The present invention is directed to a sampling device for acquiring a material sample. More particularly, the present invention is directed to an extendable sample capture element for use in a sampling device designed to extract samples such as, without limitation, reaction/reactant samples, from vessels such as reactor vessels.
As would be obvious to one of skill in the art, there are a number of situations and/or processes for which it would be desirable to extract a sample of a material from a vessel in which the material is contained. Such extraction would generally be desirable for purposes of examination or testing, but could be performed for other reasons, as well.
With respect to process monitoring, such sample extraction may be desirable in a number of processes, including without limitation, parallel synthesis (combinatorial chemistry) applications, organic synthesis, chemical process development, and the scale-up of laboratory processes into production. A number of other such applications wherein sample extraction would be of interest also exist and would be known to those of skill in the art.
Known sampling devices typically must be operated by hand, or require the use of a vacuum-based device mounted remotely or in a vessel containing a material of interest, or a by-pass port or similar mechanism through which amount of a material of interest can be siphoned. In either case, an extracted sample is generally removed from the vessel and then transferred to another container before the sample can be quenched or similarly operated upon.
Known hand-operated devices commonly suffer from a lack of precision with regard to the timing of sample capture and subsequent sample manipulation and, obviously, are typically not amenable to process automation. Further, known hand-operated devices can only be operated to take samples that are at atmospheric pressure. Reactions that take place under pressure cannot be sampled with such hand operated devices. A by-pass type of sampling device, where the reaction flows through a loop to a point where it can be sampled, can be used to sample reactions under pressure—however, a large reaction volume is required to use such a device.
Known automated devices do not permit quenching, dilution, etc., to take place substantially contemporaneously with sample capture but, rather, require that a sample be first transferred to another vessel. Consequently, the state of a given sample may actually change from the time of sample extraction to the time of quenching, etc.
Therefore, based on these foregoing issues with known sampling devices, it should be apparent that an in situ sampling device capable of accurately and repeatably capturing a material sample of known volume and of quenching or otherwise processing a sample substantially contemporaneously with sample capture have been developed. These devices and their methods of use are described in U.S. patent application Ser. Nos. 12/823,655 and 12/823,718, both filed on Jun. 25, 2010.
Embodiments of sampling devices as described in these aforementioned applications may be disposed as elongate probes having extendable sample capture elements. Among other things, a sampling device of the present invention may be used to capture small sample volumes (e.g., 5-100 μl), and to extract a sample from within a reaction volume. Because such a sampling device is a sealed unit, it can also be placed through a port into a pressurized or evacuated reaction chamber to sample a pressurized reaction volume. Such a sampling device may also be used throughout a wide temperature range (e.g., −40° C.-150° C.).
In one exemplary embodiment of such a sampling device, the device is configured as a substantially cylindrical and hollow outer tube of some length. A proximal end of the outer tube may be clamped or otherwise affixed to a body portion of a probe actuator assembly. Concentrically arranged within the outer tube at a distal end thereof is an assembly including an outer sleeve, an inner sleeve and an extendable sample capture element. A substantially frustoconical adapter is attached to the distal end of the outer tube and tapers to a reduced diameter that approximates the diameter of the outer sleeve.
A sample capture element is located to reciprocate within the inner sleeve. The outer diameter of the sample capture element is provided to be close in dimension to the inner diameter of the inner sleeve, such that a tight but slidable fit is produced therebetween. When the sample capture element is in a retracted (closed) position, the distal end thereof may be positioned substantially even with the distal ends of the inner porting sleeve and the outer sleeve. When the sample capture element is in an extended (sampling) position, the distal end thereof may protrude from the distal end of the outer sleeve. The sample capture element is provided with at least one sample capture pocket that, during sample capture element extension, is exposed to and captures an amount of a sample of interest.
The sample capture element is ported to allow for purging/venting and to allow for the in situ processing (mixing, dilution, quenching, etc.), of material samples while located in the sample capture pocket(s) thereof. Particularly, each sample capture pocket is provided with a supply port and a purge/vent port, each of which is associated with a corresponding channel that runs through the sample capture element and exits through the proximal end thereof. Sample lines (e.g., tubing) may be connected to each of these supply and purge/vent channels to lead processing materials to the sample capture pocket and to allow for venting and for material to be purged from the sample capture pocket.
In another exemplary embodiment, the above-described design may be altered to have a fewer number of individual components. Particularly, in this alternative embodiment, the inner and outer sleeves and the adapter of the previously described embodiment are combined into a single element. This element forms an end cap that threads into the distal end of an outer tube and acts as a reciprocation guide and protective cover for the sample capture element. The end cap contains interior channels or grooves that connect the ports of the sample capture pocket of the sample capture element to the channels of the sample capture element.
During use of either of these embodiments, the distal end of the device is typically immersed in or held near the surface of a material from which a sample is to be extracted. At the desired time, the sample capture element is extended into the material, whereby an amount of the material fills the sample capture pocket(s) and remains therein as the sample capture element is subsequently retracted back into the closed position. With the sample of material trapped in the sample capture pocket(s), the sample may be processed, such as by contacting the sample with a quenching or diluting substance so as to halt an ongoing reaction or dilute the sample, prior to transferring the sample of material to another device or vessel.
Sample capture elements of the present invention may be used with such sampling devices to facilitate capture and processing of material samples of interest.
The present invention is directed to sample capture elements for use in sampling devices like those described in U.S. patent application Ser. Nos. 12/823,655 and 12/823,718. Such sample capture elements may typically be cylindrical in shape, although other cross-sectional shapes are also possible. The length of a sample capture element may vary depending on the length of other components of the sampling device.
In any event, a sample capture element of the present invention is designed to reciprocate within a body portion of an above-described sampling device. To that end, the outer surface (e.g., diameter) of the sample capture element is preferably of a dimension that produces a sealing but guided slidable fit with the sampling element within which it reciprocates.
A sample capture element of the present invention is provided with at least one concave sample capture pocket that, during sample capture element extension, is exposed to and captures an amount of a sample in which the distal end of the sampling device is immersed. The sample capture pocket(s) may be provided in different sizes to capture different sample volumes (aliquots). Similarly, the sample capture pocket(s) may be of various shapes to produce desired quenching, mixing, dilution and/or discharge (purge) characteristics.
The sample capture element is ported to allow for purging/venting and to allow for quenching of material samples located in the sample capture pocket(s) thereof. Particularly, a sample capture pocket of a sample capture element of the present invention is provided with a supply port and a purge/vent port, each of which is associated with a corresponding channel that runs through, or along the exterior of, the sample capture element, and exits through or along a proximal end thereof. The portion of the sampling device body within which the sample capture element reciprocates is adapted to allow the ports in the sample capture pocket(s) to communicate with the corresponding channels in the sample capture element during a quenching, dilution or purge cycle.
A sample capture element of the present invention may also be provided with a by-pass groove that is placed in fluid communication with transfer ports of the channels in the sample capture element to permit circulation of a quench media while the sample capture element is in an extended position. This allows sampling lines and the channels in the sample capture element to be filled with recirculating quench media such that quench media is available to immediately flow into the sample capture pocket(s) and mix with a captured sample upon retraction of the sample capture element.
Certain embodiments of a sample capture element of the present invention may have more than one sample capture pocket. When multiple sample capture pockets are present, the pockets may be of the same volume or of different volumes. When multiple sample capture pockets are present, the pockets may also have different functions—for example, one pocket may be a sample capture pocket and another pocket may function as a mixing pocket.
The porting of a sample capture pocket may be provided at a particular location and/or at a particular angle to optimize the quenching, dilution, mixing and/or discharge of a material sample located therein. The size, location and path of the corresponding channels in the associated sample capture element may be similarly designed to optimize one or more of such operations. A sample capture element of the present invention may be constructed of a material described in U.S. patent application Ser. Nos. 12/823,655 and 12/823,718, or of another material understood by one of skill in the art to be acceptable for such a purpose.
In addition to the features mentioned above, other aspects of the present invention will be readily apparent from the following descriptions of the drawings and exemplary embodiments, wherein like reference numerals across the several views refer to identical or equivalent features, and wherein:
a shows a portion of one exemplary embodiment of a sample capture element of the present invention, wherein the sample capture element includes a sample capture pocket of semi-spherical shape;
b depicts the portion of the sample capture element of
a shows a portion of another exemplary embodiment of a sample capture element of the present invention, wherein the sample capture element includes a sample capture pocket of substantially the same volume as the pocket shown in
b depicts the portion of the sample capture element of
a-4b are two 3-dimensional rendered views of exemplary paths that may be formed by ports and associated channels used to provide material to and remove material from a sample capture element sample capture pocket;
a-5d show various views of the flow within a semi-spherical sample capture pocket with a front port of a particular angle and a rear port of a particular angle and slope, with the front port used as the inlet port;
a-6d show various views of the of the flow within the semi-spherical sample capture pocket of
a-7e show various views of the flow within another semi-spherical sample capture pocket with a front port of an angle different than that of the sample capture pocket of
a-8d show various views of the flow within the semi-spherical sample capture pocket of
a-9b are transparent views of a portion of an exemplary embodiment of a sample capture element of the present invention, wherein the sample capture element includes a pair of sample capture pockets of semi-spherical shape; and
One exemplary embodiment of a sample capture element 5 of the present invention is illustrated in
The sample capture element 5 is provided with a concave sample capture pocket 10 that, during sample capture element extension, is exposed to and captures an amount of a material in or over which the distal end of the associated sampling device is positioned. The sample capture pocket 10 may be provided in different sizes to capture different sample volumes (aliquots). In this particular embodiment, the sample capture pocket 10 is of semi-spherical shape. However, as demonstrated by
The sample capture element 5 is ported to allow for the quenching, dilution and discharge of material samples located in the sample capture pocket 10 thereof, and to allow for purging and venting. Particularly, the sample capture pocket 10 is provided with a first port 15 and a second port 20 for these purposes. The first port 15 may be an inlet port for supplying dilution, quench and purging materials to the sample capture pocket 10, and the second port 20 may be an outlet port for the discharge of a material sample and for purging and other materials supplied to the sample capture pocket. The role of the first port 15 and the second port 20 may also be reversed. As explained in more detail below, the angle (e.g., swirl angle) and axial slope of the ports 15, 20 may vary.
Each of the first port 15 and second port 20 is associated with a corresponding channel 25, 30 that extends along the sample capture element 5 and exits along the proximal end 5a thereof. In this particular embodiment, the channels 25, 30 run through the sample capture element 5. In other embodiments, such channels may be cut into the exterior of a sample capture element.
As represented in
The channels 25, 30 connect the sample capture pocket 10 to sampling lines (not shown), which may be tubing or similar conduit. One of the sampling lines may be connected to sources of quench, dilution and purging materials, while another sampling line may direct used purging material to a waste location or a discharged material sample to an analyzer or another downstream location.
The sample capture element 5 may also be provided with a by-pass groove 45 that is placed in fluid communication with the channels 25, 30 in the sample capture element by the porting slots 35, 40 in the sampling body to permit circulation of a quench media while the sample capture element is in an extended position. This allows sampling lines and the channels 25, 30 in the sample capture element 5 to be pre-filled with recirculating quench media. Consequently, quench media is available to immediately flow into the sample capture pocket 10 and mix with a captured sample upon retraction of the sample capture element.
An alternate embodiment of a sample capture element 50 of the present invention is depicted in
The sample capture element 50 is also provided with ports 60, 65 for the purposes described above with respect to the embodiment of
As with the sample capture element 5 of
The length of a sample capture element of the present invention may vary depending on the length of other components of the sampling device to which the sample capture element is installed. Preferably, but not essentially, the length of the sample capture element is such that when the sample capture element is in a retracted (closed) position, the distal end thereof is positioned substantially evenly with a distal end of the sampling device body. When the sample capture element is in an extended (sampling) position, the distal end thereof protrudes from the distal end of the sampling device body by some predetermined distance. In any event, the proximal end of the sample capture element resides in the interior of the sampling device body, whether the sample capture element is in an extended or retracted position.
A sample capture element of the present invention may be constructed from various materials depending on the substances to which it might be exposed. For example, a sample capture element of the present invention may be constructed of a metallic material (e.g., HASTELLOY), a ceramic material or a glass material.
It has been determined that the optimal shape of the sample capture pocket of a given sample capture element may be influenced by a number of factors. These factors may include, without limitation: desired sample volume; proper sample capture; sealing with a surrounding sampling device element; load on the pocket area of the sample capture element during actuation; ease of pocket manufacture; the ability to achieve an acceptable surface finish during manufacturing; proper bubble (e.g., purge gas bubble) release upon sample capture element extension; port position for manufacturability; and port position for effective bidirectional flow.
As would likely be apparent to one of skill in the art, employing a sample capture pocket shape that facilitates manufacturing also generally improves the ability to achieve a good surface finish without the need for secondary operations. A simple sample capture pocket geometry may also be simpler to measure and verify.
As mentioned above, another consideration in designing a sample capture pocket is proper bubble release. Such a bubble will commonly form in the sample capture pocket when purging is accomplished with a gaseous purging material, the bubble being subsequently released from the sample capture pocket upon the next subsequent extension of the associated sample capture element. Typically, the gas bubble is released into a material of interest when the sample capture element is extended therein to acquire a material sample. In this regard, it has been discovered that gas bubble release is improved by employing a shallow sample capture pocket having shallow sides.
The position of the inlet and outlet ports of a sample capture pocket is ideally defined by optimizing the flow of liquid through the sample capture pocket during sample acquisition. Because the intended roles of the inlet and outlet ports of a given sample capture element may be reversed in use, the flow through the associated sample capture pocket should be effective in removing (discharging) a captured sample in either flow direction.
To this end, experimentation with various sample capture pocket shapes, port locations, and port angles has been conducted. Two sample capture pocket shapes that were tested include the semi-spherical and frustoconical pocket shapes shown in
The frustoconical pocket allowed for more extreme rear port positions to be tested and evaluated. It was determined from this testing that flow scavenging could be improved, as the conical shape appears to interfere with material flow through the sample capture pocket, thereby producing areas of low flow.
While of equal volume, the semi-spherical sample capture pocket of
During testing, it was determined that offsetting the front port created a strong scavenging swirl within the sample capture pocket when the front port was used as the inlet port. It was similarly determined that offsetting the rear port created a strong scavenging swirl within the sample capture pocket when the rear port was used as the inlet port. Further, it was found that the rear port entrance into the sample capture pocket needs to be below the lip of the sample capture pocket in order to avoid direct coupling. As used herein, “direct coupling” refers to a flow that does not produce a swirling effect within a sample capture pocket. More particularly, especially with respect to viscous material samples, it was determined that the inflow into a sample capture pocket could possibly punch a hole through the material and establish a direct flow between the inlet and outlet ports without producing a swirling of the material. The above-described location of the rear port entrance into the sample capture pocket helps to ensure that direct coupling does not occur.
The aforementioned realizations were developed by running a number of different flow visualizations on various sample capture pocket and port designs. Several such exemplary flow visualizations produced using SOLIDWORKS FloXpress appear in
In the flow visualizations of
In the flow visualizations of
When a sample capture element of the present invention is extended, the sample capture pocket thereof may be oriented in any direction with a material sample (e.g., reaction mixture). This allows the user to, for example, take advantage of the circulation of the material typically caused by stirring.
The fit of a sample capture element within its surrounding sleeve is such as to permit axial reciprocation of the sample capture element while simultaneously providing a seal capable of resisting internal pressures generated during, for example, quenching, purging and cleaning. The seal formed between the sample capture element and its surrounding sleeve should also be sufficient to prevent an intrusion of sample material caused by the external pressures that may exist within a sample reaction chamber or other vessel—whether the sample capture element is in an extended or retracted position.
The detailed design of the sample capture pocket lip minimizes or eliminates excessive wear of the sleeve that could be caused by repeated extension/retraction of the sample capture element. Additionally, upon retraction after sample capture, the sample capture element is wiped by the sleeve.
Several conclusions can be drawn from the conducted experimentation and the exemplary flow visualizations. These conclusions include, for example, that a spherical sample capture pocket improves the transfer of a captured sample and appears to produce a more desirable flow pattern in either direction. A spherical sample capture pocket also appears to produce a faster and more complete mixing and lower sample dilution values, and also allows the flow to be established around the largest dimension—the lip interface between the outer sealing sleeve and the sample capture element. The type of swirling flow produced within a spherical sample capture pocket is beneficial especially as the sample viscosity increases, as it releases the acquired sample from the walls of the sample capture pocket. The circular scavenging flow produced by such a sample capture pocket has also been found to be desirable particularly when the sample is a slurry, because maintaining the slurry in suspension allows for complete quenching and evacuation of the sample. The use of a spherical sample capture pocket has also been found to reduce tailing (i.e., the gradual reduction in sample concentration (from peak to zero) as the acquired sample is removed from the sample capture pocket).
An alternate embodiment of a sample capture element 100 of the present invention is depicted in
Each of the sample capture pockets 105, 110 includes a port 120, 125 for providing fluid communication between the sample capture pockets and channels 130, 135 in or on the sample capture element 100. As shown in
The two pocket design of this sample capture element 100 may allow a larger sample volume to be captured (in comparison to a sample capture element with a single sample capture pocket) while maintaining the same bubble release geometry and basic dimensions of a given sample capture element. Alternatively, such a two pocket design may provide for substantially the same sample capture volume as a single sample capture pocket, but may employ two shallower sample capture pockets to facilitate the capture of sample materials that tend to have difficulty flowing into a pocket.
The sample capture pockets 105, 110 may be of the same or of different dimensions and volumes. The connecting port 115 between the two sample capture pockets 105, 110 functions in a similar manner to the port 20 of
In the embodiment of
The flow of quench material may then be reversed, such that sample and quench materials are drawn back through the sample capture pockets, which creates additional mixing. This cyclic flow pattern may be performed several times to achieve a fully quenched sample, which is then expelled through one of the porting slots and associated channels, and through a connected sample line to a downstream location (e.g., a sample vial, analysis system, etc.).
In the particular sample capture element 100 of
An alternative embodiment of a sample capture element 200 of the present invention is depicted in
The two pocket design of this sample capture element 200 allows the lower pocket to be used as a sample capture pocket 210 and the upper pocket to be used as a mixing pocket 205 within which a sample of material may be mixed with a quench medium, a dilution material, etc. Consequently, material samples will be trapped in the lower sample capture pocket 210, whereafter the material sample may be transferred in whole or part to the upper mixing pocket 205 for quenching or dilution prior to discharge to an analyzer or other downstream location.
To this end, the mixing pocket 205 includes an inlet port 220, while the sample capture pocket 210 includes an inlet port 225 for receiving non-sample materials and an outlet port 230 for providing fluid communication with the mixing pocket and between channels 235, 240 in or on the sample capture element 200. In this embodiment, an inlet port 225 of the sample capture pocket 210 connects the sample capture pocket to a corresponding sample capture element channel 240 via a porting slot 245 in the element 150 of the sampling device in which the sample capture element reciprocates. The outlet port 230 of the sample capture pocket 210 connects the sample capture pocket to the mixing pocket 205 via a second porting slot 250 and the mixing pocket inlet port 220 located in the surrounding element 150 of the sampling device. Particularly, the inlet port 220 of the mixing pocket 205 is connected to the second porting slot 250, and the mixing pocket is also connected to a corresponding channel 235 in the sample capture element 200.
As an example of a quenching operation involving such a sample capture element 150, the mixing pocket 205 may be supplied with quench media while the sample capture element 200 is extended to capture a material sample of interest in the sample capture pocket 210. After sample capture element retraction, quench material may be supplied to the sample capture pocket 210 via its inlet port 225. The flow of quench material into the sample capture pocket 210 quenches some of the sample located therein and displaces some of the sample through the outlet port 230 and into the mixing pocket 205, which is already charged with quench media. Thus, quenching mixing is now occurring at both ends of the acquired sample, which hastens the quenching process.
The flow of quench material may then be reversed, such that sample and quench materials are drawn back through the sample capture and mixing pockets, which creates additional mixing. As described above, this cyclic flow pattern may be performed several times to achieve a fully quenched sample, which is subsequently expelled from the mixing pocket 205, through the channel 235, and through a connected sample line to a downstream location (e.g., a sample vial, analysis system, etc.). Such a cyclic flow process may additionally assist in placing slurries into suspension.
As shown in
While certain embodiments of the present invention are described in detail above, the scope of the invention is not to be considered limited by such disclosure, and modifications are possible without departing from the spirit of the invention as evidenced by the following claims: