Coal drying system

Abstract

The application relates to the technical field of coal drying, in particular to a coal powder drying system. The coal powder drying system comprises a deslagging machine, a drying device and a conveying assembly. The deslagging machine is provided with a deslagging space, and the deslagging space is provided with an opening for receiving slag coal. The drying device comprises a drying platform and a detector. The drying platform is used for placing coal powder, and the detector is installed on the drying platform and used for detecting the temperature and moisture content of the coal powder. The conveying assembly comprises a conveying pipeline which is connected between the deslagging machine and the drying device and communicates with the deslagging space. The conveying pipeline is used for conveying airflow in the deslagging machine to the drying device, so that the coal powder on the drying platform is dried, heat recovery is realized, heat loss is reduced, additional heating by other heating equipment is not needed, and drying cost is reduced. The conveying assembly is configured to adjust the airflow conveying amount in response to a detection signal of the detector, so that the drying effect on the coal powder and the yield of the coal powder drying are ensured, and heat waste is reduced when the coal powder drying is completed.

Description

Technical Field

[0001] This application relates to the field of coal drying technology, and in particular to a coal powder drying system. Background Technology

[0002] The high moisture and alkali metal content in Zhundong coal has a certain impact on the pulverizing and combustion systems of power plants, becoming one of the main factors restricting the development of the Zhundong coal market. High moisture content affects the pulverizing output of boiler coal mills, leading to a decrease in mill outlet temperature and affecting boiler ignition performance. High alkali metal content can cause severe coking and fouling problems on boiler heating surfaces, increasing the amount of ash and slag in the boiler ash remover, which carries more heat and thus increases boiler heat loss to some extent. Furthermore, the existing coal drying technology is characterized by high cost and low output, causing Zhundong coal to lose its advantages of stable supply and economical pricing, thus hindering the development of the Zhundong coal market. Utility Model Content

[0003] Therefore, it is necessary to provide a pulverized coal drying system to achieve low-cost pulverized coal drying, ensure pulverized coal drying output, and solve the problem of reducing system heat loss.

[0004] The pulverized coal drying system includes a slag discharger, a drying device, and a conveying assembly. The slag discharger has a slag discharge space with an opening for receiving slag coal. The drying device includes a drying platform and a detector. The drying platform is used to hold pulverized coal, and the detector is installed on the drying platform to detect the temperature and moisture content of the pulverized coal. The conveying assembly includes a conveying pipe that connects the slag discharger and the drying device and communicates with the slag discharge space. It is used to convey the airflow from the slag discharger to the drying device. The conveying assembly is configured to adjust the airflow rate in response to the detection signal from the detector.

[0005] Understandably, by setting up a conveying pipeline between the slag discharger and the drying device, the heat emitted by the slag coal in the slag discharger is transferred to the drying device to dry the coal powder on the drying platform. This fully utilizes the waste heat of the slag coal, achieves heat recovery, and reduces heat loss. Simultaneously, the drying of the coal powder does not require additional heating equipment, reducing drying costs. During the conveying process, detectors can monitor the temperature and humidity of the coal powder in real time to adjust the airflow in the conveying pipeline, ensuring the drying effect of the coal powder, thereby guaranteeing the output of dried coal powder and reducing heat waste when the coal powder is completely dried.

[0006] In one embodiment, the conveying assembly further includes a fan disposed within the conveying duct, the fan being configured to adjust its rotational speed in response to a detection signal from the detector.

[0007] In one embodiment, the drying device has a preset temperature range for drying coal powder, the preset temperature range being [Tmin, Tmax], and the temperature detection signal of the detector for the coal powder is defined as t; When t < Tmin, the fan is configured to adjust its own speed in the first speed range in response to the temperature detection signal of the detector, where Tmin is the minimum value in the preset temperature range; When t > Tmax, the fan is configured to adjust its own speed in the second speed range in response to the temperature detection signal of the detector, where Tmax is the maximum value in the preset temperature range; The rotational speed in the first speed range is greater than the rotational speed in the second speed range.

[0008] In one embodiment, when 0.8Tmin≤t<Tmin, the fan is configured to adjust its own rotational speed to gradually decrease in response to the temperature detection signal from the detector.

[0009] In one embodiment, the drying device has a preset moisture content F for drying coal powder, and the detector detects the moisture content of the coal powder as f. When f < F, the fan is configured to adjust its own speed in the third speed range in response to the detection signal of the moisture content of the detector; When f > F, the fan is configured to adjust its own speed in the fourth speed range in response to the detection signal of the moisture content of the detector; The speed in the third speed range is lower than the speed in the fourth speed range.

[0010] In one embodiment, when F < f ≤ 1.2F, the fan is configured to adjust its rotational speed to gradually decrease in response to the detection signal of the moisture content of the detector.

[0011] In one embodiment, the drying apparatus further includes a heat exchange component disposed below the drying platform and connected to the conveying component; The heat exchange assembly includes multiple heat exchange tubes and connecting bends. Any two adjacent heat exchange tubes are connected by connecting bends to form a reciprocating heat exchange loop. One of the heat exchange tubes is connected to the delivery pipeline.

[0012] In one embodiment, the slag discharger includes a housing and a conveyor belt. The housing forms a slag discharge space and has a slag discharge port communicating with the slag discharge space. The conveyor belt is located in the slag discharge space and is used to receive slag coal and transport the slag coal to the slag discharge port.

[0013] In one embodiment, a connection hole is provided on the side wall of the outer casing. The connection hole is located above the conveyor belt and on the side near the slag discharge port. The connection hole communicates with the slag discharge space. The conveying pipe passes through the connection hole and is connected to the outer casing.

[0014] In one embodiment, the pulverized coal drying system further includes a cold ash hopper, which is located above the slag discharger and is used to crush the slag coal. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the coal powder drying system provided in this application.

[0017] Reference numerals: 100, pulverized coal drying system; 10, slag discharger; 101, opening; 102, slag discharge space; 20, drying device; 21, drying platform; 22, heat exchange component; 30, detector; 40, conveying component; 41, conveying pipeline; 42, fan; 50, cold ash hopper; 60, controller. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0019] It should be noted that when a component is referred to as being "fixed to," "set on," or "properly placed on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0021] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0023] Please see Figure 1 This application provides a pulverized coal drying system 100, which includes a drying device 20 and a drying platform 21 for holding pulverized coal. The pulverized coal drying system 100 also includes a slag discharger 10 and a conveying assembly 40. The slag discharger 10 has a slag discharge space 102 with an opening 101 for receiving slag coal, which can enter the slag discharge space 102 through the opening 101 and be discharged outwards by the slag discharger 10. The conveying assembly 40 includes a conveying pipe 41 connected between the slag discharger 10 and the drying device 20, and communicates with the slag discharge space 102, for conveying the airflow in the slag discharger 10 to the drying device 20. Thus, the heat in the slag coal exchanges heat with natural air in the slag discharger 10, and the resulting hot airflow can be conveyed to the drying device 20 through the conveying pipe 41 for heating and drying the pulverized coal, realizing the recovery of heat from the slag coal, reducing heat loss, and improving energy utilization. This also eliminates the need for additional heating elements in the entire pulverized coal drying system, which helps reduce drying costs.

[0024] like Figure 1As shown, in an optional embodiment, the pulverized coal drying system 100 further includes a detector 30, which is installed on the drying platform 21 to detect the temperature and moisture content of the pulverized coal. This allows for real-time acquisition of these information, and the moisture content can be used to determine the humidity of the pulverized coal, converting the degree of moisture into a precise and intuitive numerical value for easy assessment of the degree of drying. The conveying assembly 40 is configured to adjust the airflow in response to the detection signal from the detector 30. This promotes energy conservation and reduces heat loss when the pulverized coal is fully dried. During the drying process, maintaining a relatively high airflow rate improves drying efficiency, ensures the drying effect of the pulverized coal, and ultimately guarantees the yield of dried pulverized coal.

[0025] like Figure 1 As shown, in an optional embodiment, the conveying assembly 40 further includes a fan 42 disposed within the conveying pipe 41. The fan 42 is capable of drawing hot airflow from the slag discharge space 102 to accelerate heat transfer efficiency and thereby improve drying efficiency. The fan 42 is configured to adjust its rotational speed in response to a detection signal from the detector 30 to precisely control the flow rate of the drawn hot airflow, adjust the amount of heat transferred, and achieve precise control of coal powder drying.

[0026] like Figure 1 As shown, in a specific embodiment, the pulverized coal drying system 100 further includes a controller 60. The fan 42 and the detector 30 are electrically connected to the controller 60. The detector 30 can transmit the detected signal to the controller 60. The controller 60 converts and calculates the signal and finally outputs a speed command to the fan 42 to adjust the speed of the fan 42. Since the controller 60 is well known to those skilled in the art, it will not be described in detail here.

[0027] In a specific embodiment, the drying device 20 has a preset temperature range for drying coal powder, the preset temperature range being [Tmin, Tmax], and the temperature detection signal of the coal powder by the detector 30 is defined as t.

[0028] When t < Tmin, where Tmin is the minimum value in the preset temperature range, it indicates that the temperature of the pulverized coal is low. The fan 42 is configured to adjust its own speed in response to the temperature detection signal of the detector 30 in the first speed range. The speed in the first speed range is relatively large to improve the suction efficiency of the hot airflow, so that the conveying pipe 41 delivers more hot airflow to the drying device 20, thereby increasing the drying force on the pulverized coal and accelerating the drying rate of the pulverized coal.

[0029] When t > Tmax, where Tmax is the maximum value in the preset temperature range, it indicates that the coal powder is completely or about to be completely dried, and the coal powder requires less heat. The fan 42 is configured to adjust its own speed in response to the temperature detection signal of the detector 30 in the second speed range. The speed in the second speed range is smaller to save output energy and reduce heat waste.

[0030] The rotational speed in the first speed range is greater than the rotational speed in the second speed range. For example, the first speed range is [1500r, 3600r], and the second speed range is [800r, 1500r].

[0031] In a specific embodiment, the preset temperature range is defined as [80℃, 120℃], i.e., Tmin=80℃, Tmax=120℃. This means that when t < 80℃, the fan 42 operates within the first speed range to maintain a higher speed, generating a larger hot airflow and accelerating drying. When t > 120℃, the fan 42 operates within the second speed range to maintain a lower speed, reducing heat transfer to the drying device 20, while still maintaining a certain amount of heat on the drying platform 21. This facilitates the transfer of dried coal powder and allows for faster heating of new coal powder during drying.

[0032] In an optional embodiment, when 0.8Tmin≤t<Tmin, it indicates that the temperature of the pulverized coal is close to the preset temperature range. The fan 42 is configured to adjust its own speed to gradually decrease in response to the temperature detection signal of the detector 30, which is conducive to forming a buffer transition and facilitates the fan 42 to gradually transition from the first speed range to the second speed range.

[0033] In a specific embodiment, when the detector 30 detects that the coal powder temperature is within [64℃, 80℃), the fan 42 adjusts its own speed to gradually decrease.

[0034] In a specific embodiment, the drying device 20 has a preset moisture content F for drying coal powder, and the detector 30 detects the moisture content of the coal powder as f.

[0035] When f < F, it indicates that the moisture content of the pulverized coal is low, the humidity is low, and the required heat is low. The fan 42 is configured to adjust its own speed in the third speed range in response to the moisture content detection signal of the detector 30. The speed in the third speed range is low, which helps to reduce the transport of hot airflow, so as to save the output energy and reduce the waste of heat. When f > F, it indicates that the moisture content of the pulverized coal is relatively high. The blower 42 is configured to adjust its own speed in the fourth speed range in response to the moisture content detection signal of the detector 30. The speed in the fourth speed range is relatively high, so as to increase the delivery of hot airflow, promote the rapid drying of pulverized coal, and improve the drying efficiency.

[0036] The speeds within the third speed range are lower than those within the fourth speed range. For example, the third speed range is [800r, 2000r], and the fourth speed range is (2000r, 3600r). The third speed range can be set to the same as the second speed range, or it can only partially overlap with the second speed range. Similarly, the first and fourth speed ranges can be set to the same as the first speed range, or they can only partially overlap with the first speed range; no specific limitations are imposed here.

[0037] In specific embodiments, 12% ≤ F ≤ 17% is defined, for example, F = 12%, 15% or 17%.

[0038] In an optional embodiment, when F < f ≤ 1.2F, it indicates that the moisture content of the pulverized coal is close to the preset moisture content. The blower 42 is configured to adjust its own speed to gradually decrease in response to the moisture content detection signal from the detector 30, which facilitates a buffer transition and allows the blower 42 to gradually transition from the fourth speed range to the third speed range. Taking F = 15% as an example, when 15% < f ≤ 18%, the blower 42 adjusts its own speed component to decrease.

[0039] like Figure 1 As shown, in an optional embodiment, the drying device 20 further includes a heat exchange component 22, which is located below the drying platform 21 and connected to the conveying component 40. The conveying component 40 conveys hot air to the heat exchange component 22, and the heat is transferred to the drying platform 21 through the heat exchange component 22.

[0040] In a specific embodiment, the heat exchange assembly 22 includes multiple heat exchange tubes and connecting bends. Any two adjacent heat exchange tubes are connected by the connecting bends to form a reciprocating heat exchange loop. One of the heat exchange tubes is connected to the conveying pipe 41 to receive the hot air flow in the conveying pipe 41. The heat exchange tubes and the connecting bends cooperate to form a reciprocating heat exchange loop, which can extend the heat exchange time of the hot air flow and promote the full utilization of heat.

[0041] In a specific embodiment, the slag discharger 10 includes a shell and a conveyor belt. The shell forms a slag discharge space 102 and is provided with a slag discharge port communicating with the slag discharge space 102. The conveyor belt is located in the slag discharge space 102 and is used to receive slag coal and transport the slag coal to the slag discharge port. During the process of conveying the slag coal, it exchanges heat with natural wind and can be cooled from about 800°C to 100°C. After heat exchange with natural wind, it forms hot air at about 400°C.

[0042] In a specific embodiment, the side wall of the outer shell is provided with a connection hole, which is connected to the slag discharge space 102. The connection hole is located above the conveyor belt and on the side close to the slag discharge port to ensure that the slag coal and natural wind exchange heat fully to form hot air of sufficient temperature. The conveying pipe 41 passes through the connection hole and is connected to the outer shell. The hot air of sufficient temperature formed can enter the conveying pipe 41 through the connection hole on the side wall.

[0043] like Figure 1 As shown, in a specific embodiment, the pulverized coal drying system 100 also includes a cold ash hopper 50, which is located above the slag discharge machine 10. The cold ash hopper 50 is used to crush the slag coal so that when the slag coal falls into the slag discharge machine 10, it has a large heat exchange area and can fully exchange heat with the natural air, thereby improving the heat exchange efficiency and facilitating slag discharge.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make appropriate modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A pulverized coal drying system, characterized in that, include: The slag discharge machine (10) is provided with a slag discharge space (102), and the slag discharge space (102) is provided with an opening (101) for receiving slag coal. The drying device (20) includes a drying platform (21) for placing coal powder; A detector (30) is installed on the drying platform (21) for detecting the temperature and moisture content of the coal powder; The conveying assembly (40) includes a conveying pipe (41) connected between the slag discharger (10) and the drying device (20) and communicating with the slag discharge space (102) for conveying airflow in the slag discharger (10) to the drying device (20). The conveying assembly (40) is configured to adjust the airflow delivery rate in response to a detection signal from the detector (30).

2. The pulverized coal drying system according to claim 1, characterized in that, The conveying assembly (40) also includes a fan (42) disposed within the conveying pipe (41), the fan (42) being configured to adjust its rotational speed in response to a detection signal from the detector (30).

3. The pulverized coal drying system according to claim 2, characterized in that, The drying device (20) has a preset temperature range for drying the coal powder, the preset temperature range being [Tmin, Tmax], and the temperature detection signal of the coal powder by the detector (30) is defined as t; When t < Tmin, the fan (42) is configured to adjust its own speed in a first speed range in response to the temperature detection signal of the detector (30), where Tmin is the minimum value in the preset temperature range; When t > Tmax, the fan (42) is configured to adjust its own speed in the second speed range in response to the temperature detection signal of the detector (30), where Tmax is the maximum value in the preset temperature range; The rotational speed in the first rotational speed range is greater than the rotational speed in the second rotational speed range.

4. The pulverized coal drying system according to claim 3, characterized in that, When 0.8Tmin≤t<Tmin, the fan (42) is configured to adjust its own rotation speed to gradually decrease in response to the temperature detection signal of the detector (30).

5. The pulverized coal drying system according to claim 2, characterized in that, The drying device (20) has a preset moisture content F for drying the coal powder, and the detector (30) detects the moisture content of the coal powder as f. When f < F, the fan (42) is configured to adjust its own speed in the third speed range in response to the moisture content detection signal of the detector (30); When f > F, the fan (42) is configured to adjust its own speed in the fourth speed range in response to the moisture content detection signal of the detector (30); The rotational speed in the third rotational speed range is less than the rotational speed in the fourth rotational speed range.

6. The pulverized coal drying system according to claim 2, characterized in that, When F < f ≤ 1.2F, the fan (42) is configured to adjust its rotational speed to gradually decrease in response to the moisture content detection signal of the detector (30).

7. The pulverized coal drying system according to any one of claims 1 to 6, characterized in that, The drying device (20) further includes a heat exchange component (22), which is located below the drying platform (21) and connected to the conveying component (40); The heat exchange assembly (22) includes multiple heat exchange tubes and connecting bends. Any two adjacent heat exchange tubes are connected by the connecting bends to form a reciprocating heat exchange loop. One of the heat exchange tubes is connected to the conveying pipe (41).

8. The pulverized coal drying system according to any one of claims 1 to 6, characterized in that, The slag discharge machine (10) includes a shell and a conveyor belt. The shell forms the slag discharge space (102) and has a slag discharge port connected to the slag discharge space (102). The conveyor belt is located in the slag discharge space (102) and is used to receive the slag coal and transport the slag coal to the slag discharge port.

9. The pulverized coal drying system according to claim 8, characterized in that, The outer casing has a connection hole on its side wall. The connection hole is located above the conveyor belt and on the side near the slag discharge port. The connection hole is connected to the slag discharge space (102). The conveying pipe (41) passes through the connection hole and is connected to the outer casing.

10. The pulverized coal drying system according to any one of claims 1 to 6, characterized in that, The coal powder drying system (100) also includes a cold ash hopper (50), which is located above the slag discharge machine (10) and is used to crush the slag coal.

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