A microwave drying-activation-combustion-supporting method for biomass briquette fuel

Abstract

A microwave drying, activation and combustion-supporting method for biomass molded fuel belongs to the field of drying technology. The present invention is to solve the problem that the heat in the boiler will be consumed during the preheating process of biomass molded fuel. The biomass molded fuel is heated and dried by microwaves generated by a first microwave generator and a second microwave generator. The biomass molded fuel becomes loose after the moisture is precipitated, which is beneficial to the heat and mass transfer during the combustion process. The discharge port can be directly connected to the feed port of the biomass boiler. The first microwave generator and the second microwave generator assist each other in working together to achieve the best drying effect and realize continuous drying output of biomass molded fuel. The present invention separates the drying process of biomass molded fuel from the combustion process in the boiler, which can promote the combustion process of the fuel in the boiler and reduce the energy consumption of the boiler during the preheating stage.

Description

Technical Field

[0001] The invention belongs to the technical field of drying, and in particular relates to a microwave drying-activation-combustion-supporting method for biomass molded fuel. Background Art

[0002] Biomass molded fuel is a new type of fuel that can be directly burned and is made from agricultural and forestry waste as raw materials through processes such as crushing, mixing, extrusion, and drying. It has the advantages of high calorific value, no production of sulfur dioxide and phosphorus pentoxide during combustion, and thus no acid rain, no pollution to the atmosphere, and no pollution to the environment. The ash after combustion is high-quality organic potassium fertilizer that can feed back to agriculture.

[0003] Although biomass molded fuel is dried before leaving the factory, it is easy to absorb moisture during storage. When a biomass boiler burns biomass molded fuel, it first preheats the incoming biomass molded fuel. At this time, the biomass molded fuel entering the boiler is mixed with air, the temperature rises, and the moisture in the fuel evaporates. However, the preheating process of the biomass molded fuel will consume heat in the boiler. Summary of the invention

[0004] The purpose of the present invention is to provide a microwave drying-activation-combustion-supporting method for biomass pellet fuel, so as to solve the problem that the biomass pellet fuel consumes the heat in the boiler during the preheating process. The technical solution adopted by the present invention is as follows:

[0005] A microwave drying-activation-combustion-supporting method for biomass briquette fuel comprises the following steps:

[0006] Step 1: Detect the humidity of the biomass briquette fuel to be burned, and preliminarily adjust the power of each magnetron of the first microwave generating device and the second microwave generating device according to the humidity data obtained by the detection;

[0007] Step 2: close the second rotary feeding valve, start the first rotary feeding valve, put the biomass molding fuel into the feeding hopper, the biomass molding fuel fills the microwave combustion-supporting chamber through the first rotary feeding valve, start all the magnetrons on the first microwave generating device and the second microwave generating device, and the magnetrons emit microwaves to heat and dry the biomass molding fuel;

[0008] Step 3: When the humidity data collected by the second humidity sensor meets the feeding requirements of the biomass boiler, the second rotary feeding valve is started to allow the biomass shaped fuel that has completed drying, activation and combustion to enter the biomass boiler;

[0009] Step 4: Set the rotation speeds of the first rotary feeding valve and the second rotary feeding valve so that the feed amount and the discharge amount of the combustion-supporting cylinder are equal;

[0010] Step 5: adjusting the power of several magnetrons of the second microwave generating device so that the humidity data collected by the second humidity sensor remains within the feed humidity range of the biomass boiler;

[0011] Step 6: When the humidity data collected by the second humidity sensor still exceeds the feed humidity range of the biomass boiler after adjusting the powers of the magnetrons of the second microwave generating device, the powers of the magnetrons of the first microwave generating device are further adjusted to keep the humidity data collected by the second humidity sensor within the feed humidity range of the biomass boiler;

[0012] Step 7. Repeat steps 4 to 6 until the rotation speeds of the first rotary feeding valve and the second rotary feeding valve remain constant, the powers of the magnetrons of the first microwave generating device and the second microwave generating device are constant, and the humidity data collected by the second humidity sensor remains within the feed humidity range of the biomass boiler, thereby achieving continuous feeding of the biomass molded fuel.

[0013] Further, it includes a combustion-aiding cylinder, the first microwave generating device described in step one is arranged at the upper part of the combustion-aiding cylinder, the second microwave generating device is arranged at the lower part of the combustion-aiding cylinder, the first rotary feeding valve described in step two is arranged at the upper end of the combustion-aiding cylinder, the second rotary feeding valve is arranged at the lower end of the combustion-aiding cylinder, the upper end of the first rotary feeding valve is connected to a feed hopper, the lower end of the second rotary feeding valve is connected to a biomass boiler, a microwave combustion-aiding chamber is formed in the combustion-aiding cylinder, and the second humidity sensor described in step three is arranged at the lower part of the combustion-aiding cylinder;

[0014] A first temperature sensor, a first humidity sensor and a first air outlet are provided at the upper part of the combustion-supporting tube, and the first air outlet is connected to a first fan. A second temperature sensor and a second air outlet are also provided at the lower part of the combustion-supporting tube, and the second air outlet is connected to a second fan. The first microwave generating device and the second microwave generating device both include a plurality of waveguides and a plurality of magnetrons, and the plurality of magnetrons are connected to the combustion-supporting tube through one-to-one corresponding waveguides.

[0015] An integrated controller is arranged on the combustion-supporting tube, and the first temperature sensor, the second temperature sensor, the first humidity sensor, the second humidity sensor and the plurality of magnetrons are electrically connected to the integrated controller respectively.

[0016] Furthermore, the upper end of the combustion-aiding tube is tilted to the left, the several magnetrons of the first microwave generating device are composed of a first magnetron, a third magnetron and a fifth magnetron, the several waveguides of the first microwave generating device are composed of a first metal waveguide, a third metal waveguide and a fifth metal waveguide, the first magnetron is arranged on the right side wall of the combustion-aiding tube through the first metal waveguide, the fifth magnetron is arranged on the front side wall of the combustion-aiding tube through the fifth metal waveguide, the third magnetron is arranged on the rear side wall of the combustion-aiding tube through the third metal waveguide, and the first magnetron, the third magnetron and the fifth magnetron are electrically connected to the integrated controller respectively.

[0017] Furthermore, the several magnetrons of the second microwave generating device are composed of a second magnetron, a fourth magnetron and a sixth magnetron, the several waveguides of the second microwave generating device are composed of a second metal waveguide, a fourth metal waveguide and a sixth metal waveguide, the second magnetron is arranged on the right side wall of the combustion-aiding tube through the second metal waveguide, the fourth magnetron is arranged on the rear side wall of the combustion-aiding tube through the fourth metal waveguide, the sixth magnetron is arranged on the front side wall of the combustion-aiding tube through the sixth metal waveguide, and the second magnetron, the fourth magnetron and the sixth magnetron are electrically connected to the integrated controller respectively.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] After drying, the biomass shaped fuel becomes loose after the water is precipitated, which is conducive to the heat and mass transfer during the combustion process. The discharge port can be directly connected to the feed port of the biomass boiler. The biomass shaped fuel after the temperature rises and the water is separated enters the biomass boiler through the discharge port for combustion. The biomass shaped fuel after microwave treatment has low moisture content and high looseness, and the temperature is high after drying, which promotes the combustion in the boiler. The present invention separates the drying process of the biomass shaped fuel from the combustion process in the boiler, which can promote the combustion process of the fuel in the boiler and reduce the energy consumption of the boiler in the preheating stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front view of the dry biomass briquette fuel of the present invention;

[0021] Figure 2 It is a left view of the dry biomass briquette fuel of the present invention;

[0022] Figure 3 It is a top view of the dry biomass molded fuel of the present invention.

[0023] In the figure, 1. the first rotary feeding valve, 2. the first metal waveguide, 3. the first magnetron, 4. the first temperature sensor, 5. the first humidity sensor, 6. the first fan, 7. the combustion-aiding tube, 8. the second metal waveguide, 9. the second magnetron, 10. the second temperature sensor, 11. the second humidity sensor, 12. the second fan, 13. the second rotary feeding valve, 14. the fourth magnetron, 15. the fourth metal waveguide, 16. the integrated controller, 17. the third magnetron, 18. the third metal waveguide, 19. the fifth metal waveguide, 20. the fifth magnetron, 21. the sixth metal waveguide, 22. the sixth magnetron. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0025] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as bolt connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can be found in the existing connection methods to achieve the function, and those skilled in the art can choose according to their needs. For example: welding connection is selected for fixed connection, and bolt connection is selected for detachable connection.

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings. The following embodiments are provided to explain the present invention, but the present invention is not limited to the following embodiments.

[0027] Embodiment 1: Figure 1 to Figure 3 As shown, a microwave drying-activation-combustion-supporting method for biomass pellet fuel comprises the following steps:

[0028] Step 1: Detect the humidity of the biomass briquette fuel to be burned, and preliminarily adjust the power of each magnetron of the first microwave generating device and the second microwave generating device according to the humidity data obtained by the detection;

[0029] Step 2: close the second rotary feeding valve 13, start the first rotary feeding valve 1, put the biomass molding fuel into the feeding hopper, the biomass molding fuel fills the microwave combustion-supporting chamber through the first rotary feeding valve 1, start all the magnetrons on the first microwave generating device and the second microwave generating device, and the magnetrons emit microwaves to heat and dry the biomass molding fuel;

[0030] Step 3: When the humidity data collected by the second humidity sensor 11 meets the feeding requirements of the biomass boiler, the second rotary feeding valve 13 is started to allow the biomass briquette fuel that has completed drying, activation and combustion to enter the biomass boiler;

[0031] Step 4: Set the rotation speeds of the first rotary feeding valve 1 and the second rotary feeding valve 13 so that the feed amount and the discharge amount of the combustion-supporting cylinder 7 are equal;

[0032] Step 5: adjusting the power of several magnetrons of the second microwave generating device so that the humidity data collected by the second humidity sensor 11 is kept within the feed humidity range of the biomass boiler;

[0033] Step 6: After adjusting the powers of the magnetrons of the second microwave generator, if the humidity data collected by the second humidity sensor 11 still exceeds the feed humidity range of the biomass boiler, the powers of the magnetrons of the first microwave generator are further adjusted to keep the humidity data collected by the second humidity sensor 11 within the feed humidity range of the biomass boiler;

[0034] Step 7. Repeat steps 4 to 6 until the rotation speeds of the first rotary feeding valve 1 and the second rotary feeding valve 13 remain constant, the powers of the magnetrons of the first microwave generating device and the second microwave generating device are constant, and the humidity data collected by the second humidity sensor 11 remains within the feed humidity range of the biomass boiler, thereby achieving continuous feeding of the biomass molded fuel.

[0035] It includes a combustion-supporting tube 7, the first microwave generating device described in step one is arranged at the upper part of the combustion-supporting tube 7, the second microwave generating device is arranged at the lower part of the combustion-supporting tube 7, the first rotary feeding valve 1 described in step two is arranged at the upper end of the combustion-supporting tube 7, the second rotary feeding valve 13 is arranged at the lower end of the combustion-supporting tube 7, the upper end of the first rotary feeding valve 1 is connected to a feed hopper, the lower end of the second rotary feeding valve 13 is connected to a biomass boiler, a microwave combustion-supporting chamber is formed in the combustion-supporting tube 7, and the second humidity sensor 11 described in step three is arranged at the lower part of the combustion-supporting tube 7;

[0036] A first temperature sensor 4, a first humidity sensor 5 and a first air outlet are provided at the upper part of the combustion-supporting tube 7, and the first air outlet is connected to the first fan 6. A second temperature sensor 10 and a second air outlet are also provided at the lower part of the combustion-supporting tube 7, and the second air outlet is connected to the second fan 12. The first microwave generating device and the second microwave generating device both include a plurality of waveguides and a plurality of magnetrons, and the plurality of magnetrons are connected to the combustion-supporting tube 7 through one-to-one corresponding waveguides.

[0037] An integrated controller 16 is provided on the combustion-supporting tube 7 , and the first temperature sensor 4 , the second temperature sensor 10 , the first humidity sensor 5 , the second humidity sensor 11 and the plurality of magnetrons are electrically connected to the integrated controller 16 , respectively.

[0038] The upper end of the combustion-aiding tube 7 is tilted to the left, and the multiple magnetrons of the first microwave generating device are composed of a first magnetron 3, a third magnetron 17 and a fifth magnetron 20. The multiple waveguides of the first microwave generating device are composed of a first metal waveguide 2, a third metal waveguide 18 and a fifth metal waveguide 19. The first magnetron 3 is arranged on the right side wall of the combustion-aiding tube 7 through the first metal waveguide 2, the fifth magnetron 20 is arranged on the front side wall of the combustion-aiding tube 7 through the fifth metal waveguide 19, and the third magnetron 17 is arranged on the rear side wall of the combustion-aiding tube 7 through the third metal waveguide 18. The first magnetron 3, the third magnetron 17 and the fifth magnetron 20 are electrically connected to the integrated controller 16 respectively.

[0039] The several magnetrons of the second microwave generating device are composed of a second magnetron 9, a fourth magnetron 14 and a sixth magnetron 22, and the several waveguides of the second microwave generating device are composed of a second metal waveguide 8, a fourth metal waveguide 15 and a sixth metal waveguide 21. The second magnetron 9 is arranged on the right side wall of the combustion-aiding tube 7 through the second metal waveguide 8, the fourth magnetron 14 is arranged on the rear side wall of the combustion-aiding tube 7 through the fourth metal waveguide 15, and the sixth magnetron 22 is arranged on the front side wall of the combustion-aiding tube 7 through the sixth metal waveguide 21. The second magnetron 9, the fourth magnetron 14 and the sixth magnetron 22 are electrically connected to the integrated controller 16 respectively.

[0040] The biomass molding fuel enters the microwave combustion chamber through the first rotary feeding valve 1. The first microwave generator and the second microwave generator can both emit microwaves to heat and dry the biomass molding fuel. During the drying process, the moisture in the biomass molding fuel is precipitated, and the precipitated moisture is discharged from the microwave combustion chamber through the first fan 6 and the second fan 12. The first temperature sensor 4 is used to monitor the temperature of the upper part of the microwave combustion chamber. The feedback signal of the first temperature sensor 4 controls the power of the first magnetron 3 through the integrated controller 16. The second temperature sensor 10 is used to monitor the temperature of the lower part of the microwave combustion chamber. The feedback signal of the second temperature sensor 10 controls the power of the second magnetron 9 through the integrated controller 16. The first humidity sensor 6 is used to monitor the humidity of the upper part of the microwave combustion chamber. The second humidity sensor 11 is used to monitor the humidity of the lower part of the microwave combustion chamber. When the collected humidity signal reaches the set range, the discharge port 13 can be opened to allow the biomass molding fuel to slide out of the device. The first microwave generator and the second microwave generator work together to achieve the best drying effect and realize continuous drying output of the biomass molding fuel.

[0041] After drying, the biomass shaped fuel becomes loose after the water is precipitated, which is conducive to the heat and mass transfer during the combustion process. The discharge port 13 can be directly connected to the feed port of the biomass boiler. The biomass shaped fuel with increased temperature and water precipitated enters the biomass boiler through the discharge port 13 for combustion. The biomass shaped fuel after microwave treatment has low moisture content and high looseness, and the temperature is high after drying, which promotes the combustion in the boiler. The present invention separates the drying process of the biomass shaped fuel from the combustion process in the boiler, which can promote the combustion process of the fuel in the boiler and reduce the energy consumption of the boiler in the preheating stage.

[0042] The above embodiments are merely exemplary descriptions of the present invention and do not limit its protection scope. Those skilled in the art may also make partial changes thereto, which are within the protection scope of the present invention as long as they do not exceed the spirit of the present invention.

Claims

1. A microwave drying-activation-combustion-supporting method for biomass briquette fuel, characterized in that: The following steps are involved: Step 1: Detect the humidity of the biomass briquette fuel to be burned, and preliminarily adjust the power of each magnetron of the first microwave generating device and the second microwave generating device according to the humidity data obtained by the detection; Step 2: close the second rotary feeding valve (13), start the first rotary feeding valve (1), put the biomass molding fuel into the feeding hopper, the biomass molding fuel fills the microwave combustion-supporting chamber through the first rotary feeding valve (1), start all the magnetrons on the first microwave generating device and the second microwave generating device, and the magnetrons emit microwaves to heat and dry the biomass molding fuel; Step 3: When the humidity data collected by the second humidity sensor (11) meets the feeding requirements of the biomass boiler, the second rotary feeding valve (13) is started to allow the biomass shaped fuel that has completed drying, activation and combustion to enter the biomass boiler; Step 4: setting the rotation speeds of the first rotary feed valve (1) and the second rotary feed valve (13) so that the feed amount and the discharge amount of the combustion-supporting cylinder (7) are equal; Step 5: adjusting the power of the magnetrons of the second microwave generating device so that the humidity data collected by the second humidity sensor (11) remains within the feed humidity range of the biomass boiler; Step 6: When the humidity data collected by the second humidity sensor (11) still exceeds the feed humidity range of the biomass boiler after adjusting the powers of the magnetrons of the second microwave generating device, the powers of the magnetrons of the first microwave generating device are further adjusted so that the humidity data collected by the second humidity sensor (11) remains within the feed humidity range of the biomass boiler; Step 7, repeating steps 4 to 6 until the rotation speeds of the first rotary feeding valve (1) and the second rotary feeding valve (13) remain constant, the powers of the magnetrons of the first microwave generating device and the second microwave generating device remain constant, and the humidity data collected by the second humidity sensor (11) remains within the feed humidity range of the biomass boiler, thereby achieving continuous feeding of the biomass pelletized fuel.

2. The microwave drying-activation-combustion-supporting method for biomass briquette fuel according to claim 1, characterized in that: It comprises a combustion-supporting cylinder (7), wherein the first microwave generating device described in step one is arranged at the upper part of the combustion-supporting cylinder (7), and the second microwave generating device is arranged at the lower part of the combustion-supporting cylinder (7), the first rotary feeding valve (1) described in step two is arranged at the upper end of the combustion-supporting cylinder (7), and the second rotary feeding valve (13) is arranged at the lower end of the combustion-supporting cylinder (7), the upper end of the first rotary feeding valve (1) is connected to a feed hopper, and the lower end of the second rotary feeding valve (13) is connected to a biomass boiler, a microwave combustion-supporting chamber is formed in the combustion-supporting cylinder (7), and the second humidity sensor (11) described in step three is arranged at the lower part of the combustion-supporting cylinder (7); A first temperature sensor (4), a first humidity sensor (5) and a first air outlet are provided at the upper portion of the combustion-supporting tube (7), the first air outlet being connected to a first fan (6), a second temperature sensor (10) and a second air outlet are provided at the lower portion of the combustion-supporting tube (7), the second air outlet being connected to a second fan (12), the first microwave generating device and the second microwave generating device both comprising a plurality of waveguides and a plurality of magnetrons, the plurality of magnetrons being connected to the combustion-supporting tube (7) via one-to-one corresponding waveguides; An integrated controller (16) is provided on the combustion-supporting cylinder (7), and the first temperature sensor (4), the second temperature sensor (10), the first humidity sensor (5), the second humidity sensor (11) and the plurality of magnetrons are electrically connected to the integrated controller (16) respectively.

3. The microwave drying-activation-combustion-supporting method for biomass briquette fuel according to claim 2, characterized in that: The upper end of the combustion-aiding tube (7) is arranged to be tilted to the left. The plurality of magnetrons of the first microwave generating device are composed of a first magnetron (3), a third magnetron (17) and a fifth magnetron (20). The plurality of waveguides of the first microwave generating device are composed of a first metal waveguide (2), a third metal waveguide (18) and a fifth metal waveguide (19). The first magnetron (3) is arranged on the right side wall of the combustion-aiding tube (7) through the first metal waveguide (2). The fifth magnetron (20) is arranged on the front side wall of the combustion-aiding tube (7) through the fifth metal waveguide (19). The third magnetron (17) is arranged on the rear side wall of the combustion-aiding tube (7) through the third metal waveguide (18). The first magnetron (3), the third magnetron (17) and the fifth magnetron (20) are respectively electrically connected to the integrated controller (16).

4. The microwave drying-activation-combustion-supporting method for biomass briquette fuel according to claim 3, characterized in that: The plurality of magnetrons of the second microwave generating device are composed of a second magnetron (9), a fourth magnetron (14) and a sixth magnetron (22); the plurality of waveguides of the second microwave generating device are composed of a second metal waveguide (8), a fourth metal waveguide (15) and a sixth metal waveguide (21); the second magnetron (9) is arranged on the right side wall of the combustion-aiding cylinder (7) through the second metal waveguide (8); the fourth magnetron (14) is arranged on the rear side wall of the combustion-aiding cylinder (7) through the fourth metal waveguide (15); the sixth magnetron (22) is arranged on the front side wall of the combustion-aiding cylinder (7) through the sixth metal waveguide (21); and the second magnetron (9), the fourth magnetron (14) and the sixth magnetron (22) are respectively electrically connected to an integrated controller (16).

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