INDUSTRIAL AND ENGINEERING CHEMISTRY
348
Summary A new mill has been developed, by means of which inks and paints over 8. wide consistency range can he thoroughb ground without contamination. This new apparatus consists essentially of two truncated glass cones, one of which is fitted inside the other, together with a plunger feed mechanism which forces crudely mixed ink into the annular space be-
Vol. 14, No. 4
tween the conical sections, one of which is rotated with respect to theother. For example, theouter sectionof a gronndglass joint is fitted with a plunger at the small end, and ink forced by a rotating appropriately slotted stopper. The efficiency of this mill has been tested relative to that of a laboratory 4 x 8 inch three-roller mill as well as hand milling. Advantages are excellent dispersion and freedom from metallic contamination. with whites and light cola
A Dialyzing Concentrator CARL C. SMITH A N D CHARLES D. STEVENS Cardiac Laboratory, College of Medicine, University of Cincinnati, Cincinnati, Ohio
ines arramed in nardel. each 165 cm. (5.5 feet) lonp. These --. ..~ .
A simple apparatus for simultaneous dialysis and concentration has been devised. The rates of evaporation of water from 5 per cent sucrose solutions and from distilled water through Visking casings were observed under various conditions. By use of two fans and a steam unit heater to blow air past eight Visking casings, a maximum rate of evaporation of 1.5 liters of water per hour was obtained.
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led through coils in the r&ervoir t o Geep the rnaterial'cool, and thence through a rotameter (Fischer & Porter Co:, Philadelphia, Penna.) to measure Its rate of flow. From there I t runs into the dialyzing jar, overflows onto a tray, and runs into the trough of the laboratory bench. To gather the data in Table I we& p d dry-bulb thermometers were placed beside the caslngs hireetly ln front of the unit heater, and a thermometer was placed inside one
A (I,
NUMBER of methods for dialyzing have heen reported 8, 7, 8, 10, 18), and procedures have been devised
for concentration by removal of solvent through membranes (8,18, 16). Only a few techniques have been employed which permit simultaneous concentration and dialysis'and in general these have been expensive or complicated. The need for a simple procedure which would permit dialysis and concentration of 20 to 30 liters of kidney extract a day led the authors to investigate the adaptability of some methods previously reported. Simms' method (11) w&s rapid but required strong collodion bags and could be adapted only wi>b diffiogty to the authors' larger volumes of material. Wet Viskiug casings of 1.4 or 1.875 cm. or 24/Anch) diameter 6Ued with water burst when from 200 to 3M) mm. of mercury pressure were applied and so could not be substituted directly in a modified Simms' apparatus. The authors have employed a maximum pressure equal to tbat of 140 mm. of mercury in their apparatus Thalhimer's method (id), employing CON SiNp in dialysis, introduced considerable amounts of carbobydrate into the extracts, which wasundesirable. Similar methods employing ammonium sulfate or other salts were objectionable for like reasons. Ultra6ltration through membranes on Seitz flters has heen useful in industry (P), hut was not feasible in the authors' laboratory. They found that Koher's pervaporation technique (4, 6, 6 ) could be readily adapted to their laboratory equipment, and the apparatus pictured in Figures 1 and 2 has proved capable of handling materials without requiring much attention. Since few observations on rates of concentration and dialysis by any of these methods have been reported, the authors have memured rates and temperatures with their equipment under varying conditions which may afford indications of the value of this type of apparatus.
Apparatus The apparatus rnn&ts of a reservoir, Irom e bottom owlet of which the rnxtrrial IO h conrsntrntd and dialyzed Row3 by gravity through gltm and rubher t U h g inro eight Yisking cas-
FIGUBE1. APPARATUSIN OPERhTION
April 15, 1942
Starting Material
ANALYTICAL EDITION
TABLEI. DATAON DIALYSIS
Diameter of Casings
Temperature in Reservoir
Inch
OC.
'C.
'C.
'C.
24.5 24.5 27.5 29 25.5 24.5 29 32 24.5 24.5 27.5 23.5 24.5 28 23 23.5 27
18.5 17.5 28 30 19.5 20 22 26 18.5 17.5 27.5 22 17.5 28 20 18 28
29.5 29.5 64 64 29.5 29.5 29 32 30 26.5 64 37 27.5 64 29 28 64
17.8 16 28 30.6 18 18 20.6 24 17 17 28.5 20.6 16 29 19 16 28
Diatiiled H,O
18/32 18/32 18/32 18/32 18/32 18/32 18/32 18/32 6% sucrose 18/32 18/32 18/32 b%sucrose 24/32 24/32 24/32 Diatilled Hz0 24/32 24/32 24/32 Estimated figure.
349
Temperature in Casing
Temperaturein Front of Unit Heater
WetBulb Ternperature
Temperature above Jar OC.
28 28.5 35 40 29 29 29 31 28 28 32 25 25 34 28.5 27.5 34
Temperature in Jar
'C. 21 21 22 25 22 22 22.5 26 21.5 21.5 22 22 22.5 24.5 22 21 22
of the casings at the same level. Thermometers were also placed in the dialyzing jar, 30 cm. (1 foot) above it, in the reservoir, and on the wall 180 cm. (6 feet) to one side of the apparatus.
Tap Water Flow Rate
L/min. 0.99 0.99 0.99 0.57 0.54 0.54 0 0 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99 0.99
Fans
.,
2 on 2 on 2 on 2 on 3 on
..
..
..
2 on 2 on 2'on 2 on
2'on 2 on
Duration of Heater Experiment Hours Min. .. 1 20 2 50 On 1 10 On 4 .. 1 .. 1 40 .. 16 , .. 12 40 2 io .. 2 40 On 3 . .. 2 10 . 1 20 On 2 40 2 40 3 30 On 2 50
.. ..
.. . .
. ..
Final Sucrose Evapo- Concentration ration ReaerRate Casings voir L./hr. Q . / l O O ml. 0.23 0.74 .. .. 1.29 .. 1.14 . 0.57 .. .. 0.57 ., .. 0.12 .. 0.17 0.17 416s 4:a5 0.54 6.49 4.97 0.95 9.21 4.97 0.12 4.38 5.00 0.65 5.28 5.06 1.34 7.53 5.04 0.29 0.76 .. 1.47
.. . ..
.. .. ..
.. ..
.. ..
Sucrose Dialyard
Out G./hr.
.. .. .. .. .. ..
ii:5 13.5 13.3 18.9 23.3 25.9
.. ..
..
Table I shows that evaporation from the casings proceeded slowly without the use of fans. The rate of evaporation waa tripled if two fans were allowed to blow air past the casings, provided humidity and room temperature remained about the same. The use of steam in the unit heater practically doubled the rate of evaporation over that when only two fans were used, but produced increased temperature within the casings. The presence of sucrose in the casings always decreased the rate of evaporation. The rate of dialysis depended to a considerable extent on the surface of casings immersed in the dialysis jar, and could be increased by using longer casings. Among the advantages of this type of apparatus in the authors' laboratory are its low cost, its automatic operation, its high rate of concentration, the readiness with which it may be adapted to handle more or less material, the removal of dialyzable materials simultaneously with concentration, the gradual passage of nondialyzable material from the upper heated zone of concentration to the lower cooler zones of the casings (provided the nondialyzable material has a higher specific gravity than water), the continual supply of the most dilute material to the zone where the evaporation rate is highest, the ease of removing the material from the casings when operations are completed, and the small amount of equipment which needs cleaning. No trouble with foam, spray entrainment, or overheating such as may occur in vacuum distillations has been encountered with this apparatus. Disadvantages encountered may be: decreased evaporation rates when high humidity prevails, breakage of casings, collection of dust on the outside of the casings facing the fans, collection of some solids on the inside of the casings if the material is overconcentrated, and the slight heating of the material within the casings when steam is run into the unit heater.
Acknowledgment J
The authors are indebted to Fred Blanchard for technical assistance in gathering these data.
Literature Cited
FIGURE2. RESERVOIR, COOLING COILS,TUBECONNECTIONS] (WITH DETAIL),AND TUBESWITH LOWERENDS DIALYZING
(1) hitken, H. A., J . B i d . Chem., 90, 161 (1931). (2) Hanke, M. T., and Koessler, K. K., Ibid., 66, 495 (1926). (3) Hartman, F., J . A m . h l e d . Assoc., 115, 1989 (1940). (4) Kober, P. A,, J . Am. Chem. Soc., 39, 944 (1917). (5) Ibid., 40, 1226 (1918). (6) Kober, P. A, Proc. SOC.Ezptl. Biol. .Wed., 14, 87 (1917). (7) Kunitz, &and I., Simms, H. S.,J . Gen. Physiol., 11, 641 (1928). (8) Korthrop, J. H., and Kunitz, M., Ibid., 9, 351 (1926). (9) Parsons, C. H., personal communication. (10) Schmidt, A.-4., Biochem. Z.,225, 216 (1930). (11) Simms, H. S., J . Ezptl. M e d . , 51, 319 (1930). (12) Taylor, A. R., Parpart, A. K., and Ballentine, R., IND.ENO. CHEM., ANAL.ED.,11, 659 (1939). (13) Thalhimer, W., Proc. SOC.Ezpt2. Bid. Med., 37, 639 (1938). (14) Ibid.,41, 230 (1939). (15) Ibid., 41, 233 (1939).
