JPS5833435B2 - Sedation device for flow control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to flow control devices, and more particularly to a sedation device for a flow control device.

A wide variety of practical applications may require structures that vary the flow rate of fluid without creating noise or vibration.

The term "throttle" is commonly applied to the function of regulating flow within a certain flow range.

The various devices that perform this function are commonly referred to as "throttle valves" to distinguish them from structures that function to open and close fluid flow paths in stages.

To the extent that an on-off valve cannot be opened or closed instantaneously, but to the extent that throttling noise and vibrations occur when opening or closing, such valves are also included in the "throttle valve," and the present invention does not apply to such valves. can be similarly applied.

Typical control valves for handling high pressure fluid flow utilize structures that allow for variable cross-sectional area of the fluid path.

Overall, this type of structure produces considerable noise and vibration;
damaged due to cavitation.

However, this type of structure is generally inexpensive and is therefore often used.

Of particular interest here is the structure for making the spool valve quiet.

In general, the noise and vibration generated by orifice valves are often caused by the Venturi effect that involves the movement of fluid through the opening.
It is something.

When the orifice is constricted to reduce its cross-sectional area,
The flow velocity becomes slower and its pressure energy becomes smaller.

The energy difference creates turbulence that is converted into an increase in the internal temperature of the fluid and acoustic energy in the form of noise transmitted through the fluid and vibrations of the surrounding structures.

Some of these acoustic energies occur at audio frequencies.

In extreme cases, turbulence can cause localized pressure drops sufficient to form evaporation spaces or pockets downstream of the orifice constriction.

When the vapor bubbles that form in these spaces are collapsed by the pressure of the surrounding medium, the vapor is returned to the liquid.

This phenomenon is called cavitation, which results in sound generation and immersion of the surfaces of the valve structure adjacent to the cavitation.

It will be appreciated that in many applications it is desirable to substantially reduce both noise and cavitation effects during operation of the spool valve.

A similarly useful effect occurs when the frequency magnitude of the noise generated as a result of cavitation does not easily reach or be easily transmitted through surrounding structures. generated.

Many structures have been devised in an attempt to deal with the noise and vibrations that occur as a result of operating valves in high pressure systems.

Most of them include some form of diversion device that operates in various ways to split the flow into smaller streams.

An example of such a device consists of successive layers of fine reticulated material, which are placed in close contact and preferably soldered to prevent mechanical vibrations of the parts from occurring.

Another type of construction that has been used to some extent includes sintered metal adjustment plates or sleeves.

These two devices are characterized by the fact that their degree of quietening is insufficient, and in the case of sintered elements, the structure is not completely as designed, so the results are not completely predictable.
It is known that it is not suitable for severe applications for the following reasons.

Another type of structure conventionally used consists of a stack of discs with tortuous passageways etched into adjacent surfaces, thereby having multiple bends as a means of frictionally inhibiting flow across the stack. .

Provides a large number of individual flow paths.

Although this device generates very little noise, it has the disadvantage that performance changes due to viscosity that changes with temperature, since this device essentially relies on friction losses.

In view of the above-mentioned drawbacks, the present invention aims to suppress the noise and vibration that occur as a result of operating a valve in a high-pressure system, and to ensure that changes in viscosity due to changes in temperature have almost no effect on the overall flow characteristics. In order to achieve this objective, the configuration of the present invention is such that the structure is closed by a rigid structure consisting of a group of stacked annular flat aperture elements and walls having no through holes and which is disposed on both sides of the rigid structure. A sedation device comprising several meandering flow passages oriented in the radial direction is applied to a flow control device, and the throttling elements are provided on both sides of the rigid structure and are offset from each other in the radial direction. It has a plurality of partially overlapping chambers and a group of holes having a smaller cross-sectional area than the chambers and arranged in a radial direction, and one end of each hole in the group of holes is arranged in a radial direction and in one plane. The other end communicates in the radial direction with a chamber provided on the other surface, and a meandering flow passage is formed by the chamber and the group of small holes.

When fluid flows through the serpentine flow path, the sum of the pressure drops that occur as the fluid flows across the eyelets is essentially the pressure drop across the flow control device.

By configuring the present invention in this manner, the flow velocity flowing through the small hole group can be suppressed to such an extent that no noise or vibration occurs despite a large pressure drop.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The purpose of flow control valve 10, shown generally in FIG. 1, is to provide a desired flow rate independent of changes in pressure thereon.

Fluid from a fluid source is supplied to inlet passage 12 and valve member 1
Flow from 0 is provided to external utilization equipment through outlet conduit 14.

A stationary, generally cylindrical member 18 is secured within the large interior chamber 16 of the valve 10.

A hole 20 passes through the center of this member.

The side wall of the member 18 is provided with a number of radially and axially arranged small holes 22 communicating with the artificial passageway 12.

These small holes 22 communicate with the central hole 20 and also with the passageway 24 via the chamber 16.

Fluid within chamber 16 is supplied via passageway 26 to annulus 28 , chamber 30 , and passageway 32 leading to chamber 34 formed in part by bore 20 .

Spool valve 36, which is reciprocatable within bore 20, includes spool members 38, 40, and 42.

Spool member 38 is contacted by a spring 44 which urges spool valve 36 to the left.

A control valve member 46 contacts the spool member 42 .

This member 46 is positioned within the bore 20 and can be manually moved in the direction of the arrow in FIG. 1 by rotating a shaft 48 that is exposed to the outside and held in the desired position by a lock nut 50.

Liquid pressure within inlet passageway 12 is communicated through passageway 52 to annulus 54 .

From this annulus fluid pressure is transmitted to a plurality of radial passages 56.

Passage 56 is connected to chamber 60 via an axial passage 58 .

Fluid pressure within chamber 60 is applied to the end of spool 42 against the force of spring 44.

As the manually operable shaft 48 is rotated, the circumferential cut-out member 46 successively covers or uncovers the desired number of orifices 22.

Once member 46 has been rotated to the desired position to cover the required number of orifices 22, lock nut 50 is tightened to maintain member 46 in the desired radial position.

Fluid flowing through valve 10 flows through inlet passageway 12 and into chamber 16 through orifice 22 and passageway 24 .

From the chamber 16 it flows through a number of finely divided passages, represented in the figure by washer-like members 62, into the chamber formed in the bore 20 between the spool elements 3B and 40.

This chamber communicates with the outlet passage 14 via a conduit 64.

The orifice 22 allows the fluid pressure to be lowered in a controlled manner.

This pressure drop is the only pressure drop between passageway 12 and chamber 34.

The passages 52, 56, 58 only communicate with the chamber 60 and no flow velocity occurs except during transient movements of the spool valve 36.

Essentially, the fluid that maintains the pressure in the input section is the chamber 6.
0 and this fluid pressure forces the spool valve 36 to the right against the force of the spring 440.

Since the pressure applied to the reaction end of spool valve 38 is applied over essentially the same area, it can be seen that spool valve 36 moves to a position where the fluid pressure difference therebetween is balanced by the force of spring 44.

As shown, the spool valve 36 is in the farthest left position.

If there is a sufficient pressure drop downstream of outlet passage 14, this lower pressure will be transferred to chamber 34 and
The pressure within 0 causes the spool valve 36 to move to the right.

As the valve 36 moves to the right, it causes the spool member 40 to increasingly cover the finely divided orifice discharging fluid from the disc 62 into the chamber between the spool members 40 and 38. It will be done.

The valve 10 has a very high pressure difference (approximately 280 kg/crr*
), noise and vibration will occur unless a damping device such as the disk 62 is provided.

Using a silencing device such as disc 62, the structurally generated noise associated with this type of valve can be reduced to 10 KH2.
from over 130 db at frequencies up to over 80 db within this frequency range.

The valve described above is only one example of the application of the sedation device of the present invention.

This sedation device can also be used with servo valves such as those disclosed in U.S. Pat. No. 4,883,77 and U.S. Pat. No. 3,095,002.

FIG. 2 is an enlarged sectional view showing a portion of the flow path passing through the disk 62.

The disk group 62 consists of a continuous group of elements constructed as shown in FIG. 2, providing a detour around the elements.

Some disks 68 having elongated holes are inserted between each pair of solid disks 660, and one disk 70 having a relatively small diameter hole is inserted between the disks 68. Ru.

Fluid flow is confined between the solid discs 660 and 68
The fluid flows through a chamber 72 formed by the hole in the hole and the solid disk 66 and disk 70 .

The fluid then flows from the chamber 72 to the small hole 7 of the disc 70.
4 through the large chamber 76 in the reaction side disc 68
flows into the.

In this way, fluid flows from the chamber through the holes to other similar chambers, then turns around and flows through the next smaller hole into another large chamber 76, from the outside of the disc stack to the inside. It flows according to this flow pattern of flowing from the outside to the outside.

In the structure shown in FIG. 2, the frictional resistance within the elongate chambers 72, 76, etc. is so small that almost all the pressure drop occurs in the eyelet of the disc 70.

In the flow control valve 10 shown in FIG. 1, a plurality of disk groups shown in FIG. 2 are stacked as a unit and used.

FIG. 3 is a view showing the outer edges of some of the discs shown in FIG. 2, with cuts being made specifically in discs 68 and 70 to allow fluid to flow through the path described above. It shows how marks are placed to determine the correct orientation between each other.

Although other suitable landmarks may be used, the one shown in FIG. 3 has been found suitable for manufacture.

Figures 4 to 9 show disk 66.6B in different manufacturing operations.
, 68a, 70.

The disk 66 is a flat disk similar to the disk shown in FIG.
It has a large center hole and can be made to any desired size.

FIG. 4 is a plan view of a disk similar to the disk designated by reference numeral 68 in FIGS. 2 and 3, but because the holes are somewhat smaller, this disk is designated by the reference numeral 68a.

The disc 68a is bored with a pair of dumbbell-shaped holes extending from near the outer edge to near the inner edge.

FIG. 5 includes a plurality of small holes positioned between chambers formed within disk 68 or 68a.

FIG. 6 is a plan view of a disk similar to that shown in FIG. 4, except that the elongated holes have straight sides.

The rows of holes in this disc extend around the entire circumference of the disc, rather than in a small arc as shown.

Ru.

The disks shown in FIGS. 4, 5 and 6 have notches in their edges as described with reference to FIG.

When the discs 68 or 68a are assembled into a stack, the notches marking the position of the individual discs result in a continuous detour flow pattern as shown in FIG.

Once the disc stack is assembled to the desired length, the discs are secured to each other by brazing or other suitable means, exposing the outer edges of the eyelets as shown in Figures 7, 8 and 9. Scrape off the outer periphery of the disc and around the center hole until it is.

Once this process is performed, fluid can flow as shown in FIG.

Figures 10, 11 and 12 show an alternative disc pattern in which the fluid continues to flow in parallel through several holes.

The disc 80 has several holes 82, 84, 86, 88.

The size of these holes is such that they form a chamber with dimensions that span several groups of eyelets.

Disk 90 includes holes 92, 94, 96 that are radially displaced in the holes in disk 80.

Disk 100 is such that when disks 80, 90, and 100 are stacked, the flow pattern is inscribed with additional holes parallel to the holes shown for communicating fluid from one chamber to the other. It includes several groups of eyelets spaced apart so as to be essentially the same as the flow pattern shown in FIG.

Thus, flow entering holes 82 flows through the outer rows of swarms 102 into the chambers formed by holes 92 and through the inner rows of swarms 102 into the chambers formed by holes 84. Flowing in, then a horde 104
The fluid flows through the outer rows of , and so on.

Yet another embodiment is shown in FIG.

The concentrically arranged protrusions 116 extending from both sides of the disc 1100 are combined with the disc 66 of material,
Holes 114 form annular chambers that communicate with each other.

FIG. 14 is a cross-sectional view of an embodiment using disks 110 and 66, showing a flow pattern similar to that of FIG. 2, except that the chambers are annular.

The theory of operation of all the embodiments described above is essentially the same.

The noise generated by fluid flowing through a hole is a function of Reynolds number, and one of the factors in Reynolds number that has caused problems with similar devices is that it can vary significantly, making noise suppression performance variable. It is the viscosity of the fluid.

With the structure described above, which allows fluid to flow from a relatively large chamber through a small hole to another relatively large chamber, the flow rate of the fluid through the hole is selected by the hole diameter and the total pressure drop across the stack. The loss due to frictional resistance is also relatively small.

In this application, one operates to keep the Reynolds number in a range such that the hole modulus changes little.

As a result, there is also little change in flow characteristics as a function of changes in viscosity.

Additionally, the pressure difference applied by the present invention is very large;
A sedation device can be made for use in valves where changes in viscosity have little effect on the overall flow characteristics.

It is very useful that viscosity changes have little effect on the overall flow properties since viscosity changes are a factor that must be addressed due to temperature changes throughout the system.

To reduce noise to the desired level, the number and dimensions of the holes in series should be calculated such that the velocity of the fluid flowing through each hole should not exceed a value that does not result in an excessive Reynolds number. Based on this understanding, it will be clear to those skilled in the art that this can be done linearly.

By using a bell-shaped hole as shown in Figure 4,
Additional holes can be included in discs 70 and 68a so that the number of holes arranged in series is increased.

Since the Reynolds number is a function of hole diameter and fluid viscosity, it is also clear that the hole diameter can be adjusted to compensate for changes in fluid viscosity throughout this serial hole flow path.

This allows optimal use of the space within the throttle valve as each hole can be adjusted to provide the highest pressure drop within the desired noise level.

In addition to the effects of Reynolds number on the noise due to single holes, series holes, and series or parallel flow paths, high frequency throttling noise increases when any flow rate is only partially opened (short It has been recognized that the flow rate can be controlled by adjusting the speed of the fluid being constricted, depending on the length of the open channel, such as the measured length.

Therefore, given a flow path of constant impedance, what is the throttling speed for that flow path? ! It can be controlled by setting 1#.

High-frequency noise (above about 3KH2) can also be controlled by quiet flow in the wide open channel and by quiet throttling.

Low frequency noise is caused by the non-meterin valve flow path.
gvalve path) at a flow rate of approximately 4.6 to 6
．． It can be controlled by controlling to very low values of 1 m/sec (approximately 15-20 ft/sec) or less.

The main embodiments of the present invention will be listed below.

(1) The aperture element group consists of three flat discs 6B, 70°68
a; 80, 90, 100, of which two outer discs 68, 68a, 80°90 are small hole groups 74; 1
Central disk 70 with 02, 104, 106; 100
A number of chambers 72, 76; 82, 84, 8 communicating with
6° 88.92, 94, 96. A sedation device as claimed in the claims.

(2) One of the diaphragm element groups 110 has a plurality of concentric annular ridges 116 integrally formed on both sides, and the annular ridges formed on both sides are arranged in a function shifted from each other,
A sedation device as claimed in claim 1, characterized in that the chambers are defined between the annular ridges and the web of the aperture element 110 between the annular ridges is provided with eyelets 114.

(3) The sedation device described in the claims and each of the above items, wherein the wall body 66 having no through holes is constituted by a flat disk.

(4) The rigid structure 62, which is made up of a group of aperture elements made up of a plurality of stacked disks, is connected to the chamber 7, which is made up of elongated holes arranged according to a certain pattern.
2,76.82,84°86.88,92,94,96
a tenth disc group 68, 68a; 80, 90 including the first disc group i, and a second disc group 72 including the small hole group 74, 102, 104, 106 inserted between these two discs.
.
The sedation device according to item (1) above, characterized by comprising a group of discs 66.

(5) The first disc group 68, 68alO, 90 and the second disc group 70, 100 are provided with notches in order to correctly determine their positions in the radial direction.
The sedation device described in section 4).

(6) The sedation device according to item 4 or 5, wherein the elongated hole formed in the disk 68a of the first group of disks has a dumbbell shape.

(7) A series of small holes 74; 102, 104; 106
114 and its cross-sectional area are selected such that the Raynozzle number of any one of the small holes does not exceed a certain value equal to an allowable noise level. sedation device.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a spool-type valve using the present invention, Fig. 2 is a partial sectional view showing the flow path of the calming element used in Fig. 1, and Fig. 3 is a radial direction. FIG. 4 is a cross-sectional view of an element similar to FIG. 2 showing the elements used to ensure alignment; FIG. 5 is a plan view of the second group of quenching elements showing the hole pattern before final assembly and finishing; FIG. 6 is similar to FIG. 4 using a differently shaped passageway. 7 is a plan view of the device shown in FIG. 4 before and after finishing, FIG. 8 is a plan view of the device shown in FIG. 5 after finishing, and FIG. 9 is a plan view of the device shown in FIG. 6 after finishing. 10 is a plan view of a first damping element group of an additional embodiment with a somewhat different hole configuration; FIG.
0 is a plan view of the second element group that cooperates with the element in Fig. 0, Fig. 12 is a plan view of another second group element, Fig. 13 is a plan view of another element, and Fig. The second example using the shown element
It is a figure similar to the figure. 10... Valve, 22... Hole, 36...
... Spool valve, 62.66.68, 68a, 70,
80, 90° 100.110... Quiet disk, 82, 84° 86.88, 92, 94, 96, 11
4...hole.

Claims (1)

[Claims] 1 A group of annular and flat aperture elements is stacked to form one rigid structure 62, and walls 66 having no through holes are arranged on both sides of this structure to close the structure and radially extend the entire structure. In a sedation device for a flow control device constructed by stacking a plurality of units having several meandering flow passages oriented, the throttling element groups are provided on both sides of the rigid structure and radially directed. A number of chambers 72, 76 offset from each other and partially overlapping; 82, 84, 86, 88°92.94
, 96 and a group of small holes 74° 102, 104, 1 having a smaller cross-sectional area than the chamber and oriented in the radial direction.
06; 114, one end of each of the holes of the group of holes communicates radially with one of the chambers disposed on one side, and each of the holes communicates with one of the chambers disposed radially and on the other side. A sedation device for a flow control device, the pacification device being configured to communicate with one of the chambers, the chamber and the group of eyelets forming the tortuous flow path.