Long-distance, high-capacity and airtight pulverized coal concentrated-phase pneumatic conveying system
By designing a long-distance, large-capacity, and airtight coal-pulverized thick-phase pneumatic conveying system, the limitation, uniformity, dust-free start and stop problems in the existing coal-pulverized conveying process are solved, and the secondary dust and environmental pollution problems are achieved, efficient and low-cost coal-pulverized conveying is achieved.
Patent Information
- Application Number
- CN202422320077.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-09-23
AI Technical Summary
The existing coal powder conveying process has problems such as limiting, uniformity, dust-free start and stopping of mechanical components, resulting in frequent equipment failures and inability to achieve sealed conveying, and secondary dust and environmental pollution problems.
Long-distance, large-capacity, and airtight coal-pulverized thick-phase pneumatic conveying system, including a conveying pump, a long-distance conveying pipeline and a coal-pulverized storage tank, is adopted to achieve closed conveying through nitrogen fluidization and control valve design.
Long-distance, large-capacity and closed transportation of coal powder is realized, which avoids secondary dust and environmental pollution, improves transportation capacity and efficiency, and reduces operating costs.
Smart Images
Figure CN223002345U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a pulverized coal dense-phase pneumatic conveying system for long-distance, large-capacity and airtight conveying, belonging to the field of pulverized coal pneumatic conveying. Background Art
[0002] China is rich in coal reserves but lacks gas resources. The pulverized coal pressurized gasification technology is highly promoted because of its advantages such as advanced process, low investment, strong adaptability to raw coal, low operation and maintenance cost, and less environmental pollution, which well meets the needs of the development of clean energy in China. Generally, raw coal is weighed from the raw coal storage bin, then ground into pulverized coal by a coal mill, dried and temporarily stored in the pulverized coal buffer bunker. Then, the pulverized coal is mechanically conveyed into a designated pulverized coal storage tank by a screw feeder, a scraper conveyor, a bucket elevator and a suction and discharge vehicle, waiting to be finally fed into a gasifier for pressurized gasification. In the above entire process flow, the method of mechanically conveying pulverized coal is restricted by the mechanical components of the equipment itself, and it must achieve uniform conveying, dust-free start and dust-free stop. Otherwise, problems such as jamming and damage are likely to occur, and equipment failures frequently occur during actual implementation. In addition, the above process of conveying pulverized coal cannot achieve sealing, there is a problem of secondary dust emission, resulting in environmental pollution and low work efficiency. It can be seen that these problems need to be solved urgently. Summary of the Utility Model
[0003] The purpose of the utility model is to provide a pulverized coal dense-phase pneumatic conveying system for long-distance, large-capacity and airtight conveying, which realizes long-distance, large-capacity and airtight conveying of pulverized coal, has no pollution, high efficiency, low cost and is suitable for popularization.
[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:
[0005] A pulverized coal dense-phase pneumatic conveying system for long-distance, large-capacity and airtight conveying, comprising a conveying pump. The top inlet of the conveying pump is connected to the bottom outlet of the pulverized coal buffer bunker, the bottom outlet of the conveying pump is connected to the inlet of the pulverized coal storage tank via a long-distance conveying pipeline. An inlet valve and an outlet valve are respectively installed at the top inlet and the bottom outlet of the conveying pump. An exhaust pipeline is connected between the pump body of the conveying pump and the upper part of the pulverized coal buffer bunker, and a balance valve is arranged on the exhaust pipeline. A bunker fluidization pipeline is connected between the pulverized coal buffer bunker and the air outlet of the nitrogen storage tank, and a bunker fluidization control valve is arranged on the bunker fluidization pipeline. A control pipeline is connected between the air outlet of the nitrogen storage tank and the conveying pump. Among them, the control pipeline includes a main pipeline. The inlet of the main pipeline is connected to the air outlet of the nitrogen storage tank, and the outlet of the main pipeline is divided into two paths. One path is connected to the upper part of the conveying pump via a conveying pipeline, and the other path is connected to the lower part of the conveying pump via a pump fluidization pipeline. A conveying control valve is arranged on the conveying pipeline, and a pump fluidization control valve is arranged on the pump fluidization pipeline.
[0006] The advantages of the present utility model are as follows:
[0007] The present utility model realizes long-distance, large-capacity, and airtight dense-phase conveying of pulverized coal (obtained after the raw coal is ground and dried). The entire conveying process has good sealing performance, no secondary dust-raising problem, no environmental pollution, strong conveying capacity (the conveying capacity exceeds 80 t / h), and long conveying distance (the distance can reach more than 200 m). In addition, the non-mechanical pneumatic conveying method is not restricted by the conveying uniformity, whether the start and stop are dust-free, has no jamming and damage problems, avoids frequent failures, is easy to maintain, has high working efficiency, low operating cost, and is suitable for popularization. Description of the Drawings
[0008] Figure 1 It is a schematic diagram of the composition of the dense-phase pneumatic conveying system for pulverized coal of the present utility model. Detailed Embodiment
[0009] As Figure 1 shown, the present utility model provides a dense-phase pneumatic conveying system for pulverized coal with long-distance, large-capacity, and airtight conveying, which includes a conveying pump 70. The top inlet of the conveying pump 70 is connected to the bottom outlet of the pulverized coal buffer hopper 20, and the bottom outlet of the conveying pump 70 is connected to the inlet of the pulverized coal storage tank 130 via a long-distance conveying pipeline 100. An inlet valve 71 and an outlet valve 72 are respectively installed at the top inlet and the bottom outlet of the conveying pump 70. An exhaust pipeline 90 is connected between the pump body of the conveying pump 70 and the upper part of the pulverized coal buffer hopper 20, and a balance valve 91 is provided on the exhaust pipeline 90. A hopper fluidization pipeline 40 is connected between the pulverized coal buffer hopper 20 and the air outlet of the nitrogen storage tank 50, and a hopper fluidization control valve 41 is provided on the hopper fluidization pipeline 40. A control pipeline is connected between the air outlet of the nitrogen storage tank 50 and the conveying pump 70. Among them, the control pipeline includes a main pipeline 61. The inlet of the main pipeline 61 is connected to the air outlet of the nitrogen storage tank 50, and the outlet of the main pipeline 61 is divided into two paths. One path is connected to the upper part of the conveying pump 70 via a conveying pipeline 62, and the other path is connected to the lower part of the conveying pump 70 via a pump fluidization pipeline 64. A conveying control valve 621 is provided on the conveying pipeline 62, and a pump fluidization control valve 641 is provided on the pump fluidization pipeline 64.
[0010] As Figure 1 , the pulverized coal buffer hopper 20 is a sealed chamber for temporarily storing pulverized coal. The top of the pulverized coal buffer hopper 20 is connected to a feeding pipeline 11 and a centralized dust collection pipeline 12. Among them, the feeding pipeline 11 is used to make the pulverized coal obtained after being ground by a coal mill fall into the pulverized coal buffer hopper 20, and the centralized dust collection pipeline 12 is used to collect the dust-containing gas generated during the feeding, exhaust, and powder return processes into a dust collection tank or the like to avoid dust leakage, purify the environment, and prevent pulverized coal explosion.
[0011] As Figure 1, in the actual design, the outlet of the main pipeline 61 is also connected to the outlet of the outlet valve 72 on the conveying pump 70 via a gas supplement pipeline 63. A gas supplement control valve 631 is provided on the gas supplement pipeline 63. Among them, a main valve 60 is provided at the gas outlet of the nitrogen storage tank 50. That is, the outlet of the main valve 60 is divided into two paths. One path is the bin fluidization pipeline 40 and the other path is the main pipeline 61.
[0012] In practice, the gas inlet of the nitrogen storage tank 50 is connected to a nitrogen source, and an inlet valve 51 is provided at the gas inlet of the nitrogen storage tank 50. In addition, a safety valve, a pressure regulating valve and a blowdown valve should also be installed on the nitrogen storage tank 50. This is a conventional practice, so it will not be elaborated here.
[0013] Such as Figure 1 , further, a filter 611 and a pressure regulating valve 612 are provided on the main pipeline 61. Usually, the filter 611 is in front and the pressure regulating valve 612 is behind. The outlets of the conveying control valve on the conveying pipeline 62, the pump fluidization control valve 641 on the pump fluidization pipeline 64, and the gas supplement control valve 631 on the gas supplement pipeline 63 are all connected with an orifice plate 65 and a check valve 66. The orifice plate 65 is in front and the check valve 66 is behind.
[0014] In the actual design, the outlet of the bin fluidization pipeline 40 is connected to the lower part of the pulverized coal buffer bin 20 through an orifice tube 42. An orifice plate 92 is provided at the outlet of the balance valve 91 on the exhaust pipeline 90.
[0015] In the present utility model, the filter 611 is used to filter impurities from the conveying gas (nitrogen) sent by the nitrogen storage tank 50. The pressure regulating valve 612 is used to adjust the pressure of the conveying gas sent by the nitrogen storage tank 50 to the pressure required for conveying pulverized coal. The orifice plates 65, 92 and the orifice tube 42 are used to control the gas flow rate. Usually, the outlet of the bin fluidization pipeline 40 is divided into multiple branches, and an orifice tube 42 is provided on each branch. The orifice tubes 42 are evenly distributed in the circumferential direction of the outer circumference of the pulverized coal buffer bin 20. The check valve 66 is used to prevent gas backflow. The main valve 60 is used to control the start and stop of pulverized coal conveying and to control the conveying of nitrogen for fluidization. The filter 611, the pressure regulating valve 612, the orifice plates 65, 92 and the orifice tube 42, the check valve 66, etc. are well-known technologies in the art.
[0016] In the actual design, a bin level gauge 30 is installed on the pulverized coal buffer bin 20. The bin level gauge 30 is used to monitor the position of the pulverized coal in the pulverized coal buffer bin 20. Usually, the bin level gauge 30 is installed at the lower part of the pulverized coal buffer bin 20. A pump level gauge 73 is installed on the conveying pump 70. The pump level gauge 73 is used to monitor the position of the pulverized coal in the conveying pump 70. Usually, the pump level gauge 73 is installed at the top of the conveying pump 70. The bin level gauge 30 and the pump level gauge 73 both adopt existing level gauges in the art.
[0017] As Figure 1 A return powder pipeline 80 is connected between the bottom outlet (the inlet of the outlet valve 72) of the conveying pump 70 and the upper part of the pulverized coal buffer bunker 20, and a return powder valve 81 is provided on the return powder pipeline 80.
[0018] In actual design, the outlet part of the conveying pump 70 is in the shape of an arc elbow, that is Figure 1 the indicated part - the arc elbow 701, the inlet valve 71 and the outlet valve 72 are dome valves, and the dome valves can ensure complete sealing isolation between the inside and outside of the pump to ensure airtight conveying.
[0019] Usually, a manual feeding valve for isolation during maintenance is also installed at the bottom outlet of the pulverized coal buffer bunker 20, and is connected to the inlet valve 71 of the conveying pump 70 through a flexible joint (mainly for facilitating the disassembly and assembly of the manual feeding valve and the inlet valve 71 during maintenance). The manual feeding valve, the flexible joint and the dome valve are common components in the art and will not be elaborated here.
[0020] As Figure 1 shown, a conveying elbow 101 is provided at the turning point of the long-distance conveying pipeline 100 itself, a receiving bunker 110 is provided at the inlet of the pulverized coal storage tank 130, an arc-shaped baffle 111 is provided in the receiving bunker 110, wear-resistant ceramics are pasted on the concave surface of the arc-shaped baffle 111, and a dust collector 120 is installed on the top of the pulverized coal storage tank 130. Among them, the inlet end of the arc-shaped baffle 111 corresponds to the outlet of the long-distance conveying pipeline 100, the ceramics on the arc-shaped baffle 111 face the inside of the pulverized coal storage tank 130. Usually, the outlet end of the arc-shaped baffle 111 extends into the pulverized coal storage tank 130, so that the mixture of nitrogen and pulverized coal conveyed through the long-distance conveying pipeline 100 can smoothly enter the pulverized coal storage tank 130 along the arc-shaped baffle 111.
[0021] In actual application, pressure gauges (not shown in the figure) are installed on the pulverized coal buffer bunker 20, the conveying pump 70 and the long-distance conveying pipeline 100. The pressure gauges installed on the pulverized coal buffer bunker 20, the conveying pump 70 and the long-distance conveying pipeline 100 are respectively used to monitor the internal pressures of their own.
[0022] In the present utility model, the conveying elbow 101 is used to reduce the resistance during the conveying of pulverized coal, so that the pulverized coal can smoothly change the direction of conveyance and ensure smooth conveyance. The arc-shaped baffle 111 is used to reduce the resistance so that the pulverized coal can smoothly fall into the pulverized coal storage tank 130. The dust collector 120 is used to discharge the nitrogen mixed in the pulverized coal in the pulverized coal storage tank 130 after dust removal and filtration treatment, so as to avoid directly discharging the gas mixed with pulverized coal dust into the atmosphere to pollute the environment. The conveying elbow 101 and the dust collector 120 adopt existing devices in the art.
[0023] In actual implementation, each valve and equipment are connected to the PLC control system or the DCS control system and are controlled by it, so that the present utility model realizes fully automatic operation and reduces the operation cost.
[0024] In the present utility model:
[0025] The bin hopper fluidization pipeline 40 is used to activate the pulverized coal in the pulverized coal buffer bin hopper 20, avoid phenomena such as blockage and compaction, and ensure smooth material discharge.
[0026] The exhaust pipeline 90 is used to discharge the gas in the conveying pump 70, adjust the pressure difference between the pulverized coal buffer bin hopper 20 and the conveying pump 70, and ensure that the pulverized coal can smoothly fall into the conveying pump 70 by its own weight.
[0027] The powder return pipeline 80 is used to return the pulverized coal in the conveying pump 70 into the pulverized coal buffer bin hopper 20 when there is a blockage in the long-distance conveying pipeline 100 or a downstream equipment failure, playing the role of emptying the pulverized coal and avoiding spontaneous combustion of the pulverized coal.
[0028] The conveying pipeline 62 is used to send the nitrogen in the nitrogen storage tank 50 into the conveying pump 70 to achieve long-distance conveying of the pulverized coal in the conveying pump 70.
[0029] The present utility model adopts a conveying pump 70 in the shape of an inverted triangle, designs an arc elbow 701, and uses globe valves at the inlet and outlet, which makes it possible for large-capacity and long-distance conveying. The volume of the conveying pump 70 adopted by the present utility model is between 8m 3 -11m 3 and it is a large-capacity pump.
[0030] The pump fluidization pipeline 64 is used to activate the pulverized coal in the conveying pump 70, avoid phenomena such as blockage and compaction, and ensure smooth conveying.
[0031] The air supplement pipeline 63 is used to supplement the conveying gas (nitrogen) into the long-distance conveying pipeline 100 when the conveying air power is insufficient to ensure smooth conveying.
[0032] In actual implementation, in addition to nitrogen, other inert gases can also be used to convey the pulverized coal without limitation.
[0033] In the present utility model, the position where the gas arrives first is the front, and the position where it arrives later is the rear.
[0034] The working process of the present utility model is as follows:
[0035] The pulverized coal falls into the pulverized coal buffer hopper 20 through the feeding pipeline 11. The main valve 60 and the hopper fluidization control valve 41 are opened, and the pulverized coal in the pulverized coal buffer hopper 20 is activated. Then the hopper level gauge 30 is covered by the pulverized coal (indicating that there is pulverized coal in the pulverized coal buffer hopper 20), and then the conveying operation is started. The outlet valve 72 remains closed, and the balance valve 91 is opened for a certain period of time to make the pressure in the pulverized coal buffer hopper 20 consistent with that in the conveying pump 70. Then the inlet valve 71 is opened, and the pulverized coal falls into the conveying pump 70 under the action of its own gravity. When the pump level gauge 73 is covered by the pulverized coal (indicating that the amount of pulverized coal in the conveying pump 70 reaches the required amount for conveying, that is, the conveying pump 70 is full), the inlet valve 71 is closed, the balance valve 91 is closed, and then the pump fluidization control valve 641 is opened to activate the pulverized coal in the conveying pump 70. At the same time, the conveying control valve 621 is opened, and the compressed conveying gas (nitrogen) is injected into the conveying pump 70. When the pressure in the conveying pump 70 reaches the threshold value, the air supplement control valve 631 and the outlet valve 72 are quickly opened, and the mixture of pulverized coal and nitrogen is conveyed into the long-distance conveying pipeline 100 and stored in the pulverized coal storage tank 130 through the long-distance conveying pipeline 100. The nitrogen mixed in the pulverized coal stored in the pulverized coal storage tank 130 is filtered and discharged to the outside after passing through the dust collector 120. When the pressure in the long-distance conveying pipeline 100 drops to the set low threshold value, it indicates that there is no pulverized coal in the long-distance conveying pipeline 100, and the conveying is completed. Operate in such a cycle.
[0036] When the pressure in the long-distance conveying pipeline 100 drops to the set empty pipe pressure, the conveying control valve 621, the pump fluidization control valve 641, and the outlet valve 72 are closed, the balance valve 91 is opened, and the air supplement control valve 631 remains open to continue to supplement the conveying gas (nitrogen) to the long-distance conveying pipeline 100 for the purpose of pipeline purging, so as to save the conveying cycle time and improve the conveying capacity.
[0037] When the pulverized coal in the long-distance conveying pipeline 100 is blocked or the downstream equipment (such as the dust collector 120) fails, the powder return valve 81 is opened, and the high pressure in the long-distance conveying pipeline 100 is used to make the pulverized coal in the conveying pump 70 return to the pulverized coal buffer hopper 20 to empty the pulverized coal and avoid spontaneous combustion of the pulverized coal.
[0038] The advantages of the present utility model are:
[0039] The present utility model realizes long-distance, large-capacity, and airtight dense-phase conveying of pulverized coal (obtained after grinding and drying raw coal). The whole conveying process has good sealing performance, no secondary dust raising problem, no environmental pollution, strong conveying capacity (the conveying capacity exceeds 80 t / h), long conveying distance (the distance can reach more than 200 m). In addition, the non-mechanical pneumatic conveying method is not restricted by the conveying uniformity, whether it is dust-free during startup and shutdown, has no jamming and damage problems, avoids frequent failures, is simple to maintain, has high working efficiency, and reduces the dust removal cost.
[0040] In the conveying process of the utility model, the design of conveying elbows and arc-shaped baffles is adopted, which reduces the wear of pulverized coal and improves the conveying quality. The whole conveying process does not require manual operation, has a high degree of automation and low operating costs, and is suitable for popularization. The utility model can be widely applied to occasions such as coal-to-synthetic ammonia, coal-to-methanol and coal-to-oil.
[0041] The above is the preferred embodiment of the utility model and the technical principles applied. For those skilled in the art, any obvious changes such as equivalent transformation and simple replacement based on the technical solution of the utility model without departing from the spirit and scope of the utility model shall fall within the protection scope of the utility model.
Claims
1. A coal powder dense phase pneumatic conveying system for long-distance, large-capacity, closed conveying, characterized in that: The utility model comprises a conveying pump, wherein the top inlet of the conveying pump is connected with the bottom outlet of the coal powder buffer hopper, and the bottom outlet of the conveying pump is connected with the inlet of the coal powder storage tank via a long-distance conveying pipeline, and the top inlet and the bottom outlet of the conveying pump are respectively equipped with an inlet valve and an outlet valve, an exhaust pipeline is connected between the pump body of the conveying pump and the upper part of the coal powder buffer hopper, and a balancing valve is arranged on the exhaust pipeline, a hopper fluidization pipeline is connected between the coal powder buffer hopper and the gas outlet of the nitrogen storage tank, and a hopper fluidization control valve is arranged on the hopper fluidization pipeline, and a control pipeline is connected between the gas outlet of the nitrogen storage tank and the conveying pump, wherein the control pipeline comprises a main pipeline, the inlet of the main pipeline is connected with the gas outlet of the nitrogen storage tank, and the outlet of the main pipeline is divided into two paths, one path is connected with the upper part of the conveying pump via a conveying pipeline, and the other path is connected with the lower part of the conveying pump via a pump fluidization pipeline, and a conveying control valve is arranged on the conveying pipeline, and a pump fluidization control valve is arranged on the pump fluidization pipeline.
2. The long-distance, large-capacity, closed-containment coal powder dense-phase pneumatic conveying system according to claim 1 is characterized in that: The top of the coal powder buffer hopper is connected with a material dropping pipeline and a centralized dust collecting pipeline.
3. The long-distance, large-capacity, closed-containment coal powder dense-phase pneumatic conveying system according to claim 2 is characterized in that: The outlet of the main pipeline is connected to the outlet of the outlet valve on the delivery pump via an air supply pipeline, and an air supply control valve is provided on the air supply pipeline, wherein a main valve is provided at the air outlet of the nitrogen storage tank.
4. The long-distance, large-capacity, closed-containment coal powder dense-phase pneumatic conveying system according to claim 3 is characterized in that: The main pipeline is provided with a filter and a pressure regulating valve, the filter is in front and the pressure regulating valve is in the back, the outlet of the delivery control valve on the delivery pipeline, the outlet of the pump fluidization control valve on the pump fluidization pipeline, and the outlet of the air supply control valve on the air supply pipeline are all connected with a throttling orifice plate and a check valve, the throttling orifice plate is in front and the check valve is in the back.
5. The long-distance, large-capacity, closed-containment coal powder dense-phase pneumatic conveying system according to claim 1 is characterized in that: The outlet of the hopper fluidizing pipeline is connected to the lower part of the coal powder buffer hopper through a throttling orifice pipe, and the outlet of the balance valve on the exhaust pipeline is provided with a throttling orifice plate.
6. The long-distance, large-capacity, closed-containment coal powder dense-phase pneumatic conveying system according to claim 1 is characterized in that: The pulverized coal buffer hopper is provided with a hopper level meter, and the delivery pump is provided with a pump level meter.
7. The dense phase pneumatic conveying system for long-distance, large-capacity, and closed transportation of pulverized coal as claimed in claim 1 is characterized in that: A powder return pipeline is connected between the bottom outlet of the delivery pump and the upper part of the coal powder buffer hopper, and a powder return valve is arranged on the powder return pipeline.
8. The long-distance, large-capacity, closed-containment coal powder dense-phase pneumatic conveying system according to claim 1 is characterized in that: The outlet of the delivery pump is in the shape of an arc elbow, and the inlet valve and the outlet valve are dome valves.
9. The dense phase pneumatic conveying system for long-distance, large-capacity, and closed transportation of pulverized coal as claimed in claim 1, characterized in that: The long-distance conveying pipeline is provided with a conveying elbow at its turning point, and a receiving bin is provided at the entrance of the pulverized coal storage tank. An arc-shaped baffle is provided in the receiving bin, and ceramics are affixed to the concave surface of the arc-shaped baffle. A dust collector is installed on the top of the pulverized coal storage tank, wherein the inlet end of the arc-shaped baffle corresponds to the outlet of the long-distance conveying pipeline, and the ceramics on the arc-shaped baffle face the inside of the pulverized coal storage tank, so that the mixture of nitrogen and pulverized coal transported through the long-distance conveying pipeline enters the pulverized coal storage tank along the arc-shaped baffle.
10. The coal powder dense phase pneumatic conveying system for long-distance, large-capacity, closed conveying as claimed in claim 1, characterized in that: Pressure gauges are installed on the pulverized coal buffer hopper, the delivery pump and the long-distance delivery pipeline.