Device and method for increasing concentration of slurry in pipeline

Abstract

The invention relates to a device and method for increasing the concentration of slurry in a pipeline, the device comprises an outer pipeline, an inner pipeline, a flange connecting assembly and a monitoring system, a plurality of overflow holes are uniformly distributed in the pipe wall of the outer pipeline, and the overflow holes are communicated with a residual water treatment device through a diversion pipeline; the inner pipeline is coaxially nested in the outer pipeline; the flange connecting assemblies are symmetrically arranged at the two ends of the device and used for achieving sealed connection of the inner pipeline and the slurry conveying pipeline. The monitoring system is integrated on a slurry conveying pipeline at the inlet end and the outlet end of the device, comprises an electromagnetic flowmeter and a pressure transmitter, and is used for collecting slurry flow velocity and pipeline pressure data in real time; the invention has the advantages that: through a double-layer pipeline structure (an outer pipeline and a filter cloth inner pipeline) and dynamic pressure regulation and control, synchronous dehydration in the conveying process is realized, meanwhile, the concentration in the slurry conveying process is synchronously increased, the problems of large occupied area and low efficiency of the traditional concentration tank are solved, and the concentration tank has remarkable economic and environment-friendly benefits.

Description

Technical Field

[0001] The present invention belongs to the field of mud pretreatment and mud reduction, and in particular to a device and method for increasing mud concentration in a pipeline. Background Art

[0002] Sediment pollution in rivers and lakes is a significant environmental issue. Its intensification is primarily due to human factors, as large quantities of persistent pollutants accumulate in the sediments of rivers and lakes. These pollutants are gradually released over time, causing significant negative impacts on river and lake water bodies. Therefore, the remediation of contaminated sediments is urgent.

[0003] The current slurry reduction process involves removing impurities from the slurry before it enters a thickening tank for gravity concentration. Slurry supply equipment then feeds the concentrated slurry into a homogenizing tank, where a curing agent is added. After the slurry and curing agent are fully mixed in the homogenizing tank, the slurry is pumped into a dewatering system for extrusion and dehydration. After a certain period of dehydration, a mud cake and tail water are formed, achieving the desired effect of mud-water separation and slurry reduction.

[0004] In the sludge reduction process, sludge concentration is not only crucial to the overall dehydration effectiveness and efficiency of the entire process, but also a significant factor influencing project costs. Therefore, sludge concentration has always been a key focus for engineering project teams. To increase sludge concentration, current practices typically involve excavating thickening tanks, where gravity settles the sludge particles. The surface clear liquid is then discharged through a decanter, thereby increasing the sludge concentration. However, thickening tanks often occupy large areas and are typically around 5 meters deep, sometimes as deep as 8 meters. These cofferdams are prone to collapse or leakage in harsh environments such as heavy rain, creating safety risks.

[0005] For example, a lakebed mud desilting and sludge dewatering and drying project in Wuhan covers an area of ​​approximately 50 mu (approximately 1.5 acres), while the concentration tanks cover approximately 24 mu (approximately 48%) of the total construction site. In the Xiamen Haicang Inner Lake mud dewatering and drying project, the concentration tanks account for approximately 43% of the total dewatering system area. Mud reduction technology, due to its requirement for larger concentration tanks, severely limits its application scenarios, particularly in urban river and lake mud dewatering, where space is limited. Furthermore, river and lake mud has complex properties, and the natural settling rates of different muds vary significantly, resulting in varying settling times. This often prevents smooth integration with subsequent dewatering systems, impacting construction efficiency. Finally, because river and lake mud often has a high organic matter content, prolonged exposure to the concentration tanks causes microorganisms in the mud to multiply, producing foul odors and polluting the environment. In severe cases, this can lead to work stoppages or even disruptions.

[0006] In summary, through field investigation and analysis, the following problems exist in the existing technology: the mud is directly transported in the pipeline without conditioning, and the water content of the mud in the pipeline is relatively high, which requires a large amount of space to store the mud before drying. In particular, the organic matter content in the mud at the bottom of rivers and lakes is often high. The mud is exposed in the concentration tank for a long time, which will emit a foul odor and easily cause secondary environmental pollution to the surrounding air. At the same time, the high water content in the mud is not conducive to the subsequent treatment of the mud, and the cost of subsequent treatment of the mud will also be high. Summary of the Invention

[0007] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and to provide a device and method for increasing the concentration of mud in a pipeline.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A device for increasing the mud concentration in a pipeline comprises: an outer pipeline having a plurality of overflow holes evenly distributed on its wall, the overflow holes being connected to a residual water treatment device via a diversion pipeline; an inner pipeline coaxially nested inside the outer pipeline, made of a filter cloth material having water permeability and elastic deformation capability, and having an inner diameter smaller than the nominal inner diameter of the mud conveying pipeline; a flange connection assembly symmetrically arranged at both ends of the device for achieving a sealed connection between the inner pipeline and the mud conveying pipeline; a monitoring system integrated into the mud conveying pipeline at the inlet and outlet ends of the device, comprising an electromagnetic flowmeter and a pressure transmitter for real-time acquisition of mud flow rate and pipeline pressure data.

[0010] Preferably, the filter cloth material of the inner pipe is selected from polyester or polypropylene polyester fiber braid, and the pore size of the filter cloth is smaller than the minimum particle size of the mud particles.

[0011] Preferably, the outer pipe is a rigid pipe body, the inner diameter of which is 5-20 cm larger than the outer diameter of the inner pipe. The pipe body is made of PVC, HDPE or seamless steel pipe, and its length is equal to that of the inner pipe and completely covers the inner pipe.

[0012] Preferably, the device is a standardized modular unit, with a single module length of 2-3 m, and is detachably connected in series with a straight pipe section of a mud conveying pipeline via a flange connection assembly.

[0013] Another object of the present invention is to provide a method for increasing the concentration of mud in a pipeline.

[0014] In order to achieve the above second purpose, the technical solution adopted by the present invention is:

[0015] A method for increasing the concentration of mud in a pipeline, the method comprising the following steps:

[0016] (a) In a straight section of a slurry conveying pipeline, a target pipe section is cut off and replaced with the device;

[0017] (b) When the mud flows through the inner pipe, the flow velocity increases due to the contraction of the pipe diameter, and the lateral pressure of the mud on the pipe wall increases to 0.2-0.8 MPa, forcing the interstitial water to penetrate the filter cloth and enter the outer pipe cavity;

[0018] (c) Directly guide interstitial water to the residual water treatment device through the overflow hole of the external pipeline. At the same time, the monitoring system is used to dynamically adjust the power of the delivery pump to maintain the pipeline pressure fluctuation amplitude and prevent delivery interruption due to head loss;

[0019] (d) The dehydrated mud particles form a concentration gradient in the inner pipe, and the final output concentration is 1.5-3 times higher than the inlet concentration.

[0020] Preferably, in step (b), the lateral pressure is regulated by:

[0021] The pore size of the filter cloth is selected according to the mud particle size distribution; the filtration flux is adaptively adjusted through the elastic deformation of the inner pipe, and the deformation range is controlled within 5%-15% of the pipe diameter to ensure a balance between mud particle retention and interstitial water extrusion.

[0022] Preferably, in step (c), the residual water treatment device comprises a sedimentation tank and a flocculant dosing unit.

[0023] Due to the adoption of the above technical solution, the beneficial effects obtained by the present invention include:

[0024] 1. The present invention uses a double-layer pipeline structure (external pipeline + filter cloth inner pipeline) and dynamic pressure control to achieve synchronous dehydration during transportation, while also increasing the concentration of mud during transportation. This solves the problems of large footprint and low efficiency of traditional thickening tanks, and has significant economic and environmental benefits.

[0025] 2. In the present invention, the inner pipe adopts elastic permeable filter cloth, which generates lateral pressure to squeeze the interstitial water by shrinking the pipe diameter, and the outer pipe collects overflow water and prevents splashing pollution; its monitoring system can adjust the flow rate and pressure in real time to ensure continuous and stable operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of an embodiment of the device for increasing the mud concentration in a pipeline according to the present invention.

[0027] Figure 2 It is a cross-sectional view of part A of an embodiment of the device for increasing the mud concentration in a pipeline according to the present invention.

[0028] Figure 3 It is a cross-sectional view of part B of an embodiment of the device for increasing the mud concentration in a pipeline according to the present invention.

[0029] Figure 4It is a schematic diagram of an embodiment of the device for increasing the mud concentration in a pipeline according to the present invention.

[0030] Figure 5 It is a partial implementation diagram of an embodiment of the device for increasing the mud concentration in a pipeline described in the present invention.

[0031] The reference numerals are as follows:

[0032] 1. External pipeline; 2. Internal pipeline; 3. Flange connection components; 4. Monitoring system;

[0033] 5. Overflow hole; 6. Mud conveying pipeline; 8. Residual water treatment device. DETAILED DESCRIPTION

[0034] Example 1

[0035] See Figure 1-5 As shown, the present invention mainly provides a device for increasing the concentration of mud in a pipeline, which aims to achieve synchronous dehydration of mud during pipeline transportation without relying on a concentration tank, and solve the problems of blockage, unstable efficiency and overflow water pollution of existing pipeline filtering devices. Based on this, the device includes an outer pipeline 1, an inner pipeline 2, a flange connection component 3 and a monitoring system 4; in this embodiment, the outer pipeline 1 is a rigid pipe body, whose inner diameter is 5-20 cm larger than the outer diameter of the inner pipeline 2. The pipe body is made of PVC, HDPE or seamless steel pipe, and its length is the same as that of the inner pipeline and completely covers the inner pipeline 2. A number of overflow holes 5 are evenly distributed on the pipe wall. The overflow holes 5 are connected to the residual water treatment device 8 through a diversion pipeline, and the overflow holes 5 are convenient for collecting interstitial water squeezed out of the mud.

[0036] In this embodiment, the inner pipe 2 is coaxially nested within the outer pipe 1 and is made of a filter cloth material having water permeability and elastic deformation ability, and its inner diameter is smaller than the nominal inner diameter of the mud conveying pipe 6. As a preferred embodiment, the filter cloth material of the inner pipe 2 is selected from a polyester or polypropylene polyester fiber braid, and its pore size distribution can range from 10 to 200 μm, with an elongation at break ≥15%, and a water permeability coefficient ≥0.1 cm / s. The filter cloth pore size is smaller than the minimum particle size of the mud particles, thereby effectively filtering out water and retaining the mud particles in the pipe.

[0037] In this embodiment, the flange connection assembly 3 is symmetrically arranged at both ends of the device, and is used to achieve a sealed connection between the inner pipe 2 and the mud conveying pipe 6; wherein, the flange connection assembly 3 can adopt the ANSI 150 grade flange standard to ensure the rapid sealed docking of the device and the conveying pipe; and the flange connection assembly 3 generally refers to a detachable joint in which two pipes, pipe fittings or equipment are first fixed on a flange plate respectively, and then a flange gasket is added between the two flange plates, and finally the two flange plates are tightened with bolts to make them tightly combined. It can realize the connection between a stationary pipe and a rotating or reciprocating device. Its structure is an existing mature technology, and its structural principle is not elaborated here.

[0038] In this embodiment, the monitoring system 4 is integrated into the mud conveying pipeline at the inlet and outlet ends of the device, and includes an electromagnetic flowmeter and a pressure transmitter for real-time collection of mud flow rate and pipeline pressure data. During the mud conveying process, the monitoring device 4 can collect data in real time, adjust the conveying pump power, and maintain pressure fluctuations, thereby effectively monitoring the mud conveying in the pipeline, avoiding the pressure drop in the pipeline caused by changes in mud concentration and head loss caused by the device, and affecting the mud conveying to the designated location; among them, the electromagnetic flowmeter and pressure transmitter are existing mature technologies, and their structural principles are not elaborated here.

[0039] In this embodiment, the device is a standardized modular unit with a single module length of 2-3m. It is detachably connected in series with the straight pipe section of the mud conveying pipeline 6 through the flange connection component 3. Its modular setting can be flexibly installed in the straight pipe section (each section is 2-3m) to adapt to different engineering scenarios, thereby reducing the area occupied by the concentration tank and odor pollution, and reducing the subsequent dehydration treatment costs.

[0040] It should be noted that the present invention achieves simultaneous dehydration during transportation through a double-layer pipeline structure (external pipeline + filter cloth inner pipeline) and dynamic pressure regulation. At the same time, the concentration of mud is also simultaneously increased during transportation, solving the problems of large footprint and low efficiency of traditional thickening tanks. It has significant economic and environmental benefits and is suitable for space-constrained scenarios such as urban river and lake sediment treatment.

[0041] In the present invention, the inner pipe adopts elastic water-permeable filter cloth, and the lateral pressure is generated by the contraction of the pipe diameter to squeeze the interstitial water. The outer pipe collects overflow water and prevents splashing pollution. Its monitoring system can adjust the flow rate and pressure in real time to ensure continuous and stable operation.

[0042] Example 2

[0043] The present invention also proposes a method for increasing the concentration of mud in a pipeline, so that when the mud flows through the inner pipeline 2, the pipe diameter is reduced, the flow rate is accelerated, the lateral pressure is increased, and the interstitial water is squeezed out by the filter cloth and discharged through the overflow hole of the outer pipeline, thereby achieving the treatment effect of the mud: The specific operation of this method is as follows:

[0044] (a) A target section of the straight section of the slurry conveying pipeline 6 is cut and replaced with the device. During the process of conveying slurry through the pipeline, lateral pressure is generated on the pipe wall. Therefore, a portion of the straight section of the pipeline is selected, each section is about 2 to 3 meters long, and the original pipeline is replaced with a stretchable and permeable filter cloth. The diameter of the inner pipe composed of the filter cloth is slightly smaller than the diameter of the slurry conveying pipeline.

[0045] (b) When the mud flows through the inner pipe 2, the flow rate increases due to the contraction of the pipe diameter, and the lateral pressure of the mud on the pipe wall increases to 0.2-0.8 MPa, forcing the interstitial water to penetrate the filter cloth and enter the outer pipe cavity; when the mud is transported in the pipeline, the inner diameter of the pipeline decreases, the flow rate increases, and the lateral pressure on the pipeline increases. When the mud particle size is larger than the pore size of the filter cloth, the lateral pressure will squeeze out the interstitial water in the mud and retain the mud particles in the pipeline. As the mud is continuously transported in the mud pipeline, the interstitial water originally existing in the mud is continuously squeezed out of the inner pipe, and the concentration of the mud will continue to increase, thereby achieving the purpose of increasing its concentration during the mud pipeline transportation process;

[0046] (c) The interstitial water is directed through the overflow hole 5 of the outer pipe 1 to the residual water treatment device 8. At the same time, the monitoring system 4 is used to dynamically adjust the power of the delivery pump to maintain the pipeline pressure fluctuation amplitude ≤±10% to prevent delivery interruption due to head loss. The outer pipe 1 has the following functions: first, it prevents the splashing of squeezed water, facilitating collection and treatment; second, the gap formed inside and outside the outer pipe can serve as a channel for the interstitial water in the mud. The interstitial water can flow out of the device through the overflow hole 5 on the outer pipe and be collected at the same time. In addition, the monitoring device 4 effectively monitors the flow rate and pressure of the mud in the pipeline, thereby preventing the pressure drop in the pipeline caused by changes in mud concentration and head loss, which may affect the delivery of mud to the designated location;

[0047] (d) The dehydrated slurry particles form a concentration gradient in the inner pipe 2, and the final output concentration is 1.5-3 times higher than the inlet concentration.

[0048] It should be noted that in step (b), lateral pressure is controlled by selecting a filter cloth pore size that matches the slurry particle size distribution; and adaptively adjusting the filtration flux through elastic deformation of the inner pipe, with the deformation range controlled within 5%-15% of the pipe diameter to ensure a balance between slurry particle retention and interstitial water extrusion. Furthermore, in step (c), the residual water treatment device includes a sedimentation tank and a flocculant dosing unit, and the overflow water suspended solids retention rate is ≥95%.

[0049] Example 3: Application of river dredging project

[0050] In a riverbed sediment treatment project, the initial concentration of the sludge was 6%, and the following solution was adopted:

[0051] The mixer is used for a 600m³ / h cutter suction dredger with a DN200 inner diameter mud discharge pipeline, a slurry concentration of 6%, and a pipeline pressure of 400kPa. This embodiment connects a section of this device between the mud discharge pipelines to increase the mud concentration in the pipeline. The specific method is as follows:

[0052] (1) The pipes in the inner tube mud filtration system are made of polyester filter cloth with a diameter of 200 cm and a length of 20 m. The pipes have a heat resistance temperature of 120°C, a breaking elongation of 20%, a softening point of 245°C, and a melting point of 255°C.

[0053] (2) The external pipe overflow anti-splash collection system consists of PVC pipes with a diameter of 210;

[0054] (3) Connect the inner pipe of the device to the mud discharge pipeline through the flange.

[0055] Through field application, the mud concentration increased from 6% to 14% after passing through this system, and the overflow liquid was discharged through the external pipe overflow liquid splash collection system. The overflow water recovery rate was 97%, and the water quality after treatment reached the GB 8978-1996 Class I standard. In addition, during the field application process, the entire system was easy to operate and disassemble, and it was convenient for layout and transfer, thus achieving the purpose of increasing the mud concentration.

[0056] The above descriptions and embodiments are provided to facilitate understanding and application of the present invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these contents and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above descriptions and embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should fall within the scope of protection of the present invention.

Claims

1. A device for increasing the concentration of mud in a pipeline, characterized in that: include: An outer pipe, having a plurality of overflow holes evenly distributed on its wall, the overflow holes being connected to the residual water treatment device through a diversion pipeline; The inner pipe is coaxially nested inside the outer pipe, is made of a filter cloth material with water permeability and elastic deformation ability, and has an inner diameter smaller than the nominal inner diameter of the mud conveying pipe; Flange connection components, symmetrically arranged at both ends of the device, for achieving a sealed connection between the inner pipe and the mud conveying pipe; The monitoring system is integrated into the mud conveying pipelines at the inlet and outlet of the device and includes an electromagnetic flowmeter and a pressure transmitter for real-time collection of mud flow rate and pipeline pressure data.

2. The device for increasing the slurry concentration in a pipeline according to claim 1, characterized in that: The filter cloth material of the inner pipe is selected from polyester or polypropylene polyester fiber braid, and the pore size of the filter cloth is smaller than the minimum particle size of the mud particles.

3. The device for increasing the slurry concentration in a pipeline according to claim 1, characterized in that: The outer pipe is a rigid pipe body, whose inner diameter is 5-20 cm larger than the outer diameter of the inner pipe. The pipe body is made of PVC, HDPE or seamless steel pipe, and its length is equal to that of the inner pipe and completely covers the inner pipe.

4. The device for increasing the slurry concentration in a pipeline according to claim 1, characterized in that: The device is a standardized module unit, with a single module length of 2-3m, and is detachably connected in series with the straight pipe section of the mud conveying pipeline through a flange connection component.

5. A method for increasing the concentration of mud in a pipeline, characterized in that: The method is based on the device for increasing the mud concentration in a pipeline according to any one of claims 1 to 4, comprising the following steps: (a) In a straight section of a slurry conveying pipeline, a target pipe section is cut off and replaced with the device; (b) When the mud flows through the inner pipe, the flow velocity increases due to the contraction of the pipe diameter, and the lateral pressure of the mud on the pipe wall increases to 0.2-0.8 MPa, forcing the interstitial water to penetrate the filter cloth and enter the outer pipe cavity; (c) Directly guide interstitial water to the residual water treatment device through the overflow hole of the external pipeline. At the same time, the monitoring system is used to dynamically adjust the power of the delivery pump to maintain the pipeline pressure fluctuation amplitude and prevent delivery interruption due to head loss; (d) The dehydrated mud particles form a concentration gradient in the inner pipe, and the final output concentration is 1.5-3 times higher than the inlet concentration.

6. The method for increasing the slurry concentration in a pipeline according to claim 5, characterized in that: In step (b), the lateral pressure is regulated by: Select the matching filter cloth pore size according to the mud particle size distribution; The filtration flux is adaptively adjusted through the elastic deformation of the inner pipe, and the deformation range is controlled within 5%-15% of the pipe diameter to ensure a balance between mud particle retention and interstitial water extrusion.

7. The method for increasing the slurry concentration in a pipeline according to claim 5, characterized in that: In step (c), the residual water treatment device includes a sedimentation tank and a flocculant addition unit.

Images