Dry screw compressor inlet valve

Abstract

The application relates to the technical field of compressors, in particular to an air inlet valve of a dry screw compressor, which can reduce the torque requirement of an actuator, improve product stability and is not prone to faults, and the air inlet valve comprises a vent butterfly valve, an air inlet butterfly valve and an actuator, characterized in that the air inlet butterfly valve is coaxially connected with the vent butterfly valve and the actuator at two ends, the air inlet butterfly valve comprises a first valve body, a circular first valve plate is arranged in the first valve body and is arranged on a first rotating shaft, a vacuum regulating valve is arranged beside the first valve plate, the distance between the central shaft of the first rotating shaft and the sealing cross section of the first valve plate is L1, the first rotating shaft is arranged eccentrically and the eccentric distance between the first rotating shaft and the center of the first valve plate is L2, the vent butterfly valve comprises a second valve body, an elliptical second valve plate is arranged in the second valve body and is arranged on a second rotating shaft, the distance between the central shaft of the second rotating shaft and the sealing cross section of the second valve plate is L3, and the second rotating shaft is arranged eccentrically and the eccentric distance between the second rotating shaft and the center of the second valve plate is L4.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, specifically to an intake valve for a dry screw compressor. Background Technology

[0002] Dry screw air compressors are a common type of positive displacement compressor. In practical use, the compressor needs to achieve unloading start-up, start-up vacuum adjustment, and unloading venting functions. A simplified flowchart of its workflow is shown below. Figure 1 As shown.

[0003] Under load conditions, air passes through a filter and enters the compressor 3 under the control of the intake valve 1. Inside the compressor 3, a pair of rotors are driven by the motor 2 to mesh and compress the air. After the air pressure increases, it passes through the check valve 4 and is supplied to the pipeline network. The intake valve 1 generally consists of three parts: a piston actuator, a main intake butterfly valve, and a piston vent valve. The actuator and the vent valve share a piston shaft. A small intake orifice of fixed diameter is opened on the intake butterfly valve plate. Its structure is as follows: Figure 2 As shown in the figure. The state shown is the loading condition, which corresponds to the intake butterfly valve being fully open and the vent piston valve being fully closed.

[0004] During unloading, the hydraulic oil electro-hydraulic control valve 5 controls the proportion of high-pressure oil entering both sides of the actuator piston, closing the intake butterfly valve of intake valve 1 while simultaneously opening the vent piston valve. At this time, a small amount of air enters the compressor through a small hole on the intake butterfly valve plate and is compressed. Because the vent piston valve is open, high pressure cannot be formed. The synchronization of the intake butterfly valve and the vent piston valve is crucial; otherwise, it will cause an overpressure fault in the compressor.

[0005] Existing conventional intake valve structures, such as Figure 2 and Figure 3 As shown, conventional intake valves, including intake butterfly valves, vent piston valves, piston actuators, and intake orifices, adopt an integrated design scheme with many specifications. Due to the characteristics of the valve mechanism, a large actuation force is required under both loading and unloading conditions, which places high demands on the actuator structure. The failure rate of the actuator is the highest in the compressor system. Summary of the Invention

[0006] To address the problem that existing intake valves place high torque requirements on actuators and are prone to failure, this invention provides an intake valve for a dry screw compressor that reduces the torque requirements of the actuator, improves product stability, and is less prone to failure.

[0007] The technical solution is as follows: A dry screw compressor intake valve includes a venting butterfly valve, an intake butterfly valve, and an actuator. The intake butterfly valve is characterized in that its two ends are coaxially connected to the venting butterfly valve and the actuator, respectively. The intake butterfly valve includes a first valve body, within which a circular first valve plate is mounted via a first rotating shaft. A vacuum regulating valve is disposed beside the first valve plate. The distance between the central axis of the first rotating shaft and the sealing cross-section of the first valve plate is L1. The first rotating shaft is eccentrically positioned, and the eccentricity between it and the center of the first valve plate is L2. The venting butterfly valve includes a second valve body, within which a second valve plate with an elliptical sealing cross-section is mounted via a second rotating shaft. The distance between the central axis of the second rotating shaft and the sealing cross-section of the second valve plate is L3. The second rotating shaft is eccentrically positioned, and the eccentricity between it and the center of the second valve plate is L4. An extended cone is formed on the outer circumferential surface of the second valve plate, and an eccentric angle A1 exists between the sealing surface axis of the cone and the axis of the second valve body.

[0008] A further feature is that two vacuum regulating valves are symmetrically arranged and are rotary vacuum regulating valves.

[0009] With this invention, the first valve plate of the intake butterfly valve has two eccentric structures and is in an unbalanced state. When there is a pressure difference on both sides of the first valve plate, it has its own opening driving torque, and the torque can be adjusted by L2 and L1, reducing the torque requirement of the actuator. The second valve plate of the vent butterfly valve is an elliptical intersection line formed by the cone and the sealing surface under the eccentric angle A1. Under the eccentric design of L4 and L3, when there is a pressure difference on both sides of the second valve plate, the second valve plate itself generates a closing driving torque, and its elliptical sealing surface can be instantly disengaged, reducing the wear of the sealing surface and ensuring the long-term sealing performance of the vent butterfly valve. The coaxial connection drive ensures the synchronization of the operation of the vent butterfly valve and the intake butterfly valve, and realizes the combined use of intake butterfly valves and vent butterfly valves of different specifications. The integrated vacuum regulating valve can realize different intake volume requirements under unloading conditions, improve product stability, and reduce the likelihood of failure. Attached Figure Description

[0010] Figure 1 A simplified flowchart of the working process of a dry screw compressor;

[0011] Figure 2 This is a front view of a conventional intake valve structure.

[0012] Figure 3 for Figure 2 Top view;

[0013] Figure 4 This is a schematic diagram of the intake valve of the present invention;

[0014] Figure 5This is a schematic diagram of the intake valve structure of the present invention;

[0015] Figure 6 for Figure 5 Assembly exploded view;

[0016] Figure 7 This is a schematic diagram of the intake butterfly valve and its corresponding sealing cross-section.

[0017] Figure 8 This is a schematic diagram of the venting butterfly valve and its corresponding sealing cross-section. Detailed Implementation

[0018] See Figures 4 to 8 As shown, a dry screw compressor intake valve includes a venting butterfly valve 1, an intake butterfly valve 2, and an actuator 3. The intake butterfly valve 2 is coaxially connected to the venting butterfly valve 1 and the actuator 3 at both ends, respectively, using an ISO5211 standard interface. The actuator 3 is a standard model, driven by high-pressure air or hydraulic oil. The intake butterfly valve 2 includes a first valve body 4, within which a circular first valve plate 6 is mounted via a first rotating shaft 5. Two symmetrical vacuum regulating valves 12 are arranged beside the first valve plate 6, allowing for different intake volume requirements under unloading conditions. The central axis of the first rotating shaft 5 is aligned with the first valve... The distance between the sealing cross sections of the plates 6 is L1. The first rotating shaft 5 is eccentrically set and the eccentricity between it and the center of the first valve plate 6 is L2. The venting butterfly valve 1 includes a second valve body 7. A second valve plate 9 with an elliptical sealing cross section is installed in the second valve body 7 through the second rotating shaft 8. The distance between the central axis of the second rotating shaft 8 and the sealing cross section of the second valve plate 9 is L3. The second rotating shaft 8 is eccentrically set and the eccentricity between it and the center of the second valve plate 9 is L4. The outer peripheral surface of the second valve plate 9 forms an extended cone. There is an eccentric angle A1 between the sealing surface axis 10 of the cone and the axis 11 of the second valve body.

[0019] The first valve plate 6 of the intake butterfly valve 2 has a double eccentric structure, and two rotating vacuum regulating valves 12 are integrated therein. The main intake channel of the intake butterfly valve 2 runs from side A to side B of the first valve plate 6, and the auxiliary intake channel runs from port E to port F of the vacuum regulating valve 12. The distance between the central axis of the first rotating shaft 5 and the sealing cross-section of the first valve plate 6 is L1. The first rotating shaft 5 is eccentrically positioned, and the eccentricity between it and the center of the first valve plate 6 is L2. The sealing surface of the valve plate is circular. The vacuum regulating valve 12 has a hollow structure, and the area of ​​the connection between ports E and F is changed by rotation.

[0020] The second valve plate 9 of the venting butterfly valve 1 has a triple eccentric structure. The air passage of the venting butterfly valve 1 is from side C to side D of the second valve plate 9. The distance between the central axis of the second rotating shaft 8 and the sealing cross section of the second valve plate 9 is L3. The second rotating shaft 8 is eccentrically set and the eccentricity between it and the center of the second valve plate 9 is L4. The outer circumferential surface of the second valve plate 9 forms an extended cone. There is an eccentric angle A1 between the sealing surface axis 10 of the cone and the axis 11 of the second valve body. The sealing surface of the valve plate is elliptical.

[0021] An eccentric design can create a pressure difference, which generates the driving torque to open or close the valve plate.

Claims

1. An intake valve for a dry screw compressor, comprising a venting butterfly valve, an intake butterfly valve, and an actuator, characterized in that, The intake butterfly valve is coaxially connected to the vent butterfly valve and the actuator at both ends. The intake butterfly valve includes a first valve body, within which a circular first valve plate is mounted via a first rotating shaft. A vacuum regulating valve is located beside the first valve plate. The distance between the central axis of the first rotating shaft and the sealing cross-section of the first valve plate is L1. The first rotating shaft is eccentrically positioned, and the eccentricity between it and the center of the first valve plate is L2. The intake butterfly valve has a main intake passage and an auxiliary intake passage. The main intake passage extends from one side of the first valve plate to the other side. The auxiliary intake passage... The air passage is a hole on one side of the first valve plate of the vacuum regulating valve leading to the other side of the first valve plate. The venting butterfly valve includes a second valve body. A second valve plate with an elliptical sealing cross-section is mounted in the second valve body through a second rotating shaft. The distance between the central axis of the second rotating shaft and the sealing cross-section of the second valve plate is L3. The second rotating shaft is eccentrically set and the eccentricity between it and the center of the second valve plate is L4. An extended cone is formed on the outer peripheral surface of the second valve plate. There is an eccentric angle A1 between the sealing surface axis of the cone and the axis of the second valve body.

2. The intake valve for a dry screw compressor according to claim 1, characterized in that, Two vacuum regulating valves are symmetrically arranged and are rotary vacuum regulating valves.

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