Improved fluid sample pump system

Abstract

An improved fluid sample pump comprising an in-line pressure relief valve, an in-line synthetic lubricant oil supply associated with the air actuation port, a stainless steel actuator housing with a central air actuation input port and an internal anti-friction and anti-corrosion coating, an actuator piston with a polyurethane O-ring, and a shot peened galvanized music wire compression coil actuator piston return spring.

Description

[Technical Field]

[0001] This PCT international application claims priority to U.S. patent application Ser. No. 17 / 903,163, filed September 6, 2022.

[0002] The present invention relates to a pneumatic actuation fluid sample piston pump system assembly, particularly for use with natural gas liquids (NGLs) and cryogenic NGLs, and vaporized gases including these, that has improved performance through the use of a combination of elements including an in-line filter-regulator-lubricator (FRL) synthetic lubricant supply associated with a pressurized actuation gas / air input for lubricating the pump piston actuator, at least one in-line pressure relief valve for overpressure protection, a central air actuation port, an actuator piston with a polyurethane O-ring, a shot peened galvanized music wire compression coil actuator piston return spring, a stainless steel actuator housing, a friction and corrosion resistant coating, and a pressurized fluid throttle valve. [Background technology]

[0003] In the processing of natural gas samples, particularly NGL or cryogenic NGL, small liquid aliquots are extracted from the source and pumped under pressure to a sample collector. In such processes, it is important to maintain the fluid in a steady state, whether in vapor or liquid form, to prevent phase changes that can cause sampling irregularities. Therefore, it is desirable to minimize the presence of heat that can induce phase changes during the pumping process, especially for low-temperature processes such as -65°F (-54°C). Summary of the Invention [Problem to be solved by the invention]

[0004] The objective of the improved fluid sample removal pump of the present invention is to significantly reduce, if not completely eliminate, heat generation by the pump while improving operational reliability.

[0005] Another object of the present invention is to provide a combination of features that reduces the need for pumping interruptions due to part replacement.

[0006] A further object of the present invention is to maximize the duty cycle and operating life of the field while minimizing the maintenance and replacement of moving parts and / or the entire pump assembly.

[0007] It is yet another object of the present invention to provide a pneumatically operated sample pump operable to allow continuous, uninterrupted, metered sample extraction from large sources (tanker ships, railroad tank cars, pipelines, etc.).

[0008] It is yet another object of the present invention to eliminate the need for a pneumatic input calibrator by relying on the process control timing of an associated programmable logic controller (PLC) to acquire a standard fixed sample volume (e.g., 3 cc per stroke).

[0009] While exemplary, non-limiting embodiments of the present invention may overcome the aforementioned and other drawbacks associated with prior art liquid vaporization and measurement systems, the present invention does not necessarily have to overcome the aforementioned drawbacks, and exemplary, non-limiting embodiments of the present invention may not overcome any of the aforementioned problems. [Means for solving the problem]

[0010] To achieve these and other objects, embodiments of the present invention provide an improved pneumatically operated piston fluid sample pump operable over a temperature range compatible with an operating environment for sampling natural gas liquids (NGLs) and cryogenic NGLs in either vapor or liquid phases, the pump having a pressurized working gas, a pressurized working gas inlet port, a sample take-off input, and a pressurized fluid sample output, the pump including: an in-line oil supply device for introducing synthetic lubricating oil into the pressurized working gas in a controlled dropwise manner; an in-line pressure relief valve disposed downstream of the in-line oil supply device; a stainless steel piston actuator housing including an upper wall with a central inlet port for the pressurized working gas, an internal piston head chamber of a first selected diameter having an inner surface with a non-reactive corrosion-resistant, anti-friction coating, and a lower wall; a piston head having a diameter corresponding to the first selected diameter for reciprocating movement within the piston head chamber; a connecting piston rod; and a piston head assembly having a diameter corresponding to the first selected diameter for reciprocating movement within the piston head chamber. a shot peened, zinc plated, music wire coil piston return compression spring mounted and seated within the piston head chamber between the piston head and the bottom wall; an elongated stainless steel piston plunger cylinder housing secured to and projecting from the bottom wall of the stainless steel piston actuator housing, the stainless steel piston plunger cylinder housing having an inner surface with a non-reactive corrosion and friction resistant coating corresponding to the second selected diameter; a plurality of polyurethane O-rings spaced apart on the piston plunger corresponding to the second selected diameter; a fluid sample input to the stainless steel piston plunger cylinder housing; a pressurized fluid sample output; and a throttle valve with an integral bypass disposed in series with the pressurized fluid sample output.

[0011] The present invention provides a further embodiment of the above-described embodiment, characterized in that a filter regulator lubricator (FRL) is used when the compressed working air needs to be oiled as well as cleaned. The filter regulator removes condensate and coarse debris from the compressor. The lubricator periodically supplies a precise dose of lubricating oil to the working air before it enters the inner surface of the pump housing to minimize frictional heat generation due to the reciprocating piston motion. The lubricating oil has a low viscosity that is substantially stable over a temperature range.

[0012] The present invention provides a further embodiment of the foregoing embodiment, characterized in that the air pressure input is centrally located to promote uniform pressurization of the actuation piston head and reduce uneven torque forces on the piston due to an off-center air input. The present invention also eliminates the need for a pressure relief burst disk integrated into the actuator housing. Elimination of the burst disk eliminates the need to disassemble the pump to replace a burst disk due to overpressurization, thereby reducing the downtime and labor required for such repairs.

[0013] The present invention provides a further embodiment of the previous embodiment, characterized in that the in-line fuelling device is controlled by a PLC.

[0014] The invention provides a further embodiment of any of the preceding embodiments, wherein the in-line fueling system includes a filter and a pressure regulator.

[0015] The present invention provides further embodiments of any of the foregoing embodiments, further characterized by a sample collection cylinder connected to a pressurized fluid sample output, and a pressure relief valve to prevent over-pressurization of the sample collection cylinder.

[0016] A further object of the present invention is achieved by a system facilitating improved continuous and uninterrupted operation of a pneumatically actuated fluid sample pump assembly using a combination of an air input line pressure relief valve, an air input in-line synthetic oil lubrication device, a central air input to the pump piston head chamber including a friction and corrosion resistant coating, a reciprocating piston plunger cylinder incorporating polyurethane sealing O-rings to reduce thermal stresses due to heat generation during operation, a stainless steel actuator housing and piston plunger cylinder housing for heat dissipation, a shot peened zinc plated music wire piston return spring, and an in-line throttle valve associated with the pressurized fluid output.

[0017] The present invention provides a further embodiment of the previous embodiment, characterized in that the piston plunger cylinder includes two spaced apart polyurethane sealing O-rings.

[0018] The present invention provides a further embodiment of any of the preceding embodiments, wherein the in-line oiling device is controlled by a PLC to periodically introduce synthetic lubricant into instrument air introduced into the pump piston head chamber or housing through an air pressure input port.

[0019] a piston-plunger chamber, a sample inlet, and a pressurized sample outlet; compressing the piston head against the piston-head return spring to pressurize a metered quantity of sample fluid introduced through the sample inlet by the piston-plunger; passing the pressurized sample fluid through the pressurized sample outlet; passing the pressurized sample fluid through a sample collection cylinder; and exhausting the flow through the input / output feedthrough to depressurize the piston head and piston-head return spring and draw a metered quantity of sample fluid from the sample inlet into the piston-plunger chamber.

[0020] The present invention provides a further embodiment of the aforementioned method embodiment, wherein the method further comprises the step of providing a PLC controller to control the periodic injection of liquid lubricant and the periodic passing of the metered flow through the pneumatically actuated pump.

[0021] The present invention provides a further embodiment of either of the two preceding method embodiments, wherein a pressurized sample bypass is disposed between the pressurized sample outlet and the sample collection cylinder, and the method further comprises the step of preventing over-pressurization of the sample collection cylinder by redirecting the pressurized sample into the pressurized sample bypass. [Brief explanation of the drawings]

[0022] Aspects of the present invention will become more readily apparent from the detailed description of illustrative, non-limiting embodiments thereof, taken in conjunction with the accompanying drawings.

[0023] [Figure 1] FIG. 1 is a schematic diagram of an embodiment of a pneumatically actuated fluid sample pump system according to the present invention. [Figure 2] FIG. 2 is a schematic diagram of the fluid sample pump of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] Exemplary, non-limiting embodiments of the present invention are described in detail below. While specific configurations and dimensions are described to provide a clear understanding, it should be understood that the disclosed dimensions and configurations are provided for illustrative purposes only. Those skilled in the art will understand that other dimensions and configurations can be used without departing from the spirit and scope of the present invention, unless otherwise specified.

[0025] As used herein, "substantially," "relatively," "nearly," "about," and "approximately" are relative modifiers intended to indicate acceptable variations from the property so modified. They are not limited to the absolute value or property they modify, but rather, they are close to or approximate such physical or functional property.

[0026] In the detailed description, references to "one embodiment," "one embodiment," or "in an embodiment" mean that the referenced feature is included in at least one embodiment of the invention. Furthermore, separate references to "one embodiment," "one embodiment," or "in an embodiment" do not necessarily refer to the same embodiment, but such embodiments are not mutually exclusive unless stated to be mutually exclusive, except as would be readily apparent to one of ordinary skill in the art. Thus, the present invention may include any various combinations and / or integrations of the embodiments described herein.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" are intended to encompass the plural forms as well, unless the context clearly indicates otherwise. Furthermore, as used herein, the base terms "comprise" and / or "have" specify the presence of stated features, integers, steps, operations, elements, and / or components, but are understood not to exclude the presence or addition of at least one other feature, integer, step, operation, element, component, and / or group thereof.

[0028] As used herein, the terms "features," "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus characterized by a set of features is not necessarily limited to only those features but may include other features not expressly recited or inherent to such process, method, article, or apparatus.

[0029] It should also be understood that, as used herein, reference to a range of values ​​is intended to encompass all values ​​within that range, including the endpoints of the range, unless specifically stated to the contrary.

[0030] As used herein, "connected" includes a physical connection, permanently fixed or adjustable attachment, whether direct or indirect. Thus, unless specified otherwise, "connected" is intended to encompass any operatively functioning connection.

[0031] In the following description, reference is made to the accompanying drawings, which are provided for purposes of illustration as representative of specific exemplary embodiments in which the invention may be practiced. The illustrated embodiments below are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other embodiments may be utilized and structural changes may be made based on presently known structural and / or functional equivalents without departing from the scope of the invention.

[0032] It will be apparent to those skilled in the art, upon consideration of the following detailed description, that the invention herein provides a novel liquid vaporization apparatus and method for providing enhanced efficiency while mitigating problems of the prior art.

[0033] The present invention involves an improvement over the current Mustang liquid sample pump. The improved sample pump is applicable to sample collection during fluid transport operations (either gas or liquid phase) and is particularly suited for continuous operation and use in a variety of harsh ambient environments, and therefore for cryogenic liquid sample collection. In the following description, the actuation elements of the pneumatic pump are first described, followed by the sample pressurization elements.

[0034] Assembly 10 includes a cabinet-style housing 12 incorporating a suitable power supply 14 for an associated programmable logic controller (PLC) 16. A feedthrough in cabinet 12 provides a pressurized operational instrument air / gas inlet line 22, which delivers pressurized instrument air to and through an in-line filter / regulator / lubricator (FRL) unit 24. The FRL unit filters the pressurized instrument air, regulates its flow and pressure, and injects a synthetic lubricant into the instrument air stream. An oiling system is automatically controlled to periodically inject droplets of synthetic oil into the instrument air stream prior to introducing the pressurized air into the downstream piston chamber, ensuring the presence of lubricant in the piston chamber during pump operation.

[0035] Filter / regulator / lubricator (FRL) units are well-known devices, as described in U.S. Patent Nos. 3,945,465 and 7,637,977. One example of an FRL suitable for use in connection with the illustrated embodiment is the Wilkerson Model C18-03-FLG0B, available from Grainger. In this embodiment, the FRL unit 24 injects a thermally stable, non-reactive, low-viscosity lubricant to prevent wear damage, limit heat generation, avoid sample fluid partitioning / phase change and resulting compositional anomalies as it passes through the pump during operation, and protect and lubricate the piston pump plunger O-rings described below by filling any surface irregularities that may occur during operation. The injecting lubricant maintains a smooth surface with minimal friction, preventing damage from abrasion, pinching, or shearing, and promoting proper seating of the O-ring on the piston. One such lubricant is a non-hardening silicone called Super Lube® O-Ring Silicone Lubricant, sold by Synco Chemical Company of Bohemia, New York. The use of this lubricant improves the stable operational performance of pumps in the temperature range from ambient to as low as -65°F (-54°C) associated with natural gas liquids (NGL) or cryogenic NGL fluids and processes (whether in liquid or vapor form).

[0036] After passing through the FRL, the air flow passes through an in-line pressure relief valve 26 and a three-way solenoid valve 28 controlled by the PLC 16 to provide an outlet for the overpressurized air before being introduced into the input / output 20. The solenoid valve 28 is connected to an instrument air relief bypass line 30 which provides a vent for the air output from the pump 18.

[0037] The fluid sample pressurization assembly includes a fluid sample input line 32 containing a shut-off valve 31, which feeds a pump 18. As shown in detail in FIG. 2 , the pump 18 includes an internally protectively coated stainless steel actuator housing 34 and an internally protectively coated cylindrical piston-plunger chamber 36, which are secured to a pump sample outlet and bypass manifold 38. The actuator housing 34 includes an actuation air input / output section 20 centrally located in its upper wall, a reciprocating piston head 40, a piston return spring 42, and a lower cylindrical piston reciprocating channel dimensionally matching an actuation piston body 46. The piston head 40 is rigidly secured to the piston-plunger body 46 via a connecting rod 49, which includes a plurality of axially spaced O-rings 48 that provide improved wear resistance and a wide thermal operating range, even at temperatures as low as −65° F. (−54° C.). The O-rings are located on the outer circumferential surface to seal against fluid leakage.

[0038] To improve the duty cycle life of the piston actuator and actuator spring, the interior surfaces of the actuator housing and cylindrical piston reciprocating channel include a coating that resists oxidation, corrosion, and friction. One such coating is a low surface energy Dursan® coating, proprietary to SilcoTek Corporation of Bellefonte, Pennsylvania, which is vapor-deposited and bonded to the internal wear surfaces of moving piston pump components to reduce the generation of heat energy during repeated reciprocating motion of the piston and O-ring within the housing and cyclic compression / decompression of the actuator spring.

[0039] The piston return spring 42 is constructed from high-carbon steel music wire, which has higher tensile strength than stainless steel and the ability to operate effectively over a wider temperature range, even at temperatures as high as 250°F (121°C). The music wire is also shot-peened to improve cycle life and reduce the need for replacement. The shot-peening process deforms the surface of the music wire by bombarding it with small beads / shots, thereby improving the strength of the hardened spring and relieving residual stresses on the surface. After shot-peening, the music wire spring is galvanized to give the music wire a bright, reflective finish, improving corrosion resistance and reducing heat generation. The dimensions and compressed length of the shot-peened, galvanized music wire remain essentially unchanged compared to conventional springs, and the number of compressions required before replacement due to spring fatigue / failure is significantly increased, improving continued operation. In one test, the compression spring was cycled in a laboratory at room temperature (80°F / 26°C) for 420 hours, for a total of four weeks. Testing was conducted nonstop (Monday morning to Friday afternoon) without any spring failure, resulting in the equivalent of 189,000 sampling runs of 3cc / ml samples.

[0040] Considering now the flow of a fluid sample through the pump assembly, fluid enters the pump from input line 32 via pump inlet 50 and then into pump chamber 36. This occurs when, under the timing control of PLC 16, actuation air pressure in actuator housing 34 is released, opening solenoid valve 28 and allowing fluid to flow back through single input / output 20 and out air relief line 30, decompressing spring 42. During the next pressurization cycle, pressurized instrument air is introduced through central input / output 20, exerting uniform pressure across piston head 40 and forcing piston body 46 to move within the cylindrical piston reciprocating channel, pressurizing the sample fluid. The pressurized sample fluid then exits the chamber through pressurized fluid sample loop 52 and enters pump outlet / bypass manifold 38, which includes a manual three-way valve 54 that redirects flow from pressurized fluid outlet 56 to bypass outlet 58 during system startup or repair.

[0041] Similarly, a manually actuated two-way shut-off valve 58 is located in-line downstream of the pressurized fluid outlet 56 to terminate the flow of pressurized fluid from the outlet to a further manual three-way valve 60. During normal sample collection, the valve 60 directs the flow of pressurized fluid to a sample collection cylinder 62. When disconnection of the collection cylinder 62 is desired (if full, during start-up, or if an overpressure condition is detected), the valve 60 rotates to divert the pressurized fluid sample through a bypass 62 to a line 64 connected to the bypass outlet 58. A further manually actuated two-way valve is located in series between the junction of the pump bypass outlet 58 and the bypass 62 to selectively isolate the respective lines. Located downstream of the bypass 62 is a valved bypass port 68 for venting pressurized gas in the bypass arrangement from the cabinet 12.

[0042] While a single embodiment of the invention has been described in the foregoing specification, it will be appreciated that many modifications and embodiments of the invention pertaining to this invention will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing description and the associated drawings. Accordingly, the invention is not limited to the specific embodiments disclosed herein, and many modifications and other embodiments of the invention are intended to be included within the scope of the invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. [Industrial Applicability]

[0043] The present invention is useful in providing an improved fluid sample pump that is particularly useful for sampling natural gas liquids by providing a pneumatically actuated sample pump that is operable to reduce the need for pump downtime due to part replacement, maximize the duty cycle and operating life of the field, minimize maintenance and replacement of moving parts and / or the entire pump assembly, and enable continuous, uninterrupted, metered sample extraction from large sources by relying on a combination of an in-line pressure relief valve, an in-line synthetic lubricant oil supply associated with the air actuation port, a stainless steel actuator housing with a central air actuation input port and an internal anti-friction and anti-corrosion coating, an actuator piston with a polyurethane O-ring, and a shot peened, zinc-plated music wire compression coil actuator piston return spring.

Claims

1. 1. An improved pneumatically operated piston fluid sample pump operable over a temperature range compatible with the operating environment for sampling natural gas liquids (NGL) and cryogenic NGL in either vapor or liquid phase, the pump having a pressurized working gas, a pressurized working gas inlet port, a sample withdrawal input, and a pressurized fluid sample output, the pump comprising: an in-line oil supply system for introducing a synthetic lubricating oil into the pressurized working gas in a controlled dropwise manner; an in-line pressure relief valve associated with the pressurized actuation inlet port and positioned downstream of the in-line fueling device; a stainless steel piston actuator housing including: an upper wall with a central inlet port for said pressurized working gas; an internal piston head chamber of a first selected diameter having an inner surface with a non-reactive corrosion-resistant and friction-reducing coating; and a lower wall; an actuating piston including a piston head having a diameter corresponding to the first selected diameter for reciprocating movement within the piston head chamber, a connecting piston rod, and a piston plunger cylinder of a second selected diameter connected to the piston rod; a shot peened, zinc plated, music wire coil piston return compression spring mounted within the piston head chamber between the piston head and the bottom wall; an elongated stainless steel piston plunger cylinder housing secured to and projecting from a bottom wall of the stainless steel piston actuator housing, the stainless steel piston plunger cylinder housing having an inner surface with a non-reactive corrosion-resistant and friction-reducing coating corresponding to the second selected diameter; a plurality of polyurethane O-rings spaced apart on the piston plunger corresponding to the second selected diameter; a fluid sample input to the stainless steel piston plunger cylinder housing; a pressurized fluid sample output; an improved pneumatically operated piston fluid sample pump, characterized by a throttle valve with an integral bypass disposed in series with said pressurized fluid sample output.

2. 10. The improved pneumatically operated piston fluid sample pump of claim 1, wherein said in-line oiling device is controlled by a PLC.

3. 10. The improved pneumatically operated piston fluid sample pump of claim 1, wherein said in-line oiling system includes a filter and a pressure regulator.

4. 10. The improved pneumatically operated piston fluid sample pump of claim 1 further characterized by a sample collection cylinder connected to said pressurized fluid sample output, and a pressure relief valve to prevent overpressurization of said sample collection cylinder.

5. 1. A system for facilitating improved continuous and uninterrupted operation of a pneumatically actuated fluid metering sample pump assembly, comprising: Air input line pressure relief valve, air input in-line oil supply device, a stainless steel actuator housing; a central air input to the pump piston head chamber having a friction and corrosion resistant coating; Shot-peened zinc-plated music wire piston head return spring; a piston plunger cylinder housing disposed below the actuator housing and having dimensions corresponding to the piston plunger cylinder for cyclic reciprocating movement therein, the piston plunger cylinder housing having a plurality of polyurethane sealing O-rings assembled thereto; The system is characterized by the combination of an in-line throttle valve associated with the pressurized fluid output.

6. 6. The improved sample pump of claim 5, wherein said piston plunger cylinder includes two spaced apart polyurethane sealing O-rings.

7. 6. The improved sample pump of claim 5, wherein the in-line oiling device is controlled by a PLC to periodically introduce synthetic lubricant into instrument air introduced into the pump piston head chamber or the housing through an air pressure input port.

8. 1. A collection method for providing a metered volume of a pressurized fluid sample, comprising: providing a flow of pressurized working air from a source; periodically injecting a liquid lubricant into said flow; passing the flow through a pressure relief valve to prevent overpressure; periodically passing said metered flow through a central input / output feedthrough to a pneumatically actuated pump housing, said pneumatically actuated pump housing including an anti-friction coating, a piston including a piston head, a shot peened zinc plated music wire compression piston head return spring, a piston plunger, a piston plunger chamber, a sample inlet and a pressurized sample outlet; compressing the piston head against the piston head return spring to pressurize a metered amount of sample fluid introduced through the sample inlet by the piston plunger; passing the pressurized sample fluid through the pressurized sample outlet; passing the pressurized sample fluid through a sample collection cylinder; and expelling the flow through the input / output feedthrough to depressurize the piston head and the piston head return spring, drawing a metered amount of sample fluid from the sample inlet into the piston plunger chamber.

9. 9. The method of claim 8, further comprising the step of providing a PLC controller to control the periodic injection of liquid lubricant and the periodic passing of said metered flow through said pneumatically operated pump.

10. 9. The method of claim 8, wherein a pressurized sample bypass is disposed between the pressurized sample outlet and the sample collection cylinder, the method further comprising the step of preventing overpressurization of the sample collection cylinder by redirecting pressurized sample into the pressurized sample bypass.

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