Liquid Separator for Use under Vacuum. Kortham Warren Corp., Stamford, Conn. STAXDARD
Stopcocks G and H are opened and L and h’closed until it is necessary to remove t,he water which has collected. The collected water may be removed without interrupting the boiling process by closing G and H , opening L , and drawing off the water through M . The vacuum may be re-established by closing L and M , opening G slowly, and allowing the water xhich has collected to flow into 0 by opening H The condensed liquids drop through the neck at E into the separation chamber, F , where the toluene and water have time to effect a fairli good separation. Better sepaation is brought about by dividing the separation chamber in two parts, F and P , than by using one longer chamber: this may be due to the fact that the liquids have to travel over the glass surface of F and a better separation is realized. The return of the toluene to the boi1i;g chamber is accomplished by connecting a return line to B. If continuous extraction is not desired, B may be connected to a receiving flask which is connected to the same vacuum line as is D.
Henry J. Wing,
method for removing water from various materials
A and reaction mixtures is to add a liquid such as toluene which is immiscible v,ith water, boil the mixture, condense the vapors, and separate the condensed liquids. In many cases (Gilman, “Organic Syntheses”, Vol. 1, p. 412, S e w York, John Wiley & Sons, 1932) the organic liquid is returned to the boiling vessel, Xvhile the water is collected or discarded. I n some cases, as in the drying of a nitrocellulose mixture, it is desirable to carry out this boiling under vacuum in order to keep the temperature as low as possible. Under these conditions, when toluene is used, the separation is frequently rather slow, because of the formation of very fine droplets of the toluene in the water. The collection of the water under vacuum offers difficulty, particularly if comparatively large amounts are to be Collected.
The dimensions shown have been found useful for toluenewater mixtures. Other liquids lighter than wate‘r may also be used. The apparatus may be used with liquid heavier than water if intermittent operation is used or if the heavy liquid is to be collected.
Glass Circulating Pump for Gases and Liquids. J. E. Sickels, Koppers Co., Inc.. Multiple Fellowship on Tar Synthetics, hIellon Institute, Pittsburgh, Pa. vAcuu&x-operatedglass pump for the circulation of gases in a
A closed system described by Kester [Kester, E. B., IXD.ENG.
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CHEhr., AKAL.ED., 4, 298 (1932)l finds a variety of laboratory applications. I n many instances, however, the intermittent flow obtained with this pump is undesirable. To overcome this disadvantage, a modified pump has been developed that gives a nearly continuous flovi and is suitable for pumping either gases or liquids. The improved design employs t x o mercury pistons instead of one and is more compact t,han the Kester device in that the pump and valves are incorporated in a single unit.
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Application of vacuum a t a causes the mercury level to fall in b, c, and d, and to rise in e and J until the level in cup g falls beloK the loFer end of the tube e. As g becomes empty, atmospheric pressure forces the mercury from e into f and air rushes in through e to fill the evacuated space, thus causing the mercury to fall in f and rise in b , c, and d until it again overflows into g. The cycle then repeats itself. On connecting h and i to the inlet and outlet of the system through which the gas or liquid is to be circulated, there is a f l o ~of the pumped medium through the system during both the rising and falling of mercury in pistons b and c. As a result, the flov is almost continuous, being interrupted only momentarily during each half-cycle.
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The illustration shows an all-glass apparatus which promotes complete separation of the water and toluene. It makes i t possible to return the toluene to the extraction vessel and to collect the water and remove it from time to time.
The construction of the pump may be altered to enable operation by compressed air, by extending d below g far enough to maintain a mercury seal between d and f,upon applying air pressure a t j. By modifying dimensions or rate of application of vacuum-or compressed air, the pump can be made to operate over a wide range of pumping rates.
The tip of the condenser from the boiling vessel or drying chamber is inserted in the top of the collecting device a t E. The vacuum connection is made at the end of the outlet tube, D. The small condenser on D is useful in effecting the final condensation of the vapors, so that the vapor loss is as small as possible. 216
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