flow switch

Abstract

A flow switch (110) includes a base body (10), an orifice body (20) movable relative to the base body (10), and a spring (30) associated with the orifice body (20). The orifice body (20) is provided with an aperture (42) that varies in size with movement of the orifice body (20). In an exemplary embodiment, a protrusion (40), such as a rod, is fixed relative to the base body (10); the spring (30) is configured such that, at a first volumetric flow rate, the protrusion (40) at least distally passes through the aperture (42); at a second volumetric flow rate higher than the first volumetric flow rate, the protrusion (40) is entirely outside the orifice body (20).

Description

[0001] This application claims priority to U.S. Patent Application No. 18 / 425,548, filed January 29, 2024, the disclosure of which is incorporated herein by reference as if fully restated herein. Technical Field

[0002] Exemplary implementations generally relate to flow switches, such as flow switches with variable orifice openings to reduce pressure drop, and related systems and methods. Background Technology

[0003] Flow switches are known devices typically used to monitor volumetric flow rates. These switches generally output an electrical signal when the volumetric flow rate exceeds a predetermined upper threshold and / or falls below a predetermined lower threshold (e.g., deviates from a predetermined allowable range). However, the pressure drop across the orifice of such flow switches typically increases exponentially with increasing flow rate. In some applications, such as when the volumetric flow rate operating range is much higher than the switch's actuation point, the large pressure drop renders conventional flow switches unusable. These applications include, but are not limited to, emergency shutdowns before pump dry running. While increasing the orifice opening can reduce the pressure drop, it can result in excessively low pressure drops in the lower flow rate range, causing unreliable flow switch operation. Therefore, the industry urgently needs a flow switch that can operate stably over a wider volumetric flow rate range. Summary of the Invention

[0004] This document provides a flow switch capable of reliable operation over a wide volumetric flow rate range. The flow switch may feature a variable orifice, for example, located on the orifice body. In a non-limiting exemplary embodiment: the flow switch is configured to form a relatively small orifice at lower volumetric flow rates, achieving high-precision switching action; and to form a relatively larger orifice at higher volumetric flow rates, minimizing pressure drop. In the exemplary embodiment, a protrusion (e.g., a rod) may be provided, which can selectively extend into or retract from the orifice. By way of example, and not limitation: at higher volumetric flow rates, the fluid pushes the orifice body to compress the spring, causing the protrusion to separate from the opening of the orifice body, increasing the orifice flow area and reducing pressure drop; at lower volumetric flow rates, the spring pushes the orifice body forward, causing the opening to cover at least a portion of the protrusion, forming a smaller orifice and achieving more precise switching triggering. Preferably, the end of the protrusion is tapered to avoid abrupt changes in the orifice flow area and the resulting oscillations.

[0005] The following sections will describe in detail, with reference to the accompanying drawings, further features and advantages of the systems and methods disclosed herein, as well as the construction and operation of the various structures of this disclosure. Attached Figure Description

[0006] In addition to the features described above, other aspects of the invention will become clear from the accompanying drawings and exemplary embodiments described below. In the multiple views, the same reference numerals refer to the same, similar, or equivalent structures, wherein: Figure 1: Side cross-sectional view of a prior art flow switch; Figure 2A Figure 1 shows the idealized voltage drop-flow rate relationship curve under the exemplary operating condition of the flow switch. Figure 2B Figure 1 shows an idealized pressure drop-flow rate curve under another exemplary operating condition of the flow switch. Figure 3 : A side cross-sectional view of a flow switch according to an embodiment of the present invention; Figure 4A : Figure 3 A partial side cross-sectional view of the flow switch, with the protrusion in a first exemplary position; Figure 4B : Figure 3 A partial side cross-sectional view of the flow switch, with the protrusion in a second exemplary position; Figure 5 : Figure 3 Idealized pressure drop-flow rate curve under exemplary operating conditions of the flow switch; Figure 6 : Figure 3 Flow switch operation Figures 4A-4B Idealized relationship curve between orifice opening and body position under operating conditions. Detailed Implementation

[0007] The various embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Specific details such as detailed structures and components are used only to aid in a comprehensive understanding of the embodiments of the present invention. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the spirit and scope of the present invention. Furthermore, to ensure brevity and clarity, well-known functions and structures will not be repeated.

[0008] This document describes the embodiments of the present invention in conjunction with the accompanying drawings of the idealized embodiments (and intermediate structures). Accordingly, it is normal for the actual structure to deviate from the shape shown in the drawings due to factors such as processing technology and manufacturing tolerances. Therefore, the embodiments of the present invention are not limited to the specific shape of the area shown in the drawings, but should also include shape deviations caused by manufacturing processes.

[0009] Figure 1 illustrates a prior art flow switch 10. When fluid flows through or contacts the flow switch 10, the fluid passes through the throttling orifice body 2 on the base body 1. The fluid can be any medium (oil, water, air, etc.). The fluid force can push the throttling orifice body 2 to move against the spring 3; the direction of the spring force of the spring 3 is opposite to the preset flow direction of the fluid. When the volumetric flow rate reaches a set value, the displacement of the throttling orifice body 2 is large enough to cause the switch 5 to close. In an exemplary embodiment, a magnet is connected or integrated on the throttling orifice body 2; when the throttling orifice body 2 generates sufficient displacement, it drives the switch 5 to close or open; the switch can be a reed switch, which can be preset to a bias state (normally open or normally closed). The state (on / off) electrical signal of the switch 5 is output externally through wires and / or sensors within the electronic component 6. Other known on / off and signal output schemes can also be used.

[0010] The pressure drop across the orifice body 2 typically increases exponentially with increasing flow rate. Figure 2A For example (non-restrictive): If the switch actuation point X is located in the middle or high range of the switch's operating range (Q1~Q2), the voltage drop generally will not cause a problem. Figure 2B For example (non-limiting): When the expected operating range of the fluid (Q1' to Q2') is much higher than the switch actuation point X' (e.g., reaching 150%, 3 times or more of the actuation point flow rate), the huge pressure drop generated under high volumetric flow rate will render the flow switch 10 unusable. Typical application scenarios include, but are not limited to: emergency shutdown protection for pump dry running.

[0011] Figure 3 This invention provides an exemplary flow switch 110. Components with similar structures are numbered 10 accordingly (e.g., 2 becomes 20, 10 becomes 110, and so on). When fluid flows through the flow switch 110, it passes through the orifice body 20 on the base body 10. The fluid can be any medium (oil, water, air, etc.). The fluid thrust pushes the orifice body 20 to move against the spring 30; the spring force of the spring 30 is opposite to the preset flow direction of the fluid. When the volumetric flow rate reaches a set value, the orifice body 20 is sufficiently displaced, causing the switch 50 to close. In an exemplary embodiment, the orifice body 20 is connected to or integrated with a magnet; when the orifice body 20 is sufficiently displaced, it drives the switch 50 to open or close; the switch can be a reed switch, which can be preset to a bias state (normally open / normally closed). The switch 50 state (on / off) electrical signal is output through wires and / or sensors within the electronic component 60. Other known on / off and signal output methods can also be used.

[0012] The flow switch 110 can change the flow area of ​​the orifice 42 in the orifice body 20 according to the volumetric flow rate. A protrusion 40 is provided, preferably fixed relative to the base body 10, allowing the orifice body 20 to move relative to the protrusion 40; the protrusion 40 can be a rod. During normal operation, the flow switch 110 displaces the orifice body 20, causing the orifice 42 to move forward or backward relative to the protrusion 40, thereby changing the flow area of ​​the orifice 42. This is an example, not a limitation: such as... Figure 4A As shown, the orifice body 20 covers the protrusion 40 forward, reducing the flow area of ​​the opening 42. This operating condition corresponds to a lower volumetric flow rate: the orifice body 20 is pushed forward by the preload of the spring 30. Another example (non-limiting): as... Figure 4B As shown, the orifice body 20 retracts relative to the protrusion 40, increasing the flow area of ​​the orifice body 20 opening 42. This operating condition corresponds to a higher volumetric flow rate: the fluid force compresses the spring 30. The orifice body 20 has sufficient stroke: at low volumetric flow rates, at least a portion of the protrusion 40 extends into the orifice body 20; at high volumetric flow rates, the protrusion 40 separates from the orifice body 20.

[0013] Preferably, the distal end 44 of the protrusion 40 is provided with a conical surface to achieve a continuous change in the flow area of ​​the opening 42, avoiding abrupt changes in the opening size and the resulting oscillations. The cross-section of the main body 46 of the protrusion 40 remains basically consistent (error ≤10%).

[0014] The protrusion 40, in the form of a rod (with or without the tapered end 44), is merely an example; its size and shape are not limited. Similarly, the shapes of the throttling orifice body 20 and the opening 42 shown are also merely examples and do not constitute limitations. The throttling orifice body 20 can be a hollow cylinder or other shapes; the opening 42 can be circular or other shapes. In this case, the shape of the protrusion 40 can match the shape of the opening 42. Protrusions or components of other sizes and shapes can be used.

[0015] The protrusion 40 can be fixed relative to the base body 10 (directly or indirectly). Regardless of the installation method, the orifice body 20 can move relative to the protrusion 40. Due to this structure: at high volumetric flow rates, the fluid pushes the orifice body 20 away from the protrusion 40, naturally increasing the flow area of ​​the opening 42; when the flow rate is sufficiently high, the two completely separate (see...). Figure 4B At low volumetric flow rates, the orifice body 20 moves towards the protrusion 40 and covers the protrusion, naturally reducing the flow area of ​​the opening 42 (see...). Figure 4B ).

[0016] The arrangement of the protrusion 40 relative to the opening 42 is merely an example and is not limited. Various relative positions can be used: the protrusion always at least partially passes through the opening 42; the protrusion is completely outside the throttling orifice body 20; a portion of the protrusion is inside the throttling orifice body 20; the vast majority (>90%) of the protrusion is inside the throttling orifice body 20; and combinations of the above. The stiffness of the spring 30, the dimensions and relative positions of the throttling orifice body 20, the dimensions and relative positions of the protrusion 40, or combinations of the above parameters can be adjusted accordingly.

[0017] Figure 5 The typical relationship curve between the voltage drop and flow rate of the flow switch 110 is shown. The dashed line represents the characteristics of the existing flow switch 10, and the solid line represents the characteristics of the flow switch 110 of the present invention with a variable orifice 42. As shown in the figure: In the high volumetric flow rate range, the voltage drop of the flow switch 110 is significantly reduced; at the same time, more precise switching action can be achieved in the low flow rate range. Therefore, the flow switch 110 can adapt to a wider operating range (e.g., Q1'' to Q2''). In the high flow rate range, although the overall voltage drop of the flow switch 110 still increases with the flow rate, the voltage drop is much lower than that of the existing flow switch 10 due to the enlarged orifice 42 of the throttling orifice body 20.

[0018] Figure 6 The correspondence between the area (A) of the opening 42 and the position (S) of the throttling orifice body 20 is shown in the form of a curve.

[0019] The curves in the accompanying figures are idealized examples used to help understand the principles and do not constitute a limitation.

[0020] This solution can be applied to other types of flow switches 110; at the same time, components of other sizes and shapes can be used to replace the protrusions 40.

[0021] Any embodiment of this invention can be combined with any technical feature of other embodiments. The exemplary embodiments disclosed herein are not exhaustive and are not intended to unduly limit the scope of protection of this invention. The exemplary embodiments were selected and described to illustrate the principles of this invention and enable those skilled in the art to implement it. After demonstrating and explaining the exemplary embodiments of this invention, those skilled in the art will recognize that numerous changes and modifications can be made to this invention; most modifications achieve the same effect and fall within the scope of the inventive concept described in the claims.

[0022] Some of the operations described herein can be performed by one or more electronic devices. Each electronic device may include one or more processors, electronic memory, executable software instructions, or combinations thereof, configured to implement the operations described herein. Electronic devices may be general-purpose computers or special-purpose computing devices, including personal computers, smartphones, tablets, databases, servers, etc. The electrical connections and signal transmissions described herein can be implemented through wired / wireless communication components (routers, modems, network cables, fiber optic cables, telephone lines, signal repeaters, etc.) and / or networks (Internet, corporate intranets, cellular networks, World Wide Web, local area networks, etc.). The computer hardware, software, components, systems, steps, methods, and processes described herein can improve the operating efficiency of the entire computer system. The electronic devices (including electronic memory, databases, controllers, etc.) store and transmit only non-transitory signals.

[0023] The following numbered descriptions form part of this disclosure: Description 1: A flow switch, comprising: Base body; The orifice body is movable relative to the base body; and A spring is connected to the throttling orifice body; The orifice body is provided with an opening, the size of which is variable as the orifice body moves relative to the orifice body.

[0024] Note 2: The flow switch according to Note 1 further includes: a protrusion fixed relative to the orifice body; wherein, when the orifice body is in the first position, the protrusion extends at least partially through the opening on the orifice body; when the orifice body is in the second position, the protrusion is completely located outside the orifice body.

[0025] Note 3: According to the flow switch described in Note 2, wherein: The spring applies a biasing force to the orifice body, such that the orifice body is located in a first position at a first volumetric flow rate and in a second position at a second volumetric flow rate; wherein the second volumetric flow rate is greater than the first volumetric flow rate.

[0026] Note 4: According to the flow switch described in Note 3, the protrusion includes a rod.

[0027] Note 5: According to the flow switch described in Note 4, wherein the rod has a tapered end.

[0028] Note 6: According to the flow switch described in Note 5, wherein: The rod has a circular cross-section; and The conical end is roughly conical in shape.

[0029] Note 7: According to the flow switch described in Note 4, wherein: The spring is directly connected to the orifice body; and The protrusion is fixedly installed on the base body.

[0030] Note 8: The flow switch according to Note 1 further includes: A switch, for actuating when the orifice body moves; and The electronic component is electrically connected to the switch.

[0031] Description 9: A flow switch, comprising: The base body is used for fluid flow; The throttling orifice body is movable relative to the base body, and the throttling orifice body is provided with an opening; A spring, connected to the orifice body, and offset relative to the intended flow direction of the fluid through the base body; and A protrusion is fixed relative to the base body; wherein the spring is configured such that: at a first volumetric flow rate, at least the distal end of the protrusion extends through the opening into the orifice body; and at a second volumetric flow rate higher than the first volumetric flow rate, the protrusion is completely located outside the orifice body.

[0032] Note 10: According to the flow switch described in Note 9, wherein: The throttling orifice body is plastically deformed into a hollow cylinder; The opening is circular; and The protrusion is roughly cylindrical.

[0033] Note 11: The flow switch according to Note 10, wherein: The distal portion of the body tapers in a roughly tapered shape.

[0034] Note 12: According to the flow switch described in Note 9, wherein: The protrusion includes a rod that is fixedly installed on the base body.

[0035] Note 13: The flow switch according to Note 9 further includes: A switch, for actuating when the orifice body moves; and The electronic component is electrically connected to the switch.

[0036] Note 14: The flow switch according to Note 9, wherein: The spring is directly connected to the throttling orifice body and biases the throttling orifice body toward the protrusion.

[0037] Description 15: A method for operating a flow switch, comprising: The flow switch is positioned in the fluid flow path; the flow switch includes: Base body; The orifice body is movable relative to the base body; and A spring is connected to the throttling orifice body; The orifice body is provided with an opening, and the size of the opening is variable as the orifice body moves. Fluid with a first volumetric flow rate is introduced to form the opening into a first size; and A fluid with a second volume flow rate higher than the first volume flow rate is introduced, causing the opening to form a second size larger than the first size.

[0038] Note 16: According to the method described in Note 15, wherein: The flow switch includes a protrusion fixed relative to the orifice body; and The flow switch is configured such that, under the first volumetric flow rate, the orifice body extends beyond the main body of the protrusion; under the second volumetric flow rate, the orifice body and the protrusion separate from each other.

[0039] Note 17: According to the method described in Note 16, wherein the protrusion includes a rod.

[0040] Note 18: The method according to Note 17, wherein: the rod has a tapered end.

[0041] Note 19: According to the method described in Note 18, the protrusion is fixedly installed on the base body.

[0042] Note 20: The method described according to Note 15 further includes: During the fluid flow, a signal characterizing the state of the flow switch is received from the flow switch; wherein the flow switch includes: A switch, for actuating when the orifice body moves; and The electronic component is electrically connected to the switch.

Claims

1. A flow switch, comprising: Base body; The orifice body is movable relative to the base body; as well as A spring is connected to the throttling orifice body; The orifice body is provided with an opening, the size of which is variable as the orifice body moves relative to the orifice body.

2. The flow switch according to claim 1, further comprising: The protrusion is fixed relative to the base body; When the orifice body is in the first position, the protrusion extends at least partially through the opening on the orifice body; when the orifice body is in the second position, the protrusion is completely located outside the orifice body.

3. The flow switch according to claim 2, characterized in that: The spring applies a biasing force to the orifice body, such that the orifice body is located in a first position at a first volumetric flow rate and in a second position at a second volumetric flow rate; wherein the second volumetric flow rate is greater than the first volumetric flow rate.

4. The flow switch according to claim 3, characterized in that: The protrusion includes a rod.

5. The flow switch according to claim 4, characterized in that: The rod has a tapered end.

6. The flow switch according to claim 5, characterized in that: The rod has a circular cross-section; and The tapered end is roughly conical in shape.

7. The flow switch according to claim 4, characterized in that: The spring is directly connected to the orifice body; and The protrusion is fixedly installed on the base body.

8. The flow switch according to claim 1, further comprising: A switch, used to operate when the orifice body moves; as well as The electronic component is electrically connected to the switch.

9. A flow switch, comprising: The base body is used for fluid flow; The throttling orifice body is movable relative to the base body, and the throttling orifice body is provided with an opening; A spring, connected to the orifice body, is offset relative to the expected flow direction of the fluid through the base body; as well as A protrusion is fixed relative to the base body; wherein the spring is configured such that: at a first volumetric flow rate, at least the distal end of the protrusion extends through the opening into the orifice body; and at a second volumetric flow rate higher than the first volumetric flow rate, the protrusion is completely located outside the orifice body.

10. The flow switch according to claim 9, characterized in that: The throttling orifice body is plastically deformed into a hollow cylinder; The opening is circular; and The protrusion is roughly cylindrical.

11. The flow switch according to claim 10, characterized in that: The distal portion of the body tapers in a roughly tapered shape.

12. The flow switch according to claim 9, characterized in that: The protrusion includes a rod that is fixedly installed on the base body.

13. The flow switch according to claim 9, further comprising: A switch, used to operate when the orifice body moves; as well as The electronic component is electrically connected to the switch.

14. The flow switch according to claim 9, characterized in that: The spring is directly connected to the throttling orifice body and biases the throttling orifice body toward the protrusion.

15. A method for operating a flow switch, comprising: The flow switch is placed in the fluid flow path; The flow switch includes: Base body; The orifice body is movable relative to the base body; and A spring is connected to the throttling orifice body; The orifice body is provided with an opening, and the size of the opening is variable as the orifice body moves. Fluid with a first volumetric flow rate is introduced to form the opening into a first size; and A fluid with a second volume flow rate higher than the first volume flow rate is introduced, causing the opening to form a second size larger than the first size.

16. The method according to claim 15, characterized in that: The flow switch includes a protrusion fixed relative to the orifice body; and The flow switch is configured such that, under the first volumetric flow rate, the orifice body extends beyond the main body of the protrusion; under the second volumetric flow rate, the orifice body and the protrusion separate from each other.

17. The method according to claim 16, characterized in that: The protrusion includes a rod.

18. The method according to claim 17, characterized in that: The rod has a tapered end.

19. The method according to claim 18, characterized in that: The protrusion is fixedly installed on the base body.

20. The method of claim 15, further comprising: During the fluid flow, a signal characterizing the state of the flow switch is received from the flow switch. The flow switch includes: A switch, for actuating when the orifice body moves; and The electronic component is electrically connected to the switch.

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