The present invention may be concentrated to a fluid flowing resistor, a back pressure control part and other parts, and can be applied to a multi-orifice type valve, a multi-path type valve, or any fluid flowing control and shut-off device which is similar thereto.

Background Art Conventionally, the devices, which are related to valves and resistors, are applied in substantially wide range of fields, in which some are commonly called'multi-path type valve'.

Specifically, a conventional multi-path type valve is applied in an ultimate situation or in a field where a high degree of precision should be required.

Moreover, the velocity control for fluid can be achieved in the multi-path type valve, and therefore, the valve can be applied in all devices where a long life period and a good quality of performance of the valve should be satisfied.

The conventional multi-path type valve can be applied in the fields where noise and cavitation are controlled or in a high precision of control field where hydraulic fluid or non-hydraulic fluid is adjusted. In addition, the valve is applied in various industrial fields containing thermal power generation, nuclear power generation, petrochemical production, refinement and various chemical process

and so on.

A fluid flowing resistor of the conventional multi-path type valve, which is applied in the various fields as discussed above, is based upon a series of discs or cylinders which are stacked or overlapped one another.

Each disc or cylinder has a plurality of separated paths and tortuous paths formed thereon, each of which is adapted to control pressure or an amount of fluid flow of the devices over the whole length of the valve. The details of devices concerning the above mentioned can be shown on US Pat. No. 4921014, US Pat.

No. 4567915, US Pat. No. 4407327 and US Pat. No. 4105048.

The fluid passing through the tortuous paths experiences velocity head loss.

The discharging velocity is kept to be decreased such that the resistance created in the fluid flowing path under the certain state prevents the cavitation, corrosion, abrasion, noise and vibration generated due to the fluid flow to be suppressed.

The conventional multi-path type of valve and fluid flow resistor are characterized in that the internal disc or cylinder forms a directional path and a winding turn type path thereon.

A plug is adapted to move up and down on the inside of the conventional cage and has the leading end for opening/closing the fluid flowing paths of the fluid flowing resistor to adjust the overall flow of the fluid passing through the valve and for sealing the flow of the fluid, while being in contact with a seat.

In any case, for the purpose of performing the up and down movement of the plug in a stable manner and contacting the plug with the seat in a concentric axis, a labyrinth plug is used, which has a plurality of circumferential grooves which are formed on the side surface of the lower portion of the plug.

As mentioned above, in the conventional cage for use in a valve, the size of the cage becomes bulky because of small fluid flowing path and simple tortuous path formation for generation of a required amount of velocity head loss.

Moreover, this yields the following problems ; a) the total size of

the valve becomes large ; b) the whole materials required for the valve are added ; and c) the installation space of the valve is enlarged.

In addition, the sealing portion of the plug generates a vena contracta phenomenon caused by an orifice principle on an adjacent position on which the sealing portion thereof has a clearance with the fluid flowing path of the fluid flowing resistor having a high pressure ratio or with the seat, so that the cavitation, flashing, erosion/corrosion, noise and vibration caused due to velocity increment of fluid flow and decrement of the pressure occur on the fluid flowing resistor, plug, seat and the like.

In the same manner as the above, these phenomena occur even on the labyrinth plug.

On the other hand, since the cage is comprised of a plurality of fluid flowing paths each having a small sectional area so as to generate the desired amount of velocity head loss, if foreign materials are inserted into the inlet of the valve, the paths of the cage or the inlet thereof is blocked to thereby deteriorate the inherent performance of the valve. Meanwhile, in the valve where the fluid passes through the cage from the lower portion of the plug, the sealing portion of the leading end of the plug, which is moved in an axial direction, is damaged due to the foreign materials blocked up the inlet of the path of the cage, to drastically deteriorate the sealing function of the valve.

In this case, so as to filter the foreign materials inserted into the inlet of the valve, a separate screen is attached on the inlet for flowing the fluid to the valve.

Disclosure of Invention An object of the present invention is to provide a fluid flowing control device of a valve which can be assembled and fabricated in easy and simple manner, while retaining characteristics of a cage of a multi-path type valve, and can allow the fluid flowing resistor as a cage to restrict the insertion of foreign materials and form a predetermined space between a plug and the fluid flowing resistor, to thereby prevent the fluid flowing resistor from being blocked by the

foreign materials as well as prevent the interaction of the foreign materials with the plug, without having a separate screen on the inlet for flowing the fluid on the valve.

Another object of the present invention is to provide a fluid flowing control device of a valve which can generate a large amount of velocity head loss on a plurality of fluid flowing paths to thereby increase a sectional area per the fluid flowing path on the constant differential pressure conditions applied to the valve, whereby the fluid flowing path is not blocked by the foreign materials passing through the valve to thereby increase an amount of the fluid flow within a predetermined volume thereof.

Still another object of the present invention is to provide a fluid flowing control device of a valve which can perform a structural function separation and fluid flowing dispersion in a device which interacts with the fluid flow to thereby prevent a vena contracta phenomenon on an adjacent position to a fluid flowing stop position where a high pressure difference is generated, whereby cavitation, flashing, erosion/corrosion, noise and vibration can not be generated on a fluid flowing resistor, plug and seat.

To achieve these and other objects according to the present invention, a fluid flowing control device of a valve having a body comprised of a fluid inlet and a fluid outlet, a plug moved between the fluid inlet and the fluid outlet to control fluid flow, and a cage having a plurality of holes and grooves, the plug being closely attached and moved on the inside of the cage, includes: the cage having an inside cylinder which is closely contacted with the plug and forms a plurality of holes and protrusions in axial and radius directions, respectively, an outside cylinder which forms a plurality of holes in axial and radius directions, respectively, a first internal cylinder which is overlapped and coupled between the inside and outside cylinders and forms a plurality of concave/convex grooves having rectangular sectional elbows with recess in an axial direction and forming a plurality of holes thereon, a second internal cylinder which is coupled with the first internal cylinder and forms a plurality of holes in axial and radial directions, and upper and lower

supporting plates for closely coupling the inside and outside cylinders with the first and second internal cylinders on the top and bottom ends thereof; the plug forming a sealing portion and an opening/closing portion which are each in contact with a seat, on the leading end of the lower portion thereof and a plurality of holes connected to the opening/closing portion through a groove on the top portion of the opening/closing portion, to thereby open/close the seat and control the fluid flow, while being moved in the inside of the cage ; and the seat being in internal-contact with the plug.

Brief Description of Drawings These and other advantages, features and objects of the present invention will become apparent from the following detailed description of the preferred embodiment of the present invention with reference to the accompanying drawings, in which: FIG. 1 is a partial sectional view illustrating a valve in which fluid flow is controlled according to a first embodiment of the present invention ; FIG. 2 is a partial sectional view illustrating the valve of FIG.

1, in which a cylindrical cage is installed ; FIG. 3 is a partial sectional view illustrating the arrangement of the cage of FIG. 2; FIG. 4 is a perspective view illustrating an inside cylinder of the cage of FIG. 2; FIG. 5 is a partial sectional view illustrating an inside cylinder having concave/convex grooves of the cage of FIG. 2; FIG. 6 is a perspective view illustrating an outside cylinder of the cage of FIG. 2; FIG. 7 is a partial sectional view illustrating one formation and arrangement of the inside cylinder of the cage of FIG. 2 ; FIG. 8 is a partial sectional view illustrating another formation and arrangement of the inside cylinder of the cage of FIG. 2 ; FIGS. 9A and 9B are partial sectional views illustrating yet another formation and arrangement of the inside cylinder of the cage of FIG. 2 ;

FIG. 10 is a sectional view illustrating the assembling state of the inside cylinder with the outside cylinder of the cage of FIG. 2 ; FIG. 11 is a sectional view illustrating a valve in which fluid flow is controlled according to a second embodiment of the present invention, in which disc type column is installed ; FIG. 12 is a partial plan view illustrating a pair of discs of the disc type column of FIG. 11 ; FIG. 13 is a partial perspective view illustrating the pair of discs of FIG. 11 ; FIG. 14A is a partial plan view illustrating a fluid flowing path of one disc of the disc type column of FIG. 11 ; FIG. 14B is a partial sectional view illustrating an operational process of FIG. 14A ; FIGS. 15A to 15C are partial sectional and side views illustrating the pair of discs of the disc type column of FIG. 11 ; FIGS. 16A to 16D are partial sectional views illustrating the valve of FIG. 1, in which a function separation type plug and a seat are installed ; FIGS. 17A and 17B are partial sectional views illustrating the function separation type plug and the seat of FIGS. 16A to 16C on which protrusion and groove are respectively formed ; and FIG. 18 is a partial sectional view illustrating a fluid flow control device of a valve according to a third embodiment of the present invention, where a fluid flowing resistor and a seat are integrated with each other.

Best Mode for Carrying Out the Invention The fluid flowing resistor of the present invention is configured based upon a cylinder or a disc, and a resistant portion of each fluid flowing path is constituted by combining orifice, rectangular section elbow with recess so as to produce a high amount of velocity head loss.

The rectangular section elbow of the present invention has different inlet and outlet sectional areas, which is intended to generate a high amount of velocity head loss relative to the fluid

flow.

An amount of pressure drop generated through the fluid flowing path is proportional to loss coefficient, density of fluid and square of velocity which are determined upon the shape of fluid flowing path of the resistant portion and Reynolds number.

Since the amount of pressure drop is determined in accordance with the operational conditions of the valve, if the total velocity head loss is increased, the velocity of fluid can be effectively controlled in a smooth manner. The more the number of the resistant portions is increased by the fluid flowing path, the less the sectional area of the fluid flowing path is occupied, or the higher the loss coefficient of the resistant portion is, the greater the total amount of velocity head loss becomes.

Therefore, if the number of the resistant portions is increased and the sectional area of the fluid flowing path is reduced, the size of the fluid flowing resistor is bulky or an appropriate amount of fluid to be passed through the valve can not be obtained. To the contrary, if the sectional area of the fluid flowing path is increased, the size of the fluid flowing resistor is bulky, thus making it difficult to adjust the velocity of fluid and cavitation.

Based upon the flow characteristic of the fluid, the present invention includes the resistant portion of each fluid flowing path which is designed to have a high loss coefficient, to thereby obtain a predetermined amount of pressure drop and velocity during the fluid flow, and is increased in number within a predetermined volume of the fluid flowing resistor, to thereby enlarge the sectional area of the fluid flowing path at the predetermined amount of pressure drop of the valve.

In accordance with the flowing and structural characteristics of the resistant portion, the cylindrical fluid flowing resistor of the present invention has the fluid flowing paths which are divided in the axial direction of the plug and has a clearance by the formation of orifices and rectangular section elbows with recess to control the fluid flow. This can avoid a separate operation for the arrangement of the orifices and the elbows. Therefore, the present invention can produce

and use a low-priced, but very precise valve, without having a conventional expensive multi-path type valve.

On the other hand, the disc type of fluid flowing resistor of the present invention has a pair of discs which are manufactured by combining orifices, rectangular section elbows and elbows with recess so as to increase a sectional area thereof relative to the flow direction of the fluid flowing path, so that the fluid flow is formed in radius and axial directions to utilize to a maximum extent the available volume of the fluid flowing resistor.

Of course, the fluid flowing paths are formed through a plurality of discs, or the fluid flowing path similar thereto is formed through a single disc, in a radius direction thereof.

The fluid flowing resistor of the present invention may make the arrangement of the resistant portions and the size of the sectional areas of the fluid flowing paths substantially different from each other, which can of course combined and exchanged with each other.

The thickness of the cylinder or disc of the fluid flowing resistor and the size of groove thereof are dependent upon the fluid conditions.

The thickness of the thinnest section of the resistor is determined in a stable manner in respect of the structure or working, and the stability of the thickness thereof is checked with a structural interpretation.

The fluid flowing resistor of the present invention has a plurality of holes, grooves or structural protrusions on the fluid inlet which are equal/slight less to and than the size of the fluid flowing path of the interior thereof and is adapted to substantially enlarge the sectional area of the fluid flowing path, thus to prevent the fluid flowing resistor from being blocked by the foreign materials within the fluid.

Preferably, a function separation type plug of the present invention has a sealing portion which is in contact with the seat and an opening/closing portion of the fluid flowing path of the fluid flowing resistor, for the purpose of performing function separation, and forms a plurality of grooves and holes on the surface of the

upper portion of the opening/closing portion to generate pressure dispersion and back pressure by the fluid flow, thereby preventing the associated parts thereto from being damaged due to the fluid flow.

The structural function separation of the plug can prevent the fluid flowing velocity when the fluid flows between the lower portion of the plug and the seat from being high.

In addition, the plug forms a fluid flowing path which traverses the groove in the circumferential direction and the opening/closing portion of the fluid flowing path, on the surface of the upper portion of the opening/closing portion, and if the opening/closing portion forms a minute fluid flowing path under a high pressure difference, disperses the fluid flow generated in the formed path or maintains the back pressure, so that the velocity of the fluid flow can not be high to thereby prevent the generation of the cavitation or the damage of the parts.

The present invention applies a velocity head loss generation structure in the cage which is made by integrating the fluid flowing resistor with the seat and the function separation type plug, whereby it can be manufactured with a simple process and upon formation of the minute fluid flowing path, the fluid flow can be controlled by steps in an appropriate manner.

With the simple device in the sophisticated structure, the velocity head loss is added and subtracted, the fluid pressure dispersion is made, or the back pressure is maintained, whereby the increment of the fluid flowing velocity can be removed at a specific portion, the cavitation and noise can be reduced, and a relative large amount of fluid can flow.

Moreover, the valve of the present invention may be an atmospheric resistor, flow valve, back pressure control valve, pressure reducer, pressure balancing or non-balancing valve, valve having a hard or soft seat and so on, for use in various kinds of fluids, and the function separation type plug for sealing the fluid flow may be applied to a pressure relief valve, a safety valve or other types of valve, so that fluid overflow on an adjacent position to the closing position of the sealing portion can be prevented to thereby avoid the

damage of the associated parts.

Now, an explanation of the construction of a fluid flowing control device of a valve according to a first embodiment of the present invention will be in detail discussed with reference to FIG. 1.

FIG. 1 is a partial sectional view illustrating a valve in which fluid flow is controlled according to the present invention. A general valve 5 is comprised of bonnet 6, plug 7, a body 8, stem 10 where a predetermined control is necessary.

The present invention is directed to cage 3, plug 7 and seat 9, which are respectively installed on a fluid flowing path between a fluid inlet 1 and a fluid outlet 2, for controlling the fluid flow.

The valve 5 controls a predetermined amount of fluid flow in accordance with the position of the plug 7 relative to the cage 3 and the seat 9 and has a fluid flowing path from the fluid inlet 1 to the fluid outlet 2 and contrarily another fluid flowing path from the fluid outlet 2 to the fluid inlet 1.

The valve 5 couples the cage 3 as the fluid flowing resistor 4 and the seat 9 in the interior thereof and the plug 7 moves between the cage 3 and the seat 9 to open/close the fluid flowing path formed between the fluid inlet 1 and the fluid outlet 2, thereby controlling the fluid flow.

Typically, in this case, the cage 3 is in contacted with the bonnet 6 on the seat 9.

The plug 7, which is disposed on the upper and lower centering line of the valve 5, is divided into left and right portions as shown in FIG. 1. The left portion of the plug 7 shows the case where the plug 7 is in contact with the seat 9 to completely close the fluid flow, and the right portion thereof shows the case where the plug 7 moves to the upper portion of the fluid flowing resistor 4 to open the fluid flow.

It is general that non-compressive fluid such as liquid or the fluid containing foreign materials flows over the plug 7 to thereby prevent the blocking of the cage 3 and the damage of the contact portion of the seat 9.

Compressive fluid containing vapour flows under the plug 7 to

thereby exhibit various advantages according to the fluid characteristic.

The cage 3 of the present invention is preferably the fluid flowing resistor 4, which takes a cylinder or disc shape.

The valve 5 is configured to pass the fluid through the cage 3 and flow the fluid to the lower portion of the plug 7, and also constructed to pass the fluid from the lower portion of the plug 7 toward the cage 3. Even in case of having different fluid flowing directions, the resistance value applied when the fluid passes through the cage 3 is same as each other.

Hereinafter, an explanation of the construction of the cage 3 as the cylindrical fluid flowing resistor 4 will be discussed with reference to FIG. 2.

FIG. 2 is a partial sectional view illustrating the valve of FIG.

1, in which the cylindrical cage 3 is assembled with the seat 9 and the plug 7.

The cylindrical cage 3 is comprised of an inside cylinder 25 surrounding the plug 7, an outside cylinder 22, first and second internal cylinders 23 and 24 which are overlapped and installed between the inside and outside cylinders 25 and 22, and upper and lower supporting plates 21 and 26 on the top and bottom ends of the cylinders 22 to 25.

The terminating ends of the top and bottom portions of the inside cylinder 25 are closely coupled to circumferential protrusions 29 and 30 of the disc shape of upper and lower supporting plates 21 and 26.

The outside and inside cylinders 22 and 25 and the first and second internal cylinders 23 and 24 installed between the outside and inside cylinders 22 and 25 form a plurality of holes 28 thereon, in which the first internal cylinder 23 forms a plurality of concave/convex grooves 27 having holes 28 the second internal cylinder 24 forms a plurality of holes 28, which are in turn overlapped and inserted between the outside and inside cylinders 22 and 25.

The circular holes 28 on each of the cylinders 22 to 25 may be replaced with longitudinal holes 52 or used together with the

longitudinal holes 52, as shown in FIG. 4.

The concave/convex grooves 27 of the first internal cylinder 23 are adapted to form a rectangular section elbow type path to flow the fluid in an axial direction or to help the fluid passing through the holes 28 to form or disperse the irregular flow.

Referring to FIG. 3, the size of each fluid flowing path hole 28 on the outside and inside cylinders 22 and 25 into which the fluid flows are designed to smaller or equal than/to the size of each fluid flowing path hole 28 of other cylinders, and the distance length 32 and 33 between the side of the hole 28 and the concave/convex groove 27, and the distance length 34 of the rectangular section elbow 31 path, thus preventing the fluid flowing path within the cage 3 from being blocked by means of the foreign materials of the fluid.

The cylindrical material of the cage 3 can be manufactured in simple and rapid manner with a cutting process by means of a conventional machine tool such as a lathe, a milling machine, a drill machine and the like. A separate operation which is required for the arrangement of the fluid flowing paths, for example, in a multiple drilled hole cage, a hush trim, etc. can be omitted in the cylindrical cage 3 of the present invention.

On the other hand, the fluid flowing paths are divided in the axial direction and resistant portions are formed to generate a large amount of velocity head loss, so that a precise control capability for the fluid is obtained and the cavitation and noise can be prevented on high differential pressure conditions applied to the valve 5.

The terminating ends of the upper and lower portions of each cylinder 22 to 25 of the cage 3 are closely coupled with the circumferential protrusions 29 and 30 of the disc shape of supporting plates 21 and 26 or the outside cylinder 22 and the inside cylinder 25 as shown in FIG. 10, or alternatively, may be bonded therewith by means of braze welding or laser welding in accordance with the specific conditions of the valve 5.

FIG. 3 is a partial sectional view illustrating the arrangement of the cage 3 as the fluid flowing resistor 4 of FIG. 2, in which the fluid flows by means of the hole 28 and the concave/convex groove 27.

Now, an explanation of the flow characteristic at each resistant portion will be in detail given hereinafter.

The fluid, which has pass the cage 3, generates velocity head loss as passes the hole 28.

The flow of fluid is divided by means of the rectangular section elbow (the rectangular direction) 31, and at this time, the divided flows have newly changed fluid flow sectional areas 32 and 35. Whenever the flow of fluid is bent in the rectangular direction, velocity head loss occurs.

Thereafter, the fluid passes through each hole 28 of the first internal cylinder 23 and is then bent by means of the rectangular section elbow 31. Next, the fluid is bent in the rectangular direction on the inlet of the ejecting hole 28 and then passes through the hole 28.

Above all, the loss coefficient of the rectangular section elbow 31 has a relation to the sectional area of the fluid inlet (the sectional area of the fluid flowing direction in the interval 32 between the hole 28 and the rectangular section elbow 31 or the sectional area 36 of the fluid flowing direction before the fluid passes through the hole 28 of the concave/convex groove 27, is dispersed and is bent in the rectangular direction) and the sectional area of the fluid outlet (the rectangular sectional area 35 of the fluid flowing direction before the fluid passes through the hole 28 of the concave/convex groove 27 or the sectional area of the fluid flowing direction in the interval 33 between the hole 28 and the rectangular section elbow 31). The less sectional area of the outlet 33 comparing with the sectional area of inlet 36, the more loss coefficient value of the rectangular section elbow 31 reveals exponentially.

Accordingly, when comparing with the arrangement where the same size of the inlet and outlet sectional areas of the rectangular section elbow 31 are repeatedly disposed, the arrangement of the present invention where the rectangular section elbow 31 having the outlet sectional area 35 larger than the inlet sectional area thereof is firstly disposed and the rectangular section elbow 31 having the outlet sectional area 33 smaller than the inlet sectional area thereof is then

disposed, causes the total loss coefficient of the rectangular section elbow 31 to be increased drastically.

As discussed above, the sectional area of the fluid flowing path is enlarged under predetermined pressure drop conditions. This yields various advantages in overall valve structure.

FIG. 4 is a perspective view illustrating the inside cylinder 25 of the cage 3 which is in contact with the plug 7 of FIG. 2. The inside cylinder 25 forms a plurality of circumferential protrusions 51 on the inside surface thereof by a predetermined interval in axial and radius directions and a plurality of holes 28 between the protrusions 51, through which the fluid flows.

The plurality of holes circular 28 may be replaced with the longitudinal holes 52 or may be used together with the longitudinal holes 52.

The circumferential protrusions 51 function as the labyrinth parts, while being in contact with the plug 7.

In addition, if the contact area of the protrusions 51 with the plug 7 is small, as shown in FIGS. 15A and 15B, the fluid flowing path can be smoothly opened/closed as the plug 7 moves in the axial direction.

Before the fluid flowing from each fluid flowing path of the cage 3 reaches the plug 7, the pressure of the fluid is equalized in the space where the protrusions 51 are formed, which serves to eliminate the force generated in the radius direction which is applied to the plug 7.

In the case where the fluid flows to the cage 3 from the lower portion of the plug 7, the protrusions 51 at the lowermost end of the cage 3 function as a back pressure device which can prevent the generation of excessive differential pressure on the leading end of the lower portion of the plug 7 which is contacted with the cage 3.

The above functions of the protrusions 51 can prevent the damage on the contact portion of the lower end of the plug 7 with the cage 3.

In the same manner as the labyrinth plug, the plug 7 can perform the up and down movements under the fluid flowing

conditions, and the plug 7 is in coaxial-contact with the seat 9.

The interval between the upper and lower portions of the circular holes 28 or the longitudinal holes 52 forms the fluid flowing path in the radius direction, in accordance with the position of the plug 7.

FIG. 5 is a sectional view illustrating the first internal cylinder 23 of the cage 3. The first internal cylinder 23 forms the concave/convex grooves 27 in the circumferential direction on the inside and outside surface thereof, for forming the rectangular section elbow 31, and forms the plurality of holes 28 by a predetermined interval on the concave/convex grooves 27.

Of course, the plurality of circular holes 28 may be replaced with the longitudinal holes 52 as shown in FIG. 4 or may be used together with the longitudinal holes 52.

A concave/convex portion, which is comprised of the concave/convex grooves 27 and the plurality of holes 28, forms the fluid flowing path in the radius and axial directions, in accordance with the position of the plug 7.

FIG. 6 is a sectional view illustrating the second internal cylinder 24 of the cage 3. The second internal cylinder 23 forms the plurality of holes 28 by a predetermined interval, in the same manner as the inside cylinder 25. Of course, the plurality of circular holes 28 may be replaced with the longitudinal holes 52 as shown in FIG. 4 or may be used together with the longitudinal holes 52.

FIGS. 7 to 9 show various fluid flows formed only with the concave/convex groove type cylinders, where the resistant portion is applied.

Firstly, one cylinder 71 as shown in FIG. 7 is same as the first internal cylinder 23 of FIG. 5 and the other cylinder 72 forms a hole 74 on a convex portion 73 thereof. And, a concave portion 75 of the cylinder 72 serves as an elbow with recess in the fluid flow.

The circular hole 74 may be replaced with the longitudinal hole 52 as shown in FIG. 4 or may be used together with the longitudinal holes 52.

FIG. 8 is a partial sectional view illustrating the cage 3 in

which only the cylinders with the concave/convex groove 27 are arranged. The one cylinder 81 forms a hole 83 on the lower portion of the concave/convex groove 27, and the other cylinder 82 forms a hole 84 on the upper portion thereof.

The circular holes 83 and 84 may be replaced with the longitudinal hole 52 as shown in FIG. 4 or may be used together with the longitudinal hole 52.

In this case, concave portions 85 and 86 of the cylinders 81 and 82 where the hole or groove is not formed serve as an elbow with recess in the fluid flow.

FIGS. 9A and 9B are partial sectional views illustrating the cage 3 in which a cylinder 91 with the concave/convex groove 92 are arranged on the one surface thereof. Holes 93 and 94 are crossedly formed within the concave/convex groove 92, and a concave portion 95 of the cylinder 91 where the holes 94 and 94 are not formed serves as an elbow with recess in the fluid flow.

FIG. 10 is a sectional view illustrating the assembling state of the inside cylinder 25 with the lower supporting plate 26 in the cage 3, as an integrated body with each other. Then, the outside cylinder 22 is formed as an integrated body with the upper supporting plate 21.

When the cage 3 operates with the plug 7, the protrusions 51, which provide a predetermined resistance as the back pressure control device for the fluid flow on the leading end of the lower portion of the plug 7, serve to the labyrinth part. Also, the protrusions 51 provide a round-shaped space between the plug 7 and the cage 3 to make the fluid flowing dispersion and the force applied to the plug 7 substantially uniform, to thereby prevent the interaction of the foreign materials with the plug 7.

The protrusion 51 may take a tapered shape having a predetermined angle or a rounded edge shape. If the protrusion 51 takes the tapered shape or the rounded edge shape, the contact area of the protrusion 51 with the plug 7 is small in the stable range of the structural interpretation, which allows the fluid flowing path to be smoothly switched in accordance with the movement of the plug 7 in

the axial direction.

On the other hand, the lower supporting plate 26 as integrated with the inside cylinder 25 may be formed as a unitary body with the seat 9, or may be formed separatedly with the seat 9.

FIG. 11 is a sectional view illustrating a valve in which flow for fluid is controlled according to a second embodiment of the present invention, in which disc type column is installed. A fluid flowing resistor 110, which is comprised of upper and lower discs 111 and 112, surrounds the plug 7 and is disposed on the seat 9.

The cage 3 as shown in FIG. 2 comprised of the cylinder is replaced with the fluid flowing resistor 110, as shown in FIG. 11, and the discs 111 and 112 of the fluid flowing resistor 110 are stacked in the axial direction to form the disc column.

A plurality of holes 113 and 114 angularly aligned with respect to the center of discs 111 and 112 penetrated through both sides of them are partially overlapped up and down, through which the fluid flows.

Protrusions 115 and 116 are formed on the inside and outside of the fluid flowing resistor 110 and serve to filter the foreign materials contained in the fluid to prevent the fluid flowing resistor 110 from being blocked. By the formation of protrusions 115 and 116 of the lower disc 112, the gap into which the fluid flow pass is equal or less to/than the minimal sectional distance of each fluid flowing path.

The protrusion 115 serves as the labyrinth part and performs the pressure dispersion of the fluid and the back pressure maintainment in accordance with the flowing direction of the fluid.

FIG. 12 is a partial plan view illustrating a pair of discs 111 and 112 of the disc type column of FIG. 11, in which the fluid flows through the plurality of holes 113 and 114.

The holes 113 shown by the solid line are formed on the upper disc 111, and the holes 114 shown by the dotted line are formed on the lower disc 112.

The holes 113 and 114 are formed in such a manner that a rectangular section elbow 117 is repeatedly formed in the radial

direction, and protrusions 124,124'and 125 125'are formed on the inside rectangular portion thereof to provide the orifice and elbow with recess functions.

The holes 113 and 114 of the discs 111 and 112 are formed in such a manner that each rectangular section elbow 117 has different inlet and outlet sectional areas.

The holes 113 and 114 may be formed in an electric spark machining, laser machining and so on.

The pair of discs 111 and 112 are stacked to form the fluid flowing path, and upper and lower supporting plates 118 and 119 are disposed on the both ends of the discs 111 and 112, to obtain the disc type column as the fluid flowing resistor 110.

The discs 111 and 112 are stacked in such a manner that they form a plurality of holes in an axial direction thereon and are fixed by means of a bolt or a pin through the holes or they are bonded in braze welding or laser welding.

The fluid flowing path may be formed at the arrow 120 from the disc inside to the disc outside of the arrow 121, or at the arrow 122 from the disc outside to the disc inside of the arrow 123.

Referring to the resistance operation to the fluid flowing path, velocity head loss is generated at the fluid inlet 120 on which the fluid flow is reduced, and is then generated as the fluid flow is bent through the rectangular section elbow 117 disposed in the opposite direction of the recess 126.

Thereafter, the velocity head loss is generated by a combined flow resistance on the orifice and elbow with recess 124, 124'and 125,125'of the rectangular section elbow 117 having different fluid flowing inlet and outlet sectional areas thereof.

Next, the fluid flow is bent twice through a rectangular section elbow 117a disposed between the upper and lower discs 111 and 112 and is dispersed as a labyrinth part, and is then bent twice through a rectangular section elbow 117'on the lower disc 112.

Thereafter, the fluid flow is bent twice through a rectangular section elbow 117a'and is dispersed as a labyrinth part. Every the steps as mentioned above, the velocity head loss is generated through the

fluid flow in the radius and axial directions from the upper disc 111 to the lower disc 112.

In other words, in case of the pair of discs 111 and 112, for example, each hole 113 and 114 forms into a module and the direction of the fluid flow in the module is changed eight times.

As set forth in the cylindrical cage 3 of the first embodiment of the present invention, the total loss coefficient increases by applying the orifice, the elbow with recess and the labyrinth part in a combined manner to the rectangular section elbow having the different inlet and outlet sectional areas, and the sectional area of the fluid flowing path is enlarged under predetermined pressure drop conditions. This provides various advantages in overall valve 5 structure.

Moreover, in the case where the fluid flowing paths 117a and 117a'of the upper and lower discs 111 and 112 are formed crossly with different widths in a circumferential direction, the sectional area of the fluid flowing path between the upper and lower discs 111 and 112 is reduced to thus achieve a high labyrinth effect, which results in the increment of the velocity head loss.

Such the arrangement is required to produce desired pressure drop and fluid velocity under specific flowing conditions.

FIG. 13 is a perspective view illustrating the pair of discs 111 and 112, in which the fluid flows from the outside of disc to the inside of disc. An inlet 130 and an outlet 131 for the fluid flowing path are formed only on the upper disc 111.

Of course, the inlet may be formed on the one disc 111 and the outlet on the other disc 112.

In addition, a protrusion 132 is formed on the lower disc 112 to prevent the fluid flowing path from being blocked by means of foreign materials and has a predetermined height in such a manner that the gap between lower discs 112 is lower than a minimum sectional length of the fluid flowing paths.

The interval between the protrusion 132 of the lower disc 112 and the groove 133 formed by the size of the upper disc 111 is formed to be equal or shorter to/than a minimum sectional length of

the fluid flowing paths of the upper and lower discs 111 and 112.

If the fluid flows from the disc inside to the disc outside, the formation of the protrusion 132 and the groove 133 on the disc outside is not needed.

A protrusion 134 on the lower disc 112 forms an edge as shown in FIG. 15A and 15B for reducing the contact area with the plug 7, to smoothly open/close the fluid flowing path in accordance with the movement of the plug 7, and it disperses the fluid flow, to remove the force in the radius direction applied to the plug 7.

Furthermore, the protrusion 134 is in contact with the plug 7, thus serving as the labyrinth part, whereby the fluid can flow in linear and smooth manner in accordance with the movement of the plug 7.

In this case, if the fluid flows from the disc inside to the disc outside, the protrusion 134 forms a round-shaped space in the vicinity of the plug 7, to thereby supply the back pressure to the leading end of the plug 7 and prevent the interaction of the plug 7 with the foreign materials.

FIG. 14A shows a single disc 135 having a groove 136, angularly aligned with respect to the center of discs, where rectangular section elbows each having the orifice and the recess as shown in FIG. 12 are repeatedly arranged in the radius direction, and forming a protrusion 137 on inner and outer side of disc 135.

The shape, size and number of the resistor is appropriately adjusted and determined in accordance with the velocity of fluid and the pressure drop.

FIG. 14B shows the discs 135 as stacked, in which the fluid flowing direction is illustrated.

The fluid can flow the disc outside to the disc inside, or reversely.

FIG. 15A shows various flowing patterns and the labyrinth function in the state where the fluid passes through the fluid flowing inlet 130 and outlet 131 of the discs, when the upper disc 111 and the lower disc 112 which are machined in an appropriate depth are stacked in turn.

In more detail, the fluid flowing pattern to the fluid flowing inlet

130 and the fluid flowing outlet 131 of the disc is formed from the upper disc 111 to the upper disc 112, from the upper disc 111 to the lower disc 111, the lower disc 112 to the upper disc 111, and the lower disc 112 to the lower disc 112, in accordance with the conditions of the fluid and the operating conditions of the valve 5.

The protrusion 115 in contact with the plug 7 is formed by a rounded edge or a beveling as shown in FIG. 15A and 15B, which prevents the fluid increment/decrement of the upper and lower discs 111 and 112 from being intermittent in accordance with the up and down movement of the plug 7, to smoothly control the fluid flow.

Additionally, the narrow contact portion with the circumferential space thereof serves as the labyrinth part.

FIGS. 16A to 16D are partial sectional views illustrating the function separation plug 7, the seat 9, and the supporting plate 26 or 118, in which the plug 7, which takes a rod shape, is made by cutting the bottom portion thereof to have a cylindrical shape.

For the function separation of the plug 7, the plug 7 is comprised of a sealing portion 102 which is in contact with the seat 9 and an opening/closing portion of the fluid flowing path of the fluid flowing resistor 4.

The sealing portion 102 has an edge with a predetermined angle or is rounded to be in a close contact with the seat 9.

The fluid flowing path opening/closing portion 103 forms a groove 104 on the upper surface thereof, through which a plurality of holes 105 for bypassing the fluid flowing path opening/closing portion 103 are formed to thereby perform the fluid flow dispersion to the fluid flowing path opening/closing portion 103.

The circular holes 105 may be replaced with the longitudinal holes 52 as shown in FIG. 4.

The interval between the sealing portion 102 of the plug 7 to the seat 9 and the fluid flowing path opening/closing portion 103 may be long, but it depends upon the distance thereof from the fluid flowing path of the fluid flowing resistor 4.

The plug 7 moves to the lower portion thereof from the inside of the fluid flowing resistor 4, and when the fluid flowing path

opening/closing portion 103 is disposed in the vicinity of the fluid flowing path closing position, as shown in FIG. 16B, the fluid flows to the groove 104 on the upper portion of the fluid flowing path opening/closing portion 103 and the holes 105, to thereby disperse the pressure operated on the fluid flowing path opening/closing portion 103. As a result, as the velocity of the fluid is not high, no cavitation or damage is generated on the contact portion of the fluid flowing resistor 4 with the plug 7 and on the fluid flowing path opening/closing portion 103.

Thereafter, the plug 7 moves further to the lower portion thereof, and before it is in contact with the sealing portion 102 of the seat 9, the fluid flowing path opening/closing portion 103 closes the fluid flowing path of the fluid flowing resistor 4, as shown in FIG.

16C. Then, the plug 7 is in close contact with the sealing portion 102 of the seat 9, as shown in FIG. 16D, to completely close the fluid flow. To the contrary, if the plug 7 moves to the upper portion thereof in the state where the plug 7 has been in close contact with the seat 9, the sealing portion 102 of the seat 9 is firstly opened and the fluid flowing path of the fluid flowing resistor 4 is then opened.

As a result, when the fluid flows between the lower portion of the plug 7 and the seat 9, the velocity of fluid flow is not high on the sealing portion 102, to thereby prevent the damage of the sealing portion 102 of the plug 7 and the sealing portion 102 of the seat 9.

In this case, the seat 9 and the supporting plate 26 or 118 may be integrated with each other in consideration of the valve and fluid conditions.

FIG. 17A is a partial sectional view illustrating a circumferential protrusion 106 between the fluid flowing path opening/closing portion 103 and the sealing portion 102 of the plug 7. The plug 7 can be inserted on the upper portion of the sealing portion 102 of the seat 9, and the plug 7 forms a circumferential protrusion 107 corresponding to the protrusion 106 of the plug 7. Thus, before the sealing portion 102 of the seat 9 is in contact with the sealing portion 102 of the seat 9, a rectangular section elbow is formed to supply a predetermined resistance to the fluid flow, thus preventing

the damage of the fluid flowing path opening/closing portion 103 of the plug 7.

In other words, the mechanical damage and the fluid flow, which can be generated due to errors such as the manufacturing tolerance of the groove 104, the holes 105, the fluid flowing path opening/closing portion 103, and the contacted parts with the plug 7, can be effectively prevented and adjusted. However, under more stable conditions, with only the rectangular protrusion, the mechanical damage can be prevented and the fluid flow can be desirably controlled.

The protrusions 106 and 107 include of course additional protrusions in accordance with the fluid conditions, to thereby generate multi-step pressure loss.

FIG. 17B is a partial sectional view illustrating a groove 109 formed on the protrusion 106 of the upper portion of the sealing portion 102 of plug 7 and the groove 108 formed on the protrusion 107 on the upper portion of the sealing portion 102 of the seat 9, to supply the predetermined resistance to the fluid flow through the multi-step rectangular section elbow. A plurality of protrusions having <BR> <BR> groove can be formed as shown on Fig. 18. At this time, the height of the circumferential protrusion 107 on the uppermost portion of the sealing portion 102 should be higher than the height of the other lower side protrusions. As a result, the sealing portion 102 of the seat 9 along the movement of plug is firstly separated from the plug 7, to thereby prevent the damage of the sealing portion 102 and perform a smooth fluid flow control.

FIG. 18 is a partial sectional view illustrating a fluid flow control device of a valve according to a third embodiment of the present invention, where a fluid flowing resistor 40 and a seat 41 are integrated with each other, which takes a cylindrical shape and forms a plurality of holes 42 as fluid flowing paths, a protruded groove 43 and a protrusion 44. The plug 7 forms a groove 48 and a protrusion 46 which are inserted to correspond with the protruded groove 43 and the protrusion 44, with clearance 45 in the circumferential direction.

Of course, the seat 41 as integrated with the fluid flowing resistor 40 may be replaced with the cylindrical or disc shape of resistor 4, or it may be separately installed from the resistor 40. The shape of the fluid flowing path, that is, the hole 42 may be changed into the longitudinal hole 52, an inverted triangle and the like.

Under the above construction, if the two parts are in contacted with each other, the sealing portions thereof are sealed. In this case, if the plug 7 moves in the axial direction of the fluid flowing resistor 40, the grooves 43 and 48 and the protrusions 44 and 46 of the two parts form the fluid flowing path of the rectangular section elbow to thereby supply the velocity head loss for the fluid flow. As a result, the velocity of fluid flow is not accelerated and an amount of fluid flow can be increased, while having a constant velocity variation.

Particularly, the device of the third embodiment of the present invention can preserve the sealing portion thereof from the fluid flow, such that an additional seat is not needed. Moreover, in the state where the fluid flowing path is slightly opened, the number of resistant portions for the fluid is increased by steps. Also, as shown in a broken line, in the state where the two parts are considerably opened, the resistance operation of the rectangular section elbow is changed in the circumferential and axial directions to thereby perform more precise fluid flowing control.

The methods applied to the fluid flow control device of the present invention can be applied to a pressure reducing device and a back pressure reducing device, in the same manner as above.

Therefore, the fluid flow control device of the present invention can be used in all parts of the fluid control device for increasing/decreasing or adjusting a predetermined amount of fluid flow.

Furthermore, the function separation type plug may be applied in all fluid flowing control device performing a fluid flowing closing operation, to thereby prevent the damage of the related parts to the plug.

Industrial Applicability

As apparent from the foregoing, a fluid flowing control device of a valve of the present invention can control valve operation, fluid resistance back pressure and overall operations in connection with a mechanical technology used in the treatment for various kinds of fluids such as, for example, compressive fluid, non-compressive fluid and the like, and control the velocity of fluid by the maximal use of available volume thereof, to thereby prevent to a maximal extent the generation of cavitation, flashing, blocking by foreign materials, and the damage of internal parts thereof. Moreover, a fluid flowing control device of a valve according to the present invention can generate a large amount of velocity head loss every resistor on a plurality of fluid flowing paths to increase a sectional area per the fluid flowing path on the constant differential pressure conditions applied to the valve, whereby the fluid flowing path is not blocked by the foreign materials passing through the valve to thereby increase an amount of the fluid flow within a predetermined volume thereof.