72
INDUSTRIAL AND ENGINEERING CHEMISTRY
(52F) Kipling, J. J., and Tester, D. A., J . Chem. SOC.,1952, pp. 4123-33. (53F) Zotelkov, N. Z., J . A p p l . Chem. U.S.S.R., 24, 641-7 (1951). (54F) Kurosaki, Shigehiko, J . Chem. SOC.Japan, Pure Chem. Sect., 73, 606-10 (1952). (55F) Liang, S. Chi, J . Phys. Chem., 57,84-7 (1953). (56F) Loeser, Edward H., Harldns, Wm. D., and Twiss, Sumner B., Ibid., 57, 251-4 (1953). (57F) Maggs, F. A. P., Nature, 169, 793-4 (1952). (58F) Maggs, F. A. P., Research Correspondence, 6, 13-14s (1953). (59F) Marshall, Patricia, A., and Moore, Walter J., J . Am. Chem. SOC.,74,4779-83 (1952). (60F) Maslan, F. D., Altman, M., and Aberth, E. R;, J . Phgs. Chem., 57, 106-9 (1953). (61F) Mignolet, J. C. P., J . Sci. Instr., 30, 15-17 (1953). (62F) Milligan, W. O., and Whitehurst, Harry B., J . Phys. Chem., 56, 1073-7 (1952). (63F) Milligan, W. O., and Whitehurst, Harry B., Rev. Sci. Instr., 23, 618-20 (1952). (64F) Mooi, John, Pierce, Conway, and Smith, R. Nelson, presented a t the 27th National Colloid Symposium, Ames, Iowa, June 1953. (65F) Neimark, I. E., and Sheinfaln, R. Yu., Kolloid. Zhur., 15, 4550 (1953). (66F) Ibid., 15, 145-51 (1953). (67F) Ono, Shd, Busseiron K m k y C , No. 19, 1-8; No. 21, 46-58 (1949) ; NO.23, 10-17 (1950). (68F) Osawa, Fumio, and Sat& Hisanao, Ibid., No. 20, 94.-101 (1949). (69F) Csawa, Fumio, and Sat& Hisanao, Ibid., No. 22,1425 (1950). (70F) Papbe, Denis, Compt. rend., 234,25368 (1952). (71F) Pierce, Conway, and Smith, R. Nelson, J . Am. Chem. Soc., 75, 846-8 (1953). (72F) Polley, M. H., Schaeffer, W. D., and Smith, W. R., J . Phy8. C h m . , 57, 469-71 (1953). (73F) Puri, Balwant Rai, and Bhushan, Vidya, J . Sci. Ind. Research, 11B, 504-5 (1952). (74F) Puri, Balwant Rai, Lakhanpal, M. L., and Varma, Balvir, J. Indian Chem. Soc., 29,841-5 (1952). (75F) . , Robinson, Sam P.. U. S. Patent Application 785,180; Ofich2 Gaz., U.S. Pat. Ofice, 657,1584 (1952).
Vol. 46, No. 1
(76F) Rockwell, Paul O., and Goshorn, John C., U. S. Patent 2,612,434 (Sept. 30, 1952). (77F) Sadek, Hussein, Euclides (Madrid),12, 133-40 (1952). (78F) Sakaki, Tomohiko, J. Chem. SOC.Japan, Pure Chem. Sect. 73, 217 (1952). (79F) Ibid., pp. 218. (80F) Ibid.,pp. 680-2. (81F) Sarakhov. A. I., Dokladu Akad. Nauk S.S.S.R.. 86. 989-92 (1952). (82F) Schreiner, G. D. L., and Kemball, C., Trans. Faraday Soc., 49, 292-9 (1953). (83F) Shimokawa, Junichi, Busseiron K e n k y c , No. 58,8-16 (1953). (84F) Simha. Robert, Frisch, H. L..and Eirich. F. R., J . Phwa. Chem., 57, 584-9 (1953). (85F) Singleton, J. H., and Halsey, G. D. Jr., 123rd Meeting, AMERICAN CHEMICAL SOCIETY, Los Angeles, Calif., March 1953. (86F) Snelgrove, J. A., Greenspan, H., and McIntosh, R., Can. J . Chem., 31, 72-83 (1953). (87F) Snelgrove, J. A., and McIntosh, R., Ibid.,31, 84-90 (1953). (88F) Stetsenko, A. I., and Tverdovskil, I. P., Zhur. Fiz. Khim., 26, 647-58 (1952). (89F) Suhrmann, R., Z . Electrochem., 56, 351-60 (1952). (90F) Tanaka, Yoshio, and Sakai, Masatoshi, Science of LiQht (Japan), 1, No. 2, 93-7 (1951). (91F) Theimer, Otto, Nature, 168, 873 (1951). (92F) Theimer, O., Trans. Faraday Soc., 48,326431 (1952). (93F) Tompkins, F. C., 2.Electrochem., 56,360-3 (1952). (94F) Utsugi, Hiroshi, J . Chem. SOC.Japan, Pure Chem. Sect., 73, 232-4 (1952). (95F) Ibid., pp. 450-3, 917-20. (96F) Waarden, M. van der, and Scheffer, F. E. C., Rec. trav. chim., 71, 689-98 (1952). (97F) N7hite, David, Chou, Chien, and Johnston, H. L., J. C h e n . Phys., 20, 1819-20 (1952). (98F) Wylie, R. G., Australian J . Sci. Research, A5,288-302 (1952). (99F) Yamada, Tadashi, and Kajits, Shigeru, Kagaku, 23, 312-13 (1953). (100F) Young, D. M., Trans. Faraday Soc., 48, 548-61 (1952). (101F) Zettlemoyer, A. C., Young, G. J., Chessick, J. J., and Healy, F. H.. Dresented at 27th National Cotloid SvmDosium. Ames, Iowa, June 1953. I
-
CENTRIFUGATION 1. 0.MALONEY UNIVERSITY OF KANSAS, LAWRENCE,
KAN.
Increasing interest in centrifugation is shown by a half-day meeting on centrifugal theory and practice which was held during the past year, and the scheduling of a symposium on this unit operation for the coming year. Further studies on the fundamentals of centrifugal Filtration have been reported by workers here and in England. Additional pilot plant facilities are being developed by manufacturers of centrifugal equipment for the use of prospective customers.
T
HE topic of centrifugation has been treated in several general books on chemical technology. Riegel (46) has issued a second edition of his “Chemical Process Machinery,” in which somewhat more attention is given to centrifugal equipment than in his first edition (@), but the section tends t o lack balance and definitiveness. This is exemplified by the limited consideration given the Bird centrifugal, the omission of any discussion of the DeLaval units, and a failure to give sufficient information to permit the reader to differentiate between the Ter Meer filtering centrifugal and the Sharples Super-D-Hydrator or between certain Bird and Sharples units. All this may tend to confuse the uninitiated, In “Chemische Technologie’’ (70) there is a brief section on the subject, including a novel ilIustrated table of centrifugal equipment. Another book, under the somewhat deceptive title of “Filter Manual” (r), gives details of construction, installation procedure, operating methods, and maintenance considerations for a solid-
bowl centrifuge. Well illustrated and clearly written, i t is the authoritative work on this centrifuge. A review of the principles of sugar wringing ha5 been presented by Honig (33) who includes some general statements regarding the effect of certain variables on the removal of molasses from sugar. A number of review articles have appeared. The best written and most analytical article by Ruegg (4R) describes four types of machines, the vertical perforate basket unit, the scraper centrifuge, the screw-type discharge unit, and the push-type centrifuge. Ruegg states the limitations of the various kinds of units and presents their advantages and disadvantages. Dolton (16) has written a general descriptive article on the Sharplea-DeLaval type units, but unfortunately, his illustrations of equipment were made for a much more detailed treatment than he gave. This makes for confusing reading. The most interesting portion of the paper is the question section a t the end of the work. The questions, together with Dolton’s answers, are examples of the information which is of interest to chemical engineers. An extensive and well-written review article on the subject, prepared by Broadwell (9) gives an especially good treatment of recent British and Ameri-
-
January 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
can patents. Van Riel (68) has presented for the Dutch engineers an extensive description of centrifuges. Its principal interest to the American reader will be the information on continental centrifugal equipment. Gillis (60) has described the applications of centrifugal separators to mineral dressing operations. Goodwin (23) tells of the use of centrifugals in modern sugar refining. Three review papers appeared on a program devoted to centrifugation. The first (38) by the reviewer, covered the present state of the theory of centrifugation, and treated centrifugal sedimentation, centrifugal filtration, and crystal wringing. Crandall (14) described the various types of basket centrifuges, drives, sizes, and controls. Continuous-type centrifugation equipment was covered by Stahl (62). The problem of maintenance and cleaning of centrifugal equipment is of continuing importance. Dalziel (15) discusses the reasons for basket failure in the sugar industry and recommends certain precautions and materials. A reconditioning procedure for centrifugal baskets which have been coated and clogged with dried lacquer is recommended (63). Illustrated instructions for cleaning the disk-type and tubular bowl centrifuges are available
73
that the larger the sugar crystals the less is the quantity of molaases left on them, and the shorter the wringing time necessary. For a sugar of uniform grain size there is not too much advantage in slow acceleration. If a t all possible, operation to produce a uniform grain size is desirable.
(17).
FUNDAMENTAL STUDIES Ambler (6)has gone beyond the procedures advocated by him (4)in 1952 and by Hebb and Smith (38) in 1949 in the scaling up of centrifugal equipment. He states that scale-up procedures for tubular bowls in which solid particles are settled out follow the theoretical equations rather well, but that the performance of disk-bowl units is somewhat below that predicted by the theory. He gives precautions to be observed when scaling up such e q u i p ment. He next develops equations for the separation of two immiscible liquids in the tubular and the disk-type bowls. H e then considers the conical and cylindrical types of solid bowl centrifuges and says that a reasonable comparison exists between the performance of laboratory and large scale units. At the end, he gives a numerical example of the procedure employed to predict the performance of a Sharples Super-D-Hydrator from tests on a centrifuge 12 inches in diameter. This is one of the few such examples in the literature. The inclusion of test data on the large scale and small scale units would have been most welcome. Stevens (66) has reported on the performance of high speed centrifugals in the sugar industry and the factors that influence their efficiency. One point he makes in connection with the centrifugation of final crystallizer massecuites of mixed grain size is that unless the acceleration of the centrifugal is gradual, a densely packed layer of sugar against the screen may develop, and prevent proper molasses elimination. This situation has long been recognized in filtration practice. A later report (63) shows
Table
1.
New Equipment Developments in Centrifugals
Name Application Manufacturer Continuous centrifugal Crystal drying Baker Perkins (design modifications) Broadbent Sugar wringing Broadbent Gyro tester Laboratory and pilot DeLaval plant studies Citrus juice clarifier Processing of fruit DeLaval juices Model VO-194 Air-tight refining of DeLaval DeLaval vegetable oils Glacier-Metal Co. Centrifugal oil filter Automobile oil Continuous centrifuge Sugar centrifugal Krauss-Maffei Model30 Merco Gluten and primary Merco starch separation Continuous solid-bowl Variable speed on Tolhurst conical conveyor allows flexibility Automatic recycling High capacity heavy- Western States machine duty crystal wringMachine Co. ing Regenerative braking General European developments
..... .....
..... .....
Reference (57) (18)
COURTESY BIRD M A C H I N E CO
Centrifugals at Duval Potash and Sulphur Corp., Carlsbad N. Mex., Handle Concentrated Potash from Flotation Cel js
During the past 12 months six papers by Haruni and Storrow have appeared (26-31), all concerned with hydroextraction. Earlier Storrow et al. (1 I , 35, 56) had reported a lack of reproducibility in centrifugal experiments, and that in hydroextraction the filtration rate did not seem to follow their basic equation. I n the first three papers of the new sequence they have modified their operating techniques and have established the fact that their equation satisfactorily represents the centrifugal filtration of precipitated chalk, barium sulfate, and starch. They investigated essentially every term and combination of terms in their equation, including viscosity and basket size. In subsequent articles they discuss the radial distribution of permeability in cakes (66). the pressure distribution ( Z ? ) , and the effect of a nonvertical cake (88). In summary, this work is the most extensive that has been done and represents a basic contribution to the field. Grace (24) has developed a formula similar to Storrow's on centrifugal filtration. Some of his experimental data seem somewhat a t variance with the data of Storrow. He speaks of radial cracks developing in his cakes, which leads one to suspect that his cakes were allowed to become dry. In the experience of Storrow and the reviewer, this drying action causes such significant changes in the filter cakes as to make the data difficult to interpret.
(40) (40)
NEW EQUIPMENT
(40)
The principal developments known to the reviewer are presented in Table I. A number of centrifugal manufacturers are establishing special pilot plant facilities or are making available units for pilot plant studies by prospective users. The Bird Machine Co. announced several years ago its new research and development center. The DeLaval Separator Co. (40) has recently set up for the use of industry a pilot plant for studying vegetable oil refining. Merco (43) has a plan for renting pilot plant units to potential users. Baker Perkins (37) is issuing a detailed description of modifications made in the design
(61)
(IO)
(4a
(68)
(44)
(88)
INDUSTRIAL A N D ENGINEERING CHEMISTRY
74
of its Ter Meer units as well as more extensive information on the centrifugal dryer and concentrating screw feeder.
APPLICATIONS Table I1 shows recent applications of centrifugal equipment to the process industries.
Table II. Applications of Centrifugal Equipment Manufacturing Process Type of Unit Materials Separated Potassium chloride Bird Potassium ohloride from sodium chloride Fine size calcium oarBird Classification of calcium bonate carbonate Cement Bird Classification of cement fines Coal cleaning Bird Ash from coal Citrus fruit juices DeLaval Pulp from juice Isolation of wool grease DeLaval Wool grease from scouring liquor Fermentation liquors DeLaval Yeast from wort Yeast from alkaline soluBrewer’s yeast DeLaval tion Lubricating oil . llerco Black-acid sludge from oil Heavy chemicals Merco Alum and phosphate liquor Plastics Merco Washing and concentrat-
Sou0 stock
hIerco
Residual oils Crude oil Natural fat Tar from cake ovens and water gas operations Sugar Varnishes Yeast molasses
Sharples
Sharples Sharples
Sharples Ter Meer ...
...
and clays
Removal of solid matter from beef extract Ash and mineral matter from residual fueh Cleaning of crude oil before burning in engines Fat and water from solid material, fat from water Moisture from tar Sugar from molasses Solids from varnishes Yeast from molasses
(6) (6)
(6)
(6) (49) (48)
(18)
RECENT PATENTS The following patents have come to the reviewer’s attention. iluger-type continuous centrifuge (18) Automatic centrifugals (66-68) Automatic feed for centrifugals (61) Centrifugal dewaxing (38) Centrifugal extractor (64,69) Centrifugal separator (1, 18, 41) Centrifuge tube (56) Centrifuging massecuite (34) Continuous centrifugal (67, 64) Discharge plow for centrifugals (8) Funnel for centrifuge (60) Horizontal centrifuge (21) Mineral slurry separation (47) Separating by conbined filtration and centrifugation (3) Spinning can (68) Yeast separator (36) Vertical continuous centrifuge (3)
LITERATURE CITED (1) Adams, J. S., and Wilson, P. E., U. S. Patent 2,646,921 (July 28,
1953). Sktiebolaget Separator, Brit. Patent 670,260 (April 16, 1952). Alekseenko, M. K., Russ. Patent 77,082 (Dec. 31, 1949). 48, 150-8 (1952). Ambler, C. M., Chem. Eng. PVOQT., Ambler, C. M., Reprint, New Jersey Section Meeting, Am. Inst. Chem. Engrs., May 5,1953. (6) Ambler, C. M., Sharples Corp., private communication, Oct. 12,1953. (7) Bird Machine Co., South Walpole, Mass., “Bird Filter Manual,” 1953. (8) Broadbent and Sons, Ltd., T., Brit. Patent 674, 276 (June 18, 1952). (9) Broadwell, E., Chem. &Process Eng., 34,78-82 (1953). (10) Buddberg, W., Sugar, 48, No. 10, 40, 42 (1953). (11) Burak, N., and Storrow, J. A , , J . SOC.Chem.:??nd. (London), 69, 8 (1950). (2) (3) (4) (5)
Vol. 46, No. 1
(12) Chem. Age, 59,419-20 (1953). (13) Chem. & Process Eng., 34, 288-90 (1953). (14) Crandall, W. C., Reprint, New Jersey Section Meeting, Am. Inst. Chem. Engrs., May 5, 1953. (15) Dalziel, H. R., Proc. Queensland SOC.Sugar Cane Technol., 1953, 65 -75. (16) Dolton, R. H., SOC.Chem. Ind. (London), C h a . Eng. Group Proc., 33,l-9 (1951). (17) Elonka, S., Power, 97,112-3 (1953). (18) Feifel, E., Austrian Patent 172,637 (Sept. 25, 1952). (19) Finkelshtein, G. A., and Pliss, D. A., Russ. Patent 74,644 (Dec. 31, 1949). (20) Gillis, J. J., “Centrifugal Separators in Mineral Dressing,” Bird Machine Co., South Walpole, Mass., 1953. (21) Gladkov, V. F., Russ. Patent 77,992 (Deo. 31,1949). (22) Gothel, H., and Meissner, H., Chem. Ing. Tech.,24,704-7 (1952). (23) Goodwin, R. F., Intern. Sugar J., 55, 180-1 (1953). (24) Grace, II. P., Chem. Eng. Progr., 49,427-36 (1953). (25) Hanne, T. V., U. S. Patent 2,631,777 (Maroh 17, 1953). (26) Haruni, M. M., and Storrow, J. A,, Chem. Eng. Sci., 1, 154-64 (1952). (27) It~id.,2,’108-19 (1953). (28) Ibid., pp. 164-72. (29) Haruni, M. M., and Storrow, J. A., IND. EN^. CHEM.,44,2751-6 (1952). (30) Ibid., pp. 2756-63. (31) Ibid., pp. 2764-7. (32) Hebb, M. H., and Smith, F. H., in “Encyclopedia of Chemical Technology,” Vol. 3, pp. 501-21, New York, Interscience Publishers, 1949. (33) Honig, P., “Principles of Sugar Technology,” pp. 437-41, Amsterdam, Elsevier Publishing Co.. 1953. (34) Hoyt, S. T., U. S. Patent 2,643,960 (June 30, 1953). (35) Inglesent, H., and Storrow, J. A., Ind. Chemist, 27.76-81 (1951). (36) Kirchner, Carl, A.G., Swiss Patent 278,637 (Jan. 16, 1952). (37) Mack, K. A., Baker Perkins, Inc., private communication, Oct. 20, 1953. (38) Maloney, J. O., Reprint, New Jersey Section Meeting, Am. Inst. Chem. Engrs., May5, 1953. (39) Marumo, Hideo, Japan. Patent 6188 (Oct. 15, 1951). (40) Meystre, F. J., Jr., DeLaval Separator Co., private communicacation, Oct. 19,1953. (41) Nordstrom, O., Swed. Patent 136,300 (July 1, 1952). ,(42) Poggi-Lollini, A,, Pitture e vernici, 8, 311-6 (1952). (43) Pomeroy, H. H., Merco Centrifugal Co., private communication, Oct. 23,1953. (44) Pulles. P. C. W.. Inoenieur. 63. No. 42. 59-62 iOct. 26. 1951). {45j Riegel, E. R., “Chemical Machkery,” pp. 299-314, Xew York, Reinhold Publishing Corp., 1944. (46) Riegel, E. R., “Chemical Process Machinery,” pp. 367-89, New York, Reinhold Publishing Corp., 1953. (47) Ritsch, Howard, U. S. Patent 2,614,748 (Oct. 21, 1952). (48) Ruegg, E., Chem. & Process Eng., 33, 663-7 (1952). (49) Ruegg, E., Zucker, 5,548-51 (1952). (50) Schneider, J. A,, Western States Machine Co., private communication, Oct. 23,1953. (51) Sci. Lubrication, 4, No. 10, 23-4, 33 (1952). (52) Stahl, P., Reprint, New Jersey Section Meeting, Am. Inst. Chem. Engrs., May 5,1953. (53) Steel, 129,112-3 (Oct. 15,1951). (54) Steinacker, P., and Hemfort, H., U. S. Patent 2,622,796 (Dec. 23,1952). (55) Stevens, G. E., “Advantages of High Speed Centrifugals in the Sugar Industry,” Western States Maohine Co., Hamilton, Ohio, 1948. (56) Storrow, J. A., and Zychlin, H., J . Soc. Chem. Ind. (London),69, 379 (1950). (57) Utkin, I. S., Russ. Patent 77,054 (Dec. 31, 1941). (58) Van Riel, P., Ingenieur, 64, No. 9, 11-18 (Feb. 29,1952). (59) Vereinigte Glanzstoff-Fabriken, A.G., Ger. Patent 813,745 (Sept. 17, 1951). (60) Ibid., 813,748 (Sept. 17, 1951). (61) Watson, Laidow& Co., Ltd., Brit. Patent 683,711 (Dec. 3, 1952). (62) Weicker, F. C., Tolhurst Centrifugals, private communication, Oct. 13. 1953. (63) Western States Machine Co., Hamilton, Ohio, “Advantages of Regulated Acceleration Rates,’’ 1952. (64) Western States Machine Co., Brit. Patent, 675,417 (July 9, 1952). (65) Ibid., 688,707 (March 11, 1953). (66) Ibid.,688,712 (March 11,1953). (67) Ibid., 688,713 (March 11,1953). (68) Ibzd., 688,722 (hlarch 11,1953). (69) Westfalia Separator A.G., Ger. Patent 819.977 (Nov. 5, 1951). (70) Winnacker, K., and Weingaertner, E., “Chemische Technologie,” pp. 85-8, Xunich, Carl Hanser T’erlag, 1950.
,
1
