Coal grinding and drying system

Abstract

The utility model discloses a coal grinding and drying system which at least comprises at least one gas input pipeline, the inert gas generator is connected with the gas input pipeline; the coal mill is connected with an outlet of the inert gas generator; the filter is connected with an outlet of the coal mill; the input end of the emptying pipeline is connected to the outlet of the filter; and the backflow pipeline is arranged in parallel with the emptying pipeline, the input end of the backflow pipeline is connected to the outlet of the filter, the backflow pipeline comprises a first branch line and a second branch line, the output end of the first branch line is connected with the inert gas generator, and the output end of the second branch line is connected to the gas input pipeline. According to the pulverized coal drying system provided by the utility model, the content of nitrogen oxides in exhausted gas can be reduced, and the harm of the system to the environment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of coal chemical industry, in particular to a coal grinding and drying system. Background Art

[0002] As an important part of coal chemical equipment, the coal grinding and drying system directly determines whether the coal chemical equipment can operate safely, stably and efficiently. While the coal grinding and drying system outputs pulverized coal, it also discharges gas into the environment to remove moisture in the coal grinding and drying system and reduce the water content in the pulverized coal. However, in the existing coal grinding and drying system, the nitrogen oxide content in the discharged gas is high, which exceeds the environmental emission requirements. Utility Model Content

[0003] The utility model aims to provide a coal grinding and drying system, which can reduce the nitrogen oxide content in the exhaust gas, make the nitrogen oxide content in the exhaust gas meet the environmental emission requirements, and reduce the harm of the system to the environment.

[0004] In order to achieve the above-mentioned purpose and other related purposes, the utility model is implemented through the following technical solutions.

[0005] The utility model provides a coal grinding and drying system, which at least comprises:

[0006] at least one gas input line;

[0007] an inert gas generator connected to the gas input pipeline;

[0008] a coal mill connected to an outlet of the inert gas generator;

[0009] A filter connected to the outlet of the coal mill;

[0010] an exhaust line having an input end connected to an outlet of the filter; and

[0011] A reflux pipeline is arranged in parallel with the exhaust pipeline, the input end of the reflux pipeline is connected to the outlet of the filter, and the reflux pipeline includes a first branch line and a second branch line, the output end of the first branch line is connected to the inert gas generator, and the output end of the second branch line is connected to the gas input pipeline.

[0012] In an embodiment of the present invention, when there are multiple gas input pipelines, the multiple gas input pipelines are arranged in parallel.

[0013] In an embodiment of the present invention, the gas input pipeline includes a fuel gas input pipeline, an ambient air input pipeline and an inert gas input pipeline, and the output end of the second branch line is connected to the ambient air input pipeline.

[0014] In an embodiment of the present invention, the coal grinding and drying system further comprises an air blower, and the air blower is disposed on the ambient air input pipeline.

[0015] In an embodiment of the present invention, the coal grinding and drying system further comprises at least one inlet valve, and the inlet valve is arranged on the second branch line.

[0016] In an embodiment of the present invention, the coal grinding and drying system further comprises at least one flow meter, and the flow meter is arranged on the second branch line on one side of the inlet valve.

[0017] In an embodiment of the present invention, the coal grinding and drying system further comprises at least one regulating valve, and the regulating valve is arranged on the second branch line on a side of the flow meter away from the inlet valve.

[0018] In an embodiment of the utility model, the coal grinding and drying system further comprises a circulating flue gas induced draft fan, and the circulating flue gas induced draft fan is arranged on the second branch line on a side of the flow regulating valve away from the flow meter.

[0019] In an embodiment of the utility model, the coal grinding and drying system further comprises at least one outlet valve, and the outlet valve is arranged on the second branch line on the side of the circulating flue gas induced draft fan away from the regulating valve.

[0020] In an embodiment of the utility model, the coal grinding and drying system further comprises at least one one-way valve, and the one-way valve is arranged on the second branch line on the side of the outlet valve away from the circulating flue gas induced draft fan.

[0021] In summary, the utility model proposes a coal grinding and drying system that can output dry pulverized coal raw materials and ensure the safe, stable and efficient operation of downstream devices. Moreover, the coal grinding and drying system provided by the utility model can reduce the nitrogen oxide content in the exhaust gas, so that the nitrogen oxide content in the exhaust gas meets the environmental emission requirements and reduces the harm of the system to the environment.

[0022] Of course, any method of implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1It is a structural schematic diagram of a coal grinding and drying system in one embodiment of the utility model.

[0025] Marking Description:

[0026] 11. Gas input pipeline; 111. Fuel gas input pipeline; 112. Ambient air input pipeline; 113. Inert gas input pipeline; 12. Inert gas generator; 13. Coal pulverizer; 14. Air blower; 15. Filter; 16. Circulating fan; 17. Exhaust pipeline; 18. Return pipeline; 181. First branch line; 182. Second branch line; 19. Control valve; 20. Analyzer; 21. Inlet valve; 22. Flow meter; 23. Regulating valve; 24. Circulating flue gas induced draft fan; 25. Outlet valve; 26. Check valve. DETAILED DESCRIPTION

[0027] The following describes the implementation of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations. The details in the present invention can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0029] In the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does 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 a limitation on the present application. In addition, if the terms "first" and "second" appear, they are only used for description and distinction purposes, and cannot be understood as indicating or implying relative importance.

[0030] The coal grinding and drying system outputs dry pulverized coal to the gasifier, thus achieving smooth operation of the coal gasification unit. In the early stage of the coal gasification unit operation, the load of the gasifier is low, and the load of the coal grinding and drying system is reduced accordingly. The content of nitrogen oxides in the gas discharged by the coal grinding and drying system is less than 40mg / m 3However, as the gasifier load increases, the load of the coal grinding and drying system also increases, and the heat load of the inert gas generator in the coal grinding and drying system also increases. The combustion temperature in the inert gas generator is high, which produces a large amount of nitrogen oxides, causing the nitrogen oxide content in the gas discharged from the coal grinding and drying system to exceed 40mg / m 3 , maintained at 70-80 mg / m 3 The coal grinding and drying system provided by the utility model can solve the problem of high nitrogen oxide content in the exhaust gas, and reduce the nitrogen oxide content in the exhaust gas from 70-80 mg / m 3 , down to 20-30 mg / m 3 , meet environmental emission requirements, thereby reducing the harm of the coal grinding and drying system to the environment.

[0031] See also Figure 1 As shown, the utility model provides a coal grinding and drying system, for example, including a gas input pipeline 11, an inert gas generator 12, a coal mill 13, a filter 15 and a return pipeline 18, etc., which are connected in sequence. Among them, the return pipeline 18, for example, includes a first branch line 181 and a second branch line 182, etc. The first branch line 181 is connected to the inert gas generator 12, and the second branch line 182 is connected to the gas input pipeline 11. The coal grinding and drying system provided by the utility model introduces part of the gas at the outlet of the filter 15 into the gas input pipeline 11 through the second branch line 182, and then enters the combustion chamber in the inert gas generator 12 together with the gas in the gas input pipeline 11, thereby reducing the temperature of the combustion chamber in the inert gas generator 12, reducing the generation of nitrogen oxides, and reducing the harm of the coal grinding and drying system to the environment.

[0032] See also Figure 1 As shown, in one embodiment of the utility model, the gas input pipeline 11 provides a gas source for the coal grinding drying system. Among them, the gas input pipeline 11 is, for example, at least one. When the gas input pipeline 11 is multiple, the gas input pipelines 11 are arranged in parallel. In this embodiment, the gas input pipelines 11 are, for example, three, and the three gas input pipelines 11 include, for example, a fuel gas input pipeline 111, an ambient air input pipeline 112, and an inert gas input pipeline 113. Among them, an air blower 14 is provided on the ambient air input pipeline 112, for example, to deliver ambient air of a preset flow rate and pressure to the subsequent device. In this embodiment, the inert gas input pipeline 113, for example, delivers an inert gas such as argon, and also delivers an inactive gas such as nitrogen.

[0033] See also Figure 1As shown, in one embodiment of the utility model, the inert gas generator 12 is connected to the gas input pipeline 11. In this embodiment, the fuel gas input pipeline 111 inputs the fuel gas, and the ambient air input pipeline 112 inputs the ambient air. The fuel gas and the ambient air are fully burned in the combustion chamber of the inert gas generator 12, and the combustion chamber outputs dry hot flue gas. The hot flue gas and the inert gas in the inert gas input pipeline 113 are mixed, and the dry hot inert gas is output at the outlet of the inert gas generator 12. Among them, the burning temperature of the fuel gas in the fuel gas input pipeline 111 is above 1000°C. By setting the inert gas input pipeline 113, the oxygen content in the gas at the outlet of the inert gas generator 12 can be further reduced, so that the outlet of the inert gas generator 12 can output safe hot inert gas, and use it as a heat source and atmosphere to grind and dry coal in subsequent operations, thereby improving the safety of the subsequent coal grinding process.

[0034] See also Figure 1 As shown, in one embodiment of the utility model, the coal mill 13 is connected to the outlet of the inert gas generator 12. In this embodiment, while the raw coal is ground into powder in the coal mill 13, the dry hot inert gas at the outlet of the inert gas generator 12 enters the coal mill 13, and the hot inert gas is used as a heat source to dry the coal in the coal mill 13, and the outlet of the coal mill 13 outputs a mixture of dry pulverized coal and inert gas. Among them, the hot inert gas entering the coal mill 13 dries the moisture in the raw coal, which consumes heat, and the temperature of the hot inert gas becomes lower. The temperature of the inert gas leaving the coal mill 13 is about 105°C. By introducing the dry hot inert gas at the outlet of the inert gas generator 12 into the coal mill 13, it is possible to prevent the explosion inside the coal mill 13 and improve the safety of the coal pulverizing process.

[0035] See also Figure 1 As shown, in one embodiment of the utility model, the filter 15 is connected to the outlet of the coal mill 13. In this embodiment, the mixture of pulverized coal and inert gas at the outlet of the coal mill 13 enters the filter 15, and the filter 15 separates the pulverized coal and sends it to the downstream device for processing or storage, while the remaining inert gas is sent to the subsequent device for reuse. Among them, the filter 15 is, for example, a bag filter.

[0036] See also Figure 1 As shown, in one embodiment of the utility model, the coal grinding and drying system further includes a circulating fan 16, which is connected to the outlet of the filter 15. By providing the circulating fan 16, the gas at the outlet of the filter 15 can be quickly extracted to the subsequent device.

[0037] See also Figure 1As shown, in one embodiment of the utility model, the coal pulverizing drying system further includes an exhaust pipeline 17, and the input end of the exhaust pipeline 17 is connected to the outlet of the filter 15. In this embodiment, the input end of the exhaust pipeline 17 is connected to the outlet of the circulating fan 16, for example. In the coal pulverizer 13, the inert gas dries the coal, and the moisture in the coal is converted into water vapor, which is filtered out by the filter 15 together with the inert gas, so the gas at the outlet of the filter 15 contains water vapor. By setting the exhaust pipeline 17, part of the gas at the outlet of the filter 15 is discharged to the environment, which can reduce the moisture content of the gas in the coal pulverizing drying system, prevent moisture from entering the coal again, and ensure that the filter 15 can output dry pulverized coal.

[0038] See also Figure 1 As shown, in one embodiment of the utility model, a control valve 19 is provided on the exhaust pipeline 17. There is at least one control valve 19, for example. In this embodiment, there is one control valve 19, for example, and the control valve 19 is, for example, a ball valve, a solenoid valve, a gate valve or a butterfly valve. By providing the control valve 19, it is possible to control whether the gas at the outlet of the filter 15 can flow in the exhaust pipeline 17.

[0039] See also Figure 1 As shown, in one embodiment of the utility model, an analyzer 20 is further provided on the exhaust line 17, and the analyzer 20 is provided on one side of the control valve 19. By providing the analyzer 20, the nitrogen oxide content of the gas in the exhaust line 17 can be detected to determine whether the gas discharged from the exhaust line 17 meets the environmental emission requirements.

[0040] See also Figure 1 As shown, in one embodiment of the utility model, the return line 18 is arranged in parallel with the exhaust line 17, and the input end of the return line 18 is connected to the outlet of the filter 15. In this embodiment, the return line 18 is connected to the outlet of the circulating fan 16, for example. By setting the return line 18, part of the inert gas at the outlet of the filter 15 is circulated to the inert gas generator 12, and after being heated, it continues to be used as a heat source to dry the coal, thereby avoiding gas waste and improving utilization efficiency.

[0041] See also Figure 1As shown, in one embodiment of the utility model, the return line 18 includes, for example, a first branch line 181 and a second branch line 182, etc. The first branch line 181 and the second branch line 182 are arranged in parallel, the output end of the first branch line 181 is connected to the inert gas generator 12, and the output end of the second branch line 182 is connected to the gas input line 11. In this embodiment, the output end of the second branch line 182 is connected to the ambient air input line 112, and the gas in the second branch line 182 and the ambient air in the ambient air input line 112 enter the inert gas generator 12 together, and the fuel gas and the ambient air burn in the combustion chamber of the inert gas generator 12 to generate hot flue gas, and the hot flue gas flows out of the combustion chamber together with the gas input into the inert gas generator 12 from the second branch line 182, and is mixed and heated with the gas input into the inert gas generator 12 from the first branch line 181, and flows out of the inert gas generator 12. Since the inert gas needs to consume heat to dry the coal, the temperature of the gas at the outlet of the filter 15 is much lower than the temperature of the combustion chamber of the inert gas generator 12. By setting the second branch line 182, part of the gas at the outlet of the filter 15 is sent into the combustion chamber of the inert gas generator 12 together with the ambient air in the ambient air input pipeline 112, which can reduce the core temperature of the combustion chamber of the inert gas generator 12, thereby reducing the nitrogen oxides generated when the fuel gas is burned, reducing the nitrogen oxides in the gas at the outlet of the inert gas generator 12, and further reducing the nitrogen oxides in the gas discharged from the exhaust pipeline 17, thereby reducing the harm of the coal grinding drying system to the environment.

[0042] See also Figure 1 As shown, in one embodiment of the utility model, the second branch line 182 is provided with an inlet valve 21, a flow meter 22, a regulating valve 23, a circulating flue gas induced draft fan 24, an outlet valve 25 and a one-way valve 26, etc. Among them, the inlet valve 21 is provided on the second branch line 182, for example, and the inlet valve 21 is at least one. In this embodiment, the inlet valve 21 is one, for example, and the inlet valve 21 is a ball valve, a butterfly valve, a gate valve or a solenoid valve, etc. By providing the inlet valve 21, it is possible to control whether the gas at the outlet of the filter 15 can flow into the second branch line 182.

[0043] See also Figure 1 As shown, in one embodiment of the utility model, the flow meter 22 is, for example, disposed on the second branch line 182 on one side of the inlet valve 21. There is, for example, at least one flow meter 22. In this embodiment, there is, for example, one flow meter 22, which is used to detect the flow rate of the gas flowing in the second branch line 182.

[0044] See also Figure 1As shown, in one embodiment of the utility model, the regulating valve 23 is, for example, disposed on the second branch line 182 on the side of the flow meter 22 away from the inlet valve 21. There is, for example, at least one regulating valve 23. In this embodiment, there is, for example, one regulating valve 23, which is used to change the flow rate of the gas flowing in the second branch line 182.

[0045] See also Figure 1 As shown, in one embodiment of the present invention, the flow meter 22 controls the opening of the regulating valve 23. Specifically, a specific flow setting value is given in the flow meter 22. If the reading of the flow meter 22 is greater than the flow setting value, the opening of the regulating valve 23 is reduced. If the reading of the flow meter 22 is less than the flow setting value, the opening of the regulating valve 23 is increased. In this embodiment, when the analyzer 20 detects that the nitrogen oxide content of the gas in the exhaust pipeline 17 exceeds 30 mg / m 3 When the flow meter 22 is turned on, open the inlet valve 21, the regulating valve 23, the circulating flue gas induced draft fan 24 and the outlet valve 25, and adjust the opening of the regulating valve 23 so that the reading of the flow meter 22 is 400Nm 3 / h, part of the gas at the outlet of the filter 15 is introduced into the combustion chamber of the inert gas generator 12, and the measured value of the analyzer 20 is continuously observed. When the analyzer 20 measures that the nitrogen oxide content of the gas in the exhaust pipeline 17 is 30 mg / m 3 When the measured value fluctuates within the range of 0.1% to 0.2%, and the measured value fluctuates stably, the reading of the flow meter 22 at this time is defined as the flow setting value. When the reading of the flow meter 22 deviates from the flow setting value, the opening of the regulating valve 23 is automatically adjusted to keep the reading of the flow meter 22 consistent with the flow setting value, so as to achieve the purpose of making the nitrogen oxide content of the gas in the exhaust pipeline 17 meet the environmental emission requirements. By controlling the opening of the regulating valve 23 by the flow meter 22, the flow of the gas in the second branch line 182 can be automatically adjusted without too much human intervention, thereby improving the accuracy and convenience of operation.

[0046] See also Figure 1 As shown, in one embodiment of the utility model, the circulating flue gas induced draft fan 24 is arranged on the second branch line 182 on the side of the regulating valve 23 away from the flow meter 22. By arranging the circulating flue gas induced draft fan 24, the gas at the outlet of the filter 15 can be quickly sucked into the second branch line 182 with a preset flow rate, so as to meet the demand for the flow rate of the gas in the second branch line 182, thereby achieving the purpose of reducing nitrogen oxides in the exhaust gas.

[0047] See also Figure 1As shown, in one embodiment of the utility model, the outlet valve 25 is, for example, disposed on the second branch line 182 on the side of the circulating flue gas induced draft fan 24 away from the regulating valve 23. Among them, the outlet valve 25 is, for example, at least one. In this embodiment, the outlet valve 25 is, for example, one, and the outlet valve 25 is, for example, a ball valve, a butterfly valve, a gate valve, or a solenoid valve. By providing the outlet valve 25, it is possible to control whether the gas in the second branch line 182 can flow into the gas input pipeline 11.

[0048] See also Figure 1 As shown, in one embodiment of the utility model, the one-way valve 26 is, for example, disposed on the second branch line 182 on the side of the outlet valve 25 away from the circulating flue gas induced draft fan 24. There is, for example, at least one one-way valve 26. In this embodiment, there is, for example, one one-way valve 26, which is used to prevent the air in the ambient air input pipeline 112 from entering the second branch line 182, thereby preventing oxygen from being introduced into the coal pulverizing and drying system, and ensuring the safety of the coal pulverizing process.

[0049] In summary, the utility model proposes a coal grinding and drying system, which can output dry pulverized coal and send it to downstream devices. Moreover, the coal grinding and drying system provided by the utility model can lead the gas at the filter outlet to the combustion chamber of the inert gas generator through the second branch line, which can reduce the temperature of the combustion chamber of the inert gas generator, reduce the nitrogen oxides generated during combustion, thereby reducing the content of nitrogen oxides in the exhaust gas and reducing the harm of the system to the environment.

[0050] References throughout the specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that the specific features, structures, or characteristics described in conjunction with the embodiment are included in at least one embodiment of the utility model, and not necessarily in all embodiments. Thus, the various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics of any specific embodiment of the utility model may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the utility model embodiments described and shown herein may be based on the teachings herein and will be considered part of the spirit and scope of the utility model.

[0051] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the concept of the utility model, such as the technical solution formed by replacing the above-mentioned features with the technical features with similar functions disclosed in this application (but not limited to). In addition to the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present utility model, the remaining technical features will not be repeated here.

Claims

1. A coal grinding and drying system, characterized in that: At least: at least one gas input line; an inert gas generator connected to the gas input pipeline; a coal mill connected to an outlet of the inert gas generator; A filter connected to the outlet of the coal mill; an exhaust line, an input end of the exhaust line being connected to an outlet of the filter; as well as A reflux pipeline is arranged in parallel with the exhaust pipeline, the input end of the reflux pipeline is connected to the outlet of the filter, and the reflux pipeline includes a first branch line and a second branch line, the output end of the first branch line is connected to the inert gas generator, and the output end of the second branch line is connected to the gas input pipeline.

2. The coal grinding and drying system according to claim 1, characterized in that: When there are multiple gas input pipelines, the multiple gas input pipelines are arranged in parallel.

3. The coal grinding and drying system according to claim 2, characterized in that: The gas input pipeline includes a fuel gas input pipeline, an ambient air input pipeline and an inert gas input pipeline, and the output end of the second branch line is connected to the ambient air input pipeline.

4. The coal grinding and drying system according to claim 3, characterized in that: The coal grinding and drying system further includes an air blower, which is disposed on the ambient air input pipeline.

5. The coal grinding and drying system according to claim 1, characterized in that: The coal grinding and drying system further comprises at least one inlet valve, which is disposed on the second branch line.

6. The coal grinding and drying system according to claim 5, characterized in that: The coal grinding and drying system further comprises at least one flow meter, and the flow meter is arranged on the second branch line at one side of the inlet valve.

7. The coal grinding and drying system according to claim 6, characterized in that: The coal grinding and drying system further comprises at least one regulating valve, which is arranged on the second branch line on a side of the flow meter away from the inlet valve.

8. The coal grinding and drying system according to claim 7, characterized in that: The coal grinding and drying system further comprises a circulating flue gas induced draft fan, and the circulating flue gas induced draft fan is arranged on the second branch line on the side of the regulating valve away from the flow meter.

9. The coal grinding and drying system according to claim 8, characterized in that: The coal grinding and drying system further comprises at least one outlet valve, and the outlet valve is arranged on the second branch line on the side of the circulating flue gas induced draft fan away from the regulating valve.

10. The coal grinding and drying system according to claim 9, characterized in that: The coal grinding and drying system further comprises at least one one-way valve, which is arranged on the second branch line on the side of the outlet valve away from the circulating flue gas induced draft fan.

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