Biomass boiler fuel drying system

Abstract

The invention relates to the technical field of biomass fuel drying, in particular to a biomass boiler fuel drying system. Comprising a first-stage drying device, a smoke outlet of the first-stage drying device is connected with a dust treatment system through a pipeline, a gas outlet of the dust treatment system is connected with a dehumidification device through a pipeline, and a gas outlet of the dehumidification device is connected with a second-stage drying device through a pipeline. And a gas outlet of the secondary drying device is connected with the filtering device. According to the biomass fuel drying system, biomass fuel is dried through the first-stage drying device and the second-stage drying device, waste smoke dried by the first-stage drying device is subjected to dust removal through the dust treatment system and then enters the dehumidification device to be dehumidified, and dried clean gas is obtained; clean gas enters the second-stage drying device to dry biomass fuel, the biomass fuel is discharged after being filtered by the filtering device, high-temperature flue gas waste heat discharged by the first-stage drying device is recycled, and pollution is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of biomass fuel drying, and in particular to a biomass boiler fuel drying system. Background Art

[0002] Biomass fuel mainly includes various straws, wood and agricultural and forestry wastes. Fresh biomass has a high moisture content, and high fuel moisture content will cause great harm to biomass storage, boiler feeding system and combustion system. Therefore, biomass needs to be dried. Drying is a high energy consumption industry. How to dry biomass in an energy-saving and economical way is an important issue in the utilization of biomass energy.

[0003] In the prior art, direct contact drying devices are conventionally used to dry biomass fuels, but the waste heat after drying is directly discharged into the air, the exhaust heat is not effectively utilized, and the exhaust gas may produce emissions, including particulate matter, dust, etc. Therefore, the present invention is proposed. Summary of the invention

[0004] The object of the present invention is to provide a biomass boiler fuel drying system, which can recycle the waste heat after the biomass fuel is dried and reduce the emission of pollutants.

[0005] The present invention provides a biomass boiler fuel drying system, comprising a primary drying device, wherein the smoke outlet of the primary drying device is connected to a dust treatment system through a pipeline, the gas outlet of the dust treatment system is connected to a dehumidification device through a pipeline, the gas outlet of the dehumidification device is connected to a secondary drying device through a pipeline, and the gas outlet of the secondary drying device is connected to a filtering device.

[0006] Furthermore, the primary drying device includes an inner cylinder and an outer cylinder, a drying chamber is formed between the inner cylinder and the outer cylinder, the smoke inlet of the drying chamber is connected to the high-temperature smoke pipe, and the smoke outlet of the drying chamber is connected to the dust treatment system through a pipe.

[0007] Furthermore, the dust handling system includes a cyclone separator and a dust collector, the smoke inlet of the cyclone separator is connected to the smoke outlet of the primary drying device through a pipeline, and the smoke outlet of the cyclone separator is connected to the gas inlet of the dust collector through a pipeline.

[0008] Furthermore, a dust collecting box is provided at the dust outlet of the cyclone separator.

[0009] Furthermore, the dust collector is a bag dust collector.

[0010] Furthermore, the dehumidification device includes a box body, and an exhaust device, a heating device and a condensing device are arranged inside the box body. The air inlet of the exhaust device is connected to the gas outlet of the dust collector through a pipe, the air outlet of the exhaust device is connected to the heating pipe, the heating pipe is connected to the condensing device, and the heating device is arranged on the heating pipe.

[0011] Furthermore, the gas outlet of the dehumidification device is connected to the reheating device through a pipeline, and the gas outlet of the reheating device is connected to the secondary drying device through a pipeline.

[0012] Furthermore, a dust detector is provided at the gas outlet of the dust collector; a control valve is provided on the pipeline connecting the dust collector and the dehumidification device, the gas outlet of the dust collector is also connected to the induced draft fan through a pipeline, and the outlet of the induced draft fan is connected to the flue gas inlet of the cyclone separation through a pipeline.

[0013] Furthermore, a temperature and humidity sensor is provided at the gas outlet of the dehumidification device.

[0014] Furthermore, a desulfurization and denitrification system is provided between the primary drying device and the dust treatment system, the flue gas inlet of the desulfurization and denitrification system is connected to the flue gas outlet of the primary drying device through a pipeline, and the flue gas outlet of the desulfurization and denitrification system is connected to the dust treatment system through a pipeline.

[0015] In summary, compared with the prior art, the present invention has the following advantages:

[0016] The technical solution provided by the present invention dries the biomass fuel by setting up a primary drying device and a secondary drying device, wherein the waste flue gas dried by the primary drying device is dedusted by a dust treatment system and then enters a dehumidification device for dehumidification to obtain dry clean gas, the clean gas enters the secondary drying device to dry the biomass fuel, and finally is discharged after being filtered by a filtering device, and the waste heat of the high-temperature flue gas discharged by the primary drying device is recycled to reduce pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the structure of a drying system in Example 1 of the present invention;

[0019] Figure 2This is a schematic diagram of the structure of the dehumidification device in Example 1 of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the drying system in Example 2 of the present invention.

[0021] Explanation of the reference numerals: 1-primary drying device; 2-cyclone separator; 3-dust collector; 4-dehumidification device; 401-box; 402-exhaust device; 403-heating device; 404-condensing device; 405-drying gas pipeline; 406-three-way control valve; 407-branch pipe; 5-reheating device; 6-secondary drying device; 7-filtering device; 8-desulfurization equipment; 9-denitrification equipment; 10-dust detector; 11-induced draft fan. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" 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 a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. 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.

[0025] Example 1

[0026] A biomass boiler fuel drying system, such as Figure 1 As shown, it includes a primary drying device 1, the smoke outlet of the primary drying device 1 is connected to the dust treatment system through a pipeline, the gas outlet of the dust treatment system is connected to the dehumidification device 4 through a pipeline, the gas outlet of the dehumidification device 4 is connected to the secondary drying device 6 through a pipeline, and the gas outlet of the secondary drying device 6 is connected to the filtering device 7. Both the primary drying device 1 and the secondary drying device 6 are devices for drying biomass fuel.

[0027] The primary drying device 1 and the secondary drying device 6 in this embodiment are both conventional biomass fuel drying devices in the art, and both include an inner cylinder and an outer cylinder, and a drying chamber is formed between the inner cylinder and the outer cylinder. The smoke inlet of the drying chamber of the primary drying device 1 is connected to a high-temperature smoke pipe, and the biomass fuel is dried using high-temperature boiler smoke, and the smoke outlet of the drying chamber is connected to a dust treatment system through a pipe.

[0028] The dust treatment system includes a cyclone separator 2 and a dust collector 3. The smoke inlet of the cyclone separator 2 is connected to the smoke outlet of the drying chamber of the primary drying device 1 through a pipeline, and the smoke outlet of the cyclone separator 2 is connected to the gas inlet of the dust collector 3 through a pipeline. A dust collecting box is provided at the dust outlet of the cyclone separator 2 to facilitate the collection and treatment of the treated dust. The dust collector 3 adopts a bag dust collector. The cyclone separator 2 uses centrifugal force to separate most of the large dust particles in the flue gas cooled after drying. After the dust-containing gas enters the cyclone separator 2, due to the centrifugal force formed by high-speed rotation, the heavier dust particles are thrown to the wall of the device, and fall into the dust collecting box through the dust outlet, and the waste flue gas is initially dusted, and then enters the bag dust collector to further remove fine dust particles to ensure that the discharged gas is cleaner.

[0029] like Figure 2 As shown, the dehumidification device 4 includes a box body 401, and an exhaust device 402, a heating device 403 and a condensing device 404 are arranged inside the box body 401. The side wall of the box body 401 is provided with a wet gas inlet and a dry gas outlet. The exhaust device 402 adopts an exhaust fan, and the air inlet of the exhaust fan is connected to the wet gas inlet. The air outlet of the exhaust fan is connected to the heating pipe. The heating device 403 is arranged on the heating pipe. The heating device 403 can be installed inside the heating pipe. The heating device 403 in this embodiment can adopt an electric heater. The outlet of the heating pipe is connected to the condensing device 404. The condensing device 404 can adopt the condenser in the conventional dehumidifier in the prior art. The outlet of the condensing device 404 is connected to the dry gas outlet. The wet gas treated by the dust treatment system is introduced into the dehumidification device 4 through the exhaust device 402, and the gas is heated by the heating device 403, and then the heated gas is separated from water and steam by the condensing device 404 to obtain dry gas.

[0030] A dry gas pipeline 405 is installed at the dry gas outlet of the box 401, and the dry gas pipeline 405 is also connected to the wet gas inlet through a branch pipe 407. A three-way control valve 406 is installed on the dry gas pipeline 405, and the branch pipe 407 is connected to the three-way control valve 406. A temperature and humidity sensor is installed inside the dry gas pipeline 405 to detect the temperature and humidity of the dehumidified dry gas. When the gas humidity detected by the temperature and humidity sensor does not meet the use requirements, the gas enters the box 401 through the branch pipe 407 and the wet gas inlet for dehumidification again. After meeting the requirements, the three-way control valve 406 is opened to enter the next step of operation.

[0031] The smoke inlet of the drying chamber of the secondary drying device 6 is connected to the dry gas pipeline 405 of the dehumidification device 4. The dry gas after dehumidification directly enters the drying chamber of the secondary drying device 6. A reheating device 5 is installed on the dry gas pipeline 405 after the three-way control valve 406. The temperature of the dried gas is detected by a temperature and humidity sensor. When the temperature of the dried gas is low, the reheating device 5 is turned on to heat the gas before the gas enters the secondary drying device 6 to dry the biomass fuel. When the temperature of the dried gas is still maintained at a relatively high temperature, the reheating device 5 does not need to be turned on, and the gas can directly enter the secondary drying device 6.

[0032] A filter device 7 is installed at the gas outlet of the secondary drying device 6. The filter device 7 can use a conventional gas filter in the art. The secondary drying device 6 directly uses clean gas after dust removal and dehumidification for drying, and the dried gas can be discharged after simple filtering.

[0033] The working process of the biomass boiler fuel drying system provided in this embodiment is as follows: when in use, the biomass fuel to be dried is added to the primary drying device 1 and the secondary drying device 6 respectively, and the high-temperature flue gas is passed into the primary drying device 1, and the biomass fuel is dried by the high-temperature flue gas. The flue gas with reduced temperature after drying enters the cyclone separator 2 and the dust collector 3 for dust removal to obtain clean gas, and the clean gas enters the dehumidifier 4 for dehumidification to obtain dry clean gas, which is detected by the temperature and humidity sensor inside the dry gas pipeline 405. When the humidity does not meet the requirements, it returns to the dehumidifier 4 for dehumidification again. When the temperature does not meet the requirements, the reheating device 5 is started for heating. After the temperature and humidity meet the requirements, it directly enters the secondary drying device 6 to dry the biomass fuel, and the dried gas is directly discharged after being filtered by the filter device 7.

[0034] Example 2

[0035] A biomass boiler fuel drying system, the technical solution in this embodiment is basically the same as that in embodiment 1, such as Figure 3 As shown, the differences are: (1) a dust detector 10 and a control valve are provided on the pipeline connecting the dust collector 3 and the dehumidification device 4 in this embodiment, the gas outlet of the dust collector 3 is connected through a pipeline induced draft fan 11, and the outlet of the induced draft fan 11 is connected to the flue gas inlet of the cyclone separator 2 through a pipeline; (2) the structure of the filtering device 7 is different; (3) a desulfurization and denitrification system is also provided in this embodiment.

[0036] A dust detector 10 is provided to detect the dust concentration of the treated gas. When the detected dust concentration of the gas is low, the gas can directly enter the dehumidification device 4. When the dust concentration of the gas is high, the control valve is closed to allow the gas to pass through the induced draft fan 11 and enter the cyclone separator 2 again for dust removal until it meets the requirements.

[0037] The filter device 7 in this embodiment includes a housing, and an air inlet and an air outlet are respectively arranged on two opposite side walls of the housing, the air inlet is connected to the gas outlet of the secondary drying device 6, and a primary filter and a high-efficiency filter are arranged inside the housing. After being processed by the primary filter and the high-efficiency filter, the discharged gas is cleaner and more environmentally friendly.

[0038] The flue gas inlet of the desulfurization and denitrification system is connected to the flue gas outlet of the primary drying device 1 through a pipeline, and the flue gas outlet of the desulfurization and denitrification system is connected to the flue gas inlet of the cyclone separator 2 through a pipeline, and valves are respectively provided on the connected pipelines, and valves are also provided on the pipeline connecting the primary drying device 1 and the cyclone separator 2. The set desulfurization and denitrification system can desulfurize and denitrify the high-temperature flue gas used. The primary drying device 1 can use high-temperature flue gas emitted by a variety of equipment, some of which emit high-temperature flue gas containing not only particulate matter and dust, but also sulfur dioxide and nitrogen oxides. The set desulfurization and denitrification system can process the sulfur dioxide and nitrogen oxides contained in the flue gas.

[0039] A flue gas detector is installed at the flue gas outlet of the primary drying device 1 to detect sulfur dioxide and nitrogen oxides in the flue gas discharged from the primary drying device 1. When the concentrations of sulfur dioxide and nitrogen oxides are detected to be high, the discharged flue gas is allowed to enter the desulfurization and denitrification system through a control valve and then enter the cyclone separator 2 after desulfurization and denitrification treatment; when the concentrations of sulfur dioxide and nitrogen oxides are detected to be low, the flue gas is directly transported to the cyclone separator 2 through a control valve.

[0040] The desulfurization and denitrification system in this embodiment includes a desulfurization device 8 and a denitrification device 9. The desulfurization device 8 adopts an activated carbon adsorption tower, and the denitrification device 9 adopts an SCR denitrification reactor. The activated carbon adsorption tower is filled with activated carbon, and the side wall of the activated carbon adsorption tower is provided with a flue gas inlet and a flue gas outlet. The flue gas inlet is connected to the flue gas outlet of the primary drying device 1 through a pipeline, and the flue gas outlet is connected to the flue gas inlet of the SCR denitrification reactor; the SCR denitrification reactor is a reactor based on an ammonia catalytic reduction method. The SCR denitrification reactor is provided with a flue gas inlet and a flue gas outlet, and is also provided with an ammonia inlet. The flue gas outlet is connected to the flue gas inlet of the cyclone separator 2 through a pipeline. The ammonia and the flue gas coming out of the activated carbon adsorption tower undergo a denitrification reaction in the SCR denitrification reactor to remove nitrogen oxides in the flue gas, and then enter the cyclone separator 2.

[0041] The biomass boiler fuel drying system provided by the present invention removes dust and dehumidifies the flue gas discharged from the primary drying device through the dust treatment system and the dehumidification device, and obtains dry and clean gas, which enters the secondary drying device to dry the biomass fuel. After drying, it can be discharged after simple filtration, and the heat of the waste flue gas discharged from the primary drying device is recycled. The discharged gas does not contain dust and particulate matter, which is more environmentally friendly.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A biomass boiler fuel drying system, characterized in that: The invention comprises a primary drying device (1), wherein the smoke outlet of the primary drying device (1) is connected to a dust treatment system via a pipeline, the gas outlet of the dust treatment system is connected to a dehumidification device (4) via a pipeline, the gas outlet of the dehumidification device (4) is connected to a secondary drying device (6) via a pipeline, and the gas outlet of the secondary drying device (6) is connected to a filtering device (7).

2. The biomass boiler fuel drying system according to claim 1, characterized in that: The primary drying device (1) comprises an inner cylinder and an outer cylinder, a drying chamber is formed between the inner cylinder and the outer cylinder, a smoke inlet of the drying chamber is connected to a high-temperature smoke pipe, and a smoke outlet of the drying chamber is connected to the dust treatment system via a pipe.

3. The biomass boiler fuel drying system according to claim 2, characterized in that: The dust treatment system comprises a cyclone separator (2) and a dust collector (3), wherein the smoke inlet of the cyclone separator (2) is connected to the smoke outlet of the primary drying device (1) via a pipeline, and the smoke outlet of the cyclone separator (2) is connected to the gas inlet of the dust collector (3) via a pipeline.

4. The biomass boiler fuel drying system according to claim 3, characterized in that: A dust collecting box is provided at the dust outlet of the cyclone separator (2).

5. The biomass boiler fuel drying system according to claim 3, characterized in that: The dust collector (3) is a bag dust collector.

6. The biomass boiler fuel drying system according to claim 3, characterized in that: The dehumidification device (4) comprises a box body (401), wherein an exhaust device (402), a heating device (403) and a condensing device (404) are arranged inside the box body (401), the air inlet of the exhaust device (402) is connected to the gas outlet of the dust collector (3) through a pipeline, the air outlet of the exhaust device (402) is connected to the heating pipeline, the heating pipeline is connected to the condensing device (404), and the heating pipeline is provided with the heating device (403).

7. The biomass boiler fuel drying system according to claim 6, characterized in that: The gas outlet of the dehumidification device (4) is connected to the reheating device (5) through a pipeline, and the gas outlet of the reheating device (5) is connected to the secondary drying device (6) through a pipeline.

8. The biomass boiler fuel drying system according to claim 6, characterized in that: A dust detector (10) is provided at the gas outlet of the dust collector (3); a control valve is provided on the pipeline connecting the dust collector (3) and the dehumidification device (4); the gas outlet of the dust collector (3) is also connected to an induced draft fan (11) via a pipeline; and the outlet of the induced draft fan (11) is connected to the smoke inlet of the cyclone separator (2) via a pipeline.

9. The biomass boiler fuel drying system according to claim 7, characterized in that: A temperature and humidity sensor is provided at the gas outlet of the dehumidification device (4).

10. The biomass boiler fuel drying system according to claim 1, characterized in that: A desulfurization and denitrification system is provided between the primary drying device (1) and the dust treatment system. The flue gas inlet of the desulfurization and denitrification system is connected to the flue gas outlet of the primary drying device (1) via a pipeline, and the flue gas outlet of the desulfurization and denitrification system is connected to the dust treatment system via a pipeline.

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