January 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
(91) Keier, N. P.,and Roginskil, S. Z., Acta Physicochim. U.R.S.S., 22, 61-80 (1947). (92) Keier, N. P.,and Roginskir, 6. Z., Bull. acad. sci. U.R.S.S., Classe sci. chim., 1947,571-831 (93) Keier, N. P., and Roginslir, S. Z., Compt. rend. acad. sci., 52, 781-3 (1946). (94) Kemball, C . , and Rideal, E. K., Proc. Roy. SOC.,A187, 53-75, 73-87 (1946). (95) Kirillov, I.P., and Rakhlin, E. S.,J . Applied Chem. (U.S.S.R.), 19,511-16 (1946). (96) Kiselev, A. V., Mikos, N. N., Romanchuk, M. A,, and Shcherbakova, K. D., J . Phys. C h m . (U.S.S.R.), 21, 1223-36 (1947). (97) Kiselev, A. V., and Shcherbakova, K. D., Acta Physicochim. U.R.S.S., 21, 539-54 (1946). (98) Kistemaker, J., Physicu, 13,81-7(1947). (99) Kohata, K., Bull. Inst. Phys. Chem. Research, Chem. Ed., 23, 274-80 (1944). (100) Kriahnapps, T., Rao, K. S., and Reo, B. S., Proc. Indian Acad. Sci., 25A, 162-73 (1947). (101) Ledoux, E.,Chem. Eng., 55,No. 7,102-4 (1948) (102) Ibid., 55,NO.3, 118-19 (1948). (103) Lemieux, R. U.,and Morrison, J. L., Can. J . Research, 25B, 440-8 (1947). (104) Levin, V. I., Uspekhi Khim., 17,174-203(1948). (105) Lindeboom, J., Rec. tram. chim., 65,877-90(1946). (106) Livingston, H.K.,J. Chem. Phys., 15,617-24(1947). (107) Ljunggren, G., Finska Kemistsamfundets Medd., 54, No. 112, 12-26 (1945). (108) Loebenstein, W. V., and Deita, V. R., J . Chem. Phys., 15,687-8 (1947). (109) Luaces, E.L., U. 8.Patent 2,413,771(Jan. 7,1947). (110) McIntosh, R., Haines, R. S., and Benson, G. C., J . Chem. Phys., 15, 17-27 (1947). (111) MoMillan, W.G., Ibid., 15,390-7(1947). (112) Menneasier, A.,and Boucher, R., Compt. r e d . , 226, 914-16 (1948). (113) Muto, Y., J . Phys. Math. SOC.Japan, 16,104-7(1942). (114) Nederbragt, G. W., and de Jong,J. J., Rec. trag. chim., 65,8314 (1946). (115) Nusselt, W., Ver. deut. Ing., 71,85 (1927). (116) Othmer, D. F., and Josefowitz, S., IND.ENQ.CHEM.,40,723-5 (1948). (117) Perreu, J., C m p t . rend., 226, 492-3 (1948). (118) Peters, K., Reichsamt Wirtschaftsausbau, Pruf-Nr. 43, 113-20 (1940),(PB2003). (119) Placak, 0.R.,and Ruchhoft, C. C., U.S. Pub. Health Repts., 62, 697-716 (1947). (120) Pratt, T. W.,Proc. Am. Petroleum Inst., 27, 111,3847(1947). (121) Prettre, M., and Goepfert, O., Compt. rend., 225,681-2 (1947). (122) Puri, A. N., Rai, B., and Rahman, M. A., J.Indian Chm. sac,, 23,85-98 (1946)., (123) Quartaroli, A., Ann. chim. applicata, 36,260,266 (1946). (124) Quinza, 8.G.,&&fad, 21,289-301 (1944). (125) Rideal, E.K.,Nature, 161,461-2 (1948). (126) Ries, H.E.,Jr., Johnson, M. F. L., and Mefik, J. s., J . Chem. Phys., 14,465-6 (1946). (127) RoginskiI, 8. Z., Compt. rend. acad. sci. U.R.S.S., 45, 194-6 (1944). (128) Roginskil, S. Z., and Todes, O., Acta Physicochim. u.R.s.s.,20, 695-712 (1945). (129) Russell, A. S.,and Stokes, J. J., J. Am. Chem. SOC.,69,1316-19 (1947).
m!!
19
(130) Rykhilikov, G.P.,and Gapon, E. N., J.Phys.Chem.(U.5.5.B.), 20, 102941 (1946). (131) Schilling, K.,Monatsh., 77,132-7 (1947). (132) Schutz, P, W., Trans. Faraday SOC.,42,437-44(1946). (133) Sheppard, 8. E.,O'Brien, A. S., and Beyer, G. L., J. Colloid S C ~ 1, . , 213-20 (1946). (134) Sillen, L. G., Arkiv. K m i , Mineral. Geol., A22, No. 15, 22 (1946). (135) Smirnov, V. A,, and Goncharenko, S. E., J . Applied Chem. (U.S.S.R.),20,449-53 (1947). (136) Taohiki, K.,J . Chem. SOC.Japan, 65,50-2 (1944). (137) Tamamushi, B.,Sei. Papers Inst. Phys. Chem. Research, 38, 446-54 (1941). (138) Tanids, S.,Bull. Chem. SOC.Japan, 19,8-17(1944). (139) Taylor, H.N.,and Bonilla, C. F., IND.ENQ.CHEM.,39,871-6 (1947). (140) Taylor, H.S.,and Liang, S.C., J. Am. C h m . SOC.,69, 1306-11 (1947). (141) Temkin, M. J., J.Phys. Chem., 21,617-19 (1947). (142) Temkin, M.,and Levich, V., Ibid., 20,1441-57 (1946). (143) Thiele, E.W., IND.ENQ.CHEM.,38,646-50 (1946). (144) Tikhonov, A.N.,Zhukhovitskii, A. A., and Zabezhinski?,R. L., Acta Physioochinz. U.R.S.S., 22,121-36(1947). (145) Trapeznikov, A.A,, and Lipets, M. E., J. Phys. Chem., 21,10918 (1947). (146) Tsitsishvili, G.V., and Arevadze, I. Z., J . Applied Chem., 18, 572-5 (1945). (147) Tuck, N. G.M., McIntosh, R. L., and Maass, O., Can. J . Rtsearch, 26B,20-37 (1948). (148) Velasco, J. R., and Ruiz, J. O., Anales Ps.y qugm., 43, 197-210 327-46, 735-62 (1947). (149) Venturello, G.,Atti reale accad. sci. Tm'no, Classe sci. fis. mat, nat., 79, 260-2 (1943-44). (150) Ibid., 79, 275-87 (194344). (151) Verschaffelt, J. E., Bull. classe sci., Acad. roy. Belg., 32, 221-51 (1946). (152) Voevodski'l, V. V., Acta Physicochirn. U.R.S.S., 22, 45-60 (1947). (153) Vol'kenshtein, F-9 J . Phys. Chem. (U.S.S.R.), 21, 163-78 (1947). (154) Volman, D. H., and Andrews, L. J., J . Am. Chem. Soc., 70,45762 (1948). (155)Ibid., 70,457 (1948). (156) Volman, D. H.,and Klota, I. M., J . Chem. Phys., 14, 642 (1946). (157) Vreedenberg, H.A,, and van Nouhuys, H. L., Rec. trav. chim., 65,235-45 (1946). (158) Walker, W. C.,and Zettlemoyer, A. C., J . Phgs. Colloid Chem., 52,47-58 (1948). J * them* Ph%Q** 151 3% (1947). (159) (160) White, L VJr., J. Phys. Colloid Chem., 51,644-7 (1947). (161) Wicke, E., Angew. Chem., B19, 15-21 (1947). (162) Wicke, E., Reichsamt Wirtschaftsausbau, Pruf-Nr. 43, 103-12 (1940): (PB 52,003), (163) Wicke, E.,Z . physik. Chem., 193,417-28 (1944). (164) ZettlemoYert A. c., Am. Ink Maker, 26, "0. 1, 267, 69 (1948). (165) ZettlemoYer, A. e., and Walker, W. C., J . Am. Chem. Soe., 69, 1312-15 (1947). (166) ZettlemoYer~A. c.9 and Walker, w. c.,J . P h w . Colloid Chem., 51, 763-7 (1947). 52+58-64 (1948) (167) RECEIVED Ootober 6 1948.
CENTRIFUGATION JAMES 0.MALONEY
UNIVERSITY OF KANSAS, LAWRENCE, KANS.
T
HE development of the fundamental theory of centrifugation continues at a very slow pace. Information has been obtained from the studies made of German industry by American and British investigators after the war. The majority of the literature continues, however, to be of a review nature. The most extensive bibliography of centrifugation known to the writer prepared by Wilcox comprises 170 literature
(e),
references and 540 patents and covers the period from 1909 to 1946. Wiloox has classified the patents in a number of categories, making it easy t o locate the application of centrifugal equipment to various industries. Ambler (9) has written a review article giving P definition of centrifuging, the types of equipment, construction details, and a number of applications, The principal contribution of this article is in presenting some
INDUSTRIAL AND ENGINEERING CHEMISTRY
20
performance data on the crystal dewatering of ammonium sulfate, sodium chloride, and p-dichlorobenzene. Ambler rccommends a formula for calculating the residual moisture content as a function of the drying time and shows its application to sodium bicarbonate centrifuging. Froding (26) has described the development of the centrifugal clarifier from the time when i t was used as a milk separator. He presents qualitatively the variables affecting capacity, efficiency, and yield. Utilization of these units in the purification of fruit juices and extracts and the production of starch and farina are listed as typical examples of applications. Corrigan (23) again discusses the application of centrifugals to oil purification. Several attempts have been made during the past year to develop the theory of crystal drying. Ambler ( 3 )has recommended one relationship as stated above. As would be expected, the sugar industry is probably more interested in crystal drying than any other group. Behne ( 1 7 ) has given a general treatment of the problem of separating sugar from molassey. He employed the nomograph developed by Clayton (21) in handling this problem. Clayton attempted to develop a rational method for estimating the equipmcmt required to handle low gradc massecuite. He conducted experiments on three centrifuges using a Queensland sugar. The final equation he developed was: V =
kn2R3dm2v tf
where
V
volume of molasses per unit time, gallons per day aconstant speed of revolution, revolutions per minute radius of basket, inches depth of the basket, inches m = average crystal length, mm. v = residual molasses, yo crystal t) = viscosity, poises =
IC
= n = R = d =
Clayton reports that k was 2.4 X 10-7. He then developed a nomograph relating these variables. Unfortunately, the writer was unable to obtain the same results from the nornographs as from the equation. Andersson (4), who also made a study of massecuites, employed a basket having a diameter of 1200 mm. and operating between 700 and 1400 revolutions per minute. He found that the wringing time required depended upon the viscosity of the mother liquor and that the temperature of the wash water had little effect on the centrifuging operation. U'ilcox (49) in a preliminary study on a 12-inch centrifuge, employing a slurry of water and Hy-flow Super-cel, investigated the effect of revolutions per minute and cake thickness on the draining rate. The rcvolutions per minute were varied from 100 to 1800 and the cake thickness from 0.125 to 1.5 inches. Moisture determinations were made of the cake, and the amount of filtrate which could be wrung from the cake a t different revolutions per minute was determined. The draining rate varied from 0.32 to 1.8 gallons per minute. Preliminary studies were made of the filtration rate of this slurry with a test-leaf filter to determine if the filtration equations might be applied to centrifugal filters. It was not possible with the data obtained to establish any clearcut relationship between the performance of the centrifuge and a test-leaf filter, nor to develop any scale-up proposal, and he proposes that the study be continued. Schmid (&) gives methods for testing and calculating centrifugal equipment. The description of centrifugal apparatus employed in Germany can be found in a number of the reports issued by the Office of Technical Services, U. S. Department of Commerce. The reviewer has not been able to isolate all the descriptions of this equipment nor its application from the large number of reports that have been issued. It is believed that centrifugal manufacturers could well consult the reports on phases of the German chemical industry which might have employed centrifugal equip-
Vol. 41, No. 1
ment. Details, photographs, and a description of the Rekord continuous centrifuges have been obtained (14). The production of centrifugals by the Westfalia Separator Company, the Mielewerice A.G., and the Fr. Iirupp A.G. has been reviewed (6). The production of the H. Icrantz Machinenfabrik; the I. G. Farbenindustrie, Dormagen, and Elberfeld; the RIatthes and \Yeher, Duisburg; and the Westfalia Separator Company have been reported by Broadbent (18, 19). The application of the Escher-Wyss centrifuge to crude sodium bicarbonate is described. Details include basket size, speed, and output. Bn Escher-Wyss machine was also used at I. G. Farbenindustrie, Elberfeld, on hexamethylenetetramine. Details of centrifugcs manufactured by Lokomotivfabrik Krauss and Company (15) have been reported. Study of these reports will reveal that many of them are repetitive, but individuals interested in all the details of the equipment may find it desirable to read each of them, inasmuch as different groups made these surveys. Photographs and drawings of Westfalia equipment are also to be found in the Publication Board reports (7-13). The application of centrifuges to pharmaceutical and dye manufacturers has been described (30). Sutcliffe (44) has reviewed the design, construction, and production of high-speed centrifuges. Cobbing (22), in describing German chemical equipment, treats centrifuges. hierco centrifugals have been used to replace table for the separation of starch and gluten. Taylor (46) gives a detailed description of these two units. His performance figures include space, separating efficiency, capital investment, labor, and power. Pederseen (36)describes the application of a Bird centrifuge to the separation of lime sludge in the Marshalltown, Iowa, water works. Rejtharek (37) describes factory trials of a Weston centrifuge on sugar liquors. The use of a high-speed centrifuge for the clarification of beer worts and for separating yeast has been described by Loncin (34). The application of filters and centrifuges for the separation of iron-free alum is reported ( 2 7 ) . Urie (488) has described a process for the separation of mixed rare earth oxides, in which the centrifuge employed had a filter bed of sawdust 2 inches thick, replaced after each filtration. Before using this technique, sand, kieselguhr, and other filter aids had been tried. The use of the tor Meer batch-type centrifuge in the filtration of soda ash has been described (6). Steel rubbercovered baskets were employed and the filter medium was wool flannel held in place by a stainless steel screen bolted to the basket. The centrifugal filtration in Germany of sodium chloride, sodium bicarbonate, ammonium carbonate, sodium perborate, and sodium percarbonate has been described (6, 33). .4 method has been suggested by Hancock and Brown (28) for evaluating the settling properties of pigments in paints using a centrifugal. A centrifuge for separating cheese from whey has been credited to Streaynski (43). The principal feature of this unit is that it permits continuous separation of a liquid from a solid in a solid bowl machine in which the solids have a lower specific gravity than the liquid. Eckers (25) has obtained a patent on a centrifuge for separating starch and fruit juices. Roberts and Stevens (38) have developed a control mechanism for carrying out mashing operations in a perforate bowl centrifugal. Other design patents have appeared during the year (1,2,20,%9,85,39,4?). The principal activity on ultracentrifugal work seems still t o be concentrated in the laboratories at Uppsala, Sweden. Svedberg (45) has surveyed the ultracentrifugal sedimentation technique for the determination of molecular weight. A review of the application of the ultracentrifuge in the study of the physicochemical aspects of cellulose has been made ( 3 2 ) . The application of the ultracentrifuge to the study of cellulose glycolic acids and Hevea latex is reported (16, 31 ). A ball-bearing drive for the ultracentrifuge is described by Ecker and Blum (ad). A nomograph for particle-size determinations using the Sharples centrifuge has been presented b y Saunders (41). Sanigar and
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 1949
Hambelton (40) report on the explosion of the rotor of an airdriven centrifuge. LITERATURE CITED
(1) Aktieb, Brit. Patent 584,538(Nov. 1, 1944). (2) Ibid., 584,714 (Jan. 12, 1945). (3) Ambler, C. M.,Chem. Eng. Progress, 44,No.5, Trans. Am. Inst. Chem. Engrs., 405-10 (1948). (4) Andersson, G.,Sooker Handl., 2, 379-406 (1946). (5) Anon., U. S. Dept. Commerce, Office of Technical Services, P B 58,260. (6) Ibid., P B 81,287 (April 1947). (7) Ibid., PB 86,399. (8) Ibid., P B 86,400. (9) Ibid., P B 86,401. (10) Ibid., P B 86,402. (11) Ibid., P B 86,403. (12) Ibid., P B 86,404. (13) Ibid., P B 86,405. (14) Ibid., PB 88,153. (15) Ibid., P B 88,154. (16) Banderet, M., J.chim. phys., 44,52 (1947). (17) Behne, E.R., Intern. Sugar J.,49,261-3,295-7 (1947). (18) Broadbent, F., U. 9. Dept. Commerce, Office of Technical Services, P B 12,669 (October 1945). (19) Ibid., P B 22,184(February 1946). (20) Bromley, A., Brit. Patent 586,077 (Oct. 30, 1944). (21) Clayton, J. L., Intern. Sugar J.. 49,236-9 (1947). (22) Cobbing, J. H.W., U. 8. Dept. Commerce, Office of Technical Services, PB 25,647. (23) Corrigan, B., Am. Citg, 42, 98 (1947). (24) Ecker, P. G.,and Blum, J., Rev. Sci. Instruments, 19, 399-400 (1948). (25) Eckers, C . G., U. S. Patent 2,443,310(June 15, 1948).
21
(26) Froding, E., Tekn. Tidskr., 78,85-91 (1948). (27) Gee, E. A., and Cunningham, W. H., U. S. Bur. Mines, Rept. Inneat. 4191 (1948). (28) Hancock, A.,and Brown, T. F., J . Oil Colour Chem. Assoc., 30, 317-37 (1947). (29) Hartley, A. J., Brit. Patent 588,589 (March 1, 1945). (30) Hopworth, H.,et al., U. S. Dept. Commerce, Offioe of Technical Services, P B 28,951(December 1945.) (31) Huret, M.,Rev. cen. caoutchouc., 25,124-9 (1948) (32) Jullander, I., J. Polymer Sci., 2, 32945 (1947). (33) Lawrence, J., et al., U. S. Dept. Commerce, Office of Technical Services, PB 7944. (34) Loncin, Marcel, Rev. fermentations et inds. aliment., 2, 61-70 (1947). (35) Loumiet, J. P., Brit. Patent 592,154(May 23, 1944). (36) Pedersen, H.V.,Am. Citg, 43,86-7 (1948). (37) Rejtharek, A., Listy Cukrovar, 63,201-5 (1947). (38) Roberts, E., andstevens, G. E., U. S. Patent 2,347,157(April 18, 1944). (39) Rousselet, J. A. N., French Patent 860,206(Jan. 9, 1941). (40) Sanigar, E. B., and Hambelton, J. H., J . Franklin Inst., 244,23440 (1947) (41) Saunders, E., Ana?. Chem., 20,379-81 (1948). (42) Schmid, U.S.Dept. Commerce, Office of Technical Services. P B 6239. (43) Strezynski, G.T.,U. S. Patent 2,436,498(Feb. 24, 1948). (44) Sutcliffe, A. R.,U. S. Dept. Commerce, Office of Technical Services, P B 56,260. (45) Svedberg, T., Enhavour, 6, 89-95 (1947). (46) Taylor, R. L., Chom. Inds., 62,54-7 (1948). (47) Tecelemit, Ltd., Brit. Patent 584,292(Dec. 22, 1944). (48) Urie, R. W.,J. SOC.Chem. Ind., 66, 437-9 (1947). (49) Wilcox, A. C., University of Kansas, thesis,. 1947. RECEIVED October 20, 1948.
CRUSHING AND GRINDING mg
A
LINCOLN T. WORK,
METAL a THERMIT C O R P O R A T I O N , R A H W A Y , N. J.
NOTHER year since the last report (19)brings the steady encroachment of science and sound engineering into the complex art of crushing and grinding. To make it a science, the measurement of particle size must also progress-with regard t o both improvement in methods and more extended use of present methods. The year brought a revised and enlarged edition of Dallavalle’s “Micromeritid’ (6). The revision is extensive. Five new chapters have been added, and all of them bear either direct scientific information or some practical views on the subject of this review. The behavior of particles under pressure has applications, in addition to powder metallurgy, in crushing and grinding. Some of the problems of storage and handling and the very action of many types of mills need an understanding of this. Diffusion of particles and dust clouds bears on particle size analysis and on classification equipment. Surface properties are important in measurement and in the final product of mill operations. The theory of sampling should contribute t o an everpresent problem in this unit operation. In addition, the treatment of the theory of fine grinding gives an orderly analysis of friability, grindability, ball mill grinding, theory of crushing, particle size distribution of ground material, surface area and energy, and explosive shattering. Although some of these subjects are not yet practically applicable t o crushing and grinding, all will give food for thought in tomorrow’s developments. Sieve measurement as a control in powder metallurgy is under study at the National Bureau of Standards ( 3 ) . I t has been noted that surrounding conditions such as humidity may have a significant bearing on the weights of retained solids. This adds
to the general knowledge of the subject and may lead t o modification of test or a specification of acceptable conditions. Matheson (8) shows some modification in the Roller method of analysis for subsieve separations. Electron microscopy is further advanced in two papers. Watson (18)shows a number of errors that may creep into the use of this tool, and shows how simple precautions make it possible t o obtain reproducibility within about 5%. Hanson and Daniel (6) reduce measurement and representation t o a mechanical function, having a scanning device for electron micrographs and a mechanical histogram computer. Walton (17) differs from Heywood and contends that there is significance in the statistical diameter of Feret. Jacobsen and Sullivan (7) show that sedimentation procedures are based on sound principles. Whether it be by sedimentation pan, cup, or specific gravity cylinder, results should be significant down t o about 1 micron. They show a modified balance for such testing. A buoyancy factor is introduced t o speed up testing, as it avoids the necessity for complete sedimentation. They advocate the use of the sedimentation centrifuge for fine sizes up t o 1 or 2 microns and show ways to correlate data between the two methods. Their contributions t o date are a substantial addition t o sedimentation literature. Rossi (14), apparently beginning a series of papers, gives a calculation of the sedimentation curve, while Saunders (15) offers a nomograph for particle size measurement with the Sharples supercentrifuge. Schachman (16)presents a simple approximation t o express the sedimentation constants in the Sharples supercentrifuge, derived from experiments on closely fractionated bentonite. Bardwell and Siverts (1)have made a critical study of the size
