Lake sludge integrated in-situ disposal method and mobile platform

Abstract

The application belongs to the field of sludge treatment, and specifically discloses a lake sludge integrated in-situ disposal method and a mobile platform. The method is to suck sludge, pretreat and form and granulate the sludge to obtain material balls, then perform smoldering combustion on the material balls to obtain porous ceramic particles, and finally put the porous ceramic particles into a lake to purify water quality. The application introduces smoldering technology into lake sludge disposal, utilizes the advantage that smoldering can realize self-sustaining continuous reaction, does not need to transport sludge to land for treatment, and only relies on a small amount of heat input to dispose the material balls, and the generated porous ceramic particles can be directly put into the lake to purify water quality, thereby realizing integrated in-situ deep disposal of lake sludge.

Description

Technical Field

[0001] This application belongs to the field of sludge treatment, and more specifically, relates to an integrated on-site treatment method and mobile platform for lake sludge. Background Technology

[0002] Lake siltation refers to the accumulation of large amounts of mud and sand in a lake. As rainwater and thawing ice water flow into the lake, the cross-section widens and the flow velocity slows down, thus reducing the movement of sediment and leading to siltation. Lake siltation has increasingly affected the normal functioning of lakes in flood control, drainage, irrigation, water supply, and navigation. Therefore, lake dredging projects are essential to restore the normal functions of lakes and promote rapid and sustainable economic and social development.

[0003] Traditional lake dredging requires transporting bottom sediment to land for dewatering and harmless treatment, which consumes significant land resources, is time-consuming, and impacts the surrounding ecological environment. In addition, some new methods have been attempted for lake dredging. For example, the "Taihu Star" system is the first in China to "move" the environmentally friendly flocculant dosing system and plate and frame filter press system required for sludge solidification from land to water. It can complete the entire process from ecological dredging to impurity removal, flocculation adjustment, dewatering, volume reduction, and harmless treatment on the water. This method solves the problem of land consumption for sludge solidification to some extent, but it still cannot achieve in-situ deep treatment and reuse of sludge. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this application provides an integrated on-site treatment method and mobile platform for lake sludge, aiming to solve the problems of existing lake dredging methods occupying land resources and failing to achieve in-situ deep treatment of sludge.

[0005] According to one aspect of this application, an integrated on-site treatment method for lake silt is provided, specifically as follows: S1 pumps in sludge, pre-treats it, and shapes it into pellets to obtain material balls; S2 involves smoldering the pellets in situ to produce porous ceramic particles; S3 introduces the porous ceramic particles into the lake to purify the water.

[0006] Compared with the prior art, the above-described technical solutions conceived in this application introduce smoldering combustion technology into the treatment of lake sludge, enabling integrated on-site treatment of lake sludge without the need to transport lake sludge to land for processing, thus avoiding the occupation of land resources. Furthermore, the generated porous ceramic particles can be directly introduced into the lake, which can play a role in purifying water quality.

[0007] As a further preferred embodiment, step S1 includes the following sub-steps: S11 extracts sludge and conditions and filters it to obtain pretreated sludge; S12 The pretreated sludge is mixed with additives and then shaped and granulated to obtain pellets.

[0008] As a further preferred embodiment, in step S11, an organic conditioner and / or an inorganic conditioner are added to the sludge for conditioning, wherein the organic conditioner includes polyacrylamide, and the inorganic conditioner includes one or more of lime, fly ash, ferric chloride, and aluminum sulfate.

[0009] As a further preferred embodiment, in step S12, the additive is biomass powder and / or coal gasification slag, and the mass ratio of the pretreated sludge to the additive is 7:3 to 4:1.

[0010] As a further preferred embodiment, in step S2, the specific process of smoldering combustion is as follows: the pellets are fed into the smoldering reactor and preheated to 300°C to 400°C, then heating is stopped and air is introduced for ignition.

[0011] As a further preferred embodiment, in step S2, porous ceramic particles are prepared using either a continuous reaction or a batch reaction. When preparing porous ceramic particles using a continuous reaction, slag is discharged when the temperature of the bottom layer of the smoldering reactor is below 100°C. When preparing porous ceramic particles using a batch reaction, the reaction ends and slag is discharged when the center temperature begins to decrease or the oxygen concentration in the outlet flue gas is above 5.0 vol.%.

[0012] As a further preferred embodiment, in step S2, the preheating time is 40 min to 60 min, and the Darcy flow rate of the introduced air is 3 cm / s to 6 cm / s.

[0013] According to another aspect of this application, a mobile platform is provided for realizing the above-mentioned integrated on-site treatment method for lake sludge.

[0014] As a further preferred embodiment, the mobile platform includes a cutter suction dredger and a sludge disposal vessel. The cutter suction dredger is used to pump sludge and send it into the sludge disposal vessel. The sludge disposal vessel is used to pre-treat and granulate the sludge to obtain pellets, and then smolder the pellets to produce porous ceramic particles, which are then directly thrown into the lake.

[0015] As a further preferred embodiment, the mobile platform also includes a docking vessel for transporting river sand generated by the sludge treatment vessel for sale.

[0016] In summary, compared with the prior art, the technical solutions conceived in this application have the following main technical advantages: 1. This application addresses the problems of existing lake dredging methods, such as occupying land resources and failing to achieve in-situ deep treatment of sludge. It proposes an integrated in-situ treatment method for lake sludge, which introduces smoldering technology into the treatment of lake sludge. Taking advantage of the self-sustaining continuous reaction of smoldering, it eliminates the need to transport sludge to land for treatment. It can dehydrate and decarbonize the pellets with only a small amount of heat input. Furthermore, the resulting porous ceramic particles can be directly introduced into the lake to purify the water quality, thereby achieving integrated in-situ deep treatment of lake sludge. 2. In particular, this application optimizes the composition and ratio of additives for the special application scenario of preparing porous ceramic particles by smoldering combustion of lake silt. This enables the synergistic preparation of ceramsite from multiple wastes. On the one hand, by adding biomass powder and / or coal gasification slag, the organic matter content of the pellets is increased, so that the peak temperature of smoldering combustion reaches above 1000℃. This achieves volume and weight reduction while ensuring that the sintered porous ceramic particles have sufficient porosity and structural strength. On the other hand, the mineral components in biomass powder and coal gasification slag, such as calcium, silicon and aluminum, are used to improve the structural stability and sintering strength of the porous ceramic particles. 3. Meanwhile, the integrated on-site treatment mobile platform for lake sludge provided in this application achieves integrated treatment of river sludge and effective reduction of land area by relying on smoldering technology. The sludge treatment vessel does not need to be equipped with a drying system, which not only reduces energy consumption, but also greatly improves the space utilization rate of the equipment through a smaller footprint and a more integrated treatment process. It avoids the space limitations caused by the excessive footprint of traditional equipment and is particularly suitable for confined space environments such as lake surface treatment platforms. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of the integrated on-site treatment method for lake silt provided in the embodiments of this application; Figure 2 This is a three-dimensional schematic diagram of the mobile platform for integrated on-site treatment of lake silt provided in the embodiments of this application.

[0018] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-Cutter suction dredger, 2-Sludge treatment vessel, 21-Pretreatment assembly, 22-Filter press assembly, 23-Pelletizing assembly, 24-Smoldering reactor, 3-Connecting vessel. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] like Figure 1 As shown, this application provides an integrated on-site treatment method for lake sludge, specifically as follows: S1 pumps in sludge, pre-treats it, and shapes it into pellets to obtain material balls; S2 involves smoldering the pellets in situ to produce porous ceramic particles. S3 introduces porous ceramic particles into the lake on-site to purify the water.

[0021] This application addresses the challenges of complex, large-scale, and energy-intensive onshore sintering systems, which are unsuitable for the confined spaces of ships. Therefore, it introduces smoldering combustion technology into lake sludge treatment. Leveraging the advantages of smoldering combustion—no additional dehydration, high volume reduction rate, and thorough decontamination—it achieves a self-sustaining continuous reaction. This eliminates the need to transport sludge to land for processing and requires minimal heat input, enabling integrated on-site treatment of lake sludge and avoiding land occupation. Furthermore, the generated porous ceramic particles can be directly added to the lake, purifying the water. This solves the problems of high energy consumption, incomplete volume reduction, and the need for secondary treatment on shore in existing lake sludge treatment processes. It achieves deep volume reduction of lake sludge, co-produces porous ceramic particles, and provides on-site water purification. Moreover, it eliminates the need for large storage spaces for sludge or mud cakes on ships, enabling deep volume reduction and disposal of sludge on-site, significantly reducing costs and simplifying the treatment process.

[0022] Furthermore, step S1 includes the following sub-steps: S11 extracts and conditions the sludge, and then performs plate and frame filter press to reduce the moisture content of the sludge to about 50%, thereby obtaining pretreated sludge. S12 mixes pretreated sludge with additives and then granulates it to obtain pellets.

[0023] Furthermore, in step S11, an organic conditioner and / or an inorganic conditioner are added to the sludge for conditioning, thereby rapidly flocculating the fine particles in the sludge and improving dewatering and energy absorption. The organic conditioner includes polyacrylamide, and the inorganic conditioner includes one or more of lime, fly ash, ferric chloride, and aluminum sulfate.

[0024] Further, in step S12, the additive is biomass powder and / or coal gasification slag, and the mass ratio of pretreated sludge to additive is 7:3 to 4:1, thereby obtaining pellets with a particle size between 10 mm and 40 mm. If the additive ratio is too low, the calorific value of the raw material will be too low, resulting in an excessively low smoldering peak temperature, which will affect the strength of the ceramsite; if the additive ratio is too high, the calorific value of the raw material will be too high, which may lead to over-sintering, thus affecting the pore structure of the ceramsite. Therefore, the preferred mass ratio of pretreated sludge to additive in the smoldering reaction is 7:3 to 4:1. The biomass powder is preferably biomass with a calorific value of 2000 kcal / kg to 4000 kcal / kg, such as sawdust or rice husks.

[0025] In existing technologies, the smoldering temperature of sludge is approximately 400℃ to 600℃, primarily focusing on volume reduction. The ash residue still needs to be transported for final disposal. This application addresses this by blending additives, including biomass powder and coal gasification slag, and optimizing the blending ratio. This increases the organic matter content of the pellets, enabling the peak smoldering temperature to reach 1000℃ to 1100℃. This achieves volume and weight reduction while ensuring the sintered porous ceramic particles possess sufficient porosity and structural strength. In particular, blending raw materials with a high fixed carbon / volatile matter ratio is beneficial for achieving the target sintering temperature and ensuring continuous and stable operation. Furthermore, the calcium in the biomass powder and coal gasification slag has a fluxing effect, which helps lower the sintering temperature and improve the sintering performance of the ceramsite. The silicon and aluminum in the biomass powder and coal gasification slag can react with the metal components in the sludge at high temperatures to form silicate minerals, thereby improving the structural stability and sintering strength of the ceramsite.

[0026] Further, in step S2, the specific process of smoldering combustion is as follows: the pellets are fed into the smoldering reactor and preheated to 300℃~400℃, with a preheating time preferably 40min~60min. Then, heating is stopped and air is introduced for ignition. The Darcy flow rate of the introduced air is preferably 3cm / s~6cm / s, allowing the pellets to undergo smoldering combustion to produce porous ceramic particles. The pellets sequentially undergo drying, pyrolysis, oxidation, and gasification to finally form porous ceramic particles. The peak temperature of this process can reach 1000℃~1200℃.

[0027] When preparing porous ceramic particles using a continuous reaction, slag is discharged when the temperature of the bottom layer of the smoldering reactor is below 100°C, and new pellets are fed directly without preheating and ignition. When preparing porous ceramic particles using a batch reaction, the reaction ends and slag is discharged when the center temperature begins to decrease or the oxygen concentration in the outlet flue gas is above 5.0 vol.%, and then new pellets are fed in and reheated and ignited.

[0028] like Figure 2As shown, according to another aspect of this application, a mobile platform is provided for realizing the above-mentioned integrated on-site treatment method for lake sludge.

[0029] In a preferred embodiment of this application, the mobile platform includes a cutter suction dredger 1 and a sludge disposal vessel 2. The cutter suction dredger 1 continuously excavates and pumps sludge from the bottom of the lake using an underwater spiral cutter head, and then continuously transports the sludge to the sludge disposal vessel 2 through a sludge conveying pipeline. The sludge treatment vessel 2 is used to condition the sludge and then perform plate and frame filter press to obtain pretreated sludge with a moisture content reduced to about 50%. The pretreated sludge is mixed with additives and granulated to obtain pellets. The pellets are then sent to a smoldering reactor for dehydration and decarbonization to produce porous ceramic particles, which are then directly added to the lake for further water purification.

[0030] Preferably, the sludge treatment vessel includes a pretreatment component 21, a filter press component 22, a pelletizing component 23, and a smoldering reactor 24 connected in sequence. The pretreatment component 21 is used to pretreat the sludge, removing large particles such as sand and gravel, and adding a conditioning agent before feeding it into the filter press component 22 for filtration to obtain pretreated sludge. The pretreated sludge is mixed with additives and then granulated in the pelletizing component 23 to obtain pellets. The pellets are then dehydrated and decarbonized in the smoldering reactor 24 to produce porous ceramic particles. The smoldering reactor 24 preferably adopts a vertical structure, which can effectively save floor space and realize on-site treatment of sludge on the lake surface to prepare ceramic particles.

[0031] Furthermore, the mobile platform also includes a shuttle boat 3, which is used to transfer and transport river sand generated by the sludge treatment vessel for sale.

[0032] It should be noted that the application scenarios of the integrated on-site treatment method and mobile platform for lake silt provided in this application are not limited to lakes, but can also be used in all water systems with a large amount of silt, such as rivers and lakes.

[0033] The technical solutions provided in this application will be further described below with reference to specific embodiments.

[0034] Example 1 S1 extracts sludge and adds polyacrylamide for conditioning, then performs plate and frame filter press to obtain pretreated sludge. The pretreated sludge is mixed with coal gasification slag additives at a mass ratio of 7:3 and granulated to obtain pellets. S2 smoldering the pellets on the ship to produce porous ceramic particles. The smoldering reaction conditions are: ignition temperature of 300℃, Darcy flow rate of air of 4cm / s, and average peak temperature of 1100℃ during the smoldering reaction. S3 introduces porous ceramic particles into the lake on-site to purify the water.

[0035] Example 2 S1 extracts sludge and adds lime for conditioning, then performs plate and frame filter press to obtain pretreated sludge. The pretreated sludge is mixed with sawdust additive at a mass ratio of 3.5:1 and then granulated to obtain pellets. S2 smoldering the pellets on the ship to produce porous ceramic particles. The smoldering reaction conditions are: ignition temperature of 350℃, Darcy flow rate of air of 4.2cm / s, and average peak temperature of 1000℃. S3 introduces porous ceramic particles into the lake on-site to purify the water.

[0036] Example 3 S1 extracts sludge and adds polyacrylamide for conditioning, then performs plate and frame filter press to obtain pretreated sludge. The pretreated sludge is mixed with coal gasification slag additives at a mass ratio of 4:1 and granulated to obtain pellets. S2 smoldering the pellets on the ship to produce porous ceramic particles. The smoldering reaction conditions are: ignition temperature of 300℃, Darcy flow rate of air of 4cm / s, and average peak temperature of 1050℃ during the smoldering process. S3 introduces porous ceramic particles into the lake on-site to purify the water.

[0037] Example 4 S1 extracts sludge and adds lime for conditioning, then performs plate and frame filter press to obtain pretreated sludge. The pretreated sludge is mixed with sawdust additive at a mass ratio of 2.5:1 and granulated to obtain pellets. S2 smoldering the pellets on the ship to produce porous ceramic particles. The smoldering reaction conditions are: ignition temperature of 350℃, Darcy flow rate of air of 4.2cm / s, and average peak temperature of 1100℃. S3 introduces porous ceramic particles into the lake on-site to purify the water.

[0038] Example 5 S1 extracts sludge and adds lime for conditioning, then performs plate and frame filter press to obtain pretreated sludge. The pretreated sludge is mixed with sawdust and coal gasification slag additives at a mass ratio of 4:1 and then granulated to obtain pellets. S2 smoldering the pellets on the ship to produce porous ceramic particles. The smoldering reaction conditions are: ignition temperature of 400℃, Darcy flow rate of air of 5.6cm / s, and average peak temperature of 1100℃. S3 introduces porous ceramic particles into the lake on-site to purify the water.

[0039] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for integrated on-site treatment of lake silt, characterized in that, Specifically: S1 involves pumping out sludge, pre-treating it, and granulating it to obtain pellets, including the following sub-steps: S11 sucks up sludge and conditions and presses it to obtain pretreated sludge. Organic conditioner and / or inorganic conditioner are added to the sludge for conditioning. The organic conditioner includes polyacrylamide and the inorganic conditioner includes one or more of lime, fly ash, ferric chloride and aluminum sulfate. S12 The pretreated sludge is mixed with additives and shaped into pellets to obtain pellets. The additives are biomass powder and coal gasification slag. The mass ratio of the pretreated sludge to the additives is 7:3 to 4:

1. By adding biomass powder and coal gasification slag, the organic matter content of the pellets is increased, so that the peak temperature of smoldering combustion reaches more than 1000℃. Thus, while reducing volume and weight, the sintered porous ceramic particles have sufficient porosity and structural strength. S2 The material balls are smoldering in situ to produce porous ceramic particles. The material balls are fed into the smoldering reactor and preheated to 300°C to 400°C. Then the heating is stopped and air is introduced for ignition. S3 introduces the porous ceramic particles into the lake to purify the water.

2. The integrated on-site treatment method for lake silt as described in claim 1, characterized in that, In step S2, porous ceramic particles are prepared using either a continuous reaction or a batch reaction. When preparing porous ceramic particles using a continuous reaction, slag is discharged when the temperature of the bottom layer of the smoldering reactor is below 100°C. When preparing porous ceramic particles using a batch reaction, the reaction ends and slag is discharged when the center temperature begins to decrease or the oxygen concentration in the outlet flue gas is above 5.0 vol.%.

3. The integrated on-site treatment method for lake silt as described in claim 1, characterized in that, In step S2, the preheating time is 40 min to 60 min, and the Darcy flow rate of the introduced air is 3 cm / s to 6 cm / s.

4. A mobile platform for integrated on-site treatment of lake silt, characterized in that, The lake silt is disposed of in an integrated on-site manner using the integrated on-site disposal method for lake silt as described in any one of claims 1 to 3.

5. The mobile platform for integrated on-site treatment of lake silt as described in claim 4, characterized in that, The system includes a cutter suction dredger (1) and a sludge disposal vessel (2). The cutter suction dredger (1) is used to pump sludge and send it into the sludge disposal vessel (2). The sludge disposal vessel (2) is used to pre-treat and granulate the sludge to obtain pellets, and then smolder the pellets to produce porous ceramic particles and directly put them into the lake.

6. The mobile platform for integrated on-site treatment of lake silt as described in claim 5, characterized in that, The mobile platform also includes a shuttle boat (3) for transporting river sand generated by the sludge treatment vessel (2) for sale.

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