AU2010223831B2

AU2010223831B2 - Control valve element

Info

Publication number: AU2010223831B2
Application number: AU2010223831A
Authority: AU
Inventors: Hannes Schuster-Ofner-Abschlag
Original assignee: HERZ ARMATUREN GmbH
Current assignee: Herz Armaturen Gesmbh
Priority date: 2009-03-09
Filing date: 2010-03-08
Publication date: 2014-11-27
Anticipated expiration: 2030-03-08
Also published as: AU2010223831A1; EP2406528A1; KR101709524B1; HRP20130064T1; AT507907B1; UA101738C2; PL2406528T3; KR20110137355A; AT507907A4; EP2406528B1; WO2010102317A1; RU2495307C2; SI2406528T1; RU2011140819A

Abstract

The invention relates to a control valve element, comprising a valve housing (1), through which a displaceable adjusting element (2) extends, which carries a cylindrical piston-shaped control element (3) at the end thereof that is removed from the valve housing (1). According to the invention, the control element (3) comprises at least one central passage (4), a central chamber (5) into which one end of the central passage (4) leads is designed between the valve housing (1) and the control element (3), the central chamber (5) is delimited by an inner partial region of the back surface of the control element (3) located opposite of the face, the central passage (4) has a central mouth (47) at the face (31) of the control element (3), a peripheral chamber (8) that is sealed with respect to the central chamber (5) is designed between the valve housing (1) and the back surface of the control element (3), the control element (3) has a spaced peripheral passage (7) which at one end opens into the peripheral chamber (8) and at the other end thereof opens into the face (31), and the mouth (77) of the peripheral passage (7) is spaced from the mouth (47) of the central passage (4) at a predetermined radial distance (A).

Description

Translation from German of PCT Application PCT/A T2010/000069 Control valve element 5 The invention concerns a balanced control valve element according to the preamble of claim 1. Control valve elements of this kind are used for 10 controlling flow or differential pressure respectively in control valves, in particular in heating and cooling systems in buildings. Particularly with membrane-controlled valves the problem 15 often occurs where the control element is subjected to varying forces that result from the water flowing through, depending on the water flow rate. If the water flows through the valve seat of the valve to be controlled at a slow velocity but at high pressure, the 20 control element is displaced as a result of the high pressure, for example against the force of a spring. At a small flow rate of the water the control element is displaced to a lesser degree since the water pressure and the force of the spring are in balance in a different 25 position. Such a behaviour of a valve control element poses a problem, however, if adjusting forces in addition to the force of the spring, for example one applied by a membrane, are acting on the control element or on an adjusting element respectively to which it is connected. 30 In this instance the position of the control element is dependent on the water flow rate at any given time. This leads to a behaviour of the control element in which its position is not only dependent on the adjusting force at 2 the time but also on the current water flow rate through the valve seat. An additional dependence of this kind poses a problem in that the control response becomes undefined, or an additional disturbing force variable 5 respectively acts on the control element. It is thus the object of the invention to provide a control valve element whose control element exhibits an adjusting characteristic in which the position of the 10 control element remains largely independent of the water flow rate through the valve seat. Moreover, the physical size is to be limited and the design simple. A further problem was recognised in this regard in that 15 the pressure of the water flowing through the valve seat is not constant but decreases due to the narrowing of the flow cross-section from the centre of the valve seat, or the sealing area of the control element respectively, towards its outer section. For this reason the commonly 20 used methods for relieving the pressure from a valve control element cannot be applied in this instance since different pressure conditions occur in the centre and in the outer region of the face of the control element, depending on the velocity of the water as well as the 25 position of the control element. It is the object of the invention to solve the problems described earlier, and to provide a pressure-balanced control valve element that exhibits the same control 30 response independent from water pressure, or water flow rate respectively, as well as from its position. The position of the control element is only determined by the adjusting variable, whilst neither the position of the 3 control element nor the water flow rate have an influence on the control element. The object of the invention is met with a control valve 5 element according to the preamble of claim 1 with the characteristics of the attribute of claim 1. Preferred embodiments of the control valve element are described in the dependent sub-claims. 10 The advantage according to the invention lies in the fact that, due to the pressure drop at two radially distant outlets of separate passages the different pressure conditions between central and outer regions of the face 15 of the control element are tapped separately and are guided into separate chambers that are sealed from each other and which have no direct fluid connection. A preferred embodiment according to claim 2 provides the 20 advantage that the positioning of the peripheral passage, or its outlet respectively, can be simply set in the flow region located in front of the face of the control element. By using different end plates it is possible to set different outlet positions of the peripheral passage. 25 If there are multiple peripheral passages, they have the same distance from the axis of the cylindrical control member. The peripheral passage has the outlet advantageously at the edge or the circumference respectively of the circular end plate. 30 A particularly simple design can be achieved with the characteristics of the attribute of claim 3.

4 A simple differential pressure controller is provided with the attribute of claim 4, where the differential pressure is the difference between the pressure applied to the central passage and a predetermined pressure on 5 the membrane. An embodiment of the valve element according to the invention that is particularly easy to manufacture and works very accurately is distinguished by the 10 characteristics of the attribute of claim 5. A simple design of a preferred embodiment according to claim 6 provides for the simple presetting of an externally tapped pressure used for valve control. 15 A valve element with the characteristics of the attribute of claim 7 provides for a particularly simple design of the peripheral passage. The radial distance is selected depending on the expected actuating parameters of the 20 water flow and the desired control characteristic. A valve element with the characteristics of the attribute of claim 8 not only provides an accurate and consistent control characteristic but also a space-saving design. 25 In a valve element according to the characteristic of the attribute of claim 9 the position of the outlet, or outlets respectively, of the peripheral passage can be set accurately for many fields of application. 30 With the characteristics of the attribute of claim 10 the equalisation pressure, or the resulting equalisation force respectively, from the peripheral chamber can be 5 accurately set. Moreover, a smaller membrane can be chosen than those used in current membrane control valve designs. 5 Preferred embodiments of a valve element or a valve arrangement respectively according to the invention are described in more detail by way of the drawing. Fig. 1 depicts an embodiment of a control valve 10 element according to the invention; Fig. 2 depicts a valve device with control valve element installed in open position; Fig. 3 depicts the end plate of the control valve element; 15 Fig. 4 depicts the control element of the control valve element. Fig. 1 shows a preferred design according to the invention of a control valve element 10 in cross-section. 20 Control valve element 10 comprises a valve housing 1, in which adjusting element 2 is moveably supported. The adjusting element 2 is cylindrical and extends through a cylindrical bore 11 of valve housing 1. The radius of the cylindrical bore 11 is approximately 1% to 5% greater 25 than the radius of the adjusting element so that the adjusting element 2 is able to move without friction in relation to valve housing 1. During operation of the control valve element 10 the intermediate region between adjusting element 2 and valve housing 1 is additionally 30 filled with water, where said intermediate region acts as pressure line.

6 Disposed at the end of adjusting element 2 which is furthest from valve housing 1 is a piston-shaped or cylindrical control element 3, which is shown in detail in Fig. 5 [sic]. Said control element 3 comprises a 5 sealing surface or face 31 respectively, which faces away from valve housing 1. In this particular embodiment the axis X of the cylindrical control element 3 is identical to the axis X of the cylindrical adjusting element 2. 10 The control element 3 provides a continuous central passage 4, which extends axially to valve housing 1 from face 31 of control element 3 to its back surface 35, which is located opposite face 31. Adjusting element 2 passes through said central passage 4 preferably only in 15 part so that on the one hand movements of adjusting element 2 are transferred directly to control element 3, and on the other hand that the water pressure, which is present at the outlet 47 of central passage 4 at face 31, can act without restriction in the region of the entire 20 central passage. This means that a sufficiently large cross-section, for example in the vicinity of a few square millimetres, is available for the pressure transfer, with which the pressure at outlet 47 of central passage 4 at face 31 can be passed on through central 25 passage 4. In the embodiment of control valve element 10, depicted in Fig. 1, the valve housing 1 comprises two hollow cylinder-shaped or respectively annular cylinder-shaped 30 annular protrusions 14, 15 that have approximately the same thickness. The radius of the inner annular protrusion 14 is naturally smaller than the radius of the outer annular protrusion 15. Moreover, the back surface 7 of control element 3 provides two hollow cylinder-shaped or respectively annular cylinder-shaped annular protrusions 32, 33 with different radius, that is, an inner annular protrusion 32 of control element 3 as well 5 as an outer annular protrusion 33 of control element 3. The outer generated surface areas of the inner and outer annular protrusion 14, 15 respectively of valve housing 1 as well as the inner generated surface areas of the inner and outer annular protrusion 32, 33 respectively of 10 control element 3 do not necessarily have to have a cylindrical shape but may have a slightly conical shape as shown, for example, in the outer region of the inner annular protrusion 14 of valve housing 1. 15 The internal radius of the inner annular protrusion 14 of housing 1 essentially corresponds with external radius 32 of the inner annular protrusion of control element 3, in which the external radius of the inner annular protrusion 32 of control element 3 is smaller by approximately 0.15 20 mm to 0.2 mm than the internal radius of the inner annular protrusion of housing 1. The dimensions of the outer annular protrusions 15, 33 relate to each other in the same way: The internal radius 25 of the outer annular protrusion 15 of housing 1 essentially corresponds with external radius of the outer annular protrusion 33 of control element 3, in which the external radius of the outer annular protrusion 33 of control element 3 is smaller by approximately 0.15 mm to 30 0.2 mm than the internal radius of the outer annular protrusion 15 of housing 1.

8 The inner annular protrusion 14 of valve housing 1 thus surrounds the inner annular protrusion 32 of control element 3. The outer annular protrusion 15 of valve housing 1 thus surrounds the outer annular protrusion 33 5 of control element 3. The inner and outer annular protrusion 14, 15 of valve housing 1 in this embodiment comprise in their external generated surface area annular grooves 16, 17 that are fitted with sealing rings 18, 19. If during a movement of adjusting element 2 the control 10 element 3 is displaced or actuated compared to valve housing 2 [sic], sealing rings 18, 19 slide along the inner circumference region of the inner and outer annular protrusion 14, 15 respectively. The volume of the two from each other separated chambers 5, 8, that is, the 15 central chamber 5 in the inner region of the inner annular protrusion 14 of valve housing 1 and a peripheral chamber 8 in the region between the inner annular protrusion 14 of valve housing 1 and the outer annular protrusion 15 of valve housing 1, is changed 20 correspondingly. The central chamber 5 is delimited by valve housing 1 as well as the inner annular protrusion 32 of control element 3. The central passage 4 ends inside chamber 5. 25 In this embodiment the valve housing 1 features a recess 51 on the side facing control element 3 in the inner region of the inner annular protrusion 32, which surrounds the discharge region of the centrally and axially positioned adjusting element 2. Said recess 51 30 extends to approximately half of the surface of the valve housing 1 inside the inner annular protrusion 14. Outside it and inside the inner annular protrusion 14 the surface of valve housing 1 extends approximately parallel to face 9 31 of control element 3 or perpendicular to axis X of adjusting element 2 respectively. Said recess 51 is part of the central chamber 5. 5 The peripheral chamber 8 is formed between the inner and the outer annular protrusion 14, 15 of valve housing 1 and is delimited by control element 3. Peripheral chamber 8 features a peripheral passage 7, which leads from the peripheral chamber 8 to face 31 of control element 3 and 10 opens out at a distance A from axis X of control element 3. If the adjusting element 2 is displaced compared to valve housing 1, with the result that the control element 3 is 15 moved out of valve housing 1, the central chamber 5 and the peripheral chamber 8 become larger. The pressure present at the outlet 47 of central passage 4 is transferred into the inside of central chamber 5 20 and, due to the approximately static pressure conditions, it is present particularly at each point of the wall surface of central chamber 5. The force acting on control element 3 is dependent on the pressure as well as on the pressure-effective surfaces. In the present exemplary 25 embodiment the pressure-effective surface of central chamber 5 equals the projection of the surface of the inner annular protrusion 32 of control element 3 that faces valve housing 1 onto face 31 of control element 3. If the surface of the inner annular protrusion of control 30 element 3, which faces valve housing 1, and the face 31 of control element 3 are parallel, the pressure-effective surface is equal to that of the surface of the inner 10 annular protrusion 32 of control element 3 that faces valve housing 1. In the same way we derive the force that is applied by 5 the pressure in peripheral chamber 8 onto control element 8, where the pressure inside the peripheral chamber 8 equals the pressure present at the outlet 77 of peripheral passage 7 at face 31 of control element 3. The pressure-effective area corresponds approximately to the 10 area of a circular ring with an inside diameter that is equal to the outside diameter of the inner ring protrusion 14 of valve housing 1, and an outer diameter that is equal to the inner diameter of the outer ring protrusion 33 of control element 3. 15 Fig. 1 shows, furthermore, an end plate 12 subsequent to control element 3; a three-dimensional view of end plate 12 is shown in Fig. 3. As is apparent from Fig. 1 and 4, control element 3 has a number of continuous, cylindrical 20 channels 71 that extend from the face 31 to the back surface 35 of control element 3. The cylindrical channels 71 are advantageously arranged in equal distance from the X axis of control element 3 as well as in equal azimuthal distance from each other, extending parallel to the X 25 axis. Fig. 1 shows said channels 71 in cross-section. In the present exemplary embodiment part of the peripheral passage 7 from peripheral chamber 8 to face 31 of control element 3 are formed by the cylindrical channels 71 of control element 3. End plate 12, which is located 30 subsequent to control element 3, features on the side that is oriented towards the face 31 of control element 3 a circular recess 72, where the centre of the circle is located on the X axis of the cylindrical control element 11 3 and where the radius of the circle equals the distance of recess 71 from the X axis of the cylindrical control element 3. The width of said recess 72 corresponds approximately to the diameter of recess 71; the width of 5 recess 72 could be made larger if required. Endplate 12 features, furthermore, a number of radially outwards directed recesses 73 that connect to circular recess 72 and extend to the circumference of end plate 12. The depth and width of recess 72 and the further recesses 73 10 may be in the range of a few 100 pim. End plate 12 is immediately adjacent to the face of control element 3. The diameter of recesses 71, the width of recess 72 as well as the width of the further recesses 73 is in the range between 500 pm and 2 mm. The cross-section of 15 recesses 71, the width of recess 72 as well as the width of the further recesses 73 is in the range between 0.2 mm 2 and 2 mm Moreover, end plate 12 features a passage 41 that 20 continues from the central passage 4, where said continuing passage 41 opens out, on the side of the end plate 12 that faces away from face 31, in the vicinity of the X axis of the control element 3. The continuing passage 41 is sealed towards the annular recess 72, where 25 control element 3 features at its face 31 an annular groove 69 into which a sealing ring 68 is fitted. The position or the radius respectively of sealing ring 68 or annular groove 69 respectively is chosen such that one of the outlets 47 of the central passage 4, but not the 30 outlets 77 of recess 71 located at the face, is enclosed by sealing ring 68.

12 The following explains the term 'pressure-effective surface' in more detail. Surfaces of valve components that are subjected to water pressure are not necessarily oriented perpendicular to the direction of their surface 5 but are often at an angle or tilted with respect to the closing direction of the valve. Thus to determine the effective forces, that is, the forces in the direction of the X axis or in closing direction respectively, an effective area is determined through projecting the 10 respective area, for example the membrane area, onto an area that is perpendicular to the X axis or to the closing direction respectively. The projection of an area that is partially curved is called the effective or pressure-effective area, or the pressure-effective 15 portion of an area respectively. This makes a simple calculation of the force distribution possible, just on the basis of the pressure acting on the pressure effective areas. The pressure-effective area of a membrane is, for example, simply called pressure 20 effective membrane area. The following dimensions have proven to be advantageous in the current instance: The pressure-effective area of end plate 12 is between 60% and 80% of the pressure 25 effective face area 31 of control element 3. Since face 31 of control element 3 is in the current instance oriented perpendicular to the X axis, the area of face 31 and the pressure-effective area of face 31 are equal. 30 The peripheral passage 4 is formed by the recesses 71, the annular recess 72 of end plate 12 as well as the radial further recesses 73 of end plate 12.

13 In the control valve element 10 depicted in Fig. 1 the water pressure is distributed via the central passage 4, that is, the intermediate region between the adjusting element 2 and valve housing 1, from the end plate 12 to 5 the central chamber 5. Moreover, from the end of central chamber 5 that is furthest away from control element 3 a continuation of the central passage 4 leads to a first control chamber 101 in the intermediate region between adjusting element 2 and valve housing 1. Said control 10 chamber 101 is delimited on the one hand by valve housing 1 and on the other hand by membrane 110. As depicted in the present exemplary embodiment, said membrane 110 is connected with adjusting element 2, where a deflection of membrane 110 causes an adjusting movement of adjusting 15 element 2 and thus also of control element 3. On the other side of membrane 110 a second control chamber 102 extends, which features a pressure control connection 105 for a preset pressure or counter-pressure respectively on the membrane 110. 20 Due to the favourable flow characteristics of the control valve element 10 according to the invention the area of membrane 110 can be very small so that the pressure effective area of face 31 of control element 3 is in the 25 range between 25% and 50% of the pressure-effective membrane area 110. A valve device 500, as depicted in Fig. 2, can be provided in a simple manner by way of control valve 30 element 10 shown in Fig. 1. The valve device 500 shown comprises an inlet 501 and a discharge 502, in which a valve seat 503 is provided whose area is oriented parallel to the flow direction. Water flows first through 14 inlet 501, passes valve seat 503, and the control element 3 is disposed in the downstream region of valve seat 503. Control valve element 10 passes through an opening 507 of the generated surface area, which is located downstream 5 of valve seat 503, of housing 510 of valve arrangement 500. Opening 507 has an external thread 508, and control valve element 10 is inserted into opening 507. The control valve element 10 is retained with its housing 1 between a union nut 520 with internal thread and the edge 10 of opening 507. The union nut 520 screws onto external thread 508 and thus determines the position of control valve element 10 with respect to the valve device 500. Control element 3 of control valve element 10 closes 15 valve seat 503, or regulates the flow through valve seat 503 against the pressure of the water respectively. During its regulating movements control element 3 is thus subject to continuous pressure variations of the water pressure, and in addition there is a spatially 20 inhomogeneous pressure applied to the face 31 of control element 3. The pressure in the region of the X axis is significantly greater than in the peripheries or the regions of face 31 that are closer to the outer edge. 25 The regulating process is caused on the one hand by the forces acting on membrane 110, which are the result of the reference pressure applied to pressure control connection 105 as well as the water pressure present in the central water passage 4. Membrane 110 is held in a 30 preset equilibrium by means of spring 107 and thus also assumes a preset position. Said equilibrium position is dependent on the water flow rate. If the water flow rate increases, a greater radial pressure drop across the face 15 of control element 3 is present, which displaces the set equilibrium position and reduces the flow. However, as provided according to the invention, if 5 pressure is applied in the peripheral region of face 31 in chamber 8 to control element 3, the reduced force caused by the water flow is largely compensated for by a reduced opposing force from the peripheral chamber 8, which reduces the dependence of the equilibrium position 10 on the water flow rate. Thus the equilibrium position is dependent only on the pressure differential applied to membrane 110, but not on the flow conditions at valve seat 503 or the face 31 respectively. 15 Because the relationship between the water pressure drop behaviour and the flow rate is not linear, peripheral chamber 8 can be optimally designed for required water flow rates. The portion of the area of the effective internal surface of peripheral chamber 8, which is 20 oriented towards face 31 of control element 3, is advantageously between 85% and 115% of valve seat 503.

Claims

1. Control valve element comprising a valve housing (1), through which a displaceable adjusting element (2) passes, which carries a cylindrical, piston 5 shaped control element (3) at the end that is furthermost from the valve housing (1) and with which a valve seat can be closed, in which - control element (3) provides at least one central passage (4), which extends in particular within the region of the axis (X) of control element (3) and which is at least partially penetrated by adjusting 10 element (2), - a central chamber (5), which directly surrounds adjusting element (2), is formed between valve housing (1) and control element (3), and into which one end of the central passage (4) opens out, - the central chamber (5) is delimited by a partial section of the back 15 surface of control element (3), which is located internally, or is close to the central passage (4) respectively, and which is located opposite the face, - a peripheral chamber (8) is formed between valve housing (1) and the back surface of control element (3), which is sealed towards or 20 separated respectively from central chamber (5) and which may surround central chamber (5), and - control element (3) has at least one peripheral passage (7) located at a distance from central passage (4), where one end of said peripheral passage (7) opens out into peripheral chamber (8) and the other end 25 opens out to face (31) of control element (3), which is exposed to the flow, characterised in that - the central passage (4) features a centrally located outlet (47) on that face (31) of control element (3) that is exposed to the flow of the fluid that flows through the valve seat and is to be controlled, said centrally 30 located outlet (47 being located in particular in the vicinity of axis (X), - that the outlet (77) of peripheral passage (7) and the outlet (47) of central passage (4) are disposed inside the edge region of the face (31) 17 exposed to the flow, which edge region is in sealing contact with the valve seat, and - that the outlet (77) of peripheral passage (7) is located at a distance from outlet (47) of central passage (4) on face (31) that is exposed to 5 the flow at a predetermined radial distance (A).

2. Control valve element according to claim 1, characterised in that located in front of the face of control element (3) is end plate (12), which is supported by adjusting element (2) and/or by control element (3), and that part of the 10 peripheral passage (7) is formed by a channel, which in turn is formed in particular by recesses (72, 73) in end plate (12) that are located between control element (3) and end plate (12).

3. Control valve element according to any one of the previous claims, characterised 15 in that valve housing (1), adjusting element (2), control element (3) and/or both chambers (5, 8) are rotationally symmetric.

4. Control valve element according to any one of the previous claims, characterised in that 20 - adjusting element (2) is actuated by, or connected to respectively, a membrane (110), preferably in the region that faces away from control element (3), where the surface of said membrane together with valve housing (1) delimits a first control chamber (101), and - that the central passage (4) leads to the first control chamber (101). 25

5. Control valve element according to claim 4, characterised in that adjusting element (2) passes through that part of the central passage (4) between the central chamber (5) and the first control chamber (101). 30

6. Control valve element according to claim 4 or 5, characterised by a second control chamber (102), which is delimited by valve housing (1) and the other 18 surface membrane (110) and is provided with an external pressure control connection (105).

7. Control valve element according to any one of the previous claims, characterised 5 in that the peripheral passage (7) of control element (3) is provided with a number of channels (71) that extend in control element (3) and which lead through the body of control element (3) from the peripheral chamber (8) into a recess (72, 73) that is formed by end plate (12) and/or is located between end plate (12) and control element (3) and which open out into outlet (77) at a preset 10 distance (A) from outlet (47) of central passage (4) in the edge region of end plate (12).

8. Control valve element according to any one of claims 4 to 7, characterised in that the pressure-effective area of face (31) of control element (3) is in the range 15 between 25% and 50% of the pressure-effective area of membrane (110).

9. Control valve element according to any one of claims 2 to 8, characterised in that the pressure-effective area covered by end plate (12) is between 60% and 80% of the pressure-effective area of face (31) of control element (3). 20

10. Control valve element according to any one of the previous claims, characterised in that the pressure-effective portion of the inner surface of peripheral chamber (8), which is oriented towards the face (31) of control element (3), is between 85% and 115% of the pressure-effective area of face (31) of control element (3). 25

11. Valve device comprising an inlet (501), an outlet (502) and a valve seat (503), which is disposed in between, characterised by a control valve element (10) according to any one of the previous claims, in which the control element (10) is disposed opposite the valve seat and closes the valve seat (503), or adjusts the 30 distance of the flow cross-section between control element (3) and valve seat (503).