Inline Static Mixer

Abstract

The in-line static mixer (100) includes an outer tube (112) and an inner tube (104) disposed inside the outer tube and configured coaxially with the outer tube, and has a space (104) between the inner tube and the outer tube. The inner tube is operable to receive and convey a hydrocarbon stream, and the outer tube is operable to receive and convey a diluent stream. At least one baffle (114) extends from the inner tube toward the outer tube through at least a portion of the space and is operable to generate a twisted diluent flow from the diluent stream. The twisted diluent flow and the hydrocarbon stream are mixed downstream of the outlet of the inner tube, and the twisted diluent flow forms a boundary layer along the inner surface of the outer tube to minimize fouling resulting from the liquid or droplets of the hydrocarbon stream after mixing.

Description

Technical Field

[0001] The present disclosure generally relates to static mixers, and more particularly, but not exclusively, to in-line static mixers having a flow twister for mixing fluid streams.

Background Art

[0002] Static mixers are known to be used in petrochemical processes, particularly in the production of ethylene and / or propylene. In conventional static mixers, two fluid streams, for example, a gaseous diluent stream and a feed stream (which may be liquid, partially liquid and partially vapor, or contain droplets), are mixed. The mixed feed-diluent mixture is then fed to a heater to produce a heated feed-diluent mixture in preparation for further processing.

[0003] In previous mixer designs, the streams were mixed in the mechanical parts or immediately after the mechanical parts. More specifically, in such designs, the diluent and the hydrocarbon feedstock were mixed by direct contact within the mixing device before indirectly heating the mixture in the tube of the convection section. In practice, since liquids or droplets do not vaporize immediately and require a certain length to reach thermal equilibrium, the liquid necessarily contacts the heated wall of the tube in the convection section, leaving fouling deposits. In other words, if there are any droplets, the droplets may collide with the mechanical parts downstream of the mixer or the contact surfaces of the mechanical parts, generating fouling over time. Such deposits must be removed by daily cleaning, increasing the operating costs, decreasing the yield over time, and increasing the maintenance downtime. Alternatively, such deposits can restrict the flow and reduce the throughput of the heater, resulting in a decreased yield. In addition, depending on the static mixer, a large pressure loss may occur, decreasing the yield, or alternatively, increasing the operating cost of the compressor to change the pressure to obtain the desired yield. Accordingly, certain solutions have been proposed, but such solutions have various defects and drawbacks.

[0004] For example, one solution is a device that promotes mixing at different stages along the fluid flow to help achieve a more uniform mixing of the single-phase flow. In such an example, the concentration distribution or temperature distribution of the fluid in the direction of flow is constant. However, fouling deposits may still occur at various mixing stages, and separate stages may lead to a large pressure loss.

[0005] Alternative solutions are to create a more turbulent flow through the device and promote the mixing of two streams or a single stream by varying the flow area along the flow path. However, this solution also causes significant pressure losses. As a further solution, there is a coaxial static mixer that brings the two streams into contact inside the device, but such a solution also tends to leave fouling deposits. In some variations, the coaxial static mixer generates two opposing rotational flows to provide more mixing with each other, but the applicability may be limited to streams that are not likely to foul.

[0006] Still other mixers promote the mixing of a single stream. Such mixers include spoilers that apply force to the fluid flow from an external source to create wavy mixing. Such solutions increase the overall complexity of the mixer and can generate significant pressure losses. In some variations, the single-stream fluid flow is instead divided into different sections. Since the flow area varies in each section in the flow direction, the flow velocity changes, being high in some sections and low in others. Streams from the various sections merge and mix, but fouling may occur at such mixing locations.

[0007] Among conventional static mixers, there are those having a stack of mixing elements or a similar structure. Adjacent elements direct the flow in opposite directions as the fluid flows through the elements. This solution can reduce fouling for a single stream, but tends to result in significant pressure losses associated with the redirection of the fluid.

[0008] Therefore, there is a need for a static mixer that overcomes the deficiencies and drawbacks of known static mixers. SUMMARY OF THE INVENTION

[0009] The present disclosure generally relates to in-line static mixing devices, systems, and methods for hydrocarbon processing applications. In particular, the mixers of the present disclosure may include a flow twist device provided with a helical blade profile factor in one or both of the tubes for generating a swirling flow within the mixer that forms a boundary layer with high diluent vapor and low hydrocarbon along the mechanical components. Such a configuration is advantageous for mixing streams without significant pressure drop while minimizing contact between the hydrocarbon and the mechanical components to reduce fouling or deposition of impurities. In particular, the concept of the present disclosure also minimizes any potential hydrocarbon fouling or deposition of any impurities on the inner surface of the heating coil.

[0010] In one or more embodiments, a method is provided for introducing a liquid or partially liquid hydrocarbon feedstock together with a diluent into a cracking heater to produce a superheated feedstock-diluent mixture. The diluent stream and the hydrocarbon stream are coaxially introduced into the convective section such that the vapor diluent is on the outside and the liquid or partially liquid hydrocarbon stream is on the inside. The swirling flow may be imparted to either or both of the hydrocarbon or diluent flows. The cracking heater has a heating surface within the convective section for preheating the hydrocarbon feedstock. Diluent vapor is added to the hydrocarbon to preferably promote vaporization of the hydrocarbon relative to the liquid feed to the heater and to reduce the hydrocarbon partial pressure within the stream to obtain an optimal yield such as a yield of ethylene and / or propylene.

[0011] In one or more embodiments, the mixing device includes an in-line flow swirl device. The mixing device is installed along the hydrocarbon stream and includes a branch connection to the dilution vapor to be mixed with the hydrocarbon. Before the vapor mixes with the hydrocarbon, the device generates a swirling flow near the inner surface of the heating coil to form a boundary layer where the dilution vapor is high and the hydrocarbon is low. The boundary layer delays, prevents, or minimizes the contact of hydrocarbon droplets with the inner surface of the heater coil before the hydrocarbon is completely vaporized. At the same time, the swirling dilution vapor flow promotes the desired flow mixing between the hydrocarbon and the dilution vapor. It is preferable to completely vaporize the droplets before they enter the heated surface section to reduce fouling and deposition of impurities. In one or more embodiments of the device, any remaining hydrocarbon droplets are separated by the dilution vapor boundary layer and completely vaporized before reaching the heated surface section. As a result, the risk of surface fouling by heavy hydrocarbon components or impurities is minimized by the device.

Brief Description of the Drawings

[0012]

Figure 1A

Figure 1B

Figure 1C

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Figure 7A

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Figure 7C

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MODE FOR CARRYING OUT THE INVENTION

[0013] The present disclosure proceeds to describe certain non-limiting examples of technologies that can be particularly advantageous for petrochemical processing and refining (e.g., for the production of ethylene and / or propylene using at least a steam cracking heater). However, it will be understood that the concepts of the present disclosure can be applied to a wide range of technologies and industries. In particular, the concepts of the present disclosure can be equally applied to any industry or technology that utilizes a firing or heating process involving the mixing of two streams, and in particular, to a two-phase flow for completely vaporizing the flow after mixing. Such concepts can also be introduced into new heaters or retrofitted into existing heaters to improve heater performance and reduce heater downtime for maintenance.

[0014] Figures 1A - 1C are schematic diagrams of a known static mixer 20 to provide further context regarding the benefits and advantages of the concepts of the present disclosure. In the known static mixer 20, a hydrocarbon stream 22 (Stream A) and a dilution stream 24 (Stream B) are mixed through a direct pipe connection. Figures 1A - 1C show variations in the mixing location and mixer orientation. The mixed mixture is then supplied to a heating surface 28 along pipe 26, and the mixture is heated for further downstream processing. If the hydrocarbon stream 22 contains heavy components or impurities, droplets (especially from the hydrocarbon stream 22) may wet and accumulate on the inner surface of the pipe 26. As the liquid moves to the heating surface 28, the combination of the incident heat and the liquid in the pipe 26 leads to fouling that ultimately restricts the flow through the pipe 26 and the heating surface 28 (which may also be the pipe 28). As used herein, "fouling" may refer to insoluble substances or deposits that accumulate on mechanical components, including, without limitation, scaling, corrosion, sludge, and debris. Additionally, it includes the formation of deposits by vaporization of higher molecular weight components of the hydrocarbon feedstock on the heated surface. This deposit gradually accumulates and hardens over time, leading to significant pressure loss and insufficient heat transfer in the heated section. Accordingly, it may be necessary to stop the mixer 20 and the entire system for cleaning and maintenance, or the throughput of the heater may decrease due to a reduction in fluid flow.

[0015] Known mixers (e.g., mixer 20) perform mixing at flow spoilers or create a mixing that does not prevent droplets from contacting downstream mechanical surfaces. As a result, the operation of known mixers is likely to lead to fouling of mechanical components and related disadvantages.

[0016] In contrast, the concept of the present disclosure keeps the two streams separate in order to prevent or minimize the vaporization of droplets before the flow pattern is fully developed. When the flow pattern develops, the two streams are mixed, but the stream with droplets is separated from the mechanical surface or, if there is any contact with the mechanical surface, the contact is delayed, minimizing potential fouling.

[0017] Figures 2 and 3 are schematic diagrams of one or more embodiments of an in-line flow mixer 100 (which may also be referred to herein as in-line mixer 100 or mixer 100) according to the present disclosure. A hydrocarbon stream 102 (stream A) (which may contain droplets) flows through an inner tube 104. A diluent stream 106 (stream B) flows through a nozzle 108 and through a space 110 between the inner tube 104 and an outer tube 112. In one embodiment, as further described herein, the diluent stream is a gas stream (such as vapor) that causes vaporization of the hydrocarbon stream 102 after mixing. The diluent stream 106 flows around several helical baffle plates 114. In some embodiments, the mixer 100 includes three or more baffle plates 114, or more preferably, six to eight baffle plates 114. Of course, the mixer 100 may include a selected number of baffle plates 114 that is more or less than the non-limiting examples above.

[0018] The baffle plate 114 may be configured around the inner tube 104 and may be coupled to the inner tube 104, and may extend around the inner tube 104 while rotating helically completely and continuously along at least a portion of the length of the inner tube 104. In one embodiment, the baffle plate 114 extends less than half, half, or more than half of the length of the inner tube 104 and all the way to the whole. Further, the baffle plate 114 may have a selected height with respect to the inner tube 104 and the outer tube 112 (i.e., the baffle plate 114 extends from the inner tube 104 through a selected amount of the space 110 between the inner tube 104 and the outer tube 112). In some embodiments, the baffle plate 114 extends longitudinally (i.e., in the vertical direction in the orientation of FIG. 2) through less than half, half, more than half, or any whole of the space 110, in which case the baffle plate 114 contacts the inner tube 104 and either contacts or is very close to the outer tube 112. In one embodiment, the baffle plate 114 has a manufacturing or fabrication tolerance between the outer peripheral edge of the baffle plate 114 and the inner surface of the outer tube 112 and is welded only to the inner tube 104. Further, the baffle plate 114 may be disposed at one end of the inner tube 104 closest to the mixing interface between the streams 102, 106, as best shown in FIG. 3. The baffle plate 114 preferably forms an angle 116 of 30 to 45 degrees with respect to the flow axis 118 defined by the hydrocarbon stream 102 (i.e., the horizontal axis passing through the center of the inner tube in the orientation of FIG. 2), including all intervening values to at least two decimal places and including the limiting values. In some embodiments, the angle 116 is less than 30 degrees or more than 45 degrees. Further, each baffle plate 114 may have a selected spacing with respect to other baffle plates 114, which may be as low as 6 inches to 1 foot or more than 1 foot, for example, at least 3 feet, 4 feet, 5 feet, or more. The angling of the helical baffle plates 114 with respect to the tubes 104, 112 and the spacing between the plates 114 allow a twisted flow of the diluent stream 106 along the space 110 during operation.

[0019] In one embodiment, the length of the inner tube 104 is less than the length of the outer tube 112, and the inner tube 104 terminates (i.e., has an outlet) inside the outer tube 112. The diluent stream 106 flows through the space 110 and through the baffle development 114 to form a swirling flow. After the swirling flow is fully developed, the two streams 102, 106 mix at the outlet of the inner tube 104. The swirling flow of the diluent stream 106 generated by the baffle 114 moves along the inner surface 119 of the outer tube 112 and forms a boundary layer along the inner surface of the outer tube 112 represented by the dashed line 121 in FIG. 2. The boundary layer 121 prevents or minimizes the liquid and / or droplets in the hydrocarbon stream 102 exiting the inner tube 104 from contacting the inner surface 119 and causing fouling on the inner surface 119. Further, the liquid and / or droplets reaching the boundary layer 121 may be vaporized by the swirling flow of the diluent 106, which can be heated before being provided to the outer tube 112. The tubes 104, 112 are coaxially configured, and since the hydrocarbon stream 102 crosses the inner tube 102 substantially without changing direction, the pressure drop in the mixer 100 is minimal. Further, the swirling flow generated by the baffle 114 also advantageously mixes the streams 102, 106.

[0020] As shown in FIG. 4, in some embodiments, the mixer 100 may include only two coaxial tubes (i.e., the inner tube 104 and the outer tube 112) without the baffle plate 114. As shown in FIG. 5, the mixer 100 may include only a twister plate 120 (also referred to herein as a swirling baffle plate 120) inside the inner tube 104 instead of the baffle plate 114. In one embodiment, the twister plate 120 may have some or all of the same characteristics described above for the baffle plate 114, only differing in its position within the mixer 100.

[0021] In one embodiment, as shown in FIG. 6, the mixer 100 includes both a twister plate 120 inside the inner tube 104 and a spiral baffle plate 114. The spiral baffle plate 114 and the twisted baffle plate 120 may have the same or different angles with respect to the flow axis 118, and may generate a rotational flow or a twisted flow in the same or opposite directions within the inner and outer coaxial tubes 104, 112.

[0022] The mixer 100 can be installed in various locations and orientations depending on design factors and available mechanical space. For example, in FIG. 7A, the mixer 100 is installed according to the normal meaning of "vertical" (i.e., gravity pulls an object along a vertical path), is aligned vertically, has an upward flow after mixing, and helps suspend the vaporizing droplets. In one embodiment, the pipe 122 from the mixer 100 to the heating surface 124 may have a straight length of 10 to 15 times the inner diameter of the pipe 122 before any flow disturbance, and may have a total straight length of 20 to 30 times the inner diameter of the pipe that allows a space for vaporization to be completed before entering the heating surface section 124. The configuration of FIG. 7A may provide more time for a process stream containing very heavy components to be completely vaporized before reaching the heating surface 124 in order to avoid fouling.

[0023] The mixer 100 can also be installed so as to be configured horizontally, as shown in FIG. 7B. In one embodiment, it is preferable that the straight pipe length and the total straight pipe length are comparable after mixing. Such a configuration may enable a process stream having moderately heavy components to be completely vaporized before entering the heating surface 124.

[0024] When the mechanical space is limited, the mixer 100 can be installed as shown in FIG. 7C. More specifically, the mixer 100 can be installed immediately before a linear heating pipe leading to the heating surface 124. In such an embodiment, it is preferable to increase the angle 116 of the baffle plate 114 with respect to the flow axis 118 (FIG. 2) in order to provide a more concentrated helical flow path. The more concentrated flow path increases the heat transfer rate, allowing the diluent stream 106 to reach a higher temperature while mixing with the hydrocarbon stream 102 (FIG. 2). The greater the angle, the more powerful the mixing between the streams 102, 106 is also promoted. The higher the temperature of the diluent stream 106 and the more powerful the mixing, the more quickly the droplets are vaporized, helping to minimize the risk of fouling on the heating surface 124.

[0025] Figures 8-10 are outputs from a computational fluid dynamics (CFD) simulation, showing the flow trajectories obtained using the embodiments of the mixer 100 described herein. The simulation has confirmed that the tube design of the mixer 100 effectively prevents or minimizes the central stream within the inner tube 104 from reaching the inner surface of the outer tube 112 (FIG. 2), preventing or minimizing fouling. In particular, embodiments involving helical flow (whether via the helical baffle plate 114, the helical plate 120, or both) promote faster mixing while further improving the separation of the central stream from the inner surface of the outer tube 112 (FIG. 2). In FIGS. 8-10, the boundary layer with high diluent and low hydrocarbon is represented by the outer dark line, and the hydrocarbon stream is the inner lighter line.

[0026] Considering the above, the mixer 100 described in this specification has many benefits and advantages. For example, the mixer 100 may keep the two streams separate and, as a flow pattern, form a flow pattern that keeps the droplets in a suspended state and allows complete vaporization before the droplets contact the solid surface. Further, the two streams may not be intentionally fully mixed before exiting the mixing device. Instead, the high temperature of the wall of the convective section is utilized to form a boundary layer of the diluent that is rapidly heated to a high temperature. In such a configuration, the Leidenfrost effect is substantially utilized. This is because the diluent is heated to a high temperature on the inner wall of the tube, and the vaporization of the droplets in the mixed fluid stream is promoted more strongly than the vaporization of the droplets on the tube wall.

[0027] Furthermore, in contrast to the vaporization of the droplets at the heated surface downstream of the mixing device, the concentration and temperature distributions may not be constant within the mixer to promote the vaporization of the droplets within the main flow. In some embodiments, to improve vaporization, once the flow is fully formed, the two streams may be mixed only at the outlet of the device.

[0028] In some embodiments, the mixer of the present disclosure mixes two streams. One is a gas and the other contains a liquid or droplets. At the mixing point, the liquid or droplets can vaporize. During the vaporization process, any heavy components in the liquid may cause fouling on mechanical surfaces such as the inner surfaces of the transport pipes, containers, or mixer components. The mixer of the present disclosure includes two coaxial pipes that keep the two streams separate before mixing. The stream without fouling flows through the outer pipe, and the stream that may have fouling flows through the inner pipe. Between the inner pipe and the outer pipe, the mixer may include a helical baffle that generates a twisted flow within the stream without fouling before exiting the section of the coaxial pipe. The twisted flow forms a boundary layer that can prevent or minimize the contact of the stream with liquid and / or droplets with the pipe surface. The droplets gradually mix with the stream and vaporize near the pipe surface, minimizing the possibility that the liquid contacts the pipe surface and causes fouling.

[0029] In one embodiment, the mixer includes an outer pipe, a nozzle communicating with the outer pipe, an inner pipe located inside the outer pipe and having an inlet, the inner pipe being operable to receive a hydrocarbon stream through the inlet and convey the hydrocarbon stream along a flow path through the inner pipe from the inlet to the outlet of the inner pipe, a space between the inner pipe and the outer pipe, the outer pipe being operable to receive a diluent stream through the nozzle and convey the diluent stream through the space, at least one baffle coupled to the inner pipe and extending from the inner pipe toward the outer pipe through at least a portion of the space, the at least one baffle being operable to generate a twisted diluent flow from the diluent stream, the twisted diluent flow and the hydrocarbon stream being mixed downstream of the outlet of the inner pipe, and the twisted diluent flow forming a boundary layer along the inner surface of the outer pipe.

[0030] In one embodiment, the inner tube is configured coaxially with respect to the outer tube, the length of the inner tube is shorter than the length of the outer tube, and the boundary layer is operable to prevent or minimize contact of the liquid in the hydrocarbon stream with the inner surface of the outer tube.

[0031] In one embodiment, at least one baffle is a plurality of helical baffles extending around the inner tube, and the plurality of helical baffles have an angle of 30 degrees to 45 degrees with respect to the flow axis passing through the inner tube.

[0032] In one embodiment, the inner tube includes at least one twister plate operable to generate a twisted hydrocarbon flow from the hydrocarbon stream.

[0033] In one embodiment, at least one baffle is a helical baffle on the outer surface of the inner tube.

[0034] In one embodiment, the boundary layer is operable to prevent or minimize contact of the liquid in the hydrocarbon stream with the inner surface of the outer tube.

[0035] In one embodiment, the mixer includes an outer tube, an inner tube inside the outer tube and configured coaxially with respect to the outer tube, the inner tube having an inlet and being operable to receive a hydrocarbon stream through the inlet and convey the hydrocarbon stream along a flow path through the inner tube from the inlet to the outlet of the inner tube disposed inside the outer tube, a space between the inner tube and the outer tube, the outer tube being operable to receive a diluent stream and convey the diluent stream through the space, and the diluent stream and the hydrocarbon stream are mixed downstream of the outlet of the inner tube, and the diluent stream forms a boundary layer along the inner surface of the outer tube to prevent liquid or droplets from the hydrocarbon stream from contacting the inner surface of the outer tube.

[0036] In one embodiment, the mixer further includes at least one baffle coupled to the inner tube and extending from the inner tube toward the outer tube through at least a portion of the space, the at least one baffle being operable to generate a twisted diluent flow from the diluent stream, the twisted diluent flow forming a boundary layer.

[0037] In one embodiment, the at least one baffle is a plurality of spiral baffles extending around the inner tube, the plurality of spiral baffles having an angle of 30 degrees to 45 degrees with respect to the flow axis through the inner tube.

[0038] In one embodiment, the inner tube includes at least one twister plate operable to generate a twisted hydrocarbon flow from the hydrocarbon stream.

[0039] In one embodiment, the rotational direction of the twisted diluent flow is the same as the rotational direction of the twisted hydrocarbon flow.

[0040] In one embodiment, the rotational direction of the twisted diluent flow is opposite to the rotational direction of the twisted hydrocarbon flow.

[0041] In one embodiment, the inner tube includes at least one twister plate operable to generate a twisted hydrocarbon flow from the hydrocarbon stream.

[0042] In one embodiment, the mixer includes an outer tube, an inner tube configured within the outer tube, the inner tube being operable to receive a hydrocarbon stream and convey the hydrocarbon stream through the inner tube, and a space between the inner tube and the outer tube, the outer tube being operable to receive a diluent stream and convey the diluent stream through the space, the diluent stream and the hydrocarbon stream being mixed downstream of the outlet of the inner tube, the diluent stream being configured to form a boundary layer along the inner surface of the outer tube to prevent or minimize contact of liquid or droplets from the hydrocarbon stream with the inner surface of the outer tube.

[0043] In one embodiment, the inner tube includes at least one baffle on the outer surface of the inner tube, and the at least one baffle is operable to generate a swirling diluent flow that forms a boundary layer from the diluent stream.

[0044] In one embodiment, the at least one baffle is configured on the outer surface of the inner tube at an angle of 30 degrees to 45 degrees with respect to the flow axis through the inner tube.

[0045] In one embodiment, the inner tube includes at least one twister plate.

[0046] In one embodiment, the inner tube includes at least one twister plate inside the inner tube operable to generate a swirling hydrocarbon flow and at least one baffle outside the inner tube operable to generate a swirling diluent flow that forms a boundary layer.

[0047] In one embodiment, the inner tube is configured coaxially with respect to the outer tube.

[0048] In one embodiment, a portion of the length of the inner tube is accommodated within the outer tube, and the inner tube further includes a flow control device that is at least one baffle or at least one twister plate, and the flow control device extends along less than the entire length of a portion of the inner tube.

[0049] In the above description, specific specific details have been described to obtain a complete understanding of the various embodiments of the present disclosure. However, as will be understood by those skilled in the art, the present disclosure can be practiced without such specific details. In other instances, well-known structures related to the present technology have not been described in detail to avoid unnecessarily obscuring the description of the embodiments of the present disclosure.

[0050] The following describes specific terms and phrases used in this specification. Throughout this document, including the claims, the singular forms "a", "an", and "the" include plural references unless otherwise specified. Any of the features and elements described in this specification may be singular; for example, a shell may refer to one shell. The terms "include" and "comprise" and their derivatives mean including without limitation.

[0051] The use of ordinal numbers such as first, second, third, etc. does not necessarily mean ranking in order; rather, it may only distinguish multiple instances of an act or similar structures and materials.

[0052] Throughout this specification and the claims, the following terms take at least the meanings explicitly associated with them in this specification, unless the context clearly indicates otherwise. The term "herein" refers to the specification, claims, and drawings related to this application. Phrases such as "in one embodiment", "in another embodiment", "in various embodiments", "in some embodiments", "in other embodiments", and their derivatives refer to one or more features, structures, functions, limitations, or characteristics of this disclosure and are not limited to the same or different embodiments unless the context clearly indicates otherwise. As used in this specification, the term "or" is an inclusive "or" operator and is equivalent to the expressions "A or B, or both" or "A or B or C, or any combination thereof", and lists with additional elements are treated similarly.

[0053] The terms "top," "bottom," "upper," "lower," "above," "below," "exceed," "fall below," "left," "right," and other similar derivatives have a general meaning as indicators of direction or position. For example, gravity pulls an object downward, and left refers to the direction that is west when facing north on a basic compass. These terms are not intended to limit the orientations that may be explicitly, implicitly, or inherently disclosed in this disclosure. Unless the context clearly indicates a different meaning, any aspect of the embodiments of this disclosure can be arranged in any orientation.

[0054] Unless the context clearly indicates otherwise, relative terms such as "about," "substantially," and other derivatives are to be construed as including the normal error range or manufacturing tolerances due to minor manufacturing differences or variations. When used to describe a value, amount, quantity, or dimension, it generally refers to a value, amount, quantity, or dimension within plus or minus 5% of the stated value, amount, quantity, or dimension. Additionally, any specific dimension of a component or feature provided herein is for illustrative purposes only with reference to the various embodiments described herein. As such, it is to be understood that the disclosure explicitly contemplates dimensions greater than or less than the stated dimensions unless the context clearly indicates otherwise. All ranges of dimensions and other values include all possible intervening values and limiting values unless the context clearly indicates otherwise.

[0055] This application claims priority to U.S. Provisional Application No. 63 / 351,755, filed with the United States Patent and Trademark Office on June 13, 2022. The entire contents of this document are hereby incorporated by reference into this specification.

[0056] In view of the foregoing detailed description, these and other modifications can be made to the embodiments. Generally, in the following claims, the terms used should not be construed as limiting the claims to the specific embodiments disclosed in the specification and claims, but rather the claims should be construed to include all possible embodiments together with the full scope of equivalents to which such claims are entitled. Accordingly, the breadth and scope of the disclosed embodiments should not be limited by any of the above-described embodiments, but should be defined only by the following claims and their equivalents.

Claims

1. A mixer, comprising: an outer tube; a nozzle communicating with the outer tube; an inner tube located inside the outer tube and having an inlet, the inner tube being operable to receive a hydrocarbon stream through the inlet and to convey the hydrocarbon stream along a flow path passing through the inner tube from the inlet to an outlet of the inner tube; a space between the inner tube and the outer tube, the outer tube being operable to receive a diluent stream through the nozzle and to convey the diluent stream through the space; at least one baffle coupled to the inner tube and extending from the inner tube towards the outer tube through at least a portion of the space, the at least one baffle being operable to generate a twisted diluent flow from the diluent stream; The mixer is configured such that the twisted diluent flow and the hydrocarbon stream are mixed downstream of the outlet of the inner tube, and the twisted diluent flow forms a boundary layer along the inner surface of the outer tube.

2. The mixer according to claim 1, wherein the inner tube is coaxially configured with respect to the outer tube, the length of the inner tube is shorter than the length of the outer tube, and the boundary layer is operable to prevent or minimize contact of the liquid in the hydrocarbon stream with the inner surface of the outer tube.

3. The mixer according to claim 1, wherein the at least one baffle is a plurality of spiral baffles extending around the inner tube, and the plurality of spiral baffles have an angle of 30 degrees to 45 degrees with respect to the flow axis passing through the inner tube.

4. The mixer according to claim 1, wherein the inner tube includes at least one twister plate operable to generate a twisted hydrocarbon flow from the hydrocarbon stream.

5. The mixer according to claim 1, wherein the at least one baffle is a spiral baffle on the outer surface of the inner tube.

6. The mixer according to claim 1, wherein the boundary layer is operable to prevent or minimize contact of the liquid in the hydrocarbon stream with the inner surface of the outer tube.

7. A mixer, comprising: an outer tube; An inner tube that is inside the outer tube and is coaxially configured with respect to the outer tube, has an inlet, receives a hydrocarbon stream through the inlet, and is operable to convey the hydrocarbon stream along a flow path that passes through the inner tube from the inlet to the outlet of the inner tube, wherein the outlet of the inner tube is disposed inside the outer tube, the inner tube; A space between the inner tube and the outer tube, wherein the outer tube is operable to receive a diluent stream and convey the diluent stream through the space, including the space; A mixer in which the diluent stream and the hydrocarbon stream are mixed downstream of the outlet of the inner tube, and the diluent stream forms a boundary layer along the inner surface of the outer tube to prevent liquid or droplets from the hydrocarbon stream from contacting the inner surface of the outer tube.

8. Further comprising at least one baffle coupled to the inner tube and extending from the inner tube toward the outer tube through at least a portion of the space and operable to generate a twisted diluent flow from the diluent stream; The mixer according to claim 7, wherein the twisted diluent flow forms the boundary layer.

9. The mixer according to claim 8, wherein the at least one baffle is a plurality of spiral baffles extending around the inner tube, and the plurality of spiral baffles have an angle of 30 degrees to 45 degrees (including 30 degrees and 45 degrees) with respect to the flow axis passing through the inner tube.

10. The mixer according to claim 8, wherein the inner tube includes at least one twister plate operable to generate a twisted hydrocarbon flow from the hydrocarbon stream.

11. The mixer according to claim 10, wherein the rotation direction of the twisted diluent flow is the same as the rotation direction of the twisted hydrocarbon flow.

12. The mixer according to claim 10, wherein the rotation direction of the twisted diluent flow is opposite to the rotation direction of the twisted hydrocarbon flow.

13. The mixer according to claim 7, wherein the inner tube includes at least one twister plate operable to generate a twisted hydrocarbon flow from the hydrocarbon stream.

14. A mixer, An outer tube, An inner tube configured within the outer tube, which is operable to receive a hydrocarbon stream and convey the hydrocarbon stream through the inner tube, and the inner tube; A space between the inner tube and the outer tube, wherein the outer tube is operable to receive a diluent stream and convey the diluent stream through the space, and the space; A mixer in which the diluent stream and the hydrocarbon stream are mixed downstream of the outlet of the inner tube, and the diluent stream is configured to form a boundary layer along the inner surface of the outer tube to prevent or minimize contact of liquid or droplets from the hydrocarbon stream with the inner surface of the outer tube.

15. The mixer according to claim 14, wherein the inner tube includes at least one baffle on an outer surface of the inner tube, and the at least one baffle is operable to generate a swirling diluent flow that forms the boundary layer from the diluent stream.

16. The mixer according to claim 15, wherein the at least one baffle is configured on the outer surface of the inner tube at an angle of 30 degrees to 45 degrees with respect to a flow axis passing through the inner tube.

17. The mixer according to claim 14, wherein the inner tube includes at least one twister plate.

18. The mixer according to claim 14, including at least one twister plate inside the inner tube operable to generate a swirling hydrocarbon flow and at least one baffle outside the inner tube operable to generate a swirling diluent flow that forms the boundary layer.

19. The mixer according to claim 14, wherein the inner tube is configured coaxially with the outer tube.

20. The mixer according to claim 14, wherein a part of the length of the inner tube is accommodated within the outer tube, and the inner tube further includes a flow control device that is at least one baffle or at least one twister plate, and the flow control device extends along less than the whole of the part of the length of the inner tube.

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