A valve with a flow control arrangement and a differential pressure regulator

Abstract

A valve (1) comprises a valve housing (2) with a flow control arrangement (6); and a differential pressure regulator (7) for maintaining a constant differential pressure across the flow control arrangement (6), wherein the differential pressure regulator (7) comprises a cup-shaped, valve member (8) positioned in a valve chamber (13) in the valve housing (2), the valve member (8) comprising a rim (9), wherein the valve chamber (13) comprises a space (17) around the valve member (8) said space (17) comprising an annular area (18) radially outside the rim (9), wherein an inlet passage (19) from a valve inlet (4)10 of the valve to the flow control arrangement (6) comprises a smallest inlet cross-sectional area (20), and a ratio between the size of the annular area (18) and the size of the smallest inlet cross-sectional area (20) is at least 2.4.

Description

[0001] A valve with a flow control arrangement and a differential pressure regulator

[0002] The present disclosure relates to a valve comprising a valve housing with an axis defining an axial direction through the housing; a valve inlet; and a valve outlet. The valve further comprises a flow control arrangement adapted for dynamic control of a flow of liquid through the valve; and a differential pressure regulator for maintaining a substantially constant differential pressure across the flow control arrangement.

[0003] Thus, the flow control arrangement is adapted for dynamic adjustment of the flow through the valve.

[0004] The differential pressure regulator comprises a cup-shaped, first valve member positioned in a valve chamber in the valve housing, the first valve member comprising a rim circumscribing a first area and being movable in the axial direction towards a first valve seat in the valve chamber for the rim of the first valve member to cooperate with the first valve seat, the first valve member comprising a first side proximal to the first valve seat and an opposite, second side distal from the first valve seat.

[0005] The first valve member is in a manner known per se adapted to set itself in a balance between i.a. an upstream pressure (P1 ) on the second side of the first valve member equal to a pressure at an inlet to the flow control arrangement and a downstream pressure (P2) on the first side of the first valve member equal to a pressure at an outlet from the flow control arrangement together with a spring force.

[0006] The valve chamber comprises a space around the first valve member said space comprising an annular area perpendicular to the axis, said annular area being positioned at the first valve seat radially outside the rim of the first valve member and the first area. An inlet passage from the valve inlet to the flow control arrangement comprises a smallest inlet cross-sectional area.

[0007] The valve may e.g. be used in a heating or cooling system, e.g. for controlling a flow of liquid, such as water, into a heating or cooling device.

[0008] Valves of the above art are known in a number of embodiments and examples are e.g. disclosed in W02009135490A2, WO2014044282A2, EP3708884A1 , and EP4151893A1. The well known function of this kind of valves is that for a range of liquid pressure at the valve inlet, the differential pressure regulator will maintain a constant pressure across the flow control arrangement and accordingly, without adjusting the flow control arrangement the flow through the valve is maintained substantially constant even though the pressure at the valve inlet and / or the pressure at the valve outlet, i.e. the pressure difference between the valve inlet and the valve outlet varies within a certain range.

[0009] While in the ideal case a valve as defined by way of introduction should keep the flow through the valve absolute constant regardless variations of the pressure difference across the valve from the valve inlet to the valve outlet, some embodiments of real valves tend to provide a slightly varying flow when the pressure difference across the valve varies and the variation of the flow may even be different when the pressure difference across the valve is increasing relative to the variation when the pressure difference across the valve is decreasing.

[0010] During continued development the present inventors have discovered that a valve’s ability to maintain a constant flow, while the pressure difference between the valve inlet and the valve outlet varies, depends i.a. on a ratio between the size of the above-mentioned annular area and the size of the likewise above-mentioned smallest inlet cross-sectional area.

[0011] It is an object of the present invention to minimize variations of a flow through a valve of the kind mentioned by way of introduction when the pressure difference across the valve varies.

[0012] This is obtained according to the present disclosure when the ratio between the size of the annular area and the size of the smallest inlet cross-sectional area is at least 2.4.

[0013] Regarding the annular area and the size thereof it should be understood that the annular area is found within the outline of a circumferential wall of the valve chamber at an axial position of the first valve seat, disregarding the valve outlet that may extend from the valve chamber at that axial position.

[0014] The circumferential wall may be coaxial with the first valve seat and the circumferential may, at least at the axial position of the first valve seat be circular.

[0015] The circumferential wall may e.g. be cylindrical, conical, or barrelshaped.

[0016] In a practical embodiment a pressure passage extends through the valve from the valve inlet to the second side of the first valve member. Hereby, in a manner known per se, the pressure at the valve inlet may be used for the first valve member to assume a position to provide a pressure drop between an area within the rim of the first valve member and an area outside said rim whereby the pressure difference across the flow control arrangement is kept substantially constant when the pressure difference across the entire valve from the valve inlet to the valve outlet varies.

[0017] In a practical embodiment the valve further comprises a rolling diaphragm comprising an outer rim and an inner rim, the inner rim of the rolling diaphragm being attached to the first valve member, and the outer rim of the rolling diaphragm being attached to be stationary in relation to the valve housing, said rolling diaphragm separating the first side of the first valve member from the second side of the first valve member. Hereby, in a manner known per se, it is possible to isolate the first side of the first valve member from the second side thereof to maintain the pressure difference that enables the first valve member to assume the position to provide the relevant pressure drop as mentioned above.

[0018] In a practical embodiment the flow control arrangement comprises an annular, second valve seat and a second valve member, the second valve member being movable in the axial direction and the second valve member being attached to a spindle for connection with an actuator. Hereby provisions are made for varying the flow through the valve in accordance with current needs by means of the actuator. The actuator may be manual, or it may be automatic and be controlled e.g. based on measurements of a sensor, e.g. a thermo-sensor when the valve is used in heating or cooling system.

[0019] In a further embodiment the second valve member comprises a proximal surface, said proximal surface cooperating with the second valve seat to adjust the flow of liquid through the valve. Hereby a relatively simple construction of the valve may be obtained.

[0020] It should be understood that the proximal surface of the second valve member is proximal relative to the second valve seat with which the second valve member cooperates in use.

[0021] In a still further embodiment the proximal surface of the second valve member is a proximal convex surface, said proximal convex surface being a surface of rotation around the axis, said proximal convex surface cooperating with the second valve seat to adjust the flow of liquid through the valve. Hereby a beneficial characteristic of the valve may be obtained in terms of adjustment of the flow through the valve relative to adjustment of the position of the second valve seat e.g. by means of an actuator.

[0022] In a practical embodiment the first valve seat and the second valve seat are positioned co-axially in the valve housing substantially in a common, radial plane. By the term “radial plane” should be understood a plane extending radially i.e. perpendicular relative to the axis defined above.

[0023] In a practical embodiment an axial pressure passage extends axially through the second valve member from a proximal or lower end thereof. This axial pressure passage is part of the pressure passage extending through the valve from the valve inlet to the second side of the first valve member.

[0024] While the ratio between the size of the above-mentioned annular area and the size of the likewise above-mentioned smallest inlet cross-sectional area is at least 2.4, in certain embodiments the ratio between the annular area and the smallest inlet cross-sectional area is larger than 2.4, preferably larger than 2.5, more preferably larger than 2.6, and even more preferably larger than 2.7.

[0025] Further, in certain embodiments the ratio between the size of the annular area and the size of the smallest inlet cross-sectional area is smaller than 1000, preferably smaller than 100, more preferably smaller than 10, and even more preferably smaller than 3. Keeping said ratio below certain limits it is possible to avoid that the valve is excessively large.

[0026] In a practical embodiment the valve inlet and the valve outlet are aligned on a line extending at an angle relative to the axial direction. In further embodiments said angle is in the range 30° to 90°, preferably 45° to 75°, and further preferably approx. 60°.

[0027] In the following the disclosure will be further elucidated by means of disclosure of a non-limiting example of an embodiment having reference to the accompanying drawing in which

[0028] Fig. 1 is a top view of a valve according to the present disclosure, and Fig. 2 is a view of a section along line ll-ll in Fig. 1 .

[0029] The figures show a valve 1 comprising a valve housing 2 with an axis 3 defining an axial direction through the housing 2; a valve inlet 4; and a valve outlet 5. The valve 1 further comprises a flow control arrangement 6 adapted for dynamic control of a flow of liquid through the valve; and a differential pressure regulator 7 for maintaining a substantially constant differential pressure across the flow control arrangement 6.

[0030] The flow control arrangement 6 comprises an annular, second valve seat 25 and a second valve member 26, the second valve member 26 being movable in the axial direction, and the second valve member 26 being attached to a spindle 27 for connection with an actuator. The actuator may be manual, or it may be automatic and be controlled e.g. based on measurements of a sensor, e.g. a thermo-sensor when the valve is used in heating or cooling system.

[0031] The second valve member 26 comprises a proximal surface 28, which cooperates with the second valve seat 25 to adjust the flow of liquid through the valve 1 .

[0032] In the embodiment shown the proximal surface 28 of the second valve member 26 is a proximal convex surface 28, and the proximal surface 28 is a surface of rotation around the axis 3.

[0033] The differential pressure regulator 7 comprises a cup-shaped, first valve member 8 positioned in a valve chamber 13 in the valve housing 2. The first valve member 8 comprises a rim 9 circumscribing a first area 10. In the present embodiment the rim 9 is circular and has a diameter Drwhich accordingly is also the diameter of the first area 10. The first valve member 8 is movable in the axial direction towards a first valve seat 11 in the valve chamber 13 for the rim 9 of the first valve member 8 to cooperate with the first valve seat 11 . The first valve member 8 has a first side proximal to the first valve seat 11 and an opposite, second side 12 distal from the first valve seat 11 .

[0034] In the present embodiment, apart from or disregarding the valve outlet 5, the valve chamber 13 at the rim 9 and the first valve seat 11 is defined by a circular cylindrical wall having a diameter Dc. The valve chamber 13 comprises a space 17 around the first valve member 8 and said space 17 comprising an annular area 18 coaxial with or surrounding the axis 3, The annular area 18 is positioned at the first valve seat 11 radially outside the rim 9 of the first valve member 8 and the first area 10. Thus the size of the annular area is:

[0035] Aa= TT / 4 X (Dc2- Dr2).

[0036] An inlet passage 19 is extending from the valve inlet 4 to the flow control arrangement 6, in the present embodiment that is to the second valve seat 25. The inlet passage 19 has a smallest inlet cross-sectional area 20, which in the present embodiment is a circular area having a diameter Di. Thus, in the present embodiment, the size of the smallest inlet cross-sectional area is:

[0037] A = TT / 4 x Di2

[0038] According to the present disclosure the ratio Aa / A between the size of the annular area 18 and the size of the smallest inlet cross-sectional area 20 is at least 2.4.

[0039] In the embodiment shown the differential pressure regulator 7 comprises a rolling diaphragm 22 having an outer rim and an inner rim, where the inner rim of the rolling diaphragm 22 is attached to the first valve member 8, and the outer rim of the rolling diaphragm 22 being attached to be stationary in relation to the valve housing 2. The rolling diaphragm 22 thereby separates the first side of the first valve member 8 from the second side 12 of the first valve member 8 in a manner known pe se.

[0040] In the present embodiment the first valve seat 11 and the second valve seat 25 are positioned co-axially in the valve housing 2 substantially in a common, radial plane. In the present embodiment an axial pressure passage 21 extends axially through the second valve member 26 from a proximal or lower end thereof. . This axial pressure passage 21 is part of a pressure passage extending through the valve from the valve inlet 4 to the second side 12 of the first valve member 8.

[0041] In the embodiment shown the valve inlet 4 and the valve outlet 5 are aligned on a line 30 extending at an angle relative to the axial direction, and in the embodiment shown the angle is approx. 60°.

[0042] Whereas the ratio Aa / Ai between the size of the annular area 18 and the size of the smallest inlet cross-sectional area 20 above is indicated to be at least 2.4 said ratio is in some embodiments larger than 2.4, preferably larger than 2.5, more preferably larger than 2.6, and even more preferably larger than 2.7.

[0043] Further, said ratio Aa / A is in some embodiments smaller than 1000, preferably smaller than 100, more preferably smaller than 10, and even more preferably smaller than 3.

Claims

8P A T E N T C L A I M S1 . A valve (1 ) comprising a valve housing (2) with an axis (3) defining an axial direction through the housing (2); a valve inlet (4); and a valve outlet (5), the valve (1 ) further comprising: a flow control arrangement (6) adapted for dynamic control of a flow of liquid through the valve; and a differential pressure regulator (7) for maintaining a substantially constant differential pressure across the flow control arrangement (6), wherein the differential pressure regulator (7) comprises a cupshaped, first valve member (8) positioned in a valve chamber (13) in the valve housing (2), the first valve member (8) comprising a rim (9) circumscribing a first area (10) and being movable in the axial direction towards a first valve seat (11 ) in the valve chamber (13) for the rim (9) of the first valve member (8) to cooperate with the first valve seat (11 ), the first valve member (8) comprising a first side proximal to the first valve seat (11 ) and an opposite, second side (12) distal from the first valve seat (11 ), wherein the valve chamber (13) comprises a space (17) around the first valve member (8) said space (17) comprising an annular area (18) perpendicular to the axis (3), the annular area (18) being positioned at the first valve seat (11 ) radially outside the rim (9) of the first valve member (8) and the first area (10), wherein an inlet passage (19) from the valve inlet (4) to the flow control arrangement (6) comprises a smallest inlet cross-sectional area (20), c h a r a c t e r i z e d in that a ratio between the size of the annular area (18) and the size of the smallest inlet cross-sectional area (20) is at least 2.4.

2. A valve (1 ) according to claim 1 , further comprising a rolling diaphragm (22) comprising an outer rim and an inner rim, the inner rim of the rolling diaphragm (22) being attached to the first valve member (8), and the outer rim of the rolling diaphragm (22) being attached to be stationary in relation to the valve housing (2), said rolling diaphragm (22) separating the first side of the first valve member (8) from the second side (12) of the first valve member (8).

93. A valve (1 ) according to any one of claim 1 or 2, wherein the flow control arrangement (6) comprises an annular, second valve seat (25) and a second valve member (26), the second valve member (26) being movable in the axial direction and the second valve member (26) being attached to a spindle (27) for connection with an actuator.

4. A valve (1 ) according to claim 3, wherein the second valve member (26) comprises a proximal surface (28), said proximal surface (28) cooperating with the second valve seat (25) to adjust the flow of liquid through the valve (1 ).

5. A valve (1 ) according to claim 4, wherein the proximal surface (28) of the second valve member (26) is a proximal convex surface (28), said proximal convex surface (28) being a surface of rotation around the axis (3), said proximal convex surface (28) cooperating with the second valve seat (25) to adjust the flow of liquid through the valve (1 ).

6. A valve (1 ) according to any one of claims 3 to 5, wherein the first valve seat (11 ) and the second valve seat (25) are positioned co-axially in the valve housing (2) substantially in a common, radial plane.

7. A valve (1 ) according to claim 2 and 4, wherein an axial pressure passage (21 ) extends axially through the second valve member (26) from a proximal or lower end thereof.

8. A valve (1 ) according to any one of claims 1 to 7, wherein the ratio between the size of the annular area (18) and the size of the smallest inlet cross-sectional area (20) is larger than 2.4, preferably larger than 2.5, more preferably larger than 2.6, and even more preferably larger than 2.7.

9. A valve (1 ) according to claim 8, wherein the ratio between the size of the annular area (18) and the size of the smallest inlet cross-sectional area (20) is smaller than 1000, preferably smaller than 100, more preferably smaller than 10, and even more preferably smaller than 3.

10. A valve (1 ) according to any one of claims 1 to 9, wherein the valve inlet (4) and the valve outlet (5) are aligned on a line (30) extending at an angle relative to the axial direction, preferably said angle is in the range 30° to 90°, preferably 45° to 75°, and further preferably approx. 60°.

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