Negative pressure control system of negative pressure equipment cabinet

Abstract

The utility model relates to a negative pressure control system of a negative pressure equipment cabinet, which comprises a cabinet body, an air valve box is arranged in the cabinet body, the air valve box is connected with an exhaust pipe, and the exhaust pipe extends to the outside of the cabinet body and forms an exhaust joint outside the cabinet body; the air exhaust connector is further connected with an electric air valve, an air exhaust pipe and air exhaust equipment. The electric air valve is connected between the exhaust connector and the exhaust pipe, and the exhaust equipment is connected with the electric air valve through the exhaust pipe; the electric air valve comprises a valve body, a PLC and an air pressure sensor, and the PLC controls the flow of the valve body according to the air pressure detected by the air pressure sensor. According to the negative pressure control system of the negative pressure equipment cabinet, the air pressure in the cabinet body is collected through the air pressure sensor, if negative pressure appears in the cabinet body or the negative pressure is increased to a certain value, the electric air valve is controlled to reduce air exhaust, and the situation that the cabinet body is deformed and the cabinet door is difficult to open due to the negative pressure in the cabinet body or too large negative pressure is avoided.

Description

Technical Field

[0001] The utility model relates to the field of exhaust in equipment cabinets, and in particular to a negative pressure control system for a negative pressure equipment cabinet. Background Art

[0002] In some equipment cabinets that use chemical products, such as the cabinet of the grinding liquid supply equipment used in the semiconductor industry, such as the grinding liquid supply equipment disclosed in the patent document with announcement number CN219925709U, in order to prevent the spread of odor generated in the equipment cabinet, an exhaust system is configured in the equipment cabinet, and the gas in the equipment cabinet is extracted through the exhaust system and sent to the air processing unit for treatment.

[0003] In order to prevent odor from spreading to the outside of the equipment cabinet, the exhaust system usually exhausts air 24 hours a day, and the air intake of the exhaust system is often opened to the maximum extent. Although the equipment cabinet is not absolutely sealed, negative pressure will often be generated in the equipment cabinet when the exhaust volume is greater than the fresh air intake. If the equipment cabinet is in a negative pressure state for a long time, it is easy to cause the equipment cabinet to become concave and deformed, and increase the difficulty of opening the cabinet door. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a negative pressure equipment cabinet negative pressure control system, which adjusts the exhaust flow rate according to the air pressure in the equipment cabinet to avoid the problem of equipment cabinet deformation due to negative pressure.

[0005] The technical purpose of this utility model is achieved through the following technical solutions:

[0006] A negative pressure control system for a negative pressure equipment cabinet comprises a cabinet body, in which a damper box is installed, the damper box is connected to an exhaust duct, the exhaust duct extends to the outside of the cabinet body and forms an exhaust joint on the outside of the cabinet body; the exhaust joint is also connected to an electric damper, an exhaust duct, and an exhaust device; the electric damper is connected between the exhaust joint and the exhaust duct, and the exhaust device is connected to the electric damper via the exhaust duct; the electric damper comprises a valve body, a PLC controller, and an air pressure sensor, and the PLC controller controls the flow rate of the valve body according to the air pressure detected by the air pressure sensor.

[0007] Furthermore, the air pressure sensor is arranged outside the air valve box.

[0008] Furthermore, the valve body includes an air inlet, an air outlet, a valve core, and a drive motor. The air inlet is connected to the exhaust joint, and the air outlet is connected to the exhaust duct; the valve core is movably arranged in the valve body, and the drive motor is transmission-connected to the valve body to drive the valve core to rotate in the valve body; the PLC controller controls the operation of the drive motor.

[0009] Furthermore, the valve core is a single-piece valve core or a shutter-type valve core.

[0010] Furthermore, the air valve box includes a box body, one end of the exhaust pipe is connected to the interior of the box body, an air suction port is arranged on the side wall of the box body, a turntable is arranged on the outside of the box body corresponding to the position of the air suction port, the turntable is provided with an opening of the same size and shape corresponding to the air suction port, and the turntable is rotatably arranged on the outside of the box body; when the turntable rotates until the opening and the air suction port overlap, the air suction port is connected to the interior of the cabinet, and when the turntable rotates until the opening and the air suction port no longer overlap, the air suction port is disconnected from the interior of the cabinet.

[0011] Furthermore, the exhaust joint is a flange joint or a threaded joint.

[0012] Furthermore, the exhaust joint is arranged at a position close to the top of the cabinet, and the air valve box is arranged in the cabinet at a position close to the top of the cabinet.

[0013] Compared with the prior art, the negative pressure control system of the negative pressure equipment cabinet of the utility model collects the air pressure in the cabinet through an air pressure sensor. If negative pressure appears in the cabinet or the negative pressure increases to a certain value, the electric air valve is controlled to reduce the exhaust to avoid negative pressure in the cabinet or excessive negative pressure causing deformation of the cabinet and difficulty in opening the cabinet door. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of a negative pressure equipment cabinet in an embodiment of the utility model.

[0015] Figure 2 It is a schematic diagram of the interior of a negative pressure equipment cabinet in an embodiment of the present utility model.

[0016] Figure 3 It is a schematic diagram of the valve body structure with a single-piece valve core in an embodiment of the utility model.

[0017] Figure 4 It is a schematic diagram of the valve body structure with a shutter-type valve core in an embodiment of the utility model.

[0018] Figure 5 It is a schematic diagram of the structure of the air valve box in the embodiment of the utility model.

[0019] In the figure: 1. cabinet; 2. air valve box; 3. exhaust joint; 4. electric air valve; 5. exhaust duct; 6. air inlet; 7. air outlet; 8. valve core; 9. drive motor; 10. central axis; 11. shutter; 12. rotating shaft; 13. synchronous wheel; 14. transmission belt; 15. air inlet; 16. turntable; 17. opening. DETAILED DESCRIPTION

[0020] The technical solution of the utility model is further described below in conjunction with specific implementation methods:

[0021] A negative pressure control system for a negative pressure equipment cabinet, taking a grinding liquid supply equipment cabinet as an example, Figure 1 and Figure 2As shown, it includes a cabinet 1, in which a damper box 2 is installed, the damper box 2 is connected to an exhaust duct, the exhaust duct extends to the outside of the cabinet 1 and forms an exhaust joint 3 on the outside of the cabinet 1, a flange joint or a threaded joint, and the form of the exhaust joint is set according to the interface form of the electric damper; the exhaust joint 3 is also connected to an electric damper 4, an exhaust duct 5, and an exhaust device; the electric damper 4 is connected between the exhaust joint 3 and the exhaust duct 5, and the exhaust device is connected to the electric damper 4 through the exhaust duct 5, and the exhaust device is such as an axial flow exhaust fan.

[0022] The electric air valve 4 includes a valve body, a PLC controller, and an air pressure sensor. The PLC controller controls the flow of the valve body according to the air pressure detected by the air pressure sensor. The air pressure sensor, such as the LEM33 micro differential pressure transmitter of the LEFOO brand, can detect positive pressure, negative pressure or pressure difference, and can optionally output analog signals. Controlling the opening and closing of the valve body by PLC belongs to the prior art, such as the PLC-controlled stepper motor air flow valve disclosed in the patent document with announcement number CN212178006U, which checks the air flow size through the pressure sensor and feeds back the air flow size signal to the PLC controller, and the PLC controller automatically controls the stepper motor according to the feedback signal to realize the automatic control of the air flow valve.

[0023] The air valve box 2 includes a box body, such as Figure 5 As shown, one end of the exhaust pipe is connected to the interior of the box, and an air inlet 15 is provided on the side wall of the box. A turntable 16 is provided at the position corresponding to the air inlet 15 on the outside of the box. An opening 17 of the same size and shape is provided on the turntable 16 corresponding to the air inlet 15. The turntable 16 is rotatably arranged on the outside of the box. The turntable 16 is a circular sheet structure, and a pin is provided at the center of the circle. The turntable is installed on the outside of the box through the pin. The air inlet 15 and the opening 17 are respectively distributed outside the center of the turntable 16. When the turntable 16 rotates until the opening 17 overlaps with the air inlet 15, the air inlet 15 is connected to the inside of the cabinet. When the turntable 16 rotates until the opening 17 does not overlap with the air inlet 15, the air inlet 15 is disconnected from the inside of the cabinet. The air pressure sensor is arranged outside the air valve box, avoiding the position of the air inlet.

[0024] The air valve box is arranged in the cabinet near the top of the cabinet. The cabinet and the air valve box are mainly made of PP board (polypropylene board) welded by a hot air gun. The turntable can also be made of PP board. The exhaust duct extends from the top of the air valve box to the outside of the cabinet and forms an exhaust structure at the top of the cabinet.

[0025] When in use, the overlapping area of ​​the air inlet 15 and the opening 17 at the air valve box is adjusted by manually rotating the turntable 16. During the operation of the exhaust fan, when the air pressure intensity in the cabinet 1 changes, the air pressure sensor generates analog voltage signals of different sizes, and the PLC controller processes the analog voltage signal to generate a pulse signal, and controls the operation of the stepper motor through the pulse signal. When negative pressure is generated in the cabinet or the negative pressure reaches a certain level, it means that the exhaust volume needs to be reduced. When the air pressure in the cabinet is positive, the exhaust volume can be increased.

[0026] In one embodiment, Figure 3 As shown, the valve body includes an air inlet 6, an air outlet 7, a valve core 8, a drive motor 9, and the PLC controller, the drive motor and the air pressure sensor are connected by wires. The drive motor is a stepper motor, and the PLC controller controls the operation of the drive motor. The air inlet 6 is connected to the exhaust joint 3, and the air outlet 7 is connected to the exhaust pipe 5; the valve core 8 is movably arranged in the valve body, the valve core 8 is a single-piece valve core, and the valve core 8 is a circular sheet structure. A central axis 10 is arranged in the middle of the valve core 8, and the drive motor 9 is connected to the central axis 10. The central axis 10 is driven by the drive motor 9 to rotate, so that the valve core 8 turns to different directions, changes the size of the valve path, and thus realizes the exhaust volume control.

[0027] In another embodiment, if Figure 4 As shown, the valve core is a shutter valve core, each shutter 11 is provided with a rotating shaft 12, a synchronous wheel 13 is provided at the upper end of the rotating shaft 12, and the synchronous wheels 13 are connected by a transmission belt 14. As a preferred transmission belt 14, a transmission belt with a rack on the inner side is used, and a rack is correspondingly provided on the outer side of the synchronous wheel 13, and the rack of the transmission belt 14 is meshed with the rack of the synchronous wheel 13; the driving motor 9 outside the valve body is directly connected to the rotating shaft 12 of one of the shutters 11, preferably connected to the rotating shaft 12 of the shutter 11 near the middle position.

[0028] This embodiment is only a further explanation of the utility model, not a limitation of the utility model. After reading this specification, those skilled in the art can make non-creative modifications to the embodiment as needed, but as long as it is within the scope of the claims of the utility model, it will be protected by the patent law.

Claims

1. A negative pressure control system for a negative pressure equipment cabinet, characterized in that: It includes a cabinet body, in which a damper box is installed, the damper box is connected to an exhaust duct, the exhaust duct extends to the outside of the cabinet body and forms an exhaust joint on the outside of the cabinet body; the exhaust joint is also connected to an electric damper, an exhaust duct, and an exhaust device; the electric damper is connected between the exhaust joint and the exhaust duct, and the exhaust device is connected to the electric damper via the exhaust duct; the electric damper includes a valve body, a PLC controller, and an air pressure sensor, and the PLC controller controls the flow rate of the valve body according to the air pressure detected by the air pressure sensor.

2. A negative pressure control system for a negative pressure equipment cabinet according to claim 1, characterized in that: The air pressure sensor is arranged outside the air valve box.

3. A negative pressure control system for a negative pressure equipment cabinet according to claim 1, characterized in that: The valve body includes an air inlet, an air outlet, a valve core, and a drive motor. The air inlet is connected to an exhaust joint, and the air outlet is connected to an exhaust duct. The valve core is movably arranged in the valve body, and the drive motor is transmission-connected to the valve body to drive the valve core to rotate in the valve body. The PLC controller controls the operation of the drive motor.

4. A negative pressure control system for a negative pressure equipment cabinet according to claim 3, characterized in that: The valve core is a single-piece valve core or a shutter valve core.

5. A negative pressure control system for a negative pressure equipment cabinet according to claim 1, characterized in that: The air valve box includes a box body, one end of the exhaust pipe is connected to the interior of the box body, the side wall of the box body is provided with an air suction port, and a turntable is provided on the outside of the box body corresponding to the position of the air suction port, the turntable is provided with an opening of the same size and shape corresponding to the air suction port, and the turntable is rotatably arranged on the outside of the box body; when the turntable rotates until the opening and the air suction port overlap, the air suction port is connected to the interior of the cabinet, and when the turntable rotates until the opening and the air suction port no longer overlap, the air suction port is disconnected from the interior of the cabinet.

6. A negative pressure control system for a negative pressure equipment cabinet according to claim 1, characterized in that: The exhaust joint is a flange joint or a threaded joint.

7. A negative pressure control system for a negative pressure equipment cabinet according to claim 1, characterized in that: The exhaust joint is arranged at a position close to the top of the cabinet, and the air valve box is arranged in the cabinet at a position close to the top of the cabinet.

Images