Sludge carbonization treatment system

Abstract

The utility model discloses a sludge carbonization treatment system which comprises a sludge temporary storage tank, a plate-and-frame filter press, a drying machine, a continuous anaerobic pyrolysis carbonization furnace, cooling equipment and a carbon residue storage bin, the sludge temporary storage tank is used for temporarily storing sludge, the top of the sludge temporary storage tank is communicated with the medicament adding equipment, an output port of the sludge temporary storage tank is communicated with the plate-and-frame filter press, the sludge is subjected to solid-liquid separation through the plate-and-frame filter press, the sludge outlet end of the plate-and-frame filter press is communicated with the drying machine, and the dewatered sludge is dried through the drying machine; the output end of the drying machine is communicated with the continuous anaerobic pyrolysis carbonization furnace, the dried sludge is conveyed to the continuous anaerobic pyrolysis carbonization furnace, the sludge is subjected to a pyrolysis carbonization reaction to generate sludge carbon and pyrolysis gas, and the sludge output end of the continuous anaerobic pyrolysis carbonization furnace is communicated with the cooling equipment. The sludge carbonization treatment efficiency is improved, energy consumption is reduced, effective utilization of pyrolysis gas is achieved, environmental pollution is reduced, and meanwhile the stability and economical efficiency of system operation are improved.

Description

Technical Field

[0001] This utility model relates to the field of sludge carbonization treatment, specifically to a sludge carbonization treatment system. Background Technology

[0002] The main reasons for carbonizing sludge are as follows:

[0003] Achieving volume reduction: Sludge has a high water content and large volume. Carbonization can remove a large amount of water, which greatly reduces the volume of sludge. For example, the sludge carbonization project in Jimo, Qingdao, has a volume reduction rate of over 90%, which facilitates subsequent transportation and treatment.

[0004] Achieving harmlessness: The high-temperature environment of the carbonization process can effectively kill pathogens, parasite eggs and other harmful microorganisms in the sludge, while converting heavy metals into a residual state, reducing biological toxicity and preventing their release and precipitation in nature. For example, the sludge biochar of the Jimo project was tested and found to have heavy metal leaching toxicity far better than the standard limit.

[0005] Resource recovery: Carbonized sludge has multiple uses. It can be used as a soil conditioner to adjust soil pH and improve compacted soil. It can also be used as a raw material for brick making, processed into slow-release fertilizer, and as a roadbed material for sponge cities. In addition, it can be used as an adsorbent and fuel, thus realizing the recycling of resources.

[0006] Reduced energy consumption and costs: The combustible gas produced during the carbonization process can be used to provide the heat required for carbonization, reducing external energy consumption and lowering operating costs.

[0007] Reduce environmental pollution: Effectively control the generation of harmful substances such as dioxins and reduce greenhouse gas emissions. Compared with other treatment methods, such as direct landfill or untreated stockpiling, it poses a lower risk of environmental pollution.

[0008] Meanwhile, with the acceleration of industrialization and urbanization, the production of sewage sludge has increased dramatically. Sludge has a complex composition, containing not only large amounts of organic matter and heavy metals, but also potentially carrying pathogens and other harmful substances. If not properly treated, it will cause serious pollution to the soil, water bodies, and atmospheric environment, threatening ecological balance and human health.

[0009] Traditional sludge treatment methods, such as landfill, incineration, and composting, all have certain limitations. Landfill requires a large amount of land resources and may lead to groundwater pollution; while incineration can reduce sludge volume and render it harmless, it produces toxic and harmful gases such as dioxins, causing secondary pollution to the environment; composting has high requirements for sludge composition and treatment processes, limiting its applicability. Against this backdrop, sludge carbonization technology has gradually attracted attention. Sludge carbonization can convert sludge into sludge char and pyrolysis gas through anaerobic pyrolysis at relatively low temperatures. Sludge char can be used in soil improvement, adsorbent preparation, and other fields, achieving resource recycling; pyrolysis gas can be used as an energy source, improving the economic efficiency of sludge treatment. However, existing sludge carbonization systems still have many problems in practical applications. For example, the high moisture content of sludge before carbonization directly affects carbonization efficiency and energy consumption; if the pyrolysis gas generated during carbonization is not effectively utilized, it will cause energy waste and environmental pollution; at the same time, the overall operational stability and treatment cost of the system need further optimization.

[0010] To address the aforementioned issues, this invention proposes a novel sludge carbonization treatment system, aiming to improve sludge carbonization treatment efficiency, reduce energy consumption, achieve effective utilization of pyrolysis gas, reduce environmental pollution, and simultaneously enhance the stability and economy of system operation. Utility Model Content

[0011] Therefore, in order to overcome the above-mentioned shortcomings, this utility model provides a sludge carbonization treatment system, which improves the efficiency of sludge carbonization treatment, reduces energy consumption, realizes the effective utilization of pyrolysis gas, reduces environmental pollution, and at the same time improves the stability and economy of system operation.

[0012] This invention is implemented by constructing a sludge carbonization treatment system, characterized in that: the system comprises a sludge temporary storage tank, a plate and frame filter press, a dryer, a continuous anaerobic pyrolysis carbonization furnace, cooling equipment, and a carbon residue storage bin; the sludge temporary storage tank is used to temporarily store sludge, and its top is connected to a reagent addition device for adding sludge conditioning and dewatering agents; the outlet of the sludge temporary storage tank is connected to the plate and frame filter press for solid-liquid separation, reducing the sludge moisture content to a minimum. 60% of the sludge is discharged from the plate and frame filter press and connected to a dryer. The dryer dries the dewatered sludge to reduce its moisture content to below 20%. The output of the dryer is connected to the continuous anaerobic pyrolysis carbonization furnace. The dried sludge is then transported to the furnace and indirectly heated at 500-650°C to induce a pyrolysis carbonization reaction, producing sludge char and pyrolysis gas. The output of the furnace is connected to a cooling device, and the output of the cooling device is connected to a carbon slag storage bin. After cooling, the sludge is sent to the carbon slag storage bin.

[0013] According to the present invention, a sludge carbonization treatment system is characterized in that: the system further comprises a pyrolysis gas combustion device, the pyrolysis gas outlet of the continuous anaerobic pyrolysis carbonization furnace is connected to the pyrolysis gas combustion device, the high-temperature flue gas outlet of the pyrolysis gas combustion device is connected back to the continuous anaerobic pyrolysis carbonization furnace, the pyrolysis gas generated during carbonization enters the pyrolysis gas combustion device, generates flue gas at 800-900°C, and returns to the carbonization furnace to provide heat for pyrolysis carbonization.

[0014] According to the present invention, a sludge carbonization treatment system is characterized in that: the high-temperature flue gas outlet of the pyrolysis gas combustion device is simultaneously connected to the dryer; the tail gas of the dryer is connected to the flue gas treatment system, and the flue gas temperature from the pyrolysis furnace is about 600°C. It is first used for sludge drying, and after drying, the flue gas temperature drops to 120°C before entering the flue gas treatment system. After being treated by processes such as denitrification, desulfurization, and dust removal, it meets the emission standards.

[0015] According to the present invention, a sludge carbonization treatment system is characterized in that it further includes a steam waste heat boiler, and the dryer is also connected to the steam waste heat boiler for indirect heating using the steam generated by the steam waste heat boiler.

[0016] According to the present invention, a sludge carbonization treatment system is characterized in that the wastewater outlet end of the plate and frame filter press 2 is connected to a wastewater temporary storage tank.

[0017] This utility model has the following advantages: (1) High-efficiency sludge pretreatment: By connecting the agent addition device at the top of the sludge storage tank, conditioning and dehydration agents are added to the sludge. Combined with the plate and frame filter press and dryer, the sludge moisture content can be gradually reduced from the initial state to below 20%. This efficient pretreatment process greatly improves the efficiency of subsequent carbonization treatment and reduces the problems of prolonged carbonization time and increased energy consumption caused by high moisture content. (2) Recycling of pyrolysis gas: The system is equipped with a pyrolysis gas combustion device. After the pyrolysis gas generated by carbonization enters the device, it generates high-temperature flue gas of 800-900℃. This flue gas not only returns to the continuous anaerobic pyrolysis carbonization furnace to provide heat for the pyrolysis carbonization reaction, but also is simultaneously transported to the dryer. The recycling of pyrolysis gas realizes the cascade utilization of energy, significantly reduces the overall energy consumption of the system, improves the energy utilization efficiency, and reduces the dependence on external energy. (3) Waste heat recovery and utilization: The dryer is connected to the steam waste heat boiler. The steam generated by the steam waste heat boiler is used for indirect heating, which further improves the comprehensive utilization efficiency of energy. Meanwhile, the flue gas at around 600°C from the pyrolysis furnace is first used for sludge drying, and the flue gas cooled to 120°C after drying enters the flue gas treatment system. This waste heat recovery method saves energy and reduces energy consumption costs in the drying process. (4) Significant environmental benefits: On the one hand, the effective use of pyrolysis gas reduces the pollution caused by its direct emissions to the environment; on the other hand, the exhaust gas from the dryer is connected to the flue gas treatment system and is discharged in compliance with standards after being treated by processes such as denitrification, desulfurization, and dust removal, avoiding secondary pollution of the environment by toxic and harmful gases such as dioxins generated in the traditional sludge treatment process. In addition, the wastewater generated by the plate and frame filter press is centrally treated through a wastewater storage tank, preventing the pollution of the water environment by the random discharge of wastewater and comprehensively improving the environmental performance of the system. (5) Stable system operation: The equipment is closely connected and works in coordination, forming a stable processing flow from sludge storage, pretreatment, carbonization to product cooling and storage. The continuous anaerobic pyrolysis carbonization furnace ensures the continuity and stability of the carbonization process. The cooling equipment and carbon slag storage bins effectively handle the carbonized products. The entire system operates stably and reliably, reducing maintenance costs and operational risks. (6) Resource recycling: The sludge carbon produced after carbonization can be used in soil improvement, adsorbent preparation and other fields, realizing the resource recycling of sludge, providing valuable raw materials for related industries, and reducing the exploitation of new resources, which has good economic and social benefits. Attached Figure Description

[0018] Figure 1 This is an implementation structural diagram of the sludge carbonization treatment system of this application.

[0019] The system includes: 1. Sludge temporary storage tank; 2. Plate and frame filter press; 3. Dryer; 4. Continuous anaerobic pyrolysis carbonization furnace; 5. Cooling equipment; 6. Carbon residue storage silo; 7. Reagent addition equipment; 8. Pyrolysis gas combustion device; 9. Flue gas treatment system; 10. Steam waste heat boiler; and 11. Sewage temporary storage tank. Detailed Implementation

[0020] The following will be combined with the appendix Figure 1 This utility model will be described in detail, and the technical solutions in the embodiments of this utility model will be clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0021] This utility model provides a sludge carbonization treatment system, such as Figure 1 As shown, the system can be implemented as follows: The system comprises a sludge storage tank 1, a plate and frame filter press 2, a dryer 3, a continuous anaerobic pyrolysis carbonization furnace 4, a cooling device 5, and a carbon residue storage bin 6. The sludge storage tank 1 is used to temporarily store sludge. The top of the sludge storage tank 1 is connected to a reagent addition device 7, through which sludge treatment agents for conditioning and dewatering the sludge are added to the sludge storage tank 1. The outlet of the sludge storage tank 1 is connected to the plate and frame filter press 2, which performs solid-liquid separation on the sludge, reducing the sludge moisture content to 60%. The sludge outlet of the filter press 2 is connected to the dryer 3, which dries the dewatered sludge to reduce its moisture content to below 20%. The output of the dryer 3 is connected to the continuous anaerobic pyrolysis carbonization furnace 4, which transports the dried sludge to the furnace. The sludge is indirectly heated at 500-650°C to induce a pyrolysis carbonization reaction, producing sludge char and pyrolysis gas. The sludge outlet of the continuous anaerobic pyrolysis carbonization furnace 4 is connected to the cooling device 5, and the output of the cooling device 5 is connected to the carbon slag storage bin 6. After cooling, the sludge is sent to the carbon slag storage bin 6.

[0022] In this application, the system also includes a pyrolysis gas combustion device 8. The pyrolysis gas outlet of the continuous oxygen-free pyrolysis carbonization furnace 4 is connected to the pyrolysis gas combustion device 8. The high-temperature flue gas outlet of the pyrolysis gas combustion device 8 is connected back to the continuous oxygen-free pyrolysis carbonization furnace 4. The pyrolysis gas generated during carbonization enters the pyrolysis gas combustion device to generate flue gas at 800-900°C, which is then returned to the carbonization furnace to provide heat for pyrolysis carbonization.

[0023] In this application, the high-temperature flue gas outlet of the pyrolysis gas combustion device 8 is simultaneously connected back to the dryer 3; the tail gas of the dryer 3 is connected to the flue gas treatment system 9. The flue gas temperature from the pyrolysis furnace is about 600°C. It is first used for sludge drying. After drying, the flue gas temperature drops to 120°C and then enters the flue gas treatment system. After being treated by processes such as denitrification, desulfurization, and dust removal, it meets the emission standards.

[0024] This application also includes a steam waste heat boiler 10, and the dryer 3 is also connected to the steam waste heat boiler 10 for indirect heating using the steam generated by the steam waste heat boiler 10.

[0025] In this application, the wastewater outlet end of the plate and frame filter press 2 is connected to the wastewater temporary storage tank 11.

[0026] The sludge carbonization process of this application is described in detail below, including the following operations:

[0027] Collection and storage: Sludge with a moisture content of about 80% is collected using specialized sealed vehicles and transported to the treatment plant. After being transported, it is stored in a closed sludge temporary storage area according to its source and arrival time.

[0028] Conditioning and dewatering: Adding agents to the sludge breaks down the cell walls of the sludge, and then using equipment such as plate and frame filter presses to separate solids and liquids, reducing the sludge moisture content to about 60%.

[0029] Drying: The dewatered sludge is sent to a dryer and brought into contact with the waste heat flue gas discharged from the carbonization furnace, or indirectly heated by steam generated by a waste heat boiler, so that the moisture content of the sludge is reduced to below 20%.

[0030] Pyrolysis carbonization: The dried sludge is transported to a continuous anaerobic pyrolysis carbonization furnace and indirectly heated at a temperature of 500-650℃ to cause the sludge to undergo a pyrolysis carbonization reaction, producing sludge char and pyrolysis gas.

[0031] Combustion and heating: The pyrolysis gas produced by carbonization enters the pyrolysis gas combustion device, producing flue gas at 800-900℃, which is returned to the carbonization furnace to provide heat for pyrolysis and carbonization.

[0032] Cooling and storage: After carbonization, the sludge char is discharged from the carbonization furnace, cooled, and sent to the char slag storage silo.

[0033] Exhaust gas treatment: After the pyrolysis gas produced by the pyrolysis carbonization furnace is burned, the flue gas temperature coming out of the pyrolysis furnace is about 600℃. It is first used for sludge drying. After drying, the flue gas temperature drops to 120℃ and then enters the flue gas treatment system. After being treated by processes such as denitrification, desulfurization and dust removal, it meets the emission standards.

[0034] The chemicals added during sludge conditioning mainly fall into the following categories:

[0035] (a) Flocculants:

[0036] Inorganic flocculants:

[0037] Aluminum sulfate: Hydrolysis produces aluminum hydroxide colloids, which cause sludge particles to coagulate through double-layer compression and adsorption bridging. It is suitable for sludge with a pH of 6-7.5 and has good effects in treating sludge from dyeing and printing wastewater.

[0038] Polyaluminum chloride (PAC): It has advantages such as good flocculation effect and fast settling speed. It can adapt to a wide pH range, generally between 5 and 9. It is widely used in the conditioning of sludge from various industrial wastewaters and domestic sewage.

[0039] Ferric chloride: Its hydrolysis products effectively compress the electric double layer of sludge particles, resulting in high floc density and good settling performance. It is suitable for sludge with a pH of 6-8, and has a significant conditioning effect on sludge with high turbidity and high organic matter content.

[0040] Organic flocculants:

[0041] Polyacrylamide (PAM) is classified into cationic, anionic, and nonionic types. Cationic PAM is suitable for negatively charged sludge particles, causing sludge to coagulate through charge neutralization and adsorption bridging, and is often used for conditioning municipal sewage sludge. Anionic PAM is generally used to treat sludge containing a large number of inorganic particles. Nonionic PAM is suitable for sludge with a neutral pH.

[0042] (ii) Coagulant aid:

[0043] Quicklime: It can adjust the pH value of sludge, change the surface charge of sludge particles, promote the binding of flocculants with sludge particles, and increase the floc strength and settling performance of sludge. It is commonly used for conditioning industrial wastewater sludge, especially highly acidic sludge.

[0044] Activated silica: It is an inorganic polymeric coagulant that can improve the strength and settling speed of flocs. When used in combination with flocculants such as aluminum salts and iron salts, it can enhance the flocculation effect of sludge and is suitable for conditioning various types of sludge.

[0045] (III) Conditioning agents:

[0046] Ferric aluminum chloride combines the advantages of aluminum and iron salts, exhibiting excellent flocculation and sedimentation properties. It performs exceptionally well in treating sludge with complex components, such as chemical wastewater sludge.

[0047] Polyferric sulfate: The polynuclear hydroxy iron ions produced by hydrolysis can effectively remove organic matter and heavy metal ions from sludge. It has a good conditioning effect on sludge in industries such as printing and dyeing and electroplating, and can adapt to a pH range of 4-11.

[0048] Polymeric aluminum ferric sulfate: Combining the advantages of aluminum salts, iron salts and silicates, it has high flocculation performance and good stability, and has a good conditioning effect on sludge of different properties, effectively reducing the moisture content of sludge.

[0049] (iv) Other medicines:

[0050] Oxidizing agents, such as potassium permanganate and hydrogen peroxide, can destroy the organic structure in sludge through oxidation, destabilize colloidal particles in sludge, and improve the dewatering performance of sludge. They are often used to treat sludge containing recalcitrant organic matter.

[0051] Acid-base regulators: Sulfuric acid, hydrochloric acid, etc. are used to lower the pH value of sludge, while sodium hydroxide, sodium carbonate, etc. are used to raise the pH value of sludge. By adjusting the pH value, the properties of sludge are improved, creating favorable conditions for flocculants to function.

[0052] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sludge carbonization treatment system characterized by; The system is composed of a sludge temporary storage tank (1), a plate-and-frame filter press (2), a dryer (3), a continuous anaerobic pyrolysis carbonization furnace (4), a cooling device (5), and a carbon residue storage bin (6). The sludge temporary storage tank (1) is used for temporarily storing sludge. The top of the sludge temporary storage tank (1) is connected to a medicament adding device (7). The output port of the sludge temporary storage tank (1) is connected to the plate-and-frame filter press (2). The sludge outlet end of the plate-and-frame filter press (2) is connected to the dryer (3). The output end of the dryer (3) is connected to the continuous anaerobic pyrolysis carbonization furnace (4). The sludge output end of the continuous anaerobic pyrolysis carbonization furnace (4) is connected to the cooling device (5). The output end of the cooling device (5) is connected to the carbon residue storage bin (6). After cooling, the sludge is sent to the carbon residue storage bin (6).

2. The sludge carbonization processing system according to claim 1, wherein The system is also composed of a pyrolysis gas combustion device (8). The pyrolysis gas outlet of the continuous anaerobic pyrolysis carbonization furnace (4) is connected to the pyrolysis gas combustion device (8). The high-temperature flue gas outlet of the pyrolysis gas combustion device (8) is connected back to the continuous anaerobic pyrolysis carbonization furnace (4).

3. The sludge carbonization system of claim 2, wherein: The high-temperature flue gas outlet of the pyrolysis gas combustion device (8) is also connected back to the dryer (3). The tail gas of the dryer (3) is connected to a flue gas treatment system (9).

4. The sludge carbonization processing system according to claim 1, wherein The system also includes a steam waste heat boiler (10). The dryer (3) is also connected to the steam waste heat boiler (10). The steam generated by the steam waste heat boiler (10) is used for indirect heating.

5. The sludge carbonization system of claim 1, wherein The sludge wastewater outlet end of the plate-and-frame filter press (2) is connected to a sludge wastewater temporary storage tank (11).

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