design, efficient, environment-friendly and resource utilization of sludge treatment is realized. The whole process from sludge storage to final gas recovery and heat energy reutilization is closely connected, and a closed-loop system is formed. The air-drying preheater preheats the sludge to improve the pyrolysis efficiency, and the roller crusher ensures that the granularity of the residues is uniform and is beneficial to gasification. Through combination of gasification and oxygen-enriched combustion, pollutant emission is reduced, and combustion efficiency is improved. The gas coupling equipment realizes effective utilization of pyrolysis gas and gasified gas, and further improves the energy recovery rate. And the gas recovery equipment ensures the maximum recovery of heat and reduces the energy consumption. The whole system not only solves the problem of sludge treatment, but also promotes cyclic utilization of resources, and has relatively high economic and environmental benefits.

Description

Technical Field

[0001] The invention relates to the technical field of sludge treatment systems, in particular to a sludge pyrolysis and gasification coupled oxygen-enriched combustion system. Background Art

[0002] With the development of industrial production and society, sludge treatment and resource utilization have received increasing attention. Sludge contains a large amount of organic matter. Direct landfill or simple incineration will produce harmful substances and cause serious pollution to the environment. Traditional sludge treatment methods usually include composting, incineration, landfill, etc., but these methods often have problems such as low treatment efficiency and low resource utilization, making it difficult to meet environmental protection requirements. In addition, the water content of sludge is high, and direct combustion will generate a lot of energy consumption, so converting it into combustible gas and other usable resources has become an effective solution.

[0003] As a feasible means of sludge resource utilization, pyrolysis and gasification technology decomposes organic matter in sludge into combustible gas through high temperature, and the residual coke and a small amount of inorganic residue can be further processed and utilized. The oxygen-enriched combustion technology can improve combustion efficiency and reduce the emission of harmful substances during the combustion process. Therefore, the sludge pyrolysis and oxygen-enriched combustion coupling treatment system came into being. The system realizes efficient resource utilization of sludge through processes such as pyrolysis, gasification and oxygen-enriched combustion, and combines waste heat recovery and exhaust gas treatment devices to effectively reduce pollution emissions and improve system energy efficiency. However, the existing technology still has certain shortcomings in equipment design, pyrolysis and gasification efficiency, and oxygen-enriched combustion control.

[0004] It can be seen that designing an efficient and environmentally friendly sludge pyrolysis gasification and oxygen-enriched combustion coupling treatment system has important technical and economic significance. Summary of the invention

[0005] In order to avoid and overcome the technical problems existing in the prior art, the present invention provides a sludge pyrolysis and gasification coupled oxygen-enriched combustion system, which effectively improves the utilization efficiency of the gas and heat generated during the sludge treatment process, saves resources, and protects the environment.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A sludge pyrolysis and gasification coupled oxygen-enriched combustion system comprises a sludge storage tank for storing sludge and an air preheating machine for air preheating the sludge in the sludge storage tank, a pyrolysis chamber for pyrolyzing the air preheated sludge is arranged at the outlet of the air preheating machine, a roller crusher for crushing the residue produced by pyrolysis is arranged at the outlet of the pyrolysis chamber, a gasification chamber for gasifying the crushed residue is installed at the outlet of the roller crusher, an oxygen-enriched combustion chamber for burning the residue formed after gasification is installed at the outlet of the gasification chamber, and a gas recovery device for recovering the gas produced in the combustion process and transmitting the gas heat to the air preheating machine is installed at the gas outlet of the oxygen-enriched combustion chamber; the pyrolysis chamber, the gasification chamber and the oxygen-enriched combustion chamber are all connected to the gas coupling device, the gas coupling device can collect and couple the gas produced by the pyrolysis chamber and the gasification chamber, and can transmit the coupled gas to the oxygen-enriched combustion chamber to realize coupled combustion.

[0008] As a further solution of the present invention: the feed rate of the pyrolysis chamber is m0, and the calculation formula of m0 is as follows:

[0009]

[0010] Wherein, η represents the thermal efficiency of the pyrolysis chamber; P represents the heat power provided by the heating medium in the pyrolysis chamber; Q represents the thermal effect of the pyrolysis reaction occurring in the pyrolysis chamber.

[0011] As a further solution of the present invention: the gas coupling device includes a first fan, a second fan and an oxygen generator; the air suction port of the first fan is connected to the air outlet of the pyrolysis chamber, and the air outlet of the first fan is connected to the first air outlet of the oxygen generator through a first three-way valve, and the air outlet of the first three-way valve is connected to the air inlet of the gasification chamber; the air suction port of the second fan is connected to the air outlet of the gasification chamber, and the air outlet of the second fan is connected to the second air outlet of the oxygen generator through a second three-way valve, and the air outlet of the second three-way valve is connected to the air inlet of the oxygen-enriched combustion chamber.

[0012] As a further solution of the present invention: the gas recovery equipment includes a boiler for absorbing the heat of the gas discharged from the oxygen-enriched combustion chamber, and the gas outlet of the boiler is successively equipped with a dust removal device for removing dust from the flue gas and a desulfurization device for desulfurizing the gas after the dust removal, and the gas outlet of the desulfurization device is connected to the air inlet of the air preheater.

[0013] As a further solution of the present invention: a fourth fan for accelerating the flow of flue gas is arranged between the boiler and the dust removal device.

[0014] As a further solution of the present invention: a residue collection area for receiving the residue after combustion is arranged at the discharge port of the oxygen-enriched combustion chamber, and a third fan for blowing the heat emitted by the residue into the boiler is arranged at the residue collection area.

[0015] As a further solution of the present invention: a chimney is installed in communication with the air outlet of the wind preheater, and a fifth fan is used between the chimney and the air outlet to accelerate the flow of gas.

[0016] As a further solution of the present invention, materials are fed between the air preheater and the pyrolysis chamber via a conveyor belt.

[0017] As a further solution of the present invention: a power generation device for generating electricity by the steam principle is also installed at the boiler.

[0018] As a further solution of the present invention: temperature sensors are installed in the pyrolysis chamber, the gasification chamber and the oxygen-enriched combustion chamber.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention realizes efficient, environmentally friendly and resourceful sludge treatment through an integrated design. From sludge storage to final gas recovery and heat energy reuse, the entire process is closely linked to form a closed-loop system. The wind turbine preheats the sludge to improve the pyrolysis efficiency, and the roller crusher ensures that the residue particle size is uniform, which is conducive to gasification. The combination of gasification and oxygen-enriched combustion not only reduces pollution emissions, but also improves combustion efficiency. The gas coupling equipment realizes the effective utilization of pyrolysis gas and gasification gas, further improving the energy recovery rate. The gas recovery equipment ensures the maximum recovery of heat and reduces energy consumption. The entire system not only solves the problem of sludge treatment, but also promotes the recycling of resources, with high economic and environmental benefits.

[0021] 2. The present invention can dynamically adjust the input amount of sludge according to the actual operating conditions through the accurate calculation formula of the pyrolysis chamber feed rate, ensuring the efficient and stable operation of the pyrolysis process. The calculation formula of the pyrolysis chamber feed rate comprehensively considers the thermal efficiency of the pyrolysis chamber, the heat power provided by the heating medium, and the thermal effect of the pyrolysis reaction, making the system operation more scientific and reasonable, and avoiding the problem of insufficient pyrolysis or waste of resources caused by excessive or insufficient feed.

[0022] 3. The gas coupling device realizes the effective collection and mixing of pyrolysis gas and gasification gas through the setting of the first and second fans and the flexible regulation of the three-way valve. At the same time, it is connected to the oxygen generator to provide a stable gas source for oxygen-enriched combustion. This design not only simplifies the gas treatment process, but also improves the gas utilization rate and combustion efficiency, and enhances the flexibility and reliability of the system.

[0023] 4. The gas recovery equipment effectively recovers the heat of the gas discharged from the oxygen-enriched combustion chamber through the series connection of the boiler, dust removal device and desulfurization device, and removes dust and desulfurizes the flue gas to ensure the cleanliness of the exhaust gas.

[0024] 5. The fourth fan is installed between the boiler and the dust removal device to speed up the flow rate of the flue gas, improve the flue gas treatment efficiency, ensure the normal operation of the dust removal and desulfurization devices, and also reduce the residence time of the flue gas in the pipeline and reduce the risk of secondary generation of pollutants.

[0025] 6. A third fan is installed at the outlet of the oxygen-enriched combustion chamber to blow the heat emitted by the residue into the boiler, further recovering the waste heat of the system, improving the overall energy utilization efficiency, and also reducing the energy loss during the residue cooling process.

[0026] 7. The fifth fan is installed at the outlet of the preheater to accelerate the flow of gas and ensure that the preheated sludge can smoothly enter the pyrolysis chamber. It also helps to maintain the dynamic balance of gas in the system and improve the operating stability and processing efficiency of the system.

[0027] 8. The conveyor belt is used for feeding, which realizes the continuous and stable transportation of sludge from the air-cooled preheater to the pyrolysis chamber, improves the automation degree of the system, reduces manual operation and reduces operating costs.

[0028] 9. Installing a power generation device at the boiler and using the steam principle to generate electricity realizes the cascade utilization of energy, further improves the energy utilization efficiency of the system, and also provides additional power supply for the system, enhancing the self-sufficiency of the system.

[0029] 10. Temperature sensors are installed in the pyrolysis chamber, gasification chamber and oxygen-enriched combustion chamber to monitor the temperature changes in each area in real time, providing important data support for the precise control and fault warning of the system, ensuring the safe and stable operation of the system. At the same time, it also provides a scientific basis for the optimization and adjustment of the system, which helps to improve the overall processing efficiency and energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 Schematic diagram of the internal structure of the pyrolysis chamber in the present invention.

[0032] Figure 3 Schematic diagram of the internal structure of the gasification chamber in the present invention.

[0033] Figure 4 It is a schematic structural diagram of the coke chamber in the present invention.

[0034] In the figure: 1. sludge storage tank; 2. air-cooled preheater; 3. conveyor belt; 4. pyrolysis chamber; 41. inclined partition; 5. roller crusher; 6. gasification chamber; 7. oxygen-enriched combustion chamber; 8. gas coupling equipment; 81. first fan; 82. second fan; 83. oxygen generator; 9. gas recovery equipment; 91. boiler; 92. power generation device; 93. fourth fan; 95. dust removal device; 96. desulfurization device; 97. third fan; 10. residue collection area; 11. fifth fan; 12. chimney; 13. coke chamber; 131. hollow cube; 132. inclined upper partition; 133. inclined lower partition; 134. air cannon. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1 to Figure 4 In the embodiment of the present invention, a sludge pyrolysis gasification and oxygen-enriched combustion coupling treatment system is provided. The system maximizes the conversion efficiency of organic matter in the sludge through optimized pyrolysis, gasification, oxygen-enriched combustion, and waste heat recovery processes, while effectively reducing the emission of pollutants, thereby achieving environmental protection and resource-based treatment of sludge. The system includes an oxygen generator 83, a sludge storage tank 1, a wind-preheated machine 2, a conveyor belt 3, a pyrolysis chamber 4, a gasification chamber 6, an oxygen-enriched combustion chamber 7, a roller crusher 5, a coke chamber 13, a residue collection area 10, a boiler 91, a power generation device 92, a dust removal device 95, a desulfurization device 96, a fan, a temperature sensor, and a chimney 12.

[0037] The specific implementation process of the present invention is as follows:

[0038] The sludge is transported from the sludge storage tank 1 to the air-cooled preheating chamber in the air-cooled preheating machine 2 , and the flue gas discharged from the boiler 91 is used to air-dry and preheat the sludge.

[0039] The air-dried and preheated sludge is sent to the pyrolysis chamber 4 through the conveyor belt 3. The pyrolysis chamber 4 is a structure with a wide top and a narrow bottom. An inclined partition 41 is arranged inside to prevent the sludge from accumulating and clogging at the feed inlet, and at the same time prolong the residence time of the sludge in the pyrolysis chamber 4. A temperature sensor is installed in the pyrolysis chamber 4. When the temperature is lower than 300°C, the heater is started to maintain the temperature of the pyrolysis chamber 4 between 300-500°C to ensure the smooth progress of the pyrolysis reaction. At this time, the moisture and volatile organic matter such as organic acids and alcohols in the sludge decompose, releasing water vapor and volatile gases such as methane and carbon dioxide, and the pyrolysis gas is discharged from the outlet at the top of the pyrolysis furnace. The mass and volume of the sludge after pyrolysis are reduced by more than 25%, and the residual coke and residue are discharged from the outlet at the bottom of the pyrolysis furnace and enter the roller crusher 5.

[0040] The roller crushing area of ​​the roller crusher 5 is a cubic structure, with 8 crushing rollers installed in the center to reduce the size of the coke and residue after pyrolysis, ensuring that they can be fully gasified after entering the gasification chamber 6, while isolating the pyrolysis chamber 4 and the gasification chamber 6 to reduce gas circulation and temperature transfer.

[0041] The gasification chamber 6 is arranged below the roller crusher 5, and the crushed coke and residue enter the gasification chamber 6. An inclined slide plate and a temperature sensor are arranged in the gasification chamber 6 to increase the residence time of the coke and residue, and adjust the temperature of the gasification chamber 6 at the same time. When the temperature of the gasification chamber 6 is lower than 600°C, the heater is started to control the temperature at 600-800°C, promoting the decomposition of organic matter to generate hydrogen, methane, carbon monoxide and other combustible gases. The coke further reacts with the gas at high temperature to generate more combustible gases. 25-30% oxygen-rich gas is introduced into the gasification chamber 6 to accelerate the gasification reaction. The gas discharged from the top outlet of the pyrolysis furnace is extracted by the first fan 81 in the gas coupling device 8, mixed with the oxygen-rich gas generated by the oxygen generator 83, and then heated by the heater before entering the gasification chamber 6, thereby increasing the heating rate of the gasification chamber 6 and reducing the concentration of pollutants such as nitrogen oxides.

[0042] After gasification is completed, the residues are mainly coke and sludge residues, and their mass and volume are reduced to 40-50% of the original amount. These residues enter the coke chamber 13 through the lower outlet of the gasification chamber 6, and the generated gasification gas such as carbon monoxide and hydrogen enters the second fan 82 from the outlet above the gasification chamber 6, and is extracted by the second fan 82 and mixed with 30-40% oxygen-enriched gas, and then enters the oxygen-enriched combustion chamber 7.

[0043] The coke chamber 13 includes a hollow cube 131. The feed port of the hollow cube 131 is provided with two flippable inclined upper partitions 132. The inclined upper partitions 132 are flipped, matched or misaligned to open and close the feed port of the hollow cube 131, so that coke and residue enter the hollow cube 131. The discharge port of the hollow cube 131 is provided with two flippable inclined lower partitions 133. The inclined lower partitions 133 are flipped, matched or misaligned to open and close the discharge port of the hollow cube 131, so that coke and residue slide out of the hollow cube 131. The inclined lower baffle 133 is equipped with a pressure sensor. When the coke chamber 13 is saturated, the two inclined upper baffles 132 turn up and close together to close the feed port of the coke chamber 13. At this time, the two inclined lower baffles 133 turn down to open the discharge port of the coke chamber 13, so that the coke and residue slide into the oxygen-enriched combustion chamber 7 to achieve quantitative combustion. At the same time, in order to enable the coke and residue to slide smoothly along the inclined lower baffle 133, an air cannon 134 is set in the hollow cube 131. The air cannon 134 promotes the sliding speed of the coke and residue along the inclined lower baffle 133, so as to assist in transporting the coke and residue to the oxygen-enriched combustion chamber 7.

[0044] In the oxygen-enriched combustion chamber 7, gasification gas and oxygen-enriched gas are used as fuels for heating. The temperature of the oxygen-enriched combustion chamber 7 is controlled at 900-1100°C, and the temperature sensor monitors in real time. When the temperature is lower than 900°C, the burner starts. At this temperature, the residual coke is fully burned to release a large amount of heat energy, achieving efficient combustion and reducing the emission of harmful substances such as carbon monoxide; at the same time, the high temperature environment accelerates the treatment of harmful components such as nitrogen oxides and carbon dioxide in the exhaust gas, reducing pollution. The mass and volume of the remaining sludge in the oxygen-enriched combustion chamber 7 are reduced to 5-10%, and the residue is discharged from the discharge port at the bottom of the oxygen-enriched combustion chamber 7 and enters the residue collection area 10.

[0045] At the front section of the residue collection area 10, conventional air is blown in by the third fan 97 in the gas recovery device 9. After the air exchanges heat with the high-temperature residue, it enters the boiler 91 together with the high-temperature flue gas generated by combustion, driving the power generation device 92 to generate electricity. The residue after heat exchange is discharged through the spiral slag conveyor. The flue gas discharged from the boiler 91 passes through the fourth fan 93 in turn and enters the dust removal device 95 and the desulfurization device 96 to control the outlet dust content to be less than 10mg / m 3 , sulfur dioxide concentration is less than 30mg / m 3 After that, the flue gas flows into the sludge air preheating chamber, and the heat of the flue gas is used to preliminarily dehydrate, air dry and preheat the sludge, so that the sludge temperature rises to 150-200° C. The treated flue gas is finally discharged from the chimney 12 through the fifth fan 11.

[0046] During the entire treatment process, the feed rate m0kg / s of the pyrolysis chamber 4 is calculated based on the pyrolysis demand. The feed rate satisfies the heat balance formula Qm0=ηP, and the calculation formula for m0 is as follows:

[0047]

[0048] Wherein, η represents the thermal efficiency of the pyrolysis chamber 4; P represents the heat power provided by the heating medium in the pyrolysis chamber 4, and the unit is W; Q represents the thermal effect of the pyrolysis reaction occurring in the pyrolysis chamber 4, and the unit is J / kg.

[0049] In the actual treatment process, the sludge moisture content and pyrolysis requirements must be taken into account, and the comprehensive adjustment coefficient K needs to be introduced to correct the feed rate. K is affected by factors such as sludge moisture content, pyrolysis temperature, and pyrolysis time. The corrected feed rate m1 = Km0.

[0050] A calculation example of the present invention: the initial mass M1 of the sludge is 5000 kg, the moisture content w1 is 80%; the parameters of the pyrolysis chamber 4: the thermal effect Q of the pyrolysis reaction is 2.5×10 6 J / kg, the thermal efficiency η is 0.75, and the heat power P provided by the heating medium is 2×10 5 W; Target setting: The moisture content w2 of the sludge is reduced to 20%, and the pyrolysis process takes t 10h.

[0051] Therefore, m0 is calculated as follows:

[0052]

[0053] Through preliminary experiments and data analysis, it is determined that under the current sludge moisture content and pyrolysis conditions, the comprehensive adjustment coefficient K = 0.8, and the corrected feed rate m1 is calculated as follows:

[0054] m1=Km0=0.8×0.06=0.048kg / s

[0055] It can be seen that the current feed rate of the pyrolysis chamber 4 is 0.048 kg / s.

[0056] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A sludge pyrolysis and gasification coupled oxygen-enriched combustion system, characterized in that: The invention comprises a sludge storage tank (1) for storing sludge and an air preheating machine (2) for performing air preheating on the sludge in the sludge storage tank (1); a pyrolysis chamber (4) for performing pyrolysis on the sludge after air preheating is arranged at the outlet of the air preheating machine (2); a roller crusher (5) for crushing the residue produced by pyrolysis is arranged at the outlet of the pyrolysis chamber (4); a gasification chamber (6) for gasifying the crushed residue is installed at the outlet of the roller crusher (5); and a gasification chamber (6) for gasifying the residue produced after gasification is installed at the outlet of the gasification chamber (6). An oxygen-enriched combustion chamber (7) is provided for carrying out combustion, and a gas recovery device (9) is installed at the gas outlet of the oxygen-enriched combustion chamber (7) for recovering the gas generated during the combustion process and transferring the gas heat to the wind-intercooling engine (2); the pyrolysis chamber (4), the gasification chamber (6) and the oxygen-enriched combustion chamber (7) are all connected to a gas coupling device (8), and the gas coupling device (8) can collect and couple the gas generated by the pyrolysis chamber (4) and the gasification chamber (6), and can transmit the coupled gas to the oxygen-enriched combustion chamber (7) to achieve coupled combustion.

2. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 1 is characterized in that: The feed rate of the pyrolysis chamber (4) is m0, and the calculation formula of m0 is as follows: In the formula, η represents the thermal efficiency of the pyrolysis chamber (4); P represents the heat power provided by the heating medium in the pyrolysis chamber (4); and Q represents the thermal effect of the pyrolysis reaction occurring in the pyrolysis chamber (4).

3. A sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 1 or 2, characterized in that: The gas coupling device (8) comprises a first fan (81), a second fan (82) and an oxygen generator (83); the air suction port of the first fan (81) is connected to the air outlet of the pyrolysis chamber (4), and the air outlet of the first fan (81) is connected to the first air outlet of the oxygen generator (83) through a first three-way valve, and the air outlet of the first three-way valve is connected to the air inlet of the gasification chamber (6); the air suction port of the second fan (82) is connected to the air outlet of the gasification chamber (6), and the air outlet of the second fan (82) is connected to the second air outlet of the oxygen generator (83) through a second three-way valve, and the air outlet of the second three-way valve is connected to the air inlet of the oxygen-enriched combustion chamber (7).

4. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 3 is characterized in that: The gas recovery device (9) comprises a boiler (91) for absorbing the heat of the gas discharged from the oxygen-enriched combustion chamber (7). A dust removal device (95) for removing dust from the flue gas and a desulfurization device (96) for desulfurizing the gas after the dust removal are installed in sequence at the gas outlet of the boiler (91). The gas outlet of the desulfurization device (96) is connected to the gas inlet of the wind-preheating machine (2).

5. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 4 is characterized in that: A fourth fan (93) is also arranged between the boiler (91) and the dust removal device (95) to accelerate the flow of smoke.

6. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 5, characterized in that: A residue collection area (10) for receiving residues after combustion is arranged at the discharge port of the oxygen-enriched combustion chamber (7), and a third fan (97) for blowing heat emitted by the residues into the boiler (91) is arranged at the residue collection area (10).

7. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 6, characterized in that: A chimney (12) is installed in communication with the air outlet of the wind preheater (2), and a fifth fan (11) is provided between the chimney (12) and the air outlet to accelerate the flow of gas.

8. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 7, characterized in that: The conveyor belt (3) is used to transport materials between the air preheater and the pyrolysis chamber (4).

9. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 8, characterized in that: The boiler (91) is also provided with a power generation device (92) for generating electricity by the steam principle.

10. The sludge pyrolysis and gasification coupled oxygen-enriched combustion system according to claim 9, characterized in that: Temperature sensors are installed in the pyrolysis chamber (4), the gasification chamber (6) and the oxygen-enriched combustion chamber (7).

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