JP5449941B2 - Poppet valve with inclined purge hole and method for reducing pressure inside poppet valve - Google Patents

Description

  The present invention relates generally to compressors, and more particularly to an improved poppet valve having a purge hole for a hypercompressor.

  Hypercompressors that produce gas pressure levels above 3,000 bar are widely used in industrial applications including, but not limited to, the production of low density polyethylene or LDPE. In order to operate this compressor efficiently, at least a part of the compressor is controlled using a suction automatic poppet valve and a discharge automatic poppet valve. FIG. 1 shows a conventional poppet valve 10 in an open position. As shown in the figure, a conventional poppet valve 10 includes a valve body 11 having a poppet or poppet shutter 12 configured to open and close a flow path of gas flowing into and out of the hyper compressor, and a poppet 12 in a closed position. And a poppet guide 16 for receiving the poppet 12 and the spring 14. As shown, when the poppet shutter 12 is pushed open, a flow path 17 (shown by several arrows in FIG. 1) is formed in the section from the inlet 18 to the outlet 20 of the conventional poppet valve 10. The flow path is defined in a space between the poppet shutter 12 and the valve body 11 and between the poppet guide 16 and the valve body 11. The poppet guide 16 of the conventional poppet valve 10 further comprises a discharge opening 22 connected along the axis 24 of the poppet guide 16 to the region where the flow stays in the internal chamber 26 of the poppet guide 16. The back pressure in the poppet chamber 26 is determined, at least in part, by the static pressure in the region of the flow path 27 around the shaft 24 of the conventional poppet valve 10.

  Such poppet valves play an important role in the reliability of hypercompressors used in LDPE production plants. The performance of such a valve depends on the properties of the selected material, the structure suitable for withstanding high gas pressures during operation, and the operating efficiency of the poppet shutter 12. Proper opening and closing of the valve is caused by the interaction between the gas flow and the valve components, the resistance acting on the poppet shutter 12 and the poppet guide 16 to open the valve, and the flow back pressure acting on the rear surface of the poppet guide 16. The gas pressure acting on the poppet guide 16 to close the conventional valve 10, the inertia force associated with the mass of the poppet shutter 12, and the spring generated by the spring 14 to close the valve. Subject to various design constraints on several dynamic stresses acting on the valve, including forces.

  Design constraints include, for example, the need to fully and stably open the shutter during the stroke of the hyper compressor piston. In this case, the pressure loss increases due to the reduction of the flow area, and the gas temperature rises, so the efficiency of the compressor is impaired. Further, when the movement of the shutter is unstable, the movable part and the stationary part are likely to collide mainly, so that maintenance time during the failure is consumed. Another example of a design constraint relates to the need to close the shutter with a return spring before the piston motion is reversed to avoid backflow. Also, the movement of a poppet that is closed early will be further accelerated by a gas resistance force acting in the same direction as the spring force. Yet another example is moving parts to prevent or minimize the increase in valve weight and cost by unnecessarily increasing the impact strength of the impact surface wear parts and valve components. And the speed at which the stationary part collides must be within an allowable range. Finally, another example of design constraints is the increased impact speed and delayed valve closure caused, among other things, by the presence of lubricants and other contaminants in the gas that adhere to various contacting surfaces. It should be related to the fact that the influence of the adhesion phenomenon that leads to

  The decline in valve performance manifests in various factors such as high gas temperature, premature wear, polymer presence, or loud noise, which results in reduced valve life. Three-dimensional fluid dynamics (or CFD) has been widely used to accurately simulate pressure loss, resistance, pressure distribution and flow coefficient in various valve operating conditions. Based on these simulation studies and experimental results, it is possible to correlate the poppet motion with the critical performance factor and predict the life of the valve, and the conventional valve structure allows the valve to be fully It is known that it cannot be opened stably.

  Therefore, it is required to develop an improved poppet valve for hypercompressors that can be opened more efficiently and maintained open, and to reduce the time required for maintenance and shutdown by enhancing compressor performance. It has been.

  By accelerating the gas flow at the rear part of the poppet valve and lowering the static pressure inside the purged inner chamber of the valve, the gas pressure acting on the poppet shutter when closing the valve is reduced, and the poppet shutter By reducing the differential pressure required for the valve when opening the valve, the opening operation of the valve can be stabilized.

  In order to solve the problems described above and known in the art, the following poppet valve is disclosed in one embodiment of the present invention. The poppet valve includes a valve body, a poppet guide that is disposed inside the valve body and forms a flow path in the section from the inlet to the outlet of the valve, a poppet shutter that is disposed inside the poppet guide, And a biasing member for biasing the poppet shutter from the poppet guide toward the inner surface of the flow inlet for blocking the path. At this time, the poppet guide further has at least one discharge hole for fluidly communicating the inner chamber of the poppet guide and the low static pressure region of the flow path.

  A poppet valve according to another embodiment of the present invention includes a valve body, a poppet guide which is disposed inside the valve body and forms a flow path in a section from the inlet to the outlet of the valve, and is disposed inside the poppet guide. A poppet shutter, a spring disposed inside the inner chamber of the poppet guide, and a purge channel inclined so as to fluidly communicate the inner chamber of the poppet guide and the low static pressure region of the channel.

  In yet another embodiment of the present invention, a method for reducing the closing pressure acting on the poppet shutter of a poppet valve is disclosed. Accelerating the flow in the flow path of the valve so as to reduce the static pressure in the region of the flow path, of which the poppet guide and valve body form part, between the inlet and the outlet of the valve; Fluid communication between the inner chamber of the poppet guide and the static pressure drop region of the flow path, thereby reducing fluid pressure acting directly on the inner surface of the poppet and acting toward the inner surface of the valve body.

  As mentioned above, although the characteristic of various embodiment which concerns on this invention was demonstrated easily, these characteristics and the effect of this invention are shown more concretely in the following detailed description. Of course, features other than those described above are also described below, and these are also intended to be included in the appended claims.

  In illustrating some of the embodiments according to the present invention, the embodiments included in the present invention are not limited to the details of the structure and component arrangement of these embodiments described below and illustrated in the accompanying drawings. I want you to understand. There are many other forms for implementing and utilizing the present invention. The terms and expressions described in the present application are used for convenience of explanation, and do not limit the embodiments of the present invention.

  Thus, as will be apparent to those skilled in the art, embodiments of the present invention inherently include structures, methods, and / or systems other than those described herein that are capable of implementing the present invention. It is. Therefore, it is noted that the appended claims encompass such equivalent measures.

  The accompanying abstract is easy to understand for the patent examiner and the general public, especially for scientists, engineers and workers in the field who are unfamiliar with patent or legal terms and expressions. It is for concise explanation. Accordingly, the attached summary does not specify or limit the teachings of the invention or the application. The teachings of the invention or the application should be construed only on the basis of the appended claims.

  The embodiments described herein will now be described in detail and will demonstrate the advantages of the present invention by a detailed description corresponding to the accompanying drawings, the following of which is a brief description.

1 is a cross-sectional view of a conventional poppet valve in an open position. FIG. 2 is a cross-sectional view of a poppet valve in an open position, according to an illustrative embodiment of the invention. FIG.

  Embodiments in accordance with the present invention generally relate to compressors, and more particularly, to improved poppet valves with purge holes for hypercompressors. By reducing the static pressure inside the purged internal chamber of the poppet guide by accelerating the gas flow in the rear part of the valve, the gas pressure acting on the internal chamber to close the valve is reduced, and the valve By reducing the differential pressure required on the valve to open the valve, the dynamic process for opening the valve can be stabilized. Several embodiments of the poppet valve according to the present invention will now be described with reference to the drawings, in which like reference numerals are given to like components throughout the drawings.

  FIG. 2 shows a poppet valve 50 according to one embodiment of the present invention. As will be apparent to those skilled in the art, the poppet valve 50 may be a suction valve or a discharge valve. In the illustration, the poppet valve 50 is in the open position. The poppet valve 50 urges the valve body 52, the shutter 54, the shutter guide 56, and the valve body away from the shutter guide, so that the poppet shutter 54 contacts the inner surface of the valve body 52 and is seated. And a spring 58. Poppet valve 50 also has an inlet 58 and an outlet 60. Explaining the action of the spring 58, the spring 58 presses the shutter 54 such that a portion 62 of the surface of the shutter 54 abuts the inner surface 64 of the valve body 52, thereby allowing gas to flow from the inlet 58 to the outlet 60, or vice versa. Prevents flowing in the direction. When the force applied to the shutter 54 by the gas pressure at the inlet 58 exceeds the biasing force of the spring 58, the shutter 54 moves to the open position, thereby causing gas to flow from the inlet 58 to the outlet 60, between the shutter 54 and the valve body 52. At the same time, it flows through a flow path 66 defined between the shutter guide 56 and the valve body 52.

As shown in FIG. 2, the shutter guide 56, together with two rear holes 68 that form part of the flow path 66, one or more for fluid communication between the inner chamber 72 of the shutter guide 56 and the flow path 66. A discharge hole 70 is provided. As further shown in FIG. 2, the discharge hole 70 is inclined with respect to the center line 74 of the poppet valve 50, so that the region of the flow path 66 where the gas flow through the poppet valve 50 is accelerating is defined in the shutter guide 56. The internal chamber 72 is connected. As the flow accelerates through the acceleration flow region, the static pressure inside the internal chamber 72 decreases, which acts on the shutter 54 and can cause the shutter 54 to press against the inner wall 64 of the valve body 52. Is reduced. In addition, as will be apparent to those skilled in the art, the amount of flow acceleration in the flow acceleration region can be controlled by selecting the diameter of the rear hole 68. In particular, the diameter D _rr of the rear hole 68 of the poppet valve 50 is smaller than the corresponding hole of the conventional valve 10 shown in FIG. For example, but not limited to, in one embodiment, the D _{rr of the} poppet valve 50 is 66% of the diameter Ddo of the discharge opening 22 of the conventional valve 10. Thus, when the poppet valve 50 and the conventional valve 10 have a similar 25 mm inlet diameter D _i , the D _do / D _i of the conventional valve 10 is about 0.6, whereas the poppet valve In the case of 50, D _rr / D _i is between 0.36 and 0.44, preferably 0.4. In addition, the inclination angle of the inclined discharge hole 70 is determined so that the spring 58 is disposed in the internal chamber 72 so that the internal chamber 72 can be reliably connected to the rear hole 68. Thus, in the exemplary embodiment described herein, the range of values for the tilt angle is between 10 degrees and 25 degrees, preferably 19 degrees.

  Therefore, as advantageous features of the poppet valve 50 of FIG. 2, for example, (1) the flow through the flow path 66 is accelerated in the region where the discharge hole 70 connects the inner chamber 72 of the shutter guide 56 to the flow path 66. And a rear hole 68 having a small diameter so as to include (1) one or a plurality of inclined discharge holes 70 that connect the rear hole 68 of the flow path 66 to the inner chamber 72 of the shutter guide 56. Due to these advantageous features, the static pressure “moves” from a low static pressure location (ie, a flow acceleration location) in the channel 66 to the inner chamber 72 of the shutter guide 56. As a result, the back pressure is reduced, and the opening of the valve becomes more stable. As mentioned above, by accelerating the gas flow in the rear part of the valve, the static pressure inside the valve chamber is reduced, thereby reducing the gas pressure acting on the internal poppet chamber to close the valve. The differential pressure along the valve required to open the valve can be reduced, resulting in a stable dynamic process of opening the valve.

  CFD simulation results taking into account fluid motion and valve kinematics prove the operation of the poppet valve 50 as described above. The mathematical model for valve kinematics is based on two differential equations. The first is related to the gas flow rate through the open valve for a constant pressure drop, and the second is the inertial force due to the shutter mass, damping force, elastic force from the return spring, and the gas passing through the valve. This relates to the law of motion of the shutter affected by the impact force of the shutter when it comes into contact with the stationary part at the end of the resistance and the movement of the shutter. Apply the two-equation eddy-viscosity turbulence model (K-ω) with wall integral boundary processing to predict the fluid flow rate by solving the Reynolds mean and Novier Strokes equations.

  One advantageous feature of the present invention that increases gas power is the movement of the purge hole. Such a hole is a volume portion of the section from the poppet to the guide so that the gas velocity in the residence area is higher than the gas residence area with the conventional valve structure (ie, the pressure applied to the backside of the poppet is higher). As a result, as will be apparent to those skilled in the art, the gas pressure is reduced and the component of the gas force acting on the shutter is higher than the spring reaction force, as will be apparent to those skilled in the art. The effect etc. can be expected.

  In yet another embodiment of the present invention, a method for reducing the closing pressure acting on the poppet shutter of a poppet valve is disclosed. Such a poppet valve closes the poppet valve by urging a valve body having a central shaft, an inlet and an outlet, a poppet guide, and a poppet shutter disposed inside the poppet guide to press the valve body. And a configured bias member. Such a method is configured to reduce the static pressure in the region of the flow path, which is arranged in fluid communication between the inlet and outlet of the valve, a portion of which is formed by the poppet guide and the valve body. The step of accelerating the internal flow and fluid communication between the inner chamber of the poppet guide and the static pressure drop area of the flow path reduce the fluid pressure acting directly on the inner surface of the poppet shutter and acting toward the inner surface of the valve body. Including the step of.

  In the disclosed method, the flow path passes through at least one hole in the poppet guide, and the low static pressure region is located within the portion of the flow path where the at least one hole is located. In addition, an alternative method for fluid communication includes fluid communication of the interior chamber of the poppet guide with the flow passage portion via at least one outlet hole disposed in the poppet guide. As described above, the low static pressure region is the flow acceleration region, and at least one discharge hole is inclined with respect to the central axis of the valve body. The inclination angle of the at least one discharge hole may vary between 10 degrees and 25 degrees. For this reason, a certain angle range is conceivable for the inclination of the at least one discharge hole, but an inclination angle of about 19 degrees is preferred.

  The embodiments according to the present invention have been illustrated and described with reference to the accompanying drawings. It will be apparent to those skilled in the art that various modifications, alterations, and omissions can be made to such embodiments without departing from the spirit of the invention and within the scope of the appended claims. Accordingly, the contemplation of the present invention should be construed broadly only based on the attached embodiments so as to cover such modifications, alterations, and omissions. Further, various modifications and reassembly of the order or manner of the disclosed steps or methods are considered alternative embodiments of the invention. All means and functions described in the appended claims inherently embrace such equivalent measures and arrangements.

Claims (15)

A valve body having a central axis, an inlet and an outlet;
A poppet guide disposed inside the valve body that forms a first portion of a flow path in a section from an inflow port to an outflow port, wherein the flow path is formed between an inner surface of the valve body and an outer surface of the poppet guide. A poppet guide formed therebetween and passing through at least one hole of the poppet guide;
A poppet shutter disposed inside the poppet guide, wherein the poppet shutter forms a second portion of the flow path in a section from the outer surface of the poppet shutter to the inner surface of the valve body;
A bias member disposed inside an inner chamber of the poppet guide, the bias member configured to bias the poppet shutter toward the inner surface of the inflow port so that the bias member blocks the flow path; A poppet valve comprising:
The poppet guide further includes at least one discharge hole for fluidly communicating the inner chamber of the poppet guide and the low static pressure region of the flow path.   The poppet valve of claim 1, wherein the at least one discharge hole is connected to the flow path through at least one hole.   The poppet valve according to claim 1 or 2, wherein the at least one discharge hole is inclined with respect to a central axis of the valve body.   The poppet valve according to claim 3, wherein an inclination angle of the at least one discharge hole varies between 10 degrees and 25 degrees.   The poppet valve of claim 4, wherein the tilt angle is about 19 degrees.   The poppet valve of claim 1, wherein the at least one discharge hole is disposed in the poppet guide to directly act on an inner surface of the poppet shutter to reduce pressure toward the valve inlet. A poppet valve comprising a poppet shutter, a valve body having a central shaft, an inlet and an outlet, a poppet guide, and biasing the poppet shutter disposed inside the poppet guide to close the poppet valve And a biasing member configured to press against the valve body to reduce a closing pressure acting on the poppet shutter of the poppet valve,
Accelerating the flow of the flow path of the valve arranged to fluidly communicate the inlet and the outlet to reduce static pressure in the region of the flow path, the portion of the flow path An acceleration step formed in the section of the valve body from the poppet guide,
Fluidly communicating the inner chamber of the poppet guide with the static pressure drop region of the flow path so as to reduce the fluid pressure that acts directly on the inner surface of the poppet shutter and closes the poppet valve toward the inner surface of the valve body. Including methods. The step of accelerating the flow further comprises accelerating the flow through at least one hole in the poppet guide;
The method of claim 7, wherein the low static pressure region is disposed in a portion of the flow path where the at least one hole is located.   8. The step of fluidly communicating includes the step of fluidly communicating an inner chamber of the poppet guide and a static pressure drop region of the flow path through at least one discharge hole disposed in the poppet guide. Or the method according to 8.   The method according to claim 9, wherein the at least one discharge hole is inclined with respect to a central axis of the valve body.   The method of claim 10, wherein an inclination angle of the at least one exhaust hole varies between 10 degrees and 25 degrees.   The method of claim 11, wherein the tilt angle is about 19 degrees. A valve body having a central axis, an inlet and an outlet;
A poppet guide disposed inside the valve body and configured to form a first portion of a flow path in a section from the inflow port to the outflow port, wherein the flow path and an inner surface of the valve body A poppet guide formed between an outer surface of the poppet guide and passing through at least one hole of the poppet guide;
A poppet shutter disposed inside the poppet guide, the poppet shutter configured to form a second portion of the flow path in a section from the outer surface of the poppet shutter to the inner surface of the valve body;
A spring disposed in the interior chamber of the poppet guide, the spring configured to bias the poppet shutter toward the inner surface of the inflow port so as to block the flow path;
A purge channel inclined with respect to the central axis of the valve body for fluid communication between the inner chamber of the poppet guide and the low static pressure region of the first portion of the channel at the position of the at least one hole And poppet valve.   14. The poppet valve of claim 13, wherein the ratio of the inlet diameter to the at least one hole diameter is in the range of about 0.36 to about 0.44.   15. The poppet valve according to claim 13 or 14, wherein an inclination angle of the at least one discharge hole varies between about 10 degrees and about 25 degrees.

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