Pressurized fluidized bed gasifier

Abstract

The utility model discloses a pressurized fluidized bed gasifier, which relates to the technical field of solid waste treatment and comprises a gasifier device, a gas-solid separator and a circulating device, the gasification furnace device comprises a gasification furnace body, a gasification assembly and a first air feeder; a gasification gas outlet and a material returning opening are formed in the gasification furnace body; the gasification gas outlet is communicated with the gas input end of the gas-solid separator through a connecting pipe; the solid output end of the gas-solid separator is communicated with the material returning opening through a circulating device, and is used for circularly conveying the solid output by the gas-solid separator back into the gasification furnace body; the output end of the first air feeder is connected to the gasification furnace body and is used for pressurizing the interior of the gasification furnace body; the gasification furnace body comprises an upper furnace section, a transition furnace section and a lower furnace section; the transition furnace section is connected between the upper furnace section and the lower furnace section; the diameter of the lower furnace section is smaller than that of the upper furnace section; a dense-phase area is formed in the inner space of the lower furnace section. The design can improve the gasification conversion efficiency and solve the problem that the tail gas dust amount is too large.

Description

Technical Field

[0001] The present application relates to the technical field of solid waste treatment, and in particular to a pressurized fluidized bed gasifier. Background Art

[0002] Circulating fluidized bed boiler is one of the conventional boilers for treating solid waste. When used as a gasifier, circulating fluidized bed boiler has only been used in coal gasification. Coal fuel is gasified and burned in the boiler, and a redox reaction occurs to produce carbon monoxide. Usually, an induced draft fan is used to maintain a certain negative pressure in the boiler to facilitate the rapid flow of carbon monoxide and heat. However, under negative pressure conditions, the amount of excess oxygen needs to be increased. At the same time, the time the fuel stays in the boiler will also be shortened, so that it cannot be fully burned, resulting in increased incomplete combustion losses and excessive tail gas dust. Moreover, since the fuel stays in the boiler for a short time, in order to achieve the designed residence time, the furnace body must be made very large, which also leads to a larger overall volume of the equipment. Utility Model Content

[0003] In view of this, the purpose of this application is to provide a pressurized fluidized bed gasifier to solve the technical problems of large exhaust dust volume, large equipment volume, poor combustion stability and economy existing in the existing negative pressure circulating fluidized bed boiler.

[0004] In order to achieve the above technical purpose, the present application provides a pressurized fluidized bed gasifier, including a gasifier device, a gas-solid separator and a circulation device;

[0005] The gasifier device comprises a gasifier body, a gasifier assembly and a first blower;

[0006] The gasification assembly is installed on the gasification furnace body;

[0007] The gasification furnace body is provided with a gasification gas outlet and a material return port;

[0008] The gasification gas outlet is connected to the gas input end of the gas-solid separator through a connecting pipe;

[0009] The solid output end of the gas-solid separator is connected to the return port through the circulation device, so as to circulate the solid output from the gas-solid separator back to the gasification furnace body;

[0010] The output end of the first blower is connected to the gasification furnace body, and is used to pressurize the gasification furnace body;

[0011] The gasification furnace body comprises an upper furnace section, a transition furnace section and a lower furnace section;

[0012] The transition furnace section is connected between the upper furnace section and the lower furnace section;

[0013] The diameter of the lower furnace section is smaller than the diameter of the upper furnace section;

[0014] The inner space of the lower furnace section forms a dense phase area.

[0015] Furthermore, the upper furnace section and the lower furnace section are cylindrical;

[0016] The transition furnace section is in the shape of an inverted frustum.

[0017] Further, the gasification assembly includes an air distribution device, a first air nozzle and a second air nozzle;

[0018] The air distribution device is installed at the bottom of the gasification furnace body;

[0019] A slag discharge port is provided at the bottom of the air distribution device;

[0020] The first air nozzle is installed on the transition furnace section;

[0021] The second air nozzle is installed on the transition furnace section and is located below the first air nozzle.

[0022] Furthermore, the material return port is arranged on the lower furnace section;

[0023] The lower furnace section is also provided with a feed port;

[0024] The transition furnace section is provided with a liquid material inlet;

[0025] The gasification outlet is arranged at the top of the upper furnace section;

[0026] The outer side surface of the upper furnace section is also provided with a material injection port.

[0027] Furthermore, the feed port is connected to a first sealed pressure tank.

[0028] Furthermore, the slag discharge port is connected to a second sealed pressure tank.

[0029] Furthermore, there are multiple spraying ports, which are distributed in a circle.

[0030] Furthermore, the first air nozzles are multiple and distributed in a circumferential manner;

[0031] There are multiple second air nozzles distributed in a circle.

[0032] Furthermore, a hood is installed on the gasifier;

[0033] The output end of the first blower is connected to the hood.

[0034] Furthermore, the circulation device includes a material return device, an ash lowering pipe, a material return pipe and a second blower;

[0035] The solid output end of the gas-solid separator is connected to the input end of the return device through the ash lowering pipe;

[0036] The output end of the material return device is connected to the material return port through the material return pipe;

[0037] The material return device is provided with a material return air inlet;

[0038] The output end of the second blower is connected to the return material air inlet.

[0039] It can be seen from the above technical solutions that the pressurized fluidized bed gasifier designed in this application has the following beneficial effects:

[0040] 1. Add the first blower to keep the gasifier body pressurized and increase the residence time of the fuel in the gasifier body, which is conducive to the full reaction of the fuel in the gasifier body, improves the gasification conversion efficiency, and thus solves the problem of excessive tail gas dust.

[0041] 2. The gasification furnace body adopts a three-stage design, in which the diameter of the lower furnace section forming the dense phase area is designed to be smaller than the diameter of the upper furnace section, so that the dense phase area is designed to be closed, which is beneficial to improve the vulcanization speed and stability, and at the same time is beneficial to increase the temperature of the dense phase area and improve the adaptability of the fuel, especially for the use of low calorific value fuels.

[0042] 3. The pressurized design is helpful to reduce the volume of the pressurized fluidized bed gasifier, reduce tail gas emissions, reduce fan load, and reduce overall equipment energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 It is a schematic diagram of the structure of the pressurized fluidized bed gasifier provided in this application;

[0045] In the figure: 1. gasification furnace body; 2. upper furnace section; 3. transition furnace section; 4. lower furnace section; 5. air distribution device; 6. feed port; 7. liquid material inlet; 8. second air nozzle; 9. first air nozzle; 10. return port; 11. slag discharge port; 12. injection port; 13. gasification outlet; 14. connecting pipe; 15. gas-solid separator; 16. gas output end; 17. lower ash pipe; 18. return material; 19. return material inlet; 20. return material pipe. DETAILED DESCRIPTION

[0046] The technical solutions of the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all of them. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments in the embodiments of the present application are within the scope of protection of the embodiments of the present application.

[0047] In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0048] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a replaceable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0049] The embodiment of the present application discloses a pressurized fluidized bed gasifier.

[0050] See also Figure 1 , an embodiment of the pressurized fluidized bed gasifier provided in the embodiments of the present application includes:

[0051] Gasifier device, gas-solid separator 15 and circulation device.

[0052] The gasifier device comprises a gasifier body 1, a gasification assembly and a first blower (not shown).

[0053] The gasification assembly is installed on the gasification furnace body 1 .

[0054] The gasification furnace body 1 is provided with a gasification gas outlet 13 and a material return port 10 ; the gasification gas outlet 13 is connected to the gas input end of the gas-solid separator 15 through a connecting pipe 14 .

[0055] The solid output end of the gas-solid separator 15 is connected to the return port 10 through a circulation device, so as to circulate the solid output from the gas-solid separator 15 back to the gasification furnace body 1. The solid fly ash brought out by the raw synthesis gas of the gasification furnace is returned to the gasification furnace for recycling after separation, so that the carbon content in the discharged ash is reduced and the carbon conversion rate is significantly improved.

[0056] The output end of the first blower is connected to the gasification furnace body 1, which is used to pressurize the gasification furnace body 1; the gas output end 16 of the gas-solid separator 15 is connected to an induced draft fan, and the induced draft fan and the first blower cooperate to pressurize the gasification furnace body 1, so that a positive pressure state is maintained in the gasification furnace body 1.

[0057] The gasification furnace body 1 includes an upper furnace section 2 , a transition furnace section 3 and a lower furnace section 4 .

[0058] The transition furnace section 3 is connected between the upper furnace section 2 and the lower furnace section 4. The diameter of the lower furnace section 4 is smaller than the diameter of the upper furnace section 2. The internal space of the lower furnace section 4 forms a dense phase area, and the pressure in the dense phase area can be controlled at 2Mpa~2.5Mpa. It can be understood that the operating pressure is increased from normal pressure to 2.0MPa, thereby increasing the reaction speed and the production capacity per unit furnace area of ​​the gasifier.

[0059] The pressurized fluidized bed gasifier designed in this application has the following beneficial effects:

[0060] 1. Add a first blower to keep the gasification furnace body 1 pressurized and increase the residence time of the fuel in the gasification furnace body 1, which is conducive to the full reaction of the fuel in the gasification furnace body 1, improves the gasification conversion efficiency, and thus solves the problem of excessive tail gas dust.

[0061] 2. The gasification furnace body 1 adopts a three-stage design, in which the diameter of the lower furnace section 4 forming the dense phase area is designed to be smaller than the diameter of the upper furnace section 2, so that the dense phase area is designed to be closed, which is conducive to improving the sulfurization speed and stability, and at the same time, it is conducive to increasing the temperature of the dense phase area and improving the adaptability of the fuel, especially for the use of low calorific value fuels. Specifically, the original 900℃~950℃ can be increased to 950℃~1100℃, thereby improving the carbon conversion rate, increasing the synthesis gas output rate, reducing the CH4 content in the synthesis gas, and reducing the oxygen consumption.

[0062] 3. The pressurized design is helpful to reduce the volume of the pressurized fluidized bed gasifier and reduce the exhaust gas emissions. The reduction in volume can correspondingly reduce the load of the first blower (pressurized blower) and reduce the overall equipment energy consumption.

[0063] The pressurized fluidized bed gasifier designed in the present application achieves an increase in gasification pressure and gasification temperature, making it possible to scale up the gasifier.

[0064] The above is the first embodiment of the pressurized fluidized bed gasifier provided in the embodiment of the present application. The following is the second embodiment of the pressurized fluidized bed gasifier provided in the embodiment of the present application. For details, please refer to Figure 1 .

[0065] Based on the solution of the above embodiment 1:

[0066] Furthermore, the upper furnace section 2 and the lower furnace section 4 are cylindrical in shape, the transition furnace section 3 is in the shape of an inverted cone, and the gasification furnace body 1 is shaped like an inverted gourd as a whole.

[0067] Furthermore, the gasification assembly includes an air distribution device 5, a first air nozzle 9 and a second air nozzle 8. When used, the first air nozzle 9 and the second air nozzle 8 use two different gasification agents, such as oxygen-enriched and water vapor.

[0068] The air distribution device 5 is installed at the bottom of the gasification furnace body 1, and a slag discharge port 11 is provided at the bottom of the air distribution device 5. The air distribution device 5 is for the purpose of uniform airflow distribution, and at the same time avoids local overheating and slagging caused by gas channeling inside the bed layer, prolongs the service life, and reduces maintenance costs; the gasification furnace body 1 of the present application is provided with an air port connected to the furnace cavity through the air distribution device 5, and a certain amount of air is provided through the air port and the air distribution device 5 to control and maintain the gasification combustion temperature. The air distribution device 5 adopts an air distribution mechanism with mature industry technologies such as a grate and a hood, which will not be described in detail.

[0069] The first air nozzle 9 is installed on the transition furnace section 3 ; the second air nozzle 8 is installed on the transition furnace section 3 and is located below the first air nozzle 9 .

[0070] Furthermore, a return port 10 is provided on the lower furnace section 4 , and a feed port 6 is also provided on the lower furnace section 4 .

[0071] The transition furnace section 3 is provided with a liquid material inlet 7. The liquid material inlet can be used to add high calorific value waste oil. The liquid material inlet 7 can also be used to change the process to a wet fluidized bed pressurized gasification process design.

[0072] The gasification outlet 13 is arranged at the top of the upper furnace section 2 , and the outer side surface of the upper furnace section 2 is also provided with a material injection port 12 .

[0073] Furthermore, the feed port 6 is connected to a first sealed pressure tank to ensure the stability of fuel feeding. The fuel can be pre-treated by a pre-treatment device before feeding to make the fuel into particles with uniform particle size, which is conducive to ensuring the stability of gasification and fluidization; the feed port 6 can also be connected to a sealed fuel conveyor.

[0074] Furthermore, the slag discharge port 11 is connected to a second sealed pressure tank to facilitate unloading and pressure stabilization.

[0075] In the present application, both the feed port 6 and the slag discharge port 11 are connected to a pressure tank, which is beneficial to the pressure stability of the feed and avoids the risk of tempering and returning the material due to pressurization.

[0076] Furthermore, there are multiple spray ports 12 distributed in a circle, and the spray ports 12 are used to spray water vapor or cooling water.

[0077] Furthermore, there are multiple first air nozzles 9 distributed in a circumference.

[0078] Correspondingly, the second air nozzles 8 may also be designed to be multiple and distributed around the circumference.

[0079] Furthermore, a hood (not shown) is installed on the gasifier, and the output end of the first blower is connected to the hood.

[0080] Furthermore, the circulation device includes a return device 18, an ash lowering pipe 17, a return pipe 20 and a second blower (not shown).

[0081] The solid output end of the gas-solid separator 15 is connected to the input end of the return device 18 through the ash lower pipe 17.

[0082] The output end of the return device 18 is connected to the return port 10 through the return pipe 20 . The return device 18 is provided with a return air inlet 19 . The output end of the second blower is connected to the return air inlet 19 .

[0083] Ignitors are provided in the transition furnace section 3 and the lower furnace section 4. By adopting the bed ignition (ignition in the transition furnace section 3) + under-bed ignition (ignition in the lower furnace section 4), the heating rate is controllable, the fuel utilization rate is high, the ignition success rate is high, the low-temperature section is mainly ignited under the bed, and the high-temperature section starts the bed ignition. There is a burning flame in the furnace, the temperature of the flame-covered area is high, and it is conducive to the ignition and combustion of the newly-input fuel.

[0084] The pressurized fluidized bed gasifier designed in the present application can be used for solid waste treatment, sludge treatment, hazardous waste treatment and coupled with power plant boiler coordination.

[0085] The above is a detailed introduction to the pressurized fluidized bed gasifier provided in the present application. For a person skilled in the art, according to the concept of the embodiments of the present application, there may be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A pressurized fluidized bed gasifier, characterized in that: It comprises a gasification furnace device, a gas-solid separator (15) and a circulation device; The gasification furnace device comprises a gasification furnace body (1), a gasification component and a first blower; The gasification assembly is installed on the gasification furnace body (1); The gasification furnace body (1) is provided with a gasification gas outlet (13) and a material return port (10); The gasification gas outlet (13) is connected to the gas input end of the gas-solid separator (15) via a connecting pipe (14); The solid output end of the gas-solid separator (15) is connected to the return port (10) through the circulation device, so as to circulate the solid output from the gas-solid separator (15) back into the gasification furnace body (1); The output end of the first blower is connected to the gasification furnace body (1) and is used to pressurize the inside of the gasification furnace body (1); The gasification furnace body (1) comprises an upper furnace section (2), a transition furnace section (3) and a lower furnace section (4); The transition furnace section (3) is connected between the upper furnace section (2) and the lower furnace section (4); The diameter of the lower furnace section (4) is smaller than the diameter of the upper furnace section (2); The inner space of the lower furnace section (4) forms a dense phase area.

2. The pressurized fluidized bed gasifier according to claim 1, characterized in that: The upper furnace section (2) and the lower furnace section (4) are cylindrical in shape; The transition furnace section (3) is in the shape of an inverted frustum.

3. The pressurized fluidized bed gasifier according to claim 1, characterized in that: The gasification component comprises an air distribution device (5), a first air nozzle (9) and a second air nozzle (8); The air distribution device (5) is installed at the bottom of the gasification furnace body (1); The bottom of the air distribution device (5) is provided with a slag discharge port (11); The first air nozzle (9) is installed on the transition furnace section (3); The second air nozzle (8) is installed on the transition furnace section (3) and is located below the first air nozzle (9).

4. The pressurized fluidized bed gasifier according to claim 3, characterized in that: The material return port (10) is arranged on the lower furnace section (4); The lower furnace section (4) is also provided with a feed inlet (6); The transition furnace section (3) is provided with a liquid material inlet (7); The gasification outlet (13) is arranged at the top of the upper furnace section (2); The outer side surface of the upper furnace section (2) is also provided with a material injection port (12).

5. The pressurized fluidized bed gasifier according to claim 4, characterized in that: The feed port (6) is connected to a first sealed pressure tank.

6. The pressurized fluidized bed gasifier according to claim 4, characterized in that: The slag discharge port (11) is connected to a second sealed pressure tank.

7. The pressurized fluidized bed gasifier according to claim 4, characterized in that: The material spraying ports (12) are multiple and distributed in a circular pattern.

8. The pressurized fluidized bed gasifier according to claim 4, characterized in that: The first air nozzles (9) are multiple and distributed in a circumferential manner; The second air nozzles (8) are multiple and distributed in a circumferential manner.

9. The pressurized fluidized bed gasifier according to claim 1, characterized in that: The gasifier is provided with a hood; The output end of the first blower is connected to the hood.

10. The pressurized fluidized bed gasifier according to claim 1, characterized in that: The circulation device comprises a material return device (18), an ash lowering pipe (17), a material return pipe (20) and a second blower; The solid output end of the gas-solid separator (15) is connected to the input end of the return device (18) via the ash lowering pipe (17); The output end of the material return device (18) is connected to the material return port (10) via the material return pipe (20); The material return device (18) is provided with a material return air inlet (19); The output end of the second blower is connected to the return air inlet (19).

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