An ultrasonic coal powder sampling system

Abstract

The present invention relates to the field of coal processing, and discloses an ultrasonic coal dust sampling system, including a sampling tube, an ultrasonic coal dust collector, a regulating valve, an air pump, a pressure measuring tube assembly and a pressure gauge; the ultrasonic coal dust collector includes an ultrasonic sealing belt, a baffle, a movable plate, a coal dust collection box and a shell, and the pressure measuring tube assembly includes a first pressure measuring tube and a second pressure measuring tube. The sampling tube is connected to the ultrasonic coal dust collector, the regulating valve and the air pump in sequence; the ultrasonic sealing belt is connected to the inner wall of the top of the shell, and a plurality of baffle protrusions and upper powder discharge holes are arranged on the baffle; the movable plate is located between the baffle and the coal dust collection box, and a plurality of lower powder discharge holes are arranged on the movable plate; one end of the first pressure measuring tube is located inside the sampling tube, and the first pressure measuring tube and the second pressure measuring tube are both connected to the pressure gauge; the ultrasonic sealing belt is used to generate ultrasonic waves. It can better realize the coal dust sampling work of the direct-blowing type pulverizing system under variable working conditions, and has better sampling efficiency in the direct-blowing type pulverizing system under small flow conditions.

Description

Technical Field

[0001] The invention belongs to the field of coal processing and relates to an ultrasonic coal powder sampling system. Background Art

[0002] Thermal power plants, represented by coal-fired power plants, are dominant. Generally speaking, in the process of coal combustion, the finer the coal powder entering the furnace, the more complete the combustion, and the higher the boiler combustion efficiency. However, the finer the coal powder, the higher the coal grinding cost, and it is easy to cause coal powder explosion. Therefore, the coal powder fineness needs to be kept within a reasonable range. During the operation of coal-fired power plants, it is necessary to measure and analyze the coal powder fineness in real time. According to the measurement results, the optimal range of coal powder fineness is compared, and the operating conditions of the pulverizing system are continuously adjusted to ensure that the entire coal-fired unit operates safely under efficient and stable conditions.

[0003] At present, for the intermediate storage type pulverizing system, the coal powder movable sampling tube and the coal powder free sampler are often used to sample the coal powder. For the direct blowing type pulverizing system, the constant speed sampling system is mainly used. Among them, the direct blowing type pulverizing system has the advantages of small footprint, convenient combination of coal mill, high safety during operation and low power consumption for pulverizing, but the disadvantage is that the fineness of the coal powder in the powder conveying pipe is unevenly distributed. Therefore, the movable constant speed sampling method is usually used to obtain accurate information on the fineness of the coal powder in the powder conveying pipe of the direct blowing type pulverizing system.

[0004] The isokinetic sampling system relies on air extraction to introduce the gas-powder flow in the powder conveying pipe into the sampling pipe, and collects the coal powder through gas-solid separation in a multi-stage cyclone separator. However, this isokinetic sampling system using a cyclone separator has the following problems: 1) The isokinetic sampling system using a cyclone separator has high requirements for the stability and continuity of the air extraction flow. When the flow velocity in the powder conveying pipe fluctuates greatly and the powder output flow of the powder making system changes significantly, its sampling efficiency for coal powder will be reduced; 2) The isokinetic sampling system using a cyclone separator requires a special micro-cyclone separator under a small flow of gas-powder flow, which increases the cost and complexity of the device, and the sampling effect of coal powder is not satisfactory. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide an ultrasonic coal powder sampling system.

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

[0007] An ultrasonic coal powder sampling system comprises a sampling tube, an ultrasonic coal powder collector, a regulating valve, an air pump, a pressure measuring tube assembly and a pressure gauge; the ultrasonic coal powder collector comprises an ultrasonic sealing tape, a baffle, a movable plate, a coal powder collecting box and a shell, and the pressure measuring tube assembly comprises a first pressure measuring tube and a second pressure measuring tube; one end of the sampling tube is connected to the ultrasonic coal powder collector, the regulating valve and the air pump in sequence; the shell is sleeved above the baffle, the ultrasonic sealing tape is connected to the inner wall of the top of the shell, a plurality of baffle protrusions are arranged on the baffle, and upper powder discharge holes are opened between adjacent baffle protrusions; the movable plate is located between the baffle and the coal powder collecting box, and a plurality of lower powder discharge holes are opened on the movable plate; one end of the first pressure measuring tube is located inside the sampling tube, and the first pressure measuring tube and the second pressure measuring tube are both connected to the pressure gauge; the ultrasonic sealing tape is used to generate ultrasonic waves.

[0008] Optionally, a filter is provided between the ultrasonic coal powder collector and the regulating valve.

[0009] Optionally, the distance between adjacent flow-blocking protrusions is 10 to 100 mm, and the thickness of the flow-blocking protrusions is 1 to 5 mm.

[0010] Optionally, the lengths of the upper row of powder holes and the lower row of powder holes are both not less than 90% of the length of the flow-blocking protrusion, and are both not greater than the length of the flow-blocking protrusion.

[0011] Optionally, the total length of the gap between the two side surfaces of the flow-blocking protrusion in the length direction and the inner wall surface of the shell is no more than 0.5 mm.

[0012] Optionally, the distance between adjacent upper-row powder holes is not less than 1.2 times the width of the upper-row powder holes, and the distance between adjacent lower-row powder holes is not less than 1.2 times the width of the lower-row powder holes.

[0013] Optionally, at least seven flow-blocking protrusions are provided.

[0014] Optionally, the gap between the ultrasonic sealing tape and the top of the spoiler is not greater than 5 mm.

[0015] Optionally, the ultrasonic sealing tape includes a backing, an acoustic-electric chip layer, a matching layer and an acoustic lens; one side of the acoustic lens is sequentially connected to the matching layer, the acoustic-electric chip layer, the backing and the inner wall of the top of the shell.

[0016] Optionally, the acoustic-electric chip layer is composed of a number of continuously arranged acoustic-electric chips, the ultrasonic frequency range generated by the acoustic-electric chips is 40 to 200 kHz, the backing is formed by hot pressing after mixing iron powder and epoxy resin, the matching layer material is a single layer of epoxy resin filled with alumina, and the acoustic lens material is polymethyl methacrylate.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The ultrasonic coal powder sampling system of the present invention is provided with a first pressure measuring tube, a second pressure measuring tube and a pressure gauge, and one end of the first pressure measuring tube is located inside the sampling tube, and the first pressure measuring tube and the second pressure measuring tube are both connected to the pressure gauge. The static pressure of the gas-powder flow inside and outside the sampling tube is measured by the pressure gauge through the first pressure measuring tube and the second pressure measuring tube, and the opening of the regulating valve is adjusted accordingly to balance the flow rate of the gas-powder flow inside and outside the sampling tube, thereby realizing isokinetic sampling to adapt to different flow rates in the powder conveying pipe, and better realizing the coal powder sampling work of the direct-blowing type pulverizing system under variable working conditions. The flow-blocking protrusions in the ultrasonic coal powder collector and the ultrasonic sealing belt form a plurality of independent cavities, and the powder has the effect of slowing down and stopping the airflow passing through the ultrasonic coal powder collector. At the same time, combined with the ultrasonic wave emitted by the ultrasonic sealing belt, a secondary flow with a direction different from that of the gas-powder flow can be generated in the sealing gap between the ultrasonic sealing belt and the top of the flow-blocking protrusion by relying on the acoustic flow phenomenon, thereby further dissipating the kinetic energy of the gas-powder flow and enhancing the retarding effect on the gas-powder flow, thereby causing the coal powder in the gas-powder flow to settle due to its own gravity, and achieving better sampling efficiency in the direct-blowing pulverizing system under small flow conditions.

[0019] Furthermore, a filter is arranged between the ultrasonic coal powder collector and the regulating valve to collect the coal powder remaining in the gas powder flow flowing out of the ultrasonic coal powder collector through the filter to prevent the coal powder particles from damaging the regulating valve and the air pump.

[0020] Furthermore, the distance between adjacent flow-blocking protrusions is 10 to 100 mm, and the thickness of the flow-blocking protrusions is 1 to 5 mm, thereby ensuring low material loss and low difficulty in processing and manufacturing while achieving a better sampling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the ultrasonic pulverized coal sampling system of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of the ultrasonic coal powder collector of the present invention;

[0023] Figure 3 It is a schematic diagram of the spoiler structure of the present invention;

[0024] Figure 4 It is a schematic diagram of the movable plate structure of the present invention;

[0025] Figure 5 It is a schematic diagram of the structure of the ultrasonic sealing tape of the present invention.

[0026] Among them: 1-sampling tube; 2-powder delivery pipe; 3-pipeline; 4-ultrasonic coal powder collector; 5-filter; 6-regulating valve; 7-vacuum pump; 8-pressure measuring tube assembly; 9-pressure gauge; 10-ultrasonic sealing tape; 11-baffle; 12-upper powder discharge hole; 13-movable plate; 14-lower powder discharge hole; 15-coal powder collection box; 16-housing. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0030] See also Figure 1 and 2 In one embodiment of the present invention, an ultrasonic pulverized coal sampling system is provided, comprising a sampling tube 1, an ultrasonic pulverized coal collector 4, a regulating valve 6, an air pump 7, a pressure measuring tube assembly 8 and a pressure gauge 9; the ultrasonic pulverized coal collector 4 comprises an ultrasonic sealing tape 10, a baffle 11, a movable plate 13, a pulverized coal collection box 15 and a housing 16, and the pressure measuring tube assembly 8 comprises a first pressure measuring tube and a second pressure measuring tube.

[0031] Among them, one end of the sampling tube 1 is connected to the ultrasonic coal powder collector 4, the regulating valve 6 and the vacuum pump 7 in sequence; the outer shell 16 is arranged above the baffle 11, the ultrasonic sealing belt 10 is connected to the inner wall of the top of the outer shell 16, a plurality of baffle protrusions are arranged on the baffle 11, and upper powder discharge holes 12 are opened between adjacent baffle protrusions; the movable plate 13 is located between the baffle 11 and the coal powder collection box 15, and a plurality of lower powder discharge holes 14 are opened on the movable plate 13; one end of the first pressure measuring tube is located inside the sampling tube 1, and the first pressure measuring tube and the second pressure measuring tube are both connected to the pressure gauge 9; the ultrasonic sealing belt 10 is used to generate ultrasonic waves.

[0032] Specifically, the sampling tube 1, the ultrasonic coal powder collector 4, the regulating valve 6 and the vacuum pump 7 are connected by the pipeline 3. When in use, the inlet end of the sampling tube 1 faces the incoming direction of the gas-powder flow and is placed in the powder conveying tube 2. The sampling tube 1 passes through the opening of the tube wall of the powder conveying tube 2, and the outlet end is connected to the inlet of the ultrasonic coal powder collector 4 through the pipeline 3; the first pressure measuring tube is used to measure the external static pressure of the sampling tube 1, one end of which is arranged in the flow field close to the outside of the sampling tube 1, and the other end is connected to the pressure gauge 9; the second pressure measuring tube is used to measure the internal static pressure of the sampling tube 1, one end of which is arranged inside the sampling tube 1, and the other end is also connected to the pressure gauge 9.

[0033] Specifically, the ultrasonic coal powder collector 4 is divided into a gas-powder flow static area and a coal powder collection area from top to bottom, and a movable plate 13 that can reciprocate along the flow direction of the gas-powder flow is closely arranged between the two areas; the shell 16 of the ultrasonic coal powder collector 4 remains sealed, and only the inlet and outlet for the flow of the gas-powder flow are retained. An ultrasonic sealing belt 10 is arranged on the inner wall of the top of the gas-powder flow static area, and a baffle plate 11 is arranged at the bottom. A plurality of baffle protrusions are arranged on the baffle plate 11, and upper powder discharge holes 12 are opened between adjacent baffle protrusions; the plate surface of the baffle protrusion is perpendicular to the flow direction of the gas-powder flow, and the upper powder discharge hole 12 is in the shape of a narrow strip. The inlet and outlet of the ultrasonic coal powder collector 4 are respectively arranged on the left and right of the gas-powder flow static area. The movable plate 13 can reciprocate along the flow direction of the gas-powder flow; the movable plate 13 is provided with lower powder discharge holes 14; optionally, the number, shape and arrangement of the lower powder discharge holes 14 and the upper powder discharge holes 12 are completely consistent, and the coal powder collection area is only provided with a coal powder collection box 15 that can be taken out and put back.

[0034] The ultrasonic coal powder sampling system of the present invention is provided with a first pressure measuring tube, a second pressure measuring tube and a pressure gauge 9, and one end of the first pressure measuring tube is located inside the sampling tube 1, and the first pressure measuring tube and the second pressure measuring tube are both connected to the pressure gauge 9. The pressure gauge 9 is used to measure the static pressure of the gas-powder flow inside and outside the sampling tube 1 through the first pressure measuring tube and the second pressure measuring tube, and the opening of the regulating valve 6 is adjusted accordingly to balance the flow rate of the gas-powder flow inside and outside the sampling tube 1, thereby realizing isokinetic sampling to adapt to different flow rates in the powder conveying pipe, and better realizing the coal powder sampling work of the direct-blowing type pulverizing system under variable working conditions. The flow-blocking protrusions in the ultrasonic coal powder collector 4 and the ultrasonic sealing belt 10 form a plurality of independent cavities, and the powder has the effect of slowing down and stopping the airflow passing through the ultrasonic coal powder collector 4. At the same time, combined with the ultrasonic wave emitted by the ultrasonic sealing tape 10, a secondary flow with a flow direction different from that of the gas-powder flow can be generated in the sealing gap between the ultrasonic sealing tape 10 and the top of the flow-blocking protrusion by relying on the acoustic flow phenomenon, thereby further dissipating the kinetic energy of the gas-powder flow and enhancing the retarding effect on the gas-powder flow, thereby causing the coal powder in the gas-powder flow to settle due to its own gravity, thereby achieving better sampling efficiency in the direct-blowing pulverizing system under small flow conditions.

[0035] In a possible implementation, a filter 5 is provided between the ultrasonic coal powder collector 4 and the regulating valve 6. The filter 5 collects the coal powder remaining in the gas powder flow flowing out of the ultrasonic coal powder collector 4 to prevent the coal powder particles from damaging the regulating valve 6 and the air pump 7.

[0036] See also Figure 3 In a possible implementation, the distance between adjacent flow-blocking protrusions is 10 to 100 mm, and the thickness of the flow-blocking protrusion is 1 to 5 mm. Specifically, the distance between adjacent flow-blocking protrusions is the baffle pitch a. The smaller the baffle pitch is, the better the coal powder collection effect is. However, due to the influence of the existence of the upper powder discharge holes 12 and the wind pressure of the vacuum pump 7, the baffle pitch cannot be too small. The distance between adjacent flow-blocking protrusions is set to 10 to 100 mm to obtain a better coal powder collection effect. The thickness c of the baffle protrusion is the average thickness of the upper and lower ends of the baffle protrusion. If the thickness of the baffle protrusion is too thick, it will compress the space for the slow flow of the gas powder flow and increase the consumption of materials; if the thickness of the baffle protrusion is too thin, it will increase the difficulty of processing and manufacturing. Setting the thickness of the baffle protrusion to 1 to 5 mm achieves a better balance between the two.

[0037] See also Figure 4In a possible implementation, the lengths of the upper powder discharge holes 12 and the lower powder discharge holes 14 are not less than 90% of the length of the flow-blocking protrusion, and are not greater than the length of the flow-blocking protrusion. Specifically, the lengths of the upper powder discharge holes 12 and the lower powder discharge holes 14, that is, the size d of the upper powder discharge holes 12 and the lower powder discharge holes 14 perpendicular to the flow direction of the gas-powder flow. The longer the upper powder discharge holes 12 and the lower powder discharge holes 14 are, the larger the powder discharge area is, and the smoother the powder discharge is, but the lengths of the upper powder discharge holes 12 and the lower powder discharge holes 14 cannot be longer than the length of the flow-blocking protrusion; at the same time, the upper powder discharge holes 12 and the lower powder discharge holes 14 cannot be too short, which will reduce the powder discharge area and is not conducive to the collection of coal powder. By setting the lengths of the upper powder discharge holes 12 and the lower powder discharge holes 14 to be not less than 90% of the length of the flow-blocking protrusion, and not greater than the length of the flow-blocking protrusion, the powder discharge efficiency is guaranteed to the greatest extent.

[0038] In a possible implementation, the total length of the gap between the two side surfaces of the baffle protrusion in the length direction and the inner wall surface of the shell 16 is not greater than 0.5 mm. Specifically, the length of the baffle protrusion, that is, the dimension b of the baffle protrusion perpendicular to the flow direction of the gas powder flow. The longer the baffle protrusion is, the better. It is best to be connected to the shell 16. The shortest possible length cannot make the total length of the gap between the baffle plate 11 and the inner wall surface of the ultrasonic coal powder collector 4 exceed 0.5 mm to ensure the coal powder collection effect of the ultrasonic coal powder collector 4.

[0039] In a possible implementation, the distance between adjacent upper powder discharge holes 12 is not less than 1.2 times the width of the upper powder discharge holes 12 , and the distance between adjacent lower powder discharge holes 14 is not less than 1.2 times the width of the lower powder discharge holes 14 .

[0040] In a possible implementation manner, at least seven flow-blocking protrusions are provided.

[0041] In a possible implementation manner, the gap between the ultrasonic sealing tape 10 and the top of the spoiler 11 is no greater than 5 mm.

[0042] In a possible implementation manner, the spoiler protrusion tapers in a direction away from the spoiler plate 11 .

[0043] See also Figure 5 In a possible implementation, the ultrasonic sealing tape 10 includes a backing 17, an acoustic-electric chip layer 18, a matching layer 19 and an acoustic lens 20; one side of the acoustic lens 20 is sequentially connected to the matching layer 19, the acoustic-electric chip layer 18, the backing 17 and the top inner wall of the shell 16.

[0044] Specifically, the backing 17 in the ultrasonic sealing tape 10 is closely arranged on the top inner wall of the shell 16, the outer side of the backing 17 is closely arranged on the acoustic-electric chip layer 18, the outer side of the acoustic-electric chip layer 18 is closely arranged on the matching layer 19, the outer side of the matching layer 19 is closely arranged on the acoustic lens 20, and the acoustic lens 20 is in direct contact with the gas-powder flow.

[0045] In a possible embodiment, the acoustic-electric chip layer 18 is composed of a number of continuously arranged acoustic-electric chips, which are rectangular or circular acoustic-electric chips, and the ultrasonic frequency range of the acoustic-electric chips is 40 to 200 kHz; the acoustic-electric chip layer 18 is composed of a number of continuously arranged acoustic-electric chips, and the ultrasonic frequency range of the acoustic-electric chips is 40 to 200 kHz, the backing 17 is formed by hot pressing a mixture of iron powder and epoxy resin, the matching layer 19 is made of a single layer of epoxy resin filled with alumina, and the acoustic lens 20 is made of polymethyl methacrylate.

[0046] In a possible implementation, the sampling tube 1 adopts a flat-head φ25mm elbow sampling tube, the inlet of which is directly facing the incoming direction of the gas-powder flow. When in use, it is perpendicular to the wall of the powder conveying pipe 2. The sampling tube 1 is placed in the powder conveying pipe 2 at a distance greater than 10 times the diameter of the powder conveying pipe 2 from the upstream local resistance component, and the downstream straight section of the powder conveying pipe 2 is not less than 3 times the diameter of the powder conveying pipe 2. The sampling tube 1 passes through the opening on the wall of the powder conveying pipe 2 and is connected to the ultrasonic coal powder collector 4. This section of the pipeline 3 adopts a soft rubber hose, and the remaining pipelines 3 adopt canvas hoses. Static pressure holes are respectively set on the inner and outer walls of the sampling tube 1, and a pressure measuring tube channel is reserved inside; the pressure gauge 9 adopts a micro-pressure differential sensor, and the first and second pressure measuring tubes between the sampling tube 1 and the pressure gauge 9 are both metal tubes with a diameter of φ6mm. When sampling, ensure that the static pressure difference fluctuation inside and outside the sampling tube 1 is less than 50-100Pa. The connection part between the sampling tube 1 and the opening of the powder conveying pipe 2 is fixed with a pipe seat and sealed with a sealant.

[0047] Ten flow-blocking protrusions with an average thickness of 5 mm are arranged in the ultrasonic coal powder collector 4, the spacing between adjacent flow-blocking protrusions is 20 mm, and the two ends of the flow-blocking protrusions are connected to the inner wall of the shell 16 without gaps. An upper powder discharge hole 12 is arranged between each adjacent flow-blocking protrusion, the length of the upper powder discharge hole 12 is 90% of the length of the flow-blocking protrusion, and the width of the upper powder discharge hole 12 is 7 mm. According to the arrangement of the upper powder discharge holes 12, lower powder discharge holes 14 are arranged on the movable plate 13, and the number, spacing, length and width of the lower powder discharge holes 14 are the same as those of the upper powder discharge holes 12.

[0048] The backing 17 in the ultrasonic sealing tape 10 is formed by hot pressing after fully mixing iron powder and epoxy resin. The diameter of the iron powder is 50μm and the volume fraction is 20%; the acoustic-electric chip 18 is a rectangular PZT piezoelectric ceramic piece, and the frequency is selected to be 120±10kHz. The matching layer 19 is a single layer of low-viscosity epoxy resin filled with alumina, wherein the alumina powder has a particle size of 5μm and a volume fraction of 15%, and is extruded into a thin layer by casting and filling; the acoustic lens 20 is made of polymethyl methacrylate.

[0049] Based on the above design, the ultrasonic coal powder sampling system also has good adaptability in high temperature, high humidity and high corrosive environment.

[0050] The specific working process of the ultrasonic coal powder sampling system of the present invention is as follows:

[0051] First, the static pressure of the gas-powder flow inside and outside the sampling tube 1 is measured by the pressure gauge 9 through the first and second pressure measuring tubes, and the opening of the regulating valve 6 is adjusted accordingly to balance the flow rate of the gas-powder flow inside and outside the sampling tube 1, thereby achieving isokinetic sampling. Under the action of the vacuum pump 7, the coal powder flow flows through the sampling tube 1, the ultrasonic coal powder collector 4, the filter 5, the regulating valve 6 and the vacuum pump 7 in sequence.

[0052] The gas-powder flow is sampled through the sampling tube 1, and the gas-powder flow entering the ultrasonic coal-powder collector 4 from the sampling tube 1 completes the collection function of most of the coal powder in the ultrasonic coal-powder collector 4. The flow-blocking protrusions in the ultrasonic coal-powder collector 4 and the ultrasonic sealing belt 10 form a number of independent cavities, and the powder has a slowing and stopping effect on the airflow flowing through the ultrasonic coal-powder collector 4; and the ultrasonic wave emitted by the ultrasonic sealing belt 10 can generate a secondary flow in a different direction from the gas-powder flow in the sealing gap between the ultrasonic sealing belt 10 and the top of the flow-blocking protrusion by relying on the sound flow phenomenon, further dissipating the kinetic energy of the gas-powder flow, enhancing the slowing effect on the gas-powder flow, and then causing the coal powder in the gas-powder flow to settle by its own gravity.

[0053] When the upper powder discharge hole 12 and the lower powder discharge hole 14 are completely staggered, the coal powder gathers between the adjacent flow-blocking protrusions. When the upper powder discharge hole 12 and the lower powder discharge hole 14 are completely aligned, the coal powder falls into the coal powder collecting box 15 due to gravity, thereby collecting the coal powder.

[0054] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An ultrasonic coal powder sampling system, characterized in that: It comprises a sampling tube (1), an ultrasonic coal powder collector (4), a regulating valve (6), an air pump (7), a pressure measuring tube assembly (8) and a pressure gauge (9); the ultrasonic coal powder collector (4) comprises an ultrasonic sealing belt (10), a baffle (11), a movable plate (13), a coal powder collecting box (15) and a housing (16); the pressure measuring tube assembly (8) comprises a first pressure measuring tube and a second pressure measuring tube; One end of the sampling tube (1) is connected to an ultrasonic coal powder collector (4), a regulating valve (6) and an air pump (7) in sequence; the outer shell (16) is sleeved above the baffle plate (11), the ultrasonic sealing belt (10) is connected to the inner wall of the top of the outer shell (16), a plurality of baffle protrusions are provided on the baffle plate (11), and upper powder discharge holes (12) are provided between adjacent baffle protrusions; the movable plate (13) is located between the baffle plate (11) and the coal powder collection box (15), and a plurality of lower powder discharge holes (14) are provided on the movable plate (13); one end of the first pressure measuring tube is located inside the sampling tube (1), and the first pressure measuring tube and the second pressure measuring tube are both connected to a pressure gauge (9); the ultrasonic sealing belt (10) is used to generate ultrasonic waves.

2. The ultrasonic coal powder sampling system according to claim 1, characterized in that: A filter (5) is arranged between the ultrasonic coal powder collector (4) and the regulating valve (6).

3. The ultrasonic coal powder sampling system according to claim 1, characterized in that: The distance between adjacent flow-blocking protrusions is 10-100 mm, and the thickness of the flow-blocking protrusions is 1-5 mm.

4. The ultrasonic coal powder sampling system according to claim 1, characterized in that: The lengths of the upper powder discharge hole (12) and the lower powder discharge hole (14) are both not less than 90% of the length of the flow-blocking protrusion, and are both not greater than the length of the flow-blocking protrusion.

5. The ultrasonic coal powder sampling system according to claim 1, characterized in that: The total length of the gap between the two side surfaces of the flow-blocking protrusion in the length direction and the inner wall surface of the outer shell (16) is no more than 0.5 mm.

6. The ultrasonic coal powder sampling system according to claim 1, characterized in that: The distance between adjacent upper powder discharge holes (12) is not less than 1.2 times the width of the upper powder discharge holes (12), and the distance between adjacent lower powder discharge holes (14) is not less than 1.2 times the width of the lower powder discharge holes (14).

7. The ultrasonic pulverized coal sampling system according to claim 1, characterized in that: At least seven flow-blocking protrusions are provided.

8. The ultrasonic coal powder sampling system according to claim 1, characterized in that: The gap between the ultrasonic sealing tape (10) and the top of the spoiler (11) is no greater than 5 mm.

9. The ultrasonic coal powder sampling system according to claim 1, characterized in that: The ultrasonic sealing tape (10) comprises a backing (17), an acoustic-electric chip layer (18), a matching layer (19) and an acoustic lens (20); one side of the acoustic lens (20) is sequentially connected to the matching layer (19), the acoustic-electric chip layer (18), the backing (17) and the top inner wall of the housing (16).

10. The ultrasonic coal powder sampling system according to claim 9, characterized in that: The acoustic-electric chip layer (18) is composed of a plurality of continuously arranged acoustic-electric chips, the ultrasonic frequency range of which is 40 to 200 kHz. The backing (17) is formed by hot pressing after mixing iron powder and epoxy resin. The matching layer (19) is made of a single layer of epoxy resin filled with alumina. The acoustic lens (20) is made of polymethyl methacrylate.

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