Ear-shaped pulverized coal distribution device for coal mill and coal mill

Abstract

The invention provides an ear-shaped pulverized coal distribution device for a coal mill and the coal mill, and relates to the technical field of pulverized coal distribution of the coal mills, the ear-shaped pulverized coal distribution device comprises a first separation part, a second separation part, a baffle and a pulverized coal return pipe, the first separation part is provided with a separation cavity and is provided with a first inlet and a first outlet which are communicated with the separation cavity; the first inlet is suitable for being communicated with a separator of the coal mill so as to enable pulverized coal airflow to enter the separation cavity, and the pulverized coal airflow can be separated into pulverized coal concentrated-phase airflow and pulverized coal dilute-phase airflow in the separation cavity; the second separation part is provided with a concentrated phase chamber and a dilute phase chamber, the baffle is movably connected with the concentrated phase chamber and divides the concentrated phase chamber into a first concentrated phase area and a second concentrated phase area, and an outlet of each of the first concentrated phase area and the dilute phase chamber is suitable for being communicated with a primary air powder pipe of the coal mill; and the powder return pipe is communicated with an outlet of the second concentrated phase region. Distribution adjustment of pulverized coal between the outlet of the coal mill and the primary air powder pipe can be achieved, so that air powder distribution uniformity is improved, and the overall structure is simple.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal pulverizer coal powder distribution, and particularly relates to an ear-shaped coal powder distribution device for a coal pulverizer and the coal pulverizer. BACKGROUND

[0002] Large power station coal-fired boilers generally adopt a medium-speed mill direct-fired pulverizing system. Compared with a warehouse-type pulverizing system, primary air powder in a coal powder pipeline at an outlet of the medium-speed mill coal pulverizer can be directly and real-timely supplied to a burner. The uniformity of distribution of the amount of coal powder and the amount of air in the coal powder pipeline at the outlet of the coal pulverizer will directly affect the combustion intensity distribution in the furnace. Under the background that coal-fired units generally participate in deep load regulation, only by improving the uniformity of distribution of the air and powder at the inlet of each burner in the furnace can the operation safety of the unit be ensured under deep load regulation, while the environmental protection, economy and flexibility are still taken into account.

[0003] Therefore, the coal powder distributor is used to solve the above technical problems in the related art. However, the coal powder distributor is often large in size and has high requirements for the space for on-site modification, thereby limiting the popularization and application of the coal powder distributor on existing units. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art to some extent.

[0005] To this end, an embodiment of one aspect of the present application provides an ear-shaped coal powder distribution device for a coal pulverizer. The ear-shaped coal powder distribution device for the coal pulverizer can realize distribution and regulation of coal powder between an outlet of the coal pulverizer and a primary air powder pipe, so as to improve the uniformity of distribution of the air and powder and have a simple overall structure.

[0006] An embodiment of another aspect of the present application provides a coal pulverizer.

[0007] According to an embodiment of the present application, an ear-shaped pulverized coal distribution device for a coal mill comprises a first separation member, a second separation member, a baffle and a return pipe, the first separation member has a separation cavity and is provided with a first inlet and a first outlet communicating with the separation cavity, the first inlet is adapted to communicate with a separator of the coal mill to pass a pulverized coal gas stream into the separation cavity, the pulverized coal gas stream can be separated into a pulverized coal dense phase gas stream and a pulverized coal dilute phase gas stream in the separation cavity; the second separation member has a dense phase chamber and a dilute phase chamber, the baffle is movably connected with the dense phase chamber and divides the dense phase chamber into a first dense phase area and a second dense phase area, the inlet of each of the first dense phase area, the second dense phase area and the dilute phase chamber communicates with the first outlet, the baffle can adjust the flow of the pulverized coal dense phase gas stream entering the first dense phase area and the second dense phase area when moving relative to the dense phase chamber, the outlet of each of the first dense phase area and the dilute phase chamber is adapted to communicate with a primary air pipe of the coal mill; the return pipe communicates with the outlet of the second dense phase area, and an end of the return pipe away from the second dense phase area is adapted to communicate with the separator of the coal mill.

[0008] According to an embodiment of the present application, the ear-shaped pulverized coal distribution device for the coal mill, after the pulverized coal gas stream flows out of the separator of the coal mill, can first enter the separation cavity of the first separation member to realize thick and thin separation, to obtain the pulverized coal dense phase gas stream and the pulverized coal dilute phase gas stream, the pulverized coal dense phase gas stream enters the dense phase chamber through the first outlet and is divided into two streams by the baffle, one of which enters the first dense phase area and then flows into the downstream primary air pipe together with the pulverized coal dilute phase gas stream entering the dilute phase chamber through the first outlet, and the other of which enters the second dense phase area and returns to the separator of the coal mill through the return pipe to participate in the redistribution of the pulverized coal, because the baffle can move relative to the dense phase chamber to adjust the flow of the pulverized coal dense phase gas stream entering the first dense phase area and the second dense phase area, that is, the baffle can change the proportion of the amount of the pulverized coal flowing into the downstream primary air pipe and returning to the separator of the coal mill, so that the amount of the pulverized coal and the amount of air (that is, the pulverized coal dilute phase gas stream) flowing into the downstream primary air pipe can be matched to ensure the uniformity of the distribution of the two, and therefore, compared with the related art, the present application can realize the distribution adjustment of the pulverized coal between the outlet of the coal mill and the primary air pipe to improve the uniformity of the air-pulverized coal distribution, and the overall structure is simple.

[0009] In some embodiments, the separation cavity is an arc-shaped cavity, and the separation cavity has the first inlet and the first outlet arranged oppositely in the extension direction thereof.

[0010] In some embodiments, the baffle is pivotally fitted in the dense phase chamber.

[0011] In some embodiments, the pulverized coal distribution device further comprises a rotating shaft and a sealing member, the rotating shaft is rotatably connected with the second separating member, at least a part of the rotating shaft is located in the dense phase chamber and connected with the baffle at an end away from the first outlet, and the sealing member is sleeved on the rotating shaft to seal the connection between the rotating shaft and the second separating member.

[0012] In some embodiments, the pulverized coal distribution device further comprises an opening indicating assembly arranged on the second separating member to indicate the position of the baffle in the dense phase chamber.

[0013] In some embodiments, the opening indicating assembly comprises a fixed frame and a handle, the fixed frame and the handle are both arranged outside the second separating member, the fixed frame is located at the outer circumferential side of the rotating shaft, the fixed frame is provided with scale lines, the handle is connected with the rotating shaft, and an end of the handle away from the rotating shaft is slidably connected with the fixed frame to indicate the position of the baffle in the dense phase chamber.

[0014] In some embodiments, the pulverized coal distribution device further comprises an air locking member arranged on the return pipe to prevent the pulverized coal gas flow in the separator of the coal mill from entering the return pipe.

[0015] In some embodiments, the pulverized coal distribution device further comprises a mixing member having a mixing cavity and provided with a second inlet and a second outlet communicating with the mixing cavity, the outlet of each of the first dense phase zone and the dilute phase chamber communicates with the second inlet to allow part of the pulverized coal dense phase gas flow and the pulverized coal dilute phase gas flow to enter the mixing cavity for mixing, and the second outlet is adapted to communicate with the primary air pipe of the coal mill.

[0016] In some embodiments, the mixing cavity is an arc-shaped cavity, and the mixing cavity has the second inlet and the second outlet oppositely arranged in the extension direction of the mixing cavity.

[0017] In some embodiments, at least one of the first separating member and the mixing member is a bent pipe.

[0018] A coal mill according to an embodiment of the present application comprises a separator, a pulverized coal distribution device and a primary air pipe, the separator is provided with a discharge port and a return port, the pulverized coal distribution device is the pulverized coal distribution device according to any one of the above embodiments, the first inlet of the pulverized coal distribution device communicates with the discharge port, and an end of the return pipe of the pulverized coal distribution device away from the second dense phase zone communicates with the return port, the primary air pipe is adapted to communicate with the outlet of each of the first dense phase zone and the dilute phase chamber of the pulverized coal distribution device, and an end of the primary air pipe away from the pulverized coal distribution device is adapted to communicate with a burner.

[0019] According to the coal mill of the embodiment of the present application, the coal powder distribution device is designed as a coal powder distribution device capable of matching the amount of coal powder entering the primary air powder pipe with the amount of air entering the primary air powder pipe (i.e. the coal powder dilute phase gas flow), which can ensure the uniformity of the distribution of the amount of coal powder and the amount of air, so that compared with the related art, the coal mill using the coal powder distribution device can realize the distribution adjustment of the amount of coal powder supplied to the burner, which is beneficial to improving the uniformity of the air-powder distribution at the inlet of the burner, and meets the requirements of ensuring the safety of the operation of the unit under deep load adjustment while still taking into account the environmental protection, economy and flexibility.

[0020] In some embodiments, the coal powder distribution device is multiple and arranged along the circumference of the separator, and the primary air powder pipe is multiple and corresponds to the coal powder distribution device one by one.

[0021] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a structural schematic view of an ear-shaped coal powder distribution device for a coal mill according to the embodiment of the present application.

[0023] Figure 2 is Figure 1 is a local enlarged structural schematic view of A in FIG.

[0024] Figure 3 is a local cutaway structural schematic view of an ear-shaped coal powder distribution device for a coal mill according to the embodiment of the present application.

[0025] Figure 4 is a structural schematic view of a coal mill according to the embodiment of the present application.

[0026] LIST OF REFERENCE NUMBERS 10, coal mill; 100, coal powder distribution device; 200, separator; 1, first separation piece; 11, separation cavity; 12, first inlet; 13, first outlet; 2, second separation piece; 21, dense phase chamber; 211, first dense phase area; 212, second dense phase area; 22, dilute phase chamber; 3, baffle; 4, return powder pipe; 41, first pipe section; 42, second pipe section; 5, rotating shaft; 6, sealing piece; 7, opening degree indicating assembly; 71, fixed frame; 711, scale line; 712, first stand; 713, arc-shaped scale disc; 714, second stand; 72, handle; 8. Mixing component; 81. Mixing chamber; 82. Second inlet; 83. Second outlet; 91. Discharge port; 92. Powder return port. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] like Figures 1 to 3 As shown, an ear-shaped pulverized coal distribution device 100 for a coal mill according to an embodiment of the present invention includes a first separator 1, a second separator 2, a baffle 3, and a return pulverized coal pipe 4. The first separator 1 has a separation chamber 11 and is provided with a first inlet 12 and a first outlet 13 communicating with the separation chamber 11. The first inlet 12 is adapted to communicate with the separator 200 of the coal mill to allow pulverized coal gas flow into the separation chamber 11, and the pulverized coal gas flow can be separated into a dense phase pulverized coal gas flow and a dilute phase pulverized coal gas flow in the separation chamber 11. The second separator 2 has a dense phase chamber 21 and a dilute phase chamber 22. The baffle 3 is movably connected to the dense phase chamber 21 and connects the dense phase chamber 21 to the dilute phase chamber 22. The system is divided into a first dense phase zone 211 and a second dense phase zone 212. The inlet of each of the first dense phase zone 211, the second dense phase zone 212, and the dilute phase chamber 22 is connected to the first outlet 13. When the baffle 3 moves relative to the dense phase chamber 21, it can adjust the flow rate of the pulverized coal dense phase airflow entering the first dense phase zone 211 and the second dense phase zone 212. The outlet of each of the first dense phase zone 211 and the dilute phase chamber 22 is suitable for connection to the primary air-pulverized coal pipe of the coal mill. The return pulverized coal pipe 4 is connected to the outlet of the second dense phase zone 212. The end of the return pulverized coal pipe 4 away from the second dense phase zone 212 is suitable for connection to the separator 200 of the coal mill.

[0029] According to the lug-shaped coal powder distribution device 100 for the coal mill, after the coal powder gas flow flows out of the separator 200 of the coal mill, the coal powder gas flow can first enter the separation cavity 11 of the first separation piece 1 to realize thick and thin separation, and obtain a coal powder thick phase gas flow and a coal powder thin phase gas flow. The coal powder thick phase gas flow enters the thick phase chamber 21 through the first outlet 13 and is divided into two streams by the baffle 3. One stream enters the first thick phase area 211 and then flows into the downstream primary air powder pipe together with the coal powder thin phase gas flow entering the thin phase chamber 22 through the first outlet 13. The other stream enters the second thick phase area 212 and returns to the separator 200 of the coal mill through the return powder pipe 4 to participate in the redistribution of the coal powder. The baffle 3 can move relative to the thick phase chamber 21 to adjust the flow of the coal powder thick phase gas flow entering the first thick phase area 211 and the second thick phase area 212, that is, the baffle 3 can change the proportion of the amount of coal powder flowing into the downstream primary air powder pipe and returning to the separator 200 of the coal mill, so that the amount of coal powder flowing into the downstream primary air powder pipe can be matched with the amount of air (that is, the coal powder thin phase gas flow), to ensure the uniformity of the distribution of the two, and thus the present application can realize the distribution adjustment of the coal powder between the outlet of the coal mill and the primary air powder pipe, improve the uniformity of the air-powder distribution, and has a simple overall structure.

[0030] Specifically, the return powder pipe 4 can include a first pipe segment 41 and a second pipe segment 42 in communication with each other. One end of the first pipe segment 41 away from the second pipe segment 42 is in communication with the outlet of the second thick phase area 212, and the other end of the second pipe segment 42 away from the first pipe segment 41 is adapted to be in communication with the separator 200 of the coal mill. For example, the first pipe segment 41 can be a 90° elbow pipe bent downward, and the second pipe segment 42 can extend along the direction towards the separator 200 of the coal mill and be arranged downwardly inclined. The second separation piece 2 can include a housing and a horizontal partition plate. The inner cavity of the housing is provided with the horizontal partition plate, and the horizontal partition plate divides the inner cavity of the housing into the thick phase chamber 21 and the thin phase chamber 22 arranged in the up-down direction. The thick phase chamber 21 can be located above the thin phase chamber 22.

[0031] It should be noted that the “coal powder thick phase gas flow” is a gas flow with a high concentration (or content) of coal powder, and the “coal powder thin phase gas flow” is a gas flow with a low concentration (or content) of coal powder, which is similar to an air (or wind) gas flow.

[0032] In addition, the “movably connected baffle 3 and thick phase chamber 21” can not be limited to the two modes of the sliding connection of the baffle 3 and the thick phase chamber 21 and the pivotable connection of the baffle 3 and the thick phase chamber 21 described below, so that the proportion of the first thick phase area 211 and the second thick phase area 212 in the thick phase chamber 21 can be changed by the baffle 3, that is, the volume of the two areas in the entire thick phase chamber 21.

[0033] It can be understood that the pulverized coal gas flow from the separator 200 of the coal mill can be first separated into a pulverized coal dense phase gas flow (or pulverized coal) and a pulverized coal dilute phase gas flow (or air) by the first separating member 1, and the first dense phase area 211 and the second dense phase area 212 of the second separating member 2 can further distribute the pulverized coal, which is beneficial to adjusting the amount of pulverized coal entering the downstream primary air pipe, so that the amount of pulverized coal can match the amount of air (i.e. the pulverized coal dilute phase gas flow) entering the downstream primary air pipe, and the uniformity of the distribution of the air-pulverized coal mixture entering the downstream primary air pipe can be maximized, which is strong in realization.

[0034] As shown in Figure 3 some embodiments, the separation cavity 11 is an arc-shaped cavity, and the separation cavity 11 has a first inlet 12 and a first outlet 13 oppositely arranged in the extension direction thereof, so as to obtain a pulverized coal dense phase gas flow and a pulverized coal dilute phase gas flow by using the principle that the flow inertia difference after the diversion of the pulverized coal gas flow can realize the separation of the dense and dilute phases, and the separation mode of the first separating member 1 on the pulverized coal gas flow is simplified.

[0035] It should be noted that the pulverized coal dense phase gas flow is usually located at the outer arc side (i.e. the side with a larger turning radius) of the arc-shaped cavity, and the pulverized coal dilute phase gas flow is usually located at the inner arc side (i.e. the side with a smaller turning radius) of the arc-shaped cavity.

[0036] Further, in the projection plane perpendicular to the extension direction of the arc-shaped cavity of the first separating member 1, the projection of the dense phase chamber 21 can be closer to the projection of the outer arc side of the arc-shaped cavity of the first separating member 1 than the projection of the dilute phase chamber 22, that is, the dense phase chamber 21 can correspond to the flow direction of the pulverized coal dense phase gas flow, and the dilute phase chamber 22 can correspond to the flow direction of the pulverized coal dilute phase gas flow, so as to facilitate the good separation of the pulverized coal gas flow and further simplify the structure of the pulverized coal distribution device 100.

[0037] As shown in Figure 3 some embodiments, the baffle 3 is pivotally fitted in the dense phase chamber 21, that is, the edge of the baffle 3 is attached to the inner wall surface of the dense phase chamber 21 without interference, so as to reduce air leakage and ensure the flow guiding separation effect. The "inner wall surface of the dense phase chamber 21" is the inner wall surface of the dense phase chamber 21 in the second separating member 2.

[0038] It can be understood that by rotating the baffle 3, the proportion of the first dense phase area 211 and the second dense phase area 212 in the dense phase chamber 21 can be changed, so as to conveniently adjust the flow of the pulverized coal dense phase gas flow entering the first dense phase area 211 and the second dense phase area 212.

[0039] As shown in Figures 1 to 3As shown, in some embodiments, the pulverized coal distribution device 100 further includes a rotating shaft 5 and a sealing element 6. The rotating shaft 5 is rotatably connected to the second separator 2. At least a portion of the rotating shaft 5 is located in the dense phase chamber 21 and connected to the end of the baffle 3 opposite to the first outlet 13. By rotating the rotating shaft 5, the baffle 3 is driven to rotate in the dense phase chamber 21, so that the cross-sectional area of ​​the inlet of the first dense phase zone 211 and the inlet of the second dense phase zone 212 is changed by the baffle 3, thereby adjusting the flow rate of the dense phase airflow of pulverized coal into the first dense phase zone 211 and the second dense phase zone 212. The sealing element 6 is sleeved on the rotating shaft 5 to seal the connection between the rotating shaft 5 and the second separator 2, so as to ensure that the positive pressure pulverized coal airflow inside the second separator 2 will not leak outward when the baffle 3 rotates flexibly.

[0040] For example, as shown in the figure, the rotating shaft 5 can be rotatably connected to the concentrated phase chamber 21. The rotating shaft 5 can extend in the vertical direction and is at least partially located outside the second separator 2. A sealing element 6 is fitted on the part of the rotating shaft 5 located outside the second separator 2. The end of the baffle 3 facing away from the first outlet 13 can be fitted on the rotating shaft 5.

[0041] like Figures 1 to 3 As shown, in some embodiments, the pulverized coal distribution device 100 further includes an opening indicator component 7, which is disposed on the second separator 2 to indicate the position of the baffle 3 in the dense phase chamber 21, so that the operator can intuitively know the opening degree of the baffle 3 in the dense phase chamber 21, and realize the pulverized coal distribution adjustment of the first dense phase zone 211 and the second dense phase zone 212.

[0042] like Figure 2 As shown, in some embodiments, the opening indicator component 7 includes a fixed frame 71 and a handle 72. Both the fixed frame 71 and the handle 72 are located outside the second separator 2. The fixed frame 71 is located on the outer periphery of the rotating shaft 5 and has a scale line 711. The handle 72 is connected to the rotating shaft 5, and one end of the handle 72 away from the rotating shaft 5 is slidably connected to the fixed frame 71 to indicate the position of the baffle 3 in the dense phase chamber 21.

[0043] It is understandable that by rotating the shaft 5 through the handle 72, the baffle 3 can be rotated in the dense phase chamber 21. This allows the position of the baffle 3 in the dense phase chamber 21 to be determined based on the scale value on the fixed frame 71 corresponding to the position of the handle 72. When the baffle 3 is biased towards the first dense phase zone 211, the amount of pulverized coal entering the first dense phase zone 211 decreases, resulting in a smaller proportion of pulverized coal entering the downstream primary air-pulverized coal pipe. Meanwhile, the amount of pulverized coal entering the second dense phase zone 212 increases, increasing the proportion of pulverized coal returning to the separator 200 of the coal mill for redistribution. The same applies to the opposite direction. At the same time, since the handle 72 is slidably connected to the fixed frame 71, the reliability of the scale value reading can be further guaranteed.

[0044] Specifically, the fixing frame 71 may include a first column 712, an arc-shaped dial 713, and a second column 714 connected in sequence. The end of each of the first column 712 and the second column 714 away from the arc-shaped dial 713 is connected to the second separating member 2. The arc-shaped dial 713 may have a groove and a scale line 711 along its extension direction. The handle 72 may have a slider that can slide with the groove. The handle 72 may be arranged correspondingly to the baffle 3 so as to directly obtain the position of the baffle 3 in the concentration chamber 21. For example, as shown in the figure, the handle 72 may be directly above the baffle 3.

[0045] In some embodiments, the pulverized coal distribution device 100 further includes an airlock (not shown in the figure), which is disposed on the return pipe 4 to prevent the pulverized coal airflow in the separator 200 of the coal mill from entering the return pipe 4, thereby further ensuring the reliability of pulverized coal distribution. The airlock may not be limited to an airlock plate, and can prevent the airflow in the coal mill from flowing back into the return pipe 4.

[0046] like Figures 1 to 3 As shown, in some embodiments, the pulverized coal distribution device 100 further includes a mixing element 8, which has a mixing chamber 81 and is provided with a second inlet 82 and a second outlet 83 communicating with the mixing chamber 81. The outlet of each of the first dense phase zone 211 and the dilute phase chamber 22 is connected to the second inlet 82 so that a portion of the pulverized coal dense phase airflow and the pulverized coal dilute phase airflow enter the mixing chamber 81 for mixing. The second outlet 83 is adapted to be connected to the primary air-pulverized coal pipe of the coal mill.

[0047] It is understandable that a mixing element 8 is installed between the second separator 2 and the downstream primary air-powder pipe (i.e., the primary air-powder pipe of the coal mill) to pre-mix the dilute phase airflow of pulverized coal and the dense phase airflow of pulverized coal flowing out through the first dense phase zone 211, which helps to ensure the uniformity of air-powder mixing in the downstream primary air-powder pipe.

[0048] like Figures 1 to 3 As shown, in some embodiments, the mixing chamber 81 is an arc-shaped chamber with a second inlet 82 and a second outlet 83 arranged opposite to each other in its extending direction, so as to utilize the flow inertia of the coal powder airflow after it turns to achieve the mixing of the coal powder dilute phase airflow and the coal powder dense phase airflow flowing out through the first dense phase region 211, thereby simplifying the mixing method of the coal powder airflow by the mixing component 8.

[0049] Furthermore, on the projection plane orthogonal to the extension direction of the arc-shaped cavity of the mixer 8, the projection of the dense phase chamber 21 is closer to the inner arc side projection of the arc-shaped cavity of the mixer 8 than the projection of the dilute phase chamber 22. This is beneficial to improving the mixing effect of the coal powder dilute phase airflow and the coal powder dense phase airflow flowing out through the first dense phase zone 211 in the mixing chamber 81, and further simplifies the structure of the coal powder distribution device 100.

[0050] like Figure 1As shown, in some embodiments, at least one of the first separating element 1 and the mixing element 8 is a bend, such as a 90° bend, to further simplify the overall structure of the pulverized coal distribution device 100.

[0051] Specifically, the first separating component 1 is a bent pipe; or, the mixing component 8 is a bent pipe; or, both the first separating component 1 and the mixing component 8 are bent pipes.

[0052] For example, as shown in the figure, the first separating member 1 can be bent upwards, so that the first inlet 12 is located below the first outlet 13 in the vertical direction. The mixing member 8 can be bent upwards, so that the second inlet 82 is located below the second outlet 83 in the vertical direction.

[0053] Therefore, compared with related technologies, the present invention has the advantages of small size, simple structure, low space requirements for modification, and easy application in existing units.

[0054] like Figure 4 As shown, a coal mill 10 according to an embodiment of the present invention includes a pulverized coal distribution device 100, a separator 200, and a primary air-coal pipe (not shown in the figure). The separator 200 is provided with a discharge port 91 and a return port 92. The pulverized coal distribution device 100 is the pulverized coal distribution device 100 of any of the above embodiments. The first inlet 12 of the pulverized coal distribution device 100 is connected to the discharge port 91. The end of the return port 4 of the pulverized coal distribution device 100 away from the second dense phase zone 212 is connected to the return port 92. The primary air-coal pipe is adapted to be connected to the outlet of each of the first dense phase zone 211 and the dilute phase chamber 22 of the pulverized coal distribution device 100. Based on the above structure, it can be seen that the primary air-coal pipe can be connected to the outlet of each of the first dense phase zone 211 and the dilute phase chamber 22 through the mixing element 8. The end of the primary air-coal pipe away from the pulverized coal distribution device 100 is adapted to be connected to the burner.

[0055] According to the coal mill 10 of the present invention, the pulverized coal distribution device 100 is designed to match the amount of pulverized coal entering the primary air-coal pipe with the air volume (i.e., pulverized coal dilute phase airflow) entering the primary air-coal pipe by adjusting the amount of pulverized coal entering the primary air-coal pipe. This ensures the uniformity of the distribution of pulverized coal and air volume. Therefore, compared with related technologies, the coal mill 10 using this pulverized coal distribution device 100 can realize the distribution and adjustment of the amount of pulverized coal supplied to the burner, which is beneficial to improving the uniformity of air-coal distribution at the burner inlet. This satisfies the requirement of ensuring the safety of unit operation under deep load while also taking into account environmental protection, economy and flexibility.

[0056] Specifically, the discharge port 91 can be located above the powder return port 92 in the vertical direction.

[0057] like Figure 4As shown, in some embodiments, the pulverized coal distribution device 100 is multiple and arranged along the circumference of the separator 200, and the primary air pulverized coal pipe is also multiple and corresponds to the pulverized coal distribution device 100 one by one.

[0058] It can be understood that each coal mill 10 usually has multiple primary air pulverized coal pipes, and each primary air pulverized coal pipe can be equipped with a pulverized coal distribution device 100, so that the pulverized coal flow can be distributed and adjusted among the primary air pulverized coal pipes through the adjustable contraction hole of the primary air pulverized coal pipe itself, and then the distribution and adjustment of the pulverized coal in each primary air pulverized coal pipe can be realized by adjusting the baffle 3 of the corresponding pulverized coal distribution device 100 on each primary air pulverized coal pipe, and finally the uniform distribution of the pulverized coal among the primary air pulverized coal pipes at the outlet of the coal mill 10 can be realized through fine adjustment.

[0059] Now, the working process of the pulverized coal distribution device will be described in combination with the specific structure thereof, and specifically: The pulverized coal flow flows out from the discharge port of the separator of the coal mill, and after turning through the first separation piece (90-degree elbow), the difference in flow inertia is used to realize the thick and thin separation, so that the pulverized coal thick phase flow and the pulverized coal thin phase flow are obtained. The pulverized coal thick phase flow is on the outer arc side of the 90-degree elbow, and then enters the thick phase chamber of the second separation piece, while the pulverized coal thin phase flow is on the inner arc side of the 90-degree elbow, and then enters the thin phase chamber of the second separation piece.

[0060] Among them, the pulverized coal thick phase flow is divided into two streams by the baffle in the thick phase chamber, one stream flows through the return pipe to return to the separator of the coal mill to participate in the redistribution of the pulverized coal, and the other stream is mixed with the pulverized coal thin phase flow and then flows into the downstream primary air pulverized coal pipe. By changing the opening degree of the baffle and relying on the flow guiding effect thereof, the distribution of the pulverized coal in the first thick phase area and the second thick phase area can be changed, for example, the baffle is biased to the second thick phase area, the pulverized coal thick phase flow at the outlet of the second thick phase area is reduced, the proportion of the pulverized coal amount returned to the separator of the coal mill for redistribution is reduced, and the proportion of the pulverized coal amount entering the downstream primary air pulverized coal pipe is increased, and vice versa.

[0061] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0062] In addition, the terms "first", "second", etc. are used only to describe different instances, and are not used to indicate or imply relative importance or a number of indications of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0063] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0064] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "on", "above" and "above" the second feature can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0065] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present description, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present description and the features of different embodiments or examples, without contradiction.

[0066] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. An ear-shaped pulverized coal distribution device for a coal mill, characterized by, The coal powder distribution device comprises: a first separation member having a separation cavity and provided with a first inlet and a first outlet communicating with the separation cavity, the first inlet being adapted to communicate with a separator of the coal mill to pass a coal powder gas stream into the separation cavity, the coal powder gas stream being capable of being separated into a coal powder dense phase gas stream and a coal powder dilute phase gas stream in the separation cavity; a second separation member having a dense phase chamber and a dilute phase chamber, and a baffle movably connected with the dense phase chamber and dividing the dense phase chamber into a first dense phase area and a second dense phase area, an inlet of each of the first dense phase area, the second dense phase area and the dilute phase chamber being in communication with the first outlet, the baffle being capable of adjusting the flow of the coal powder dense phase gas stream into the first dense phase area and the second dense phase area when the baffle moves relative to the dense phase chamber, an outlet of each of the first dense phase area and the dilute phase chamber being adapted to communicate with a primary air pipe of the coal mill; a return pipe in communication with an outlet of the second dense phase area, an end of the return pipe away from the second dense phase area being adapted to communicate with the separator of the coal mill.

2. The lug-shaped coal powder distributing device for the coal mill according to claim 1, characterized in that, The separation cavity is an arc-shaped cavity, and the separation cavity has the first inlet and the first outlet oppositely arranged in an extension direction of the separation cavity.

3. The lug-shaped coal powder distributing device for the coal mill according to claim 1, characterized in that, The baffle is pivotally fitted in the dense phase chamber.

4. The lug-shaped coal powder distributing device for the coal mill according to claim 3, characterized in that, Further comprising: a rotating shaft rotatably connected with the second separation member, at least a part of the rotating shaft being located in the dense phase chamber and connected with an end of the baffle away from the first outlet; a sealing member sleeved on the rotating shaft to seal a connection between the rotating shaft and the second separation member.

5. The lug-shaped coal powder distributing device for the coal mill according to claim 1, characterized in that, Further comprising an opening degree indicating assembly provided on the second separation member to indicate a position of the baffle in the dense phase chamber.

6. The lug-shaped coal powder distributing device for the coal mill according to claim 1, characterized in that, Further comprising an air locking member provided on the return pipe to prevent the coal powder gas stream in the separator of the coal mill from entering the return pipe.

7. The lug-shaped coal powder distributing device for a coal mill according to any one of claims 1 to 6, characterized in that, Further comprising a mixing member having a mixing cavity and provided with a second inlet and a second outlet communicating with the mixing cavity, the outlets of each of the first dense phase area and the dilute phase chamber being in communication with the second inlet to make part of the coal powder dense phase gas stream and the coal powder dilute phase gas stream enter the mixing cavity to mix, the second outlet being adapted to communicate with the primary air pipe of the coal mill.

8. The lug-shaped coal powder distributing device for the coal mill according to claim 7, characterized in that, The mixing cavity is an arc-shaped cavity, and the mixing cavity has the second inlet and the second outlet oppositely arranged in an extension direction of the mixing cavity.

9. A coal mill characterised in that, The coal mill comprises: a separator provided with a discharge port and a return port; a coal powder distribution device as claimed in any one of claims 1-8, a first inlet of the coal powder distribution device being in communication with the discharge port, and an end of a return pipe of the coal powder distribution device away from a second dense phase area being in communication with the return port; a primary air pipe adapted to communicate with outlets of each of a first dense phase area and a dilute phase chamber of the coal powder distribution device, and an end of the primary air pipe away from the coal powder distribution device being adapted to communicate with a burner.

10. The coal mill of claim 9, wherein, The coal powder distribution devices are arranged in multiple and are arranged in intervals along the circumference of the separator, and the primary air powder pipes are also arranged in multiple and correspond to the coal powder distribution devices one by one.

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