US 3730479 A
The present invention constitutes an adjustable fluid restrictor providing throttling means to reduce pressure of liquid or gaseous media through a process of adiabatic flow with friction in contrast to conventional orifice type throttling devices which utilize rapid acceleration and deceleration as primary means of energy conversion. Said adjustable fluid restrictor containing labyrinth-type restrictions which are adjusted by conventional actuating means and provide constant enthalpy pressure reduction at substantially constant velocity regardless of variations in flow area.
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Description (OCR text may contain errors)
United States Patent 1 1 1 3,730,479
Baumann 1 1 May 1, 1973  ADJUSTABLE FLUID RESTRICTOR Primary ExaminerHenry T. Klinksiek Att0rneyChittick, Pfund, Birch, Samuels & Gauthier  Assignee: Masoneilan International, Inc., Norwood, Mass- 57 ABSTRACT Filed: July 61 1971 The present invention constitutes an adjustable fluid  APPL 159,745 restrictor providing throttling means to reduce preso sure of liquid or gaseous media through a process of Forelgn Appllcatlon y Data adiabatic flow with friction in contrast to conventional July 6, France orifice type throttling devices utilize rapid ac- 52 U s c1 .251/121 celeratim and deceleration as Primary means 51 Int. Cl ..Fl6k 47/00 gY conversion Said adjustable fluid restrict  Field of Search ..251/120, 121, 122, labyrinth-type restrictions which are adjusted by 251/127, 209, 210; l37/625.34, 625,36 conventional actuating means and provide constant enthalpy pressure reduction at substantially constant  Reierences Cited velocity regardless of variations in flow area.
UNITED STATES PATENTS 12 Claims, 2 Drawing Figures 2,737,979 3/1956 Parker .L ..l37/625.34
4o 34 3 s 7 22 I 28 -30: 7
: 1o" V 1 2O 24M 21 25\ 1 27 ll l/ l 11 I 1 1 I I 1 l7 f r I f 8 35 I 44 i t x l 41 ADJUSTABLE FLUID RESTRICTOR BACKGROUND OF THE INVENTION Energy transported in fluid form has to be transformed quite frequently into a lower form of state (increased entropy) to suit process requirements. Such energy conversion is most common in the form of fluid pressure reduction. In a so-called throttling process potential energy of the fluid is transformed into kinetic energy (high velocity), then by a process of rapid deceleration (turbulence) into heat through friction. However, not all of the kinetic energy is converted into heat. A certain amount of it produces sound power, more commonly known as throttling noise. The amount of sound power produced in a fluid system is generally a function of the fluid velocity. It has been determined, for instance, that the sound level of a free jet increases to the 8th power of the velocity below Mach 1 (sonic velocity) and to the 6.5th power above Mach 1. In practice this means that the sound power produced by a single throttling orifice will increase 256 times, if the throttling velocity across it is doubled. Now, since the velocity in an orifice is a function of V 2gh where h is the created pressure drop, one can state that a 4-time increase in pressure drop could produce 256 times more noise. This simple arithmetic explains why high pressure reduction necessary in todays power plants can create intolerable noise levels in residential neighborhoods. Such noise can not only be annoying but also a vital factor in the successful operation of submarines. Noise produced through pressure reduction in the ship s power plant can lead to sonar detection with diastrous consequences. In addition, sound vibrations can cause structural damage to adjacent piping and pressure vessels.
From the foregoing it is obvious that a signficiant reduction in velocity is necessary to achieve a tolerable low noise level. With conventional plug and orifice valves such velocity reduction is only possible by employing a lower pressure drop, thereby seriously limiting the usefulness of such a device.
Besides the obvious high throttling noise level, there is the added effect of wear. Conventional throttling orifice valves, for instance, show substantial effects of erosion at or near the plug and orifice, when subjected to high pressure drop. Again, the higher the pressure drop the more pronounced the wear and the shorter the lifetime of the valve.
FIELD OF THE INVENTION This invention relates to adjustable fluid restrictor devices such as shown and described in my prior U.S. Pat. No. 3,485,474, and providing a throttling series affording successive friction losses primarily through tortuous turns of a fluid under pressure, so as to limit the speed of throttling of that fluid to a value assuring a low and, in any case, acceptable level of the throttling noise; and also preventing quick wear, by the effects of cavitation, of the throttling elements of the device.
In general, a fluid restrictor, or throttling device such as here concerned, has comprised:
A housing internally provided with concentric rings axially spaced from one another;
A moving stem, mounted coaxially in regard to said rings and presenting radially projecting circular discs, arranged or spaced intermediate or in alternation with the rings, and so as to cooperate therewith; and
Some means of axial adjustment of the stem whereby to regulate the spacing between the rings and the discs.
The rings and discs of such throttling device provide radially spaced, axially directed passages for fluid flow, and radial flow passages connecting said axially directed passages in an annular labyrinth presenting adjustable restrictions by which is accomplished, through successive throttlings, that is, pressure reduction through a series of sharp turns of fluid under pressure.
Such fluid restrictor additionally affords successive throttlings independently of the flow variations of the fluid under pressure, and requires only relatively small movements of the stem discs in relation to the cage rings, to accomplish the needed adjustment of the restrictions of the labyrinth.
BRIEF SUMMARY OF THE INVENTION In accordance with the present invention, a fluid restrictor or throttling device of the type described in my prior U.S. Pat. No. 3,485,474, and characterized generally by concentric rings and discs, is utilized for the expansion, in two flows, of a compressible fluid, or gas, under pressure.
Increase in flow area between successive stages allows compensation for density changes of a passing gas while gradually reducing in pressure.
Finally, static balance of fluid forces is achieved by splitting the flow through two nearly equal throttling elements.
BRIEF DESCRIPTION OF THE DRAWINGS In the annexed drawings:
FIG. 1 is a vertical or axial section of a throttling device in accordance with the invention; and
FIG. 2 is a fragmentary or detail view on a larger scale of a gas-adapted form of the improved seat ring and plug construction of the present invention.
DETAILED DESCRIPTION OF THE INVENTION A conventional, double flow valve housing or body 8 has a herein flanged inlet chamber 9, a laterally aligned outlet chamber 10, and therebetween an intermediate wall or partition 1 1 formed and apertured to define vertically aligned, upper and lower valve seat openings 12, 13 from said inlet chamber 9 to the two divided flow ducts 14, 15 discharging to outlet chamber 10, the latter flanged or otherwise formed similarly as inlet chamber 9 for coupling into a pressure fluid line for left-to-right flow therethrough.
,In accordance with the invention, there are provided at the openings l2, l3 annular cage means, shells, or seat rings 16, 17 threaded or otherwise received through said openings 12, 13, and stopped thereagainst as at external shoulders 18, 19. The upper and lower cage means or seat rings 16, 17 areinteriorly formed with radially inwardly projecting, annular inlet end ridges 20, 21, and therebeyond with as many radially inwardly projecting, annular, axially spaced ribs or ridges 22, 23 as there are to be throttling stages.
The fluid restrictor hereof further has a moving stem comprising a pair of cylindrical, coaxial, integral or interdependently coupled upper and lower plugs 24, 25 mounting annular, radially projecting rings or discs, said circular, upper and lower plug discs comprising the inlet end discs 26, 27 cooperating with the seat ring inlet end ridges 20, 21, and axially spaced upwardly and downwardly therefrom the throttling discs 28, 29 cooperating or functioning with the corresponding or juxtaposed seat ring throttling ridges 22, 23.
Within the invention, the ring ridges -23 and plug discs 26-29 may be generally conical or tapering, as herein shown, or they may be variously formed as in my prior U.S. Pat. No. 3,485,474, or otherwise.
For shutting off the flows through both discharge ducts 14, 15, inlet end plug discs 26, 27 are larger than, and spaced similarly from and on the same (herein lower) side of, the seat ring inlet end ridges 20, 21. Further, for convenient assembly from (herein) below of the plug means 24, within the housing 8 and seat rings 16, 17 as inserted therein, the upper plug inlet end disc 26 is made smaller than the lower ring inlet ridge 21.
The upper plug throttling discs 28 are, of course, smaller than lower and upper ring ridges 23, 21, 22, 20; and the lower plug throttling discs 29 are smaller than lower ring ridges 23. The spacing of the stem plug discs 2629 below the seat ring ridges 20-23 may be identical, as well may be the spacing between the upper and lower axial, ring and plug portions 30, 31, 32, 33 intermediate the said ridges and discs thereof.
The moving stem plugs 24, 25 further comprise upwardly and downwardly extending, reduced annular guides 34, 35 having a sliding, centering fit within bore passages 36, 37 formed in covers 38, 39 closing as conventionally the top and bottom openings 40, 41 provided as conventionally in the housing 8a for insertion therethrough of the heretofore described restrictor cage ring and stem plug means.
The invention plug means 24, 25 may be reciprocated for regulating or variously limiting the pressure fluid flows by a stem 42 coupled in any wise thereto, and extending upwardly through top cover 38 for the indicated axial manipulation by conventional actuator means. The aforementioned cover bore passages are defined behind the guides 34, 35 as balancing or equilibrium chambers 36, 37 by holes or passages 43, 44 admitting to discharge passages 14, 15.
In the FIG. 1 embodiment, then, the restrictor hereof is seen to define radial reversing, or sharp angular bending, throttling passages formed by the opposed, parallel tapered ridges 20-23 and discs 26-29; by the axial ring portions 30, 31 opposing plug discs 26, 28; 27, 29; and by the axial plug portions 32, 33 opposing the ring ridges 20, 22; 21, 23. Also as more fully described in my prior US. Pat. No. 3,485,474, the upward movement of stem 42 and plugs 24, 25 from the position of the drawing is to narrow the width, and reduce the area, of the aforesaid passages, and thereby to additionally restrict the two flows through the openings 12, 13.
It will be understood that the stern plug disc and seat ring ridge couples are adaptable to the variations of specific volume of a compressible fluid under pressure, that result from the expansion of such fluid. Also that the spaces between the discs and ridges may be calculated to take into consideration the variations of the specific weights of the compressible fluids, such as steam under pressure, this to accomplish, during the expansion of those fluids, the preventing of throttling noise and of the effects of accelerated wear; the successive restrictions by the throttling zones of the invention device assuring a distribution of pressure drops well adapted to such results.
Further, with the same actuator stem 42, the relative positions of the stem plug discs and seat ring ridges may be variously modified, within the scope of theinvention, and depending upon the flow values of the fluid, without disaffecting the results to be achieved by the device.
To compensate for density changes in the successive throttling stages, provision is made, in the FIG. 2 form of the device adapted for gaseous media, for successive enlargement of the flow area used to reduce fluid pressure.
In FIG. 2 the intermediate partition wall is shown at 45, the upper and lower seat rings generally at 46, 47 and the upper and lower valve plugs at 48, 49.
In accordance with the invention, successive enlargements of the flow area in the successive throttling stages are achieved by successively increasing or sharpening the upper and lower face angles of the upper and lower plug discs 50, 52a, 52b, 52c; 51, 53a, 53b, 53c," and similarly the upper and lower face angles of the ring ridges 54, 56a, 56b, 56c; 55, 57a, 57b, 570. The spacing of the plug discs and ring ridges being otherwise unchanged from their equal increments along the axis of the throttling device, it will be understood that the effective spacing for the fluid passing between plug and seat ring as thus defined is the product of the cosines of the said upper and lower face angles of the discs and ridges, times the axial spacing between the said discs and ridges at a given lift position.
Further, a similar distribution, or like successive enlargement of the flow area, may be accomplished between the plugs or discs and rings in the lateral direction. This is accomplished by successively decreasing the diameter of the disc-intervening cylindrical plug wall portions 58a, 58b, 58c; 59a, 59b, 59c, and by similarly successively increasing the diameter of the ridge intervening, cylindrical ring wall portions 60a, 60b, 600; 61a, 61b, 61c. I
It will be appreciated that in the embodiments hereof the invention restrictor is susceptible of ready assembly and disassembly in the manner described, with (referring to FIG. 1) the rings 16, 17 first being inserted to engage at their shoulders 18, 19 the openings 12, 13, with the plugs 24, 25 then being inserted to the position of the drawings, and with the covers 38, 39 then being installed over the guides 34, 35 and to seal the openings 40, 41 in the usual manner.
Those skilled in the art will also appreciate that, to adapt a conventional double flow valve to receive the rings 16, 17, only a slight modification of the openings l2, 13, from their conventional configuration to that herein shown, is required.
1. An adjustable fluid restrictor comprising a. a valve housing;
b. lateral pressure fluid inletting means comprising an inlet chamber and opening;
c. lateral pressure fluid outletting means comprising two flow ducts and a communicating outlet chamber and opening;
d. an intermediate housing wall partitioning said inlet chamber from said ducts;
e. upper and lower, vertically aligned annular openings through said intermediate housing wall;
f. top and bottom access openings through said housing, said access openings larger than, and over and under, said intermediate wall openings;
g. upper and lower cage ring means seated through said intermediate wall openings;
h. upper and lower stem plug means coaxially arranged within and for vertical reciprocation relative to said cage ring means;
i. upper and lower housing covers closing said access openings;
j. bearing formations in said covers for sliding, centering engagement by said plug means; and
k. concentric, juxtaposed, annular, radially inwardly and outwardly projecting ridges and discs formed on said ring and plug means, said ridges and discs defining with the axial ring and plug portions intermediate therebetween a succession of sharp angular bends through which may be conducted two expansion flows of pressure fluid from said inlet to said outlet chamber.
2. Adjustable fluid restrictor of claim 1 wherein the lowermost upper plug disc is below the lowermost upper ring ridge, wherein the uppermost lower plug disc is below the uppermost lower ring ridge, and wherein said disc and ridge couples are of overlapping diameter whereby upon reciprocation of said plug means to close said couples together said upper and lower ducts may be closed to said pressure fluid.
3. A adjustable fluid restrictor of claim 2, wherein the disc of one is smaller than the ridge of the other of said couples, whereby the device may be assembled by installing said ring means through said intermediate,
housing wall openings, and then inserting said plug means through one of said housing access openings.
4. The adjustable fluid restrictor of claim 1, wherein said plug means comprise cylindrical guides for engaging in said cover bearing formations, and wherein said bearing formations comprise recesses extending beyond said guides within said covers, said beyond-extending recesses ported to said outletting ducts whereby to define equilibrium chambers.
5. Adjustable fluid restrictor of claim 2, wherein the spacing of said disc and ridge couples is equal whereby the two expansions flows of pressure fluid are simultaneously closed and opened thereby.
6. Adjustable fluid restrictor of claim 1, wherein saidring and plug ridges and discs define radially reversing pressure fluid flow passages, and wherein said plug means comprise a stem extending without said housing for reciprocation by actuator means, whereby to vary the axial distance between said ridges and discs, and thus to regulate the width and area of said flow passages.
7. Adjustable fluid restrictor as set forth in claim 1, wherein the proportioning of and spacing between the upper and lower ring and plug means ridges and discs in so correlated as to order substantially equal flows of said pressure fluids therethrough.
8. Adjustable fluid restrictor as set forth in claim 1, wherein the discs of said upper and lower plugs means are positioned correspondingly above or below the similarly spaced ridges of said upper and lower ring means, and wherein said upper and lower plug and ring means define intermediate said ridges and l'lbS uxtaposed cylindrical surface areas across which the pressure fluid is axially flowed intermediate the radial passages defined by said ridge and disc means.
9. Adjustable fluid restrictor as set forth in claim 1, wherein the upper and lower faces of the upper and lower plug discs are, from the inlet ends of the plugs, of progressively steeper angle, thereby having progressively greater spacing from the juxtaposed ring ridges.
10. Adjustable fluid restrictor as set forth in claim 1, wherein the upper and lower faces of the ring ridges are, from the inlet ends of the rings, of progressively steeper angle, thereby having progressively greater spacing from the juxtaposed plug discs.
11. Adjustable fluid restrictor as set forth in claim 1, wherein said sleeve rings comprise cylindrical portions intervening between said ridges, and wherein said cylindrical portions are, from the inlet ends of said rings, of progressively increasing diameter, thereby havingprogressively greater lateral spacing from the opposing plug portions.
12. Adjustable fluid restrictor as set forth in claim 1, wherein said stern plugs comprise cylindrical portions intervening between said discs, and wherein said cylindrical portions are, from the inlet ends of said plugs, of progressively decreasing diameter thereby having progressively greater lateral spacing from the opposing ring portions.