Superfine pulverized coal blanking system and method

Abstract

The invention discloses a superfine pulverized coal discharging system and method.The system comprises a pulverized coal bin, a pulverized coal feeding device and a pulverized coal discharging device, the pulverized coal bin comprises a straight-barrel-shaped upper body and a conical-barrel-shaped lower body, a flow guide folded plate and a pulverized coal discharging port are arranged in the conical-barrel-shaped lower body, the flow guide folded plate is provided with a downwards-inclined surface, and an annular discharging gap is reserved between the periphery of the flow guide folded plate and the inner wall of the pulverized coal bin; the inclined discharging pipe is positioned on one side of the conical cylindrical lower body of the pulverized coal bunker; the gas purging pipeline is communicated with the interior of the discharging pipe and is used for introducing gas into the discharging pipe; the pulverized coal conveying device is communicated with the pulverized coal outlet of the blanking pipe and is used for conveying pulverized coal to the downstream; and the circulating anti-blocking pipeline is located between the top of the pulverized coal bunker and the tail of the pulverized coal conveying device, and the tail area of the pulverized coal conveying device is communicated with the micro-negative pressure environment in the pulverized coal bunker through the circulating anti-blocking pipeline. The invention can solve the problem that the raw material of the pulverized coal silo of the direct coal liquefaction device is blocked and difficult to discharge due to caking and bridging, and ensures that the raw material pulverized coal is continuously and stably discharged.

Description

Technical Field

[0001] The invention belongs to the field of coal chemical industry and direct coal liquefaction, and in particular relates to a superfine coal powder feeding system method. Background Art

[0002] Coal direct liquefaction is a process in which raw coal is made into coal powder with a particle size of less than 74 microns, 5% ash content, and 4% water content, and mixed with supplementary sulfur, catalyst and solvent in proportion to prepare oil-coal slurry, and reacts under high temperature, high pressure, hydrogen and catalyst to generate liquefied oil. Coal powder for direct liquefaction has a particle size of less than 74 microns and contains a small amount of water. Therefore, it is very easy to form bridges and agglomerates during transportation, blocking the conveying rotary discharge valve, resulting in interruption of coal supply to the coal direct liquefaction device, which seriously affects the operating load and production efficiency of the device.

[0003] In the prior art, methods such as drying to reduce moisture content, vibration loosening and screw conveying are generally used to solve the blockage problem, but there are still some defects. For example, the factors affecting drying include: 1. The nature of the material determines the moisture content limit after drying; 2. The drying technical means determine the moisture content limit after drying; 3. The equipment operating temperature limit determines the drying moisture content limit. Factors affecting vibration include: 1. The technical design of related equipment has limitations; 2. The frequency and amplitude of vibration have upper limits; 3. The pulverized coal silo and frame support have strict requirements on vibration conditions. Factors affecting screw conveying include: 1. When the upstream is blocked, the screw basically does not play a role in clearing; 2. When the amount of material discharged is too large, the screw may shut down due to overcurrent overload; 3. When the screw is blocked, it can only be shut down for disposal, affecting normal material discharge production. Summary of the invention

[0004] In order to solve the above-mentioned defects in the prior art, the present invention provides an ultra-fine coal powder feeding system and method, which can solve the problems such as the difficulty in feeding coal powder due to the bridging of raw materials in the pulverized coal silo of the coal direct liquefaction device, thereby ensuring the continuous and stable feeding of raw coal powder and avoiding the above-mentioned problems affecting the operating load and production efficiency of the coal liquefaction device.

[0005] In order to achieve the above-mentioned object of the invention, the first aspect of the present invention provides an ultra-fine coal powder feeding system, comprising:

[0006] A pulverized coal bin, which has a cavity inside for storing and discharging pulverized coal, comprises a straight cylindrical upper body and a conical cylindrical lower body connected to the upper body, a guide fold plate and a pulverized coal discharging port below the guide fold plate are arranged on the path of pulverized coal falling inside the conical cylindrical lower body, the guide fold plate has a downwardly inclined surface, and an annular discharging gap is left around the guide fold plate and the inner wall of the pulverized coal bin;

[0007] At least one inclined feed pipe is located on one side of the conical cylindrical lower body of the coal powder bin, and the coal powder inlet of the feed pipe is connected to the coal powder feed port;

[0008] A gas purge pipeline is connected to the interior of the feed pipe and is used to introduce gas into the interior of the feed pipe;

[0009] A pulverized coal conveying device, connected to the pulverized coal outlet of the feed pipe, for conveying the pulverized coal to the downstream;

[0010] The circulating anti-blocking pipeline is located between the top of the coal powder bin and the tail of the coal powder conveying device. The tail area of ​​the coal powder conveying device is connected to the slightly negative pressure environment inside the coal powder bin through the circulating anti-blocking pipeline.

[0011] Furthermore, the guide baffle is selected from one of an inverted V-shape, a fan-shape, a trapezoid and a cone, and has at least two surfaces inclined downward.

[0012] Furthermore, a guide fold plate is added at a position 1.1-1.3m above the pulverized coal discharge port, and a 0.15-0.25m annular discharge gap is left around the guide fold plate and the inner wall of the pulverized coal bin.

[0013] Furthermore, a control valve I for controlling the coal powder discharge flow rate is arranged on the pipeline of the discharge pipe.

[0014] Furthermore, a control valve II for switching the coal powder discharge on or off is provided at the bottom of the discharge pipe.

[0015] Furthermore, a control valve III for controlling the flow of air in the circulation anti-blocking pipeline is provided in the middle section of the circulation anti-blocking pipeline.

[0016] Furthermore, a control valve IV is provided on the gas purge pipeline to achieve communication between the gas purge pipeline and the feed pipe. Preferably, the gas purge pipeline is connected above the control valve I and between the control valve II.

[0017] Furthermore, the system comprises a first discharge pipe and a second discharge pipe located between the coal powder discharge port of the coal powder bin and the coal powder conveying device.

[0018] Furthermore, the particle size of the ultrafine coal powder is 5 μm-210 μm.

[0019] The second aspect of the present invention provides a method for feeding ultrafine coal powder, using the ultrafine coal powder feeding system, comprising the following steps:

[0020] S1: Start the pulverized coal conveying device and open the circulation anti-blocking pipeline control valve III;

[0021] S2: The pulverized coal bin starts to discharge, causing the control valve I to gradually open from 0% to 100% fully open, and the control valve II is fully open, and the pulverized coal falls into the discharge pipe;

[0022] S3: When material discharge is not smooth, open the gas purge pipeline control valve IV to purge gas into the lower material pipe.

[0023] Furthermore, the method further includes step S4: the material discharge pipe includes a first material discharge pipe and a second material discharge pipe, and when the material discharge from the first material discharge pipe is not smooth, the material discharge is switched to the second material discharge pipe.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] The present invention takes into account the problem that the coal powder in direct liquefaction has a small particle size and a small amount of water, which is easy to agglomerate and form bridges to block the discharge pipe under the deadweight pressure of the material level. First, the coal powder silo is modified, and a guide fold plate with a downward inclined surface is added above the discharge port. An annular discharge gap is left between the guide fold plate and the silo wall. The selection of the guide fold plate position is optimized, and the properties of the raw material pulverized coal of the coal liquefaction device are fully considered. This not only solves the problem of poor discharge blockage in the pulverized coal silo, but also meets the discharge volume requirement of the device; secondly, the present invention leads out an inclined discharge pipe from the conical cylindrical lower body of the coal powder silo below the guide fold plate to ensure The invention ensures that the coal powder can maintain a certain flow rate during the feeding process, so as to avoid the interruption of feeding due to the formation of agglomeration bridges in the feeding pipe or the feeding end caused by insufficient flow rate; and the present invention introduces a gas purge pipeline in the feeding pipe, for example, in the middle section. When blockage occurs, the feeding line can be dredged by gas purge, and the feeding is restored in time to ensure the unobstructed feeding line; at the same time, the present invention designs a circulating anti-blocking line, which is located between the top of the coal powder bin and the tail of the coal powder conveying device, and the steam and dust generated are connected to the circulating anti-blocking line by the micro-negative pressure of the coal powder bin to eliminate gas blockage, so as to ensure efficient and stable transportation of the coal powder bin of the coal liquefaction device.

[0026] Other features and advantages of the present invention will be described in detail through the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of an ultrafine coal powder feeding system provided in an embodiment of the present invention.

[0028] Figure 2 A schematic structural diagram of a fan-shaped guide baffle provided in an embodiment of the present invention.

[0029] Figure 3 A schematic structural diagram of a multi-faceted triangular guide fold provided in an embodiment of the present invention.

[0030] Figure 4 A schematic structural diagram of a trapezoidal guide baffle provided in an embodiment of the present invention.

[0031] The markings are as follows: 101- pulverized coal silo; 102- flow guide flap inside the silo; 103- gate valve at the bottom of the silo; 104- rotary unloading valve; 105- screw conveyor; 106- circulation anti-blocking line; 107- circulation anti-blocking line manual valve; 108- A-line discharge pipe; 109- B-line discharge pipe; 110- A-line pneumatic control valve; 111- A-line nitrogen purge; 112- B-line pneumatic control valve; 113- B-line nitrogen purge; 114- B-line root ball valve; 115- A-line root ball valve, 116- discharge port. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the concept of the present application and the technical effects produced in combination with the embodiments, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present application.

[0033] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0034] In the prior art, the structure of the coal powder silo generally adopts a cylindrical body structure. The coal powder is directly fed to the screw feeder by its own weight through the discharge gate valve and the rotary discharge valve inside the silo. Due to the small particle size of the coal powder, the water content and the large conveying volume, the bridge of the cone section of the coal powder silo is often blocked, and the discharge port and the back pipeline are empty, which affects the operating load and production efficiency of the coal liquefaction device. In order to solve the above problems, Figure 1 As shown, the present invention particularly provides an ultra-fine coal powder feeding system, comprising:

[0035] A pulverized coal bin, which has a cavity inside for storing and discharging pulverized coal, comprises a straight cylindrical upper body and a conical cylindrical lower body connected to the upper body, a guide fold plate and a pulverized coal discharging port below the guide fold plate are arranged on the path of pulverized coal falling inside the conical cylindrical lower body, the guide fold plate has a downwardly inclined surface, and an annular discharging gap is left around the guide fold plate and the inner wall of the pulverized coal bin;

[0036] At least one inclined feed pipe is located on one side of the conical cylindrical lower body of the coal powder bin, and the coal powder inlet of the feed pipe is connected to the coal powder feed port;

[0037] A gas purge pipeline is connected to the interior of the feed pipe and is used to introduce gas into the interior of the feed pipe;

[0038] A pulverized coal conveying device, connected to the pulverized coal outlet of the feed pipe, for conveying the pulverized coal to the downstream;

[0039] The circulating anti-blocking pipeline is located between the top of the coal powder bin and the tail of the coal powder conveying device. The tail area of ​​the coal powder conveying device is connected to the slightly negative pressure environment inside the coal powder bin through the circulating anti-blocking pipeline.

[0040] In some embodiments, the guide fold is in an inverted V shape, fan shape, trapezoidal shape, cone shape, etc. The guide fold has a downward inclined surface, and the coal powder falling on the surface can play a buffering role, greatly reducing the impact of the coal powder on the equipment at the bottom of the silo. At the same time, the side wall surface of the coal powder bin below the guide fold can provide re-acceleration for the buffered coal powder, so that the coal powder can quickly pass through the annular feeding gap to ensure the coal powder feeding efficiency. In addition, the guide fold can protect the feeding port to prevent a large amount of coal powder from directly impacting the feeding pipe entrance, thereby causing the feeding port to be blocked.

[0041] In the present invention, the fixing method of the guide flap in the pulverized coal bin refers to the conventional method in the art, for example, the guide flap is fixed to the inner wall of the pulverized coal bin by welding or bolts.

[0042] In some embodiments, the inverted V angle of the inverted V-shaped guide fold is 140-150°, exemplarily 140°, 142°, 144°, 146°, 148°, 150°, etc.

[0043] In some embodiments, the diameter of the discharge port at the bottom of the coal powder bin is 0.35-0.55m, exemplarily 0.35m, 0.4m, 0.45m, 0.5m, 0.55m, etc., and the angle between the bottom end of the side wall of the conical cylindrical lower body and the horizontal is 120-130°. Preferably, a guide folding plate is added at a position 1.1-1.3m above the coal powder discharge port, exemplarily 1.1m, 1.15m, 1.2m, 1.25m, 1.3m, etc., and a 0.15-0.25m annular discharge gap is left between the guide folding plate and the bin wall, exemplarily 0.15m, 0.16m, 0.17m, 0.18m, 0.19m, 0.20m, 0.21m, 0.22m, 0.23m, 0.24m, 0.25m, etc. The selection and optimization of this position fully considers the properties of the raw material pulverized coal of the coal liquefaction unit, which not only solves the problem of blockage in the pulverized coal silo, but also meets the discharge volume requirements of the unit.

[0044] In some embodiments, a control valve I for adjusting the coal powder discharge flow rate is provided on the pipeline of the discharge pipe, preferably in the middle section of the discharge pipe, and the coal powder flow rate is controlled by the valve opening, and the coal powder bin weight can be controlled at the same time, so as to achieve remote, stable, quantitative and convenient operation. It is ensured that the coal powder can maintain a certain flow rate during the discharge process, and the formation of agglomeration bridges in the discharge pipe or at the discharge end due to insufficient or excessive flow rate is avoided, resulting in interruption of discharge.

[0045] In some embodiments, a control valve II for switching the coal powder discharge on or off is provided at the bottom of the discharge pipe.

[0046] In some embodiments, the system includes a first feed pipe and a second feed pipe located between the coal powder feeding port of the coal powder bin and the coal powder conveying device, for example Figure 1 The A-way feeding pipe and the B-way feeding pipe in the first feeding pipe and the second feeding pipe are both provided with the control valve I and the control valve II. The setting of the double feeding pipeline also greatly reduces the possibility of material interruption during feeding.

[0047] In some embodiments, in order to effectively prevent the generation of a large amount of steam and dust during the unloading process due to the high temperature and high water content of the coal powder, forming air blockage, the present invention sets a circulating anti-blockage line between the top of the coal powder bin and the tail of the coal powder conveying device. The purpose of selecting the top of the coal powder bin and the tail of the coal powder conveying device as the connection point is to ensure that the anti-blockage line can be continuously unblocked. If the upper part of the side wall of the coal powder bin is selected, condensed water and dust mixed deposition may block the end of the anti-blockage line. If the lower part is selected, the anti-blockage line will be directly blocked due to the position requirements of the powder bin, thereby causing the anti-blockage line to fail; if the front end of the coal powder conveying device is selected, the air blockage in the middle and the end may still exist, and the gas cannot be discharged. The present invention selects the steam and dust generated at the end of the conveying device to be effectively connected to the circulating anti-blockage line by the micro-negative pressure of the coal powder silo to eliminate the air blockage, so as to ensure the efficient and stable transportation of the coal powder silo of the coal liquefaction device, and set a control valve III in the middle section of the circulating anti-blockage pipeline to control the air flow in the pipeline.

[0048] In some embodiments, a gas purge pipeline is connected above the control valve I and between the control valve II. A control valve IV is arranged on the gas purge pipeline to achieve communication between the gas purge pipeline and the feed pipe. When a blockage occurs, the feed pipe can be dredged by nitrogen purge, and the feed is promptly resumed to ensure that the feed pipe is unblocked, thus achieving efficient online cleaning and dredging of the feed pipe blockage.

[0049] In the present invention, the particle size of the ultrafine coal powder is 5 μm-210 μm.

[0050] In the present invention, the control valve I, control valve II, control valve III and control valve IV mentioned above are conventional valves in the art, such as pneumatic valves, ball valves, etc., and the specific structural form is not limited.

[0051] Using the above-mentioned ultra-fine coal powder feeding system, the second aspect of the present invention provides an ultra-fine coal powder feeding method, comprising the following steps:

[0052] S1: Start the pulverized coal conveying device and open the circulation anti-blocking pipeline control valve III;

[0053] S2: The pulverized coal bin starts to discharge, causing the control valve I to gradually open from 0% to 100% fully open, and the control valve II is fully open, and the pulverized coal falls into the discharge pipe;

[0054] S3: When the material discharge from the discharge pipe is blocked, open the gas purge line control valve IV to purge gas into the lower discharge pipe.

[0055] In some embodiments, in step S3, whether the material discharge from the feed pipe is blocked is determined based on the temperature of the feed pipe, the current of the pulverized coal conveyor, and changes in the display value of the downstream mass flow meter.

[0056] In some embodiments, step S4 is further included: the feed pipe includes a first feed pipe and a second feed pipe, and when the first feed pipe is blocked from feeding, the feed pipe is switched to the second feed pipe for feeding.

[0057] The following examples are used to further illustrate the ultrafine coal powder feeding system and method of the present invention, but the present invention is not limited thereto.

[0058] Example 1

[0059] In this embodiment, the structure of the raw coal powder bin is changed, and the unloading gate valve 103 at the bottom is used in the raw coal powder bin to start unloading when the operation is started or stop unloading when the operation is stopped for maintenance. In this embodiment, it is closed and is only used to discharge the remaining material when the device is shut down for maintenance; the rotary unloading valve 104 is used in the raw coal powder bin to control the unloading of silo coal powder. When it is applied to the coal liquefaction device, the conveying effect of ultrafine coal powder is not ideal. In this embodiment, it is in a long-term unused state.

[0060] The ultra-fine coal powder feeding system provided in the embodiment of the present invention comprises: a coal liquefaction raw material coal powder silo 101, which is used for storing raw materials of the coal liquefaction device; a silo cone section guide folding plate 102 (structured as Figure 2As shown), it is used to prevent coal powder from accumulating and blocking the discharge port, ensure the annular distribution of the discharge, and provide power for the discharge; the screw conveyor 105 is used to transport the coal powder discharged from the silo to the downstream device; the circulating anti-blocking line 106 effectively reduces the air resistance generated during the coal powder transportation process to ensure the smooth discharge of the coal powder; the A and B channel discharge pipes 108 and 109 are used for the discharge designed by the present invention, replacing the original discharge process; the A and B channel pneumatic control valves I (110 and 112) are used for the design of the present invention to control the coal powder flow rate; the A and B channel purge nitrogen purge pipelines 111 and 113 are used to clear the blockage with purge nitrogen when the discharge is not smooth; the A and B channel root ball valves II (114 and 115) are used to start and stop the coal powder discharge. The above-mentioned devices, equipment and pipelines are all equipped with nitrogen for heating and purge replacement, and the coal powder silo is equipped with air hammer nitrogen and loosening nitrogen, which will not be described in detail here.

[0061] In Example 1, the diameter of the discharge port at the bottom of the coal powder bin is 0.4m, the bottom end of the conical cylindrical lower body side wall is at an angle of 128° to the horizontal, the guide fold plate 102 is set 1.2m above the coal powder discharge port, and a 0.2m annular discharge gap is left between the guide fold plate and the bin wall.

[0062] The embodiment of the present invention provides a method for feeding ultrafine coal powder, and the detailed implementation steps are as follows:

[0063] S1) The device is started to prepare for unloading, the downstream rotating equipment and screw conveyor 105 are started, the circulation anti-blocking line valve 107 is opened, the coal powder bin position is controlled to 50%, the pneumatic control valve I (110, 112) is adjusted to be flexible and accurately positioned, and the coal powder silo nitrogen system is put into use normally.

[0064] S2) starts unloading, slightly opens the pneumatic control valves I (110, 112) by 5% each, and slowly fully opens the root ball valves II (114, 115) in sequence, and observes whether the unloading is normal. The unloading amount is adjusted by the opening size of the pneumatic control valve I until the unloading requirement is met, and one of the routes is operated, and the other route is kept in reserve.

[0065] S3) When it is found that the material discharge is not smooth, first check whether the pneumatic control valve I is operating normally, repeatedly open and close the pneumatic control valve I to observe the material discharge situation; if it is still not smooth, use nitrogen to purge and dredge, and observe the material discharge situation; if it is still not smooth, switch to another route to operate, and take this route offline for processing.

[0066] The implementation of this embodiment is as follows: after the design and implementation of the transformation of the present invention, the coal powder unloading operation of the coal liquefaction device is stable, and there has never been a situation in which the load of the device is reduced due to problems such as blockage, interruption of unloading of the coal powder bin, and failure of the rotary conveying equipment, thereby meeting the raw material supply for high-load operation of the coal liquefaction device; the labor for clearing blockages is greatly reduced; at the same time, the coal powder unloading efficiency of the coal liquefaction device is improved, which plays a decisive role in ensuring the raw material supply of the coal liquefaction device; the deactivation of the rotary unloading valve directly saves 19.5kw / h of electricity consumption and saves 34,800 yuan in the operating cycle.

[0067] The implementation of the transformation designed by the present invention completely solves various problems existing in the operation of the original design scheme, provides raw material supply guarantee for the efficient operation of the coal liquefaction device, and makes a positive response to cost reduction and efficiency improvement of the coal liquefaction device.

[0068] Example 2

[0069] In this embodiment, the structure of the raw coal powder bin is changed, and the unloading gate valve 103 at the bottom is used in the raw coal powder bin to start unloading when the operation is started or stop unloading when the operation is stopped for maintenance. In this embodiment, it is closed and is only used to discharge the remaining material when the device is shut down for maintenance; the rotary unloading valve 104 is used in the raw coal powder bin to control the unloading of silo coal powder. When it is applied to the coal liquefaction device, the conveying effect of ultrafine coal powder is not ideal. In this embodiment, it is in a long-term unused state.

[0070] The ultra-fine coal powder feeding system provided in the embodiment of the present invention comprises: a coal liquefaction raw material coal powder silo 101, which is used for storing raw materials of the coal liquefaction device; a silo cone section guide folding plate (multi-faceted triangle, such as Figure 3 As shown) 102, used to prevent coal powder accumulation from blocking the discharge port, ensure the annular distribution of the discharge, and provide power for the discharge; the screw conveyor 105 is used to transport the coal powder discharged from the silo to the downstream device; the circulation anti-blocking line 106 effectively reduces the air resistance generated during the coal powder transportation process to ensure the smooth discharge of the coal powder; the A and B channel discharge pipes 108, 109 are used for the discharge designed by the present invention to replace the original discharge process; the A and B channel pneumatic control valves I (110, 112) are used for the design of the present invention to control the coal powder flow rate; the A and B channel purge nitrogen purge pipelines 111, 113 are used to clear the blockage with purge nitrogen when the discharge is not smooth; the A and B channel root ball valves II (114, 115) are used to start and stop the coal powder discharge. The above-mentioned devices, equipment and pipelines are all equipped with nitrogen for heating and purge replacement. The coal powder silo is equipped with air hammer nitrogen and loosening nitrogen, which will not be described in detail here.

[0071] The ultrafine coal powder feeding method of the embodiment of the present invention has the same detailed implementation steps as embodiment 1.

[0072] The difference between this example and Example 1 is that the form of the guide fold plate of the silo cone section is changed from a fan shape to a multi-faceted triangle.

[0073] The implementation is as follows: After the transformation, combined with the actual operation of the coal liquefaction unit, it can be seen that this form of guide folding plate can still meet the material discharge needs of production operation. Due to the different forms of guide folding plates, uneven annular spacing, and side supports, coal powder accumulation will occur to a certain extent, which may affect the coal powder discharge amount over time.

[0074] Example 3

[0075] The ultrafine coal powder feeding method and system provided in this example are similar to those of Example 1, except that the position of the guide fold plate is changed. In Example 1, a guide fold plate is added at a position 1.2m above the coal powder feeding port, and a 0.2m annular feeding gap is left between the guide fold plate and the silo wall. In Example 3, a guide fold plate is added at a position 1.1m above the coal powder feeding port, and a 0.134m annular feeding gap is left between the guide fold plate and the silo wall.

[0076] The implementation status is as follows: After the implementation of this transformation, combined with the actual unloading operation of the coal liquefaction unit, it can be seen that: 1. Due to the reduction in height, the distance of the annular gap becomes smaller, resulting in a smaller unloading amount; 2. While ensuring that the annular spacing remains unchanged, due to the reduction in height, the pulverized coal annular gap unloading distance is closer to the entrance of the unloading pipe, the pulverized coal flow rate will be reduced, and for a long time it may cause pulverized coal to accumulate and affect unloading.

[0077] Example 4

[0078] The ultrafine coal powder feeding method and system provided in this example are similar to those in Example 1, except that: Example 1 adds a guide fold plate 1.2m above the coal powder feeding port, and Example 4 adds a guide fold plate 1.3m above the coal powder feeding port, leaving a 0.265m annular feeding gap between the guide fold plate and the silo wall.

[0079] The implementation situation is as follows: After the transformation was implemented, combined with the actual unloading operation of the coal liquefaction unit, it can be seen that: 1. Due to the increase in height, the distance of the annular gap becomes larger, resulting in an increase in the unloading amount; 2. While ensuring that the annular spacing remains unchanged, due to the increase in height, the pulverized coal annular gap unloading is far away from the entrance of the unloading pipe, the cone section space becomes larger, the pulverized coal flow rate will increase, and for a long time it may cause gas accumulation in the cone section space, increase the gas resistance, and thus affect the pulverized coal unloading.

[0080] Comparative Example 1

[0081] In this comparative example, the structure of the raw coal powder bin is changed, and the unloading gate valve 103 at the bottom is used in the raw coal powder bin to start unloading when the operation is started or stop unloading when the operation is stopped for maintenance. In this comparative example, it is closed and is only used to discharge the remaining material when the device is shut down for maintenance. The rotary unloading valve 104 is used in the raw coal powder bin to control the unloading of silo coal powder. The conveying effect of ultrafine coal powder in the coal liquefaction device is not ideal, and it is in a long-term unused state in this comparative example.

[0082] The ultrafine coal powder feeding system provided in comparative example 1 includes: coal liquefaction raw material coal powder silo 101, which is used for raw material storage of coal liquefaction device; silo cone section guide folding plate 102, which is used to prevent coal powder from accumulating and blocking the feeding port, ensure the annular distribution of feeding, and provide power for feeding; screw conveyor 105, which is used to transport coal powder fed from silo to downstream device; circulation anti-blocking line 106, which effectively reduces the air resistance generated during coal powder transportation and ensures the smooth feeding of coal powder; A and B feeding pipes 108 and 109, which are used for feeding designed by the present invention, replacing the original feeding process; A and B pneumatic control valves I (110 and 112), which are used for controlling coal powder flow designed by the present invention; A and B root ball valves II (114 and 115), which are used for opening and stopping coal powder feeding. The above-mentioned devices, equipment and pipelines are all provided with nitrogen for heating and purging and replacement, and air hammer nitrogen and loosening nitrogen are provided in the coal powder silo, which will not be described in detail here.

[0083] The difference from Example 1 is that: the A and B path nitrogen purge pipelines 111 and 113 are missing, which are used to clear blockages with nitrogen purge when material unloading is not smooth; the implementation situation is as follows: It can be seen from the actual unloading operation of the coal liquefaction device that when the unloading pipe is blocked, it can only be processed offline, and online gas unblocking cannot be achieved, which increases the labor workload and prolongs the processing time, resulting in a decrease in the unloading system's ability to resist fluctuations, thereby affecting the high-load operation of the coal liquefaction device.

[0084] Comparative Example 2

[0085] The difference from Example 1 is that: the circulation anti-blocking line 106 is missing; the implementation is as follows: It can be seen from the actual unloading operation of the coal liquefaction device that unsmooth unloading often occurs in actual operation. When unloading is blocked or unsmooth, nitrogen can be purged through the A and B lines to clear the blockage. Combined with the actual situation, the main reason for the unsmooth unloading is the gas blockage between the end of the unloading pipe and the tail of the screw conveyor. Since the gas cannot be removed in time, the frequency of unsmooth unloading and blockage increases, consuming a lot of unblocking nitrogen and manpower and material resources. It also leads to a decrease in the anti-fluctuation ability of the unloading system, affecting the high-load operation of the coal liquefaction device.

[0086] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as limiting the present invention. Those skilled in the art will appreciate that, under the guidance of this specification, some modifications or adjustments may be made to the present invention. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. An ultra-fine coal powder feeding system, characterized in that: include: A pulverized coal bin, which has a cavity inside for storing and discharging pulverized coal, comprises a straight cylindrical upper body and a conical cylindrical lower body connected to the upper body, a guide fold plate and a pulverized coal discharging port below the guide fold plate are arranged on the path of pulverized coal falling inside the conical cylindrical lower body, the guide fold plate has a downwardly inclined surface, and an annular discharging gap is left around the guide fold plate and the inner wall of the pulverized coal bin; At least one inclined feed pipe is located on one side of the conical cylindrical lower body of the coal powder bin, and the coal powder inlet of the feed pipe is connected to the coal powder feed port of the coal powder bin; A gas purge pipeline is connected to the interior of the feed pipe and is used to introduce gas into the interior of the feed pipe; A pulverized coal conveying device, connected to the pulverized coal outlet of the feed pipe, for conveying the pulverized coal to the downstream; The circulating anti-blocking pipeline is located between the top of the coal powder bin and the tail of the coal powder conveying device. The tail area of ​​the coal powder conveying device is connected to the slightly negative pressure environment inside the coal powder bin through the circulating anti-blocking pipeline.

2. The ultra-fine coal powder feeding system according to claim 1, characterized in that: The shape of the guide fold plate is selected from one of an inverted V shape, a fan shape, a trapezoidal shape and a cone shape, and the guide fold plate has at least two surfaces inclined downward.

3. The ultra-fine coal powder feeding system according to claim 1 or 2, characterized in that: A guide fold plate is added 1.1-1.3m above the coal powder discharge port, and a 0.15-0.25m annular discharge gap is left between the guide fold plate and the inner wall of the coal powder bin.

4. The ultra-fine coal powder feeding system according to claim 1, characterized in that: A control valve I for controlling the flow rate of coal powder discharge is arranged on the pipeline of the discharge pipe; and / or, A control valve II for switching the coal powder discharge on or off is arranged at the bottom of the discharge pipe.

5. The ultra-fine coal powder feeding system according to claim 1, characterized in that: The middle section of the circulation anti-blocking pipeline is provided with a control valve III for controlling the flow of air in the pipeline.

6. The ultra-fine coal powder feeding system according to claim 1 or 4, characterized in that: A control valve IV is arranged on the gas purge pipeline to achieve communication between the gas purge pipeline and the discharge pipe. Preferably, the gas purge pipeline is connected above the control valve I and between the control valve II.

7. The ultra-fine coal powder feeding system according to any one of claims 1 to 6, characterized in that: The system comprises a first discharge pipe and a second discharge pipe located between a coal powder discharge port of a coal powder bin and a coal powder conveying device.

8. The ultra-fine coal powder feeding system according to any one of claims 1 to 7, characterized in that: The particle size of the ultrafine coal powder is 5 μm-210 μm.

9. A method for discharging ultrafine coal powder, using the ultrafine coal powder discharging system according to any one of claims 1 to 8, characterized in that: The steps include: S1: Start the pulverized coal conveying device and open the circulation anti-blocking pipeline control valve III; S2: The pulverized coal bin starts to discharge, causing the control valve I to gradually open from 0% to 100% fully open, and the control valve II is fully open, and the pulverized coal falls into the discharge pipe; S3: When material discharge is not smooth, open the gas purge pipeline control valve IV to purge gas into the lower material pipe.

10. The method for feeding ultrafine coal powder according to claim 9, characterized in that: The step S4 is also included: the material discharge pipe includes a first material discharge pipe and a second material discharge pipe, and when the material discharge from the first material discharge pipe is not smooth, the material is switched to the second material discharge pipe for discharge.

Images