Coal-water mixed pipe transportation multistage metering dewatering system

Abstract

The utility model provides a coal-water mixing pipeline transportation multistage metering separation system which is composed of a front-end mixing unit, a pipeline transportation unit and a terminal separation unit. The front-end mixing unit comprises a stirring tank, a pulverized coal supply device and a water supply pipeline, the pulverized coal supply device accurately measures the amount of pulverized coal through a built-in weighing sensor, the water supply pipeline regulates and controls the water amount through an electromagnetic flowmeter, and a vertical conveying pipeline is arranged in the stirring tank and connected with a high-pressure coal slurry pump. The pipeline conveying unit is provided with an electromagnetic flowmeter and a concentration meter for monitoring data in real time. The terminal dewatering and separating unit integrates a double-station dewatering and separating device and a centrifugal dewatering machine, the dewatering and separating device realizes primary separation and centrifugal dewatering of coal water through a transverse conveying belt with a pressure sensor, and separated water is recycled or discharged after turbidity detection. The system achieves full-process automatic control through a PLC, it is guaranteed that the coal quantity error is smaller than or equal to 1.2% through a multi-stage metering device, the water recycling rate is larger than or equal to 75%, continuous production is guaranteed through double-station alternate operation, and the system has the characteristics of efficient dehydration, accurate metering, environmental protection and water saving.

Description

Technical Field

[0001] This utility model belongs to the field of coal-water transportation metering technology, specifically relating to a multi-stage metering and separation system for coal-water mixed pipeline transportation. Background Technology

[0002] In coal-water mixed pipeline transportation systems, dry coal powder has poor fluidity and is prone to accumulating or clogging pipelines. Coal-water mixed pipeline transportation systems utilize a coal slurry prepared by mixing coal powder with water, which is then transported through pipelines to the terminal for separation and utilization. Adding water to the coal (forming a coal-water slurry) creates a slurry in which coal particles are uniformly suspended, allowing for long-distance, continuous, and stable pipeline transportation via pumping. Water acts as a lubricating medium, reducing friction between coal particles and the pipe walls, thus lowering energy consumption and pipeline wear. Dry coal powder easily forms explosive mixtures in air; adding water eliminates the risk of dust explosions. Furthermore, wet coal slurry does not generate dust during transportation and loading / unloading, meeting environmental protection requirements. Multi-stage metering and separation systems refer to integrated devices that measure the coal-water volume in real time during transportation and perform graded dewatering and water treatment at the terminal. In existing technologies, traditional systems generally employ a single metering mode (usually dynamic), which suffers from problems such as large coal metering errors (±3% or more), high moisture content after dewatering (>20%), and low water reuse rate (<50%). Furthermore, single-line operations require shutdown for material removal, resulting in poor production continuity. In addition, these systems consume high energy and waste significant water resources, making it difficult to meet the demands of continuous industrial production. There is an urgent need to develop innovative systems with precise metering, efficient dewatering, water recycling, and continuous operation capabilities to overcome technological bottlenecks and reduce operating costs. Utility Model Content

[0003] In view of the defects and problems existing in the prior art, the purpose of this utility model is to provide a multi-stage metering and separation system for coal-water mixed pipeline transportation. Through multi-stage metering control, it solves the problems of large metering errors, serious water waste and low separation efficiency in traditional coal slurry transportation, and realizes high-precision metering, water recycling and continuous and efficient dewatering production.

[0004] The solution to the technical problem of this utility model is as follows: a multi-stage metering and separation system for coal-water mixing pipeline transportation is adopted, including a front-end mixing unit, a pipeline transportation unit, and a terminal separation unit; the front-end mixing unit includes a mixing tank, a pulverized coal supply device, and a water supply pipeline; the pulverized coal supply device is fixed to the side of the mixing tank and its top is connected to the upper inlet of the mixing tank, and a pre-loaded weighing sensor is integrated inside; the water supply pipeline is connected to the upper side wall of the mixing tank, and a pre-loaded electromagnetic flow meter and a water flow regulating valve are installed on the pipeline; a variable frequency agitator is installed on the top of the mixing tank, and a transportation pipeline is vertically fixed to the inner wall of the tank cavity, with the inlet of the transportation pipeline extending to the bottom of the tank. The unit is divided into several parts, with the outlet connected to a high-pressure coal slurry pump. The pipeline conveying unit includes a high-pressure coal slurry pump and a conveying pipeline. The high-pressure coal slurry pump is a plunger-type structure, and the flow rate is adjusted by a frequency converter. The outer wall of the conveying pipeline is covered with a wear-resistant layer, and a central electromagnetic flow meter and a concentration meter are installed on the pipeline. The terminal separation unit includes a separation device, a centrifugal dewatering machine, and a coal-water tank. The coal-water tank is located at the bottom of the separation device. The centrifugal dewatering machine includes a cylindrical shell, a mesh drum, a drive motor, and an annular water cavity. The top opening of the mesh drum is connected to the discharge port of the coal-water tank. An annular water cavity is formed between the drum and the cylindrical shell. The bottom of the annular water cavity is drained by a drainage pump.

[0005] Preferably, the separating device includes a transverse conveyor belt, a mesh guide trough, a plate guide trough, a hopper, and a pressure sensor, wherein the hopper is connected to a conveying pipeline; and the pressure sensor is integrated into the bottom support of the transverse conveyor belt.

[0006] Preferably, the terminal separation unit includes a single-station or dual-station separation device. The alternating control component of the dual-station separation device includes: an electromagnetic three-way valve connected between the outlet of the high-pressure coal slurry pump and the hoppers of the two stations; and a PLC controller that controls the current working unit to pause for t seconds to complete static weighing before switching to another unit.

[0007] Preferably, the bottom of the mesh drum is connected to a coal slurry pump via a slurry extraction pipe.

[0008] Preferably, the transverse conveyor belt of the screen weighing mechanism has a bandwidth of 1200mm and a belt speed adjustable from 0.5 to 2m / s; the inclination angle between the mesh guide trough and the plate guide trough is 45°.

[0009] Preferably, a guide groove is provided between the discharge port of the water-coal box and the top opening of the mesh drum of the centrifugal dewatering machine, and the end of the slurry pumping pipe extends to the bottom of the drum and is connected to the inlet of the coal slurry pump by a flange seal.

[0010] Preferably, the outlet of the coal slurry pump is connected to a plate and frame filter press.

[0011] The beneficial effects of this utility model are:

[0012] 1. Full-process automation and precise control: The system adopts PLC automation control, achieving full automation from coal powder supply, mixing, conveying, separation to water resource recovery. Multi-stage metering devices (such as weighing sensors and flow meters) ensure precise control at each stage, reducing manual intervention and improving efficiency and reliability. The system accurately proportions the coal slurry concentration using weighing sensors and flow meters at the beginning, and monitors and regulates the flow rate in real time during conveying using electromagnetic flow meters and PLC to ensure the uniformity and stability of the coal slurry. At the end, the separation stage efficiently separates coal and water in the slurry through a separation unit and a centrifugal dewatering machine. The centrifugal dewatering machine reduces the coal moisture content from 70% to below 15%. The separated water, after testing and meeting standards, is recycled or discharged, achieving efficient resource utilization and environmental benefits.

[0013] 2. Improved Metering Accuracy: The dual-mode metering mechanism (dynamic + static) achieves dual calibration of coal quantity, reducing errors and improving accuracy compared to traditional single-sensor metering. The dual-position electromagnetic three-way valve cycles through switching, ensuring the dual-mode metering mechanism alternates between transmission and static-focused operation. The centrifugal dewatering machine and separation unit work in tandem, improving separation efficiency. The system is suitable for various coal qualities (clean coal or raw coal), and parameters can be flexibly adjusted according to needs. Each unit has a clear division of labor, facilitating maintenance and repair. It also supports the direct use of dry coal, further improving resource utilization. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of the multi-stage metering and separation system for coal-water mixing pipeline transportation of this utility model;

[0015] Figure 2 This is a block diagram of the multi-stage metering and separation system for coal-water mixing pipeline transportation of this utility model;

[0016] Figure 3 This is a control relationship block diagram of the coal-water mixing pipeline multi-stage metering and separation system of this utility model.

[0017] Labels in the diagram: 1-Water supply pipe; 2-Pulverized coal supply device; 3-Remote gravity sensor; 4-Remote flow meter; 5-High-pressure coal slurry pump; 6-Transportation pipeline; 7-Separation unit; 8-Centrifugal dewatering machine; 9-Coal-water tank; 10-Conveyor belt; 11-Transverse conveyor belt;

[0018] 81-Transverse conveyor belt; 82-Mesh guide trough; 83-Plate guide trough; 84-Hopper; 85-Pressure sensor; 91-Columnar housing; 92-Mesh rotating drum; 93-Drive motor; 94-Annular water chamber; 95-Drainage pipe; 96-Drainage pump or drainage valve; 97-Slurry extraction pipe; 98-Coal slurry pump. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1: A multi-stage metering and separation system for coal-water mixing pipeline transportation includes a mixing tank 1, a coal powder supply device 2, a water supply pipeline 3, a remote weight sensor 4, a remote flow meter 5, a high-pressure coal slurry pump 6, a conveying pipeline 7, a separation unit 8, a centrifugal dewatering machine 9, a coal-water tank 10, and a conveyor belt 11, etc.

[0021] The pulverized coal supply device 2 is fixed close to the mixing tank 1. The top of the pulverized coal supply device 2 is connected to the upper inlet of the mixing tank 1. A water supply pipe 3 is connected to the upper side wall of the mixing tank 1. A remote flow meter 5 is installed on the water supply pipe 3. An agitator is installed on the upper part of the mixing tank 1. A conveying pipe 7 is installed downward along the inner side wall of the top of the mixing tank 1. A high-pressure coal slurry pump 6 is installed on the conveying pipe 7. The near end of the conveying pipe 7 is connected to the inlet of the separation unit 8.

[0022] The separation unit 8 includes a transverse conveyor belt 81, a mesh guide trough 82, a plate guide trough 83, and a hopper 84. The centrifugal dewatering machine 9 includes a cylindrical shell 91, a mesh rotating drum 92, a drive motor 93, an annular water chamber 94, a drain pipe 95, a drain pump or drain valve 96, a slurry pumping pipe 97, and a coal slime pump 98.

[0023] Cleaned coal from coal mines, or raw coal that has been crushed and screened, is fed into a mixing tank or mixer via a conveyor belt or pneumatic conveying system. Water is added to meet the coal slurry mixing requirements (concentration 40%–70%). The coal and water are mixed to form a coal slurry, which is then pumped to its final destination via a high-pressure coal slurry pump. At the end, a metering and separating device separates the coal and water. The process involves: Initial mixing stage: a weighing sensor measures the coal powder, and a flow meter controls the water addition to form a 60% coal slurry; Pipeline conveying stage: an electromagnetic flow meter monitors the real-time flow rate, and a concentration meter feeds back data to a PLC to adjust the pump speed to maintain a stable flow rate; End-of-line separation stage: a metering and separating device, including at least one separating unit and a centrifugal dewatering machine, separates the coal and water in the slurry; the separated water is tested by a turbidity meter, and if it meets the standards, it is introduced back into the initial mixing stage for reuse, or discharged into a return water well.

[0024] The separating unit includes at least one layer of screen weighing mechanism, which includes a transverse conveyor belt 81. A pressure sensor 85 is installed on the bottom support of the transverse conveyor belt 81 to detect the gravity change of the transverse conveyor mechanism to confirm the current coal weight. A mesh guide chute 82 is installed at an incline at the input of the transverse conveyor mechanism. The first section of the mesh guide chute 82 is connected to a hopper 84. The output of the high-pressure coal slurry pump 6 is connected to the hopper 84. A plate guide chute 83 is installed at an incline at the tail end of the transverse conveyor mechanism. The lower end of the plate guide chute 83 is located above the conveyor belt 11. The end of the conveyor belt 11 is connected to a transport vehicle. A coal-water tank 10 is provided at the bottom of the separating unit. A discharge port and a discharge solenoid valve are installed at the bottom of the coal-water tank 10.

[0025] The centrifugal dewatering machine 9 includes a cylindrical outer shell 91. A rotating shaft is installed in the middle of the bottom plate of the cylindrical outer shell 91. A drive motor 93 is connected to the lower part of the rotating shaft. A mesh rotating drum 92 is connected to the upper end of the rotating shaft. The top of the mesh rotating drum 92 is open. An annular water cavity 94 exists between the cylindrical outer shell 91 and the mesh rotating drum 92. A drain pipe 95 is connected to the bottom of the annular water cavity 94. A drain pump or drain valve 96 is installed on the drain pipe 95. The centrifugal dewatering machine 9 reduces the moisture content of coal from 70% to below 15%. The discharge port at the bottom of the coal-water tank 10 is connected to the open top of the mesh rotating drum 92. At the same time, a slurry suction pipe 97 is fixed at the top of the cylindrical outer shell 91. The end of the slurry suction pipe 97 is located at the bottom of the mesh rotating drum 92. The slurry suction pipe 97 is connected to the inlet of the coal slurry pump 98. The outlet of the coal slurry pump 98 is connected to the coal slurry filter press mechanism.

[0026] The system workflow is as follows Figure 2 and Figure 3 As shown: Raw coal crushing → Coal powder supply (remote pressure sensor → controller) → Mixing in a mixing tank (water + coal) → Pipeline transportation (remote flow meter 5 → controller) → Separation unit, separation unit → Screen weighing mechanism (near-end pressure sensor → controller) → Conveyor belt, screen weighing mechanism → Coal slurry water (concentration detector → controller) → Centrifugal dewatering machine → Drain pump or drain valve (near-end flow meter → controller) → Wastewater treatment → Circulating water tank → Recycled to mixing tank; Centrifugal dewatering machine → Coal slime pump 98 → Coal slime filter press mechanism → Dry coal utilization.

[0027] Example 2: A multi-stage metering and separation system for coal-water mixed pipeline transportation, the system composition and structure are as follows. Figures 1-3 As shown in the figure. This system consists of a mixing tank 1, a pulverized coal supply device 2, a water supply pipeline 3, a remote gravity sensor 4, a remote flow meter 5, a high-pressure coal slurry pump 6, a conveying pipeline 7, a separation unit 8, a centrifugal dewatering machine 9, a coal-water tank 10, and a conveyor belt 11. Each unit works together to realize the functions of coal slurry preparation, conveying, and coal-water separation. The specific structure is as follows.

[0028] The front-end mixing system includes a mixing tank 1, a pulverized coal supply device 2, and a water supply pipeline 3. The pulverized coal supply device 2 is fixed to the side of the mixing tank 1, with its top connected to the upper inlet of the mixing tank 1. It has a built-in weighing sensor 4 that monitors the pulverized coal dosage in real time. The water supply pipeline 3 is connected to the upper side wall of the mixing tank 1, and an electromagnetic flow meter 5 is installed in the pipeline. A water flow regulating valve is controlled by a PLC. The mixing tank 1 has a variable frequency agitator at the top, and a conveying pipeline 7 is vertically installed on the inner side wall. The pipeline inlet extends to the bottom of the tank, and the outlet is connected to the conveying pipeline 7 via a high-pressure coal slurry pump 6.

[0029] The conveying pipeline system includes a high-pressure coal slurry pump 6 and a conveying pipeline 7. The high-pressure coal slurry pump 6 employs a plunger-type structure, with an operating pressure range of 2.5-4.0 MPa, and its flow rate is adjusted via a frequency converter. The conveying pipeline 7 has a diameter of DN200-300, is covered with a wear-resistant layer, and is equipped with electromagnetic flow meters and nuclear concentration meters along its route, with data fed back to the PLC in real time. Based on the pipeline length and elevation difference, the pumping pressure compensation value is automatically calculated to prevent slurry deposition.

[0030] The terminal separation system includes a separation unit 8 and a centrifugal dewatering machine 9. The separation unit 8 is a single-station or dual-station design (as in Example 3), including a transverse conveyor belt 81, a mesh guide trough 82, a plate guide trough 83, and a hopper 84. The hopper 84 receives material from the conveying pipe 7 and its bottom is connected to a screen weighing mechanism. The screen weighing mechanism includes a transverse conveyor belt 81 (1200mm wide), a 45° inclined mesh guide trough 82, and a plate guide trough 83. A pressure sensor 85 (accuracy ±0.5%FS) is integrated into the bottom support of the conveyor belt.

[0031] The centrifugal dewatering machine 9 includes a cylindrical outer shell 91, a mesh rotating drum 92, a drive motor 93, an annular water chamber 94, a drain pipe 95, a drain pump or drain valve 96, a slurry extraction pipe 97, and a coal slime pump 98. The mesh rotating drum 92 has a diameter of Φ1600mm, an adjustable speed of 800-1200rpm, and is driven by the bottom drive motor 93. Water recovery structure: An annular water chamber 94 is formed between the rotating drum and the cylindrical outer shell 91. The bottom of the annular water chamber 94 is drained by the drain pump 95, and the separated water (reused when turbidity ≤50NTU) is discharged. Coal slime treatment: The bottom of the rotating drum is connected to the coal slime pump 98 through the slurry extraction pipe 97, and the coal slime is transported to a plate and frame filter press. Water-coal tank 10: Located at the bottom of the separation unit 8, it receives drainage from the mesh feed trough. The discharge port can be controlled by a solenoid valve, and the discharge port is connected to the hollow area at the top of the mesh rotating drum.

[0032] The usage process and operating logic of the above scheme are as follows.

[0033] 1. Coal slurry preparation stage: After being crushed and screened (particle size ≤ 3mm), the raw coal is fed into the mixing tank 1 by a conveyor belt. A remote weight sensor 4 measures the weight of the coal powder, and a remote flow meter 5 regulates the water supply. The mixture is mixed at a 60% concentration ratio. The agitator runs at 120 rpm for ≥ 5 minutes to form a homogeneous coal slurry.

[0034] 2. Pipeline transportation stage: High-pressure coal slurry pump 6 pressurizes the coal slurry to 2.5-4.0 MPa and transports it to the terminal via pipeline 7. The PLC controller dynamically adjusts the pump speed to maintain stable flow rate (deviation ±3%) based on data from electromagnetic flowmeter 5 and concentration meter.

[0035] 3. Terminal Separation Stage: The separation units operate alternately. When Unit A is working, the coal slurry falls from hopper 84 onto the transverse conveyor belt 81, and dynamic weighing data is uploaded in real time. After Unit A pauses for 3 seconds to complete static weighing, it switches to Unit B for feeding. The separated coal (containing 30-40% moisture) falls from the plate-shaped guide chute 83 onto the conveyor belt 11, and is finally loaded for transportation. Enhanced Centrifugal Dewatering: The coarsely separated coal enters the centrifugal dewatering machine 9, where the high-speed rotation of the drum generates a centrifugal force of ≥800G, reducing the moisture content to below 15%. The separated water is reused or discharged after turbidity testing, and the coal slime is treated by pressure filtration by the coal slime pump 98.

[0036] 4. Water Circulation Control: Reclaimed water volume = mixing water requirement - theoretical water content of coal slurry; the PLC automatically calculates the replenishment water volume. Wastewater with turbidity > 50 NTU is introduced into a sedimentation tank and can only be reused after meeting the standards. This system, through optimized process parameters and control logic, achieves a coal conveying metering error ≤ 1.2% and a water reuse rate ≥ 75%, meeting the industrial application requirements of long-distance pipeline transportation of coal slurry.

[0037] Example 3: Based on Example 1 or 2, a dual-mode metering mechanism is adopted, including two parallel separation units and a centrifugal dewatering machine. The output end of the high-pressure pump is connected to the hoppers of the two separation units respectively through an electromagnetic tee connector. The controller is used to control the electromagnetic tee connector to select the output end of the high-pressure pump to connect to one of the separation units to provide coal slurry. The two units work alternately. When the first unit is in the transmission operation, the second unit is in a brief pause state before resuming transmission until it is emptied. The pause state is for static accurate weighing. After accurate weighing, the second unit continues transmission until it is emptied. Then, the controller controls the high-pressure pump to transmit the coal slurry to the hopper at the head of the second unit. The second unit is in the transmission state, while the first unit is in a brief pause state before resuming transmission until it is emptied. The two units thus work alternately.

[0038] When using a dual-station separating unit, alternating control is implemented: The hopper feed is switched via a solenoid three-way valve; the working unit pauses for 3 seconds to complete static weighing before resuming discharge. Dynamic weighing: Continuous weighing (±1.5% accuracy) occurs while the conveyor belt 81 is running. Static weighing: Vibration interference is eliminated when the equipment is paused, achieving high-precision measurement of ±0.5%.

[0039] The specific embodiments described above are merely illustrative or explanatory of the principles of this utility model and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of this utility model should be included within the protection scope of this utility model.

Claims

1. A multi-stage metering and separation system for coal-water mixed pipeline transportation, characterized in that, It includes a front-end mixing unit, a pipeline conveying unit, and a terminal separation unit; the front-end mixing unit includes a mixing tank (1), a pulverized coal supply device (2), and a water supply pipeline (3). The pulverized coal supply device (2) is fixed to the side of the mixing tank (1) and its top is connected to the upper inlet of the mixing tank. It integrates a front-end weighing sensor (4); the water supply pipeline (3) is connected to the upper side wall of the mixing tank (1). A front-end electromagnetic flow meter (5) and a water flow regulating valve are installed on the pipeline; a variable frequency stirrer is installed on the top of the mixing tank (1). A conveying pipeline (7) is vertically fixed to the inner wall of the tank. The inlet of the conveying pipeline (7) extends to the bottom of the tank and the outlet is connected to a high-pressure coal slurry pump (6). The pipeline conveying unit includes a high-pressure coal slurry pump (6) and a conveying pipeline (7). The high-pressure coal slurry pump (6) is a plunger type structure and the flow rate is adjusted by a frequency converter. The outer wall of the conveying pipeline (7) is covered with a wear-resistant layer, and a central electromagnetic flow meter and a concentration meter are installed on the pipeline. The terminal separation unit includes a separation device (8), a centrifugal dewatering machine (9), and a coal-water tank (10). The coal-water tank (10) is located at the bottom of the separation device (8). The centrifugal dewatering machine (9) includes a cylindrical shell (91), a mesh drum (92), a drive motor (93), and an annular water cavity (94). The top opening of the mesh drum (92) is connected to the discharge port of the coal-water tank (10). An annular water cavity (94) is formed between the drum and the cylindrical shell (91). The bottom of the annular water cavity (94) is drained by a drainage pump (95) to discharge separated water.

2. The system according to claim 1, characterized in that, The separation device (8) includes a screen weighing mechanism, which includes a transverse conveyor belt (81), a mesh guide trough (82), a plate guide trough (83), a hopper (84), and a pressure sensor (85). The hopper (84) is connected to the conveying pipe (7). The pressure sensor (85) is integrated into the bottom support of the transverse conveyor belt.

3. The system according to claim 2, characterized in that, The terminal separation unit includes a single-station or dual-station separation device (8). The alternating control components of the dual-station separation device (8) include: an electromagnetic three-way valve connected between the outlet of the high-pressure coal slurry pump (6) and the two-station hoppers (84); and a PLC controller that controls the current working unit to pause after completing static weighing and then switch to another unit.

4. The system according to claim 1, characterized in that, The bottom of the mesh drum (92) is connected to the coal slurry pump (98) via the slurry pumping pipe (97).

5. The system according to claim 2, characterized in that, The transverse conveyor belt (81) of the screen weighing mechanism has an adjustable speed of 0.5-2m / s, and the inclination angle between the mesh guide trough (82) and the plate guide trough (83) is 45°.

6. The system according to claim 4, characterized in that, A guide channel is provided between the discharge port of the coal-water tank (10) and the top opening of the mesh drum (92) of the centrifugal dewatering machine (9), and the end of the slurry pumping pipe (97) extends to the bottom of the drum and is connected to the inlet of the coal slurry pump (98) by a flange seal.

7. The system according to claim 4, characterized in that, The outlet of the coal slurry pump (98) is connected to a plate and frame filter press.

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