A dry powder adsorbent mixing and distribution test device and method

Abstract

The present invention relates to a dry powder adsorbent homogeneous mixing and distribution test device and method. The device includes a dry powder feeding unit, a compressed air supply unit, a dry powder injector, a dry powder homogeneous mixer and distributor, a dust collector, and a fan. An air-powder branch pipe is provided at the outlet of the dry powder homogeneous mixer and distributor; the dust collector includes filter bags, and the air-powder branch pipe is communicated with the filter bags. The method includes adjusting the rotation speed of the dry powder feeding unit, calibrating the rotation speed - powder feeding amount relationship, emptying the filter bags, recording the weight of the filter bags, adjusting the rotation speed of the fan to make the air speed of the dry powder homogeneous mixer and distributor reach the designed value, starting the compressed air supply unit to make the adsorbent feeding amount reach the designed value for testing. After the test, record the weight of the filter bags, and statistically analyze the distribution uniformity of the adsorbent based on the weight of the filter bags before and after the test and the weight of the adsorbent in the air-powder branch pipe. The present invention provides a test basis for the optimized design and engineering popularization and application of the base dry powder adsorbent injection and removal of SO3 technology device, and has a simple structure, is convenient to use, and has high safety.

Description

Technical Field

[0001] The invention relates to a dry powder adsorbent homogeneous mixing and distribution test device and method. Background Art

[0002] After the ultra-low emission transformation of coal-fired power plants, tail facilities such as low-temperature economizers, wet desulfurization, and wet electrostatic precipitators can remove most of the SO in flue gas. 3 , but it does not help to solve SO 3 The resulting problems include limited peak load depth of the unit, severe blockage of ammonium bisulfate in the air preheater and low-temperature economizer, etc. Alkaline dry powder adsorbent is installed at the inlet of the SCR denitrification device to spray and remove SO 3 The system helps to solve the above problems.

[0003] The alkaline dry powder adsorbent injection system for removing SO3 belongs to the dry desulfurization technology. The removal efficiency is directly related to the mixing effect of flue gas and adsorbent. Different from the furnace calcium injection desulfurization technology, the flue gas flow field at the inlet of the SCR denitrification device is much smoother and more uniform than that in the furnace. It is very difficult to evenly mix the flue gas and adsorbent, and special dry powder injection technology and equipment must be developed.

[0004] See Chinese patent publication number CN205165028U for a method for removing SO 3 The dry powder atomization injection device includes a dry powder storage system, a dry powder conveying system, and a dry powder injection system. The dry powder conveying system is connected to the injection system. The high wind pressure provided by the fan to the injector blows the alkali dry powder in the silo into the distributor, and then enters the flue after being dispersed by the distributor and mixes with SO 3 Reaction. The removal of SO 3 The dry powder atomization injection device pays attention to the requirement of this technology for the uniformity of dry powder adsorption dosage at the inlet of each injector. The design idea is to use high-pressure wind to blow the alkali dry powder in the silo into the distributor, and then disperse it through the distributor and evenly enter the flue, but the performance indicators of the distributor were not tested through physical model tests.

[0005] See the Chinese patent with publication number CN209596867U, which discloses a dry powder adsorbent spray gun, which includes a spray gun body, a primary discrete baffle, a secondary discrete baffle and a terminal baffle. The dry powder adsorbent enters the spray gun inlet in the form of gas-solid two-phase flow through a high-pressure gas source, passes through the spray gun body and enters the half-pipe part. The high-speed advancing dry powder collides with the discrete baffle and disperses to the surroundings. This patent mainly focuses on the dispersion of the adsorbent at the outlet of the dry powder adsorbent spray gun, and does not involve the difference in the amount of dry powder adsorbent at the inlet of each spray gun.

[0006] Chinese Patent Publication No. CN110314502A discloses a charged dry desulfurizer injection system, which includes a chassis, a feedback blower, a dry powder feeder, a pneumatic conveying connecting hose, a dry powder feeding pipe, a flow control valve, a reducing tee connection, a high-voltage power generator, a flexible joint, a spray gun body, and a high-voltage core cable. The outlet end of the spray gun body is connected to the flue gas duct. By supporting each spray gun with a dry powder feeder and a flow control valve, this patent realizes the precise control of the powder amount of each spray gun. However, the system is complex and the investment cost is high, making it difficult to be popularized and applied in large coal-fired power plant boilers.

[0007] In summary, the currently disclosed patents related to the base dry powder adsorbent injection for SO 3 removal technology do not involve the homogeneous mixing distribution detection technology and device of the dry powder adsorbent. Although the base dry powder adsorbent injection for SO 3 removal system is applied to coal-fired power plant boilers, it belongs to the field of chemical machinery technology. To avoid problems in engineering applications, it is necessary to strictly follow the process of chemical machinery equipment development and only scale up for engineering promotion and application after successful verification in laboratory pilot tests. Summary of the Invention

[0008] An object of the present invention is to provide a general dry powder adsorbent homogeneous mixing distribution test device for conducting pilot tests of the base dry powder SO 3 adsorbent injection technology and device in the laboratory, and realizing the accurate measurement and analysis of the distribution uniformity of the SO 3 adsorbent at the outlet of the base dry powder injection device.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A dry powder adsorbent homogeneous mixing distribution test device includes a dry powder feeding unit, a compressed air supply unit, a dry powder injector, a dry powder homogeneous mixer, a dust collector, a blower, and a controller. The dry powder feeding unit and the compressed air supply unit are respectively connected to the dry powder injector. The dry powder injector is connected to the dry powder homogeneous mixer. The dry powder homogeneous mixer is connected to the dust collector. The dust collector is connected to the blower. The controller is connected to the dry powder feeding unit and the blower. The outlet of the dry powder homogeneous mixer is provided with a plurality of air-powder branch pipes. The dust collector includes a plurality of filter bags, and each air-powder branch pipe is connected to a filter bag.

[0011] Preferably, the dust collector further includes a box body provided with a door body and a plurality of air-powder inlet pipes provided on the box body. One end of each filter bag is detachably connected to an air-powder inlet pipe.

[0012] Further preferably, the air-powder inlet pipe is connected to the top of the box body, and the upper end of the filter bag is detachably connected to the air-powder inlet pipe.

[0013] Preferably, the compressed air supply unit includes an air compressor and a compressed air storage tank communicated with the air compressor, and the compressed air storage tank is communicated with the dry powder injector.

[0014] Further preferably, the compressed air supply unit further includes a cold dryer, and the air compressor and the compressed air storage tank are communicated through the cold dryer.

[0015] Preferably, the compressed air supply unit further includes a valve and a flowmeter arranged on the communication pipeline between the compressed air storage tank and the dry powder injector.

[0016] Preferably, the dry powder injector is a Venturi dry powder injector.

[0017] Preferably, the dry powder feeding unit is a screw feeder.

[0018] Preferably, the air-powder branch pipe is communicated with the filter bag through a corrugated hose.

[0019] Preferably, the dry powder mixing and distributing device is further provided with an air inlet.

[0020] Another object of the present invention is to provide a test method for uniformly mixing and distributing dry powder adsorbents, and this test method is completed by using the above test device.

[0021] To achieve the above object, the technical solution adopted by the present invention is:

[0022] A test method for uniformly mixing and distributing dry powder adsorbents, which includes:

[0023] 1). Adjust the rotation speed of the dry powder feeding unit through the controller, and calibrate the rotation speed - powder feeding amount relationship.

[0024] 2). Empty the filter bag in the dust collector, mark and weigh it, and record the weight of the filter bag before the test.

[0025] 3). Adjust the rotation speed of the fan through the controller to make the air speed inside the dry powder mixing and distributing device reach the designed value.

[0026] 4). Start the compressed air supply unit. After the pressure is stable, purge the adsorbent inlet pipelines of the dry powder injector and the dry powder mixing and distributing device.

[0027] 5), readjust the rotation speed of the dry powder feeding unit through the controller to make the adsorbent feeding amount reach the design value and start the test.

[0028] 6), After the test is completed, remove the filter bag and weigh it, and record the weight of the filter bag after the test.

[0029] 7), According to the weights of the filter bags before and after each test and the weights of the adsorbent in each air-powder branch pipe at the outlet of the dry powder mixing distributor, statistically analyze the uniformity of the adsorbent distribution.

[0030] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0031] The present invention can be used for the laboratory pilot test of the dry powder adsorbent mixing and distributing device, providing a test basis for the optimized design and engineering promotion and application of the technical device for injecting and removing SO by the base dry powder adsorbent. Moreover, it has a simple structure, is easy to use, and has high safety. 3 Technical device optimization design and engineering promotion application provide a test basis, and the structure is simple, easy to use, and has high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Attached Figure 1 is a schematic diagram of this embodiment;

[0033] Attached Figure 2 is a front view schematic diagram of the dust collector in this embodiment;

[0034] Attached Figure 3 is a side view schematic diagram of the dust collector in this embodiment.

[0035] In the above drawings:

[0036] 1. Dry powder feeding unit; 20. Air compressor; 21. Refrigerated dryer; 22. Compressed air storage tank; 23. Ball valve; 24. Flow meter; 3. Dry powder injector; 4. Dry powder mixing distributor; 40. Air-powder branch pipe; 5. Dust collector; 50. Box body; 51. Door body; 52. Air-powder inlet pipe; 53. Filter bag; 6. Fan; 7. Controller. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] As Figure 1 shown, a dry powder adsorbent mixing and dispensing test device includes a dry powder feeding unit 1, a compressed air supply unit, a dry powder injector 3, a dry powder mixing and dispensing device 4, a dust collector 5, a fan 6, and a controller 7. Among them:

[0041] The dry powder feeding unit 1 and the compressed air supply unit are respectively communicated with the powder feeding port on the upper part of the dry powder injector 3 and the air inlet at the front end. The dry powder injector 3 is communicated with the dry powder mixing and dispensing device 4, the dry powder mixing and dispensing device 4 is communicated with the dust collector 5, the dust collector 5 is communicated with the fan 6, and the controller 7 is connected to the dry powder feeding unit 1 and the fan 6. Specifically:

[0042] The dry powder feeding unit 1 adopts a screw feeder.

[0043] The compressed air supply unit includes an air compressor 20, a refrigerated dryer 21, and a compressed air storage tank 22. The air compressor 20 and the compressed air storage tank 22 are communicated through the refrigerated dryer 21. The compressed air storage tank 22 is communicated with the air inlet at the front end of the dry powder injector 3. In order to reduce the moisture in the compressed air, the compressed air at the outlet of the air compressor 20 first passes through the refrigerated dryer 21 for dehumidification and then enters the compressed air storage tank 22 for storage and standby. The compressed air supply unit also includes a ball valve 23 and a flowmeter 24 arranged on the connecting pipeline between the compressed air storage tank 22 and the dry powder injector 3. The flow rate of the compressed air entering the dry powder injector 3 is controlled and measured by the ball valve 23 and the flowmeter 24 at the outlet of the compressed air storage tank 22.

[0044] The dry powder injector 3 uses a Venturi dry powder injector. When compressed air flows through the throat of the Venturi dry powder injector at high speed, a negative pressure is generated, sucking and carrying away the dry powder adsorbent falling from the outlet of the dry powder feeding unit 1 and injecting it into the dry powder mixing and distributing device 4.

[0045] The dry powder mixing and distributing device 4 has an air-powder inlet, an outlet, and also an air inlet. Multiple air-powder branch pipes 40 are provided at the outlet of the dry powder mixing and distributing device 4.

[0046] As Figure 2 、 3 shown in

[0047] The dust collector 5 uses a bag filter, including a box body 50, a door body 51 that can be quickly opened and arranged on the box body, multiple air-powder inlet pipes 52 arranged at the top of the box body 50, and filter bags 53 with the upper ends connected to the air-powder inlet pipes 52. The multiple air-powder inlet pipes 52 correspond to the multiple air-powder branch pipes 40 one by one and are connected through corrugated hoses. In order to measure the powder amount of the dry powder adsorbent entering each dry powder adsorbent spray gun from the outlet of the dry powder mixing and distributing device 4, the dust collector 5 is designed as a quick-disassembly array filter bag structure, that is, the filter bags 53 are connected to the air-powder inlet pipes 52 through a quick-disassembly structure.

[0047] The fan 6 uses a centrifugal fan and is arranged at the outlet end of the test device. In order to prevent the dry powder adsorbent from leaking out, the fan 6 makes the test device form a negative pressure system, and uses the negative pressure generated by the fan 6 to suck air into the dry powder mixing and distributing device 4.

[0048] The fan frequency converter in the controller 7 adjusts the air flow rate entering the dry powder mixing and distributing device 4; the screw feeder frequency converter in the controller 7 adjusts the adsorbent flow rate entering the dry powder mixing and distributing device 4.

[0049] The powdery adsorbent enters the dry powder mixing and distributing device 4 through the dry powder injector 3 and is mixed with air in the dry powder mixing and distributing device 4. Then, the dry powder adsorbent entering each air-powder branch pipe 40 is collected by the filter bags 53 of the dust collector 5. Before and after the test, the filter bags 53 are removed one by one, weighed, and the weight of the filter bags 53 before the test is recorded. The weight of the adsorbent in each air-powder branch pipe 40 at the outlet of the dry powder mixing and distributing device 4 is calculated, and the distribution uniformity of the adsorbent is statistically analyzed.

[0050] The following specifically elaborates on the test process of this embodiment:

[0051] 1. Through the feeder frequency converter in the controller 7, adjust the rotation speed of the dry powder feeding unit 1 and calibrate the rotation speed - powder feeding amount relationship.

[0052] 2. Empty the filter bags 53 in the dust collector 5 one by one, mark and weigh them, and record the weight of the filter bags 53 before the test.

[0053] 3. Through the fan frequency converter in the controller 7, adjust the rotation speed of the fan 6 to make the air speed inside the dry powder mixing and distributing device 4 reach the design value.

[0054] 4. Start the air compressor 20 and the cold dryer 21. After the pressure of the compressed air storage tank 22 is stable, open the ball valve 23 to purge the adsorbent inlet pipes of the dry powder injector 3 and the dry powder mixing distributor 4.

[0055] 5. Adjust the speed of dry powder feeding unit 1 through the feeder inverter in the controller 7 so that the adsorbent feeding amount reaches the designed value, start the test, and run for 20 to 30 minutes.

[0056] 6. After the test, open the door 51 of the dust collector 5, remove the filter bags 53 one by one and weigh them, and record the weight of the filter bags 53 after the test.

[0057] 7. According to the weight of the filter bag 53 before and after each test, and the weight of the adsorbent in each air-powder branch pipe 40 at the outlet of the dry powder mixing distributor 4, the distribution uniformity of the adsorbent is statistically analyzed.

[0058] Example:

[0059] like Figure 1 The dry powder adsorbent homogeneous mixing and distribution test system shown in the figure has been used for the removal of SO by alkali dry powder injection. 3 In the research and development of the device, calcium oxide dry powder with a particle size of about 325 mesh was used as the adsorbent in the test, and 20 air-powder branches were set in the dry powder homogenizer; the dust collector was Figure 2 , 3 As shown, 20 air-powder inlet pipes and filter bags are set; the outer diameters of the air-powder branch pipe and the air-powder inlet pipe of the dust collector are consistent, both of which are 76mm; the inner diameter of the filter bag is consistent with the diameter of the air-powder inlet pipe, the length is 1200mm, and the dust filtration efficiency of particles with a diameter of 1μm and above is ≥99%; the air speed inside the dry powder mixing distributor is 7.5m / s, the adsorbent feed rate is 13.6kg / h, the test time is 30 minutes, and the test results are shown in Table 1. The average adsorbent dose of the 20 branch pipes is 340g, the maximum negative deviation is -11%, the maximum positive deviation is 8%, and the relative standard deviation is 5.5%.

[0060] Branch pipe 1 Branch pipe 2 Branch pipe 3 Branch pipe 4 Branch pipe 5 313 356 333 324 329 Branch pipe 6 Branch pipe 7 Branch pipe 8 Branch pipe 9 Branch pipe 10 311 337 342 368 304 Branch pipe 11 Branch pipe 12 Branch pipe 13 Branch pipe 14 Branch pipe 15 321 339 342 357 342 Branch pipe 16 Branch pipe 17 Branch pipe 18 Branch pipe 19 Branch pipe 20 350 352 355 369 359

[0061] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A test method for uniform mixing and distribution of dry powder adsorbent, characterized in that: This test method is realized through a test device for uniform mixing and distribution of dry powder adsorbent, The device includes: A dry powder feeding unit, a compressed air supply unit, a dry powder injector, a dry powder uniform mixing and distributor, a dust collector, a fan, and a controller. The dry powder feeding unit and the compressed air supply unit are respectively connected to the dry powder injector. The dry powder injector is connected to the dry powder uniform mixing and distributor. The dry powder uniform mixing and distributor is connected to the dust collector. The dust collector is connected to the fan. The controller is connected to the dry powder feeding unit and the fan. Multiple air-powder branch pipes are arranged at the outlet of the dry powder uniform mixing and distributor. The dust collector includes multiple filter bags, and each of the air-powder branch pipes is in one-to-one correspondence and communication with each of the filter bags. The method includes: 1), Adjust the rotation speed of the dry powder feeding unit through the controller, and calibrate the rotation speed - powder feeding amount relationship. 2), Empty the filter bags in the dust collector, mark and weigh them, and record the weight of the filter bags before the test. 3), Adjust the rotation speed of the fan through the controller to make the air speed inside the dry powder uniform mixing and distributor reach the design value. 4), Start the compressed air supply unit. After the pressure is stable, purge the adsorbent inlet pipes of the dry powder injector and the dry powder uniform mixing and distributor. 5), Adjust the rotation speed of the dry powder feeding unit again through the controller to make the adsorbent feeding amount reach the design value and start the test. 6), After the test is completed, remove the filter bags and weigh them, and record the weight of the filter bags after the test. 7), According to the weights of the filter bags before and after each test and the weights of the adsorbent in each air-powder branch pipe at the outlet of the dry powder uniform mixing and distributor, statistically analyze the distribution uniformity of the adsorbent.

2. The test method for uniform mixing and distribution of dry powder adsorbent according to claim 1, characterized in that: The dust collector further includes a box body provided with a door body and multiple air-powder inlet pipes arranged on the box body. One end of each filter bag is detachably connected to one of the air-powder inlet pipes.

3. The test method for uniform mixing and distribution of dry powder adsorbent according to claim 2, characterized in that: The air-powder inlet pipe is connected to the top of the box body, and the upper end of the filter bag is detachably connected to the air-powder inlet pipe.

4. The test method for uniform mixing and distribution of dry powder adsorbent according to claim 1, characterized in that: The compressed air supply unit includes an air compressor and a compressed air storage tank connected to the air compressor. The compressed air storage tank is connected to the dry powder injector.

5. The test method for uniform mixing and distribution of dry powder adsorbent according to claim 4, characterized in that: The compressed air supply unit further includes a refrigerated dryer, and the air compressor and the compressed air storage tank are connected through the refrigerated dryer.

6. The test method for uniform mixing and distribution of dry powder adsorbent according to claim 4, characterized in that: The compressed air supply unit further includes a valve and a flow meter disposed on the connecting pipeline between the compressed air storage tank and the dry powder injector.

7. The dry powder adsorbent uniform mixing and distribution test method according to claim 1, characterized in that: the dry powder injector is a Venturi dry powder injector; the dry powder feeding unit is a screw feeder.

8. The dry powder adsorbent uniform mixing and distribution test method according to claim 1, characterized in that: the air-powder branch pipe is communicated with the filter bag through a corrugated hose.

9. The dry powder adsorbent uniform mixing and distribution test method according to claim 1, characterized in that: the dry powder uniform mixing and distributor is further provided with an air inlet.

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