Gas recovery systems having hydraulic loops

Abstract

Example gas recovery systems having hydraulic loops are disclosed herein. An example gas recovery system includes a first pump to be fluidly coupled between a high pressure gas line and a low pressure gas line of a facility. The first pump is to be driven by a pressure differential between the high pressure gas line and the low pressure gas line. The gas recovery system includes a second pump to be fluidly coupled between a bleed gas source and the low pressure gas line. The second pump is to, when activated, transfer gas from the gas source to the low pressure gas line. The gas recovery system includes a hydraulic loop. The first is pump to, when activated, drive hydraulic fluid through the hydraulic loop. The hydraulic fluid is used to power the second pump.

Description

GAS RECOVERY SYSTEMS HAVING HYDRAULIC LOOPSFIELD OF THE DISCLOSURE

[0001] This disclosure relates generally to gas recovery systems and, more particularly, to gas recovery' systems having hydraulic loops.BACKGROUND

[0002] Facilities such as buildings, manufacturing plants, factories, etc. commonly use natural gas for various purposes such as for heating (e.g., air heating, water heating, etc.), power generation, transportation, etc. Gas is routed through various lines (e.g., pipes) throughout the facility. In some instances, valves and other equipment are operated by a portion of the gas as a means of pneumatic pressure. The valves and other equipment vent the natural gas to the atmosphere. This venting of the gas to the atmosphere is wasteful and can be harmful to the environment.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] FIG. 1 is a schematic diagram of an example gas recovery system implemented in connection with a facility and including two example pumps and an example hydraulic loop.

[0004] FIG. 2 is a more detailed schematic diagram of the example gas recovery' system of FIG. 1.

[0005] FIG. 3 is a schematic diagram of an example pump that can be implemented in the example gas recovery system of FIGS. 1 and 2.

[0006] FIG. 4 is a schematic diagram of the example gas recovery' system of FIG. 1 in which compressed air is used to power the first pump.

[0007] In general, the same reference numbers will be used throughout the drawing(s) and accompanying written description to refer to the same or like parts. The figures are not to scale. Instead, the thickness of the layers or regions may be enlarged in the drawings. Although the figures show' layers and regions with clean lines and boundaries, some or all of these lines and / or boundaries may be idealized. In reality, the boundaries and / or lines may be unobservable, blended, and / or irregular.DETAILED DESCRIPTION

[0008] Disclosed herein are example gas recovery systems that can be used to collect and transfer gas from a gas source (e.g., bleed or vent gas) to a gas line. Many facilities (e.g., buildings, manufacturing plants, refineries, etc.) include one or more natural gas lines of different pressures. Many devices, such as valves, regulators, switches, etc. are operated using pressurized gas from the gas lines. After being used by the devices, the gas is typically vented to the atmosphere. This venting is wasteful and potentially harmful to the environment. The example gas recovery systems disclosed herein can be used to collect gas from one or more devices and re-inject the gas back into one or more of the gas lines, thereby reducing or preventing wasted gas and harmful emissions to the atmosphere.

[0009] An example gas recovery system disclosed herein includes a first pump that drives hydraulic fluid through a hydraulic loop. The gas recovery system includes a second pump that is driven or powered by the hydraulic fluid in the hydraulic loop. The second pump is fluidly coupled between the gas source and one of the gas lines. As such, when the system is activated, the second pump can pump and / or otherwise transfer gas from the gas source to the gas line. In some examples, the first pump is driven by a pressure differential between a high pressure gas line and a low pressure gas line. Therefore, natural gas is used to drive the first pump, which drives hydraulic fluid through the hydraulic loop, which drives the second pump to perform the gas recovery operation.

[0010] The benefit of using the hydraulic loop is that hydraulic fluid can be used to operate the various devices (e g., valves, pressure sensors, switches, etc.) in the system, and then returned back to the hydraulic loop. Therefore, no hydraulic fluid or natural gas is vented or lost to the atmosphere. Further, the example systems disclosed herein may be operated entirely by pneumatics and hydraulics. In other words, the example system may not use any electronic components. Because natural gas is combustible, it is advantageous to avoid use of electrical components that could cause a spark in the vicinity of the combustible fluid. The example gas recovery system can operate entirely autonomously using pneumatic and hydraulic power. Further, because the example system does not require electrical power, the example system can continue to operate even in the event of a power outage at the facility.

[0011] The example systems disclosed herein refer to various gas and hydraulic lines. The lines may be implemented as any ty pe of line, hose, tube, pipe, fluid connector, etc. for routing fluid between two locations. The lines can also be implemented as passageways, channels, and / or openings in a structure (e.g., a device body) that allows fluid flow between two locations.

[0012] FIG. 1 is a schematic of an example gas recovery' system 100 implemented in an example facility 102 having a high pressure gas line 104 and a low pressure gas line 106. The example gas recovery system 100 utilizes a pressure differential between the high pressure gas line 104 and the low pressure gas line 106 to operate one or more pumps for transferring gas from a bleed gas source 108 to another location, such as to the low pressure gas line 106. The facility 102 can represent any facility that utilizes natural gas. such as a manufacturing facility, a power plant, a refinery, an office building, etc. Many facilities have gas lines with higher and lower pressures. For example, the high pressure gas line 104 may carry natural gas at about 1000 pounds-per-square-inch (psi), while the low pressure gas line 106 may cany' natural gas at about lOOpsi. The high and low pressure gas lines 104, 106 may route gas to various equipment in the facility 102 such as heaters, gas power generators, etc. In some examples, the facility 102 may have additional gas lines at other pressures. In some examples, natural gas is provided to the facility 102 by a single gas line at a certain pressure, and the facility 102 provides devices (e.g., a pressure regulator, a compression station) for splitting the gas into various gas lines or manifolds at different pressures for use throughout the facility’ 102.

[0013] The bleed gas source 108 can correspond to one or more gas-operated devices that utilize gas pressure (e.g., from the high pressure gas line 104 and / or the low pressure gas line 106) to operate. For example, the gas-operated device(s) can include valves, actuators, switches, sensors, and / or other flow control devices that may be operated using the pressurized gas. In particular, a valve and / or valve controller may operate by extracting a small amount of pressurized gas from the high and / or low pressure gas lines 104, 106 and use the pressure to operate (e.g., open, close) the valve. However, in known systems, after this small amount of pressurized gas is used to operate the device (e.g., actuate a valve), the gas is vented to the atmosphere (e.g.. as a puff of gas). Over time, these small releases of gas into the atmosphere add up to a relatively large amount of gas being vented to the atmosphere. The release of such bleed gas to the atmosphere can be wasteful and harmful to the environment and / or may pose a safety' concern due to a risk of accidental combustion. Therefore, instead of releasing the bleed gas to the atmosphere, the example gas recovery system 100 can be used to capture and transfer the gas from these gas-operated device(s) and re-inject the gas into another location. In the illustrated example, the gas recovery' system 100 injects the gas into the low pressure gas line 106, but in other examples could inject the gas into the high pressure gas line 104. Therefore, the example gas recovery system 100 reduces and / or prevents harmful emissions into the atmosphere.

[0014] In the illustrated example, the gas recovery system 100 includes a first pump 110 and a second pump 112, which may also be referred to as compressors. Each of the pumps 110, 112 has a driving side or portion and a driven side or portion. The driving side powers or drives the driven side. As discussed in further detail herein, the first pump 110 is a gas-driven hydraulic pump, and the second pump 112 is a hydraulic-driven gas pump.

[0015] The gas recovery system 100 includes a first gas line 114 that fluidly couples the high pressure gas line 104 to an inlet of the driving side of the first pump 110, and a second gas line 116 that fluidly couples an outlet of the driving side of the first pump 110 to the low pressure gas line 106. As such, the driving side of the first pump 110 is fluidly coupled between the high pressure gas line 104 and the low pressure gas line 106. The first pump 110 uses the pressure differential between the high pressure gas and the low pressure gas to power or drive the driving side of the first pump 110, which in turn drives or powers the driven side of the first pump 110.

[0016] In the illustrated example, the gas recovery system 100 includes a hydraulic loop 118 that contains hydraulic fluid. The driven side of the first pump 110 drives hydraulic fluid through the hydraulic loop 1 18. This hydraulic fluid is used to power or drive the second pump 112. For example, as shown in FIG. 1, the hydraulic loop 118 includes a first hydraulic line 120 that fluidly couples an outlet of the driven side of the first pump 110 and an inlet of the driving side of the second pump 112, and a second hydraulic line 122 that fluidly couples the outlet of the driving side of the second pump 112 and the inlet of the driven side of the first pump 110. The first and second hydraulic lines 120 form the hydraulic loop 118. When the first pump 110 is activated, the first pump 110 drives or pumps hydraulic fluid through the hydraulic loop 118 to power the second pump 112.

[0017] The second pump 112 is used to pump and / or otherwise transfer gas from the bleed gas source 108 to the low pressure gas line 106. As show n in FIG. 1, a first bleed line 124 fluidly couples the bleed gas source 108 and an inlet of the driven side of the second pump 112, and a second bleed line 126 fluidly couples the outlet of the driven side of the second pump 112 and the low pressure gas line 106. Therefore, while the second pump 112 is activated (e.g., being powered by the hydraulic fluid), the second pump 112 operates to transfer gas from the bleed gas source 108 to the low pressure gas line 106.

[0018] While some known gas recovery7systems may utilize only one pump to directly pump gas from the bleed gas source 108 to the low pressure gas line 106, the example gas recovery system 100 includes the hydraulic loop 118 that is used to power the second pump 112. The advantage of having the hydraulic loop 118 is that the hydraulic pressure can be used tooperate other devices of the gas recovery' system 100 such as valves, sensors, switches, etc. Hydraulic pressure is often viewed as more stable and controllable and. thus, is preferred for operating such devices. For example, as shown in FIG. 1, hydraulic fluid from the hydraulic loop 118 can be used by one or more sensing / controlling devices 128 of the gas recovery system 100. The sensing / controlling devices 128 can include various types of devices such as valves, switches, sensors, etc. These devices are used to operate and control the gas recovery’ system 100. Examples of these devices are disclosed in further detail herein. Further, the hydraulic fluid is returned back to the hydraulic loop 118. Therefore, none of the hydraulic fluid is vented or wasted, but instead remains in a closed loop system.

[0019] FIG. 2 is a more detailed schematic diagram of the example gas recovery system 100 of FIG. 1. In the illustrated example, the gas recovery system 100 include a first filter 200 coupled to the first gas line 114. In some instances, the natural gas in the high pressure gas line 104 may carry contaminants (e.g., particulate or debris such as pipe scale, grit, sand, rust, etc., chemicals such as iron sulfide, etc.) that could cause damage or adverse effects to the downstream devices. Therefore, the first filter 200 is used to filter out and / or otherwise remove these contaminants before reaching the downstream devices (e.g., the valve 202, the first pump 110, etc.).

[0020] In the illustrated example, the gas recovery system 100 includes a valve 202 coupled to and / or otherwise incorporated into the first gas line 114, between the high pressure gas line 104 and the first pump 110. The valve 202 controls whether high pressure gas flows to the first pump 110. The valve 202 is operable between a closed state and an open state. When the valve 202 is closed, the valve 202 blocks or prevents the flow of gas to the first pump 110 and, thus, the first pump 110 is deactivated or off. When it is desired to utilize the gas recoverysystem 100 (e.g.. to transfer gas from the bleed gas source 108 to the low pressure gas line 106), the valve 202 can be opened. When the valve 202 is opened, the high pressure gas is allowed to flow through the first pump 110 to the low pressure gas line 106, thereby activating and / or otherwise driving the first pump 110. In some examples, the valve 202 is a hydraulically operated valve. For example, the valve 202 may be operated via hydraulic pressure from the hydraulic loop 118, as disclosed in further detail herein. The valve 202 is configured to automatically open when a certain amount of gas from the bleed gas source 108 has been collected.

[0021] In the illustrated example, the gas recovery system 100 includes a reservoir 204 in and / or fluidly coupled to the hydraulic loop 118. The reservoir 204 contains additional hydraulic fluid to ensure a sufficient amount of hydraulic fluid is available to be pumpedthrough the hydraulic loop 118. In the illustrated example, the reservoir 204 is fluidly coupled to the second hydraulic line 122 between the driving side of the second pump 112 and the driven side of the first pump 110.

[0022] In the illustrated example of FIG. 2, the gas recovery' system 100 includes a manual control valve 206, a first pressure relief valve 208, and a first bleed valve 210 fluidly coupled to the first hydraulic line 120, between the driven side of the first pump 110 and the driving side of the second pump 112. The manual control valve 206 can be used to manually (e.g., via a person) shut off the flow of hydraulic fluid through the hydraulic loop 118, such as during maintenance / repairs and / or an emergency shutdown. The first pressure relief valve 208 is used to vent or relieve excess pressure in the first hydraulic line 120 of the hydraulic loop 118. In the illustrated example, the first pressure relief valve 208 is fluidly coupled by a hydraulic return line 212 to the reservoir 204. If the pressure in the hydraulic loop 118 meets or exceeds a set or limit pressure, the first pressure relief valve 208 opens and routes hydraulic fluid back to the reservoir 204. This can be used to prevent or reduce an over-pressurization scenario. The first bleed valve 210 is used to vent or relieve pressure to the atmosphere should the hydraulic pressure become excessively high. The first bleed valve 210 may be configured to open at a higher limit pressure than the first pressure relief valve 208. This provides a failsafe to the system.

[0023] In the illustrated example, the gas recovery system 100 includes a second filter 214 and a second bleed valve 216 coupled to the second hydraulic line 122. The second filter 214 filters outs and / or otherwise removes contaminants in the hydraulic fluid in the hydraulic loop 118. The bleed valve 216 is similar to the first bleed valve 210 and is used to vent or relieve pressure in the second hydraulic line 122 should the pressure meet or exceed a high pressure limit.

[0024] In the illustrated example, the gas recovery system 100 includes an accumulator 218 fluidly coupled to the bleed gas source 108. The accumulator 218 receives and collects gas from the bleed gas source 108. For example, the accumulator 218 collects periodic puffs of gas from the gas-operated devices. The accumulator 218 is fluidly coupled by the first bleed line 124 to the driven side of the second pump 112. When a certain amount (e.g.. by pressure and / or volume) of gas is accumulated in the accumulator 218, the valve 202 is opened to activate the first and second pumps 110, 112 and begin pumping the gas from the accumulator 218 to the low pressure gas line 106. Therefore, the accumulator 218 is used to accumulate or gather a certain amount of gas before the pumping action occurs. This reduces the amount of time thefirst and second pumps 110, 1 12 are running and also ensures a sufficient amount of gas is present so as not to create vacuum on the bleed gas source 108.

[0025] In the illustrated example, the gas recover}7system 100 includes a pressure safety valve 220 fluidly coupled to the accumulator 218. The gas recovery system 100 includes a hydraulic pilot line 222 (also referred to as a sense line) to supply some of the hydraulic fluid from the hydraulic loop 118 to operate one or more devices. For example, as shown in FIG. 2. the hydraulic pilot line 222 is fluidly coupled to the pressure safety valve 220 and the valve 202. When the amount of gas in the accumulator 218 reaches a certain limit (e.g., a threshold weight, volume, pressure, etc.), the pressure safety valve 220 opens to allow hydraulic fluid to flow to the valve 202, which causes the valve 202 to open. The opening of the valve 202 starts and / or activates the first pump 110. which drives hydraulic fluid through the hydraulic loop 118, which drives or powers the second pump 1 12 to pump the bleed gas from the accumulator 218 to the low pressure gas line 106. In the illustrated example, the gas recovery system 100 includes a hydraulic return line 224 fluidly coupled between the pressure safety valve 220 and the reservoir 204. When the amount of gas in the accumulator 218 drops below the limit, the pressure safety valve 220 closes, and the hydraulic pressure in the hydraulic pilot line 222 between the pressure safety valve 220 and the valve 202 is vented back to the reservoir 204. In some examples, the valve 202 is spring biased to the closed position. Therefore, after the pressure safety valve 220 is closed, the valve 202 returns to the closed position, which deactivates the first and second pumps 110, 112. When the accumulator 218 gathers a sufficient amount of gas again, the valve 202 is again opened and the first and second pumps 110, 112 are activated. The process repeats continuously and autonomously. In other words, the gas recovery' system 100 can automatically start and stop using entirely pneumatic and hydraulic systems. Therefore, in some examples, no electronics devices (e.g.. electronic sensors, electronic switches, electronic controls, etc.) are needed on the gas recovery7system 100. This reduces the risk of an electrical spark around combustible gases.

[0026] In the illustrated example of FIG. 2, a pressure regulator 226 is coupled to the hydraulic pilot line 222 and used to reduce the hydraulic pressure from the first hydraulic line 120 down to a lower pressure for use by the devices. For example, while the pressure of the hydraulic fluid in the hydraulic loop 118 may be lOOOpsi, the pressure regulator 226 may reduce the pressure to lOOpsi for use in the hydraulic pilot line 222. In the illustrated example, the gas recovery system 100 includes a second pressure relief valve 228 coupled to the hydraulic pilot line 222. The second pressure relief valve 228 is fluidly coupled to the hydraulic return line 224. If the pressure in the hydraulic pilot line 222 exceeds a set or limit pressure, the secondpressure relief valve 228 opens to vent hydraulic pressure back the reservoir 204. which helps to prevent or reduce an over-pressurization scenario.

[0027] In the illustrated example, the gas recover} system 100 includes a check valve 230 coupled to the hydraulic pilot line 222 to ensure the flow of hydraulic fluid in one direction. The gas recovery system 100 also includes a pressure accumulator 232 (e.g., a bladder) fluidly coupled to the hydraulic pilot line 222. The pressure accumulator 232 contains a certain amount of hydraulic fluid to ensure a sufficient pressure is always present in the hydraulic pilot line 222 to operate the pressure safety valve 220 and the valve 202. Therefore, even if the first and second pump 110, 112 are not activated, a certain amount of hydraulic pressure exists in the hydraulic pilot line 222 so that the valve 202 can open.

[0028] In some examples, the gas recovery system 100 is packaged into a common housing or container. For example, the first pump 110, the second pump 112, the hydraulic loop 118, and the various devices may be packaged in a common housing. The housing may have one or more fluid connectors to connect the gas recovery' system 100 to the high and low pressure gas lines 104, 106 and the bleed gas source 108.

[0029] FIG. 3 is a schematic diagram of an example of the first pump 110. The first pump 110 is a gas-driven hydraulic pump. In this example, the first pump 110 is implemented as a ty pe of reciprocating piston pump.

[0030] In the illustrated example, the first pump 110 includes a driving cylinder 300 and first and second driven cylinders 302a, 302b. In the illustrated example, the first pump 110 includes a drive piston 306 in the driving cylinder 300 that divides the driving cylinder 300 into two chambers 308a, 308b. A switching valve 310 provides high pressure gas from the high pressure gas line 104 (FIGS. 1, 2) to the first and second chambers 308a, 308b in an alternating manner, which causes the drive piston 306 to move back-and-forth in the driving cylinder 300 in a reciprocating motion. The switching valve 310 vents the high pressure gas from the first and second chambers 308a, 308b to the low pressure gas line 106.

[0031] In the illustrated example, the first pump 110 includes a rod 312 coupled to and extending from the drive piston 306 in both directions. The rod 312 is coupled to a first piston 314a in the first driven cylinder 302a and a second piston 314b in the second driven cylinder 302b. As the drive piston 306 moves back-and-forth, the first and second pistons 314a, 314b are driven back-and-forth in their respective cylinders 302a, 302b. As shown in FIG. 3, the first and second hydraulic lines 120, 122 are fluidly coupled to both sides of the driven cylinders 302a, 302b via check valves 316 (one of which is referenced in FIG. 3). As the first and second pistons 314a, 314b move back-and-forth, hydraulic fluid is pumped from the first hydraulic line120 to the second hydraulic line 122 and, thus, hydraulic fluid is driven through the hydraulic loop 118 (FIGS. 1 and 2). Therefore, in this example, the first and second driven cylinders 302a, 302b are configured as double-acting reciprocating piston pumps. In other examples, the first and second driven cylinders 302a, 302b can be configured as single-acting reciprocating piston pumps. The driving cylinder 300 forms the driving portion of the first pump 110, and the first and second driven cylinders 302a, 302b form the driven side of the first pump 1 10.

[0032] The second pump 112 can also be configured as the same type of pump as show n in FIG. 3. However, the second pump 112 is a hydraulic-driven gas pump. Therefore, for the second pump 112, hydraulic fluid may be used to drive the drive piston 306, while the first and second driven cylinders 302a, 302b may be used as the driven portion that pumps the gas from the bleed gas source 108 to the low pressure gas line 106.

[0033] In other examples, the first and / or second pumps 112 can be implemented as other ty pes of pumps, such as single-acting reciprocating pumps, diaphragm pumps, bellows pumps, or plunger pumps.

[0034] In the example shown in FIGS. 1 and 2 the first pump 110 is driven by gas from the high pressure gas line 104. In other examples, the first pump 110 can be driven by another source, such as high pressure or compressed air. For example, many facilities have one or more lines of compressed air routed throughout the facility7for use by various equipment (e.g., valves). FIG. 4 shows an example of the gas recovery system 100 in which the first gas line 114 is connected to a compressed air line 400. As such, high pressure air can be used to drive the driving side of the first pump 110. Therefore, in this example, the first pump 110 is implemented as an air-driven hydraulic pump. The compressed air can be vented to the atmosphere or directed to another air line (e.g., a lower pressure air line).

[0035] While the bleed gas source 108 is described as representing one or more gas- operated devices, the bleed gas source 108 can also represent any source of gas that is desired to be collected and transferred into a gas line rather than venting into the atmosphere. For example, the gas source may be gas from a section of pipe or a vessel that needs to be evacuated prior to performing maintenance on the pipe or vessel.

[0036] "Including” and “comprising” (and all forms and tenses thereof) are used herein to be open ended terms. Thus, whenever a claim employs any form of “include” or “comprise” (e.g., comprises, includes, comprising, including, having, etc.) as a preamble or within a claim recitation of any kind, it is to be understood that additional elements, terms, etc., may be present without falling outside the scope of the corresponding claim or recitation. As used herein, when the phrase “at least” is used as the transition term in, for example, a preamble of a claim, it isopen-ended in the same manner as the term “comprising’" and “including"’ are open ended. The term “and / or” when used, for example, in a form such as A. B, and / or C refers to any combination or subset of A, B, C such as (1) A alone, (2) B alone, (3) C alone, (4) A with B, (5) A with C, (6) B with C, or (7) A with B and with C. As used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing structures, components, items, objects and / or things, the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. As used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A and B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B. Similarly, as used herein in the context of describing the performance or execution of processes, instructions, actions, activities, etc., the phrase “at least one of A or B” is intended to refer to implementations including any of (1) at least one A, (2) at least one B, or (3) at least one A and at least one B.

[0037] As used herein, singular references (e.g., “a”, “an”, “first”, “second”, etc.) do not exclude a plurality. The term “a” or “an” object, as used herein, refers to one or more of that object. The terms “a” (or “an”), “one or more”, and “at least one” are used interchangeably herein. Furthermore, although individually listed, a plurality of means, elements, or actions may be implemented by, e g., the same entity or object. Additionally, although individual features may be included in different examples or claims, these may possibly be combined, and the inclusion in different examples or claims does not imply that a combination of features is not feasible and / or advantageous.

[0038] As used herein, connection references (e.g., attached, coupled, connected, and joined) may include intermediate members between the elements referenced by the connection reference and / or relative movement between those elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and / or in fixed relation to each other. As used herein, stating that any part is in “contact” with another part is defined to mean that there is no intermediate part between the two parts.

[0039] Unless specifically stated otherwise, descriptors such as “first,” “second,” “third,” etc., are used herein without imputing or otherwise indicating any meaning of priority, physical order, arrangement in a list, and / or ordering in any way. but are merely used as labels and / or arbitrary names to distinguish elements for ease of understanding the disclosed examples. Insome examples, the descriptor “first' ’ may be used to refer to an element in the detailed description, while the same element may be referred to in a claim with a different descriptor such as “second” or “third.” In such instances, it should be understood that such descriptors are used merely for identifying those elements distinctly within the context of the discussion (e.g., within a claim) in which the elements might, for example, otherwise share a same name.

[0040] From the foregoing, it will be appreciated that example systems, methods, apparatus, and articles of manufacture have been disclosed that can be used to recovery gas from a gas source and re-inject the gas into a gas line rather than venting the gas to the atmosphere.

[0041] Examples and combinations of examples disclosed herein include the following:

[0042] Example 1 is a gas recovery system for use in a facility’ having a high pressure gas line and a low pressure gas line. The gas recovery’ system comprises a first pump to be fluidly coupled between the high pressure gas line and the low pressure gas line. The first pump is to be driven by a pressure differential between the high pressure gas line and the loyv pressure gas line. The gas recovery system includes a second pump to be fluidly coupled between a bleed gas source and the low pressure gas line. The second pump is to. when activated, transfer gas from the bleed gas source to the low pressure gas line. The gas recovery system also includes a hydraulic loop. The first pump is to, yvhen activated, drive hydraulic fluid through the hydraulic loop. The hydraulic fluid is to power the second pump.

[0043] Example 2 includes the gas recovery system of Example 1, further including a valve fluidly coupled between the high pressure gas line and the first pump, the valve operable between an open state in which high pressure gas is supplied to the first pump to activate the first pump and a closed state in yvhich gas floyv is blocked to the first pump to deactivate the first pump.

[0044] Example 3 includes the gas recovery system of Example 2, wherein the valve is a hydraulically operated valve.

[0045] Example 4 includes the gas recovery system of Examples 2 or 3, yvherein the valve is operated via hydraulic pressure from the hydraulic loop.

[0046] Example 5 includes the gas recovery system of any of Examples 2-5, further including an accumulator fluidly coupled to the bleed gas source and the second pump, the accumulator to collect an amount of gas from the bleed gas source.

[0047] Example 6 includes the gas recovery- system of Example 5, further including a pressure safety valve fluidly coupled to the accumulator.

[0048] Example 7 includes the gas recovery system of Example 6, further including a hydraulic pilot line between the hydraulic loop and the pressure safety valve, wherein, when apressure in the accumulator reaches a threshold pressure, the pressure safety valve opens to enable hydraulic pressure to the valve to open the valve.

[0049] Example 8 includes the gas recovery system of Example 7, wherein the hydraulic loop includes a reservoir.

[0050] Example 9 includes the gas recovery system of Example 8, further including a hydraulic return line between the pressure safety’ valve and the reservoir, wherein, when the pressure safety valve is closed, hydraulic pressure in the hydraulic pilot line is vented back to the reservoir.

[0051] Example 10 includes the gas recovery’ system of any of Examples 7-9, further including a pressure regulator coupled to the hydraulic pilot line.

[0052] Example 11 includes the gas recovery system of an of Examples 7-10, further including a pressure accumulator fluidly coupled to the hydraulic pilot line.

[0053] Example 12 is a gas recovery' system for use in a facility' having a high pressure gas line and a low pressure gas line. The gas recovery' system comprises a first pump having a driving side and a driven side, a first gas line fluidly coupling the high pressure gas line and the driving side of the first pump, a second gas line fluidly coupling the low pressure gas line and the driving side of the first pump, a second pump having a driving side and a driven side, a first bleed line fluidly coupling a bleed gas source and the driven side of the second pump, a second bleed line fluidly coupling the driven side of the second pump and the low pressure gas line, and a hydraulic loop fluidly coupling the driven side of the first pump and the driving side of the second pump.

[0054] Example 13 includes the gas recovery’ system of Example 12, further including a valve coupled to the first gas line, the valve operable between an open state in which high pressure gas is supplied to the first pump to activate the first pump and a closed state in which gas flow is blocked to the first pump to deactivate the first pump.

[0055] Example 14 includes the gas recovery system of Example 13, wherein the valve is hydraulically operated by hydraulic pressure from the hydraulic loop.

[0056] Example 15 includes the gas recovery system of any of Examples 12-14, further including a hydraulic pilot line to supply hydraulic fluid from the hydraulic loop to one or more devices to be used to operate the one or more devices.

[0057] Example 16 includes the gas recovery' system of any of Examples 12-1 , wherein the first pump includes a double-acting reciprocating piston pump.

[0058] Example 17 includes the gas recovery system of any of Examples 12-16, wherein the gas recovery system does not include any electronic devices.

[0059] Example 18 is a gas recovery system for use in a facility having a compressed air line and a gas line. The gas recovery system comprises a first pump to be fluidly coupled to a compressed air line. The first pump is to be driven by compressed air from the compressed air line. The gas recovery’ system includes a second pump to be fluidly coupled between a bleed gas source and the gas line. The second pump is to, when activated, transfer gas from the bleed gas source to the gas line. The gas recovery system also includes a hydraulic loop. The first pump is to, when activated, drive hydraulic fluid through the hydraulic loop. The hydraulic fluid is to power the second pump.

[0060] Example 19 includes the gas recovery7sy stem of Example 18, wherein the compressed air used by the first pump is vented to atmosphere.

[0061] Example 20 includes the gas recovery system of Examples 18 or 19, further including a hydraulic pilot line to supply hydraulic fluid from the hydraulic loop to one or more devices to be used to operate the one or more devices.

[0062] The following claims are hereby incorporated into this Detailed Description by this reference. Although certain example systems, methods, apparatus, and articles of manufacture have been disclosed herein, the scope of coverage of this patent is not limited thereto. On the contrary’, this patent covers all systems, methods, apparatus, and articles of manufacture fairly falling within the scope of the claims of this patent.

Claims

What Is Claimed Is:

1. A gas recovery system for use in a facility having a high pressure gas line and a low pressure gas line, the gas recovery system comprising: a first pump to be fluidly coupled between the high pressure gas line and the low pressure gas line, the first pump to be driven by a pressure differential between the high pressure gas line and the low pressure gas line; a second pump to be fluidly coupled between a bleed gas source and the low pressure gas line, the second pump to, when activated, transfer gas from the bleed gas source to the low pressure gas line; and a hydraulic loop, the first pump to, when activated, drive hydraulic fluid through the hydraulic loop, the hydraulic fluid to power the second pump.

2. The gas recovery system of claim 1 , further including a valve fluidly coupled between the high pressure gas line and the first pump, the valve operable between an open state in which high pressure gas is supplied to the first pump to activate the first pump and a closed state in which gas flow is blocked to the first pump to deactivate the first pump.

3. The gas recovery' system of claim 2, wherein the valve is a hydraulically operated valve.

4. The gas recovery' system of claim 2, wherein the valve is operated via hydraulic pressure from the hydraulic loop.

5. The gas recovery’ system of claim 2. further including an accumulator fluidly coupled to the bleed gas source and the second pump, the accumulator to collect an amount of gas from the bleed gas source.

6. The gas recovery’ system of claim 5. further including a pressure safety valve fluidly coupled to the accumulator.

7. The gas recovery' system of claim 6, further including a hydraulic pilot line between the hydraulic loop and the pressure safety valve, wherein, when a pressure in the accumulator reaches a threshold pressure, the pressure safety valve opens to enable hydraulic pressure to the valve to open the valve.

8. The gas recovery’ system of claim 7. wherein the hydraulic loop includes a reservoir.

9. The gas recovery' system of claim 8, further including a hydraulic return line between the pressure safety valve and the reservoir, wherein, when the pressure safety valve is closed, hydraulic pressure in the hydraulic pilot line is vented back to the reservoir.

10. The gas recovery system of claim 7, further including a pressure regulator coupled to the hydraulic pilot line.

11. The gas recovery system of claim 7, further including a pressure accumulator fluidly coupled to the hydraulic pilot line.

12. A gas recovery system for use in a facility having a high pressure gas line and a low pressure gas line, the gas recovery system comprising: a first pump having a driving side and a driven side; a first gas line fluidly coupling the high pressure gas line and the driving side of the first pump; a second gas line fluidly coupling the low pressure gas line and the driving side of the first pump; a second pump having a driving side and a driven side; a first bleed line fluidly coupling a bleed gas source and the driven side of the second pump; a second bleed line fluidly coupling the driven side of the second pump and the low pressure gas line; and a hydraulic loop fluidly coupling the driven side of the first pump and the driving side of the second pump.

13. The gas recovery system of claim 12, further including a valve coupled to the first gas line, the valve operable between an open state in which high pressure gas is supplied to the first pump to activate the first pump and a closed state in which gas flow is blocked to the first pump to deactivate the first pump.

14. The gas recovery system of claim 13, wherein the valve is hydraulically operated by hydraulic pressure from the hydraulic loop.

15. The gas recovery system of claim 12, further including a hydraulic pilot line to supply hydraulic fluid from the hydraulic loop to one or more devices to be used to operate the one or more devices.

16. The gas recovery system of claim 12, wherein the first pump includes a doubleacting reciprocating piston pump.

17. The gas recovery system of claim 12, wherein the gas recovery system does not include any electronic devices.

18. A gas recovery system for use in a facility having a compressed air line and a gas line, the gas recovery’ system comprising: a first pump to be fluidly coupled to a compressed air line, the first pump to be driven by compressed air from the compressed air line; a second pump to be fluidly coupled between a bleed gas source and the gas line, the second pump to, when activated, transfer gas from the bleed gas source to the gas line; and a hydraulic loop, the first pump to, when activated, drive hydraulic fluid through the hydraulic loop, the hydraulic fluid to power the second pump.

19. The gas recovery system of claim 18, wherein the compressed air used by the first pump is vented to atmosphere.

20. The gas recovery’ system of claim 18, further including a hydraulic pilot line to supply hydraulic fluid from the hydraulic loop to one or more devices to be used to operate the one or more devices.

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