SDS (Sodium Dodecyl Sulfate) dry desulfurization system of biomass boiler

Abstract

The invention discloses a biomass boiler SDS (Sodium Dodecyl Sulfate) dry desulfurization system which comprises a control device as well as a flue gas input pipeline, a pretreatment chamber, a first pipeline, a multi-stage reactor, a second pipeline, a cyclone separator, a third pipeline and a chimney which are sequentially arranged along a flue gas flowing direction, and the multi-stage reactor comprises a horizontally distributed reactor body and three reaction chambers; the temperatures and the humidity of the three reaction chambers are gradually reduced in the flue gas flowing direction; the first pipeline is connected with a desulfurizing agent adding device, and the desulfurizing agent adding device comprises a fourth pipeline, a fluidized bed type stock bin, an air blower and a mixing acceleration chamber. By optimizing the injection mode, increasing the reaction area and recovering the desulfurizing agent, the contact efficiency and the reaction time of the desulfurizing agent and the flue gas are remarkably improved, the desulfurization efficiency is greatly improved, and the operation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of boiler flue gas desulfurization, and particularly to a biomass boiler SDS dry desulfurization system. Background Art

[0002] During the combustion process of biomass boilers, a large amount of sulfur dioxide (SO2) is generated, causing serious environmental pollution.

[0003] The existing SDS dry desulfurization technology usually uses sodium bicarbonate (NaHCO3) as a desulfurizing agent, and uses a spraying device to spray the desulfurizing agent powder into the flue gas duct. Active sodium is generated through high-temperature decomposition, and a chemical reaction occurs with SO2 to generate sodium sulfate (Na2SO4) and carbon dioxide (CO2). However, the existing technology has problems such as uneven dispersion of the desulfurizing agent powder, short contact time between the desulfurizing agent and the flue gas resulting in insufficient reaction, and low desulfurization efficiency.

[0004] Therefore, how to optimize the dispersion of the desulfurizing agent powder, extend the reaction time, and improve the desulfurization reaction efficiency urgently needs to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a biomass boiler SDS dry desulfurization system. By optimizing the spraying method, increasing the reaction zone, and recycling the desulfurizing agent, the contact efficiency and reaction time between the desulfurizing agent and the flue gas are significantly improved, the desulfurization efficiency is greatly increased, and the operation cost is reduced, thus well solving the problems mentioned in the above background art.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions: The present invention provides a biomass boiler SDS dry desulfurization system, including a control device and a pretreatment chamber, a multi-stage reactor, a cyclone separator, and a chimney arranged in sequence along the flue gas flow direction. The intake end of the pretreatment chamber is connected to the exhaust port of the biomass boiler through a flue gas input pipeline. The outlet end of the pretreatment chamber is connected to the intake end of the multi-stage reactor through a first pipeline. The outlet end of the multi-stage reactor is connected to the intake end of the cyclone separator through a second pipeline. The outlet end of the cyclone separator is connected to the lower part of the chimney through a third pipeline. The multi-stage reactor includes a reactor body horizontally distributed and three reaction chambers connected in sequence horizontally inside the reactor body. The temperature and humidity of the three reaction chambers are gradually decreased along the flue gas flow direction. The first pipeline is connected with a desulfurizing agent adding device, and the desulfurizing agent adding device includes a fourth pipeline and a fluidized bed type bin for storing desulfurizing agent powder. A gas distribution plate is arranged at the lower part of the inner cavity of the fluidized bed type bin. A blower is connected to the bottom of the fluidized bed type bin. The top of the fluidized bed type bin is connected to the fourth pipeline, and the fourth pipeline is connected to the first pipeline through a mixing and accelerating chamber.

[0007] Further, the pretreatment chamber includes a hollow filter box and a stainless steel filter screen installed in the inner cavity of the filter box. The aperture of the stainless steel filter screen is 50μm - 100μm.

[0008] Further, the gas distribution plate adopts a stainless steel perforated plate structure with an aperture of 1mm - 3mm and a porosity of 30% - 50%.

[0009] Further, the outer wall of the fluidized bed type silo is provided with a heat preservation sleeve, and the inner wall of the fluidized bed type silo is provided with a heating device.

[0010] Further, the heating device includes a heating layer fixed on the inner wall of the fluidized bed type silo, a temperature controller, and nickel-chromium alloy heating wires with a diameter of 1mm - 2mm evenly distributed in the heating layer.

[0011] Further, the three reaction chambers are respectively a high-temperature and high-humidity reaction chamber, a medium-temperature and medium-humidity reaction chamber, and a low-temperature and low-humidity reaction chamber; the temperature of the high-temperature and high-humidity reaction chamber is 120°C - 150°C, and the humidity is 30% - 40%; the temperature of the medium-temperature and medium-humidity reaction chamber is 100°C - 120°C, and the humidity is 20% - 30%; the temperature of the low-temperature and low-humidity reaction chamber is 80°C - 100°C, and the humidity is 10% - 20%.

[0012] Further, a temperature sensor and a cooling device for adjusting the flue gas temperature are arranged in the inner cavity of the reactor body. The cooling device includes a cooling copper coil through which circulating cooling water passes and a water passing valve installed on the cooling copper coil. The pipe diameter of the cooling copper coil is 5mm - 10mm.

[0013] Further, a humidity sensor and a humidity adjustment device for adjusting the flue gas humidity are also arranged in the inner cavity of the reactor body. The humidity adjustment device includes a humidifying nozzle for spraying water mist and a blowing port for blowing in dry air. The humidifying nozzle is sequentially connected with a humidifying pipeline, a water pump, and a water tank. The blowing port is connected with a return air pipe communicated with the chimney, and a return air fan and a return air valve are installed on the return air pipe.

[0014] Further, a rotary feeder is arranged at the bottom of the cyclone separator. The bottom of the rotary feeder is connected with a desulfurizer recovery device. The desulfurizer recovery device includes a fifth pipeline connected between the rotary feeder and the fluidized bed type silo and an accelerator installed on the fifth pipeline. The accelerator is connected with a first booster fan.

[0015] Further, a dust removal device and a second booster fan are arranged on the third pipeline. The dust removal device is a pulse jet bag filter.

[0016] Compared with the prior art, the present invention provides a biomass boiler SDS dry desulfurization system, which has the following beneficial effects: (1) The fluidized bed technology is adopted to store sodium bicarbonate powder, and the desulfurizer is evenly sprayed into the flue gas at the mixing and accelerating chamber by means of pneumatic conveying formed by a blower, which can improve the uniformity of the mixing of the desulfurizer powder and the flue gas.

[0017] (2) A multi-stage reactor design is adopted. By setting multiple reaction chambers, each reaction chamber has different temperature and humidity conditions to carry out the desulfurization reaction in stages, improving the desulfurization efficiency; at the same time, the flue gas changes its flow direction multiple times in the multi-stage reactor, extending the contact time between the desulfurizer and the flue gas, and also improving the reaction efficiency.

[0018] (3) The unreacted desulfurizer is separated by a cyclone separator to realize the recovery and recycling of the desulfurizer, reduce the consumption of the desulfurizer, and reduce the operating cost.

[0019] (4) A pretreatment chamber is arranged before the desulfurization reaction, which can remove the particulate matter in the flue gas and further improve the desulfurization reaction efficiency.

[0020] In addition, the overall structure is simple and easy to maintain. The automation and precision of the desulfurization process can be realized through intelligent control, significantly improving the desulfurization efficiency and desulfurizer utilization rate of the biomass boiler SDS dry desulfurization device, reducing the maintenance cost, and having good market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 is the structural schematic diagram of the present invention; Figure 2 is the structural schematic diagram of the pretreatment chamber; Figure 3 is the structural schematic diagram of the fluidized bed type silo; Figure 4 is the structural schematic diagram of the multi-stage reactor.

[0023] Reference numerals: 1, flue gas inlet pipe; 2, pretreatment chamber; 21, filter box; 22, stainless steel filter screen; 3, first pipe; 31, fourth pipe; 32, fluidized bed bin; 321, gas distribution plate; 322, heat preservation sleeve; 323, heating layer; 324, temperature controller; 33, blower; 34, mixing and accelerating chamber; 4, multi-stage reactor; 41, reactor body; 42, high-temperature and high-humidity reaction chamber; 43, medium-temperature and medium-humidity reaction chamber; 44, low-temperature and low-humidity reaction chamber; 45, temperature sensor; 46, cooling device; 461, cooling copper coil pipe; 462, water inlet valve; 47, humidity sensor; 48, humidity regulating device; 481, humidifying nozzle; 482, air outlet; 483, humidifying pipeline; 484, water pump; 485, water tank; 486, return air duct; 487, return air fan; 488, return air valve; 5, second pipe; 6, cyclone separator; 61, rotary feeder; 62, fifth pipe; 63, accelerator; 64, first booster fan; 7, third pipe; 71, dust removal device; 72, second booster fan; 8, chimney. Detailed implementation manners

[0024] The technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0025] The present invention will be further described in detail below through detailed embodiments in conjunction with the accompanying drawings.

[0026] Refer to Figures 1 to 4, this embodiment provides a biomass boiler SDS dry desulfurization system, including a control device (not shown in the figure) and a pretreatment chamber 2, a multi-stage reactor 4, a cyclone separator 6 and a chimney 8 arranged in sequence along the flue gas flow direction. The intake end of the pretreatment chamber 2 is connected to the exhaust port of the biomass boiler through a flue gas input pipeline 1. The outlet end of the pretreatment chamber 2 is connected to the intake end of the multi-stage reactor 4 through a first pipeline 3. The outlet end of the multi-stage reactor 4 is connected to the intake end of the cyclone separator 6 through a second pipeline 5. The outlet end of the cyclone separator 6 is connected to the lower part of the chimney 8 through a third pipeline 7. The multi-stage reactor 4 includes a reactor body 41 distributed horizontally and three reaction chambers connected in sequence horizontally inside the reactor body 41. The temperature and humidity of the three reaction chambers are gradually decreased along the flue gas flow direction. The first pipeline 3 is connected with a desulfurizer adding device. The desulfurizer adding device includes a fourth pipeline 31 and a fluidized bed type silo 32 for storing desulfurizer powder. A gas distribution plate 321 is arranged at the lower part of the inner cavity of the fluidized bed type silo 32. The bottom of the fluidized bed type silo 32 is connected with a blower 33 for providing fluidizing air. The top of the fluidized bed type silo 32 is connected to the fourth pipeline 31. The fourth pipeline 31 is connected to the first pipeline 3 through a mixing and accelerating chamber 34.

[0027] Thus, on the first hand, the fluidized bed technology is adopted to store sodium bicarbonate powder, and the desulfurizer is evenly sprayed into the flue gas at the mixing and accelerating chamber through the pneumatic conveying method formed by the blower, which can improve the uniformity of the mixing of the desulfurizer powder and the flue gas. On the second hand, the multi-stage reactor design is adopted. By setting multiple reaction chambers connected in series in sequence, each reaction chamber has different temperature and humidity conditions to carry out the desulfurization reaction in stages, improving the desulfurization efficiency. At the same time, the flue gas changes its flow direction multiple times in the multi-stage reactor, prolonging the contact time between the desulfurizer and the flue gas and also improving the reaction efficiency. On the third hand, the unreacted desulfurizer is separated by the cyclone separator to realize the recovery and recycling of the desulfurizer, reducing the desulfurizer consumption and the operation cost. On the fourth hand, a pretreatment chamber is arranged before the desulfurization reaction, which can remove the particulate matter in the flue gas and further improve the desulfurization reaction efficiency. In addition, the overall structure is simple and convenient to maintain, and the automation and precision of the desulfurization process can be realized through intelligent control.

[0028] In some specific embodiments, referring to Figure 1 and Figure 2 , the pretreatment chamber 2 includes a hollow filter box 21 and a stainless steel filter screen 22 installed in the inner cavity of the filter box 21. The aperture of the stainless steel filter screen 22 is 50μm - 100μm.

[0029] More specifically, the stainless steel filter screen is fixed in the inner cavity of the filter box through a card slot.

[0030] In some specific embodiments, the gas distribution plate 321 adopts a stainless steel perforated plate structure. The pore diameter can be set to 1 mm to 3 mm, and the porosity can be set to 30% to 50%, which can ensure uniform air distribution, prevent powder accumulation and enable the desulfurizer powder to be fully dispersed. As an example, the pore diameter of the gas distribution plate can be set to 1 mm and the porosity can be set to 40%.

[0031] More specifically, the gas distribution plate can be installed in the lower part of the inner cavity of the fluidized bed type silo through a flange.

[0032] As an improved embodiment, referring to Figure 1 and Figure 3 , a heat preservation sleeve 322 is provided on the outer wall of the fluidized bed type silo 32, and a heating device is provided on the inner wall of the fluidized bed type silo 32. Specifically, as shown in Figure 3 , the heating device includes a heating layer 323 fixed on the inner wall of the fluidized bed type silo 32, a temperature controller 324, and nickel-chromium alloy heating wires with a diameter of 1 mm to 2 mm evenly distributed in the heating layer 323. The temperature inside the fluidized bed type silo is controlled by the temperature controller at 30°C to 50°C to prevent the sodium bicarbonate desulfurizer from getting damp and caking, and improve the storage stability of the desulfurizer.

[0033] In some specific embodiments, referring to Figure 1 and Figure 4 , the three reaction chambers are respectively a high-temperature and high-humidity reaction chamber 42, a medium-temperature and medium-humidity reaction chamber 43, and a low-temperature and low-humidity reaction chamber 44; the temperature of the high-temperature and high-humidity reaction chamber 42 is 120°C to 150°C, and the humidity is 30% - 40%; the temperature of the medium-temperature and medium-humidity reaction chamber 43 is 100°C to 120°C, and the humidity is 20% - 30%; the temperature of the low-temperature and low-humidity reaction chamber 44 is 80°C to 100°C, and the humidity is 10% - 20%. By setting different temperature and humidity conditions for each reaction chamber respectively, the desulfurization reaction is carried out in stages, thereby improving the desulfurization efficiency. In addition, the high-temperature and high-humidity reaction chamber and the medium-temperature and medium-humidity reaction chamber are separated by a partition respectively, and the lower part of the high-temperature and high-humidity reaction chamber is communicated with the lower part of the medium-temperature and medium-humidity reaction chamber, and the upper part of the medium-temperature and medium-humidity reaction chamber is communicated with the upper part of the low-temperature and low-humidity reaction chamber. In this way, the flue gas will change its flow direction many times in the multi-stage reactor, greatly prolonging the contact time between the desulfurizer and the flue gas, making the desulfurization reaction more complete and thorough, and thus improving the reaction efficiency.

[0034] Specifically, as shown in Figure 4As shown, a temperature sensor 45 and a cooling device 46 for adjusting the flue gas temperature are arranged in the inner cavity of the reactor body 41. As an example, the cooling device 46 includes a cooling copper coil 461 through which circulating cooling water passes and a water valve 462 installed on the cooling copper coil 461. The pipe diameter of the cooling copper coil 461 can be set to 5 mm to 10 mm. In this way, the flue gas temperature can be gradually reduced by introducing circulating cooling water, thereby achieving the purpose of adjusting the flue gas temperature.

[0035] Specifically, as Figure 1 and Figure 4 shown, a humidity sensor 47 and a humidity adjustment device 48 for adjusting the flue gas humidity are also arranged in the inner cavity of the reactor body 41. As an example, the humidity adjustment device 48 includes a humidifying nozzle 481 for spraying water mist and a blowing port 482 for blowing in dry air. The humidifying nozzle 481 is sequentially connected with a humidifying pipeline 483, a water pump 484 and a water tank 485. The blowing port 482 is connected with a return air pipe 486 communicating with the chimney 8, and a return air fan 487 and a return air valve 488 are installed on the return air pipe 486. In this way, the humidity can be increased by spraying water mist with the humidifying nozzle and the humidity can be reduced by blowing in dry air with the blowing port, thereby achieving the purpose of adjusting the flue gas humidity.

[0036] In some specific embodiments, referring to Figure 1 , a rotary feeder 61 is arranged at the bottom of the cyclone separator 6, and the bottom of the rotary feeder 61 is connected with a desulfurizer recovery device. As an example, the desulfurizer recovery device includes a fifth pipeline 62 connected between the rotary feeder 61 and the fluidized bed type bin 32 and an accelerator 63 installed on the fifth pipeline 62. The accelerator 63 is connected with a first booster fan 64. In this way, the recovered desulfurizer can be returned to the fluidized bed type bin by means of pneumatic conveying to realize the recycling of the desulfurizer.

[0037] It should be noted that both the mixing and accelerating chamber 34 and the accelerator 63 are three-way Venturi injection mixers, which can quickly suck in materials under the action of air flow to complete the purpose of mixing and conveying. Their structures are common structures in the field of material pipeline transportation, so they will not be described in detail.

[0038] As an improved embodiment, referring to Figure 1 , a dust removal device 71 and a second booster fan 72 are further arranged on the third pipeline 7. The dust removal device 71 can be a pulse jet bag filter.

[0039] In addition, the control device is used to control the operating states of various devices. Specifically, the control device can adopt a PLC controller with programming functions.

[0040] The above embodiments are only illustrative of the concept and technical solutions of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

[0041] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A biomass boiler SDS dry desulfurization system, characterized in that: It includes a control device, as well as a pretreatment chamber, a multi-stage reactor, a cyclone separator, and a chimney arranged in sequence along the flue gas flow direction. The intake end of the pretreatment chamber is connected to the smoke exhaust port of the biomass boiler through a flue gas input pipeline. The outlet end of the pretreatment chamber is connected to the intake end of the multi-stage reactor through a first pipeline. The outlet end of the multi-stage reactor is connected to the intake end of the cyclone separator through a second pipeline. The outlet end of the cyclone separator is connected to the lower part of the chimney through a third pipeline. The multi-stage reactor includes a horizontally distributed reactor body and three reaction chambers arranged in sequence along the horizontal direction and connected inside the reactor body. The temperatures and humidities of the three reaction chambers are set to gradually decrease along the flue gas flow direction. The first pipeline is connected with a desulfurizing agent adding device, and the desulfurizing agent adding device includes a fourth pipeline and a fluidized bed type silo for storing desulfurizing agent powder. A gas distribution plate is arranged at the lower part of the inner cavity of the fluidized bed type silo. The bottom of the fluidized bed type silo is connected with a blower. The top of the fluidized bed type silo is connected to the fourth pipeline, and the fourth pipeline is connected to the first pipeline through a mixing and accelerating chamber.

2. The biomass boiler SDS dry desulfurization system according to claim 1, characterized in that, The pretreatment chamber includes a hollow filter box and a stainless steel filter screen installed in the inner cavity of the filter box. The aperture of the stainless steel filter screen is 50μm - 100μm.

3. The biomass boiler SDS dry desulfurization system according to claim 1, characterized in that, The gas distribution plate adopts a stainless steel perforated plate structure with an aperture of 1mm - 3mm and a porosity of 30% - 50%.

4. The biomass boiler SDS dry desulfurization system according to claim 1, characterized in that, The outer wall of the fluidized bed type silo is provided with a heat preservation sleeve, and the inner wall of the fluidized bed type silo is provided with a heating device.

5. The biomass boiler SDS dry desulfurization system according to claim 4, characterized in that, The heating device includes a heating layer fixed on the inner wall of the fluidized bed type silo, a temperature controller, and nickel-chromium alloy heating wires with a diameter of 1mm - 2mm evenly distributed in the heating layer.

6. The biomass boiler SDS dry desulfurization system according to claim 1, characterized in that: The three reaction chambers are respectively a high-temperature and high-humidity reaction chamber, a medium-temperature and medium-humidity reaction chamber, and a low-temperature and low-humidity reaction chamber. The temperature of the high-temperature and high-humidity reaction chamber is 120°C - 150°C, and the humidity is 30% - 40%. The temperature of the medium-temperature and medium-humidity reaction chamber is 100°C - 120°C, and the humidity is 20% - 30%. The temperature of the low-temperature and low-humidity reaction chamber is 80°C - 100°C, and the humidity is 10% - 20%.

7. The biomass boiler SDS dry desulfurization system according to claim 6, characterized in that: A temperature sensor and a cooling device for adjusting the flue gas temperature are arranged in the inner cavity of the reactor body. The cooling device includes a cooling copper coil through which circulating cooling water passes and a water passing valve installed on the cooling copper coil. The pipe diameter of the cooling copper coil is 5mm - 10mm.

8. The biomass boiler SDS dry desulfurization system according to claim 6, characterized in that, A humidity sensor and a humidity adjusting device for adjusting the flue gas humidity are also arranged in the inner cavity of the reactor body. The humidity adjusting device includes a humidifying nozzle for spraying water mist and a blowing port for blowing in dry air. The humidifying nozzle is sequentially connected with a humidifying pipeline, a water pump, and a water tank. The blowing port is connected with a return air pipe communicated with the chimney, and the return air pipe is provided with a return air fan and a return air valve.

9. The biomass boiler SDS dry desulfurization system according to claim 1, characterized in that, A rotary feeder is provided at the bottom of the cyclone separator, and a desulfurizer recovery device is connected to the bottom of the rotary feeder. The desulfurizer recovery device includes a fifth pipe connected between the rotary feeder and the fluidized bed silo and an accelerator installed on the fifth pipe, and the accelerator is connected to a first booster fan.

10. The biomass boiler SDS dry desulfurization system according to claim 1, characterized in that, The third pipeline is provided with a dust removal device and a second booster fan, and the dust removal device is a pulse back-blowing bag dust collector.

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