Integrated on-site treatment method for lake sludge and mobile platform

Abstract

The invention belongs to the field of sludge treatment, and particularly discloses a lake sludge integrated on-site treatment method and a mobile platform, the method comprises the following steps: sucking sludge, pre-treating, forming and granulating to obtain material balls, and then carrying out on-site smoldering combustion on the material balls to prepare porous ceramic particles; and finally, the porous ceramic particles are put into the lake to play a role in purifying water. The smoldering technology is introduced into lake sludge treatment, the advantage that smoldering can achieve self-maintaining continuous reaction is utilized, sludge does not need to be transported to the land for treatment, material balls can be subjected to dehydration and decarburization treatment only by means of a small amount of heat input, and the sludge treatment efficiency is improved. And the generated porous ceramic particles can play a role in purifying water after being directly put into the lake, so that the integrated in-situ deep treatment of the lake sludge is realized.

Description

Technical Field

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

[0002] Lake siltation refers to the accumulation of a large amount of mud and sand in the lake. When rainwater and frozen water melt and flow into the lake, the cross-section expands and the flow rate slows down, which slows down the movement of mud and sand, resulting in siltation. Lake siltation has increasingly affected the normal functioning of lakes such as flood control, drainage, irrigation, water supply, and navigation. In order to restore the normal functions of lakes and promote the rapid and sustainable development of the economy and society, it is very necessary to carry out lake dredging projects.

[0003] Traditional lake dredging requires the bottom mud to be transported to land for dehydration and harmless treatment, which occupies a lot of land resources, takes a long time, and also affects the surrounding ecological environment. In addition, there have been some attempts at new ways to dredge lakes. For example, the "Taihu Star" is the first in China to "move" the environmentally friendly flocculant delivery 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 and flocculant adjustment, dehydration and volume reduction, and harmless treatment on water. This method solves the problem of sludge solidification occupying land resources to a certain extent, but it is still difficult to achieve on-site deep disposal and reuse of sludge. Summary of the invention

[0004] In response to the defects of the prior art, the present application provides an integrated on-site disposal method and mobile platform for lake sludge, aiming to solve the problem that the existing lake dredging methods occupy land resources and cannot achieve on-site deep disposal of sludge.

[0005] According to one aspect of the present application, a method for integrated on-site disposal of lake sludge is provided, specifically: S1 sucks the sludge and performs pretreatment and granulation to obtain pellets; S2 smoldering the pellets in situ to produce porous ceramic particles; S3: throwing the porous ceramic particles into the lake to purify the water.

[0006] Compared with the prior art, the above technical scheme conceived by the present application can realize the integrated on-site disposal of lake sludge by introducing the smoldering combustion technology into the disposal of lake sludge. There is no need to transport the lake sludge to land for treatment to avoid occupying land resources, and the generated porous ceramic particles are directly put into the lake to purify the water quality.

[0007] As further preferred, step S1 includes the following sub-steps: S11 sucks the sludge and performs conditioning and filter pressing to obtain pretreated sludge; S12: mixing the pretreated sludge with additives and forming and granulating the mixture to obtain pellets.

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

[0009] As further preferred, 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 further preferred, in step S2, the specific process of smoldering combustion is: feeding the pellets into a smoldering reactor and preheating them to 300° C. to 400° C., then stopping the heating and introducing air for ignition.

[0011] As a further preferred embodiment, in step S2, porous ceramic particles are prepared by continuous reaction or batch reaction, wherein, when porous ceramic particles are prepared by continuous reaction, slag is discharged when the temperature of the bottom layer of the smoldering reactor is lower than 100°C; when porous ceramic particles are prepared by batch reaction, the reaction is terminated and slag is discharged when the center temperature begins to decrease or the oxygen concentration in the outlet flue gas is higher than 5.0 vol.%.

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

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

[0014] As a further preference, the mobile platform comprises a dredging suction boat and a sludge disposal boat, the dredging suction boat is used to suck the sludge and send it to the sludge disposal boat; the sludge disposal boat is used to pre-treat and shape the sludge into granules to obtain pellets, and then smolder the pellets to obtain porous ceramic particles and directly throw them into the lake.

[0015] As a further preference, the mobile platform also includes a shuttle boat, which is used to shuttle and transport the river sand produced by the sludge disposal ship for sale.

[0016] In general, the above technical solutions conceived by this application have the following technical advantages compared with the prior art: 1. This application aims to solve the problem that existing lake dredging methods occupy land resources and cannot achieve deep on-site disposal of sludge. This application proposes an integrated on-site disposal method for lake sludge. This method introduces smoldering technology into lake sludge disposal. By taking advantage of the self-sustaining continuous reaction of smoldering, there is no need to transport the sludge to land for treatment. Only a small amount of heat input is required to dehydrate and decarbonize the pellets. The generated porous ceramic particles can be directly put into the lake to purify the water quality, thereby achieving integrated on-site deep disposal 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 sludge, and can achieve the role of synergistic preparation of ceramsite from multiple wastes. On the one hand, by adding biomass powder and / or coal gasification slag to increase the organic matter content of the pellets, the peak temperature of the smoldering combustion reaches above 1000°C, thereby achieving volume reduction and amount reduction while making 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. At the same time, the mobile platform for integrated on-site disposal of lake sludge provided by this application realizes the integrated disposal of river sludge and effective reduction of floor space by relying on smoldering technology. The sludge disposal ship 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 floor space and a more integrated disposal process route, avoiding the space limitation caused by the excessive occupation of traditional equipment, and is particularly suitable for confined space environments such as lake surface disposal platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the process of the integrated on-site disposal method of lake sludge provided in the embodiment of the present application; Figure 2 It is a three-dimensional schematic diagram of the mobile platform for integrated on-site disposal of lake sludge provided in an embodiment of the present application.

[0018] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1- suction boat, 2- sludge disposal boat, 21- pretreatment assembly, 22- filter press assembly, 23- pelletizing assembly, 24- smoldering reactor, 3- shuttle boat. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0020] like Figure 1 As shown, the present application provides an integrated on-site disposal method for lake sludge, specifically: S1 sucks the sludge and performs pretreatment and granulation to obtain pellets; S2 smolders the pellets in situ to produce porous ceramic particles; S3 dumps porous ceramic particles into the lake to purify the water.

[0021] This application takes into account that the onshore sintering system is complex, occupies a large area, and has high energy consumption, and is not suitable for the confined space of ships. Therefore, the smoldering combustion technology is introduced into the lake sludge disposal. The smoldering combustion technology does not require additional dehydration, has a high volume reduction rate, and is completely harmless to achieve self-sustaining continuous reaction. It does not need to transport the sludge to land for treatment and does not need to invest too much heat. The lake sludge can be disposed of in situ, thereby avoiding the occupation of land resources. The generated porous ceramic particles are directly put into the lake, which can purify the water quality. The existing lake sludge treatment process has high energy consumption, incomplete volume reduction, and still needs to be transported back to the shore for secondary disposal. It can achieve deep volume reduction of lake sludge, can collaboratively prepare porous ceramic particles, and return the lake to purify the water quality on the spot. There is no need to reserve a large amount of sludge or mud cake storage space on the ship. The deep volume reduction and absorption of sludge can be achieved on the spot, and there is no need to hand it over to the downstream for secondary disposal after landing, which greatly reduces the cost and disposal process.

[0022] Further, step S1 includes the following sub-steps: S11 sucks the sludge and conditions it, and then performs plate and frame filter pressing to reduce the moisture content of the sludge to about 50%, thereby obtaining pre-treated sludge; S12 mixes the pretreated sludge with additives and performs molding and granulation to obtain pellets.

[0023] Further, in step S11, an organic conditioning agent and / or an inorganic conditioning agent is added to the sludge for conditioning, thereby quickly flocculating fine particles in the sludge and improving dehydration energy absorption. The organic conditioning agent includes polyacrylamide, and the inorganic conditioning agent 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, so as to obtain a material ball with a particle size between 10 mm and 40 mm. If the proportion of additives is small, the low calorific value of the raw material will lead to too low smoldering peak temperature, thereby affecting the strength of ceramsite; if the proportion of additives is too large, the calorific value of the raw material is too high, which may lead to excessive sintering, thereby affecting the pore structure of ceramsite, so the mass ratio of pretreated sludge to additive in the smoldering reaction is preferably 7:3 to 4:1. Among them, the biomass powder preferably uses biomass with a calorific value of 2000kcal / kg to 4000kcal / kg, such as sawdust, rice husks, etc.

[0025] In the prior art, the smoldering temperature of sludge is roughly around 400℃~600℃, and the main method is to reduce the amount of sludge. The ash and slag also need to be transported for terminal disposal. This application can increase the organic matter content of the pellets by mixing additives including biomass powder and coal gasification slag, and optimize the mixing ratio of the additives, so that the peak temperature of the smoldering combustion reaches 1000℃~1100℃, and the sintered porous ceramic particles have sufficient pores and structural strength while achieving volume reduction and reduction, especially mixing raw materials with a high fixed carbon / volatile matter ratio, which is conducive to achieving the target sintering temperature and achieving continuous and stable operation. In addition, the calcium element in the biomass powder and coal gasification slag has a fluxing effect, which is conducive to reducing the sintering temperature and improving the sintering performance of the ceramsite. The silicon and aluminum elements in the biomass powder and coal gasification slag can react with the metal components in the sludge at high temperature 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: the pellets are sent into a smoldering reactor and preheated to 300°C to 400°C, the preheating time is preferably 40min to 60min, then the heating is stopped and air is introduced for ignition, the Darcy flow rate of the introduced air is preferably 3cm / s to 6cm / s, so that the pellets are smoldering to obtain porous ceramic particles. The pellets undergo drying, pyrolysis, oxidation, and gasification in sequence to finally form porous ceramic particles, and the peak temperature of this process can reach 1000°C to 1200°C.

[0027] When porous ceramic particles are prepared by continuous reaction, slag is discharged when the temperature of the bottom layer of the smoldering reactor is lower than 100°C, and new balls are directly fed in without preheating and ignition; when porous ceramic particles are prepared by batch reaction, the reaction is terminated and slag is discharged when the center temperature begins to decrease or the oxygen concentration in the outlet flue gas is higher than 5.0 vol.%, and then new balls are fed in and re-preheated and ignited.

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

[0029] In a preferred embodiment of the present application, the mobile platform includes a dredging vessel 1 and a sludge disposal vessel 2. The dredging vessel 1 continuously excavates and sucks the sludge from the lake bottom through an underwater spiral auger, and continuously transports the sludge to the sludge disposal vessel 2 through a sludge pipeline. The sludge treatment vessel 2 is used to condition the sludge and then perform plate and frame filter pressing to obtain pretreated sludge with a moisture content reduced to about 50%. The pretreated sludge is mixed with additives and formed into granules to obtain pellets. The pellets are sent to the smoldering reactor for dehydration and decarbonization to obtain porous ceramic particles and directly thrown into the lake to further purify the water quality.

[0030] Preferably, the sludge disposal ship 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, remove large solid particles such as sand and gravel, and add a conditioning agent before sending it to the filter press component 22 for filter pressing to obtain pretreated sludge; the pretreated sludge is mixed with the additive and then formed and granulated in the pelletizing component 23 to obtain material balls; the material balls are dehydrated and decarbonized in the smoldering reactor 24 to obtain porous ceramic particles. The smoldering reactor 24 preferably adopts a vertical structure, which can effectively save floor space and realize the 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 shuttle and transport the river sand produced by the sludge disposal ship for sale.

[0032] It should be noted that the application scenarios of the integrated on-site disposal method and mobile platform for lake sludge provided in this application are not limited to lakes, but can also be used in rivers, rivers and other water environments with large amounts of silt.

[0033] The technical solution provided in this application is further described below based on specific embodiments.

[0034] Example 1 S1 sucks the sludge and adds polyacrylamide for conditioning, then performs plate and frame filter pressing to obtain pre-treated sludge, mixes the pre-treated sludge with the coal gasification slag additive in a mass ratio of 7:3, and performs molding and granulation to obtain pellets S2 smolders the pellets on board to obtain porous ceramic particles. The reaction conditions for the smoldering combustion are an ignition temperature of 300°C, a Darcy velocity of air of 4 cm / s, and an average peak temperature of 1100°C during the smoldering reaction. S3 dumps porous ceramic particles into the lake to purify the water.

[0035] Example 2 S1 sucks the sludge and adds lime for conditioning, then performs plate and frame filter pressing to obtain pre-treated sludge, mixes the pre-treated sludge with sawdust additive at a mass ratio of 3.5:1 and forms pellets to obtain pellets S2 smolders the pellets on board to obtain porous ceramic particles. The reaction conditions for the smoldering combustion are an ignition temperature of 350°C, a Darcy velocity of air of 4.2 cm / s, and an average peak temperature of 1000°C during the smoldering reaction. S3 dumps porous ceramic particles into the lake to purify the water.

[0036] Example 3 S1 sucks the sludge and adds polyacrylamide for conditioning, then performs plate and frame filter pressing to obtain pre-treated sludge, mixes the pre-treated sludge with the coal gasification slag additive in a mass ratio of 4:1, and performs molding and granulation to obtain pellets S2 smolders the pellets on board to obtain porous ceramic particles. The reaction conditions for the smoldering combustion are an ignition temperature of 300°C, a Darcy velocity of air of 4 cm / s, and an average peak temperature of 1050°C during the smoldering process. S3 dumps porous ceramic particles into the lake to purify the water.

[0037] Example 4 S1 sucks the sludge and adds lime for conditioning, then performs plate and frame filter pressing to obtain pre-treated sludge, mixes the pre-treated sludge with sawdust additive at a mass ratio of 2.5:1 and forms pellets to obtain pellets S2 smolders the pellets on board to obtain porous ceramic particles. The reaction conditions for the smoldering combustion are an ignition temperature of 350°C, a Darcy velocity of air of 4.2 cm / s, and an average peak temperature of 1100°C during the smoldering reaction. S3 dumps porous ceramic particles into the lake to purify the water.

[0038] Example 5 S1 sucks the sludge and adds lime for conditioning, then performs plate and frame filter pressing to obtain pre-treated sludge, mixes the pre-treated sludge with sawdust and coal gasification slag additives in a mass ratio of 4:1, and forms and granulates the pre-treated sludge to obtain pellets. S2 smolders the pellets on board to obtain porous ceramic particles. The reaction conditions for the smoldering combustion are an ignition temperature of 400°C, a Darcy velocity of air of 5.6 cm / s, and an average peak temperature of 1100°C during the smoldering reaction. S3 dumps porous ceramic particles into the lake to purify the water.

[0039] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An integrated on-site disposal method for lake sludge, characterized in that: Specifically: S1 sucks the sludge and performs pretreatment and granulation to obtain pellets; S2 smoldering the pellets in situ to produce porous ceramic particles; S3: throwing the porous ceramic particles into the lake to purify the water.

2. The integrated on-site disposal method according to claim 1, characterized in that: Step S1 includes the following sub-steps: S11 sucks the sludge and performs conditioning and filter pressing to obtain pretreated sludge; S12: mixing the pretreated sludge with additives and forming and granulating the mixture to obtain pellets.

3. The integrated on-site disposal method according to claim 2, characterized in that: In step S11, an organic conditioning agent and / or an inorganic conditioning agent is added to the sludge for conditioning, wherein the organic conditioning agent includes polyacrylamide, and the inorganic conditioning agent includes one or more of lime, fly ash, ferric chloride and aluminum sulfate.

4. The integrated on-site disposal method according to claim 2, characterized in that: 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.

5. The integrated on-site disposal method according to claim 1, characterized in that: In step S2, the specific process of smoldering combustion is: the pellets are sent into a smoldering reactor and preheated to 300°C to 400°C, and then the heating is stopped and air is introduced for ignition.

6. The integrated on-site disposal method according to claim 5, characterized in that: In step S2, porous ceramic particles are prepared by continuous reaction or batch reaction. When the porous ceramic particles are prepared by continuous reaction, slag is discharged when the temperature of the bottom layer of the smoldering reactor is lower than 100°C; when the porous ceramic particles are prepared by batch reaction, the reaction is terminated and slag is discharged when the center temperature begins to decrease or the oxygen concentration in the outlet flue gas is higher than 5.0 vol.%.

7. The integrated on-site disposal method according to claim 5, 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.

8. A mobile platform for implementing the integrated on-site disposal method as described in any one of claims 1 to 7.

9. The mobile platform according to claim 8, characterized in that: The invention comprises a suction dredging vessel (1) and a sludge disposal vessel (2), wherein the suction dredging vessel (1) is used to suck the sludge and deliver it to the sludge disposal vessel (2); the sludge disposal vessel (2) is used to pre-treat the sludge and form and granulate it to obtain pellets, and then smolder the pellets to obtain porous ceramic pellets and directly throw them into a lake.

10. The mobile platform according to claim 9, characterized in that: The mobile platform also includes a barge (3), and the barge (3) is used to barge and transport the river sand produced by the sludge disposal ship (2) for sale.

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