Gate valve for vertical coal mill

Abstract

The invention relates to the technical field of gate valves, in particular to a gate valve for a vertical coal mill, which comprises an outer frame serving as a valve body bearing base body, and an air inlet end and an air outlet end are symmetrically arranged on two sides of the outer frame; a blocking mechanism is arranged in the outer frame and is linearly driven by a driving piece; when the blocking mechanism is located between the air inlet end and the air outlet end, the channel communicating the air inlet end with the air outlet end is separated, and blocking is achieved. When the blocking mechanism is far away from the channel, the channel connecting the air inlet end and the air outlet end is opened, and opening is achieved; the channel is of a fracture type, and an annular air curtain mechanism is arranged in the outer frame. When the sealing plate is closed, dynamic pre-tightening sealing is achieved by means of air pressure elasticity, the service life of the sealing piece is prolonged, and the operation and maintenance cost is reduced; after opening, airflow is switched and sprayed out in the circumferential direction of the channel, an annular air curtain barrier is formed on the periphery of the channel, and it is avoided that due to dust deposition, the closing degree of the sealing plate is insufficient, and signal collection and follow-up execution actions are affected.

Description

Technical Field

[0001] This invention relates to the field of slide gate valves, and in particular to a slide gate valve for use in vertical coal mills. Background Technology

[0002] Currently, the slide gate valves used at the inlet and outlet of coal mills require the sealing plate to move vertically up and down along the valve body frame to complete the opening and closing. To achieve this movement, the existing structure leaves a break channel intersecting with the flow channel on one side of the frame. The frame is broken within the range of the sealing plate's stroke, forming an opening that directly connects with the dust-laden airflow. When the valve is open, the high-speed airflow containing coal powder enters the inner cavity of the frame through this opening. The coal powder continuously deposits and accumulates from bottom to top. When the accumulation height reaches a certain level, the sealing plate is raised by the dust as it moves downward, making it unable to reach the designed closed position. The control system relies on the sealing plate's position signal to trigger the next interlock. If the signal is missing, it is judged as "not closed," causing the coal mill to shut down urgently, interrupting the pulverizing process. Furthermore, the flow channel cannot be reliably cut off, which can easily induce safety accidents such as coal powder spillage and downstream equipment overload. On the other hand, the sealing plate side and the inner wall of the frame are fitted with a clearance sliding fit, and the two are constantly rubbing against each other when opening and closing. As the operating cycle increases, the wear accumulates and the fitting clearance gradually widens, the valve body sealing performance deteriorates, the amount of powder leakage increases, the on-site pollution intensifies, and the sealing plate or frame sleeve needs to be replaced frequently, increasing the maintenance workload and spare parts cost. Summary of the Invention

[0003] In view of the problems existing in the slide gate valves used in vertical coal mills, the present invention is proposed.

[0004] The above-mentioned technical problems are solved by the following technical solution: This invention proposes a slide gate valve for a vertical coal mill, comprising, The outer frame, which serves as the supporting base for the valve body, has air inlet and air outlet symmetrically arranged on both sides; a sealing mechanism is provided inside the outer frame, which is linearly driven by a driving component. When the blocking mechanism is located between the air inlet and the air outlet, it will block the channel connecting the air inlet and the air outlet, thus achieving blockage; when the blocking mechanism is away from the channel, the channel connecting the air inlet and the air outlet will open, thus achieving opening. The channel is a slit type, and an annular air curtain mechanism is provided inside the outer frame. When the sealing mechanism is in the open state, when the dust-laden airflow flows from the air inlet to the air outlet through the channel, the annular air curtain mechanism forms a continuous annular air curtain barrier on the outer periphery of the slit-type channel by spraying airflow along the circumference of the channel. This is used to block the dust-laden airflow from dissipating into the inner space of the outer frame and to prevent dust from accumulating inside the outer frame and affecting the closure of the sealing mechanism.

[0005] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: the thickness of the sealing mechanism is consistent with the axial dimension of the channel between the air inlet and the air outlet; when the sealing mechanism moves to the open position under the action of the driving component, it moves out of the channel area as a whole, so that the channel between the air inlet and the air outlet is completely connected to the internal cavity of the outer frame.

[0006] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: the annular air curtain mechanism consists of air collecting hoods symmetrically assembled on both sides of the outer frame and airflow holes evenly distributed circumferentially on the side walls and bottom of the outer frame. The gas collection hood provides an air source for the annular air curtain and sprays air into the channel inside the outer frame through airflow holes in an encircling manner.

[0007] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: the sealing mechanism includes a sealing plate, a circular hole is provided through the sealing plate, and a circular cavity is provided inside the sealing plate. Two sealing pieces are symmetrically arranged inside the circular cavity, respectively corresponding to and sealingly fitting the inner side of the air inlet end and the air outlet end.

[0008] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: the sealing plate adopts a split design, consisting of two rectangular plates connected by bolts, so as to facilitate the replacement of excessively worn sealing plates.

[0009] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: the relative movement of the two sealing plates is guided by a plurality of guide rods, which are fixedly installed in a circular cavity and pass through the sealing plates.

[0010] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: located in a circular cavity, the gap between the two sealing plates forms a pressure chamber; When pressurized gas is introduced into the air pressure chamber, the pressure inside the chamber will act on the opposing sides of the two sealing plates, thereby driving them to move in opposite directions along the guide rod, closely adhering to the inner sides of the air inlet and outlet, thus preventing poor sealing due to wear of the sealing plates.

[0011] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: an inlet hole is provided on both sides of the sealing plate at the position corresponding to the airflow hole, and the inlet hole connects the airflow hole with the circular cavity to form a channel for conveying gas to the circular cavity.

[0012] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: each of the guide rods located between the two sealing plates is fitted with an elastic element; The elastic element is a tension spring, which has no compression margin. In its natural state, it forces the outer surfaces of the two sealing plates to remain flush with the surface of the sealing plate, providing continuous back support force to the sealing plates and limiting their retraction space when compressed.

[0013] In a preferred embodiment of the slide gate valve for a vertical coal mill according to the present invention: a dust discharge port is provided at the bottom of the outer frame, and a cover is fitted on the dust discharge port.

[0014] The beneficial effects of this invention are as follows: When the sealing plate is closed, this invention achieves dynamic pre-tightening sealing by means of air pressure elasticity, which extends the life of the sealing plate and reduces operation and maintenance costs; Once activated, the airflow switches and sprays out along the circumference of the channel, forming a ring-shaped air curtain barrier around the channel to prevent dust accumulation from causing insufficient closure of the sealing plate, which would affect signal collection and subsequent actions. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments of the present invention will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Wherein: Figure 1 A three-dimensional structural diagram of a gate valve used in a vertical coal mill is shown. Figure 2 A structural diagram of the annular air curtain mechanism in a gate valve for a vertical coal mill is shown. Figure 3 A diagram showing the airflow direction of the annular air curtain mechanism in a gate valve for a vertical coal mill is shown. Figure 4 A structural diagram of a first embodiment of the sealing mechanism in a gate valve for a vertical coal mill is shown; Figure 5 A structural diagram of a second embodiment of the sealing mechanism in a gate valve for a vertical coal mill is shown; Figure 6 The diagram shows the airflow direction under the second implementation of the blocking mechanism. Detailed Implementation

[0016] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] The terminology used in this invention is that which is currently widely used in the art in consideration of the function of the invention; however, these terms may vary according to the intent of those skilled in the art, precedent, or new technology in the art. Furthermore, specific terms may be chosen by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the invention. Therefore, the terms used in this specification should not be construed as simple names, but rather based on their meanings and the overall description of the invention.

[0018] Reference Figure 1-3 This embodiment provides a gate valve for a vertical coal mill, comprising: The outer frame 1 serves as the supporting base for the valve body, with an air inlet 2 and an air outlet 3 symmetrically arranged on both sides; a sealing mechanism 4 is provided inside the outer frame 1, which is linearly driven by a driving component 5. When the blocking mechanism 4 is located between the air inlet 2 and the air outlet 3, it will block the channel connecting the air inlet 2 and the air outlet 3, thus achieving blocking; when the blocking mechanism 4 is away from the channel, the channel connecting the air inlet 2 and the air outlet 3 will open, thus achieving opening. It should be noted that in order to achieve the vertical displacement of the sealing mechanism 4, the channel in which it is located is designed with a break structure. This results in the flow channel being directly connected to the internal space of the outer frame 1 when it is open. When the dust-laden airflow passes through, some dust will escape here and be deposited in the internal cavity of the outer frame 1. The continuous accumulation of dust will form a stack. When the stack reaches a certain thickness, it will hinder the complete closure of the sealing mechanism 4, causing it to not act properly. Since the opening and closing of the traditional sealing mechanism 4 mostly relies on signal feedback control, the incomplete action will cause the signal value to fail to be triggered normally, which will lead to the interruption of the control logic of subsequent processes, posing a safety hazard.

[0019] Furthermore, an annular air curtain mechanism 6 is provided inside the outer frame 1. When the sealing mechanism 4 is in the open state, when the dust-laden airflow flows from the air inlet 2 to the air outlet 3 through the channel, the annular air curtain mechanism 6 forms a continuous annular air curtain barrier on the outer periphery of the discontinuous channel by spraying airflow along the circumference of the channel. This is used to block the dust-laden airflow from dispersing into the inner space of the outer frame 1 and to prevent dust from accumulating inside the outer frame 1 and affecting the closure of the sealing mechanism 4.

[0020] This design utilizes the circumferential sealing characteristics of the annular air curtain barrier to strictly confine the dust-laden airflow within the channel, blocking the path of dust diffusion into the cavity of the outer frame 1. This effectively prevents dust from escaping into the cavity of the outer frame 1, keeping the operating space of the sealing mechanism 4 clean and ensuring that complete closure can always be achieved, thereby maintaining the stability of signal feedback and the continuity of subsequent process control logic. Compared to traditional methods that rely on manual cleaning or regular maintenance, the automated operation of the annular air curtain barrier significantly reduces equipment maintenance costs and downtime frequency.

[0021] The thickness of the sealing mechanism 4 is consistent with the axial dimension of the channel between the air inlet end 2 and the air outlet end 3. When the sealing mechanism 4 moves to the open position under the action of the driving component 5, it moves out of the channel area as a whole, so that the channel between the air inlet end 2 and the air outlet end 3 is completely connected with the internal cavity of the outer frame 1. At this time, the dust-laden airflow flows from the air inlet end 2 to the air outlet end 3. During this process, there will be a problem of dust escaping into the interior of the outer frame 1.

[0022] The annular air curtain mechanism 6 consists of an air collection hood 61 symmetrically assembled on both sides of the outer frame 1 and airflow holes 62 evenly distributed around the side wall and bottom of the outer frame 1. The air collection hood 61 provides an air source for the annular air curtain and sprays it into the channel inside the outer frame 1 through the airflow holes 62. Specifically, an air pipe connector is installed on the gas collection hood 61, and an air pipe is fitted on the air pipe connector. The air pipe is supplied with air by the air supply equipment. The gas enters the gas collection hood 61 through the air pipe, and then continuously delivers airflow to the outer periphery of the channel through the airflow hole 62. The airflow velocity is greater than the flow velocity of the dust-laden airflow, ensuring circumferential constraint on the dust-laden airflow, effectively controlling the dust escape problem, keeping the operating space of the sealing mechanism 4 clean, ensuring that complete closure can always be achieved, thereby maintaining the stability of signal feedback and the continuity of subsequent process control logic.

[0023] The bottom of the outer frame 1 is provided with a dust discharge port, which is equipped with a cover to facilitate cleaning of the dust accumulated at the bottom of the outer frame 1.

[0024] As an optional embodiment: It should be noted that during the long-term reciprocating opening and closing process, there is continuous friction between the side of the sealing plate 41 and the inner wall of the outer frame 1, which will lead to gradual wear of the contact surface. As the wear accumulates, the fit gap between the sealing plate 41 and the inner wall of the outer frame 1 will continue to increase. When the gap exceeds the design threshold, the sealing pair fails, and the dust-laden airflow will no longer pass entirely through the preset channel, but will leak in large quantities from the increased gap, directly escaping to the working area outside the equipment, causing environmental pollution and process failure. Therefore, the sealing plate 41 needs to be replaced as a whole at regular intervals, which will increase cost waste.

[0025] Reference Figure 4 In one embodiment provided in this application, the sealing mechanism 4 includes a sealing plate 41, a circular hole 42 is provided through the sealing plate 41, and a circular cavity 43 is provided inside the sealing plate 41. Two sealing pieces 44 are symmetrically arranged inside the circular cavity 43, respectively corresponding to and sealingly fitting the inner side of the air inlet end 2 and the air outlet end 3.

[0026] Specifically, the sealing piece 44 is bolted into the circular cavity 43, and a sealing gasket is provided between the sealing piece 44 and the inner wall of the circular cavity 43, thereby achieving a sealing effect; The sealing plate 44 is larger than the air inlet 2 and the air outlet 3, so that it can completely seal the air inlet 2 and the air outlet 3 after being attached. The sealing plate 41 adopts a split design, which consists of two rectangular plates connected by bolts, so as to facilitate the replacement of the excessively worn sealing plate 44. This split structure design provides great convenience for subsequent maintenance and replacement work. When the sealing plate 44 needs to be replaced due to excessive wear after long-term use, the staff only needs to remove the bolts connecting the two rectangular plates and open the split structure of the sealing plate 41 to replace the worn sealing plate 44 separately, without having to disassemble and replace the entire sealing plate 41. This design sets the sealing plate 44 as a vulnerable replacement part of the equipment, which not only simplifies the replacement process and reduces the difficulty and workload of maintenance, but more importantly, it eliminates the need to replace the entire sealing plate 41. Only the worn core components are replaced, which greatly reduces the consumption of consumables and fundamentally reduces the operating and maintenance costs of the equipment.

[0027] As an optional embodiment: It should be noted that during the long-term reciprocating opening and closing process, there is continuous friction between the side of the sealing plate 41 and the inner wall of the outer frame 1, which will cause the contact surface to wear gradually. As the wear accumulates, the fit gap between the sealing plate 41 and the inner wall of the outer frame 1 will continue to increase. If a gap is generated, the sealing piece 44 will need to be replaced, which not only increases the maintenance frequency but also increases the replacement cost.

[0028] Reference Figure 5-6 In one embodiment provided in this application, the relative movement of the two sealing pieces 44 is guided by a plurality of guide rods 45, which are fixedly installed in the circular cavity 43 and pass through the sealing pieces 44.

[0029] Specifically, a U-shaped groove is provided on the edge of the sealing piece 44 at the position corresponding to the guide rod 45, which is used for the assembly of the guide rod 45 and facilitates disassembly and assembly.

[0030] Located inside the circular cavity 43, the gap between the two sealing plates 44 forms a pressure chamber. When pressurized gas is introduced into the pressure chamber, the pressure inside the chamber will act on the opposing sides of the two sealing plates 44, thereby driving them to move in opposite directions along the guide rod 45, closely adhering to the inner sides of the air inlet end 2 and the air outlet end 3, to avoid poor sealing due to wear of the sealing plates 44. The sealing plate 41 has inlet holes 46 on both sides corresponding to the positions of the airflow holes 62. The inlet holes 46 connect the airflow holes 62 and the circular cavity 43, forming a channel for supplying gas to the circular cavity 43.

[0031] When the sealing plate 41 is closed, the inlet hole 46 and the airflow hole 62 are connected, and the airflow will enter the air pressure chamber through the inlet hole 46. As the gas is continuously injected, the air pressure inside the air pressure chamber increases, which causes the two sealing plates 44 to move to both sides and form a seal by closely adhering to the inner side of the air inlet end 2 and the air outlet end 3. The pressure in the air pressure chamber is greater than the air pressure at the air inlet end 2. When the sealing plate 41 is open, the inlet hole 46 and the airflow hole 62 are not connected. Therefore, the airflow hole 62 continuously delivers airflow to the outer periphery of the channel. The airflow velocity is greater than the airflow velocity of the dust-laden airflow, ensuring circumferential constraint on the dust-laden airflow, effectively controlling the dust escape problem, keeping the action space of the sealing mechanism 4 clean, ensuring that it can always achieve complete closure, thereby maintaining the stability of signal feedback and the continuity of subsequent process control logic.

[0032] Each guide rod 45 located between the two sealing pieces 44 is fitted with an elastic element 47. The elastic element 47 is a tension spring, which has no compression margin. In its natural state, it forces the outer surfaces of the two sealing pieces 44 to remain flush with the surface of the sealing plate 41, providing continuous back support force for the sealing pieces 44 and limiting their retraction space when under pressure.

[0033] This design utilizes pneumatic elastic pre-tightening to achieve dynamic maintenance of sealing performance, extending the service life of the sealing plate 44 and reducing the replacement frequency and maintenance costs of the sealing plate 44.

[0034] Finally, it should be noted that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A slide gate valve for a vertical coal mill, characterized in that: include, The outer frame (1) serves as the base for supporting the valve body, with an air inlet (2) and an air outlet (3) symmetrically arranged on both sides; a sealing mechanism (4) is provided inside the outer frame (1), which is linearly driven by a driving component (5); When the blocking mechanism (4) is located between the air inlet (2) and the air outlet (3), it will block the channel connecting the air inlet (2) and the air outlet (3) to achieve blocking; when the blocking mechanism (4) is far away from the channel, the channel connecting the air inlet (2) and the air outlet (3) will open to achieve opening. The channel is a break type, and the inner part of the outer frame (1) is provided with an annular air curtain mechanism (6). When the sealing mechanism (4) is in the open state, when the dust-laden airflow flows from the air inlet (2) to the air outlet (3) through the channel, the annular air curtain mechanism (6) forms a continuous annular air curtain barrier on the outer periphery of the break type channel by spraying airflow along the circumference of the channel. This is used to block the dust-laden airflow from dispersing into the inner space of the outer frame (1) and to prevent dust from depositing in the outer frame (1) and affecting the closure of the sealing mechanism (4).

2. The slide gate valve for a vertical coal mill according to claim 1, characterized in that: The thickness of the sealing mechanism (4) is consistent with the axial dimension of the channel between the air inlet (2) and the air outlet (3); when the sealing mechanism (4) moves to the open position under the action of the driving member (5), it moves out of the channel area as a whole, so that the channel between the air inlet (2) and the air outlet (3) is completely connected to the internal cavity of the outer frame (1).

3. The slide gate valve for a vertical coal mill according to claim 2, characterized in that: The annular air curtain mechanism (6) consists of an air collection hood (61) symmetrically assembled on both sides of the outer frame (1) and airflow holes (62) evenly distributed around the side wall and bottom of the outer frame (1). The gas collection hood (61) provides an air source for the annular air curtain and sprays air into the channel inside the outer frame (1) through the airflow hole (62).

4. The slide gate valve for a vertical coal mill according to claim 3, characterized in that: The sealing mechanism (4) includes a sealing plate (41), a circular hole (42) is provided through the sealing plate (41), and a circular cavity (43) is provided inside the sealing plate (41). Two sealing pieces (44) are symmetrically arranged inside the circular cavity (43), respectively corresponding to and sealingly fitting the inner side of the air inlet (2) and the air outlet (3).

5. The slide gate valve for a vertical coal mill according to claim 4, characterized in that: The sealing plate (41) adopts a split design, consisting of two rectangular plates connected by bolts, so as to facilitate the replacement of the worn sealing plate (44).

6. The slide gate valve for a vertical coal mill according to claim 5, characterized in that: The relative movement of the two sealing pieces (44) is guided by a number of guide rods (45), which are fixedly installed in the circular cavity (43) and pass through the sealing pieces (44).

7. The slide gate valve for a vertical coal mill according to claim 6, characterized in that: Located within the circular cavity (43), the gap between the two sealing pieces (44) forms a pressure chamber; When pressurized gas is introduced into the air pressure chamber, the pressure inside the chamber will act on the opposing sides of the two sealing plates (44), thereby driving them to move in opposite directions along the guide rod (45) and closely adhere to the inner sides of the air inlet (2) and air outlet (3), thus avoiding poor sealing due to wear of the sealing plates (44).

8. The slide gate valve for a vertical coal mill according to claim 7, characterized in that: The sealing plate (41) has an inlet hole (46) on both sides corresponding to the position of the airflow hole (62). The inlet hole (46) connects the airflow hole (62) with the circular cavity (43) to form a channel for conveying gas to the circular cavity (43).

9. The slide gate valve for a vertical coal mill according to claim 8, characterized in that: Each guide rod (45) located between the two sealing pieces (44) is fitted with an elastic element (47). The elastic element (47) is a tension spring, which has no compression margin. In its natural state, it forces the outer surfaces of the two sealing pieces (44) to remain flush with the surface of the sealing plate (41), providing continuous back support force for the sealing pieces (44) and limiting their retraction space when under pressure.

10. The slide gate valve for a vertical coal mill according to claim 9, characterized in that: The bottom of the outer frame (1) is provided with a dust discharge port, and the dust discharge port is fitted with a cover.

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