SMALL SCALE REACTOR

A small scale reactor includes a seal gate for closing an interior of a test cell in the reactor. The seal gate protects elastomeric seals in an injection port from the effluent from the test cell. A stirrer of the small scale reactor has a clip on magnet that allows for easy replacement. A drive system of the small scale reactor does not have to be disconnected when the test cells are opened to permit access for placing or retrieving the vials in the reactor.

FIELD OF INVENTION

This invention relates generally to small-scale laboratory reactors.

BACKGROUND OF THE INVENTION

It is known to provide small scale reactors with a feature that permits other substances, such as other chemical reactants, to be introduced into the test vial in the reactor. The individual test cells have a small opening to a surrounding environment that is closed by a valve. Typically, the valve is a duckbill valve arranged so that high pressure in the test cell acts to urge the valve closed. Moreover, the natural bias of the valve material also urges the valve to remain closed. A cannula can be inserted into the opening and push open the valve so that a substance passing through the cannula can be received in the test cell. When the cannula is removed, the duckbill valve closes behind the exiting cannula and re-seals the test call.

It has been found that the sealing surface of the duckbill valve can become contaminated with particulates from the chemistry in the test cell. The presence of contaminates can cause the valve not to seal properly. As a result, pressure in the test cell is undesirably lost.

Small reactors of this type often use stirrers within the vial in the test call to mix the reactants in the vial. Typically, the stirrers are driven by a magnetic drive that does not require any mechanical connection of the drive to the stirrer. The magnetic drives are located about the test cells. This makes a header that fits on top of the cells extremely heavy and not readily lifted off of the reactor for access to the vials.

SUMMARY OF THE INVENTION

In one aspect of the present invention, a small scale reactor generally comprises a plurality of test cells for holding vials containing reactants to be reacted. A header is disposed over open upper ends of the test cells. An injection port assembly located on the header over at least one of the test cells is configured to permit sealed access to an interior of the test cell. A seal gate located between the injection port at least one of the test cells is sealed with the test cell and the header, and slidable between an open position in which the test cell is in fluid communication with the injection port assembly and a closed position in which the injection port assembly is blocked from fluid communication with the test call.

In another aspect of the present invention, a stirrer for a small scale reactor generally comprises a body sized and shaped for being received in a vial containing reactants to stir the reactants. A magnet is removably connected to the body to permit replacement of the magnet.

In still another aspect of the present invention, a small scale reactor generally comprises a test cell sized and shaped for receiving a vial containing reactants. A stirrer is sized and shaped to be received in a vial placed in the test cell. A driven magnet operatively connected to the stirrer is capable of causing the stirrer to rotate with respect to the test cell within the vial. A driving magnet located laterally of the driven magnet and outside of the test cell is mounted for rotation relative to the test cell thereby to induce rotation of the driven magnet in the test cell and rotation of the stirrer. A drive transmits rotational force to the driving magnet from a location located to the side of the driving magnet.

Corresponding reference numbers indicate corresponding parts throughout the views of the drawings.

DETAILED DESCRIPTION

Referring now to the drawings and in particular toFIGS.1and2, a small scale chemical reactor capable of carrying out multiple chemical reactions at the same time is generally indicated at10. The reactor includes a gas distribution portion12constructed for selectively delivering and withdrawing gas from the test cells (described below) in operation. The reaction portion14include the test cells and components described more fully hereinafter. Sensors in the reactor portion14are capable of measuring temperature in the reactor portion. A pneumatic actuated assembly is provided to open and close injection ports (described hereinafter). An integrated pneumatic lift is operable to disengage a reactor top (header) from a reactor body. Coolant cells16in the reactor portion14can be used to withdrawn heat from the test cells as required. Heaters are also provided to supply energy for reaction, as needed. Electrical conduits18bring in power and control used in the reactor10. The basic construction and operation of the reactor10will be understood by those of ordinary skill in the art.

As may be seen inFIGS.3and4, the reactor includes a plurality of test cells30including lower cylinders32having open tops. The cylinders32are supported by an upper support member34. A header36is removably secured to the supper support member34by bolts38. For each of the cylinders32, there is an injection assembly40(“injection port”) mounted on top of the header36for use in injecting a substance into a testing vial V located in the cylinder. The testing vials V each contain a generally U-shaped stirrer42that is rotatable about a vertical axis in the vial for mixing reactants (not shown) contained in the vial. The stirrers42can be rotated in the vials V to mix the contents of the vials to facilitate chemical reaction. Rotation is driven using a contactless, mid-head magnetic drive system, described more fully below.

Each injection port40is constructed to receive a cannula C (e.g., a needle) through the injection port into fluid communication with the vial V while maintaining a gas-tight seal of the test cell30.FIG.6below illustrates a fragment of the cannula C received through the injection port40. The injection port comprises a base43having an opening through the base, and a cap44that is connected to the base. The cap44also has an opening. A fitting46is received in an enlarged upper portion of the opening in the base43and projects through the cap44. The fitting46has a funnel shaped open top for guiding the leading end of the cannula C into the test cell30(and more particularly into the vial V held in the test cell). A port seal48located under the fitting46is shaped to receive and sealingly engage with the fitting. The fitting46has three spaced apart sealing lips50(broadly, “seals”) that engage and seal with the cannula C when the cannula is inserted through the injection port40into a passage52leading to the vial V. The port seal48is configured to close fluid access of the passage52when the cannula C is removed. More specifically, each of the lips50is constructed to close the passage52and hold against significant internal pressures from the test cell30. In one embodiment, the lips50comprise needle seals which are capable of sealing around the cannula C when it is inserted through the port seal48. The port seal is capable of holding internal pressures of up to and including about 1,500 psi (e.g., able to withstand without leakage or failure pressures of at least about 250 psi, 500 psi, 750 psi, 1,000 psi, 1,250 psi). In contrast, the prior art duckbill seals are believed to have been capable of withstanding no more than about 200 psi. The passage52extends through the injection port and through a seal gate54(light gray) located on the bottom of the injection port. The seal gate54is engaged with the injection port base43by a top seal56which maintains a fluid-tight seal (e.g., a gas tight seal). In this embodiment, the top seal is a top O-ring56received in an annular channel in the base43of the injection port40that extends around and is spaced radially from the passage52. The seal gate54maintains a fluid-tight seal with the top of the header36by a bottom seal58, which in this embodiment is a bottom O-ring. The bottom O-ring is received in an annular channel in the header36. The annular channel, and hence the O-ring58are radially spaced from the passage52

The seal gate54is operable to open and close the passage from the injection port40. More particularly, the seal gate54seals the passage52from the injection port40. As a result, the seal gate54shields the port seal48from the high pressure in the vial V, when closed. As shown inFIGS.7and8below, the seal gate54is movable between an open position (shown inFIGS.6and7) and a closed position (shown inFIG.8).

InFIG.8, it may be seen that the seal gate54has been slid to the left so that an opening62previously aligned with the passage52inFIGS.6and7is moved to the left. The seal gate54thus blocks the passage52opening to the injection port40(and to the exterior of the test cell). As a result, the port seal48is protected from exposure to the chemicals in the vial V except when the seal gate is opened. This helps to delay loss of sealing efficacy that can occur when the lips50of the port seal48are continuously exposed to effluent from the test cell30. The top and bottom O-rings56,58prevent gas or other material from escaping from the test cell30. Notably, the portions of the top and bottom O-rings56,58that engage and seal with the seal gate54are not exposed to gas effluent trying to escape from the test cell30. This is because the parts of the top and bottom O-rings56,58that seal with the seal gate54(and with the injection port30and header) are constantly engaged by the seal gate, injection port and header so they are not exposed to the effluent. Accordingly, the top and bottom O-rings56,58remain effective for a long period of time.

As may be seen inFIGS.7and8, the seal gate54has a pair of slots64on opposite sides of the opening62in the seal gate. Tabs66are fixed to the injection port30and received in respective ones of the slots64to limit the sliding motion of the seal gate54with respect to the injection port30and the header36. Each seal gate54extends out from the injection port30(see,FIG.5) to a location where the seal gate can be grasped for pushing or pulling the gate to slide to the desired position. It is also envisioned that the seal gates54could be connected to an automated actuator (not shown) to move the seal gates simultaneously or independently.

FIG.9shows the injection port40′ with another version of the port seal48. Corresponding parts of the injection port40′ ofFIG.9will be given the same reference numerals as for those parts inFIGS.6-8, with the addition of a trailing prime. This port seal48′ works in the same manner as the port seal48illustrated inFIGS.6-8, but does not have the three, spaced apart lips50to engage the cannula C in three separate locations. The uniquely designed port seal48′ ofFIG.9can be readily and inexpensively made which can be advantageous for long term maintenance of the small scale reactor10.

As shown inFIG.5, it is possible to remove the header and stirrer assemblies70from the remainder of the small scale reactor30, and from the vials V. InFIG.5, the header36has been detached from the support member34(FIG.3) by unscrewing the bolts38. One of the injection ports40is shown detached and exploded from the header36. Referring now also toFIG.10, the stirrer assembly70is removed from the remainder of the small scale reactor30. The stirrer assembly70includes a magnet72, mounting sleeves74, a clip76and the stirrer42. The magnet72can be removed from the clip76and replaced as needed. The mounting sleeves74each receive a tubular stem78attached to the header36for rotation about the stem. When the magnet72is acted upon by a moving external magnetic field, the magnet, mounting sleeves74, clip76and stirrer42all rotated conjointly on the stem78and with respect to the vial V so that the stirrer produces mixing in the vial. As may be seen inFIGS.11and12, the stirrer42is biased to a slightly open (or V-shaped) configuration when not attached to the clip. The stirrer42comprises a base42A and legs42B extending up from the base so that the stirrer has a generally “U” shape. The “U” shape of the stirrer42is beneficial because when installed in the vial V, the central part of the vial is left open and unobstructed for the introduction of reactants into the vial. The distal end portions of each of the legs42bincludes an outwardly projecting hook42C. The hooks are received in apertures in the clip76. The bias of the legs42B holds the hooks in openings of the clips in use.

The stirrers42can be formed in any suitable manner that facilitates mixing of the reactants received in the vial.FIGS.11and12below show two other embodiments of the stirrer, designated42′ and42″, respectively. The stirrer42′ has finger-like projections80extending inward from each leg42B′ at three positions along the height of the stirrer. Stirrer42′ has a single diagonally extending fin82extending inward from the left leg42B″ to the base42A″. It will be understood that still other variations are possible. The user will select the stirrer to be used based on the nature of the reactants to be mixed in the vial V.

Referring toFIGS.15-17below, a small reactor110of a second embodiment constructed according to the principles of the present invention includes a frame mounting a number of test cell cylinders132on a mounting plate133that is supported by brackets135at either end. Corresponding parts of the reactor110will be given the same reference numerals as those used for the reactor10of the first embodiment, plus “100”. The frame further includes an upper plate134supported above the mounting plate133, and a header136mounted on the top of the upper plate. The header mounts136a plurality of injection assemblies140(“injection ports”) having substantially the same structure and function as the injection ports40shown inFIGS.1-8and described above. The mounting plate133further attaches a primary mover in the form of an electric motor (and gear reduction box)186at one end of the mounting plate.

The electric motor186is part of a mid-head magnetically coupled stirrer system. The output shaft of the electric motor186mounts a gear188that is engaged with a reduction gear190mounted on the mounting plate133. The reduction gear190meshes with a first test cylinder gear192mounted on a first exterior magnet bushing194that extends around an upper portion of the first test cylinder132. The first exterior magnet bushing194is mounted on the mounting plate133by a bearing196received in an opening in the mounting plate. The first exterior magnet bushing194mounts a driver magnet198for conjoint rotation with the first exterior magnet bushing. The first test cylinder gear192is meshed with a second test cylinder gear200mounted on a second exterior magnet bushing202to impart rotational movement to the second exterior magnet bushing. The second test cylinder gear200is meshed with a third exterior magnet bushing204and so on so that exterior magnet bushings around all six test cylinders132are interconnected for rotation of stirrers142within the test cells230. The construction and operation of each exterior magnet bushing is the same in the illustrated embodiment.

Referring again back to the first test cylinder132, it may be seen in the section views ofFIGS.16and17that the first test cylinder is mounted on the underside of the upper plate134. Inside the first test cylinder132, a vial V contains a stirrer142. More particularly, the stirrer142is attached within the vial V by a collar208that is received in an upper end of the vial. The stirrer142includes C-shaped segment on each leg142B that receive a portion of the collar208. The collar thus prevents withdrawal of the stirrer142from the vial V while permitting the stirrer to rotate relative to the vial and collar208. Enlarged ears or paddles142D of the stirrer142project above the vial V and outward from the first test cylinder132and a first interior magnet bushing210. The first interior magnet bushing is mounted by an upper bearing212to an opening in the upper plate134. The first interior magnet bushing210is also mounted on the interior of the first test cylinder132of the first test cell130by a lower bearing214. This permits the first interior magnet bushing210to rotate with respect to the upper plate134, the first cylinder132and vial V. The stirrer142is connected to the first interior magnet bushing210so that the two rotate conjointly.

The first interior magnet bushing210mounts an annular driven magnet216for conjoint rotation with the first interior magnet bushing. Rotation of the first exterior magnet bushing196and drive magnet198induces rotation of the driven magnet216and thereby rotation of the first interior magnet bushing210and stirrer142in the vial V. The other five test cell cylinders132include interior magnet bushings210, drive magnets198, stirrers142and vials V as described for the first test cylinder.

The header136is attached to the upper plate134by pairs of bolts (not shown).FIG.18below shows the header136detached and exploded from the remainder of the small scale reactor110. One advantage of the mid-head magnetically coupled stirrer system is that nothing used to drive rotation of the stirrer is mounted on the header136. Accordingly, the header can be extremely light weight (e.g., on the order of 5 lbs, on the order of 4.5 lbs or less). Therefore, it is easy for an operator to detach and lift off the header136from the upper plate134, which can be particularly important if the reactor is housed in an ergonomically constrained environment (e.g., a fume hood or drybox). The removal of the header136exposes the interiors of the test cells130. The vials V (and stirrers142) can be removed from the test cylinders132through the openings in the upper plate134shown inFIG.18. The mid-head stirrer system is completely undisturbed by removal of the vials V and stirrers42.

Referring toFIG.19above, the vial/stirrer assembly is particularly constructed to facilitate removal of the vial/stirrer assembly. As noted previously, the stirrer142has paddles142D that present relatively large, flat surfaces projecting up from the top of the vial V. When the header136is removed these paddles142D are close to the opening the upper plate134where they can be grasped to remove the vial/stirrer assembly from the test cell130. In particular, the paddles142D are designed to facilitate grasping and removing by automation, such as by a robot (not shown).

As shown inFIGS.20-23, a third embodiment of the small scale reactor310has substantially the same construction as the small scale reactor110of the second embodiment. Parts of the reactor310corresponding to parts of the reactor110will be given the same reference numerals, plus “200”. The difference in the third embodiment is the header336. The third embodiment comprises a header336which permits movement between an open position (shown inFIG.20), and a closed position (shown inFIG.21) that does not require the header to be detached from the upper plate334.

In the third embodiment, the header336includes a base plate336A and T-shaped guides336B mounted on the upper plate334. Each adjacent pair of guides336B receives a slider336C on which an injection port340is mounted. The injection ports340may have the same construction and operation as previously described. The sliders336C are each capable of independent movement relative to the guides336B and base plate336A. More specifically, the sliders336C are each attached to a corresponding pneumatic cylinder420. The pneumatic cylinders are selectively and independently operable to actuate the slide plates336C to slide between open and closed positions. In that regard, in some embodiments the slider is made of a metal that is infusion coated with polytetrafluoroethylene. In another embodiment, a portion of the slide that contacts the O-rings is cut away and replaced with a block of polytetrafluoroethylene. In the open position, the injection port340is moved entirely out of the way, permitting unobstructed access to the test cylinder332for reaching the vial V. Thus, it is not necessary to remove the header336to access the interior of the cylinders332. In the top plan view ofFIG.22below, the336B is in a position which closes the openings in the upper plate334and places the injection ports340in alignment with the openings in the upper plate. However, in another position, shown inFIG.23below, the slider336B moves down (as oriented inFIGS.22and23) to a position in which the openings in the upper plate334are exposed. The stirrers142may be seen, edge on, inFIG.23. In particular, the paddles142D of the stirrers142are exposed for grasping to remove the vial/stirrer assembly from the test cell130.

Referring now toFIGS.24-27below, a fourth embodiment of the small scale reactor510is a larger unit including 96 test cells that can receive 96 vials for conducting reactions. Parts of the reactor510corresponding to those parts of the reactor10of the first embodiment will be given the same reference numerals, plus500. The small scale reactor510of the fourth embodiment includes an upper portion510A and a lower portion510B, which is best illustrated inFIG.25below. A seal (not shown) is present between the upper and lower portions510A,510B to seal the upper and lower portions around each test cell530. A pair of clamping jaws626are provided to ensure that the upper and lower portions510A,510B are pushed firmly against each other and the intervening seal. Each of the upper and lower portions510A,510B includes angled cuts510C,510D on opposite sides that receive angled surfaces626A of the corresponding clamping jaw626to wedge the upper and lower portions510A,510B toward each other. In the illustrated embodiment, the clamping jaws626are connected to each other by threaded rods628, but other ways of securing the upper and lower portions510A,510B together may be used within the scope of the present invention. The threaded rods628can be used to draw the clamping jaws626toward each other so that the angled surfaces626A of the jaws engages the angled cuts510C,510D of the upper and lower portions510A,510B to drive the upper and lower portions together.

As may be seen inFIGS.26and27, injection ports540are disposed in a two-piece top part630mounted on the upper portion510A. The injection ports540can have the same construction as the injection ports40described previously herein. Twelve seal gates554are disposed between the two-piece top part630and an upper surface of the upper portion510A. Each seal gate554services eight injection ports540. It will be understood that in the position shown inFIGS.26and27, the seal gate554blocks communication between the injection ports540and the test cells530. Each seal gate554can be slid to another position in which the path through the injection ports540to the test cells530is open. In that position, all eight test cells530can be serviced at the same time. This could be done by a robot or manually.

As best seen inFIG.27, each row of eight test cells530communicates with a common manifold632. The manifold can communicate with an environment outside of the reactor. This could be used, for example, to control pressure in the eight test cells530.

OTHER STATEMENTS OF THE INVENTION

A. A stirrer for a small scale reactor comprising a U-shaped body including opposing legs with free upper ends, the free upper ends of the opposing legs being formed for connection to a mount for mounting the stirrer in a small scale reactor whereby a central portion between the legs is open to permit access into a space of the stirrer.

B. A small scale reactor comprising:a test cell having an open top sized large enough to receive a vial through the opening into and out of the test cell, the test cell being size and shaped for receiving the vial containing reactants;a slider located at the open top and movable relative to the open top for blocking and opening the open top.

B1. A small scale reactor as set forth in claim B further comprising an injection port assembly mounted on the slider.

C. A test vial assembly for use in a small scale reactor, the test vial assembly comprising:a test vial having an open top;a stirrer in the test vial rotatable relative to the test vial for stirring reactants in the vial;a retainer for holding the stirrer in the vial whereby the vial can be moved by griping the stirrer.

D. A small scale reactor comprising:a plurality of test cells having open tops, each sized large enough to receive a vial through the opening into and out of the test cell;a header received over the open tops of the test cells for use in closing the open tops of the test cells, the header weighing less than or equal to about 4.5 lbs.

When introducing elements of the ring binder mechanisms herein, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” and variations thereof are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, the use of “forward” and “rearward” and variations of these terms, or the use of other directional and orientation terms, is made for convenience, but does not require any particular orientation of the components.