Coal slurry preparation system with cleaning pipeline

Abstract

A coal slurry preparation system with a cleaning pipeline comprises a coal mill, and an inlet of the coal mill is connected with a raw material water pipeline and a raw material coal metering scale; the outlet of the coal mill is also communicated with a sediment pool; the flushing pipeline is used for flushing a pipeline in the coal slurry preparation system and the low-pressure coal slurry pump; an inlet of the pipeline flow direction switching device is communicated with an outlet of the low-pressure coal slurry pump; the pipeline flow direction switching device has a first working state and a second working state; when the pipeline flow direction switching device is in the first working state, qualified coal slurry is smoothly output into the large coal slurry tank; the pipeline flow direction switching device is located in a second working state, and waste water obtained after flushing is discharged into the sediment pool; therefore, by arranging the pipeline flow direction switching device capable of automatically switching the flow direction of the outlet of the low-pressure coal slurry pump, discharged qualified materials and generated waste materials can be reasonably planned to a specified discharging area, and the effects of improving the production efficiency and reducing the maintenance difficulty are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of coal slurry gasification, in particular to a coal slurry preparation system with a cleaning pipeline. Background Art

[0002] GE's water-coal slurry gasification technology is widely used as a key technology in gasification plant production, typically using approximately 60% water-coal slurry as the raw material. However, despite its important role in the gasification industry, its daily operation still faces some urgent challenges.

[0003] First, when a low-pressure coal slurry pump fails, the existing system cannot respond automatically and manual intervention is required to stop the coal slurry system. Moreover, due to the lack of an effective automatic flushing mechanism, the coal slurry easily settles in the pipeline and blocks the pipeline, which not only increases the difficulty of maintenance but also poses a threat to production continuity.

[0004] In addition, during the startup phase of the coal slurry preparation system, a large amount of substandard coal slurry is often produced. These coal slurries are usually discharged into the sedimentation tank, which not only causes waste of raw coal, but also poses challenges to the rational use of resources and cost control. Summary of the Invention

[0005] In response to the above technical problems, the present invention provides a coal slurry preparation system with a cleaning pipeline. By setting a pipeline flow direction switching device that can autonomously switch the flow direction of the low-pressure coal slurry pump outlet, the pipeline flow direction switching device is used to ensure that the discharged qualified materials and the generated waste materials can be reasonably planned to the specified discharge area by switching the working position of the pipeline flow direction switching device. In this way, the present invention plays a role in improving the production efficiency of the gasification workshop and reducing the difficulty of maintenance.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical means:

[0007] A coal slurry preparation system with a cleaning pipeline includes a coal mill, the coal mill having a coal mill inlet and a coal mill outlet connected to each other; the coal mill inlet is connected to a raw water pipeline and a raw coal metering scale for inputting raw coal slurry; the coal mill outlet is connected to a large coal slurry tank via a low-pressure coal slurry pump for collecting qualified coal slurry after processing; the coal mill outlet is also connected to a sludge tank for collecting waste; the coal slurry preparation system also includes:

[0008] a flushing pipe connected between the coal mill outlet and the low-pressure coal slurry pump inlet via a first flushing water shut-off valve, for flushing the pipes in the coal slurry preparation system and the low-pressure coal slurry pump;

[0009] a pipeline flow direction switching device, the inlet of which is connected to the outlet of the low-pressure coal slurry pump; the pipeline flow direction switching device has a first working state and a second working state, and is used to enable the coal slurry preparation system to adjust the discharge outlet of different materials;

[0010] The pipeline flow direction switching device is in the first working state, and the low-pressure coal slurry pump is only connected to the large coal slurry tank, so that the qualified coal slurry is smoothly output to the interior of the large coal slurry tank;

[0011] The pipeline flow direction switching device is in the second working state, and the low-pressure coal slurry pump is only connected to the sedimentation tank, so that the flushed wastewater is discharged into the interior of the sedimentation tank.

[0012] A large coal slurry tank inlet shut-off valve is provided on the discharge pipe connected between the pipeline flow direction switching device and the large coal slurry tank, and the large coal slurry tank inlet shut-off valve is used to control whether the discharge pipe is connected.

[0013] A waste pipeline connected between the pipeline flow direction switching device and the sedimentation tank is provided with a sedimentation tank shut-off valve, and the sedimentation tank shut-off valve is used to control whether the waste pipeline is connected.

[0014] The pipeline flow direction switching device also includes a third working state;

[0015] The pipeline flow direction switching device is in the third working state, and the low-pressure coal slurry pump is only connected to the inlet of the coal mill through the return pipe, so that the initially unqualified coal slurry is sent back to the inlet of the coal mill along the return pipe.

[0016] The flushing pipe is also connected between the outlet of the low-pressure coal slurry pump and the inlet of the coal mill through a second flushing water cut-off valve for flushing the return pipe.

[0017] A reflux shut-off valve is provided on the reflux pipeline communicating between the pipeline flow direction switching device and the coal mill inlet, for controlling whether the pipeline flow direction switching device is communicated with the coal mill inlet.

[0018] A pipeline low-point drain valve is provided on the pipeline communicating between the outlet of the low-pressure coal slurry pump and the inlet of the pipeline flow direction switching device, which is used to discharge the sewage remaining in the pipeline.

[0019] Beneficial effects:

[0020] 1. The utility model provides a pipeline flow direction switching device that can autonomously switch the flow direction of the low-pressure coal slurry pump outlet. The pipeline flow direction switching device is used to ensure that both the discharged qualified materials and the generated waste materials can be reasonably planned to the specified discharge area by switching the working position of the pipeline flow direction switching device. In this way, the utility model plays a role in improving the production efficiency of the gasification workshop and reducing the difficulty of maintenance.

[0021] 2. The utility model sets a return pipe so that the low-pressure coal slurry pump can be connected only to the inlet of the coal mill; therefore, the utility model can remotely start the low-pressure coal slurry pump through the staff, so that the initial unqualified coal slurry is sent back to the inlet of the coal mill along the return pipe; thereby, the utility model saves the raw coal wasted in the startup stage of the coal slurry preparation system, and also improves the rational utilization of resources and cost control. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of the coal slurry preparation system of the utility model.

[0023] In the figure: 1. Coal mill; 2. Mill outlet trough; 3. Pneumatic plunger discharge valve; 4. First flushing water shut-off valve; 5. First flushing pipeline; 6. Low-pressure coal slurry pump; 7. Pipeline low point drain valve; 8. Shut-off valve for inlet to large coal slurry tank; 9. Shut-off valve to sludge tank; 10. Backflow shut-off valve; 11. Second flushing water shut-off valve; 12. Second flushing pipeline; 13. Central controller; 14. Raw water; 15. Raw coal weighing scale; 16. Large coal slurry tank; 17. Sludge tank. DETAILED DESCRIPTION

[0024] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] The structural diagram of a coal slurry preparation system with a cleaning pipeline in the utility model is as follows Figure 1 shown.

[0026] A coal slurry preparation system with a cleaning pipeline includes a coal mill, the coal mill having a coal mill inlet and a coal mill outlet connected to each other; the coal mill inlet is connected to a raw water pipeline and a raw coal metering scale for inputting raw coal slurry; the coal mill outlet is connected to a large coal slurry tank via a low-pressure coal slurry pump for collecting qualified coal slurry after processing; the coal mill outlet is also connected to a sludge tank for collecting waste materials; the coal slurry preparation system also includes:

[0027] The flushing pipeline designed in this application is designed to address the problem of being unable to automatically clean the coal slurry pipeline when a low-pressure coal slurry pump fails. The flushing pipeline designed in this application is connected between the coal mill outlet and the low-pressure coal slurry pump inlet through a first flushing water shut-off valve. It is used to flush the pipelines and low-pressure coal slurry pump within the coal slurry preparation system, allowing the flushed wastewater to flow through the pipeline to the switching device and into the sedimentation tank. Specifically, the flushing pipeline in this case is the first flushing pipeline, which uses 1.1MPa low-pressure flushing gray water to complete the flushing of the pipeline.

[0028] The present application also designs a pipeline flow direction switching device, the inlet of which is connected to the outlet of the low-pressure coal slurry pump; the pipeline flow direction switching device has a first working state and a second working state;

[0029] Among them, the pipeline flow direction switching device is in the first working state, and the low-pressure coal slurry pump is only connected to the large coal slurry tank; among them, specifically, the discharge pipe connecting the pipeline flow direction switching device and the large coal slurry tank is provided with a large coal slurry tank inlet shut-off valve; therefore, when the pipeline flow direction switching device is in the first working state, the large coal slurry tank inlet shut-off valve controls the discharge pipe to be connected, and other channels are closed.

[0030] The pipeline flow direction switching device is in the second working state, and the low-pressure coal slurry pump is only connected to the sedimentation tank; specifically, a sedimentation tank shut-off valve is provided on the waste pipeline connected between the pipeline flow direction switching device and the sedimentation tank; therefore, when the pipeline flow direction switching device is in the second working state, the sedimentation tank shut-off valve controls the waste pipeline to be connected, and other channels are closed.

[0031] By doing so, the operation of the coal slurry preparation system after the transformation of this application is realized with automatic control, which improves the operational flexibility and emergency measures, reduces the labor intensity of personnel, makes the system operation safer, more reliable, and the system operation more flexible.

[0032] The pipeline flow direction switching device also includes a third operating state. When in this state, the low-pressure coal slurry pump is connected only to the pulverizer inlet via the return line, allowing initially unqualified coal slurry to be returned to the pulverizer inlet along the return line. A return line connecting the pipeline flow direction switching device and the pulverizer inlet is provided with a return line shutoff valve. This valve allows the present application to control whether the pipeline flow direction switching device is connected to the pulverizer inlet.

[0033] To facilitate cleaning of the return pipe, the flushing pipe designed in this application is also connected between the low-pressure coal slurry pump outlet and the coal mill inlet through a second flushing water shut-off valve to flush the return pipe. Specifically, the flushing pipe is the second flushing pipe, which uses 1.1MPa low-pressure flushing gray water to complete the flushing of the pipe.

[0034] At the same time, in order to facilitate the discharge of sewage, a pipeline low-point drain valve is provided on the pipeline connecting the outlet of the low-pressure coal slurry pump and the inlet of the pipeline flow direction switching device, which is used to discharge the sewage remaining in the pipeline; when the pipeline low-point drain valve is opened, the sewage remaining in the pipeline will be gradually discharged under the influence of gravity.

[0035] Working principle:

[0036] During normal startup:

[0037] First, the qualified coal slurry produced by the coal mill enters the mill outlet trough, and the staff in the control room remotely opens the pneumatic plunger discharge valve and the reflux shut-off valve through the central controller (DCS system); then, the staff remotely starts the low-pressure coal slurry pump, at which point the initially unqualified coal slurry is sent back to the coal mill inlet along the reflux pipe.

[0038] Next, the DCS system automatically adjusts the amount of raw water and raw coal on the scales, and then calculates the amount of coal slurry returned by the low-pressure coal slurry pump until the coal slurry in the pulverizer meets the qualified standards.

[0039] Finally, after the coal slurry is qualified, the DCS system opens the shut-off valve into the large coal slurry tank, allowing the coal slurry to enter the large coal slurry tank; then, the return water shut-off valve automatically closes, the second flushing water shut-off valve opens, and the second flushing pipe flushes the entire pipeline; after the flushing of the return pipeline is completed, the flushing water shut-off valve will automatically close.

[0040] During normal parking:

[0041] First, the DCS system automatically shuts down the raw water, raw coal scale, coal mill and low-pressure coal slurry pump.

[0042] Then, the DCS system automatically closes the pneumatic plunger discharge valve and the large coal slurry tank shut-off valve; and opens the sludge tank shut-off valve and the first flushing water shut-off valve; at this time, the low-pressure flushing ash water enters the low-pressure coal slurry pump inlet from the first flushing pipe, completing the cleaning of the entire pipeline.

[0043] Next, the DCS system starts the low-pressure coal slurry pump, waits for the equipment and pipelines to be flushed for 30 minutes, and then shuts down the low-pressure coal slurry pump and closes the first flushing water shut-off valve.

[0044] When the low-pressure coal slurry pump stops due to a fault:

[0045] First, the DCS system automatically shuts down the raw water, raw coal scale, coal mill and low-pressure coal slurry pump.

[0046] The system then automatically closes the pneumatic plunger discharge valve and the large coal slurry tank shutoff valve, and opens the sludge tank shutoff valve and the first flushing water shutoff valve. At this point, 1.1 MPa low-pressure flushing ash water flows from the first flushing pipeline into the low-pressure coal slurry pump inlet. Because the low-pressure ash water maintains a pressure of 1.1 MPa, it flushes the coal slurry in the pump and pipeline into the sludge tank. Once the slurry settles, the coal can be recycled.

[0047] Then, after one hour of overall flushing, the DCS system automatically closes the first flushing water shut-off valve; at this time, the operator goes to the site to manually open the drain valve at the low point of the pipeline to drain the sewage in the pipeline.

Claims

1. A coal slurry preparation system with a cleaning pipeline, comprising a coal mill, wherein the coal mill has a coal mill inlet and a coal mill outlet connected to each other; the coal mill inlet is connected to a raw water pipeline and a raw coal metering scale for inputting raw coal slurry; the coal mill outlet is connected to a large coal slurry tank via a low-pressure coal slurry pump for collecting qualified coal slurry after processing; the coal mill outlet is also connected to a sludge tank for collecting waste; characterized in that: The coal slurry preparation system also includes: a flushing pipe connected between the coal mill outlet and the low-pressure coal slurry pump inlet via a first flushing water shut-off valve, for flushing the pipes in the coal slurry preparation system and the low-pressure coal slurry pump; a pipeline flow direction switching device, the inlet of which is connected to the outlet of the low-pressure coal slurry pump; the pipeline flow direction switching device has a first working state and a second working state, and is used to enable the coal slurry preparation system to adjust the discharge outlet of different materials; The pipeline flow direction switching device is in the first working state, and the low-pressure coal slurry pump is only connected to the large coal slurry tank, so that the qualified coal slurry is smoothly output to the interior of the large coal slurry tank; The pipeline flow direction switching device is in the second working state, and the low-pressure coal slurry pump is only connected to the sedimentation tank, so that the flushed wastewater is discharged into the interior of the sedimentation tank.

2. The coal slurry preparation system with a cleaning pipeline according to claim 1, characterized in that: A large coal slurry tank inlet shut-off valve is provided on the discharge pipe connected between the pipeline flow direction switching device and the large coal slurry tank, and the large coal slurry tank inlet shut-off valve is used to control whether the discharge pipe is connected.

3. The coal slurry preparation system with a cleaning pipeline according to claim 1, characterized in that: A waste pipeline connected between the pipeline flow direction switching device and the sedimentation tank is provided with a sedimentation tank shut-off valve, and the sedimentation tank shut-off valve is used to control whether the waste pipeline is connected.

4. The coal slurry preparation system with a cleaning pipeline according to claim 1, characterized in that: The pipeline flow direction switching device also includes a third working state; The pipeline flow direction switching device is in the third working state, and the low-pressure coal slurry pump is only connected to the inlet of the coal mill through the return pipe, so that the initially unqualified coal slurry is sent back to the inlet of the coal mill along the return pipe.

5. The coal slurry preparation system with a cleaning pipeline according to claim 4, characterized in that: The flushing pipe is also connected between the outlet of the low-pressure coal slurry pump and the inlet of the coal mill through a second flushing water cut-off valve for flushing the return pipe.

6. The coal slurry preparation system with a cleaning pipeline according to claim 5, characterized in that: A reflux shut-off valve is provided on the reflux pipeline communicating between the pipeline flow direction switching device and the coal mill inlet, for controlling whether the pipeline flow direction switching device is communicated with the coal mill inlet.

7. The coal slurry preparation system with a cleaning pipeline according to claim 1, characterized in that: A pipeline low-point drain valve is provided on the pipeline communicating between the outlet of the low-pressure coal slurry pump and the inlet of the pipeline flow direction switching device, which is used to discharge the sewage remaining in the pipeline.

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