The present disclosure relates to catalyst carriers. More particularly, the present disclosure relates to particular structural designs for catalyst carriers.
Catalyst carriers may be used in a wide variety of applications and, in particular, the structural design of catalyst carriers is directly connected to their performance during a catalytic process. Generally, a catalyst carrier needs to possess, in combination, at least a minimum surface area on which a catalytic component may be deposited, known as a geometric surface area (GSA), high water absorption and crush strength. In addition, catalytic processes may include packing multiple catalyst carriers in a reactor tube where the general structure of the carriers affects the packing ability of the particles and thus the flow of fluid through the reactor tube. In such reactor tubes, geometric size and shape of the carrier, including GSA, must be balanced with the resistance to fluid flow caused by the packing of the catalytic particles, a performance parameter known as pressure drop and other parameters, such as, piece count. In catalyst carrier design, an increase in certain structural characteristics, such as GSA, due to alterations to known catalyst carrier shapes generally means reduction in catalyst carrier performance when packed in a reactor tube, for example, increased pressure drop or a reduction in the number of catalyst carriers that may be packed into the reaction tube (i.e., piece count). Maintaining the necessary balance between GSA and desired performance parameters of a catalyst carrier is achieved by extensive experimentation making the catalyst carrier art even more unpredictable than other chemical process art. Accordingly, the industry continues to demand improved catalyst carrier designs that maximize desired carrier characteristics while maintaining suitable performance standards.
According to one aspect of the invention, a catalyst carrier may have a cross-sectional shape that may include a plurality of surface channels having a first channel width and a second channel width, where the first channel width may be closer to a periphery of the cross-sectional shape than the second channel width and the first channel width may be less than the second channel width. The cross-sectional shape may further include a plurality of surface features where at least one surface feature is located between at least one pair of surface channels. The cross-sectional shape may further include a ratio LOC/LSCP of at least about 1.7, where LOC is a length of a total contour of the cross-sectional shape and LSCP is a length of an outer simple convex perimeter of the cross-sectional shape.
According to yet another aspect of the invention, a catalyst carrier may have a cross-sectional shape that may include a plurality of surface channels having a first channel width and a second channel width, where the first channel width may be closer to a periphery of the cross-sectional shape than the second channel width and the first channel width may be less than the second channel width. The cross-sectional shape may further include a plurality of surface features where at least one surface feature is located between at least one pair of surface channels. The cross-sectional shape may further include a ratio GSA/dP of at least about 0.62 (m2/m3)/(Pa/m), where GSA is a geometric surface area of the catalyst carrier and dP is a pressure drop of the catalyst carrier as measured at a mass flow of 2440 kg/m2*hr (500 lbs/ft2*hr).
According to still another embodiment, a catalyst carrier may have a cross-sectional shape that may include a plurality of surface channels having a first channel width and a second channel width, where the first channel width may be closer to a periphery of the cross-sectional shape than the second channel width and the first channel width may be less than the second channel width. The cross-sectional shape may further include a plurality of surface features where at least one surface feature is located between at least one pair of surface channels. The cross-sectional shape may further include a ratio GSA/PC1/3 of at least about 5.9, where GSA is a geometric surface area (m2/m3) of the catalyst carrier and PC is a calculated piece count measured in (pieces per m3).
The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
The use of the same reference symbols in different drawings indicates similar or identical items.
As used herein, the terms “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 that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such process, method, article, or apparatus.
As used herein, and unless expressly stated to the contrary, “or” refers to an inclusive- or and not to an exclusive- or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
Also, the use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
It will be appreciated that the terms “catalyst carrier” or “catalyst carriers” as used herein may refer to uncoated catalyst carriers or catalyst carriers coated with a catalyst. It will be further appreciated that whether the catalyst carrier is uncoated or coated, does not change the fundamental characteristics of the carrier as described herein.
A catalyst carrier having a particular structure is described herein. For purposes of illustration,
According to a particular embodiment, a surface channel 122 may be defined as any portion of the cross-sectional shape 110 having a contour creating a partially enclosed space that opens to a periphery of the cross-sectional shape 110. The surface channel 122 may have a varying width, referred to herein as a varying channel width. The varying channel width of the surface channels 122 may include at least a first channel width 130 and a second channel width 135, where the first channel width 130 is located closer to the periphery of the cross-sectional shape 110 than the second channel width 135 and where the first channel width 130 is less than the second channel width 135, creating the partially enclosed space of the surface channels 122. It will be appreciated that if a surface channel 122 includes a first channel width 130 and a second channel width 135, it does not mean that the widths of the channel are constant. Rather, the first and second channel widths may be particular measurements at particular locations of the surface channel 122.
An external surface feature 124 in the cross-sectional shape 110 may be defined as any variation or deviation in the contour of the cross-sectional shape 110 from a smooth or generally smooth arcuate or flat contour that is outside of or not included as part of the contour of the surface channel 122. According to particular embodiments, an external surface feature 124 may have an outward facing orientation indicating that the feature deviates outward from a smooth or generally smooth arcuate or flat shape as illustrated by external surface feature 124a or an external surface feature 124 may have an inward facing orientation indicating that the feature deviates inward from a smooth or generally smooth arcuate or flat shape as illustrated by external surface feature 124b. It will be appreciated that an external surface feature 124 may be described as having any desirable geometric shape. For example, according to certain embodiments, the external surface feature 124 may have a convex arcuate shape. According to still another embodiment, the external surface feature 124 may have a concave arcuate shape. According to yet another embodiment, the external surface feature 124 may have a concave triangular shape. According to still another embodiment, the external surface feature 124 may have a convex triangular shape.
According to particular embodiments, a cross-sectional shape 110, as shown in
According to still another embodiment, a cross-sectional shape 110 may have a particular number of external surface features 124 located between adjacent surface channels 122. For example, a cross-sectional shape 110 may include at least one external surface feature 124 between adjacent surface channels 122, such as, at least two external surface features 124 between adjacent surface channels 122, at least three external surface features 124 between adjacent surface channels 122, at least four external surface features 124 between adjacent surface channels 122, at least five external surface features 124 between adjacent surface channels 122, at least six external surface features 124 between adjacent surface channels 122, at least seven external surface features 124 between adjacent surface channels 122, at least eight external surface features 124 between adjacent surface channels 122, at least nine external surface features 124 between adjacent surface channels 122 or even at least ten external surface features 124 between adjacent surface channels 122.
Referring back to
According to still another embodiment, external surface features 124 located between adjacent surface channels 122 may be combined to define lobe 126. According to certain embodiments a lobe 126 may be a multi-sected tip lobe indicating that the lobe includes at least 2 distinct tips. According to still another embodiment, a lobe 126 may include at least about 3 tips, such as, at least about 4 tips or even at least about 5 tips.
According to yet another particular embodiment, a cross-sectional shape may have a particular number of internal surface features. An internal surface feature in a cross-sectional shape may be defined as any variation or deviation in the contour of the cross-sectional shape from a smooth or generally smooth arcuate or flat contour that is inside of or included as part of the contour of a surface channel.
According to certain embodiments, referring back to
According to still other embodiments, a catalyst carrier may have a particular geometric surface area GSA. The geometric surface area of a catalyst carrier of a particular nominal shape and size is the standardized GSA typically expressed as square meters per cubic meters (m2/m3). The GSA of the catalyst carrier is determined by measuring the average surface area of a single catalyst carrier having average dimensions of a batch of catalyst carriers, then calculating the piece count of the batch of catalyst carriers and multiplying the surface area of the single catalyst carrier by the piece count. To measure the GSA of the single average catalyst carrier having a shape with two equivalent parallel end-faces, the area of the end faces are determined using an image analysis technique in which the dimensions along all the inner and outer contours along a cross-section or end face are measured. The image analysis technique results in the determination of the end face area and also the total perimeter. Next, the surface area along the length of the single average catalyst carrier is determined by measuring the average length of the single average catalyst carrier with calipers and multiplying the average length by the total perimeter of the average catalyst carrier. This surface area along the length is added to 2 times the end face area to obtain the total geometric surface area of the single average catalyst carrier. The piece weight of the catalyst carrier is determined by taking at least 100 pieces of the catalyst carrier, each having dimensions representative of the nominal, weighing them as a group, and dividing by the exact number of pieces. The packing density of the nominal carrier of the specific material of construction is measured using a calibrated cylinder with a diameter at least 10 times the diameter of the longest dimension of the shape being measured. It is preferred that the cylinder have a calibrated volume (V) of at least 1000 ml or 1/16 ft3. It is also preferred that the cylinder be made from stainless steel. Using a scoop, the cylinder is filled approximately half full, and then placed on a metal plate and raised 12.7 mm (0.5 inches) and allowed to drop. The dropping is repeated a total of ten times. Then, using the scoop, the cylinder is filled to the top and is raised 12.7 trim and allowed to drop, repeating for a total of ten times. Additional media is added to fill the cylinder to overflowing, and a metal straight edge is used to level the top surface. The content of the cylinder is weighed to 0.1 g. The packing density is calculated as the weight divided by the cylinder volume, typically expressed as kg/m3, g/cc or lbs/ft3. Once the single average piece GSA, the average piece weight, and the average packing density are determined, the piece count is then determined by multiplying the packing density in kg/m3 by 1000 and dividing by the piece weight in grams per piece to obtain pieces per m3. The piece count (pc/m3) can then be multiplied by the GSA of the single average catalyst carrier (m2/pc) to obtain the standardized GSA (m2/m3).
Referring back to
According to still another embodiment, a catalyst carrier may have a particular pressure drop as measured at a mass flow of 2440 kg/m2*hr (500 lbs/ft2*hr). The pressure drop of a catalyst carrier is the difference in pressure between two points in a fluid carrying system as measured using airflow through a packed bed of catalyst carriers. Initial air pressure is measured at an air inlet point prior to air passing through the packed bed and final air pressure is measured at an air outlet point after air passes through the packed bed. Accordingly, the pressure drop is equal to the difference between the initial air pressure and the final air pressure. For purposes of embodiments described herein, the pressure drop is measured in a vertical column having a diameter of 50 mm and packed media height of 1219.2 mm. The media is poured in to a height of about 610 mm and then the tube is vibrated for 5 seconds. Then, the tube is filled to a height of about 915 mm and vibrated for another 5 seconds. The tube is then filled to a height of about 1.219 mm and vibrated for another 5 seconds. After the final vibration, additional media is added to reach the full 1219.2 mm packed height. The unit is sealed and the blower is run at 5 different airflow settings, allowing 3 to 5 minutes at each setting for stabilization. At each air flow setting, ranging from about 0.3 to 1.1 m per sec, equating to a mass velocity of about 180 to 1110 lbs/ft2*hr (878 to 5417 kg/m2*hr), the manometer pressures are measured. A graph called the pressure drop curve is prepared by charting the pressure difference as a function of the mass velocity. The pressure drop of different types of media can be compared by overlaying the pressure drop curves. A simpler way to compare different media is to select a mid-range mass velocity (2440 kg/m2*hr) and compare at this point on the curves.
Again referring back to
According to yet another embodiment, a catalyst carrier may have a particular ratio GSA/dP, where GSA is the geometric surface area of the catalyst carrier and dP is the pressure drop of the catalyst carrier as measured at a mass flow of 2440 kg/m2*hr (500 lbs/ft2*hr). Again referring back to
According to still another embodiment, a catalyst carrier may include a particular piece count. As previously noted herein, the piece count of a catalyst carrier (pieces per m3) is calculated by multiplying the packing density of the catalyst carrier in kg/m3 units by 1000 to convert from kg to g and then dividing by the calculated average piece weight of the catalyst carrier in g/piece.
Again referring back to
According to still another embodiment, a catalyst carrier may include a particular ratio GSA/PC1/3. Again referring back to
According to still another embodiment, a catalyst carrier may include a particular packing density. As previously noted herein, the packing density of the nominal carrier of the specific material of construction is measured using a calibrated cylinder with a diameter at least 10 times the diameter of the longest dimension of the shape being measured. It is preferred that the cylinder have a calibrated volume (V) of at least 1000 ml or 1/16 ft3. It is also preferred that the cylinder be made from stainless steel. Using a scoop, the cylinder is filled approximately half full, and then placed on a metal plate and raised 12.7 mm (0.5 inches) and allowed to drop. The dropping is repeated a total of ten times. Then, using the scoop, the cylinder is filled to the top and is raised 12.7 mm and allowed to drop, repeating for a total of ten times. Additional media is added to fill the cylinder to overflowing, and a metal straight edge is used to level the top surface. The content of the cylinder is weighed to 0.1 g. The packing density is calculated as the weight divided by the cylinder volume, typically expressed as kg/m3, g/cc or lb/ft3.
Again referring back to
According to yet another embodiment, a cross-sectional shape of a catalyst carrier may have a particular outer contour total length LOC. Again referring back to
According to yet another embodiment, a cross-sectional shape of a catalyst carrier may have a particular outer simple convex perimeter total length LSCP. Again referring back to
Again referring back to
According to certain embodiments, a cross-sectional shape may include a particular ratio DMMAX/DMMIN. Again referring back to
According to certain embodiments, a cross-sectional shape may include maximum diameter DMMAX. Again referring back to
According to certain embodiments, a cross-sectional shape may include a minimum diameter DMMIN. Again referring back to
According to still other embodiment, a catalyst carrier having a cross-sectional shape as described herein may have a particular crush strength (CS). Crush strength is calculated based on ASTM D-4179 (2011). For example, a catalyst carrier may have a crush strength of at least about 10 lbs.
According to still another embodiment, a catalyst carrier having a cross-sectional shape as described herein may further include a particular 3-dimensional shape. For example, the 3-dimensional shape of the catalyst carrier may be generally spherical, meaning that the catalyst carrier may fit within a best-fit sphere while occupying a majority of an interior volume of the best-fit sphere. For example, the catalyst carrier having a generally, spherical shape may occupy at least about 75% of an interior volume of the best-fit sphere, at least about 80% of an interior volume of the best-fit sphere, at least about 85% of an interior volume of the best-fit sphere, at least about 90% of an interior volume of the best-fit sphere, such as, at least about 92% an interior volume of the best-fit sphere, at least about 95% an interior volume of the best-fit sphere, at least about 97% an interior volume of the best-fit sphere or even 99% an interior volume of the best-fit sphere.
According to still another embodiment, a catalyst carrier having a cross-sectional shape as described herein may generally ellipsoidal, meaning that the catalyst carrier may fit within a best-tit ellipsoid while occupying a majority of an interior volume of the best-fit ellipsoid. For example, the catalyst carrier having a generally ellipsoidal shape may occupy at least about 75% of an interior volume of the best-fit ellipsoid, at least about 80% of an interior volume of the best-fit ellipsoid, at least about 85% of an interior volume of the best-fit ellipsoid, at least about 90% of an interior volume of the best-fit ellipsoid, such as, at least about 92% an interior volume of the best-fit ellipsoid, at least about 95% an interior volume of the best-fit ellipsoid, at least about 97% an interior volume of the best-fit ellipsoid or even 99% an interior volume of the best-fit ellipsoid. According to still another embodiment, the cross-sectional shape as described herein may be perpendicular to a longitudinal axis running through a center-point of and along a full length of the best-fit ellipsoid. According to still another embodiment, the cross-sectional shape may include the center point of the best-fit ellipsoid.
According to still another embodiment, a catalyst carrier having a cross-sectional shape as described herein may be generally cylindrical, meaning that the catalyst carrier may fit within a best-fit cylinder while occupying a majority of an interior volume of the best-fit cylinder. For example, the catalyst carrier having a generally cylindrical shape may occupy at least about 75% of an interior volume of the best-fit cylinder, at least about 80% of an interior volume of the best-fit cylinder, at least about 85% of an interior volume of the best-fit cylinder, at least about 90% of an interior volume of the best-fit cylinder, such as, at least about 92% an interior volume of the best-fit cylinder, at least about 95% an interior volume of the best-fit cylinder, at least about 97% an interior volume of the best-fit cylinder or even 99% an interior volume of the best-fit cylinder. According to still another embodiment, the cross-sectional shape as described herein may be perpendicular to a longitudinal axis running through a center-point of and along a full length of the best-fit cylinder. According to still another embodiment, the cross-sectional shape may include the center point of the best-fit cylinder.
According to yet another embodiment, a catalyst carrier having a cross-sectional shape as described herein may be formed using any desirable forming technique capable of producing the catalyst carrier at a constant size and shape. According to still another embodiment, a catalyst carrier having a cross-sectional shape as described herein may be formed using a high speed forming process. For example, a catalyst carrier having a cross-sectional shape as described herein may be formed using an extrusion method. According to yet another embodiment, a catalyst carrier having a cross-sectional shape as described herein may be formed using a pressing method. According to still another embodiment, a catalyst carrier having a cross-sectional shape as described herein may be formed using a molding method.
Many different aspects and embodiments are possible. Some of these aspects and embodiments are described below. After reading this specification, those skilled in the art will appreciate that these aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the items as listed below.
Item 1. A catalyst carrier having a cross-sectional shape comprising: a plurality of surface channels, each surface channel having a first channel width and a second channel width, wherein the first channel width is closer to a periphery of the cross-sectional shape than the second channel width and wherein the first channel width is less than the second channel width; a plurality of surface features, wherein at least one surface feature is located between at least one pair of adjacent surface channels; and a ratio LOC/LSCP of at least about 1.7, where LOC is a length of a total contour of the cross-sectional shape and LSCP is a length of an outer simple convex perimeter of the cross-sectional shape.
Item 2. A catalyst carrier having a cross-sectional shape comprising: a plurality of surface channels, each surface channel having a first channel width and a second channel width, wherein the first channel width is closer to a periphery of the cross-sectional shape than the second channel width and wherein the first channel width is less than the second channel width; a plurality of surface features, wherein at least one surface feature is located between at least one pair of adjacent surface channels; and wherein the catalyst carrier comprises a ratio GSA/dP of at least about 0.62 (m2/m3)/(Pa/m), where GSA is a geometric surface area of the catalyst carrier and dP is a pressure drop of the catalyst carrier as measured at a mass flow of 2440 kg/m2*hr (500 lbs/ft2*hr).
Item 3. A catalyst carrier comprising a cross-sectional shape comprising: a plurality of surface channels, each surface channel having a first channel width and a second channel width, wherein the first channel width is closer to a periphery of the cross-sectional shape than the second channel width and wherein the first channel width is less than the second channel width; a plurality of surface features, wherein at least one surface feature is located between at least one pair of adjacent surface channels; and wherein the catalyst carrier comprises a ratio GSA/PC1/3 of at least about 5.9, where GSA is a geometric surface area (m2/m3) of the catalyst carrier and PC is a calculated piece count (pieces per m3).
Item 4. The catalyst carrier of any one of items 2 and 3, wherein the cross-sectional shape further comprises a ratio LOC/LSCP of at least about 1.7 and not greater than about 2.8, wherein LOC is a length of a total contour of the cross-sectional shape and LSCP is a length of an outer simple convex perimeter of the cross-sectional shape.
Item 5. The catalyst carrier of any one of items 1 and 3, wherein the catalyst carrier further comprises a ratio GSA/dP of at least about 0.62 (m2/m3)/(Pa/m) and not greater than about 0.98, where GSA is a geometric surface area of the catalyst carrier and dP is a pressure drop of the catalyst carrier as measured at a mass flow of 2440 kg/m2*hr (500 lbs/ft2*hr).
Item 6. The catalyst carrier of any one of items 1 and 2, wherein the catalyst carrier further comprises a ratio GSA/PC1/3 of at least about 5.9 and not greater than about 7.5, where GSA is the geometric surface area of the catalyst carrier and PC is a calculated piece count.
Item 7. The catalyst carrier of any one of items 1, 2 and 3, wherein the catalyst carrier further comprises a GSA at least about 700 m2/m3 and not greater than about 2000 m2/m3.
Item 8. The catalyst carrier of any one of items 1, 2 and 3, wherein the catalyst carrier further comprises a nominal piece size corresponding to a piece count (PC) of at least about 3,000,000 pc/m3 and not greater than about 13,000,000 pc/m3.
Item 9. The catalyst carrier of any one of items 1, 2 and 3, wherein the catalyst carrier further comprises a pressure drop (dP) of not greater than about 2600 Pa/m and at least about 900 Pa/m, as measured in a 50.8 mm diameter tube packed to a 4 foot height, in ambient air at a mass flow of 2440 Kg/m2*hr.
Item 10. The catalyst carrier of any one of items 1, 2 and 3, wherein the cross-sectional shape comprises a total contour length (LOC) of at least about 10 mm and not greater than about 50 mm.
Item 11. The catalyst carrier of any one of items 1, 2 and 3, wherein the cross-sectional shape comprises a length of the outer simple convex perimeter (LSCP) of at least about 5 mm and not greater than about 30 mm.
Item 12. The catalyst carrier of any one of items 1, 2 and 3, wherein the cross-sectional shape further comprises a plurality of lobes located between adjacent channels.
Item 13. The catalyst carrier of any one of items 12, wherein at least one of the plurality of lobes is a multisected tip lobe.
Item 14. The catalyst carrier of any one of items 13, wherein the multisected tip lobe comprises at least about 3 tips, at least about 4 tips, at least about 5 tips.
Item 15. The catalyst carrier of any one of items 13, wherein the plurality of lobes comprise an outer wall surface and wherein the outer wall surface comprises at least 2 changes in direction.
Item 16. The catalyst carrier of any one of items 1, 2 and 3, wherein the catalyst carrier comprises a crush strength (CS) of at least about 10 lbs.
Item 17. The catalyst carrier of any one of items 1, 2 and 3, wherein a 3-dimensional shape of the catalyst carrier is generally spherical.
Item 18. The catalyst carrier of any one of items 17, wherein the cross-sectional shape includes a center point of the generally spherical shape.
Item 19. The catalyst carrier of any one of items 2 and 3, wherein a 3-dimensional shape of the catalyst carrier is generally ellipsoidal.
Item 20. The catalyst carrier of any one of items 19, wherein the cross-sectional shape includes a center point of the generally ellipsoidal shape.
Item 21. The catalyst carrier of any one of items 19, wherein the cross-sectional shape is perpendicular to a longitudinal axis running a length of the generally ellipsoidal shape through a center point of the generally ellipsoidal shape.
Item 22. The catalyst carrier of any one of items 1, 2 and 3, wherein a 3-dimensional shape of the catalyst carrier is generally cylindrical.
Item 23. The catalyst carrier of any one of items 22, wherein the cross-sectional shape includes a center point of the generally cylindrical shape.
Item 24. The catalyst carrier of any one of items 22, wherein the cross-sectional shape is perpendicular to a longitudinal axis running a length of the generally cylindrical shape through a center point of the generally cylindrical shape.
The following includes a comparison between eight comparative catalyst carriers having distinct cross-sectional shapes and example catalyst carriers having cross-sectional shapes according to embodiments described herein.
Table 1 includes a summary of physical measurements of the cross-sectional shapes of Comparative Catalyst Carrier Examples C1-C8 and Catalyst Carrier Examples S1 and S2. Physical measurements include the length of the X-dimension for each example, the total contour of the cross-sectional shape (LOC) for each example, the length of outer simple convex perimeter (LSCP) for each example and the ratio LOC/LSCP for each example.
Table 2 includes a summary of certain physical characteristics and performance measurements of the Comparative Catalyst Carrier Examples C1-C8 and Catalyst Carrier Examples S1 and S2. The physical measurements include the geometric surface area (GSA) of each example. The performance measurements include the recorded piece count, pressure drop and crush strength of each example measured.
The Abstract of the Disclosure is provided to comply with Patent Law and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately, claimed subject matter.
This application is a divisional application of U.S. Ser. No. 15/278,074, filed Sep. 28, 2016, now abandoned, and claims the benefit of U.S. Provisional Application No. 62/241,788 filed Oct. 15, 2015.
Number | Date | Country | |
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62241788 | Oct 2015 | US |
Number | Date | Country | |
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Parent | 15278074 | Sep 2016 | US |
Child | 16220088 | US |