FILTRATION S. A. MILLER UNIVERSITY OF KANSAS, LAWRENCE, KAN.
The outstanding achievements in filtration for the past year were made in the realm that i s often called theoretical but is actually experimental and mathematical. The validity of designing filters and centrifugal filters on the basis of permeability compression cell data has been established, an accomplishment the importance of which is difficult to overstate. Serious research is being directed toward the porosity and structure of filter cakes. The filtration of wood pulp and the dewatering and conditioning of sewage sludge have received careful attention. Terylene filter cloths and Dyne1 felts have been added to the family of synthetic mediums, and a filter aid derived from coal now is available. Detailed descriptions and some data have been published for precoat pressure leaf filters and micronic clarifying cartridges.
P
a t London’s first postwar Chemical Plant Exhibition @A, 16A) have been written. A new French book (SA) came to the attention too late, unfortunately, for inspection and proper comment this year.
THEORY, EXPERIMENTAL DATA, AND DESIGN METHODS
UBLICATIONS on atration last year took the variety of forms customary for a unit operation of long established art, still incomplete theory, and widespread and industrially heterogeneous use-reports of researches, descriptive accounts of apparatus, spots of operating data and description of processes directed to a special industrial colony, patent specifications, laboratory procedures, and commercial broohures. A notable difference, however, lay in the relatively large number of research papers-dealing with the mechanics and mathematics underlying filtration, and attempting sounder correlations and surer methods for design and operation. Because of the space required for proper attention to these contributions and because the reviewer was unable this year to survey conscientiously the issue of industrial literature, for the first time in seven years this review reports no catalogs or trade bulletins. This is not a happy omission, nor is it intended as a precedent. In view of the increasing number of patents and the reviewer’s difficulty in discovering and assessing all that issue, another departure has been made. With a few exceptions, patents are neither discussed nor listed in the literature cited; instead a table has been prepared giving the patentee country, number, a brief title and the date of issue for those patents relevant to filtration that the reviewer has noted. The scope of the review otherwise is that of previous ones of the series, covering conventional filtration for the period ending October 1953, and excluding gas clarification, centrifugal and sedimentary separation, adsorptive percolation, and biofiltration.
The advent of the “Chemical Engineering Fundamentals Review” has removed any obligation that this reviewer may have felt to refer to work being done in the broad area of fluid flow and mass transfer within granular beds and capillary passages. The reader concerned with the abstract aspects of such flow phenomena is referred to the excellent summary by Baron and Oppenheim (1A) and to others that will follow in the series. On the other hand, deeper insight is needed in the area of direct application of physical and mathematical fundamentals to a phenomenon as individual as filtration; and as specific research lends such insight and provides more legitimate design and operating procedures, it is proper that it be noted in this review. Several extremely important papers of this character which appeared last year, therefore, will be mentioned. Publications of Carman and Ruth several years ago drew attention to the similarity between bed permeability measurement and filtration and brought the Kozeny equation to the notice of chemical engineers. Since then, increasing study has been directed toward the quantitative examination of bed structure and its relation to filtration resistance. Nearly all of the papers to be cited in this sectioo have this viewpoint. Tiller (2SA) made a detailed mathematical analysis of the Kozeny-Carman equation and applied it to constant-rate and constant-pressure filtrations of simple and compound compressible systems. By use of an empirical compressibility relationship-Le., relationship between cake porosity or compression and the compression stress-he was able to integrate graphically the equations for the various cases studied. He assumed that the Kozeny coefficient and the bed specific surface are constant, a mooted point. He did not test his equations with experimental data. Grace (6A) also derived a form of the Kozeny equation, applying it first to static beds in which the compressive stress could be controlled, similar to Ruth’s method. Assuming Kozeny’s coefficient is 5 (for random packing), he inferred the bed specific surface from permeability determinations and found that it agreed with particle specific surface for unflocculated systems of properly packed smooth particles, but did not agree for flocculated systems. He concluded that tho Kozeny equation cannot be evaluated properly from particle properties. Particle size, he pointed out, influences bed resistance principally through its influence on the degree of flocculation. In a second excellent paper ( 6 8 ) Grace derived equations applicable to pressure filtration. determined the filtration resistance by permeability measurements and by actual pressure filtrations, and compared the two. They agreed within &lo%. His data are extensive and careful, covering many systems of varying degrees of flocculation and compressibility, and they constitut~a
REVIEWS For the second successive year, Streatfield (d2A) prepared a noncritical but good review of recent filtration papers, including 35 British patents. He placed major emphasis on water and wastes, citing 30 references in this area. Heertjes (11A) surveyed the status of filtration understanding and commented on the inadequacy of present theory, particularly with respect to cake structure and compaction, Heinrich (23%) reviewed the fltration equations applicable to sugar refining. Two new books (15A, 18A) included brief, superficial treatments of filtration equipment. Riegel’s second edition (18A) has an enlarged and improved chapter on filters that is still not without errors and has an unfortunate tendency to use trade names typically. Lauer and Heckman (15A) made illustrative allusion to only a few types of filters. Waeser (25d) gave a synopsis of the history of filter developments in Germany with mention of the practice of several different industries with respect to filters and other solid-liquid separators, while von der Heide (12A) described many clarifying filters of German, British, and U. S. manufacture. Brief accounts of the filters and accessories displayed a t Frankfurt’s ACHEMA X in 1952 (4A, W4A) and
100
January 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
beautiful validation of the applicability of permeability data to filter design. Incidentally, Grace inferred that neither the Koaeny coefficient nor the bed specific surface (particularly the latter) is constant throughout a filtration. Ingmanson (14A) conducted experiments similar t o those of Grace, using beaten and.unbeaten pulp durries. His permeability and filtration resistances for dilute slurries agreed fairly well, but the values for concentrated slurries did not. This is not remarkable in view of the simple compressibility relationship which he assumed, the high degree of flocculation probable, and the complicated physical chemistry of the water-pulp system. Rietema (19A),in a paper based on his doctorate thesis (%OA), reported experiments with a cake made up of 5- to 12-micron polyvinyl chloride particles, He measured the pressure gradient along the cake by a family of manometers and the electrical resistance of cake, taking the latter as an index of porosity. He observed a phenomenon of local compaction-which he termed “retarded packing compressibility”-at the bottom of the cake; it occwrred only after a certain critical cake thickness had been achieved. Rietema was unable to explain the phenomenon except generally as a manifestation of cake structure instability related, he conjectured, to electrokinesis. Ralff (8A) studied the filtration of flocculated sewage sludge and attempted to formulate a filtration equation based on the pirmise that the portion of the externally applied pressure carried by the solids varies inversely as the mass ratio of liquid to dry solids in the cake, a ratio which is assumed to have an equilibrium value fcr a given cake pressure, and on the assumption of a coefficient of compressibility slmilar to Terzaghi’s. The resulting equation was of the Fourier type. Although he showed agreement between his experimental and calculated values, the generality of his method is doubtful. Shekhtman (21A) proposed a similar relationship to describe the concentration of a suspension during its filtration. The filtration phenomenon occurring in a centrifugal field, after much work by Storrow and coworkers, has a t last been defined. Haruni and Storrow (IOA) derived equations for centrifugal filtration in terms of a permeability coefficient. In a number of careful experiments, they made permeability and filtration nieawrements in both centrifugal and noncentrifugal fields. The permeabilities of formed cakes agreed well in both fields; pressure filtration data differed by some 15%, however, from centifugal filtration data, Grace ( “ A ) derived similar equations and observed similar near agreement between centrifugal-filtration resistance and that measured in a permeability compression cell, Haruni and Storrow (Qd)failed in an attempt to shorn perceptibly variable porosity in the radial direction within a centrifuge cake and concluded that the layer between cake and medium in the centrifuge was characterized by extraordinarily high resistance. Wrist (16A) studied the drainage of pulp on a Fourdrinier n m , proposed that the major driving force producing drainage results from the interaction of the wire, a supporting roll, and the water in the nip between the two, and derived equations for flow on this basis, The equations are supported by data, and Wrist suggested that they will permit the investigation of pulp filtiation resistance in terms of pulp properties and machine operating conditions. Orlicek and Schmidt (17 A ) presented a nomograph for computing optimum dilution for filtration of a viscous liquid.
EQUIPMENT AND ITS OPERATION I’ressure leaf filters with mechanical sluicing sprays for cake removal Fere discussed in detail by Ulrich (19B). He pointed out the advantages, limitations, and proper application of this type of filter, with particular reference to the Kiagara, emphasizing its amenability to automatic-cycle operation. Forster f?B) also wrote of the precoat pressure leaf filter and its advan-
101
tages. giving typical dimensions and operating data on sugar liquor. The English Metafilter (QB),an established precoat filter, and an American precoat unit employing porous stone elements (4B) were described briefly. Of two new German pressure filters reported, one was a jacketed-shell horizontal plate machine (21B),while the other was a small scale filter embodying concentric cylindrical sections to provide large filtering area per unit of floor space (17B). A Russian filter press has been equipped with a hydraulic closer (1OB). Schwob (16B) pointed out that efficient washing on a rotary vacuum drum demands a cake of constant thickness, and he suggested that slurry be fed to the filter trough from a constanthead tank to ensure a uniform feed rate; with such a device he claimed 96% filtrate displacement with 120% of theoretical wash. A cellular filter band passing over the filter drum to assist cake washing was described by Weinhold (.%?OB). Kilby (11B) and Pollman (ISB)dealt with the problems of a turbid filtrate from continuous vacuum filters in the sugar mill, suggesting several methods of filtrate clarification. Filter presses, Pollman concluded, are awkward and labor expensive, whereas sedimentation is more appealing; the use of a centrifuge, moreover, has been suggested (1B). An in-line strainer (SB) and a rotary drum screening filter (5B), both back-washing, were described. Lubrication and care consistent with good maintenance of the latter type were outlined ( l 2 B ) . Other filters likely to be used for water also were discussed (6B, 8B, I4B); these included a polishing station consisting of one or more anthracite-bed pressure filters each equipped with a built-in water-driven rake (6%); rapid sand filters of improved design (14B); and the Hardinge multi-compartment automatic washing sand filter (BB). Roe (15B) and Berkeley (2B) explained the use and advantages of porous ceramic-plate underdrains and spelled out some precautions regarding their installation, which costs $5 to $7 per square foot. Tong (28B)mentioned two simple but interesting homemade filters said to be useful in small overseas-Le., isolated-power plants for oil filtration. The first was a candle filter made from a perforated pipe capped a t the end and wound with string of selected appropriate size. The second was a box of sheep’s wool for demulsifying and removing water; the wool layer should be not less than 1 foot deep and should sustain a pressure drop less than 1.5 pound per square inch. Table I lists some patents on filters that have recently appeared.
.
PROCESS APPLICATIONS SUGAR
Of the numerous publications on the filtration and clarification of sugar, only some of which are cited in this review, several were devoted to the use of the continuous vacuum filter. Nesvadba (46C) and Saha and coworkers (10B) summarized the advantages of the rotary vacuum filter. Power requirement and capacity data were reported (46C), and the general rules for successful operation stressed (58C). Conditions of optimum efficiency were studied by Madon (QOC), who emphasized the role of bagasse. The most successful use of vacuum filters in middle juice carbonation was shown to depend heavily on such process items as recycling part of the unfiltered first carbonation juice and treatment with optimum of lime (6SC). Other reports (sac, 66C) on plant experience with vacuum filters were published. A paper on the use of Sweetland presses and the regeneration of kieselguhr, mentioned in the last filtration review, has been extensively abstracted (2C). Meade (4SC) discussed pressure filtration and filter aids in connection with defecation, but expressed doubts about the advantages of pressure filtration over phosphate-lime defecation followed by use of the Williamson clarifier. Kortschak (S8C) pointed out that insoluble solids of the order of 1 micron occluded in raw sugar crystals, rather than gums and colloids, are the chief contributors to low filtration rates.
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
102
Table 1. Patentee Carrigan, R. E . Heftler M. B Alexander, L. 'G. Robinson, M . C. Valente, J. E. Howland, E. H., and Temer, R . G . Ross M Kraiklaier, A. C. Wright A. Fischer: K . A. Koupal, R. J . Kovacs, J. P. Kracklauer, 8. C. Miller C. F and Willer, A. Mack,' K. A:' Vocelka, J. Pellas, S. F., and Kraut, M. Simpson A J., and Bwicky, J. F. Biggar i.H. Rogers: J. E. Cording, J., Jr., and Shaines, A. Schwartz, D. M. Wittington P. E. Depallens, i. Garland, C. e., and Rogers, F. H . Little, J. W. Hansen. K. H . Delattre, D. Cairns J. Friedei, F. A , , and Friedel, F. -4., Jr. Auto-Klean Strainers, Ltd. Renner, B., and MUller, E. Stauffer, K. Peutsche Edelstrrhlwerke A . 4 . and Chemaperm G .m. b ,H , Yaeawa, M. E:son, 9. E. Richter, J. C. F. C. Lindblad K. R. Zucker j CIBA, 'Ltd.
Country
White, C. N. Crawley W. P Taylor W.I. i n d Grebby J. W Gurnick, R. S . , and Joy, R'. T . Wicks J. D . E. Bell Layie, R.R., and Bell, A. E. Rauter, H . Ebert, L., and Haller, W. Ishigaki, Y.
u. 8.
u. s.
British DanLh German
Japan Swedish Swim
A
Austrian Japan
u. s.
Patents Relevant to Filtration Patent
No.
2,600,845 " 2,601,521 2,604,992 2,606,149 2,607,495 2,609,933 2,609,101 2,615,574 2,615,575 2,617,763 2,620,927 2,622,738 2,624,465 2,626,229 2,631,527 2,631,732 2,633,243 2,633,990 2,653,893 2,636,611 2,636,612 2,637,443 2,640,026 2 641 364 2:642:186 688,255 75,782 808,828 809,769 809,799 815,485 816,850 817,752 820,085 4261 ('51) 136,982 137,446 139,026 270,247 280,822 2,611,750 2,615,477 2,620,283 2,622,024 2,627,350 2,642,187 2,642,188 173,461 174,611 3210 ('52)
Tiedje J L. N. L. Rodrnkn ' C. A. and Tewksbu H. Kiersted' W J r . and Gross Rodman: C . ' k . , rand Tewksdury, N. L. Stewart, C. R. Farrell, L. S. Kempe, R .
German
2 , 6 0 8 , 517 2,609,931 2,612,466 2,613,813 2,617,719 2,621,156 817,446
Ohkraivara, N.
Japan
3124 ('50)
g'
Vol. 46, No. 1
A new book ($87) by Honig and many collaborators includes numerous references to filtration in sugar refining. A brief description (69C) of research at Louisiana State University's experiment station mentions projects on filtration and clarification problems. BEVERAGES
Geiss (ZZC), in a handbook of wine filtration, offered much practical information on filtration technique with emphasis on the careful removal of microorganisms. Fessler (19C) disclosed a composite filter devised to effect high clarity in wine. Hauptmann (WC) investigated the action of filtration enzymespectase and pectinase-on the albuminous substances in fruit juices and their beneficial influence on filtration. Pinkerton (5%C) reviewed the importance of the proper care of filtermasse when it is used for beer polishing, and a general report (BOC) on the status of brewing technology contrasted Bmerican and European practice with respect to trub removal and mentioned the use of diatomite filters for final filtration. ELECTROPLATING AND MINERALS
The filtration of electroplating solutions has been discussed extensively in papers by Colegate (6C-10C) and Modjeska and Faint (43C). Filtration helps prevent porosity, particularly when high
Equipment Liquid filter Metal-edge filter Filtering unit Filter strainer Filter unit Filter with coiled-spring medium Filter with automatic washing device Horizontal plate filter Continuous drum filter Electrostatic filter for dewaxing oils Sand filter arranged on annular trays Edge filter with tubular helix Horizontal plate filter Electrically controlled still and filter Rotary filter press Fiber disk filter assembly Filter and clarifier of sugar juice Water-filtering a paratus Rotary vacuum &ter with endless belt Wire tensioner for rotary filter Rotating filter screen and scrapers Rotary pan filter Combined electrical and mechanical filter Filter with steam or air cleaner Multiple-layer filter Continuous rotary filter Apparatus for continuous filtering of solutions Extraction and filtering apparatus Filtering apparatus Improved filters with magnetic field Platelike filter with steplike cylindrical surface Filter for clarifying beer wort Filter for treating liquids and gasFilter for liquid with ferromagnetic particles Apparatus for filtering solutions Filters for fibrous suspensions Rotary vacuum filter Rotary filter for cellulose suspensions Filter Support for tubular filter Filter Mediums and Cartridges Porous thermosetting resinous filter medium Filter medium of vinyl resin yarn Fibrous filter media Controlling the density of sintered compacts Filter cartridge Filter unit construction Replaceable filter unit construction Filter aggregate for continuously filtering liquids Porous bodies, especially filters Filter bed for liquid fuel Processes and Methods Dewaxing process using a filter aid Filtering oils Wax filtration Filtering sludge Cleaning porous mediums Method for feeding filter aid Process and apparatus for leaching substances with filtration of the liquid mixture Filtering sodium alginate
Date June 17 1952 June 24' 1952 July 29 ' 1952 Aug: Aug 518,'1952 1959 Sept. 2 1952 Sept 9'1952 Oct.'28' 1952 Oct. 28: 1962 Nov. 11, 1952 Dec. 9, 1952 Dec. 23 1952 Jan. 6, i s 5 3 Jan. 20 1953 March i 7 1953 March 17' 1953 March 31: 1953 April 7 1953 April 7' 1953 April 28 1953 April 28: 1953 M a y 5, 1953 May 26. 1953 J u n e 9 1953 June l b 1953 March 1953 March 4: 1953 July 19, 1951 Aug. 2 , 1951 Bug. 2 1951 Oct. 1,'1951 Oct. 15, 1951 Oct. 18, 1951
t
4
Nov. 8, 1951 Aug. 2 1951 Aug 18 1952 Sept'. 23' 1952 Feb. 3, i s 5 3 Nov. M a y 1, 16,1952 1950
Sept. 23 1952 Oct. 28, '1952 Dec. 2, 1952 Dec. 16, 1952 Feb. 3, 1953 June 16, 1963 June 16 1953 Dec. 27' 1952 April 26, 1953 hug. 22, 1952 Aug. 26 1932 Sept. 9,'1952 Sept 30 1952 Oct. '14 '1952 NO>-. ii 1952 Dec. 9, i s 5 2 Oot. 18, 1951 Sept. 30, 1950
current density is involved, and permit3 bath agitation (6C). Proper use of precoat and proper circulation rate in continuouR filtration are important (YC, 432). A variety of materials are used as filter fabrics, including asbestos, cotton, wool, glass, and synthetics (8C). Although plate and frame presses can be used, precoated pressure leaf or pulp sheet filters are preferred (QC, 4 3 3 . Colegate concluded his series of papers with a discussion of pumps used in electroplating practice (IOC). An interesting paper on the scale-up of vacuum filters for coal dewatering by Piroe, Brusenback and Dahlstrom, reviewed last year, now has been published (633. Fine coal is succesFfully dewatered-cake has 25 to 30% moisture-by a shaking screen discharging on a porous belt that passes between rolls, it has been reported (85C). This extraordinary substitute for a vacuum filter was developed as part of a small portable plant. Data for the handling of coal flotation tailings in a recessed plate filter press have been presented (14C); filtered a t constant rate to a final pressure of 100 pounds per square inch gage, the cake contained 17 to 22% moisture. The filtration of clay has been described (17%') by an equation admitted by its authors to be incorrect, but said to be satisfactory for portions of the filtration cycle. The performance of an Edco vacuum thickener operating in leach liquor was included in a report of anelectrolytic zinc process(45C). The removal of impuri-
~
January 1954
I N D U S T R I A L AND E N G I N E E R I N G CHEMISTRY
ties, principally kaolin, from potassium nitrate liquor was investigated by C'hodkiewicz (6C), who compared sedimentation, froth flotation, and sand and filter-press filtration. Filtration was unfavorably slow. MISCELLANEOUS PROCESSES
An extremely interesting process known as filtration extraction, using a horizontal rotary vacuum filter, was developed by the SGuthern Regional Research Laboratory (21C). Detailed data TTere reported on its successful application to cottonseed (12C) and rice bran (24C). The meal was separated from rich miscella and subsequently extracted thrice countercurrently on the filter. Continued study of the filtration of viscose was evidenced by two more papers (@E, 57C) discussing some factors affecting the filterability of spinning solution, among them high speed agitation (49C). A disclosure was made of a method for continuously filtering a high viscosity cellulose ester solution on a backwash filter (4C). Equipment and procedures for straining paints and clarifying lacquers and varnishes were described in two papers (232, 64C). The use of a crystallizing agent (MEK) to consolidate a slush of wax in oil into a filterable mass of crystals was patented (IC). WATER, SEWAGE, AND INDUSTRIAL WASTES
Papers by Powell (65C) and Xeufield (47C) described granular bed (sand or anthracite) filters with directions for their packing and many admonitions about their proper care and operation. Slow sand filtem were successfully speeded up, according to Dean ( I S C ) and Karalekas (SSC), when either the turbidity of the feed was lowered or when it became unnecessary to rely on the sand filter for bacteria removal. Oliver (60C) reported difficulty with mud balls and tastes, difficulties he concluded were best avoided by preliminary filtration. Engler (18C) mentioned the use of sand-and-gravel roughing or preliminary filters as limited chiefly to The Setherlands and England. Gravity sand filters and their operation were described briefly by other authors (bOC, 37C, 41C). Braune (SC) reported favorably on some exploratory observations with filtration through Sterilit, a granular material containing silver, as a sterilization substitute for chlorination. Only a portion of the water need be treated; it is then mixed with the remainder. Hazen (arc)wrote of the use of microstrainers-drums covered with fine mesh screens for preliminary water filtration-in England, and Jenninger (SOC) found that such strainers increased the capacity of succeeding sand filters, particularly when the raw water was very muddy. Interest in microstraining is increasing in the United States ( I l C ) , but there is some skepticism about their usefulness here, particularly for Lake Michigan water (3dC). Similar screem, incidentally, have been installed instead of sewage settling tanks in the Rochester, Minn., disposal plant (442). Special water applications reported were the use of a coarse coke bed 10.6 feet deep to break oil-in-water emulsions and to remove suspended solids from steel mill effluent ( S I C ) ; the use of caustic treatment, followed by pressure filtration, for iron removal in a domestic supply (29C); and the passage of water through precoat pressure filters before its reinjection into oil wells for secondary recovery, to prevent fouling of the sands ( S I C ) . A number of interesting articles on sewage sludge filtration were published. Halff's study of the compressibility of sludge ( 1 4 0 ) already has been mentioned. Eichenlauer and Symons (16C) provided a detailed account of the filtration of sludge dosed with lime and ferric chloride on a 150-square foot SandersonKomline coiled-spring vacuum filter. The importance of proper coagulant use was reported (32C, SSC). Keefer and Meisel (S6C), working with a 9-em. Bdchner funnel, established the superiority of lime-ferric chloride combination and the inferiority
103
of chlorinated copperas to straight ferric chloride. Jepson and Greene (3%') agreed that chlorinated copperae is less effective than the other coagulants, but estimated that it presents a saving of 10 to 14% over ferric chloride; their testa were on semiworks scale. Two papers reported the effect of heat-treatment on coagulation. In a laboratory study, Jepson and Klein (SSC) determined that there is little advantage to using steam pressures gRater than 125 pounds per square inch for longer than 15 minutes when heating activated sludge. They concluded that the dudge filtered more rapidly and to a lower moisture content than it would had it received the optimum dose of ferric chloride without heat treatment. Lumb (39C) reported on a decade of heattreatment on plant scale-25,000 gallons of sludge per day. The sludge is heat exchanged, then steam eparged for 45 minutes to raise it to 360" F. (150 pounds per equare inch), settled overnight and filter pressed to a cake containing 48% moisture. The steam required is 0.64 to 0.96 pounds per imperial gallon, and the cost of treatment in England about 2 shillings 3 pence per metric ton. The successful mechanical filtration of humus tank effluent on sand and anthracite filters was demonstrated (51C) with little difference detected between sand and anthracite and between %foot and greater depths of sand. The removal of radioactive waste by precipitation and collection in a rapid sand filter was reported (16C, 48C). Table I lists a few patents dealing with proceases or methods related to filtration.
FILTER MEDIUMS AND FILTER AIDS Textile production-particularly noncellulosic syntheticscontinues to expand. The U. S. production is nearly 400,000,000 pounds per year and new fibers are still appearing (4D); Canada will have $200,000,000 invested in synthetic fiber plants by 1955, with a $20,000,000Terylene plant to be completed in a year (SD). An excellent review of the rather confusing field of fibers was prepared by Grove and coauthors (IO'D),who pointed out that 32% of all synthetic fibers go to industrial usage-filter cloths, for example-and that economics will determine every fiber's place in industry. Among woven synthetics, Terylene is now being used to some extent as a filter cloth; it is said to last five times as long as wool or cotton ( I l D ) . Dyne1 is available as 20-ounce felt sheet (80). Perlon, a nylon-type fiber, is proving popular for clay filtration in Germany (BOD). Heath (16D) has described the filter-pressing of clay in Britain, where nylon, backed by polyvinyl chloride sheet and gasketed by rubber on the press faces, is widely used. In America synthetic filter cloths can be purchased precut with electrically heated blades that seal the cut edge against raveling (IOD). Van Norden (24D) developed a cerium-impregnated alkali resistant cotton cloth. A Canadian journal (ZD)described the latex-impregnated filter paper mentioned in the last review, contributing no new information. A clever corrugated paper filter element was publicized (14D). Kane (19D) gave a complete discussion of resin-impregnated cellulose-wool micronic filter cartidges, defining their construction, their field of application, and their pressure drop. The versatility of porous metal filters has been praised ( I a D ) , and Pall (2BD) described their manufacture from stainless steel, explaining their use as gas as well as liquid clarifiers. A new all-metal filter ( 6 D ) uses porous elements. Everhart ( I S D ) suggested that porous metal parts can be machined smoothly if the part is first impregnated with a molten solid-e.@;., sodium chloride. Among other rigid porous mediums available are Kel-F sheeting (QD), polyvinyl chloride sheeting @ID),and a high porosity calcined refractory element (5D). Jordan (180) gave a qualitative exposition of the applications of porous ceramic filters. Streatfield ( 2 3 0 ) described filter-bed anthracite
INDUSTRIAL AND ENGINEERING CHEMISTRY
104
now being produced in Wales and related its successful use to replace sand in some water filters. One comprehensive (I7D) and one brief (2D) review of the origin, properties, and uses of diatomaceous earth filter aids were published. A filter aid derived from coal is now on the market in four grades. The claimed advantages are chemical inertness, combustibility, color, and economy (7D). Table I lists several patents on filter mediums or cartridges.
LABORATORY APPARATUS AND METHODS Apparatus described includes a simple immersion filter (I2E) and a manifold assembly of six filter funnels (I7E). A British Standard specification on filter funnels wa8 issued (2E). A twolayer combination of cotton wool and cellulose powder was recommended for microfiltrations (ISE),and a circle of commercially available glass paper was suggested as a Gooch mat (I6E). Cook and Hughes (8E) found filter paper to be a source of error in the phosphatase test for pasteurized milk. David (9E)used a pipe cleaner as a water filter. Diatomaceous earth will filter 2-micron particles from olive oil used in a sedimentation test ( I E ) , and asbestos fiber is useful in filtering Kauri-butanol solution (6E). Short directions have been given for the filtration of calcium borogluconate (16E) and the detanniaed solutions of tannin analysis (ISE). hlembrane filters and their use in bacteriological analysis were discussed in a number of papers (4E,IOE,I I E , IJE, 19E,20E). Clark (6E) and coworlters critically compared American and European hydrosol membranes, and found them somewhat different but both satisfactory. Coleman (78) and Bugher (SE)described ultrafiltration apparatus and membranes.
LITERATURE CITED REVIEWS, THEORY, AND EXPERIMENTAL STUDIES
Baron, T., and Oppenheim, A. K., IND.ENG.CHEM.,45, 941-
51 (1953). Chem. Age ( L o n d o n ) ,69, 417-40 (1953). Gardy, M., “La Filtration,” Paris, Presses ilocumentairies,
1952. Gothel, H., and Meissner, H., Chem.-Ing.-Tech., 24, 7034 (1952). Grace, H. P., Chem. Eng. Progr., 49, 303-18 (1953). Ibid, pp. 367-77. Ibid.,pp. 427-36. Halff, A. H., Sewage and I n d . Wastes, 24, 962-84 (1952). Haruni, M. bl.,and Storrow, J. A., Chem. Eng. Sei., 1, 164-64 (1952). Haruni, M. II.,and Storrow, J. A., IND.ENG.CHEM.,44, 2751-6, 275G63, 2764-7 (1952). Heertjes, P. M., Chem. Weekblad, 48, 573-8 (1952). Heide, R., von der, Chem.-Ztg., 77, 145-8, 1814, 208-11 (1953). Heinrich, K., Zucker, 5,465-73 (1952). Ingmanson, W. L., T e p p i , 35, 43948 (1952). Lauer, B. E., and Heckman, R. F., “Chemical Engineering Techniques,” New York, Reinhold Pub. Corp., 1952. M f g . Chemist, 24, 3 9 1 4 (1953). Orlicek, A. F., and Schmidt, A., Chem.-Ing.-Tech., 24, 457-8 (1952). Riegel, E. R., “Chemical Process Alachinery,” 2nd ed., New York, Reinhold Pub. Corp., 1952. Rietema, K., Chem. Eng. Sci., 2, 88-94 (1953). Rietema, K., thesis, Delft Technical School, Dec. 10, 1952. Shekhtman, Y.M., Izvest. A k a d . N a u k S.S.S.R., Otdel. Tekh. N a u k , 1951, 83943. Streatfield, E. L., Chem. &. Process Eng., 34, No. 2, 44-7 (1953). Tiller, F . M.,C b m . Eng. Progr., 49, 467-79 (1953). Waeser, B., Chem.-Ztg., 76, 507-10 (1952). Waeser, B., Deut. Furben-Z., 6, 393-8 (1952). Wrist, P. E., Research, 5, 475-81 (1952). EQUIPMENT
(1B) Aktiebolaget Separator, Brit. Patent 670,260 (April 16, 1952). (2B) Berkeley, W. H., J . Am. Water W o r k s Assoc., 44, 491-7 (1952). (3B) Chem. Eng., 60, No. 3, 242 (1953).
(4B) (5B) (6B) (7Bj (8B) (9B) (10B) (11B) (12B) (13B) (14B) (15B) (16B) (17B) (18B) (19B) (20B) (21B)
Vol. 46, No. 1
Ibid., No. 4,243. Ibid., No. 7, 208.
Ibid.. 24.5 , No. . 10. ~ ._ . ~. Forster, H. W., Sugar J., 15, KO.9, 25-9 (1953). Gilbert, W. G., J . New Engl. Water Works Assoc., 66, 263-13 (1952). Intern. Sugar J., 54, 282 (1952). Khomenko, A. A., Sakharnaya Prom., 26, No. 12, 24-8 (1952). Kilby, M. M., Repts. Assoc. Hawaiian Sugar Technol., 10th Meeting, 1951, 89-91; Intern. Sugar J., 55, 16 (1953). Paper Mill News, 75, KO.37, 26 (1952). Pollman, K. P., Caila y A t u c a r , 1, No. 2, 15-16 (1952): Intern. Sugar J . , 54, 299-300 (1952); Sugar, 47, No. 9, 37-8 (1952). Riddick, T. Rl.,J . Am. Wafe?Works Assoc., 44, 73344 (1952). Roe, F. C., Public Works, 83, S o . 9, 6 2 4 , 115 (1952). Schwob, Y., Chimie & industrie, 69, 64G-8(1953). Stauffer, K., Chem.-lng.-Tech., 25, 72 (1953). Tong, R. Jl.,Sci. Lubrication ( L o n d o n ) ,4, No. 10, 18, 19, 22, 33 (1952). Ulrich, E. A., Chem. Eng. Progr., 49, 561-5 (1953). Wi:inhold, K., Chem.-Iny.-Tech., 25, 349-50 (1953). Wilke, H., Chem.-Ztg., 77, 211-13 (1953). ~
PROCESS APPLICATIONS
(IC) BaokIund, P. S., and Jenkins, V. X., U. S. Patent 2,625,502
(Jan. 13, 1953). (2C) Black, R. F., Intern. Sugar J . , 55, 71-2 (1953). (3C) Braune, J. F., Gesundh.-Ing., 74, 12-15 (1953). (4C) Bruins, R. W., Dedell, T. R., and Hulse, S., 111, E. S. Patent Application 770,212; Of. Gas., U . S. Patent Ofice, 662, 292 (1952). (5C) Chodkiewicz, S. A., J . A p p l . Chem., 2 , 63941 (1952). (6C) Colegate, G. T., Electroplating, 5, 327-31 (1952). (7C) Ibid., pp. 367-71, 373-4. (8C) Ibid., pp. 401-7. (9C) Ibid., 6, 11-13, 51-3, 55-7 (1953). (lOC) Ibid., pp. 85, 87-9, 91, 93-4. ( l l c ) Consoer, 8. w., J . A m . Water Works L4SS0C.,45, 737 (1953). (12C) D’Aquin, E. L., Vix, H. L. E., Spadaro, J. J., Graci, A. V., Jr., Eaves, P. H., Reuther, C. G., Jr., Molaison, L. J., McCourtney, E. J., Crovetto, A. J., Gastrock, E. A., and ENG.CHEM.,45, 247-54 (1953). Knoepfler, 3’.B., IND. (13C) Dean, H., Am. City, 68, No. 3, 8&7, 169, 171 (1953). (14C) Durham University, Xewcastle-upon-Tyne, England, King’s College M i n i n g E n g . Bull. 6, No. 2 Series: Coal Cleaning, No. 10. (15’2) Eden, G. E., Downing, A. L., and Wheatland, A. B., J . Inst. Water Engrs., 6, 511-32 (1952). (16‘2) Eichenlauer, H., and Symons, G. E., Public Works, 83, KO.7, 54-6, 70 (1952). (17C) Engelhardt, W. von, and Schindewolf,E., Kolloid-Z., 127, 15064 (1952). (18C) Engler, Gas- u. Wasserfach, 94, 201-5 (1953). (19C) Fessler, J. H., U.S.Patent 2,596,392 (May 13, 1952). (20C) Finney, J. W., Public Works, 83, No. 11, 60-1, 9 6 7 (1952). (21C) Gastrock, E. A., D’Aquin, E. L., and Vix, H. L. E., Cotton G i n & Oil Mill Press, 53, 31-7 (May 1952). (22C) Geiss, W., “Die Filtration von Wein Siismost, Seshaumwein und Spirituosen,” Joh. Wogner & Sohn, Frankfurt-amMain, 1952. (23C) GBnin, G., Peintures, pigments, uernis, 28, 386-95 (1952). (24C) Graci, A. V., Jr., Reuther, C. G., Jr., Eaves, P. H., Rlolaison, L, J., and Spadaro, J. J., J . Am. Oil Chemists’ Soc., 30, 13943 (1953). (25C) Gregory, D. H., and Whelan, P. F., Trans. Inst. Mining Engrs. (London), 112, 767-8 (1953). (26C) Hauptmann, K. H., Inds. agr. et aliment ( P a r i s ) , 69, 577-80 (1952). (27C) Hazen, R., J. Am. Water Works Assoc., 45, 723-34 (1963). (28C) Honig, P., “Principles of Sugar Technology,” Houston, Elsevier Pub. Co., 1953. (29C) Hubel, J. E., Water Works Eng., 105, 133 (1952). (30C) Jenninger, E., Gas- u. Wasserfuch, 93, 648-9 (1952). (31‘2) Jensen, N. H., Iron Steel Engr., 30, No. 3, 70-5 (1953). (32C) Jepson, C., and Greene, G., Inst. Sewage P u r i f , , J . and Proc.. 1951,26-35. (33C) Jepson, C., and Klein, L., Ibid., 1951, 36-45. (34C) Kalinske, A. A., J. Am. Water F o r k s Assoc., 45, 734-7 (1953). (35C) Uralekas, P., Am. City, 67, No. 9, 99-100 (1952). (36C) Keefer, C. E., and Meisel, J., Water & Sewuge W o r k s , 100,80-4 (1953). (37C) Knoedler, E. L., Ibid., 99, 180-3 (1952). (38C) Kortschak, H. P., Hawaiian Planters‘ Record, 54, No. 2, 65-75 (1952); Intern. Sugar J.,55, 163 (1953). (39C) Lumb, C., I n s t . Sewage Purif., J . and Proc., 1951,5-15.
1
January 1954 (40C) (41C) (42C) (43C) (44‘2) (45C) (46C) (47C) (48C) (49C) (50C) (51C) (52C) (53C) (54C) (55C) (56C) (57C) (58C) (59C) (60C) (61’2) (62C) (63C)
INDUSTRIAL AND ENGINEERING CHEMISTRY
Madon, P., I n d s . agr. et aliment ( P a r i s ) , 69, 193-200 (1952). Marsh, J. A., Taste Odor Control J., 19, No. 4, 1-8 (1953). Meade, G. P., Intern. Sugar J., 55, 68, 70 (1953). Modjeska, R. S.,and Faint, H. W., Proc. Am. Electroplaters’ SOC.,39, 69-75 (1952). Monson, R. E., Am. C i t y , 68, No. 4, 86-8 (1953). Moore, T. I., and Painter, L. A., J . Metals, 4, Trans. 1149-59 (1952). Nesvadba, L., M i t t . chem. Forsch.-Inst. Wirtsch. &err., 6, 45-9, 67-70 (1952). lieufield, J. C., M u n i c . Utilities, 90, No. 10, 22-3,43, 44, 46, 48 (1952). Newell, J. F., and Christenson, C. W., E n g . News-Record, 147, KO. 19, 37-8 (1951). Nicolaysen, V. B., and Borgin, G. L., Norsk. Skogind., 6, 33841 (1952). Oliver, G. C. S., J . I n s t . Water Engrs., 6, 196210 (1952). Pettet, A. E. J., Collett, W.F., and Waddington, J. I., Inst. Sewage P u r i f . , J . and Proc., 1951, 195-202; Sewage and I n d . W a s t e s , 24, 825-43 (1952). Pinkerton, K. E., Am. Soc. Brewing Chemists Proc., 1952, 106-8. Piros, R. J., Brusenback, R. A., and Dahlstrom, D. A , , T r a n s . Am. I n s t . Mining M e t . Engrs., 193, Tech. Pub. No. 3422-F; M i n i n g Eng., 4, 1236-43 (1952). Poggi-Lollini, A., Pitture e vernici, 8 , 311-16 (1952). Powell, S. T., Power, 96, No. 8 , 74-7, 204, 206 (1952). Quentin, G., Zucker, 6, 303-8 (1953). Rybicki, Z.,Przemysl Chem., 30, 716-22 (1951). Saha, J. XI., Chandra, G., and Jain, K. S.,Proc. 80th Cone. Sugar Tech. Assoc. I n d i a , 1951, Part 11, pp. 59-64; Intern. Sugar J . , 55, 247 (1953). Stewart, C. W., Sugar J . , 14, No. 10, 12-14 (1952). Wallerstein, L., Saleman, L. T., and Gray, P. P., ISD. ENG. CHEM.,44, 2768-76 (1952). Wheeler, R. T., C a l i f , Oil W o r l d , 45, No. 13, 4, 6, 8, 10, 12, (1952). Wigund, J., Zucker, 6, 298-303 (1953). Yu, C. T., Chang, T. H., and Wang, P. C., Sugar, 48, KO,5, 62-64 (1953).
FILTER M E D I U M S AND FILTER A I D S
(1D) C a n . Chem. Processing, 36, No. 13, 50, 52 (1952). (2D) I h i d . , 37, No. 5, 76, 78, 80 (1953). (3D) Ibid., No. 9, 22, 56, 58-9. (4D) Chem. Eng., 60, No. 3, 205 (1953). (5D) Ibid., No. 5, 244. (6D) Ibid., S o . 8 , 230. (7D) Ihid., No. 9, 256.
105
(8D) Ibid., pp. 256, 258. (9D) Ibid., S o . 10, 244. (10D) Ibid., p. 245. (11D) B r i t . R a y o n & Silk J . , 29, S o . 342,44-8, 50, 52 (1952). (12D) Engineers’ Digest, 14, 198 (1953). (13D) Everhart, J. L., Materials & Methods, 37, No. 4, 98-100 (1953). (14D) Fibre Containers, 38, No. 1, 68-9 (1953). (15D) Grove, C. S., Jr., Vodonik, J. L., and Casey, R. S., IND.ENG. CHEM.,45, 2199-205 (1953). (16D) Heath, F. R. C., T r a n s . B r i t . Ceram. SOC.,52, 153-73 (1953). (17D) Hull, W. Q., Keel, H., Kenney, J., Jr., and Gamson, B. W., IND.ENG.CHEW,45, 256-69 (1953). (l8D) Jordan, G. V., Jr., Mech. Eng., 75, 559-63, 566 (1953). (19D) Kane, E., Chem. Eng. Progr., 49, 487-90 (1953); IND.ENG. CHEM.,45, 8 6 0 4 (1953). (20D) Kniep, E., Sprechsaaz, 85, 371-3 (1952). (21D) Mfg.Chemist, 24, 140 (1953). 122D) Pall, D. B., IND. ENG.CHEM.,45, 1197-1202 (1953). (23D) Streatfield, E. L., Engineer, 193, 7 7 1 4 (1952). (24D) Van Norden, 0. H., U. S.Patent 2,631,110 (March 10, 1953). L A B O R A T O R Y A P P A R A T U S AND M E T H O D S
(IE) Benfield, D. A., and Young, R. S., Chemist A n a l y s t , 41, 94-5
(1952).
(2E) (3E) (4E) (5E) (BE) (7E) (8E) (9E) (10E) jllE) (12E) (13E) (14E) (l5E) (16E) (17E) (18E) (19E) (20E)
B r i t . Standards, No. 1923 (1953). Bugher, J. C., J . Gen. Physiol., 36, 43148 (1953). Bush, J. H., Water & Sewage W o r k s , 100, 151-3 (1953)
Clark, H. F., Jeter, H. L., Geldreich, E. E., and Kabler, P. W., J . Am. Water W o r k s Assoc., 44, 1052-6 (1952). Colcher, H. J., Chemist A n a l y s t , 41, 67 (1952). Coleman, I. W., C a n . J . M e d . Sei., 30, 246-9 (1952). Cook, G. T., and Hughes, K. E. A., D a i r y I n d s . , 18, 43-5 (1953). David, N. A., Chemist A n a l y s t , 42, 47 (1953). Goets, A., J . Am. W a t e r W o r k s Assoc., 45, 933-44 (1953). Goets, A,, Gilman, R. H., and Rawn, A. M., J . Am. Water W o r k s Assoc., 44, 471-83 (1952). Hahn, F. L., A n a l . C h i m . A c t a , 7, 438-40 (1952). Kainz, G., Mikrochim. A c t a , 1953, 119-23. Kruse, H., Gas- u. Wasserfach, 93, 712-15 (1952). Ma, T. S., and Benedetti-Pichler, A. A., A n a l . Chem., 25, 999-1000 (1953). M f g . Chemist, 24, 121 (1953). Marshall, C. V., Chemist A n a l y s t , 41, 68 (1952). Martin, H., and Grosjean, E., B u l l . assoc. f r a n c . chim. inds. cuir et doc. sei. et tech. i n d s . cuir, 14, 15-18 (1952). Petrovich, S.L., Gigiena i Sunit., 1952, No. 6, 19-22. Potkov, L. A., Mikrobiolgiya, 20, 343-7 (1951).
FLOTATION This review follows closely in outline that of Clemmer (20) and covers publications in the period of about a year prior to October 1953. Research in the field of flotation has been active ture stressed the application of such work in elucidating the behavior of collectors and depressants on mineral surfaces, in control of nonradioactive plant processes, and as a possible tool for mineral sorting (19). Other papers included in the volume cover the influence of crystal latices, surface chemistry of flotation, chemistry of frothing agents, bubble-mineral attachment, applications of radioactive isotopes and electrochemical methods t o flotation research, selective flotation of minerals, flotation of oxidized lead and zinc minerals, and current practice at several plants. A number of reports were published b y investigators of the U. S. Bureau of Mines on the treatment of ores of various types including Virginia lead ( l 7 ) , Idaho antimony (37), Maine and Minnesota manganese (62,63), and Nevada oxidized copper (28) ores.
and the publications on this work and its applications have been numerous.
papers on the beneficiation of sulfide and oxide ores appeared, and an extended interest was ’ evident in some of the newer extentions of the flotation method for the treatment of nonmetallics, oxidized ores, and coal. An extensive series of papers relating to froth flotation was presented at the symposium on mineral dressing held in London in September 1952 under the auspices of the Institution of Mining and Metallurgy. These papers form part of a recently published volume covering various phases of mineral dressing (44). This volume contains the inaugural lecture-the Sir Julius Werner Memorial Lecture-delivered b y A. M. Gaudin, who summarized the studies of several investigators with radiotracers. The lec-
