Abstract:
A combination reflux/distillation apparatus is provided having interchangeable reflux and distillation columns, a segmented collection trough and an integrated indirect heating provision. The apparatus is uniquely adapted for refluxing and distilling small quantities of materials without the losses attendant to larger apparatus.

Description:
FIELD OF THE INVENTION 
     The present invention is a combination distillation/reflux apparatus that is portable, inexpensive and uniquely adapted for use with relatively small samples in the order of less than 5 ml. 
     BACKGROUND OF THE INVENTION 
     Many laboratory experiments require distillation and reflux processes. The conventional equipment for performing such processes includes Bunsen burners, retorts, reflux columns, receptacles, and support stands. The standard size of such equipment is appropriate to processing a quantity of liquid a quarter (¼) liter or more. Smaller quantities cannot be effectively distilled or refluxed in standard equipment. The liquid is boiled away and lost in the large container before it can effectively distill or reflux. 
     The time required to distill or reflux liquid diminishes with the quantity. So the time required to process a quarter liter, is proportionally greater than when the quantity is 2.0 ml. to 3.5 ml. 
     Standard distillation and reflux equipment is expensive and requires a stable laboratory installation. Because it is fragile and cumbersome, it is not easily portable. 
     Accordingly, there is a need for laboratory equipment which can process relatively small quantities of liquid (e.g. 2.0 ml. to 3.5 ml); and which is light weight, inexpensive, non-fragile, and easily portable. With such equipment, effective laboratory experiments can be carried out in circumstances that do not accommodate the installation of standard laboratory equipment such as classrooms or makeshift laboratories in remote places. 
     DESCRIPTION OF THE PRIOR ART 
     The prior art considered relevant to the present invention is the conventional laboratory equipment, such as Bunsen burners, retorts, reflux columns, receptacles and support stand presently used to perform experiments involving reflux and distillation. Applicant is not presently aware of any prior art that teaches the specific adaptation of equipment to process small quantities of liquid and provide the other advantages that the present invention offers. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a combination reflux and distillation column that includes a first vessel for holding a volatilizable liquid and a second larger vessel containing a heating medium. The first vessel is at least partially immersed in the heating medium, and both vessels have upper openings that engage with a cap that completes closure of the second vessel and provides a connecting passage between and an upward projecting tubular column. A support arm extends from the cap to maintain the column and both vessels in upright alignment. The upward projecting column can be interchangeable reflux and distillation columns. 
     In one embodiment, the cap is provided with a transverse orifice to accommodate a temperature sensing device. 
     In another embodiment, a segmented collection trough is provided at the open unconnected end of the distillation column to receive distillate fractions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the apparatus of the invention as used in conducting reflux procedures. 
     FIG. 2 is a sectioned front elevation of the distillation and refluxing arm of the apparatus of the invention. 
     FIG. 3 is a perspective view of the apparatus for conducting distillation procedures; and 
     FIG. 4 is a perspective view of a distillation fraction collector of the apparatus of the invention shown mounted on a retort stand. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is directed to laboratory distillation and refluxing apparatus that is light weight, inexpensive, non-fragile, easily portable, and capable of refluxing and distilling relatively small quantities (2.0 ml. to 3.5 ml.) of liquid. 
     The amount of heat necessary for any experiment may be generated by a small microburner. 
     The time required to reflux or distill is proportionately less than with conventional equipment, because small quantities of liquid can be processed. 
     The purity of the resulting products is high when compared to standard procedures with conventional equipment. 
     The invention will be more fully appreciated by having specific reference to the drawings which illustrate a preferred embodiment thereof. 
     Directing attention to the drawings, the laboratory reflux and distillation apparatus is shown consisting of a distillation and refluxing arm  10 , a small capacity (1 dram) reaction vial  12 , a larger capacity (8 dram) heating vessel  14 , a refluxing column (as shown in FIG.  1 ), a distillation column  18  (as shown FIG.  3 ), a thermometer  20  and a distillation fraction collector  22  (as shown in FIG.  4 ). 
     The distillation and refluxing arm  10  is molded from a suitably resilient plastic material and includes at one end a split sleeve  24  and at its other end a body  26  in which the vials  12  and  14 , the refluxing column  16 , and the distillation column and the thermometer  20  are releasibly engageable in use. 
     The body portion  26  of the arm  10  of the apparatus is shown in FIG. 2 to include first and second concentrically arranged threaded caps  28  and  30 , a first passage  32  which extends between the cap  30  and an open socket  34  at the upper end of the body and a second passage  36  which intersects the passage  32  and is open to a second socket on the side of the body as shown in the drawing. The refluxing column or tube  16  and distillation column  18  respectively are glass tubes which are partially filed with 3 mm glass beads  37  which collectively provide a large area cooling surface which condensation takes place in the columns in use. The reflux column is a linear tube, having a length of between 21.5 cm and 30.0 cm which, in use, is held vertically and the distillation column  18  is a similar arrangement which has its free end including cooling beads folded downwardly, as shown in FIG. 3, for distillate discharge. The distillation retort tube has a vertical length of about 6 cm to 6.5 cm and downwardly inclined length of 12 cm. The tubes  16  and  18  are pinched to form a constriction  17 , which is small enough that the glass beads cannot pass through it. 
     The thermometer  20  is a conventional linear thermometer which ranges from 0° to 200° C. 
     In use in conducting refluxing experiments with the apparatus of the invention the apparatus is arranged as illustrated in FIG. 1 with the split sleeve  24  of the distillation and refluxing arm  10  being frictionally engaged over a retort stand  40  which carries on its lower end a rubber bung  42  which is engaged in a well of the base member  44 . The reaction vial  12  filled with reagents suitable for whatever refluxing experiment is to be carried out with the apparatus and its screw threaded mouth is screwed into the cap  30  up against a resilient seal in the body  26  of the arm  10 . The heating vessel  14  is partially filled with silicon oil, the boiling point of which is between 200° C. and 275° C., and the threaded mouth of the vessel is threadedly engaged with the cap  28  on the arm body  28  with the reagent in the vial  12  at least partially immersed in the oil in the vessel  14 , as shown in FIG.  1 . The bulb portion of the thermometer  20  is inserted into the body socket  38  and pressed through an O-ring at the mouth of the passage  36  to be situated in and across the body passage  32 . The refluxing column  16  is similarly pressed into the vertical socket  34  and the O-ring situated in it to be sealingly supported in the socket. With the apparatus now in place a methylated spirits microburner  46  is located in a well of the base  44  beneath the heating vessel  14  and its wick is lit. 
     Refluxing occurs in a very gentle manner as the heated oil in the vessel  14  evenly heats the reagent in the vial  12 . Refluxing may progress for time periods of anywhere from 5 to 30 minutes. The heat source is now removed and the system is permitted to cool at which time the refluxing column or tube  16  is removed. 
     The distillation column  18  is now attached, as shown in FIG. 3, to the upper end of the arm body  28  in the same manner used to locate the refluxing arm. 
     The fraction collector  22  consists of a trough  48  in which a strip  50  of connected micro-well (5 mm×10 mm) distillate collection vessels  52  are slidably located and which has a central downwardly dependent stud on its underside which is frictionally engageable in a bore in a retort stand arm  54 . For distillation experiments the arm  54  together with the tray  48  is engaged with a retort stand  40  and base  44 , as shown in FIG.  4 . The height of the upper level of the micro-well strip  50  is adjusted, by moving the arm upwardly or downwardly on the stand  40 , to be very slightly below the outlet lip of the distillation retort tube column and is positioned so that a selected collection vessel  52  is located beneath the lip of the distillation retort tube. 
     The microburner  46  is lit and the oil in the heating vessel  14  is heated to a temperature sufficient to initiate the distillation process. The thermometer  20  serves as an indicator for the separation of the mixture. As the temperature changes, this physical feature serves as an indicator of the vapors that are being boiled over as temperature is a significant parameter of purity. The distillate is collected in the collection vessels  52  of the fraction collector  22  in a manner convenient to the experiment. 
     Other modifications and alternatives to the herein described procedures and components will be apparent to those of ordinary skill in this art and are considered to fall within the scope of the claims defining this invention.