Recovery actuating medium for operating control valve

Abstract

A recovery unit is configured to re-inject lost or escaped emissions back into the line. These configurations may include a pressure vessel that may hold a gas (or other fluid) that may be discharged into the atmosphere from, for example, a valve or similar flow control. The pump may be coupled with the pressure vessel. In use, the pump may draw fluid from the pressure vessel and pressurize it for injection back into the line, typically downstream of the valve. The pump may utilize upstream pressure as a power source.

Description

Background Art

[0001] Flow control devices play an important role in many industrial facilities. For example, power plants and industrial process facilities use different types of flow control to manage the flow of materials (usually fluids) throughout a vast network of pipelines, tanks, generators, and other equipment. Oil and gas facilities may employ pneumatic or electro-pneumatic control valves to regulate the flow of hydrocarbons (such as natural gas). These facilities can direct line pressure to the control valve as the operating or "actuating" medium for onboard pneumatic actuators. This feature is advantageous in remote areas because power (such as electricity) may be scarce or in short supply. However, while convenient, flow control devices may often seep or vent this actuating medium directly into the atmosphere as part of normal valve operation. Summary of the invention

[0002] The disclosed subject matter relates to improved schemes for recovering most, if not all, of this "lost" actuation medium. Of particular interest are embodiments that can collect the actuation medium and reinject it into a facility pipeline (or other portion of a facility system or network). These embodiments can use the pressure differential across the flow control element to raise the pressure of the actuation medium to a level downstream of the flow control element. This feature can prevent loss of product and reduce greenhouse gas emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] This specification refers to the following drawings:

[0004] Figure 1 A schematic diagram of the recovery unit is depicted;

[0005] Figure 2 depicts a schematic diagram of an example of a fluid circuit for use in a recovery unit;

[0006] Figure 3 depicts a schematic diagram of an example of a fluid circuit for use in a recovery unit;

[0007] Figure 4 depicts a schematic diagram of an example of a fluid circuit for use in a recovery unit;

[0008] Figure 5 Depicted Figure 3 A schematic diagram of an example of a fluid circuit; and

[0009] Figure 6 Depicts an example of a flow control.

[0010] These figures and any description herein represent examples that may disclose or explain the present invention. These examples include the best mode and also enable any person skilled in the art to practice the present invention, including making and using any device or system and performing any combined method. The drawings are not drawn to scale unless otherwise specified in the discussion. The elements in the examples may appear in one or more of the several views or in a combination of several views. The drawings may use the same reference numerals to represent the same or corresponding elements. The method is exemplary only and may be modified by, for example, reordering, adding, deleting and / or changing the various steps or stages. This specification may use the word "one" or "an" in a singular form to describe such stages and any part, component, element or function; however, this should not exclude the plural form of any such name unless the specification explicitly states or explains such exclusion. Similarly, any reference to "one embodiment" or "a specific implementation" should not exclude the existence of other implementations or specific implementations that also combine the features. DETAILED DESCRIPTION

[0011] Features of the examples shown in the above-mentioned figures will now be discussed. These features can improve compliance and revenue for operators. Operators want to reduce product losses as much as possible. They are also under tremendous pressure to reduce carbon or hydrocarbon (or greenhouse gas) emissions to comply with local regulations, or generally, to be good guardians of the environment. As noted herein, the examples show fluid loops that can capture fluids (such as natural gas) from various different locations along the operator's pipeline network. These loops prevent the natural gas from being discharged from the atmosphere, and in fact, the natural gas can be re-injected back into the pipeline network as part of normal processing operations. Other embodiments are within the scope of the present disclosure.

[0012] Figure 1 An example of a recovery unit 100 is depicted. The example resides in a distribution network 102 that is generally designed to convey material 104 through a network of conduits 106. The network 102 may include a flow control unit 108 having a valve body 110 to connect in series with the conduits 106. The device may also have an actuator 112. A valve stem 114 may extend from the actuator 112 to position a closure member 116 proximate to a seat 118. In one embodiment, the recovery unit 100 may have a fluid circuit 120 that is coupled to the conduits 106 on both sides of the flow control unit 108.

[0013] In summary, the recovery unit 100 can be configured to recover gases that are normally lost to the atmosphere. These configurations can include components that can operate on this "lost" gas. These components can, for example, capture lost gases, such as fugitive emissions or gases emitted during normal process operations. These components can also increase the pressure of the captured gas to allow the operator to reinsert the pressurized gas back into its process. These features are beneficial because the operator both prevents direct emissions of greenhouse gases and is able to generate revenue from the "re-injected" gas.

[0014] Distribution system 102 can be configured to deliver or move resources. These configurations can be embodied as a large infrastructure. Material 104 can also include gases, liquids, solids, or mixtures. Conduit 106 can include pipes or pipelines that are typically connected to pumps, boilers, etc. The pipes can also be connected to tanks or reservoirs. In many facilities, the equipment forms a complex network.

[0015] The flow control unit 108 can be configured to regulate the flow of the material 104 through the conduits 106 in these complex networks. These configurations may include control valves and similar devices. The valve body 110 in such devices is typically made of cast or machined metal. The structure may form flanges at the openings I, O. Adjacent pipes 106 may be connected to these flanges. The actuator 112 may include a pneumatic cylinder that requires the gas to be compressed or pressurized and operates in conjunction with a piston, spring, or flexible diaphragm to generate a load. The valve stem 114 may form an elongated cylinder or rod that directs the load to a closing member 116 that is typically a cylindrical block or plug. The load may control the position of the plug to prevent flow through the opening in the seat 118.

[0016] The fluid circuit 120 can be configured to couple with pressure upstream and downstream of the flow control unit 108. These configurations can include devices that can hold or retain the material 104. Other devices can pressurize the material 104. Together, these devices can form a system that allows the material 104 to flow back to the dispensing system 102.

[0017] Figure 2A schematic diagram of an example of a fluid circuit 120 is depicted. The example includes a recovery circuit 122 having components (e.g., an interface 124 and a line 126). Components 124, 126 can direct gas from or around the flow control device 108 to a pressure vessel 128, such as a tank or reservoir. In one specific implementation, the interface 124 can form an envelope around all or part of the flow control device 108. The envelope can capture "escaped" gas from the device, such as from a package, an exhaust port, or other area that can be discharged into the atmosphere. The escaped gas can enter the pressure vessel 128 through the line 126. A pump 130 can connect the pressure vessel 128 to an injection line 132, which is connected to the conduit 106 on the downstream side of the flow control device 108. The pump 130 may require power, such as an electric or pneumatic source. A control circuit 134 can be connected to the pump 130. The control circuit 134 can include a power source 136, such as a battery or a field-available mains power. The power supply 136 may energize the controller 138. In one implementation, the controller 138 may receive feedback defining operating parameters of the fluid circuit 120. These operating parameters may include, for example, a "tank" pressure, which corresponds to the pressure of the fluid in the pressure vessel 128. The controller 138 may compare the pressure to a threshold. A pressure at or above the threshold may cause the controller 138 to generate a signal P to activate the pump 130. The signal P may include an electric current or a voltage. These signals may adjust the state of the pump 130. In its "on" or operating state, the pump 130 may draw the fugitive gas from the pressure vessel 128. The pump 130 may increase the pressure of the fugitive gas, for example, to allow the fugitive gas to flow back into the conduit 106 through the injection line 132 at the same or similar pressure as downstream of the flow control unit 108. The controller 138 may, for example, in response to the tank pressure being at or below the threshold, turn the pump 130 to its "off" or non-operating state. This state allows the fugitive gas to fill the pressure vessel 128.

[0018] Figure 3A schematic diagram of another example of a fluid circuit 120 is depicted. The pump 130 may be embodied as a pneumatic pump, which requires a pneumatic logic 140 having a flow component such as a check valve 142, a pressure regulator 144, or a valve 146. The components 144, 146 may be connected to a source line 148 that carries pressure from the conduit 106 connected to the upstream side of the flow control unit 108. The pressure may be used to drive or operate the pneumatic pump 130. In one specific implementation, the controller 138 may manipulate the signal P in response to the relationship between the tank pressure and a threshold value. This feature may cause the valve 146 to change state between its "open" state and its "closed" state. The open state may allow pressure to energize the pneumatic pump 130, for example, to draw the escaping gas from the pressure vessel 128, pressurize it, and inject it back into the conduit 106 through the injection line 132 at the same or similar pressure as downstream of the flow control unit 108. The closed state may prevent pressure from the pneumatic pump 130. This feature may shut off the pump to allow the escaping gas to fill the pressure vessel 128 .

[0019] Figure 4 A schematic diagram of another example of a fluid circuit 120 is depicted. The pump 130 may be embodied as an ejector or similar vacuum pump. The ejector 130 may include a high pressure inlet (HP) coupled to a valve 146. A low pressure inlet (LP) may be coupled to a pressure vessel 128. When in use, the high pressure flow through the ejector 130 may create a vacuum that draws fluid from the pressure vessel 128 into the device. This feature evacuates the pressure vessel 128. The device may be further configured to mix the high pressure flow and the low pressure flow together. The combined flow leaves the ejector 130 at its intermediate pressure outlet (IP) and is injected back into the conduit 106 through the injection line 132 at the same or similar pressure as downstream of the flow control unit 108.

[0020] Figure 5 Depicted Figure 3 1 is a schematic diagram of an example of a fluid circuit 120 of FIG. The example includes a sensing line 150 and an instrument line 152 having a pressure regulator 154. Both lines 150, 152 can be coupled to a valve instrument 156. The sensing line 150 can couple the valve instrument 156 to the conduit 106 on the downstream side of the flow control unit 108. This arrangement can provide feedback about downstream pressure, which is important for adjusting the position of the closing member 116 to ensure that the material 104 flows properly through the device. The instrument line 152 can allow pressure from the upstream side of the flow control unit 108 to operate the actuator 112. In one embodiment, the pressure regulator 154 can significantly reduce the pressure of the incoming gas, for example from 1000 psi to approximately 120 psi, for the flow control unit 108.

[0021] Figure 6A perspective view of an exemplary structure of a flow control unit 108 is depicted. The structure may include a valve travel sensor 158 fixed to a mounting member 160. The mounting member 160 may be coupled to a base 162, for example, by a fastener F (such as a screw or bolt). The base 162 may support the valve body 110. As also shown, the base 162 may support a load generator 164, which may include a spring barrel 166 and a pneumatic cylinder 168. In one embodiment, the valve instrument 156 may be embodied as a controller that senses downstream pressure. The controller 156 may act on the pneumatic cylinder 168 to move the closing member 116 ( Figure 1 ) is positioned in its correct position, thereby maintaining the downstream pressure at a desired or predetermined level. Other components, such as a travel scale 170, may also be fastened to the base 162. The travel scale 170 may be embodied as part of a mechanical indicator having one or more parts that are mounted to the base 162 or integrated into the base as a machined feature. However, the present disclosure also contemplates the use of display technology (e.g., a screen, a display, etc.) that may provide an observer with some type of visual interface to achieve the closing member 26 ( Figure 1 )’s movement or position.

[0022] In view of the foregoing, the improvements herein reduce the amount of natural gas (or other actuating medium) that is vented into the atmosphere by the flow control. These improvements may allow operators to comply with local regulations or standards. As an additional benefit, the proposed design may re-inject the escaping gas back into the facility pipeline. This feature allows operators to profit from a product that is typically "lost" as part of normal process or facility operations.

[0023] The following examples include certain elements or clauses describing the embodiments contemplated within the scope of this specification. These elements may be combined with other elements and clauses to further describe the embodiments. This specification may include and contemplate other examples that occur to those skilled in the art. If these other examples have structural elements that are indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are indistinguishable from the literal language of the claims, these other examples fall within the scope of the claims.

Claims

1. A recovery unit, comprising: a recovery circuit having a port for capturing fluid from an envelope disposed about the valve; a pressure vessel, the pressure vessel being coupled to the recovery loop; and A pump is coupled to the pressure vessel, the pump being configured to draw fluid from the pressure vessel and produce a flow at a pressure corresponding to a pressure downstream of the valve.

2. The recycling unit according to claim 1, further comprising: A control circuit is coupled to the pressure vessel and the pump, the control circuit being configured to generate a signal to activate and deactivate the pump in response to pressure in the pressure vessel.

3. The recycling unit according to claim 1, further comprising: A control circuit is coupled to the pressure vessel and the pump, the control circuit being configured to generate an electrical signal to activate the pump in response to the pressure in the pressure vessel.

4. The recycling unit according to claim 1, further comprising: A control circuit is coupled to the pressure vessel and the pump, the control circuit being configured to generate a pneumatic signal to activate and deactivate the pump in response to pressure in the pressure vessel.

5. The recycling unit according to claim 1, further comprising: A control circuit is coupled to the pressure vessel and the pump, the control circuit comprising a valve between a controller and the pump.

6. The recycling unit according to claim 1, further comprising: A control circuit is coupled to the pressure vessel and the pump, the control circuit including a controller, a valve between the controller and the pump, and a pressure regulator coupled to an upstream side of the controller.

7. The recycling unit according to claim 1, further comprising: A control circuit is coupled to the pressure vessel and the pump, the control circuit including a controller, a valve between the controller and the pump, and a pressure regulator coupled to an upstream side of the controller.

8. The recycling unit according to claim 1, further comprising: An injection line is coupled to the pump at a first end to receive the flow, the injection line being configured with a second end to couple to a conduit coupled to a downstream side of the valve.

9. The recovery unit of claim 1, wherein the pump comprises an electric pump.

10. The recovery unit of claim 1, wherein the pump comprises a pneumatic pump.

11. The recovery unit of claim 1 , wherein the pump comprises an ejector.

12. A system, comprising: a pressure vessel having a connector engageable with a portion of a valve, the connector being configured to direct fugitive gas exhaust from the portion of the valve into the pressure vessel; and A pumping system is coupled to the pressure vessel, the pumping system comprising a pump and a control loop for operating the pump, the control loop being configured to generate a signal in response to feedback from the pressure vessel, the signal causing the pump to discharge a flow comprising a fluid from the pressure vessel.

13. The system of claim 12, wherein the signal is a pneumatic signal. The system of claim 12 , wherein the signal is an electrical signal.

15. The system of claim 12, wherein the signal causes a valve to open or close.

16. A method comprising: directing fugitive emissions from the valve into the pressure vessel; energizing a pump in response to pressure in the pressure vessel; as well as Flow is directed from the pump to the downstream side of a flow control unit provided as part of the pipeline.

17. The method according to claim 16, further comprising: Fluid is directed from an upstream side of the flow control device to the pump.

18. The method according to claim 16, further comprising: directing fluid from an upstream side of the flow control device to the pump; as well as A valve is actuated to allow the fluid to flow to the pump.

19. The method of claim 16, wherein the pressure of the stream corresponds to the pressure of the fluid in the pipeline.

20. The method of claim 16, wherein the pump comprises an ejector.

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