[0001] This application claims priority to U .S. Utility Patent Application having Serial No. 1 4/202,033, which was filed March 10, 2014 and U.S. Provisional Patent Application having Serial No. 61 /781 ,383, which was filed March 1 4, 2013. These priority applications are hereby incorporated by reference in their entirety into the present application to the extent consistent with the present application.

Background

[0002] Hydrocarbons, including liquefied natural gas (LNG) and ethylene, may be used in a refinery, or other petrochemical setting, as an energy source or source material for various processes. Typically, one or more compressors may be used in the processing of such hydrocarbons. In particular, the propane and propylene compressors utilized for the processing of LNG and ethylene, respectively, are typically beam-style, multi-stage centrifugal compressors.

[0003] Generally, a beam-style, multi-stage centrifugal compressor includes a casing and a plurality of stages disposed therein, each stage including an inlet guide, an impeller, a diffuser, and a return channel that collectively raise the pressure of the gas orworking fluid. A main inlet of the beam-style, multi-stage centrifugal compressor receives the gas flow from an inlet pipe coupled to the main inlet, distributes the flow around the circumference of the casing, and injects the flow into the first inlet guide disposed immediately upstream of the impeller of the first stage. The gas is drawn into the impeller from the first inlet guide and driven (or propelled) to a tip of the impeller, thereby increasing the velocity of the gas. The centrifugal compressor may also include a diaphragm assembly including all of the various components contained within the back half or downstream end of the compressor stage. The diaphragm assembly may form at least in part the gas flow path of the centrifugal compressor.

[0004] The diaphragm assembly may include a diffuser proximate the tip of the impeller and in fluid communication therewith. The diffuser is configured to convert the velocity of the gas received from the impeller to potential energy in the form of increased static pressure, thereby resulting in the compression of the gas. The diaphragm assembly further includes a return channel in fluid communication with the diffuser and configured to receive the compressed gas from the diffuser and inject the compressed gas into a succeeding compressor stage. Otherwise, the compressed gas is ejected from the gas flow path via a discharge volute or collector that gathers the flow from the final stage and sends it down the discharge pipe.

[0005] Applications, such as propane refrigeration or propylene units for LNG and ethylene, respectively, generally require one or more flow streams, generally referred to as sidestream flows, to be introduced into the centrifugal compressor at respective flow inlets other than the main inlet. These sidestream flows may be introduced through additional flanges added to or formed in the casing. The additional inlets required for the sidestream flow typically necessitate corresponding components including, for example, sidestream inlet plenums and sidestream scoop vanes, to mix the sidestream flow with the working fluid in the centrifugal compressor.

[0006] The mixing of the sidestream flow and the working fluid typically occurs in the inlet guide of the respective stage, immediately upstream of the impeller. Improper or insufficient mixing can lead to pressure and temperature stratification (i.e., non-uniform pressure and temperature fields). Such skewed pressure and temperature fields degrade the performance of the downstream stage, causing the operating pressures to fall short of the process requirements. Moreover, it is often desirable to have the ability to adjust the performance of the compressor to match the process requirements via movable geometry (such as movable inlet guide vanes or movable diffuser vanes). Generally, it is much more challenging to install movable geometry in a beam-style compressor because of the limited space in which to install the drive mechanisms and linkages.

[0007] What is needed, then, is an efficient system including a compressor configured to provide for a working fluid and sidestream flow mix having a substantially uniform temperature and pressure field, and further configured to allow for the facile installation of movable geometry to provide for the tuning of the compressor for varying process requirements. Summary

[0008] Embodiments of the disclosure may provide a system for mixing and pressurizing a plurality of process fluid streams. The system includes at least one driver including a drive shaft, the driver configured to provide the drive shaft with rotational energy. The system may also include at least one compressor including a rotary shaft, the rotary shaft being operatively coupled to the drive shaft and configured such that the rotational energy from the drive shaft is transmitted to the rotary shaft. The system may further include a first junction formed from a first plurality of conduits. The plurality of conduits may include a first conduit fluidly coupled to the at least one compressor, the first conduit forming a first conduit diameter and configured to flow therethrough a first process fluid stream of the plurality of process fluid streams. The plurality of conduits may also include a second conduit fluidly coupled to the first conduit and the at least one compressor, the second conduit configured to flow therethrough a second process fluid stream of the plurality of process fluid streams. The first junction may be disposed a first distance at least three times the first conduit diameter upstream of the at least one compressor, such that the first process fluid stream and the second process fluid stream are mixed and form a first combined process fluid stream prior to being fed into and pressurized in the at least one compressor.

[0009] Embodiments of the disclosure may further provide a method for mixing and pressurizing a plurality of process fluid streams. The method includes driving a rotary shaft of at least one compressor via a first drive shaft operatively coupled to the rotary shaft, the first drive shaft driven by a first driver. The method may also include feeding a first process fluid stream of the plurality of process fluid streams through a first conduit having a first conduit diameter and fluidly coupled to the at least one compressor. The method may further include feeding a second process fluid stream of the plurality of process fluid streams through a second conduit coupled to the first conduit at a first junction disposed upstream of the at least one compressor a first distance of at least three times the first conduit diameter. The method may also include mixing the first process fluid stream and the second process fluid stream at the first junction, thereby forming a first combined process fluid stream. The method may further include feeding the first combined process fluid stream into the at least one compressor, and pressurizing the first combined process fluid stream in the at least one compressor. [0010] Embodiments of the disclosure may further provide a system for removing at least a portion of a process fluid stream. The system may include at least one driver including a drive shaft, the driver configured to provide the drive shaft with rotational energy. The system may also include at least one compressor including a rotary shaft, the rotary shaft being operatively coupled to the drive shaft and configured such that the rotational energy from the drive shaft is transmitted to the rotary shaft. The system may further include a first junction formed from a first plurality of conduits. The first plurality of conduits may include a first conduit fluidly coupled to the at least one compressor, the first conduit forming a first conduit diameter and configured to flow therethrough the process fluid stream. The first plurality of conduits may also include a second conduit fluidly coupled to the first conduit and an external component, the second conduit configured to flow therethrough the at least a portion of the process fluid stream. The first junction may be disposed a first distance at least three times the diameter of the first conduit upstream of the at least one compressor, such that the at least a portion of the process fluid stream is removed from the process fluid stream and fed to the external component via the second conduit.

[0011] Embodiments of the disclosure may further provide a method for removing at least a portion of a process fluid stream. The method may include driving a rotary shaft of at least one compressor via a drive shaft operatively coupled to the rotary shaft, the drive shaft driven by a driver. The method may also include feeding the process fluid stream through a first conduit having a first conduit diameter and being fluidly coupled to the at least one compressor. The method may further include feeding the at least a portion of a process fluid stream through a second conduit coupled to the first conduit at a first junction disposed upstream of the at least one compressor a distance of at least three times the first conduit diameter, thereby removing the at least a portion of a process fluid stream from the process fluid stream.

Brief Description of the Drawings

[0012] The present disclosure is best understood from the following detailed description when read with the accompanying Figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

[0013] Figure 1 illustrates a schematic diagram of a system for mixing and pressurizing a plurality of process fluid streams, the system including a plurality of compressors and a plurality of drivers, according to one or more embodiments.

[0014] Figure 2 illustrates a schematic diagram of another system for mixing and pressurizing a plurality of process fluid streams, the system including a plurality of compressors operatively coupled to a driver via a plurality of gears, according to one or more embodiments.

[0015] Figure 3 illustrates a schematic diagram of a system for removing at least a portion of a process fluid, the system including a plurality of compressors and a plurality of drivers, wherein at least one sidestream may provide process fluid to an external process component, according to one or more embodiments.

[0016] Figure 4 illustrates a schematic diagram of another system for removing at least a portion of a process fluid, the system including a plurality of compressors operatively coupled to a driver via a plurality of gears, wherein at least one sidestream may provide process fluid to an external process component, according to one or more embodiments.

[0017] Figure 5 illustrates a flowchart of an exemplary method for mixing and pressurizing a plurality of process fluid streams, according to one or more embodiments.

[0018] Figure 6 illustrates a flowchart of an exemplary method for removing at least a portion of a process fluid stream, according to one or more embodiments.

Detailed Description

[0019] It is to be understood that the following disclosure describes several exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described below to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. Additionally, the present disclosure may repeat reference numerals and/or letters in the various exemplary embodiments and across the Figures provided herein. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various exemplary embodiments and/or configurations discussed in the various Figures. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Finally, the exemplary embodiments presented below may be combined in any combination of ways, i.e., any element from one exemplary embodiment may be used in any other exemplary embodiment, without departing from the scope of the disclosure.

[0020] Additionally, certain terms are used throughout the following description and claims to refer to particular components. As one skilled in the art will appreciate, various entities may refer to the same component by different names, and as such, the naming convention for the elements described herein is not intended to limit the scope of the invention, unless otherwise specifically defined herein. Further, the naming convention used herein is not intended to distinguish between components that differ in name but not function. Additionally, in the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to." All numerical values in this disclosure may be exact or approximate values unless otherwise specifically stated. Accordingly, various embodiments of the disclosure may deviate from the numbers, values, and ranges disclosed herein without departing from the intended scope. Furthermore, as it is used in the claims or specification, the term "or" is intended to encompass both exclusive and inclusive cases, i.e. , "A or B" is intended to be synonymous with "at least one of A and B," unless otherwise expressly specified herein.

[0021] Figures 1 and 2 illustrate exemplary embodiments of a sidestream mixing system 1 00, 200 configured to efficiently and effectively mix and compress process fluid streams having differing temperatures, pressures, volumetric and/or mass flow rates. The sidestream mixing system 1 00,200 may be further configured to mix and compress process fluid streams fed into the sidestream mixing system 1 00, 200 via a plurality of sidestreams. In other exemplary embodiments shown in Figures 3 and 4, a sidestream mixing system 300, 400 may be configured to efficiently mix and remove at least a portion of a process fluid stream. The process fluid may include, for example, hydrocarbons, including LNG and ethylene; however, those of ordinary skill in the art will appreciate that the sidestream mixing system may process non-hydrocarbon-based process fluids, such as ammonia.

[0022] The sidestream mixing system 100, 200 may include one or more drivers 102, each driver 1 02 having a drive shaft 1 04 and configured to provide the drive shaft 104 with rotational energy. In the exemplary embodiment illustrated in Figure 1 , the sidestream mixing system 100 includes a plurality of drivers 1 02. In another exemplary embodiment illustrated in Figure 2, the sidestream mixing system 200 includes a single driver 1 02. The driver 1 02 may be an electric motor, such as a permanent magnet motor having permanent magnets installed on a rotor portion (not shown) and further having a stator portion (not shown). As will be appreciated, other embodiments may employ other types of electric motors, such as, but not limited to, synchronous, induction, brushed DC motors, etc. Further, the driver 1 02 may be a hydraulic motor, an internal combustion engine, a gas turbine, or any other device capable of rotatably driving the drive shaft 104, either directly or through a power train. As shown in Figure 1 , the sidestream mixing system 1 00 may include a first driver 106 and a second driver 1 08; however, one of ordinary skill in the art will appreciate that the number of drivers 102 in the sidestream mixing system 1 00, 200 may vary based on numerous conditions, such as, for example, the type of compressor employed or the number of sidestreams fed into the sidestream mixing system.

[0023] As shown in Figure 1 , each driver 1 02 may be operatively coupled to a plurality of compressors 1 1 0. In an exemplary embodiment, the drive shaft 104 of each driver 102 may be integral with or coupled to a rotary shaft 1 1 2 of a respective compressor 1 10 at each end of the drive shaft 1 04 in a "double-ended" configuration. In such a configuration, each driver 1 02 drives a respective drive shaft 1 04, which in turn drives the rotary shafts 1 1 2 of the respective coupled compressors 1 1 0. In an exemplary embodiment, each driver 1 02 is coupled to two compressors 1 10. As shown in Figure 1 , the drive shaft 104 of the first driver 106 may have a first end 1 1 4 and a second end 1 1 6, such that the first end 1 14 is coupled to the rotary shaft 1 12 of a first compressor 1 18 and the second end 1 16 is coupled to the rotary shaft 1 1 2 of a second compressor 1 20. Likewise, the second driver 1 08 may have a first end 1 22 and a second end 1 24, such that the first end 1 22 is coupled to the rotary shaft 1 1 2 of a third compressor 126 and the second end 124 is coupled to the rotary shaft 1 1 2 of a fourth compressor 1 28. [0024] In the exemplary embodiment of the sidestream mixing system 200 of Figure 2, the drive shaft 104 of the driver 102 is coupled to a plurality of gears 1 30 configured to transmit the rotational energy of the drive shaft 1 04 to the rotary shafts 1 1 2 of the respective compressors 1 10. The plurality of gears 1 30 may include a plurality of spur gears, such that the spur gears include a bull gear 1 32, a first pinion 134, and a second pinion 136. In an exemplary embodiment, the bull gear 1 32 may be fitted on the drive shaft 104 of the driver 1 02 by press fitting or any other manner known to those in the art, such that the bull gear 132 rotates at the same speed as the drive shaft 104. The first pinion 1 34 and second pinion 1 36 may be fitted on the respective rotary shafts 1 12 of the compressors 1 1 0 by press fitting, or any other manner known to those in the art, and configured such that a plurality of teeth (not shown) defined by each of the first and second pinion 1 34, 1 36 interconnect with the teeth (not shown) of the bull gear 1 32, thereby rotating the rotary shafts 1 1 2 of the respective compressors 1 1 0 at a speed consistent with the gearing ratio between the bull gear 1 32 and each of the first and second pinions 134, 136. The first pinion 134 and second pinion 1 36 may have identical diameters or the pinions 134, 1 36 may have differing diameters, thereby creating different gearing ratios with respect to the bull gear 132 and causing differing rotary speeds of the corresponding rotary shafts 1 1 2 of the compressors 1 1 0.

[0025] As shown in Figure 2, the first pinion 1 34 is operatively coupled to the respective rotary shafts 1 12 of the first compressor 1 1 8 and the second compressor 1 20. Likewise, the second pinion 136 is operatively coupled to the respective rotary shafts 1 12 of the third compressor 1 26 and fourth compressor 128. Embodiments in which the first and second compressors 1 1 8, 120 may be coupled via a common rotary shaft 1 12 and embodiments in which the third and fourth compressors 1 26, 1 28 may be coupled via a common rotary shaft 1 12 are contemplated herein.

[0026] In an exemplary embodiment, each compressor 1 10 may be a direct-inlet, centrifugal compressor. The direct-inlet or axial-inlet, centrifugal compressor may be, for example, a DATUM® ICS compressor manufactured by the Dresser-Rand Company of Olean, New York. In an exemplary embodiment, the compressors 1 10 illustrated in the sidestream mixing system 100 of Figure 1 may be axial-inlet, centrifugal compressors. In another exemplary embodiment of the sidestream mixing system 200 illustrated in Figure 2, each compressor 1 1 0 may be an integrally-geared compressor. The integrally-geared compressor may be, for example, an integrally-geared compressor from the Legacy ISOPAC and CVC lines of integrally-geared compressors manufactured by the Dresser- Rand Company of Olean, New York. Each integrally-geared compressor may be a single- stage compressor.

[0027] Each direct-inlet, centrifugal compressor of the sidestream mixing system 100 of Figure 1 may be a single-stage or a multi-stage compressor. Further, one of ordinary skill in the art will appreciate that varying combinations of single-stage compressors and multistage compressors may be employed in the sidestream mixing system 100 of Figure 1 . Still yet, the sidestream mixing system 100 may employ either all or substantially all single-stage compressors or all multi-stage compressors. One of ordinary skill in the art will appreciate that the number of stages provided in each compressor 1 1 0 may determine the number of compressors 1 1 0 required in the system. Correspondingly, embodiments in which a single compressor 1 1 0 is operatively coupled to a driver 1 02 are contemplated herein.

[0028] The plurality of compressors 1 10 may be fluidly coupled to each other via a network of piping 1 38. The piping 1 38 may be formed from a plurality of pipes, commonly referred to as lines or conduits, configured to fluidly connect the compressors 1 1 0 in series. The conduits may be further configured to flow therethrough one or more process fluids forming a process fluid stream having a measurable pressure, temperature, and/or mass flow rate. Accordingly, the conduit construction and sizing, e.g. , diameter, may vary based on the process fluid flowing therethrough and the accompanying pressure, temperature, and/or mass flow rate of the process fluid.

[0029] As shown in Figures 1 and 2, the piping 138 includes a system inlet 1 40 configured to provide an initial process fluid stream fed from a first external fluid source (not shown), such as, for example, a process fluid storage tank, to the sidestream mixing system 1 00, 200. The initial process fluid stream from the first external fluid source may have a first pressure (Pi), temperature (Ti), mass flow rate (Mi), and volumetric flow rate (Qi). The first external fluid source may be fluidly coupled to a first compressor inlet 142 of the first compressor 1 18 via the system inlet 140. The process fluid may be compressed in one or more stages in the first compressor 1 18 and discharged via a first compressor outlet 144 of the first compressor 1 18. The discharged process fluid , referred to as the first process fluid stream, includes the first mass flow rate (Mi), a second pressure (P ₂ ), a second volumetric flow rate (Ch), and a second temperature (T2), such that the second pressure (P2) and second temperature (T ₂ ) are greater than the first pressure (Pi) and temperature (T-i); however, because of the increased pressure and temperature, the second volumetric flow rate (Q ₂ ) is less than the first volumetric flow rate (Qi). The first compressor outlet 144 may be fluidly coupled to the second compressor 120 via a first conduit 1 46. In an exemplary embodiment, the first process fluid stream discharged from the first compressor outlet 1 42 may be fed through the first conduit 146, which forms a first junction 150 with a second conduit 1 52 upstream of the second compressor 120.

[0030] As shown in Figures 1 and 2, the first junction 150 may be a connection of a plurality of conduits 1 46,152 in the form of a "T"-junction, wherein the first conduit 1 46 and the second conduit 1 52 are fluidly coupled at the first junction 150 and the first conduit 1 46 further fluidly couples a second compressor inlet 154 of the second compressor 1 20 to the first junction 1 50. In another embodiment, the first junction may form a "Y" -junction. The second conduit 1 52 may be fluidly coupled to a second external fluid source (not shown) providing a second process fluid stream having a pressure (Psi), temperature (Tsi), mass flow rate (Ms-i), and volumetric flow rate (Qsi), such that at least the pressure (Psi) may be substantially similar to the second pressure (P ₂ ) and, optionally, the temperature (Tsi) may be substantially similar to the temperature (T2) of the first process fluid stream discharged from the first compressor outlet 1 44. As such, the second process fluid stream may be referred to as a first sidestream. The second external fluid source may be, for example, a pressurized fluid storage tank. The process fluid from the first compressor outlet 144 and the first sidestream may be mixed at the first junction 150 to form a first combined process fluid stream having a second mass flow rate (M ₂ ) and a third volumetric flow rate (Q3). In an exemplary embodiment, the second mass flow rate (M ₂ ) may be the summation of the first mass flow rate (M-i) and the mass flow rate (Msi), and the third volumetric flow rate (Q3) may be the summation of the second volumetric flow rate (Q ₂ ) and the volumetric flow rate (Qsi). The first combined process fluid stream may be fed to the second compressor inlet 1 54 via the first conduit 1 46.

[0031] The first junction 1 50 may be formed in the piping 1 38 at a distance of at least three pipe internal diameters upstream of the second compressor 1 20. For example, if the internal pipe diameter of the first conduit 1 46 is about eight inches (20.32 cm), the first junction 1 50 may be formed at least two feet (0.61 m) from the second compressor inlet 1 54. By mixing the first sidestream with the first process fluid stream at the first junction 1 50, the mixing of the process fluids is more efficient, and pressure and temperature stratification to disturb the impeller inlet flow is minimalized or eliminated.

[0032] The process fluid fed into the second compressor 120 via the first conduit 1 46 and the second compressor inlet 1 54 may be compressed in one or more stages and discharged via a second compressor outlet 158. The discharged process fluid referred to as the third process fluid stream includes the second mass flow rate (M ₂ ), a third pressure (P3), a fourth volumetric flow rate (Q ₄ ), and a third temperature (T3), such that the third pressure (P3) and third temperature (T3) are greater than the second pressure (P ₂ ) and temperature (T2); however, because of the increased pressure and temperature, the fourth volumetric flow rate (Q ₄ ) is less than the third volumetric flow rate (Q3). The second compressor outlet 1 58 may be coupled to the third compressor 1 26 via a third conduit 160. In an exemplary embodiment, the process fluid discharged from the second compressor outlet 158 may be fed through the third conduit 160 forming a second junction 164 with a fourth conduit 166 upstream of the third compressor 1 26.

[0033] As shown in Figures 1 and 2, the second junction 164 may be a connection of a plurality of conduits 160, 166 in the form of a "T"-junction, such that the third conduit 160 and the fourth conduit 166 are fluidly coupled at the second junction 1 64 and the third conduit 1 60 further fluidly couples a third compressor inlet 168 of the third compressor 1 26 to the second junction 164. In another embodiment, the first junction may form a "Y" -junction. The fourth conduit 1 66 may be fluidly coupled to a third external fluid source (not shown) providing a fourth process fluid stream having a pressure (Ps2), temperature (Ts2), mass flow rate (Ms2), and volumetric flow rate (Qs2), such that at least the pressure (Ps2) may be substantially similar to the third pressure (P3) and, optionally, the temperature (Ts2) may be substantially similar to the temperature (T3) of the third process fluid stream discharged from the second compressor outlet 1 58. As such, the fourth process fluid stream may be referred to as a second sidestream. The third external fluid source may be, for example, a pressurized fluid storage tank. The process fluid from the second compressor outlet 158 and the second sidestream may be mixed at the second junction 164 to form a second combined process fluid stream having a third mass flow rate (M3) and a fifth volumetric flow rate (Q5). In an exemplary embodiment, the third mass flow rate (M3) may be the summation of the second mass flow rate (M ₂ ) and the mass flow rate (Ms2), and the fifth volumetric flow rate (Q5) may be the summation of the fourth volumetric flow rate (Q ₄ ) and the volumetric flow rate (Qs2). The second combined process fluid stream may be fed to the third compressor inlet 1 68 via the third conduit 160.

[0034] The second junction 164 may be formed in the piping 1 38 at a distance of at least three pipe internal diameters upstream of the third compressor 126. For example, if the internal pipe diameter of the third conduit 160 is about eight inches (20.32 cm), the second junction 1 64 may be formed at least two feet (0.61 m) from the third compressor inlet 168. By mixing the second sidestream with the third process fluid stream at the second junction 1 64, the mixing of the process fluids is more efficient, and pressure and temperature stratification to disturb the impeller inlet flow is minimalized or eliminated.

[0035] The second combined process fluid stream fed into the third compressor 126 via the third conduit 1 60 and the third compressor inlet 1 68 may be compressed in one or more stages and discharged via a third compressor outlet 172. The discharged process fluid, referred to as a fifth process fluid stream, includes the third mass flow rate (M3), a fourth pressure (P ₄ ), a sixth volumetric flow rate (Q6), and a fourth temperature (T ₄ ), such that the fourth pressure (P ₄ ) and fourth temperature (T ₄ ) are greaterthan the third pressure (P3) and temperature (T3); however, because of the increased pressure and temperature, the sixth volumetric flow rate (Q6) is less than the fifth volumetric flow rate (Q5). The third compressor outlet 1 72 may be coupled to the fourth compressor 1 28 via a fifth conduit 174. In an exemplary embodiment, the fifth process fluid stream discharged from the third compressor outlet 172 may be fed through the fifth conduit 1 74 forming a third junction 178 with a sixth conduit 180 upstream of the fourth compressor 1 28.

[0036] As shown in Figures 1 and 2, the third junction 178 may be a connection of a plurality of conduits 174,180 in the form of a "T"-junction, wherein the fifth conduit 1 74 and the sixth conduit 180 are fluidly coupled at the third junction 1 78 and the fifth conduit 174 further fluidly couples a fourth compressor inlet 182 of the fourth compressor 1 28 to the third junction 1 78. In another embodiment, the third junction may form a "Y" -junction. The sixth conduit 180 may be fluidly coupled to a fourth external fluid source (not shown) providing a sixth process fluid stream having a pressure (Ps3), temperature (Ts3), mass flow rate (Ms3), and volumetric flow rate (Qs3), such that at least the pressure (Ps3) may be substantially similar to the fourth pressure (P ₄ ) and, optionally, the temperature (Ts3) may be substantially similar to the temperature (T ₄ ) of the fifth process fluid stream discharged from the third compressor outlet 1 72. As such, the sixth process fluid stream may be referred to as a third sidestream. The fourth external fluid source may be, for example, a pressurized fluid storage tank. The process fluid from the third compressor outlet 172 and the third sidestream may be mixed at the third junction 178 to form a third combined process fluid stream having a fourth mass flow rate (M ₄ ) and a seventh volumetric flow rate (Q ₇ ). In an exemplary embodiment, the fourth mass flow rate (M ₄ ) may be the summation of the third mass flow rate (IVb) and the mass flow rate (Ms3) , and the seventh volumetric flow rate (Q ₇ ) may be the summation of the sixth volumetric flow rate (Qe) and the volumetric flow rate (Qs3). The third combined process fluid stream may be fed to the fourth compressor inlet 1 82 via the fifth conduit 1 74.

[0037] The third junction 178 may be formed in the piping 138 at a distance of at least three pipe internal diameters upstream of the fourth compressor 1 28. For example, if the internal pipe diameter of the fifth conduit 174 is about eight inches (20.32 cm), the third junction 178 may be formed at least two feet (0.61 m) from the fourth compressor inlet 1 82. By mixing the third sidestream with the fifth process fluid stream at the third junction 178, the mixing of the process fluids is more efficient, and pressure and temperature stratification to disturb the impeller inlet flow is minimalized or eliminated.

[0038] The process fluid fed into the fourth compressor 128 via the fifth conduit 174 and the fourth compressor inlet 182 may be compressed in one or more stages and discharged via a fourth compressor outlet 1 86 having the mass flow rate (M ₄ ), a system outlet pressure (Ps), temperature (Ts), and volumetric flow rate (Qe). The fourth compressor outlet 186 may be coupled to a system outlet 188. The system outlet 188 may be further fluidly coupled to one or more downstream processing components (not shown) configured to further process the exiting process fluid.

[0039] Looking now at the exemplary embodiments illustrated in Figures 3 and 4, a system 300, 400 is provided for removing via one or more sidestreams at least a portion of a process fluid. The process fluid removal system 300, 400 may be similar in some respects to the sidestream mixing system 100, 200 described above and therefore may be best understood with reference to the description of Figures 1 and 2 where like numerals designate like components and will not be described again in detail.

[0040] The piping 1 38 includes a system inlet 1 40 configured to provide an initial process fluid stream fed from a first external fluid source (not shown), such as, for example, a process fluid storage tank, to the process fluid removal system 300, 400. The initial process fluid stream from the first external fluid source may have a first pressure (Pi), temperature (T-i), mass flow rate (M-i), and volumetric flow rate (Qi). The first external fluid source may be fluidly coupled to a first compressor inlet 1 42 of the first compressor 1 18 via the system inlet 1 40. The process fluid may be compressed in one or more stages in the first compressor 1 18 and discharged via a first compressor outlet 1 44 of the first compressor 1 18. The discharged process fluid, referred to asthe first process fluid stream, includes the first mass flow rate (Mi), a second pressure (P ₂ ), a second volumetric flow rate (Q ₂ ), and a second temperature (T ₂ ), such that the second pressure (P ₂ ) and second temperature (T ₂ ) are greater than the first pressure (P-i) and temperature (Ti); however, because of the increased pressure and temperature, the second volumetric flow rate (Q ₂ ) is less than the first volumetric flow rate (Qi). The first compressor outlet 1 44 may be fluidly coupled to the second compressor 120 via a first conduit 146. In an exemplary embodiment, the first process fluid stream discharged from the first compressor outlet 142 may be fed through the first conduit 146, which forms a first junction 1 50a with a second conduit 152a upstream of the second compressor 120.

[0041] The first junction 150a may be a connection of a plurality of conduits 146,152a in the form of a "T"-junction, wherein the first conduit 146 and the second conduit 152a are fluidly coupled at the first junction 1 50a, and the first conduit 146 further fluidly couples the second compressor inlet 154 of the second compressor 120 to the first junction 150a. In another embodiment, the first junction may form a "Y" -junction. The second conduit 1 52a may be fluidly coupled to a first external process component (not shown) and may provide the first external process component with a portion of the first process fluid stream compressed from the first compressor 1 1 8 and having a pressure (Psi), temperature (Tsi), mass flow rate (Msi), and volumetric flow rate (Qsi). The portion of the first process fluid stream fed to the first external process component from the first junction 150a may be referred to as the primary sidestream and may be fed to the first external process component via the second conduit 152a. The remaining process fluid stream of the first process fluid stream may have a second mass flow rate (M ₂ ) and a third volumetric flow rate (Cb). In an exemplary embodiment, the second mass flow rate (M ₂ ) may be the difference between the first mass flow rate (Mi) and the mass flow rate (Msi), and the third volumetric flow rate (C ) may be the difference between the second volumetric flow rate (Q ₂ ) and the volumetric flow rate (Qsi). The remaining process fluid stream of the first process fluid stream may be fed to the second compressor inlet 154 via the first conduit 146. The first junction 150a may be formed in the piping 1 38 at least three pipe internal diameters upstream of the second compressor 120.

[0042] The process fluid fed into the second compressor 120 via the first conduit 146 and the second compressor inlet 154 may be compressed in one or more stages and discharged via a second compressor outlet 158. The discharged process fluid referred to as the third process fluid stream includes the second mass flow rate (M ₂ ), a third pressure (P3), a fourth volumetric flow rate (Q ₄ ), and a third temperature (T3), such that the third pressure (P3) and third temperature (T3) are greater than the second pressure (P ₂ ) and temperature (T2); however, because of the increased pressure and temperature, the fourth volumetric flow rate (Q ₄ ) is less than the third volumetric flow rate (Q3). The second compressor outlet 1 58 may be coupled to the third compressor 1 26 via a third conduit 160. In an exemplary embodiment, the process fluid discharged from the second compressor outlet 158 may be fed through the third conduit 1 60 forming a second junction 164a with a fourth conduit 1 66a upstream of the third compressor 126.

[0043] In the exemplary embodiments illustrated in Figures 3 and 4, the second junction 1 64a may be a connection of a plurality of conduits 1 60,166a in the form of a "T"-junction, wherein the third conduit 1 60 and the fourth conduit 166a are fluidly coupled at the second junction 1 64a, and third conduit 160 further fluidly couples the third compressor inlet 168 of the third compressor 126 to the second junction 1 64a. In another embodiment, the second junction 1 64a may form a "Y"-junction. The fourth conduit 166a may be fluidly coupled to a second external process component (not shown) and may provide the second external process component with a portion of the third process fluid stream compressed from the second compressor 1 20 and having a pressure (Ps2), temperature (Ts2), mass flow rate (Ms2), and volumetric flow rate (Qs2). The portion of the third process fluid stream fed to the second external process component from the second junction 1 64a may be referred to as the secondary sidestream and may be fed to the second external process component via the fourth conduit 166a. The remaining process fluid stream of the third process fluid stream may have a third mass flow rate (M3) and a fifth volumetric flow rate (Q5). In an exemplary embodiment, the third mass flow rate (M3) may be the difference between the second mass flow rate (M ₂ ) and the mass flow rate (Ms2), and the fifth volumetric flow rate (Qs) may be the difference between the fourth volumetric flow rate (Q ₄ ) and the volumetric flow rate (Qs2). The remaining process fluid stream of the third process fluid stream may be fed to the third compressor inlet 168 via the third conduit 1 60. The second junction 1 64a may be formed in the piping 1 38 at a distance of at least three pipe internal diameters upstream of the third compressor 1 26.

[0044] The second combined process fluid stream fed into the third compressor 126 via the third conduit 1 60 and the third compressor inlet 1 68 may be compressed in one or more stages and discharged via a third compressor outlet 172. The discharged process fluid, referred to as a fifth process fluid stream, includes the third mass flow rate (IVb), a fourth pressure (P ₄ ), a sixth volumetric flow rate (Qe), and a fourth temperature (T ₄ ), such that the fourth pressure (P ₄ ) and fourth temperature (T ₄ ) are greaterthan the third pressure (P3) and temperature (T3); however, because of the increased pressure and temperature, the sixth volumetric flow rate (Q6) is less than the fifth volumetric flow rate (Q5). The third compressor outlet 1 72 may be coupled to the fourth compressor 128 via a fifth conduit 174. In an exemplary embodiment, the fifth process fluid stream discharged from the third compressor outlet 1 72 may be fed through the fifth conduit 174 forming a third junction 1 78a with a sixth conduit 1 80a upstream of the fourth compressor 128.

[0045] In the exemplary embodiments illustrated in Figures 3 and 4, the third junction 1 78a may be a connection of a plurality of conduits 174, 180a in the form of a "T"-junction, wherein the fifth conduit 174 and the sixth conduit 180a are fluidly coupled at the third junction 178a, and the fifth conduit 1 74 further fluidly couples the fourth compressor inlet 1 82 of the fourth compressor 1 28 to the third junction 178a. In another embodiment, the third junction 1 78a may form a "Y"-junction. The sixth conduit 180a may be fluidly coupled to a third external process component (not shown) and may provide the third external process component with a portion of the fifth process fluid stream compressed from the third compressor 1 26 and having a pressure (Ps3), temperature (Ts3), mass flow rate (Ms3), and volumetric flow rate (Qs3). The portion of the fifth process fluid stream fed to the third external process component from the third junction 1 78a may be referred to as the tertiary sidestream and may be fed to the third external process component via the sixth conduit 1 80a. The remaining process fluid stream of the fifth process fluid stream may have a fourth mass flow rate (M ₄ ) and a seventh volumetric flow rate (Q ₇ ). In an exemplary embodiment, the fourth mass flow rate (M ₄ ) may be the difference between the third mass flow rate (M3) and the mass flow rate (Ms3), and the seventh volumetric flow rate (Q ₇ ) may be the difference between the sixth volumetric flow rate (Q6) and the volumetric flow rate (Qs3). The remaining process fluid stream of the fifth process fluid stream may be fed to the fourth compressor inlet 182 via the fifth conduit 174. The third junction 178a may be formed in the piping 138 at least three pipe internal diameters upstream of the fourth compressor 1 28.

[0046] The process fluid fed into the fourth compressor 1 28 via the fifth conduit 1 74 and the fourth compressor inlet 182 may be compressed in one or more stages and discharged via a fourth compressor outlet 186 having the mass flow rate (M ₄ ), a system outlet pressure (Ps), temperature (T5), and volumetric flow rate (Qe). The fourth compressor outlet 186 may be coupled to a system outlet 188. The system outlet 188 may be further fluidly coupled to one or more downstream processing components (not shown) configured to further process the exiting process fluid.

[0047] Figure 5 illustrates a flowchart of an exemplary method 500 for mixing and pressurizing a plurality of process fluid streams. The method 500 may include driving a rotary shaft of at least one compressor via a first drive shaft operatively coupled to the rotary shaft, the first drive shaft driven by a first driver, as at 502. The method 500 may also include feeding a first process fluid stream of the plurality of process fluid streams through a first conduit having a first conduit diameter and fluidly coupled to the at least one compressor, as at 504. The method 500 may further include feeding a second process fluid stream of the plurality of process fluid streams through a second conduit coupled to the first conduit at a first junction disposed upstream of the at least one compressor a first distance of at least three times the first conduit diameter, as at 506. The method 500 may also include mixing the first process fluid stream and the second process fluid stream at the first junction, thereby forming a first combined process fluid stream , as at 508. The method 500 may further include feeding the first combined process fluid stream into the at least one compressor, as at 510, and pressurizing the first combined process fluid stream in the at least one compressor, as at 512.

[0048] Figure 6 illustrates a flowchart of an exemplary method 600 for removing at least a portion of a process fluid stream . The method 600 may include driving a rotary shaft of at least one compressor via a drive shaft operatively coupled to the rotary shaft, the drive shaft driven by a driver, as at 602. The method 600 may also include feeding the process fluid stream through a first conduit having a first conduit diameter and being fluidly coupled to the at least one compressor, as at 604. The method 600 may further include feeding the at least a portion of a process fluid stream through a second conduit coupled to the first conduit at a first junction disposed upstream of the at least one compressor a distance of at least three times the first conduit diameter, thereby removing the at least a portion of the process fluid stream from the process fluid stream, as at 606.

[0049] The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.