Negative pressure detection device with self-cleaning function

Abstract

The utility model discloses a negative pressure detection device with self -cleaning function, including waste gas delivery pipeline (1), waste gas delivery pipeline (1) is connected with pressure detection pipe (2), pressure detection pipe (2) is connected with switch valve (3), switch valve (3) has negative pressure detection part and compressed air connecting portion, the valve core (4) in switch valve (3) has first working position and second working position, when the valve core (4) is in first working position, pressure detection pipe (2) is communicated with negative pressure detection part through valve core (4), when the valve core (4) is in second working position, pressure detection pipe (2) is communicated with compressed air connecting portion through valve core (4). The utility model can realize automatic cleaning detection port, guarantees that negative pressure table can normally work.

Description

Technical Field

[0001] This utility model relates to a negative pressure detection device with a self-cleaning function. Background Technology

[0002] In the tobacco industry, all cylindrical equipment needs to emit exhaust gas during the production process. Whether the exhaust gas emission process is normal is crucial to product quality. Therefore, negative pressure detection sensors need to be installed on the exhaust pipe to detect negative pressure in real time.

[0003] The existing negative pressure gauges are directly connected to the waste discharge pipes via connecting pipes. Because the gas contains dust and tobacco fragments, the detection port is easily blocked. Staff need to regularly disassemble the negative pressure gauges to clean the detection port, which is not only time-consuming and labor-intensive but also wastes human resources. Utility Model Content

[0004] The purpose of this invention is to provide a negative pressure detection device with a self-cleaning function to solve the technical problems in the prior art. It can automatically clean the detection port and ensure that the negative pressure gauge can work normally.

[0005] This utility model provides a negative pressure detection device with self-cleaning function, including an exhaust gas conveying pipeline, a pressure detection tube connected to the exhaust gas conveying pipeline, the pressure detection tube being connected to a switching valve, the switching valve having a negative pressure detection part and a compressed air connection part, the valve core inside the switching valve having a first working position and a second working position, when the valve core is in the first working position, the pressure detection tube is connected to the negative pressure detection part through the valve core, and when the valve core is in the second working position, the pressure detection tube is connected to the compressed air connection part through the valve core.

[0006] In the aforementioned negative pressure detection device with self-cleaning function, preferably, one end of the end housing on the switching valve is connected to the pressure detection tube, and the other end of the end housing has a first connecting flange.

[0007] In the aforementioned negative pressure detection device with self-cleaning function, preferably, the negative pressure detection unit includes a negative pressure detection housing and a negative pressure sensor. The negative pressure detection housing has a connecting pipe on its wall. The negative pressure sensor is threadedly connected to the connecting pipe. One end of the negative pressure detection housing has a second connecting flange, and the other end of the negative pressure detection housing has a third connecting flange. The second connecting flange is connected to the first connecting flange by a bolt assembly. A first sealing ring is provided between the first connecting flange and the second connecting flange.

[0008] In the aforementioned negative pressure detection device with self-cleaning function, preferably, the compressed air connection part includes a compressed air connection housing, one end of the compressed air connection housing has an end plate, the center of the end plate has a through hole, the other end of the compressed air connection housing is an open end and has a fourth connection flange, the fourth connection flange is connected to the third connection flange by a bolt assembly, and a second sealing ring is provided between the fourth connection flange and the third connection flange.

[0009] In the aforementioned negative pressure detection device with self-cleaning function, preferably, the size of the second sealing ring is the same as that of the first sealing ring, and the inner diameter of both is smaller than the inner diameter of the compressed air connection housing and the negative pressure detection housing.

[0010] In the aforementioned negative pressure detection device with self-cleaning function, preferably, the compressed air connection housing has a compressed air connection pipe on its wall, the compressed air connection pipe is provided with a first solenoid valve, and the compressed air connection pipe is connected to an air source through an air pipe.

[0011] In the aforementioned negative pressure detection device with self-cleaning function, preferably, the switching valve further includes a cylinder. The cylinder is fixed on the waste gas conveying pipe by two first support plates. The cylinder rod extends into the compressed air connection housing through the through hole and is fixedly connected to one end of the valve core. A second solenoid valve is installed on the first gas interface of the cylinder, and a third solenoid valve is installed on the second gas interface of the cylinder. A controller is fixed on the outer wall of the compressed air connection housing. The negative pressure sensor, the first solenoid valve, the second solenoid valve, and the third solenoid valve are all electrically connected to the controller.

[0012] In the aforementioned negative pressure detection device with self-cleaning function, preferably, the valve core is a cylindrical structure, the length of the valve core is greater than the distance between the first sealing ring and the second sealing ring, an air passage is provided axially inside the valve core, the outlet of the air passage is located on the end face of the valve core near the pressure detection tube, an annular groove is formed on the side wall of the valve core, and the annular groove communicates with the air passage through a number of air holes.

[0013] Compared with the prior art, this utility model achieves automatic cleaning function by controlling the position of the valve core. When the valve core is in the first working position, the negative pressure sensor can detect the negative pressure in the exhaust gas conveying pipeline normally. When the valve core is in the second working position, compressed air is connected to the pressure detection tube through the valve core to blow away impurities at the end of the pressure detection tube and solve the blockage problem. This utility model realizes automatic cleaning, enables the negative pressure sensor to work normally, and saves labor costs. Attached Figure Description

[0014] Figure 1 This is an isometric drawing of this utility model;

[0015] Figure 2 This is an exploded view of the switching valve of this utility model.

[0016] Explanation of reference numerals in the attached drawings: 1. Exhaust gas conveying pipe; 2. Pressure detection pipe; 3. Switching valve; 4. Valve core; 5. End housing; 6. First connecting flange; 7. Negative pressure detection housing; 8. Negative pressure sensor; 9. Connecting pipe; 10. Second connecting flange; 11. Third connecting flange; 12. First sealing ring; 13. Compressed air connecting housing; 14. End plate; 15. Through hole; 16. Fourth connecting flange; 17. Second sealing ring; 18. Compressed air connecting pipe; 19. First solenoid valve; 20. Cylinder; 21. First support plate; 22. Second solenoid valve; 23. Third solenoid valve; 24. Controller; 25. Air passage; 26. Ring groove; 27. Air hole. Detailed Implementation

[0017] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0018] Embodiments of this utility model: such as Figure 1 and Figure 2 As shown, a negative pressure detection device with self-cleaning function includes an exhaust gas conveying pipe 1, a pressure detection pipe 2 connected to the exhaust gas conveying pipe 1, and a switching valve 3 connected to the switching valve 3. The switching valve 3 has a negative pressure detection part and a compressed air connection part. The valve core 4 inside the switching valve 3 has a first working position and a second working position. When the valve core 4 is in the first working position, the pressure detection pipe 2 is connected to the negative pressure detection part through the valve core 4. When the valve core 4 is in the second working position, the pressure detection pipe 2 is connected to the compressed air connection part through the valve core 4.

[0019] During normal operation, valve core 4 is in the first working position. Pressure detection tube 2 is connected to negative pressure detection unit through valve core 4. Negative pressure sensor 8 on negative pressure detection unit detects negative pressure in waste gas conveying pipeline 1. When the pressure value exceeds the normal range, an alarm signal is issued.

[0020] To ensure that the negative pressure sensor 8 can always work normally, the valve core 4 is periodically switched to the second working position. At this time, the pressure detection tube 2 is connected to the compressed air connection through the valve core 4. The compressed gas blows through the pressure detection tube 2 to the connection position between the pressure detection tube 2 and the exhaust gas delivery pipe 1, blowing away the impurities accumulated on the filter screen (the filter screen is existing technology and is not shown in the figure) at the connection position, ensuring smooth gas flow. After the blowing is completed, the valve core 4 is switched back to the first working position.

[0021] Specifically, one end of the end housing 5 on the switching valve 3 is connected to the pressure detection pipe 2, and the other end of the end housing 5 has a first connecting flange 6.

[0022] In this embodiment, the pressure detection pipe 2 consists of a straight pipe section and an inclined pipe section. The angle between the axis of the inclined pipe section and the axis of the exhaust gas conveying pipe 1 is preferably 45°. The axis of the straight pipe section is parallel to the axis of the exhaust gas conveying pipe 1. By setting the inclined pipe section, the gas can be blown out obliquely during purging, thereby improving the purging effect.

[0023] Furthermore, the negative pressure detection unit includes a negative pressure detection housing 7 and a negative pressure sensor 8. The negative pressure detection housing 7 has a connecting pipe 9 on its wall. The negative pressure sensor 8 is threadedly connected to the connecting pipe 9. One end of the negative pressure detection housing 7 has a second connecting flange 10, and the other end of the negative pressure detection housing 7 has a third connecting flange 11. The second connecting flange 10 is connected to the first connecting flange 6 by a bolt assembly. A first sealing ring 12 is provided between the first connecting flange 6 and the second connecting flange 10.

[0024] The compressed air connection includes a compressed air connection housing 13. One end of the compressed air connection housing 13 has an end plate 14 with a through hole 15 in the center. The other end of the compressed air connection housing 13 is an open end with a fourth connection flange 16. The fourth connection flange 16 is connected to a third connection flange 11 by a bolt assembly. A second sealing ring 17 is provided between the fourth connection flange 16 and the third connection flange 11.

[0025] The negative pressure detection housing 7, the end housing 5, and the compressed air connection housing 13 all have the same inner and outer diameters, and are arranged coaxially.

[0026] The second sealing ring 17 has the same dimensions as the first sealing ring 12, and the inner diameters of both are smaller than the inner diameters of the compressed air connection housing 13 and the negative pressure detection housing 7.

[0027] The outer diameter of the valve core 4 is slightly larger than the inner diameter of the first sealing ring 12 and the second sealing ring 17, so as to prevent air leakage at the contact points between the first sealing ring 12 and the second sealing ring 17 and the valve core 4.

[0028] The compressed air connection housing 13 has a compressed air connection pipe 18 on its wall, and a first solenoid valve 19 is provided on the compressed air connection pipe 18. The compressed air connection pipe 18 is connected to an air source through an air pipe. The air source is existing technology and can be a gas station, air compressor, or gas cylinder, etc.

[0029] Furthermore, the switching valve 3 also includes a cylinder 20. The cylinder 20 is fixed to the exhaust gas conveying pipe 1 by two first support plates 21. The cylinder rod of the cylinder 20 extends into the compressed air connection housing 13 through the through hole 15 and is fixedly connected to one end of the valve core 4. A second solenoid valve 22 is installed on the first gas interface of the cylinder 20, and a third solenoid valve 23 is installed on the second gas interface of the cylinder 20. A controller 24 is fixed on the outer wall of the compressed air connection housing 13. The negative pressure sensor 8, the first solenoid valve 19, the second solenoid valve 22 and the third solenoid valve 23 are all electrically connected to the controller 24.

[0030] A second support plate is provided on both the compressed air connection housing 13 and the end housing 5, with the lower end of the second support plate abutting against the top of the exhaust gas conveying pipe 1. The second support plate serves to support the compressed air connection housing 13 and the end housing 5.

[0031] The cylinder 20, the first solenoid valve 19, the second solenoid valve 22, the third solenoid valve 23, and the controller 24 are existing products and can be purchased directly. This embodiment will not elaborate on their specific structures and principles. The cylinder 20 is used to move the valve core 4 between a first working position and a second working position. The controller 24 is preferably a PLC programmable controller, used to control the working states of the first solenoid valve 19, the second solenoid valve 22, and the third solenoid valve 23. The controller 24 is also used to receive negative pressure data detected by the negative pressure sensor 8 and transmit it to a smart terminal via a wireless signal. The smart terminal can be a PC, iPad, laptop, or smartphone.

[0032] Furthermore, the valve core 4 has a cylindrical structure, and the length of the valve core 4 is greater than the distance between the first sealing ring 12 and the second sealing ring 17. An air passage 25 is provided in the valve core 4 along the axial direction. The outlet of the air passage 25 is located on the end face of the valve core 4 near the pressure detection tube 2. An annular groove 26 is formed on the side wall of the valve core 4, and the annular groove 26 is connected to the air passage 25 through several air holes 27.

[0033] It should be noted that the valve core 4 will not separate from the first sealing ring 12 and the second sealing ring 17, regardless of whether it is in the first working position or the second working position.

[0034] The working principle of this utility model is as follows: During operation, the annular groove 26 on the valve core 4 is located between the first sealing ring 12 and the second sealing ring 17, that is, the annular groove 26 is located inside the negative pressure detection housing 7. The end of the valve core 4 with the air passage outlet is located inside the end housing 5. At this time, the valve core 4 is in the first working position, and the connecting pipe 9, the negative pressure detection housing 7, the air passage 25, the end housing 5, the pressure detection pipe 2, and the waste gas conveying pipeline 1 are in a connected state. At this time, the negative pressure sensor 8 can detect the negative pressure value in the waste gas conveying pipeline 1 in real time and send the detected data to the controller 24. The controller 24 sends the data to the smart terminal, and the staff can use the smart terminal to know whether the negative pressure value of the waste gas conveying pipeline 1 is normal.

[0035] At preset intervals, the controller 24 controls the exhaust port of the second solenoid valve 22 to connect with the cylinder 20, and controls the air inlet of the third solenoid valve 23 to connect with the cylinder 20. Compressed air enters the cylinder 20 through the third solenoid valve 23, pushing the cylinder rod of the cylinder 20 to move. The cylinder rod moves the valve core 4 to the left. When it moves to the limit position, the annular groove 26 on the valve core 4 is located to the left of the second sealing ring 17, that is, the annular groove 26 is located in the compressed air connection housing 13. The end of the valve core 4 with the air passage outlet is still located in the end housing 5. At this time, the valve core 4 is in the second working position. At this time, the compressed air connection pipe 18, the compressed air connection housing 13, the air passage 25, the end housing 5, the pressure detection pipe 2, and the exhaust gas delivery pipe 1 are connected. The controller 24 controls the first solenoid valve 19 to open, and the compressed air blows the filter screen at the connection position of the pressure detection pipe 2 and the exhaust gas delivery pipe 1, blowing away the debris on the filter screen, realizing automatic cleaning of the filter screen, and ensuring the accuracy of the detection data of the negative pressure sensor 8. During this process, under the action of the first sealing ring 12 and the second sealing ring 17, the gas in the compressed air connection housing 13 will not enter the negative pressure detection housing 7, thereby preventing damage to the negative pressure sensor 8.

[0036] After the preset purging time, the controller 24 controls the exhaust port of the third solenoid valve 23 to connect with the cylinder 20, controls the air inlet of the second solenoid valve 22 to connect with the cylinder 20, and simultaneously controls the first solenoid valve 19 to close. At this time, the cylinder rod of the cylinder 20 extends, pushing the valve core 4 to the first working position, so that the negative pressure sensor 8 continues to work.

[0037] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this utility model. The above description is only a preferred embodiment of this utility model, but the scope of implementation of this utility model is not limited to what is shown in the drawings. Any changes made in accordance with the concept of this utility model, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, shall be within the protection scope of this utility model.

Claims

1. A negative pressure detection device with self-cleaning function, comprising an exhaust gas conveying pipe (1), characterized in that: The exhaust gas conveying pipeline (1) is connected to a pressure detection pipe (2), which is connected to a switching valve (3). The switching valve (3) has a negative pressure detection part and a compressed air connection part. The valve core (4) inside the switching valve (3) has a first working position and a second working position. When the valve core (4) is in the first working position, the pressure detection pipe (2) is connected to the negative pressure detection part through the valve core (4). When the valve core (4) is in the second working position, the pressure detection pipe (2) is connected to the compressed air connection part through the valve core (4).

2. The negative pressure detection device with self-cleaning function according to claim 1, characterized in that: One end of the end housing (5) on the switching valve (3) is connected to the pressure detection tube (2), and the other end of the end housing (5) has a first connecting flange (6).

3. The negative pressure detection device with self-cleaning function according to claim 2, characterized in that: The negative pressure detection unit includes a negative pressure detection housing (7) and a negative pressure sensor (8). The negative pressure detection housing (7) has a connecting pipe (9) on its wall. The negative pressure sensor (8) is threadedly connected to the connecting pipe (9). One end of the negative pressure detection housing (7) has a second connecting flange (10), and the other end of the negative pressure detection housing (7) has a third connecting flange (11). The second connecting flange (10) is connected to the first connecting flange (6) by a bolt assembly. A first sealing ring (12) is provided between the first connecting flange (6) and the second connecting flange (10).

4. The negative pressure detection device with self-cleaning function according to claim 3, characterized in that: The compressed air connection includes a compressed air connection housing (13), one end of which has an end plate (14), and the end plate (14) has a through hole (15) in the center. The other end of the compressed air connection housing (13) is an open end and has a fourth connection flange (16). The fourth connection flange (16) is connected to the third connection flange (11) by a bolt assembly. A second sealing ring (17) is provided between the fourth connection flange (16) and the third connection flange (11).

5. The negative pressure detection device with self-cleaning function according to claim 4, characterized in that: The second sealing ring (17) has the same size as the first sealing ring (12), and the inner diameter of both is smaller than the inner diameter of the compressed air connection housing (13) and the negative pressure detection housing (7).

6. The negative pressure detection device with self-cleaning function according to claim 4, characterized in that: The compressed air connection housing (13) has a compressed air connection pipe (18) on its pipe wall. The compressed air connection pipe (18) is provided with a first solenoid valve (19). The compressed air connection pipe (18) is connected to the air source through an air pipe.

7. The negative pressure detection device with self-cleaning function according to claim 6, characterized in that: The switching valve (3) also includes a cylinder (20). The cylinder (20) is fixed on the exhaust gas conveying pipe (1) by two first support plates (21). The cylinder rod of the cylinder (20) extends into the compressed air connection housing (13) through the through hole (15) and is fixedly connected to one end of the valve core (4). A second solenoid valve (22) is installed on the first gas interface of the cylinder (20). A third solenoid valve (23) is installed on the second gas interface of the cylinder (20). A controller (24) is fixed on the outer wall of the compressed air connection housing (13). The negative pressure sensor (8), the first solenoid valve (19), the second solenoid valve (22) and the third solenoid valve (23) are all electrically connected to the controller (24).

8. The negative pressure detection device with self-cleaning function according to claim 7, characterized in that: The valve core (4) is a cylindrical structure. The length of the valve core (4) is greater than the distance between the first sealing ring (12) and the second sealing ring (17). An air passage (25) is provided in the valve core (4) along the axial direction. The outlet of the air passage (25) is located on the end face of the valve core (4) near the pressure detection tube (2). An annular groove (26) is formed on the side wall of the valve core (4). The annular groove (26) is connected to the air passage (25) through several air holes (27).

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