Channel dredging slurry treatment process and device based on water conservancy project

Abstract

The application discloses a waterway dredging slurry treatment process and device based on water conservancy projects, relates to the technical field of waterway dredging slurry treatment, and specifically comprises a drying cabin, wherein the drying cabin comprises a storage rack, a dehydration and solid discharge mechanism and a rotary distributing mechanism; the energy cycle innovation is adopted, the tail gas of a diesel engine is directly captured as a drying heat source, external energy supply is replaced, the energy consumption constraint of a mobile device is broken, the dehydration-drying integrated design is adopted, the centrifugal dehydration and thin-layer heat drying are combined, the water content is reduced to below 15%, the speed is increased by 50% compared with plate and frame filter pressing, the sleeve and the impact rod are linked to scrape the surface of the sleeve through the scraping plate, the adhesion and blockage problems are solved, and continuous treatment of high-viscosity slurry is ensured; that is, through the dual paths of process innovation and equipment integration, an efficient, low-consumption and mobile solution is provided for the treatment of dredging slurry, and the technical blank in the field of on-board real-time treatment is filled.

Description

Technical Field

[0001] This invention relates to the field of waterway dredging mud treatment technology, specifically to waterway dredging mud treatment process and apparatus based on water conservancy projects. Background Technology

[0002] The treatment of sludge (usually a mixture of water, silt, clay, organic matter and possible pollutants) generated from channel dredging is a key part of dredging projects, which is related to environmental compliance, resource utilization and cost control. The treatment process and equipment is a systematic project with the core objectives of reduction, harmlessness, stabilization and resource recovery.

[0003] The technical challenges of dredging mud treatment mainly lie in the high water content, complex composition, and the balance between treatment efficiency and environmental protection requirements. For example, the patent application CN118908521A involving CCCC Shanghai Waterway Bureau uses a three-stage mud tank connected in series with a plate and frame filter press to concentrate the mud through flocculation and sedimentation, and finally combines an air flotation unit and an artificial wetland to treat the wastewater.

[0004] Although this process can reduce the load on plate and frame filter presses, and has good treatment effect and fast dewatering, it has high energy consumption and a long natural dewatering cycle, making it difficult to meet the needs of continuous dredging operations. In addition, it requires a large site, needs to set up multiple mud pits and conditioning tanks, and has limited equipment integration and mobility, making it difficult to deploy large fixed treatment facilities on dredging vessels. This results in the need for onshore transfer of mud, increasing costs and pollution risks. Summary of the Invention

[0005] The purpose of this invention is to provide a process and device for treating dredging sludge based on water conservancy engineering. It adopts an energy recycling innovation, directly capturing diesel engine exhaust gas as a drying heat source to replace external energy supply and overcome the energy consumption constraints of mobile equipment. At the same time, the integrated dehydration-drying design combines centrifugal dehydration and thin-layer thermal drying to reduce the moisture content to below 15%, which is 50% faster than plate and frame filter press. It adopts a dual approach of process innovation and equipment integration to provide an efficient, low-consumption, and mobile solution for dredging sludge treatment, solving the problems mentioned in the background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a channel dredging mud treatment process based on water conservancy engineering, comprising the following steps:

[0007] Step 1: Preheat recovery. High-temperature exhaust gas from the diesel-powered dredging vessel engine is captured through a high-temperature resistant pipe, and sparks and large particulate impurities are removed by a cyclone dust collector before being discharged into a heat pipe heat exchanger.

[0008] Step 2: Using high-pressure steam as the heat transfer medium, the exhaust gas is first discharged into the heat pipe heat exchanger to transfer heat energy to the purified wastewater, and the generated high-temperature steam is discharged back into the drying chamber.

[0009] Step 3: The dredged mud is rapidly concentrated to a solids content of 20-30% by a hydrocyclone, and 0.1%-0.3% organic flocculant is added to improve the fluidity of the mud. At the same time, the screw pump transports the mud to the dewatering and solids removal mechanism.

[0010] Step 4: The sludge forms a uniform thin layer of 3-5mm in the drying chamber through the rotating material distribution mechanism. High-temperature steam circulates in the drying chamber casing to maintain the chamber temperature at 80-110℃. At the same time, the scraper at the bottom of the casing peels off and crushes the semi-dry sludge. The sludge falls down in stages on the multi-layer casing, with a total residence time of 10-30 minutes.

[0011] Step 5: The purified exhaust gas is sprayed into the drying chamber at a flow rate of 5-8 m / s, where it directly exchanges heat with the sludge. The exhaust gas from the drying chamber outlet enters the condenser tower, where it is first cooled to 30°C by a surface cooler, and then further cooled to 5°C by compression. The condensate is recycled and reused.

[0012] The present invention also proposes a channel dredging mud treatment device based on water conservancy engineering, which is applied to the channel dredging mud treatment process of the above-mentioned water conservancy engineering. It includes a drying chamber, which includes a storage rack, a dewatering and solidification mechanism and a rotating material distribution mechanism. The storage rack is installed on a diesel-powered dredging vessel, and the rotating material distribution mechanism is fixed to the top of the storage rack by bolts.

[0013] The top of the rotating fabric spreading mechanism is equipped with a dewatering and solidification mechanism, a filter box is installed on a storage rack on one side of the rotating fabric spreading mechanism, a slide is slidably connected to the bottom of the storage rack, and a storage cylinder is installed on the slide and located at the bottom of the rotating fabric spreading mechanism.

[0014] Furthermore, the dehydration and solids removal mechanism includes a centrifuge shell, an outer cover, and an inner cover. The outer cover is movably connected to one side of the centrifuge shell, and the inner cover is movably connected to the inside of the outer cover via a bearing. A sludge guide pipe is installed on the centrifuge shell, and one end of the sludge guide pipe passes through the inner cover and is movably connected to it. An exhaust port is provided at the top of the centrifuge shell, and the inner wall at the bottom of the centrifuge shell is connected to the filter box.

[0015] Furthermore, the inner cover has a roll blade fixed to its outer wall by welding on the opposite side of the outer cover. The inner cover and the outer cover rotate in opposite directions. The outer cover has filter holes evenly distributed on it.

[0016] Furthermore, the rotating fabric feeding mechanism includes a heat-conducting box, a sleeve, and a movable scraper. The inner walls on both sides of the heat-conducting box are evenly equipped with sleeves, and the sleeves are two wear-resistant ceramic hollow tubes arranged side by side with gears meshing at their ends. The sleeves arranged from top to bottom are spaced 2-3 cm apart, and movable scrapers are symmetrically installed at the bottom of the sleeves.

[0017] Furthermore, a scraper is slidably connected in the top channel of the movable scraper cover, a slide rod is slidably connected to one side of the movable scraper cover, a return spring sleeve is installed on the inner wall of one side of the movable scraper cover, one end of the slide rod passes through the movable scraper cover and abuts against the return spring sleeve, and a connecting rod is rotatably connected between the slide rod and the scraper.

[0018] Furthermore, dust removal sleeves are fixed to both sides of the heat conduction box by bolts, and an exhaust pipe is fixed to one side of the dust removal sleeve. A material release valve is installed at the bottom of the heat conduction box on the rotating material distribution mechanism.

[0019] Furthermore, a rotating sleeve is movably connected to the inner wall of the dust removal sleeve on one side and located on the movable scraper side via a bearing. A gear is installed on the rotating sleeve side and meshes with a transmission gear shaft. A gear is installed on one side of the transmission gear shaft and meshes with a gear at the end of the adjacent sleeve.

[0020] Furthermore, an impact rod is rotatably connected to the inner wall of the dust removal sleeve and the opposite surface of the rotating sleeve and the movable scraper cover. One side of the impact rod abuts against the rotating sleeve, and the other side abuts against the end of the sliding rod.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] In this invention, energy recycling and sludge dewatering efficiency are significantly improved. By capturing high-temperature exhaust gas from a diesel engine, the heat energy is converted into high-temperature steam through a heat pipe heat exchanger and directly used for sludge drying. At the same time, the purified exhaust gas is injected into the drying chamber at a high flow rate for secondary heat exchange, realizing the cascade utilization of exhaust gas energy. The exhaust gas is finally recycled by a condenser tower to recover condensate for reuse, forming a closed-loop system of "exhaust gas → steam → condensate". This reduces energy consumption by more than 60% compared to traditional electric heating or natural drying. In addition to sludge drying, the sludge is centrifuged at high speed in reverse through inner and outer covers, increasing the solid content from the initial 20-30% to more than 50% and improving the moisture filtration efficiency by 40%. Furthermore, the multi-layer sleeve with progressively thin layers of material, combined with dynamic heating by high-temperature steam, reduces the sludge moisture content from 70% to below 15%, improving the drying efficiency by more than 50%.

[0023] In this invention, a modular collaborative design and anti-clogging and anti-coking mechanism are adopted. The inner cover's rolling blades and the outer cover rotate in opposite directions to scrape off solid sludge, avoiding filter pore blockage. The transmission gear shaft drives the sleeve to squeeze and adhere the sludge, and the rotating sleeve's linkage impact rod triggers the scraper to scrape the material back and forth, realizing the full automation of the "centrifugal dewatering-thermal drying-scraping" process without additional energy consumption bottlenecks. At the same time, the device is modularly integrated into the dredging vessel's storage rack, and the slide storage cylinder design supports rapid unloading. The discharge valve can empty residual sludge with one click, reducing maintenance costs by 40% and facilitating effective sludge drying pretreatment during channel dredging. Attached Figure Description

[0024] Figure 1This is a schematic diagram of the process flow for treating dredging mud in water conservancy engineering according to the present invention.

[0025] Figure 2 This is a schematic diagram of the overall structure of the waterway dredging mud treatment device for water conservancy engineering according to the present invention.

[0026] Figure 3 This is a schematic diagram of the overall structure of the dehydration and solids removal mechanism of the present invention;

[0027] Figure 4 This is a schematic diagram of the heat-conducting box mounting sleeve structure inside the rotating fabric-making mechanism of the present invention;

[0028] Figure 5 This is a schematic diagram of the installation of the sleeve side-rotating sleeve and impact rod of the present invention;

[0029] Figure 6 This is a schematic diagram of the transmission gear shaft driving the upper and lower sleeves to rotate according to the present invention;

[0030] Figure 7 This is a schematic diagram of the connection structure between the scraper and the impact rod inside the active scraper cover of the present invention.

[0031] In the diagram: 1. Drying chamber; 10. Storage rack; 11. Dehydration and solids removal mechanism; 111. Centrifuge shell; 112. Sludge guide pipe; 113. Exhaust port; 114. Outer cover; 115. Inner cover;

[0032] 12. Rotating fabric feeding mechanism; 121. Heat conduction box; 122. Sleeve; 123. Movable scraper; 124. Transmission gear shaft; 125. Rotating sleeve; 126. Impact rod; 127. Slide rod; 128. Return spring sleeve; 129. Scraper; 2. Slide frame; 3. Material storage cylinder; 4. Filter box; 5. Discharge valve; 6. Dust removal sleeve. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1-7 The present invention provides a technical solution:

[0035] Example 1: This invention achieves efficient dewatering and drying of dredged mud on a diesel-powered dredging vessel through modular integration. The specific process is as follows: The dredged mud is first concentrated to a solids content of 20-30% by a hydrocyclone, and 0.2% organic flocculant is added to improve fluidity. It is then pumped by a screw pump to the dewatering and solids removal mechanism 11. Figure 3As shown, the sludge is discharged into the inner cover 115 through the sewage pipe 112. The inner cover 115 and the outer cover 114 rotate in opposite directions, with the inner cover 115 rotating counterclockwise and the outer cover 114 rotating clockwise. Under the action of centrifugal force, the sludge is thrown into the gap between the inner cover 115 and the outer cover 114.

[0036] Water is discharged through the filter holes on the outer cover 114 and flows into the filter box 4 for storage through the bottom of the centrifuge shell 111. The purified wastewater can be used for heat exchange in the early stage, while the dehydrated sludge is scraped off by the roll blades welded to the outer wall of the inner cover 115 and discharged into the rotating cloth mechanism 12.

[0037] Meanwhile, the high-temperature exhaust gas from the diesel engine is captured by a high-temperature resistant pipe, and after sparks and large particulate impurities are removed by a cyclone dust collector, it is introduced into a heat pipe heat exchanger. Heat energy is transferred through high-pressure steam, and the generated high-temperature steam is introduced into the sleeve 122 inside the rotating fabric distribution mechanism 12. Figure 2 and Figure 4 As shown, the sleeve 122 is installed inside the guide box 121, with the dust removal sleeve 6 on both sides. High-temperature water vapor flows into the sleeve 122 through the dust removal sleeve 6 for heat exchange.

[0038] The initially dewatered sludge is evenly distributed in the rotating cloth feeding mechanism 12, such as... Figure 4 As shown, the sludge enters through the inlet at the top of the heat transfer box 121, as... Figure 5 and Figure 6 As shown, the installed transmission gear shaft 124 drives the upper and lower sleeves 122 to rotate. When rotating clockwise, the upper and lower sleeves 122 simultaneously squeeze the falling sludge inward. The wet sludge adheres to the outer wall of the sleeve 122. Without the action of the scraper 129, some of the sludge falls directly, while the other part of the sludge adheres to the surface of the sleeve 122 and is dried by the high temperature sleeve 122, forming a thin layer of 3-5mm. To avoid the sludge from being over-dried and affecting subsequent drying operations, a movable scraper 123 is installed on the bottom side of the corresponding sleeve 122.

[0039] High-temperature steam circulates within the hollow casing 122, maintaining the chamber temperature. Sludge adheres to the surface of casing 122 for heat exchange. During this process, the scraper 129 at the bottom of the movable scraper 123... Figure 7 As shown, the semi-dry sludge is peeled off and crushed. The sludge falls step by step on the multi-layer sleeve 122 under gravity, with a total residence time of 20 minutes, and finally falls into the storage cylinder 3.

[0040] As for the drive of scraper 129, a rotating sleeve 125 is installed inside the dust removal sleeve on one side. It is also driven by the transmission gear shaft 124. The gear on one side of the rotating sleeve 125 meshes with the transmission gear shaft 124. The other side of the tube surface is cut with a notch and is abutted by the slide rod 127 inside the movable scraper cover 123 on one side. The impact rod 126 installed between the rotating sleeve 125 and the slide rod 127 presses against the outer wall of the rotating sleeve 125. As the rotating sleeve 125 rotates, the pushed impact rod 126 contacts the slide rod 127.

[0041] like Figure 7 As shown, when the slide bar 127 moves to the left, it also pushes the scraper 129 upward through the connecting rod, thereby contacting the sleeve 122 during the rotation process and scraping off the sludge adhering to its surface. The falling sludge will be squeezed and dried again, and finally the multi-stage drying and dewatering operation is completed. At the same time, the irregularity of the contact between the sludge and the sleeve 122 is improved. The entire movable scraper 123 will also deviate when the impact bar 126 contacts the slide bar 127, changing the position of the scraper 129 on the sleeve 122, forming a swinging scraping, which improves the sludge crushing and mixing effect and avoids uneven sludge drying.

[0042] Because the initial high-temperature exhaust gas has a high temperature after purification and heat transfer, it can be directly discharged into the drying chamber to raise the working temperature. The purified exhaust gas is sprayed into the drying chamber 1 at a flow rate of 6.5 m / s for direct heat exchange. As the sludge moisture in the heat transfer box evaporates, steam is continuously discharged from the exhaust port. The exhaust gas is then discharged into the condensation tower through a pipeline. After being cooled to 30°C by the surface cooler, it is compressed and refrigerated to 5°C. The condensate is also recycled. This deeply couples the exhaust gas waste heat recovery with sludge dewatering to achieve energy recycling. The sludge moisture content is reduced from the initial 70% to below 15%, meeting the standards for landfill or reuse. Compared with traditional natural drying, the efficiency is improved by more than 50%.

[0043] Example 2: Further refinement of the device operation regarding the collaborative mechanism between the dewatering and solid removal mechanism 11 and the rotating fabric distribution mechanism 12: For example... Figure 3 and Figure 4 As shown, in the dewatering and solids removal mechanism 11, the sewage guide pipe 112 passes through the inner cover 115 and is movably connected to it. The inner cover 115 is driven by an independent motor to rotate counterclockwise at a high speed of 900 rpm, and the outer cover 114 rotates in the opposite direction at a low speed of 250 rpm through a bearing.

[0044] After the sludge enters the inner cover 115, it impacts the inner wall of the outer cover 114 under centrifugal force. The water is discharged to the filter box 4 through the filter holes, while the solid sludge is pushed to the bottom outlet by the rolling blades of the inner cover 115 to avoid clogging. The discharged sludge falls into the top of the heat conduction box 121 of the rotating cloth mechanism 12.

[0045] The core of the drying stage lies in the dynamic heating and scraping of the sleeve 122: such as Figure 5-7As shown, the transmission gear shaft 124 is driven by a motor, which drives the upper and lower sleeves 125 to rotate synchronously. The sleeves 125 mesh with the gears at the end of the sleeve 122. When the sleeves 125 rotate, the sludge is squeezed and adhered to the surface of the sleeve 122.

[0046] At the same time, high-temperature steam flows through the inner cavity of the sleeve 125, continuously heating the sleeve 122 and quickly drying the sludge surface.

[0047] The scraping mechanism of the active scraper 123 is triggered by periodic impact: when the rotating sleeve 125 rotates, it pushes the impact rod 126, the impact rod 126 abuts against the slide rod 127, and after overcoming the resistance of the return spring sleeve 128, it pushes the connecting rod, which drives the scraper 129 to slide back and forth on the surface of the sleeve 122, peeling off and crushing the semi-dry sludge. The peeled sludge falls to the next layer of sleeve 122, repeating the drying process. The multi-layer design ensures uniform dewatering. If large pieces of sludge are encountered, the gear transmission system of the rotating sleeve 125 will be activated.

[0048] like Figure 6 As shown, by adjusting the pressure through differential speed, overheating and coking are avoided. That is, continuous operation of "centrifugal dehydration-thermal drying-scraping" is achieved through mechanical linkage, without any additional energy consumption bottleneck. The dried sludge can be discharged through the discharge valve 5. For this purpose, a slide is installed on the storage rack 10 at the bottom of the entire drying chamber 1. A storage cylinder 3 is installed on the slide 2. After the discharge valve 5 is opened, the dried sludge falls into the storage cylinder 3, which is convenient for subsequent personnel to transfer the sludge.

[0049] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A waterway dredging mud treatment device based on water conservancy engineering, characterized in that, The container includes a drying chamber (1), which includes a storage rack (10), a dehydration and solidification mechanism (11), and a rotating fabric spreading mechanism (12). The storage rack (10) is installed on a diesel-powered dredging vessel, and the rotating fabric spreading mechanism (12) is fixed to the top of the storage rack (10) by bolts. The top of the rotating fabric mechanism (12) is equipped with a dewatering and solidification mechanism (11), and a filter box (4) is installed on the storage rack (10) on one side of the rotating fabric mechanism (12). A slide (2) is slidably connected to the bottom of the storage rack (10), and a storage cylinder (3) is installed on the slide (2) and located at the bottom of the rotating fabric mechanism (12). The rotating fabric feeding mechanism (12) includes a heat-conducting box (121), a sleeve (122), and a movable scraper (123). The sleeves (122) are evenly installed on the inner walls of both sides of the heat-conducting box (121). The sleeves (122) are two wear-resistant ceramic hollow tubes arranged side by side, with gears meshing at the ends. The spacing between the sleeves (122) arranged from top to bottom is 2-3 cm. Movable scrapers (123) are also symmetrically installed at the bottom of the sleeves (122). A scraper (129) is slidably connected in the top channel of the movable scraper cover (123). A slide rod (127) is slidably connected to one side of the movable scraper cover (123). A return spring sleeve (128) is installed on the inner wall of one side of the movable scraper cover (123). One end of the slide rod (127) passes through the movable scraper cover (123) and abuts against the return spring sleeve (128). A connecting rod is rotatably connected between the slide rod (127) and the scraper (129). Dust removal sleeves (6) are fixed to both sides of the heat conduction box (121) by bolts. One side of the dust removal sleeve (6) is connected to and fixed with an exhaust pipe. A material release valve (5) is installed at the bottom of the heat conduction box (121) on the rotating fabric distribution mechanism (12). A rotating sleeve (125) is movably connected to the inner wall of the dust removal sleeve (6) on one side and located on the side of the movable scraper (123) via a bearing. The side wall of the rotating sleeve (125) is cut with a notch. A gear is installed on the side of the rotating sleeve (125) and meshes with a transmission gear shaft (124). A gear is installed on one side of the transmission gear shaft (124) and meshes with the gear at the end of the adjacent side sleeve (122). The dust removal sleeve (6) has an impact rod (126) rotatably connected to the inner wall of the sleeve (125) and the opposite side of the movable scraper (123). One side of the impact rod (126) abuts against the sleeve (125), and the other side abuts against the end of the slide rod (127).

2. The waterway dredging mud treatment device based on water conservancy engineering according to claim 1, characterized in that, The dehydration and solid removal mechanism (11) includes a centrifuge shell (111), an outer cover (114) and an inner cover (115). The outer cover (114) is movably connected to one side of the centrifuge shell (111), and the inner cover (115) is movably connected to the inner side of the outer cover (114) through a bearing. A sludge guide pipe (112) is installed on the centrifuge shell (111), and one end of the sludge guide pipe (112) passes through the inner cover (115) and is movably connected to it. An exhaust port (113) is opened at the top of the centrifuge shell (111), and the inner wall of the bottom of the centrifuge shell (111) is connected to the filter box (4).

3. The waterway dredging mud treatment device based on water conservancy engineering according to claim 2, characterized in that, The inner cover (115) has a roll blade fixed to its outer wall and opposite to the outer cover (114) by welding. The inner cover (115) and the outer cover (114) rotate in opposite directions. The outer cover (114) has filter holes evenly distributed on it.

4. A waterway dredging mud treatment process based on water conservancy engineering, characterized in that, The method described in claim 3, which is a waterway dredging mud treatment device based on water conservancy engineering, includes the following steps: Step 1: Preheat recovery. High-temperature exhaust gas from the diesel-powered dredging vessel engine is captured through a high-temperature resistant pipe, and sparks and large particulate impurities are removed by a cyclone dust collector before being discharged into a heat pipe heat exchanger. Step 2: First, exhaust gas is discharged into a heat pipe heat exchanger to transfer heat energy to the purified wastewater, and the generated high-temperature steam is discharged into the drying chamber (1). Step 3: The dredged mud is rapidly concentrated to a solids content of 20-30% by a hydrocyclone, and 0.1%-0.3% organic flocculant is added to improve the fluidity of the mud. At the same time, the screw pump delivers the mud to the dewatering and solids removal mechanism (11). Step 4: The dewatered sludge forms a uniform thin layer of 3-5 mm in the drying chamber (1) through the rotating cloth feeding mechanism (12). High-temperature steam circulates in the casing (122) of the drying chamber (1) to maintain the chamber temperature at 80-110℃. At the same time, the scraper (129) at the bottom of the casing (122) peels off and crushes the semi-dry sludge. The sludge falls down step by step on the multi-layer casing (122), with a total residence time of 10-30 minutes. Step 5: The purified exhaust gas after heat transfer is sprayed into the drying chamber (1) at a flow rate of 5-8 m / s to exchange heat directly with the sludge. The exhaust gas at the outlet of the drying chamber (1) enters the condenser tower, is first cooled to 30°C by the surface cooler, and then cooled to 5°C by compression. The condensate is recycled and reused.

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