VISCOSITY OF LIQUID-LIQUID DISPERSIONS IN LAMINAR AND TURBULENT FLOW John Anthony Cengel A THESIS subRitted to OREGON STATE COLLEGE in partial fulfillment of the requireiients for the degree of Master of Science June, 1960 APPROVED: Redacted for Privacy Prjessor of Chemical Engineering In charge of Major Redacted for Privacy d of Department of Chaical Engineering Redacted for Privacy Chairman of School Graduate Conunittee Redacted for Privacy Dean of Graduate School Date thesis is presented 3pemep' 9//f Typed by Claire Waisted ACKNOWLE DGMENTS The writer is priviledged to make the following acknowledgments: To the National Science Foundation for finan cial support in the form of a research grant. To Dr. James G. Knudsen, the writer's major pro- fessor, for suggesting the overall problem, for his guidance and aid, arid for his inspiring confidence when it was most needed. To Mr. Charles Wright, graduate student in the Chnical Engineering Department, for his invaluable assistance in obtaining data. To Mr. Arne Landsberg, graduate student in the Chemical Engineering Department, for his construction of the emulsion evaluator, and for his helpful hin about its operation. Finally, to the One, because of whom this thesis was completed, and to whom it is fondly dedicated. ( I t. EOI1; 4ICiL &;iJJ.3IO * F1.ica i;ewtQr.i uepc2-$: c1tJ I flay ¶artic1e 3e trtozt cf jç : , u Pipiri : yaCt 2e YJL.t(v 4 EI:iL i:5 ioi irL;lr& :'c1 iccesit Capil1ar ..uc V .;coatr P1ctpolerc lMcrt ChtCJ Capi11r; 1C CftIirtic iar Flay Vj;colty v'11 fzitrar F10 icitio :1crt Zlcw Vjscoiy 1icn Vu 2 r) .. e. t.s otc1etic i "' '-' q'l ,. ' ,, ,.,-. - C 4. CiLIki1IO! _I_ -4- I.3 LIST OF FIGURES Fi9ures Page 1 VISCOUS CHARACTERISTICS OF FLUIDS 8 2 EFFECT 0? FLOW RATE ON VISCOSITY 8 3 VISCOSITY AS A rtJNCTION OF CONCENTRATION 11 4 VISCOSITY AS A FUNCTION OF SHEAR RATE 11 5 SHEAR STRESS AT WALL OF CAPILLARY VERSUS RECIPROCAL SECONDS 19 6 SCHEMATIC FLOW DIAGRAI\i 23 7 DIAGRAM OF TESril SECEIONS 24 8 SUPPLY AI4. MD PUP 26 9 MANOMETER BOARD ARRANGEMENT 29 10 LIGHT AND PHOTOCELL PROBES 33 U WIRING DIAGRAM FOR PHOTOELECTRIC EMUIION EVALUATOR 36 12 PLOT TO DETERMINE FLOW RATE 51 13 PLOT OF 1/ 14 LAMiNAR FLOW VISCOSITIES OF WATER, 5%, 20%, AND 35% DISPERSIONS 56 LAMINAR FLOW VISCOSITIES OF SOLVENT AND 50% DISPERSION 57 15 16 F VERSUS wfr 53 EFFECT OF REYNOLDS ii3MEER IN PIPING SYS TEM ON MEASURED LAMINAR VISCOSITY WITH 17 18 19 CONSTANT iP ACROSS CAPILLARY TIlDE 58 SHEAR STRESS AT CAPILLARY WALL VERSUS RECIPROCAL SECONDS 64 TURBULENT FLOW VISCOSITIES AS A FUNCTION OF FLOW RATE 66 PLOT OF VARIOUS DISPERSION EATIONS 70 L OFFI tJRES (continued) Figure 20 Paqe AMOUNT OF LIGHT TRANSMITTED AS A FUNC TION OF MIXIiC 21 I1E EFFECT OF FLOW iATE ON AMOUT OF LIGHT TRANSMITTED 22 23 24 71 73 DENSITY OF WATER AND SOLVENT VERSUS :1Trtn7,.)I rir'i 39 VISCOSITY OF SOLVENT A. D WATER VERSUS TEMPERA2URE 90 PRESSURE GAGE CALILRAflON CURVE 92 LIST OF TAB LFS Table Pacte 1 CAPILLARY TtJEE DIMENSIONS 30 2 NOMINAL AND MEASURED COMPOSITION 40 3 CAPILLARY TUBE INFORMATION 54 4 MANUFACTURER'S SPECIFICATIONS 8? 5 TURBINE PUMP CHARACTERISTICS 91 VISCOSITY OF LIQUID-LIQUID DISPERSIONS IN LAMINAR AND TURBULENT FLOW CHAPTER 1 INTROJECTION Two-phase systems have been known since the beginning f chemical history. However, the behavior of such systems in flow has beer under investigation for only a relatively short portion of that time. This behavior has become in- creasingly important to the modern chemical engineer in all inthstries. With the development of liquid-liquid extrac- tion apparatus, fluidized catalytic chnical reactors, and other processing equipment, knowledge of the physical prop- erties of two-phase systems is a prime factor. Considerable study has been given to gas-liquid, gas- solid, and liquid-solid dispersions. In addition there been investigation of combinations of these systems, as liquid-liquid-solid dispersions. has such Yet relatively little has been accomplished in the region of liquid-liquid flow. The determination of the physical properties of liquid- liquid dispersions is one of the most necessary contribu- tions that can be made to chemical engineering theory. The viscosity of such dispersions is probably the most unique and important of those properties. standpoint, the From the commercial viscosity is important, since it plays a 2 major rcie in the design of equipment and since many dispersions may be marketable only at specific viscosities. nowledge of viscosity has a theoretical value also. The viscosity, together with hydrodynamic theory, can give considerable information about the structure of dispersions and clues to their stability. It was therefore decided to undertake the task of meas uring the viscosity of a dispersion of immiscible liquids. Apparatus was designed and built to permit measurement of both the laminar and turbulent flow viscosities of a petroleum solvent in water. Of secondary interest was the investigation of the amount of light transmitted through water as a function of the interfacial area. This thesis presents the results of this investigation. CHAPTER 2 THEORETICAL DISCUSSION The physical properties of fluids are in constant use in chemical engineering calculations, Probably the most important of them is the viscosity, or more properly, the coefficient of viscosity. This is the quantitative meas- ure of the tendency of a fluid to resist shear. As a fluid flows, it is deformed by applied external frictional effects forces bringing about exhibited by the motion of molecules relative to each other. These effects are encountered in all real fluids. The classic example is two parallel plates, analogous to layers in a fluid, a differential arated by a fluid. Shear stress distance dy apart sep- must be exerted to keep at a constant relaThis force is directly one plate moving parallel to the other tive velocity to the other plate. proportional to the velocity gradient dy/dy. tionality factor is removed by introducing The propor- the coefficient of viscosity,p (1) 7 TF =pdv dy The coefficient of viscosity is a characteristic physical property of all real fluids. Its numerical value for any particular fluid is dependent upon the temperature, pressure, and velocity gradient or rate of shear. 4 The unit of viscosity in the c.g.s. system is the poise, 1(dyne) (sec) /sq cm = 1 g/ (sec) (cm), and in the English system, lb/ (ft) (sec). The viscous force may also be expressed as a rate of momentum transfer between the fluid layers. The shear stress is a force per unit area and is equivalent to a rate of change of momentum. Numerous methods have been devised to determine the viscosity of fluids. Basically all methods make use of Equation (1), in which a known shear stress is applied to the fluid and the resultant rate of shear determined. From the two quantities the viscosity may be calculated. One common method makes use of the capillary tube viscometer, in which the pressure drop occuring during lainflow through a capillary tube may be used to calculate case, i.e. /u= 7Tr4PO (2) 8LV where L radius of capillary tube pressure drop across tube length of tube V volume of measured efflux from tube ê time to collect ef flux r ti P This method of measurement was chosen for the pre ent work because of the convenience involved in obtaining a suitable sample for study. As pointed out in a subsequent section, a class of fluids known as non-Newtonian exhibit behavior in which the viscosity is a function of shear stress. Consequert ly such fluids oftentimes exhibit different viscosities in laminar from those in turbulent flow. The turbulent flow viscosity is the viscosity which satisfies the following equations applied to turbulent flow in a smooth pipe. LPf 3) D and 2pU2 4.0 log (Re (4) f i P P )° U Re if ) Fanning friction factor pressure drop due to friction, = Diameter, density, -0114 /1 2 ft ibm/ft3 velocity ,ft/sec = conversion constant 32.17 (ibm) (ft)/lbf (sec) Reynolds number Newtonian Fluid A Newtonian fluid is one in which the viscosity is independent of the rate of shear, i.e. is constant in equation (1) at constant pressure and temperature. The viscosity of all Newtonian liquids decreases with an increase in temperature, at constant pressure. The vis- cosity of gases increases as the temperature increases, at constant pressure. This behavior is in accordance with the kinetic theory of gases. For most liquids the viscosity increases with pressure at a constant temperature. The viscosity of gases also increases with pressure, contrary to the kinetic theory, whIch states that the viscosity of a gas should be independent of pressure. The viscosity of the liquid and that of the gas beco-e ident3.cal at the critical point. Non.-Newtonian Fluids A non-Newtonian fluid is one in which the viscosity is also a function of the rate of shear, in general, nonNewtonian fluids may be classified by three groups--plastic, peeudoplastic, and dilatant. Referring to Figure 1, it may be seen that, for a true Newtonian fluid, the shear stress is directly proportional to the rate of shear (curve I). The plastic fluid (curve III) is one which requires a 7 definite stress known as the yield point to start the material flowing. An ideal plastic flows as a viscous material according to curve lila. Moat plastics exhibit a bend in the line at x because of a breakdown at the interlocking arrangenent of the molecules. The pseudoplastic fluid (curve II) exhibits a continuous decrease of viscosity, with an increase in shear rate, approaching a Newtonian behavior at high shear rates. The dilatant fluid (curve IV) is one whose apparent viscosity increases continuously with increasing rate of shear. Figure 2 8howE how the character of the viscosity affected by shear rate. It appears that all fluids would behave as Newtonian fluids at high rates of shear. )ns The viscosity of a suspension at very low concentraone of the dispersed phases in general are Newtonian in ture. However, as the concentration of the dispersed phase increases, the fluid tends to become non-Newtonian. Workers in the field of rheology have been classifying the non-Newtonian suspensions by the old standards applicable to a single phase flow, i.e, plastic, pseudoplastic, or dilatant. Yet it has been repeatedly shown that the classification into which a suspension falls and 8 SHEAR STRESS FIGURE 1. VISCOUS CHARACTERISTICS OF FLUIDS DILATANT NE42ONIAN PS DUD OFL AS TIC RATE OF SIAR (±LOW) FIGURE 2 EFFECT OF FLOW RATE ON VISCOSITY 9 even the numerical values assigned to its rheological properties is extremely dependent upon the experimental condi- tions under which the measurements were made. ?or instance, a particular suspension under different rates of shear can exhibit plastic, pseudoplastic, and even Newtonian characterietics at a constant temperature and pressure (37, pp. 4344O), Therefore, the viscosity of suspensions is re- f erred to as an apparent viscosity. A vast amount of literature exists supporting the conclusion that the determination of the viscosity of suspensions is a very complex problem. Most of the literature deals with gas-liquid, gas-solid, and liquid-solid suspensions or dispersions. tereet in liquid-liquid eering1 Although there is a great deal of indispersions in modern chemical engin- there has been little accomplished in that direction. The following discussion concerns suspensions at contemperature. The viscosity of suspensions depends upon several fac- 3, p. 2S3); ) The volume concentration of the dispersed phase The rate of shear The viscosity of the continuous phase The viscosity of the dispersed phase The size and shape of the dispersed partic 10 The distribution of the particle The intorfacial tensions exhibited by the particles. In general, as the concentration of the dispersed phase increases, the apparent viscosity increases (Figu up to maximum value, where inversion takes place. The point of inversion is very difficult to measure because the instability of the suspension at that point (22, p. 512; 16, p. 1). The majority of the suspensions also exhibit flow, with the visdeclining as the rate of shear increases a pseudoplastic behavior in turbulent cosity steadily until a limiting viscosity,,, is approached (Figure 4) (48, p. 417; 8, p. 84). However, it is not uncotinton for a particular suspension to show several non-Newtonian characteristics. Alves (42, p, 108) states that in general non-Newtonian suspensions behave as Newtonian fluids in the turbulent flow region. This statient has not been substantiated by other workers and presumably refers to the limiting region of/b.. Lewis, Squires, and Thompson (29, p. 40) emphasize that the viscosity of a suspension is independent of particle size as long as particles are all the same size. If the particles are polydispersed, i.e. many-sized, another variable is introduced. Several solutions were given to explain the observed pstdop1astic behavior. Wilkinson (60, p. 595-600; &: p. 11 aS I 0 I VCLTJ1E FRACTION DISPERSED PHASE, FIGTJJ 3 VISCOSITY AS A FUNCTION OF CONCENTRATION RATE OF SHEAR FIGURE VISCOSIIY AS A FUNCTION OF SHEAR RATE 12 7984) and Robinson (47, p. 549) theorize that the molecules or particles are progressively aligned or oriented in the direction of flow. The viscosity will continue to decrease until no more alignment is possible. Hence the limiting viscosity. Another suggested theory is that the existence of a ufficient1y thick layer of liquid around discrete particles would account for the viscosity rising with decreased shear rate (35, p. 574). This explanation is mainly applicable to solids suspended in flowing fluids. Einstein (11, p. 300 and 12, p. 592) was the first to consider the problem of two phases. His mathematical treatment led to the famous wEinsteinN equation (5) m Pc (1 + k) where in 0 k is the apparent viscosity of the dispersion, is the viscosity of the continuous phase, is the volume fraction of the dispersed phase, is the "Einstein constant" 2.5, Einstein assumed a dispersion of uniform rigid spheres ins liquid. The spheres were separated by distances much larger than the partical diameter, random in orientation, concentration. The equation is actually a limiting law and not considered non-agglomerating in tendency, and low in applicable for volume fractions greater than 0.02 for the dispersed phase (2, p. 59). The value of 2.5 for the "Emstein constant" is very much in dispute. Huggins (21, p. 911) says that there is no valid reason to use 2.5, mainly because there is considerable difficulty in measuring properties of suspensions at low concentrations. Ting and lAlebbers (55, p. 116) claim that, for systems of many-sized particles, voids filled and formed by polydispersed particle5 account for the discrepancy of Einstein's constant. }iatschek (19, p. 80) derived an equation similar in form to equation (2), but called "Einstein's constant" 4.5. Many workers, in an attempt to correlate data, later expanded Einstein's original equation in the form of a polynomial, /ra 1c (1 + k +a 2 + b3 +, where k is "Einstein's constant," and a and b are constants for a particular suspension. A survey of the literature showed that there was no defined, accepted value for k. Several experimenters reported values from 1.5 to 18--Orr & Blocker (42, p. 24), Ward & Whitmore (59, p. 286), Hatschek (20, p. 80), Kunitz (25, p. 716), Donnet (7, p. 563), Oliver & Ward (40, p. 397) Thiclauxe & Sachs (9, p. 511), Eveson, W1-dtinore & Ward (15, p. 105), Eisenschite (14, p. 78) and Eirich, Bunzl & Margaretha (13, p. 276). Others report more extreme values 14 such as 35, Sachs (50, p. 280), and 150, 245, and 340, Roller & Stoddard (48, p. 419-20). The equations that sega most representative of the preceding group are Kunitz's (25, p. 716) /1 =JJ (1 and Happel's (1, p. in + 4.50+ l2çb 2 + 25 1298) c where is an interaction constant ranging from 1.000 to 4.071, while varies from 0.0 to 0.5. Other experimenters, attetpting to fit their data the polynomial equation and still keep "Einstein's con- stant" of 2.5, were Eirich, Bunzi, and Margaretha (13, p. 276), Eilers (10, p. 154), Manley and Mason (3, p. 764), Cling and Schachnan (5, p 24) and Vand (57, P. 298). An example is Vand's equation I/Im (1 + 2.50+ 73492 + The values of the "a" constant in the polynomial equa- tion (6) were in the range from 7.17 to 14.1, while the "b" constant were in the range from 8.78 to 40. All of the preceding equations were derived without taking the viscosity of the dispersed phase into account. Taylor (54, p. 418) modified Einstein's equation clude the viscosity of the dispersed phase to in- 15 ILJ&* (10) where d is the viscosity of the dispersed phase. Equation (10) was reported to be applicable for liquid- liquid systems. Leviton and Leighton (28, p. 71) obtained an empiri- cal equation from data on oil-in-water emulsions. + (11) 0.4,L/ ( çb1113 id+c J Vermeulen, Williams ) and Langlois (58, p. 81) present an equation for liquid-liquid dispersions (12) Some workers, deciding that there was no valid rea- son to assume that the Einstein equation was applicable at higher concentrations of the dispersed phase, developed more equations desiqred to treat the complexities of two-phase flow. Hatschek (20, p. 1o4) presented an empirical equation which successfully predicted the viscosities of red blood corpuscles. 16 1 i-ç= (13) Equation (13) was later modified by Sibree (53, p. 35) to include a volume factor "i" multiplied. by the volume fraction in the denominator. The equation was successful for stabilized paraffin-water iu1sions. npirical relationships (49, p. Roscoe developed two 268 [i4] 2.5) which describes the characteristic viscosity of a suap sion of marty-sized particles, and /1 ( = [1_1.35c] _2.5) which is applicable to suspensions cf uniform spheres. Richardson (45, p. 32) discusses an equation applicable to oi1-in.water enulsions. IUmIic (Ca) where "a" is a constant depending upon the system. Eilers (10, p. 313) presents an epirica1 equation applicable to his work on asphalt suspensions. (17) Ii L + L.25 1(ç/o.78) -2 Miller and Mann (38, p. 719) and Olney and Carison (41, p. 475) developed a logarithmic expression for immiscible liquids ,L/=,L/ ,LI Finally Finnigan (17) reports a correlation for petroleum advent in water. .,L (1+2.5 +4.602 Si Measurement of V When measuring the viscosity of a suspension by means of a capillary tube, workers have found that the apparent viscosity depended not only upon the shear rate but also upon the diameter of the capillary tube. It appears that the measured viscosity will increase with increasing diameter (15, p. 1074; 33, p. 981). This effect, known as the sigma effect, has been explained by Vand (57, p. 277), who assumed that slip takes place between the wall and suspen- sion, the suspension acting as though there were a layer of pure fluid adjacent to the wall, De Bruijn (6, p. 220) atates that the sigma effect is caused by the interaction of the particles subjected to shear. Sherman (51, p. 571) shows that the viscosity is a. function of the shear rate in a particular tube. Lindgren 18 p. 135-6) showed that, with 1.02% bentonite solution 1]. as with the flow of distilled water, the viscosity ed increased linearily with increasing shear rate fr a Reynolds number below 500 to one near 3000. In his riinents Reynolds himself noted this irregularity (44, p. 84). Merrill (36, p. 462-5) states that the capillary tube produces a shear rate varying continuously from zero at the center to some maximum value at the wall. of diameter the value of the With each change shear stress on the fluid at the capillary wall is altered, and thus moves up or down on the non-Newtonian shear stress-shear rate relations. Richardson (46, p. 367-73) states that the continuous shearing action over the comparatively long time of flow required to get a reading may result in a breakdown of some of the globules. A correlation (8, p. 144; 60, p. 600) has been developed which plots the shear stress at the wall versus volumetric flow rate terra (Figure 5). a Assuming that lam- inar flow exists, that there is no slip at the wall, and that the rate of shear at a point depends only on shearing stress at that point and is independent of time, all data should lie on one line. When one or more of the assump- tions fail, the figure shows that, by increasing the diameter at a constant length or by increasing the length at 19 k I FLOW RATE TJRN, SEC1 FIGURE 5. SHEAR STRESS AT WALL OF CAPILLARY VERSUS RECIPROCAL SECONDS 20 constant diameter, different values of shear stress at the wall are obtained for a particular flow term. Since vis- coity depends upon the shear stress, it is evident that the measured viscosities will depend on tube dimensions. Narayanaswamy and Watson (39, p. 75), while studying oil-inwater emulsions, found that entrainment of air was a factor in erratic measurements of viscosity. The a sumption was that the air formed very fine bubbles which lent themselves to a polydispersed system. Measurement of Particle Size Many attempts and have been made to determine the size interfacial area of dispersed particles. Most suc- cessful investigators have relied upon photographic techniques. Langloiso and Gullberg (27, p. 360) give a relationship using light transinittancy. BAl (20) 0 is the light incident to suspension, I is the light intensity emergent, A is the interfacial area per unit volume, is a specifying constant dependent on the ratio of refractive indices. and 21 The constant B was considered to be independent of the vol- ue fraction of the dispersed phase. This method may prove erroneous because in dilute solu- tions scattered light is lost, while in concentrated solutions secondary scattering recovers it. CHAPTER 3 EXPERIMENTAL EQUIPMENT The apparatus illustrated schematically in Figure 6 was designed to enable investigators to determine both heat transfer coefficIents and the laminar and turbulent viscos- ities of liquidliguid dispersions. the evaluation of the dispersion. This thesis concerns A treatment of the heat transfer experiments may be found in a thesis (62) presented at Oregon State College. Figure 7 shows the extent of the apparatus employed in the viscosity observations. A stainless steel tank with a jacket for water cooling was used both for containing the test liquids and f or mixing. A va.riale speed stirrer with propeller blades was used for agitation. The dispersion was pumped through the piping system the respective test sections, where measurements wore made of the viscosity and heat transfer coefficients. A by-pass at the pump was used to regulate flow and to provide additional mixing. The dispersion was returned to the supply tank through a secondary flow control valve. A flexIble hose was used at this point so that the flow could be diverted to a weigh tank for measurement of the flow. Additional equipment associated with the main piping system was an orifice meter, a static pressure gage, a THERMOCOUPLE WELL (j 2-INCH GATE VALVE r7ll- INCH GLOBE VALVE > WATER A; f-HC HEAT EXCHANGER (}1-INCn GATE VALVE A - ORIFICE WATER B - CAPILLARY TUBE C - TO MANOMETERS PRESSURE D - MIXING TANK GAGE TO E - BECKMAN SEWER FLEXIBLE HOSE THERMOMETER I'll' I....' STIRRER I, ulIuUUhuIIlI1I 4111111111111 liii 6-FOOT HEATING COIL C C E2'IULS ION EVALUATOR 03 PLATFORM SCALE T TAP TURBINE PUMP WATER FLUSH 0 DRAIN FIGURE 6 SCHEMATIC FLOW DIAGRAM 2 PRESSURE TAPS COPPER Tw3E PART A PRESSURE GAGE 21" CAP ILLARY ruBE NEEDLE VALVE 1" BRASS PIPE PLATFORM AND 38" WEIGH CUP TO D.C. BATTERY 11" 1- UNION I II THBMOCOUPLE WELL TO GALVANOMETER III EMULSION EVALUATOR 19" 1 PART B FIGURE 7. DIAGRAM OF TEST SECTIONS 25 photoelectric emulsion evaluator, a capillary viscoxaeter, a sight glass, a baffled mixing chamber, a heat exchanger, a sample tap, three temperature wolls, and appropriate piezometer taps and valving. There was also a 6-foot horizontal section wrapped with nichrome ribbon for heating. The scope of the following detailed description will cover only those parts of the apparatus which directly apply to the viscosity evaluaticn experiment. Supply Tank and Pum The supply tank and pump are the same as used by Finnigan (17) and are described in detail by him. Figure 8 shows a photograph of this portion of the experimental ap- paratus. Piping System The piping system was constructed of nominal 1*-inch brass pipe, nominal 2-inch brass pipe, 7/8-inch O.D., 16 BWG copper pipe, and a section of flexible synthetic rubbor hose. The 2-inch pipe was located between the supply tank and the pump. The copper line was located between the two vertical sections of the system, and the flexible hose s located, at the ef flux point of the system. All other piping was 1*-inch standard brass. A 2-inch gate valve (number 1, Figure 6) was installed 11 1-4 27 between the mixing tank and pump to aid in controlling flow and so that the piping system could be drained independently of the tank. A 1*-inch gate valve was placed between the pump and by-pass line and between the pump and main flow system. The by-pass valve (nu.iuber 2, Figure 6) was used to aid in controlling the amount of flow through the test sectIons. The main system valve (nuither 3, Figure 6 was used to isolate the main system from the supply tank and was kept wide open during all runs. With this valve closed, changes could proceed on the test sections without disturbing the mixing. Finally a 1*-inch globe valve (number 4, Figure 6) was installed at the ef flux point to regulate flow and to insure that the aain piping system renamed full when the apparatus was not in operation. AU threaded connections were made with the assistance of "Cyl-sea1 high pressure sealant manufactured by the West Chester Chemical Company and the seats of all unions were sealed with Perxnatex No. 2, manufactured by the Perinatex Company, Incorporated. It was found that these sealants were imperious to the liquids used In the experiment. Unions were used wherever possible for quick disassenbly and repair of the equipment. Provision was made at the low point of the system for drainage. Flow rates were determined by means of a brass, sharp-edged orifice 28 plate in the vertical section downstream from the pump. This was constructed by Finnigan (17) for previous experimental work on the same system of fluids. His calibration curve is shown in Figure 12. Flow rates determined with the orifice meter were within ±41 of measured flows. Test Section Figure 7 illustrates the test sections used to eva uate the laminar and turbulent viscosities,, Part A was used to determine the turbulent flow viscosities. This section was a 6-foot long, 7/8-inch O.D., 16 EWG copper tube, over which the pressure drop was measured. The piezometer openings were located at the zero and 6-foot distances by drilling l/2-inch diameter holes perpendicular to the pipe wall and brazing short *-inch brass nipples in place. The inside surface was cleaned with emery cloth to insure an opening free from burrs and flush with the inside pipe wall. These taps were connected via -inch copper tubing to the manometer board (Figure 9). Both mercury and carbontetrachioride under water were used to indicate the pressure drop. Care was taken to insure that the manometer lines were filled with water by poriod Ic flushing. The 6-foot copper tube was also used (62) in conjunction with heat transfer coefficient measurements, Part (Figure 7) depicts the section used for the 29 FIGTJBE 9 MANO}4ETER BOABD UNGEMENT 30 laminar viscosity and light transmittancy determinations. The main flow, indicated by the arrow, was in the vertical 1*-inch brass pipe. Glass capillary tubes of varying length to diameter ratios were inserted into the main stream by means of a steel fitting located 21 inches below the entrance and held horizontal by means of a spring arrangeent. The springs also served to hold polyethylene gaskets in place. The spring support mechanism was held in place by a 1-inch pipe cap. The pressure drop across the capillary tube was measured by a U.S. Gage Company gage attached directly across from the tubes. Table 1 Capi lar Tube Dimensions Tube Number A A-i C C-i C-2 D E Length In Inches Inside Dia!nete in inches x 10 Length/Diameter Ratio 11.95 5.30 11.93 12.02 5.92 12.00 11.93 8.97 1,944 1.944 2.580 3.588 3.588 3.588 4.092 5.076 615 273 462 335 165 334 292 177 The gage was of the stainless Bourdon type tube with an 8-inch face calibrated in one pound increments between zero and 30 pounds per square Inch static head. Addition- al calibration points were added to the face of the gage so that it could be read to t 1/20 pounds per square inch. The calibration was accomplished by checking the gage 31 against a mercury manometer under water pressure. A plot of the calibration data appears in Appendix . It was found that the calibration was linear except in the region below 2 pounds per square inch. Therefore all readings were taken with the gage pressure above that value, A 1*-inch needle valve inserted between the main sysiz" and the gage was used for throttling purposes1 The capillary viscometer was provided with a weighing cup of pyrex glass and a supporting platform adjustable by means of clamps. The volume of liquid caught in the cup was weighed on a null-point alance manufactured by the The balance had an accuracy of ±0.5 grams. Time of ef flux of the weighed volume of dispersion was measured by a stopwatch. The diameter of each capillary tube was determined by Welch Manufacturing Company. weighing the mercury required to fill the tube. v1easurements of the diameter agreed within ±0.4%. In addition, one tube was used to measure the viscosity of water to verify the mercury measurement method. The temperature of the flowing dispersion was measured by means of a copper-constantan thermocouple situated in a copper well at the entrance of the test section. The voltage was read from a Leeds and Northrup type K potentiometer. Tuperatures were kept within ±0.4°F. of the desired value. 32 The photoelectric emulsion evaluator was located 38 inches below the capillary tube viscometer and 59 inches from the entrance to the vertical test section. The eval- uator, which consisted of a light source tube and a photocell tube, was used to measure the amount of light traits- tted through the dispersion. This procedure was intended relate the light transmitted to particle size and flow rate and, in turn, to apparent viscosity. Figure 10 is a detailed drawing of the emulsion evaluator. The light source tube (8) was mounted on the main piping system (16) by soldering a brass fitting (14) into a 5/8-inch hole. The piping system and the light source tube were sealed from one another by the glass window (15) in the stainless steel light directing tube (9). A pack- ing gland (13) was forced into the stuffing box by the fitting (12). The light supporting tube (8) was soldered to piece (10), and this combination was held to (12) by three brass screws (11). The end of the light supporting tube was closed by a micarta end-piece (3), held in place by binding post (2), which also served as a ground connection. Two light power supply binding posts (1) and three lamp adjustment screws (4) were fitted into the endpiece. The aluminum lamp base (6) and the lucite holder (5) could be moved along the adjustment screws to give the proper illumination from the lamp. 6 1 2 7 21 8 9 2+ 22 25 HALF SIZE FIGURE 10 LIGHT AND PHOTOCELL PROBES 26 34 The photocell tube was soldered to the main piping system directly opposite the light source tube by means of fitting (17), which was inserted into a 1*-inch hole. This tube was sealed from the system window (20) in the photocell supporting tube (24). The packing was held in place by gland (18), which was forced into the stuffing box by fitting (19). The photocell was fitted into a socket mounted in lucite (21) and was attached to the micarta endpiece (22). Binding posts (26) supplying the voltage across the photocell, were also raounted on the end-piece. The entire photocell mounting wag held in place by set screw (25). Packing for both tubes was constructed from teflon, The voltage source of the 6-volt, 2-pole light bulb (7) was a Delco 6-volt lead storage battery. The current was first -directed into an exterior electrical system so that a specified voltage, usually 4.5 volts, could be maintained at the light bulb. To insure that all data were taken under identca1 conditions, the voltage delivered across the light bulb was checked before each reading. i ransrnitted light received by the photocell tube (23) was converted Into a potential, which was measured by a null-point potentiometer. The galvanometer used to observe deflection was a Leeds and Northrup instrument, model number 2430, which is much more sensitive than those found mary potentiometer systems. The galvanometer was nal to the potentiometer system. The face of the galvanometer was calibrated from zero 100 in increments of one so that percent changes could be estiivated. When water flowed in the main piping system, the instrument was set to read zero with the light source off and 1OC with the light source on. Thus when the dispersion was flowing, it was possible to determine how much light was transmitted through the dispersion as compared to the ezaount transmitted through pure water. Sensitivity of the galvanometer, as it was used, was ±1%. The electrical system is schematically shown in Figure The symbols represented are as follows: Bi 90-volt battery (ICA VSO 90) B2 6-volt lead storage battery (Delco dry charge) B3 4 mercury cells (Mallory ZM-9) Cl Two sets of contacts for phototube (RCA 1P4 C2 Two sets of contacts fcr igrtt (GE No. 82, 6-volt) C3 Galvanorneter connections (Leeds & Northrup 2430a) Ri Coarse adjustment rheostat (10 turn 20,000 ohm Helipot Load resistor (1 megohm) Coarse adjustment rheostat (5 ohm rheo Fine adjustment rheostat (10 turn 25 ohm }ie1ipo Load resistor (50,000 ohms) R3 R4 R5 R6 HiH R8 B3 I S6 R6 / /! 31/ FIGURE 11 WIRING DIAGRAN FOR PHOTOELECTRIC EMULSION EVALUATOR R7 Ealancing voltage set potentiometer (10 turn 50,000 ohm Helipo RB Voltage resistor (10 ohms) R9 Sensitivity lowering resistor (50,000 ohms) PlO Sensitivity lowering resistor (1,000 ohms) P11 Sensitivity lowering resistor (50 ohms) Si Double pole double throw circuit selector s 52 Single pole double throw push button 53 Single pole double throw cell selector switch 54 Double pole single throw push button 85 Single pole single throw light switch 86 5 position sensitive selector and galvanonteter switch. To enable the investigator to view the dispersion as it flowed through. the system., a sight glass was located 6 inches below the evaluator. Thus if the dispersion tended to separate, it was easily noticed. Saruples were with- drawn from a sample cock located 17 inches below the evaluator.. Three unions were used so that each section of the ver tical pipe could be renoved independently of the others. The section containing the capillary viscometer was constructed so that it could be relocated in the iiain piping system to give both vertical and horizontal readings of the laminar viscosity. CHAPTER 4 EXPERIMENTAL PROCEJRE ral Discussion The purpose of this investigation was to determine the laminar and turbulent viscosities of an unstable iiqiid-liquid dispersion. The dispersion referred to was composed of a petroleum solvent, "Shellso].v 360," dispersed in water. Finnigan (17), working on the same sys- tern, showed that there was a definite limit to the compositions suitable for evaluation. The compositions investigated ranged between zero and (by volume) solvent dispersed in water, and pure sol- vent. For the dispersions, the water was a continuous phase and the solvent the dispersed phase. Flow rates were varied between 1 and 30 gallons per minute. Physical properties of the solvent as used in all calculations were those measured by Finnigan (17). The solvent was recovered after each run and used for following runs. The following pure liquids and dispersions were stud- ie 1. Pure water 4. 35% solvent 2. 5% solvent 5. 50% solvent 3. 20% solvent 6. Pure solvent The supply tank and main piping system were flushed h solvent several times before any runs were made, When the dispersions were prepared, a calculated weight of solvent was added to a previously weighed amount of water in the supply tank. The total weight was kept near 300 pounds in order to maintain a constant head of fluid on the pump. In order to obtain the most rapid mixing possible and to assure a quick turnover of the material in the system, all valves were initially left wide open and the tirrer allowed to run at maximum speed. The time necessary to achieve thorough blending of the two liquids depended upon the concentration of the dispersed phase. Mixing time was usually 2 to 3 hours, the higher concentrations taking the longer time. The dispersion took on a milk-white appearance characteristic of many liquid-liquid suspensions. It was noted that, if the stirrer were turned off, a clear layer of solvent immediately became visible at the surface of the sysin the supply tank. This separation indicated instaby of the dispersion. Even with maximum care, the interface eventually became contaminated with dust and small pieces of the flexible hose. The contamination acted as a stabilizing agent. However, the dispersion never reached a point where it could be cona±dered stable. Samples of the dispersion were taken periodically to 40 insure that proper mixing was occuring and to check the coiposition. It was found that actual compositions ineas ured were, in genera slightly lower than the nominal composition Table 2 Nominal and Measured Composition Nominal Volume % Solvent Measured Volume 1 Solvent, Average 5 4.8 20 19.4 35 34113 50 49.2 At each concentration measurements were made of the pressure drop across the test sections, orifice pressure drop, fluid temperature, rate of ef flux from capillary tube, and light transmittancy. After each series of runs the liquids were allowed to separate over night. The sdvent was then decanted off and used again in preparing the ext concentration. The water was discharged to the eewer. 41 Thrbulent Flow Viscosit Measurement The measurement of the apparent viscosity of the dispel ion in turbulent flow was accomplished by means of pressure drop determinations over a 6-foot, 7/8-inch O.D., 16 BWG horizontal copper tube. The piezometer lines were flushed periodically to insure that water was the only fluid in the tubing. The valve at the discharge point of the piping system (number 4, Figure 6) was closed, and noflow readings were taken from the manometers. The readings for the pressure drop manometers were always zero. The readings for the orifice manometers wore zero only for the water and solvent runs because of the vertical distance between orifice piezometer taps. The discharge valve was then opened to allow flow to begin, After a period of time to allow for the settling that had occured in the main piping system, pressure drop readings were recorded for both the orifice and the test section. These readings were taken simultaneously with the laminar flow measurements, Carbontetrachloride was used for low flow rates, mercury for high flow rates, and both fluids for intertu ediate flow rates. Fluctuations of the manometers were minimized by cbsdown on needle valves at the pressure taps and manom- seal pots. It was observed that the most fluctuation 42 occured at low flow rates, probably indicating nonhornogeneity of the dispersion. For very slow flow rates the flop was measured by means of the weigh tank. Periodic checks on the flow were also made at higher flow rates. The temperature was maintained at 70.5°F±0.4°F by means of the cooling water in the Jacket of the supply tank. Capillary Tube Viscometer To measure viscosity by the capillary tube method, the tube was inserted into the tube holding section and through a hole in the vertical pipe wall. The hole was slightly of the largest capillary tube. The end of the capillary tube was positioned so that It would be at the axis of the 1*-Inch pipe which carried the main larger than the O.D. flow. The temperature of the dispersion was allowed to come to a constant value of 70,5°F ±0.4°F, A tare weight was taken of the weighing cup before each measurement. Fluid was allowed to flow into the cup during a definite ime, measured by a stopwatch. Diring this time the manomtore were read periodically to get an average flow value. The pressure on the 8-inch pressure gage was noted in order to obtain the difference between the fluid and the atmos- phere, i.e. across the tube, 43-44 immediately after the run, fluid in the weighing cup was weighed, Hefore beqinning a new run, the flow rate and/or the static pressure head was changed. At each con- centration a series of runs was made with the different capillary tubes to determine the effect of diameter, if any. The majority of the runs were made with the capillary tubes in a horezontal position. However, because there was a different value of viscosity measured by each tube (very noticeable at the high concentrations), the apparatus was rearranged so that measurements could be made with the capillary tubes in a vertical position, Photoelectric Emulsion Evaluator Measurements with the either simultaneously emulsion evaluator were made with or immediately after ments with the capillary tubes, calibrated to read zero and water flowing. measure- The evaluator was always with no light and 100 with light After calibration the solvent was added to make the dispersion. By manipulation of the various rheostats in the ex ternal electrical system, a voltage of 4.5 volts was maintained at the light (Figure 11). The proce&re involved was as follows: 1. Set 4.5 volts across the light ohtind. was value steady a until continued were r.dings the with chazyo trensittartcy iew Ihe ixing. of t roi I recorded determine to frequently a1vancieter readings the runs, cf seri each cf heinnirc! the At apar tie l/2C prohos the with iade rins several were there mrt, l/r3inch probes the with :iade were ohservatior's the of ty najor- the hi1e rate. flow of ftinction a as changed transittancy hether erine Lc rates flow various at taken were readmnçs .hese water. the thrcuch tranarnitted light the of percentage a h to calculated were di*persion the with cThserved readings the water, with lOU to fron read to calihrated s cjalvanc:oter the 8ince ro off, t ±} 1 with çalvanc:eter Read and on, iQht 1 with alvancicer 1?ead 3 CHAPTER 5 SAMPLE CALCULATIONS Physical properties of the petroleum solvent and wa er are discussed in the appendix, as are details of calibrat ion. Capillary Tube Calibration and the Laminar Flow Viscosity The bore of the capillary tubes used in the invest gation of apparent laminar viscosity was a critical factor in the calculations. Utmost care was taken to get accurate dimensions, since the radius of a. tube was used to the fourth power. Mercury at room temperature was drawn into the bore f a capillary tube, which had previously been tared. The ght and length of the mercury column was found, and the jus of the tube was calculated by means of the following equat ions: V= wt and 1° wt (77)(L)(,,o )(2 47 where V is the volume in cubic centimeters, wt is the weight of mercury, grams, r is the capillary tube radius, inches, ,P is the density of mercury, g/cc. the calculation for capillary tube E For example, wL was 13.53 g/cc, and L was was 4.2069 grams, 34 inches, was as follows: (2k) 4.2069 r / \j (3.14.6)(13.53)(9.34)(2.54) 0.0254 inches Once the radii of the capillary tubes was established, it was possible to measure the apparent viscosity of the dispersion in laminar flow. This was accomplished by use of the equation derived by Poiseuille ,Ia (23) (TT)(P)(e)(r)4(p) (8)(L)(wt wh a P is the apparent viscosity, cp, is the pressure drop across the tube, psi, e is the elapsed time of measurement, sec, L wt is the tube length, inches, is the weight of the dispersion collected, grams, p is a conversion factor, 1.043 x i8 (g)(cp) (1b) (sec) (in) 4 Data obtained for run 35-27 with tube E, length 11.925 inches and radius 0.0129 inches, was: weight of efflux, 116.3 grams i P 10.9 psi 300sec e (23a) Pa _! 416) (10.9) (300) (O.0129)(1.043 (8) (11.925 116.3) 2.670 cp For vertical tube calculations one inch of fluid head was added to pressures read. To insure that all measurenents were taken under lainmar flow, the ReynoldE nuin.ber was calculated for each tube. (24) ReT (D)(u)() = (4)(G)(p) (7T)(D)(,L/a) 24 where D u p is the diameter of a capillary tube, inches, is the velocity of fluid, ft/sec, is the density, lb/ft3, a is the apparent viscosity, cp, G p is the mass flow rate, g/sec, is a conversion factor, 39.37 (in)(sec)(cp/(g). Again for run 35-27, 49 (24a) Turbulent Flow Viscos The pressure drop across the 6-foot copper test section was determined by means of manometers, using carbontotrachioride and mercury under water as the manometer fids. The pressure drop was measured directly in mliii meters of manometer fluid, and the readings were changed pounds per square foot. (25) J°Hg )H2O p iPf the pressure drop due to friction, psf the millimeters of manometer fluid is a conversion factor, 3C4.8 mm/ft p A sample calculation: (25a) (843.46_62134)iumHg 304.8 The friction factor was found by using the equation: f (26) (LPf)(g)(D) (2),P )(u)2(L) e (77)2(zPf)(g0)()J (32) (L) (W)Z 50 is the density of the medium, 1b/ft is the diameter of the test section, is the length of the test section, is the mass flow rate, lb/sec. For illustration, run 35-27 will be used again. LPf was 99.92 psf and W was 1.06 lb/sec (from Figure 12) (26a) (3.1416)2(99.92) (32.17) (57.6 2)(6) (1.06)2 f ) (0.06 2 = 0.00785 The turbulent flow viscosity was calculated by f it- g all the data to Equation (4). ng 1/ '[ me versus log wif, This was done by plot- This plot will yield a straight when the viscosity is independent of flow rate. From o smooth curve drawn through the data, the viscosity at each flow rate was calculated front the following: Re 4W D,JJp7T 1 4.0 log (4)(W)([7) (7T)(D)(Jia)(P) -0.4 where p is a conversion factor 6.72 x 10 and is the apparent viscosity. lbjft)(sec)(cp) 5]. 8 I 0.1 I I I iiiil1.0 I J, LB/EC FIGURE 12 PLOT TO DETERMIIE OW PLATE 52 illustration for the with i/f S% dispersed phase series equal to 11, WW equal to 0.0821, and W equal to 0.9022 is: (28a) 11 4O log froni which 4) (lO) (0.0821) - -0.4 .1416)(0.0621)(6.72) (j'a) 3*534 cp This correlation was made for a number of points for 1 concenttations, and the values forjUa are plotted against flow rate, giving the relationship of apparent vis cosity to shear rate. 53 00 o PURE WAITER PURE SOLVENT SOLVENT , 5% 0 400 ., 20% SOLVENT 35% SOLVENT x 50% SOLVENT // /< 13 0 1 000 12H 0. /0 0 / 0 // e 0 CC / 10 0.03 0.10 0.05 LB ' FIGURE 13. PLOT OF 1/f VERSUS 0 20 / N N N i'4) km Posit 2te ystoz io fcrat in capi1 e Ct Su:iarj 1, try !eyno1da e the Ly caicilated wriç cf visccitie to 1CC te sh is data lazy fv rancleQ niauib.r- cap the In nuibers Reyxtolds ar 2) (qtiaticr equaticn isa's visao6itie The deteriix c used were ear Poie of 3ion3. shear the of 1xth frctor a thai cLserired. Lavo , (Ch.atter after ec1id with mis- i f]iw were dte 3 tuhe the of and viscosity parent rate the dipersior Uqiid riieters, ii x cf t( :an:, tuJi p*.icns. the for Cap1iar os Li Vigci '7 fl2w AJ1*T, r Table 3 (Continued) 351 Dispersion N I, 0% Dispersion N N N N :6 C-2 0 E C-2 0 E C-' C-2 7 10 17 8 24 19 5 6 3 10 N 0 E 8 Solvent N A IV Wat e 10 C-2 4 Horizontal N N Horizontal N N Vertical N N N Horizontal N Vertical Nor izont a: Figures 14 and 15 show results obtained from the capillary tube measurements. The apparent viscosity of the pure components and dispersions are plotted versus the calculated Reynolds number in the tube. In addition, ranges of viscosity measured under turbulent flow conditions are indicated by vertical bars. These figures do not take into account any effect produ.ced ky the flow condItions in the main pipe. Figure 16 shows that flow conditions in the main pipe have no effect on the viscosity measured by the capillary tubes. Figure 14 shows the results for water and for the 5, 20, and 35! dispersions. Figure 15 shows the results for pure solvent and the 500 dispersion. Figure 16 shows laminar flow viscosities, which were measured at constant 3.6 v4/t FIGURE 1 LA4INAR FLOW VISCOSITIES OF WATER, 5%, 20%, AND 35% 3.2 DISPERSIONS TUBE A 0 o TUBE B 0 2.8 3 TUBE C TUBE D SOLVENT , HORIZONTAL , HORIZONTAL , HORIZONTAL , HORIZONTAL v TUBE E , HORIZONTAL x 'rUBE A..1, HORIZONTAL D TUBE B , IERTICAL D 'rubE C-2, VERTICAL TURBULENT FLOW VISCOSITY RANGE 1.6 20% SOLVENT WATER I 0 2 I I I I I I 8 10 12 REYNOLDS NUMBER IN 'rUBE X io-2 6 5.8k U - i'W3E A , HORIZONTAL , HORIZONTAL , HORIZONTAL , HORIZONTAL , HORIZONTAL TUBE C-i, VERTICAL A TUBE D , VERTICAL TUBE B , VERTICAL EIJ TIJRLULENT FLOW VISCOSITY RANGE I U o TUBE TUBE 4 TUBE o TUBE U D ----"T 5.0 __ £ A 5O .6 - A SOLVENT B C D E 4, 3 1.2 SOLVENT 0 . 0 0 . 0 Qf4 G 4, S S 10 1]. 0.8 1 2 3 4a IN CENTIPOISE 6 8 7 REYNOLDS NUMBER IN TUBE X 102 5 FIGURE 15 LAMINAR FLOW VISCOSITIES OF SOLVENT AiD 50 9 DISPERSION FIGURE 16 EFFECT OF REYNOLDS NUMBER IN PIPING SYSTEM ON MEASURED LAMINAR VISCOSITY WITH CONSTANT LP ACROSS CAPILLARY TUBE TUBE D o TUBE C Cl Uk3E C W3E C - e TUBE A - 35% SOLVENT 35% SOLVENT 5.3 PSI - 6.2 PSI 5% SOLVENT 5% SOLVENT - 9.6 PSI 20% SOLVENT - .1 PSI 3.8 psi LP WITHIN C U 8 10 15 20 REYNOLDS NUMBER IN 1INCH PIPE X 25 35 59 the Reynolds numboz- in the 1*-inch standard pipe which carried the main flow. This figure shows that the viscos- itie8 measured by the capillary tubes are not affected by the flow rate in the main system, and this factor, therefore, need not be considered in the analysis of the data represented in Figures 14 and 15. Other workers (51, p. 571; 30, p. 135) have observed that apparent viscosity tended to rise with increasing flow rate, indicating dilatant behavior. It was also ob- served that the viscosity, as measured with tubes of different diameters, resulted in different values, generally increasing with the diaraeter. This was most evident with the more concentrated dispersions. This effect, which has also been noted by previous workers, has been named the Sigaaeffect (15, p.-1074). Vand (57, p. 277) explains this phenomenon by assuming slip at the tube wall. Figure 14 shows that, in the experiments with the 5% dispersion, tube A gave viscosities about 7% below those obtained with tubes B and C. }iowever, no significant difference can be observed between tubes B and C. It can be seen that the viscosity data begin to scatter somewhat above a tube Reynolds number of 1200, probably because of incipient turbulence brought about by vibrations in the flow system. This was also noted with the 20% dispersion. 60 Tube A-i measured low viscosities with the 20% dis-. persion, giving values about 15% below Curve I, which represents quite well the data for tubes ]3, C, and D. Data for tube B lie somewhat higher than Curve I, could be due to agglomeration of the This solvent particles and a resulting plugging effect, It was observed that dis charge from tube B was somewhat erratic, indicating the possible presence of slugs of solvent and water. This plugging effect may occur within a certain range of diam- eter and length for each concentration. It was observed for the higher concentrations that viscosity measurements were impossible with the smaller diameter tubes. The 35% dispersion showed the first really significant change of viscosity with tube diameter, The values for tube E were 12% above those for tube D, and those for tube D were 5% higher than those for tube C. showed some viscosities, which may Tube B again c been the to a plugging effect. The effect of capillary tube diameter on the measured viscosity was also apparent with the 50% dispersion. Tube E gave results about 10% above tube D, while tube D gave values 5% above tube C. No results were obtained for tube B. easurements made on the solvent showed a slight 61 increase of viscosity with flow rate, as measured with tubes A and C, while tube E gave a fairly constant value. At the lower Reynolds numbers deviations in measurements were about 10%, and at the higher Reynolds numbers the deviations were about C Figure 15. from the straight line shown in Since tube A gave consistent results when used to measure the viscosity of water, the discrepancy was in- explicable, However, Lindgron (30, p. 135) and Reynolds (44, p. 84) noted that at times the viscosity of pure wat- er increased linearly with flow rate. The pressure gage was recalibrated (see Appendix E) to determine whether an error in pressures read could be the reason for the rise in the calculated viscosity. Although a slight change in calibration was noted, the error was not significant in explaining the result. It was decided that the sigma effect may have been due to other effects besides slip at the capillary wall, The fact that the tubes were horizontal led to the conclusion that a "settling" effect could give apparently erroneous results. The settling refers to a two-phase separation in flow. Therefore, runs were made with the tubes , C-i, C-2, D and E in a vertical position on the 20 and 50% dispersions. Figure 14 shows no significant change in data under this condition. However, FIgure 15 shows that there is a definite change in viscosity values 62 for a particular tube, in general, greater values being obtained in the vertical than in the horizontal positions, The difference in apparent viscosity, as measured by the individual tubes, remained proportionately the same distance apart. This could be explained by a settling effect. In horizontal flow, settling would cause layers of solvent and water to form adjacent to the upper and lower portions of the tube, respectively. The measured viscosity would then be lower than if no settling had occurred. These data also indicate that the sigma effect was not caused by settling, It actually might be du to slip at the wall, as theorized by previous workers (60, p. 600). 8ifficient data was not obtained in the present experiment to corroborate this theory. The laminar flow results on dispersions show a slight increase in viscosity as flow through the tube increases. This indicates that the dispersion is non-Newtonian a.nd is slightly djlatant in laminar flow. Metzner and Reed (37, p. 434) defined a characteristic quantity n', which is a measure of the deviation of a fluid from Newtonian charac- teristjcs, The quantity n' is defined as follows: (29) Wier e V is the volurftetric flow rate, ft.'/sec. If a plot of lo (D)(P)/(4)(L) versus log (8)(V)/(Tr)(D)3 is a straic line, n' is consta and the fluid oheys the power law as expressed wtoniar; when ii' is less than 1, the fluid is pcoudoplestic; hon n' is greater When n' the fi'i±d 1 than 1, the fluid is dilatar Fiqure 1? i a loç-loq plot of (A.P)(D)/(4)(L) versus (8)(V)/(7fl(D) for tuh'o !, 5 dispersIon, tu.Le D, 3S dispersion, and tuhes C-i and C-P, 5C dispersion, Lin*s having a elope of 1. [.7 iay he drawn through each t of data. These irciicate that, under laainar flow cortd tions, the dispersions are .±ht1 dilatant and the value of n' is contan for all concentrations of solvent up to 5, These resui.s also verify Figures 14 and 15. It is siqnificar;t iLt S experiient verifies the work of other e eriienterz with solid-liquid dispersions. While the data here is not sufficient in itself definitely to conclude this verification, it does sen. apparent that the equaticns and theories derived for the solid-liquid dispersion 1old for lqui-liquid dispersions. 6i- 1.0 4__' 'J. (.I o ° 0.1 TUBE C-i, 50% DISPERGI0I L'uBE C-2, 50% DISPERSION TUBE D, TUBE B, 35% 5% DISPIRSION DISPERSION 1.0 5.0 (8)(V) , (7T)(D3) SEC FIGURE 17 SHEAR STRESS AT CAPILLARY WALL VERSUS RECIPROCAL SECOIDS 65 Turbulent Flow Viscosity The turbulent flow viscosities were measured by means of pressure drop data over a 6-foot, horizontal, 7/8-inch O.D. copper tube. The values were calculated by determin- ing the friction factors in the test section and by substi- tuting the values into Nikuradse's equation (Equation 4) for smooth tubes. As explained earlier, all data were plotted according to Figure 13 and the viscosities calculated from Equation (4). Figure 18 shows the calculated viscosities as a function of ftow rate for the various dispersion compositions and pure components. The solid lines represent the values obtained from the present work; the dashed lines represent the values obtained by Wright (62) during heat transfer coefficient measurements. For a Newtonian fluid the plot of 1/ f versus the log W f should have a slope of 4.0 if Nikuradse's equation holds. In Figure 13 the line for water, which was calculated from Equation (28), agrees well with the experimental data for water. The line for pure solvent is a least squares line with a slope of 4.0. The viscosity of 1.05 centipoises for solvent at this temperature, shown by this line, agrees well with the value of 0.98 centipoises measured by Finnigan (17). The dispersions reflected a definite dependence upon 10 o CALCULATED -0M REFERENCE (62) 50% SOLVENT 20% S0LVEIT SVT S 5 SOLVENT WATER 0.0 1.0 2.0 3.0 W, LBm/SEC FIGURE 18. TURBULENT FLOW VI3COSITIES AS A FONCTION OF FLOW RATE 67 flow rate, with the apparent viscosities decreasing with increasing flow rate. plastic materials. This behavior is typical of pseudo- The majority of suspensions tested by other workers, although mostly solid-liquid in nature, exhibited this sam.e pseudoplastic behavior. Finnigan (17) found that the same system investigated here exhibited dilatant characteristics under turbulent flow. However, since Finnigan's measurements were aade with a vertical test section, a settling effect in horizontal flow may explain the difference. it is possible that the phases separated, because the dIpersion flowed horizontally. McDowell and Usher (35, p. 574) suggest that this type of separation could account for pseudoplastic behavior. Conglamoration of globules also tends to decrease the apparent viscosity. Another theory (60, p. 595) is that the discrete particles tend to align their major axes to the direction of flow, thus causing the viscosity to decrease to a limiting value. The values obtained in this experi3lent then agree with the majority of observations rtade by other workers on suspensions. This again would lead to the conclusion that liquid-liquid dispersions do behave in a similar fashion to solid-liquid dispersions. upirical equations were developed to describe how the viscosity changes with concentration of the dispersed phase 68 at flow rates of 1.5, 2.5, and 3.0 Ibm/sec. These equa- tiona were derived by a least squares method, assuming the form of Equation (6) 1+2.50 + 2 cz5 + The results are: = 1+2.50 (31) - 10.730 2 + 60.920 for a flow of 1.5 ibm/s 12 l+2.5qi ($2) 2 + 46.36ç for a flow rate of 2.5 ibm/sec, and 1+2.5 - 11.20 for a flow rate of 2.5 ibm/sec. The data for the individual flow rates have an aver- age deviation from Equation (31) within ±8, from Equation ($2) within 2.5%, and from Equation (33) within 8%. For convenience these equations were averaged to give one equation applicable for all flow rates within art average deviation Of 9.5%. (34) Equation (34), in a form C l2.5cb - Ii.OiØ 2 + 52.620 of the Einstein equation, reduces to it at low concentrations. :9 Ftgure 19 shows the quantity,/J/J/ plotted versus the dispersed phase concentration for the equations derived by several workers, It also shows the viscosities calculated in the present experinent and their relation to the equations presented. Equation (34) and the equations of Vand and Ioscoe show rdatively good agreeient with the experimental data, Other equations shc'ti wide deviations at the higher concentrations. Photoelectric Emulsion Evaluator The evaluator was inserted in the vertical 1+-inch brass pipe perpendicularly to the flow. Two types of measurements were nade: variation of light transmittance with time of mixing and variation of light transmitted with flow rate, once the dispersion was formed, The probes were 1/8-inch apart for the majority of the runs. One set of data points was obtained, with the probes 1/20-inch apart. Figure 20 shows how the percent of light transmitted varied with the length of mixing time for the dispersions. The percent of light transmitted refers to the amount of light received iDy the photocell probe compared to the 6mount of light transmitted through clear water. The 70 8 7 A B C D E F c 0 - EIIERS EQUATION VAliD EQUATION 2 1+2.5Ø_11.0].252.62Ø3 - ROSCOE EQUATION FINNIGAN EQUATION - EINSTEIN EQUATION W 1.5 LBm/SEC W 2.5 LBm/SEC W 3.0 LBm/SEC 3 2 1 0,0 0.1 0.2 0.3 VOLUME FRACTION SOLVENT 0.ls FIGURE 19 PLOT OF VAJIOTJS DISPEBSION EQUATIONS 0.5 100 FIGURE 20 AMOUNT OF LIGHT TRANSMITT) AS A FUNCTION OF MIXING TINE 80 0 % 60 3% SOLVENT o 20 SOLVENT 20% SOLVENT 0% SOLVENT 00 0 20 o +O 0 0 60 80 TINE OF MIXING, SECONDS 100 120 72 percent tranamittancy dropped almost immediately with mixing time to a constant value, indicating formation of the dispersions. the rapidity of The dispersions were charac- terized by an opaque, milk-white appearance, show the The data apparent consistency of the dispersions at a par- ticular flow rate. Figure 21 gives the relation of light transmitted to flow rate past the sensing probes, light tendency for the percent There seems to be a transmittancy to drop with flow rate for the 2O7, dispersion at a separation of 1/20- inch, which is not apparent at the 1/8-inch separation. However, with accuracy of the evaluator being ±1%, there is no conclusive proof that this effect is true. The percentage of light transmitted, in general, decreased with increased concentration of the dispersed phase. The 35 and 50 dispersions gave approximately the same values, indicating that there is a point where the amount of light picked up by the photocell tube is independent of concentration, This conclusion may be inac- curate, because, as the concentration increases, there is a secondary scattering of the light lost at lower concentrations. This light may then be picked up by the photo- cell tube. It was hoped that the evaluator would give a definite trend for the amount of light transmitted with flow rate to 100 35 0 0 0 0 WATER AND SOLVENT 1/8-INCH SEPARATION 5% SOLVENT 20% SOLVEN', 1/20-INcH SEPARATION 20% SOLVENT, 1/INCH SEPARATION 35% SOLVENT, 1/3-I1IcH SEPARATION 50% SOLVENT, 1/8-INcH SEPARATION 30 H 0 n no n S. 15 I 0.0 1.0 2.0 W,L /3EC U FIGURE 21 EFFECT OF PlOW RATE ON AMOUNT OF LIGHT TRANSMITTED 3.0 74 show how the particle size varied. It was expected that if the particles become smaller, leading to an increase of interfacial area, the amount of light refracted would increase with the overall result of a drop in amount of light transmitted. If this phenomena occurred, its effect was probably too small to be detected by the photoelectric evaluat CHJWER 7 CONCLUSIONS A study has been made of the laminar and turbulent viscosities of an unstable liquid-liquid dispersion cornpo5ed of a petroleum solvent and water. Iminar flow viscosities, measured by means of a nuraber of capillary tubes, varied with tube diameter, tube length, and flow rate. The variation with tube diameter, known as the siama effect, may be caused by slip at the wall, It was shown that it was riot caused by a settling effect, This sigma effect was more evident at higher concentrations, where higher viscosities were measured with tubes of larger diameter. The results are in agreement with results on solid-liquid nulsions. It is evident that the capillary tube method is not suitable for determining dynamic laminar viscosities of these dispersions, In laminar flow the dispersions behaved in a dilatant manner, with the viscosity increasing slightly with flow rate through the capillary. Viscosities measured in turbulent flow indicate that the dispersions behave in a pseudoplastic manner under these conditions, with viscosity decreasing to a limiting value as flow increases. Behavior of this system was found to be similar to that of many solid-liquid suspensions, and 76 it appears that similar equations are applicable to both. The equation of Vand (Equation 9) and Roscoe (Equa- tion 14) for predicting the viscosity of suspensions agree reasonably well with the present results. In addition, an "pirical equation which reduces to Einstein's equation at low concentrations was derived from the data. This may be used for predicting virosities of the syst studied. (34) l+2.5çb -ii.oiØ 2 +52.62Ø Studies with an emulsion evaluator showed that the dispersions formed very rapidly after mixing began. The percent light transmitted through the dispersion was a function of concentration up to 3$/ solvent, after which the percent transmittancy remained constant, probably because of secondary refraction. It was impossible to de- tect any variation of light transmittancy with flow rate past the light probes. CHAPTER 8 RECO'1ENDATIONS FOR FURTHER WOIC The investigation which has been reported in this thesis has developed the groundwork for furtber study of liquid-liquid dispersions. Several suggestions for futire experiments are: 1) Determine the effect of length of capillary o visconieters with constant diameters in the measuremont of laminar flow viscosities of the same and other liquid-liquid dispersions. Devise a method to measure the viscosity of similar systems flowing in the transition range between laminar and turbulent flow Extend the range of turbulent Reynolds numbers for the present dispersion by employing a larger pumping system. Use a. photographic technique in conjunction with the photoelectric emulsion evaluator to measure the exact size of the dispersion particles. amount of light transmitted through the dispersion related i the time of mixing can define the concentration of the dispersed phase at small increments of the concentration. Repeat the present work, revising the dispersion Determine whether the 78 syzten by adding a stai1izinc aç-en to deteriine the effect of staJiIity on the phica1 propertiea. GiL PT,I A1VeS, Ge . 2. Bec}ir, Ne :'..OfliT :;T'siors. 56:1O7-9. 19+9. F:ic.>w of flOfl ::or1rig Ch:ic: mi1s1ons: York 31tih:1d .rctico, theory 1957. nd I BrouL:hton, C, 3I.2p, ic viscosity of oi1 u1res. in-tcr cusicLs, +2:253-63. 79 9 ic1 (7; stry JournI 1938, Unit Urticns, Br'r, G, G 6ilo. Chirig, P, Y. 11. .. 1955. Sch- chi, or vs.lidity of the ::instein vLscos law of sei ticn. Journ I i6:193a. 1955, Dc 13r.:Lin, k. iYEr $cience .spenslofls rnd Nature l6: 220-22. 19+%. icit Q zi (I spheres i: 1+8563_3. I ae Ch. - 1951, Dro, T. 13. nd J. W. Ioopes, Jr. Vol. I. ++8p. Duclaux, J. D, tor ccr E1flStOj!: inc nc. 12. Eirsteir BeSt In 3+: 591- L T. . erie jO1C 1911. Isor cJ.e1u1dimen- der der dvar.ccs in chc'j. ic ross,19t.. Journrl Dc Chile 4'ysique Yiskositt Ellers, II, tofrc 1s Zeit schrift S1ore c- .0 L. 1932, 28:i1.i6, the rd Stole's (36. ZU ojner .r :it ic'nsionen, 3904. ine neue .in. 1c dcx' rhyik rrcth2, Koiloid irich, F. ,N. l3unzl cnd ii. Zejtschrjft 7:276. 1936, Die Vicott Von Tlscnsc.i1tz, F, onsior. es Iticcit r Tc1sben uno 1 r Reuibrutn:. Zeitechrit fur Choi.je t t.n durch ilsehe J15;P:73-9o, 1931, . L , Whitmore EVSOn , &. F. , 80 Use of coaxie1cv1i(Cr vi sc.rtors and c:;ijT :oo-tube mture i6: meters for sospns:.or;s, 16. Eveson, G. F., S. , colloids T' Psittf1, cc;Ls, TISES 3. J. i' fo o circulc: tubcs, J2rc.ssu - tt 19. 21, 1c.E' liuuic 1 ir phase , , irnö'y Society r.ict1ons 9:8O-92, Hatschek, I, Die Visc'sit'at von erehen-. KoiioiJ Zeitscbri 163-5. 1920. Hu1ns, i, L, The v1scosiy T.o!1.te soltions of Suspen sionen. lonE-oh omn molecules. +2:9i, 1938. Jourr :1 22. Joshi, S. F. 1hysicv1 Chemistry Viscosity of reversjblc? cnuisons, Faradcy Society Tronnctiors. 20:512. 192+. Knudsen, J, G, ar:cl D. L, itz, r101C nd HCEt Trensfer, ork .cC:rn-i1]. 576p, Krieb1.e, J. G. . C. :..tye11, The vi:cosity of tcP N ojst c, d 1te t J i i Teti1e Fosenroh Jourrid 19:253-.258. i.ay 191+9. 1F 214. in t is, c Dcç. 1958. 15'- numb. 1ves. Rappel, J. Viscosity of susp:nsions of uniform spheres. Journ1 of App11c hysics 28:12fl92, Nov.,1957. Hatchc. The nern1 ieor:; of vIscosity of two1913, 20. c' 1 Tsses anc. hoot tsf (.:ro'' Stote C11c o, CcrvIlis, Oco 18. cicty Jiscssions 1951. for L. Whjtor I. ou viscosity in j.o ditribu;i.n: C1E5:jc; No.11 :1L 1950. C Knitz , F, .n btween icos ourr. 26. 1 ;tt.ons rijd Vc1ue of sioute, y..o1o:y 9:715-25. 1926. :C efiective vi SCOS.T of H.ms:.orj.s , rof 1. 'tcle, xrofe I eiety .f (:,C.rr.t }ync., . F. of 3 ' ic I (London). ..237:90-116, 27 Langloise, G of :utcrftc] 1 ti riis1Ofl. 25:360-63, r 1956, rid S. F, Gui1h:r..' in nst 2etc.. -. cv1(w of 1951+. cientiic 1. 28, Levitori, A. and A. Leighton, Ii 81 for the relati ii1 Lon : ts Viscosity relatonships ilk ft. Journd of hysic1 2s,r s contin Chsistrv 1+0:71-80. i)3(. tI. K., L. Squir .::.d . 1, Lo.;on. CoiiiJ1 29. propertiss of ciiy n.icrs, Lrnsctior1s of the inj.rc r i rs ll+:38-52. r 1935. r' r ic] Irdrcn, F. B. The trnItion cr:css .nd other 'Orci Pifl jfl V]5C0L5 iOW, irki fr Fysih 12:1-169. rr7 31. 1an1ey, H. St. 3. an S. 0. .;sor The v2cosity of suspensions of rher.s: A 'L Le LcLe 1ntcractior eocfLcinrts. ( :i: i :rr1 of ChemIstry 32. Mardles, F. r rnaquc s 36:1007-17, 32:763-7. , 19 of s. 3, The viscosit t iIds, ons In r tctions 191+0, The Wbjt3....or 102, L( itv . offect and ,oui of 1956. 3, 0, ::njth. ynjt o::.tion of crk, c1r...-Fii1, I . 3%. NoDovci..1, 0, 1, >r d F, L, Ushr, ir susr.r Viscosity and ridigity of fine ps.tic.L: s II on-&ricous SUf; nsions, Roynl 3ociet.- of Lorc.'or: Prccecding A131: 561+-7, 131, Jerril..., , F, hasis In the vIsc ctry of non:Ieutoujn f1nic.s, ISA JoirnE1 2:1+625, 1955, 37, Ietzner, A, B, and J, C, F1c* of nonNeton1.n fiuid-cori' th 1. .ninr, transition , rd turbu1t-.iII. ro.;:ors, ..eric; n Ir'3tiL to of C ic 1 1 ers Journd 1:31+1+O, 82 . 1955. iller, . . and C. A, ann. .itrtio of twophase syst.s of :. .isc!be liçiAcis, ;:ricn Institue of ChesricrJ...........incers iTWSCtjLfl5 ic;: 1+Q:709-.'+5. Nara;nasry, B. N, and h, .tscn. Petrol-water a, Journ] of t Ti IsLtute of 8cience 17A(vi):75-81, 1+0. 1931+, ClIver, 1), B. and S. G, ard, Relati.onohlp bet'ieen r.ive visco ty and voLr:i conccrrtion of stai.1e sus:enions of s oricol prtcies, 1953. 1+i. Cincy, B, B, and 0, , .1crs; 001'). e fluid propertias, jcr. . l9+7, 1+3:1+73_80. Cn1son. Iti I I rture 171:396-7. I-o.?r and absorption c ' s os and in rir.g - roress Orr, C Jr. C, h1ocer, The viscosity of si is a ercs, o r- I rf o1loicJ Science 1O2'-3, 1955. 1+3.. Pcrry, J. H, CeL.led h.:tineers' Ne 144, York, NcQra-Ai1J. Reynolds, 0. 35:81+. 1+5, 1+6, 147, 1383, I 1 r. T.h.....1co': 3rd. Nd. 191+2p, rety ceedings, Riohrc.scn, ;. C, Jber die Vishasitt von Emulsionen, lolloid eitschrift 65:32-7. Richardson, T. C ournai of Colloidal Science, 8367-..73. 1953. Robinson, J. B, Studias of Lho 1.isccsity o1 coiloids, I, Tc anor, bus vi:rcosity o1 dilute nr.uns of tric prticbos. L Lccity of Toncori Procecdi's A170:519-50, 1939. Boiler, 2, s. and C. K, toddard, ViscosIty and of structur J s o i- a, Journel of hy&ILl C1 1+8:1+10-25, 191+1+, riIdity iistry lIoscoe, R, The viscosity of spheres. British Tournoi of 3267-9. 1952. s of ridgid susuc: AJ.i 83 yui Cs Sechs, D. Journal Do ChirniePhysicue 29:280-6, 1932. Sherru:t The inf ei;tJ. s: C;n industry, 52. Sherizn, 53, 5tt, $tudles In :nter-in-oil o: u1.Loi., I, co cf Tjs;ersod i:.hase Cu ocuntr; ticn cc :ity, J ou.rn.u1 Of th Jociety of on Thez:±c :o, 2, 69:571-5. 1950. ie inflicuce of irtr: nha o. Vicosj on cty of CoiCrc ter-r-(11 S1oDs, Koi:c.;la-zejtschrjft ia :6-n. 1955. Slbreo, J, 0, e vi.eosity of o:uJ.sions, Part 1. - Farady Society Tailor, C. I. 26:26-36, 1930, The vi:cosit,r drops of nothcr fi Proceedings A138:'-i-.. 1932. in(:,, !, P. and . , .. of a fluid contirir s: a 1 Lcciety of I nCon ue..bers, The V1SCOni oth :r idiçri SU$pO$iOflS of srheric;1 paitc±' In ii rc in0tit to of Engineers Journal 3:111-16, 1957, icsl flF Treyi;l, R. E, iu -iin:nsfer (;prtions, New York, NcUraw-niii, l95, 400p, Vand, V. Viscosity of soitions and nsa.ons, Journal of Physical CherIstry 52:277-99/ l9+, Verre1en, T. , C., r I , agita.;ion. Ce.n.jca]. 1955, 'Il1ins, nd C 1i,id-1i i .......: 1g1ois. s-lj id .ncerinLnrcfress 51 :85F-9+F, Ward, S. G, and R. 1.. Jhitnoro, ritish Journal Applied Physics 1:284-90, 1950, 6o. flow. Iud:strial Non-:;ewtoriian flow, 195I. Industrial Iikinson, . 1., Ton-:cwtcnian 33:595-600, 1957. Cheimist 61. 62, WIlkinson, W. Ccn1st L 31:79_81+, rigt, C. H, Pres.L1rc dr liculd dimersirs In c.-!s, M.S. 120 flU!, len:VE:S, tui' Is (ir ( Ont tra:nsfcr of for 1iui iLi; in a circular tube, State 0cge, 1957. APPENDICES APPENDIX A NOMENClATURE It in Letter Symbols Meaning Symbol Units A Area ft2 A ft1 D Intorfacial area per unit volume Constant in viscosity equations Ratio of refractive indices Constant in viscosity equations Diaiueter of tubes or pipe F Force lbf f Fanning friction factor G Mass flow rate g Sec Mass velocity lb a B b ft (sec)(ft)2 g Gravitational acceleration ft Ccnversion constant, 32.17 sec (ibm) (ft) (lbq) (sec) Ii Volume factor I L Light intensity Coefficient of consistency Einstein constant, 2.5 Length of tubes and test section N Volume fraction in mixture r Capillary tube radius lumens cp ft ft 85 Units Meaning t Temperature u Velocity V Volume W Mass flow rate Greek Letter Smbo1s Finite difference ,IJ ,LJa d 7T p Time sec Viscosity Apparent viscosity Continuous phase viscosity Dispersed phase viscosity Limiting viscosity Constant, 3.1416 cp cp op op C lb Density SiTear force per unit area f Volume fraction of dispersed phase Interaction constant in viscosity eq.iat ion Composite Symbols BWG Birmingham wire gage in gallons per minute Logarithm (base e) log Common logarithm (base 10) O.D. Outside diameter of copper pipe 86 ymbol Meaning Un: Re Reyiolds number wt Sample weight g Pressure drop across test section lbf ft2 LPf Pressure drop due to fluid frict ion Subscripts Apparent C Continuous phase Dispersed phase Force (as in lbf) or friction (as in Medium or mass (as in ibm) o Initial Solvent Tube wail Water Limiting value Pf) APPENDIX B PROPERTIES OF FLUIDS AND INSTRUMENT CALCULATIONS Solvent and Water The solvent used was a commercial cleaning solvent anufactured by the SIteli Oil Company under the name of "Shelisolv 360." The manufacturer's specifications are given in Table 4. The fresh solvent, a clear, colorless iqutd, was used whenever possible. Although recovered olvertt took on a yellowish tint, probably because of impurities, it rained clear. Determinations made by Pinnigan (17) indicated that used solvent viscosity differed from that of the fresh solvent by less than Tabi Manufacturer's S.ecifications for Shel1solv 360 API Gravity, 60°F Specific Gravity, 60/60°F 49.1 Color, Saybolt 26+ Flash Tag, O.C, °F Flash Tag, CC., °F 110 Aromatics, Stoddard, 2 0.7835 103 88 Table 4 (Continued) AS Distillation9 °F: Initial Boiling Point Final boiling Point 304 10% Recovered 317 50% Recovered 323 90% Recovered 342 % Recovered 362 98.5 The solubility of the petroleum in water was quite low. It is apparent that the solvent-water systern used in this investigation represents a very immiscible pair of liquids. The densities of solvent as a function of temperature were measured by Finnigan (17) and presented on Fiqure 22. The density of water at various temperatures, obtained from Perry (43, p. 175), are also included. The viscosity of the solvent at various temperatures was alsc determined by Finnigan and reported along with the viscosity of water, fend in Perry (p. 374) on Fiqure 23. The density of immiscible liquids mixed together ±a an additive quality. Therefore, the density was calculated from the mixture law (35) 89 62.+ WATER 62 3 62 2 fJ f9.f SOLVENT t I I I L 70 60 t, I L O ibm/ft3 FIGIYRE 22 DENSITY OF WATER AN]) SOLVENT VERSUS TEMPEPLATTJRE 90 9.0 8.o H 7.0 6.0 I I I I 50 I 60 I t, °F .1 1 L 70 -" in lbm/(tt)(sec) FIGURE 23 VISCOSITY OF SOLVENT AD WATER VERSUS TPERATURE 91 where N5 is the voluue fraction of water and is the vo1uiie fraction of solvent in the dispersion. Eqi ipment The characteristics of tL.e turbine pump as described by the manufacturer are presen Led j :Ta,10 5. Table 5 me Pum. Charac iaterial odel Nuzber Speed fTonze LJ615 1750 rpm Delivered Flow, gp Total Head, feet of Water at 80°F 10 42C 250 110 10 40 The pressure gage used to determine the pressure drop across the capillary tubes was calibrated against a mtercury open leg uanoneter at the heginnin, and end of the experlinent. Figure 24 shows the original calibration (heavy line), and the rocalibration curve (dashed line). calibrations were within 6 the high pressures. The two at the low pressures and 1% at Since it is unknown where this devi- ation in calibration occurred, the old calibration values were used in all calculations, 92 OLD CALIBRATION NE CALIBRATION r-I Cl) 0 8 12 16 AC2JL PE1JE, PSI FIGTJRE 24 PRESSURE GAGE G LIBAiON CURVE 9 APPENDIX C TABULATED DATA The run number code Is as follows: The first number or symbol represents the nominal composition and the second number represent the run number within the series. Thus, 35-L is the fourth run with 35% solvent in water, ect. OBSERVED DATA (1) Run No. 5-i 2 3 5 6 7 8 9 10 (2) t, °F 69.9 71.0 69.7 70.0 68.6 69.3 Pressure tube tube ga ge, p si Position No. Horizontal. It It 70.3 1 70..5 15 '70.6 16 17 70.9 70.6 ft 18 19 70.6 II 70Jj 70.6 'I 20 21 22 23 2fl 25 26 70J 7Q5 70.5 7r7 70.6 70.3 27 28 - A 9.L0 II T1 ?1 1I IT I, 1! 'I It 10.00 A 10.00 A 9.95 A A A A A 6.75 8.00 8.65 10.20 8.20 B B B B B B 8.50 6.65 5.00 5.60 7.50 6.25 II Ti B B 1I 13 I' 10.05 B I, If 9.75 9.95 A A A A TI ?0.6 A A 13 1). 12 (5) Capillary 70,5 70.7 70.7 70.5 70.6 11 () (3) Capillary B B 5.55 6.65 6.65 6.65 6.65 (6) Light Intensity, - (1) Run No. We! ght (8) (9) Time of Orifice tube sec (7) Capillary efflux, Manometer, mm efflux, g 5-i 2 3 14 5 6 7 8 9 10 11 12 13 it4. 205.5 199.1 186.0 189.1 165.7 172.3 1914.14 171.6 161.7 1!4J.3 166.t4 181.2 196.14 23 201.3 205.8 165.0 129.9 121.2 163.5 161.2 153.5 139.5 214 163.2 15 16 17 18 19 20 21 22 25 26 1143.9 27 28 191.9 193.5 29 175.3 30 31 32 33 33A 314 35' 36 37 38 39 140 141 20-1 2 3 (10) 168.5' 1514.7 266.7 263.2 263.8 213.0 267.5 269.6 2142.2 67 (Hg) 142 (Hg) 720 660 86 io14(cCl) IT 814 (Cc114) 69 " 259 IT 660 660 600 / r o7 600 660 720 720 720 660 600 00 2140 2140 300 360 270 300 300 360 270 300 360 II 632. 113 (Hg) 57 " II 133 " 76 79 79 TI 131 TI II 53 (Cc114) 315 38 (Hg) 70 103 158 30 19 I, It TI TI It II 1414 135' 101 79 5' 'I I, IT 55' 2L0 216. 2 2L0 2614.14 300 300 2140 J. 14.63 ' 2140 2140 2140 2140 II 67 (Hg) 107 91 (CC114) 210 " " 360 300 360 360 300 2140 2140 66 52 206 193 88 128 127 ' 8 II 7)4 78 " 147 (CC114) 237 214 (Hg) 141 59 85 19 12 31 78 62 50 IT It 51 It IT 51 'I Si It 38 (Hg) Si 140 II I! II II IT 198( CC1L) 572 67 1 214 " (Hg) " 38 (0c114) 1461 66 (Hg 914 Manometer, mm 720 265.2 218.2 257.5 23.5 Test Section 1I N I, 71 (Cc114) 27 (Hg) II 36 53 26 28 27 II ' ' U 157 ( CC U ) 1420 14J4 65 " (Hg) " 148 (Cd14) 379 Il )Q (Hg) (1) 29 30 31 32 33 33A (2) 70.6 70.6 70.6 70.7 70.5 70.8 5) 31L 70.b, 35 36 37 38 39 70.8 70.9 70.5 70.' 70.2 C C C 140 70.1. 70.Ii. C C 141 20-.1 70 3 14 S 6 7 8 9 10 11 12 13 15 16 70.7 70.5 70.7 70.8 70.6 7o. 70.6 70.6 70.2 70.6 70.5 70.8 70,8 70,6 C C C C 19 70.3 20 21 C C C C 22 23 2t 2 26 27 28 29 30 31 314 35 36 70.9 70.3 70.5 70.2 70.J 70.9 70.9 3.20 L.90 I . .05 3.50 3.95 3L 30r o.1 3.90 - 5.145 - 3.50 7.00 7.65 9.10 21,0 - 2.j0 3.00 225 - 5.20 3.9 ID 6.00 0 A-I A-i * - 6.20 60 ID - : C D - 8:95 7.05 2.65 2.50 6.05 C C D D 21.0 21.0 20.5 * 0 70.L. 70,5 70.7 70.7 70.5 70.6 70.7 70.6 70.6 70.7 L.00 C 70.5 70.2 S )4 : & C 17 18 18A 7.30 5.80 B B C C C C C C (6) 95 : g 7.35 6,10 - 21.L, - - (1) (7) 20 -L 256. 2 2)40 278.8 99 S 21±0 111 (Hg) " 261±. 7 300 300 55 22 " 2140 149i 501 6 7 8 C, 10 11 12 13 1 ). 15 265.7 26L. 2)5. 8 206.5 202.2 (3) 300 300 51±0 196.9 L8o 23L.. S 203 . 3 201 1± L.0L L0 1±20 (10) (9) (Cc1L4.) " (Hg) (CC1,) 158.7 14.30 18A 89 89 2±1±. 2L0 291 (ccl 214.0 702 366 ", 711 506 " 598 395 " 214.0 2)40 373 150 2L0 393 20 21 22 23 2L 25 26 27 28 29 30 31 32 33 35 219.5 159.0 193.3 177.5 289.9 208.8 22. 2 293.7 326.3 255.1± 32.0 301.0 287.14. 160.5 171L.5 U 173.7 127.5 132.7 21i0 2L0 2L0 21±0 21±0 21±0 180 180 180 14.05 20 14.25 (Hg) 55 (cc114..) 92 576 3214. 583 U 114. " 356 31±7 LL9O" " 1±714. 597 500 1±93 " 14.80 :: " " " L85 2 214.0 88 62 21±0 122 81 100 119 1 .2 303.3 L.6 281±. 8 iSo 1±7 237.5 265.7 120 120 180 130 120 105 50 51 52 -,-) 21 . 7 255.7 239.7 90 (Hg) (Hg) U 129 107 1714. 208 i5L 192 239 2±8 " " " " LjLo (cc1 312 " 68 (Hg) iLLS I? 14.67 14.39 14.68 LL L2 76 U LLSO 176.5 196.1 i1 555 " 31±7 L3 132.14. " (Hg) (Hg) 3214. " 611. 58 593 566 538 244 352 " 591± 225 571 360 300 300 300 300 /0 (CC!;,) Li.22 " 595 585 180 14.60 " lI 586 1±80 1±20 (Hg) 391 iSo 14.80 14.1 381 (CC1L4.) 61 (Hg) 61 26 2( CC 11±) 1431± (cc 114.) 19 9 147 2070 I1L, OL/.) (Hg) 65 55 232 000 (Hg) 63 114.2 " 16 17 202.6 68 75 U 121± " 11±2 38 385(CC1,.) 00 (Hg) 98 " 96 (1) 37 38 39 (2 (3) 70.b 70.L F, tJ L.6 70.L 70.3 L2 )43 LL7 L8 L9 50 51 52 5'3 35-1 2 5 A-i A-i F' 70.9 Vertical 70.6 70.5 70.3 70.5 ,, 70.6 !Ll (L) B B Pr F! B 'F C-2 C-2 C-2 C-2 F' 70.3 70.3 70.6 Fr F, C-2 'F F) 70.8 70.8 F, Fr F, p Ft 70J 26.0* 11.10 25. 5* F, 70. L 'F F1 I, C C C C 25. 5* 10.05 25.0* 25.5* 3.95 26.0* 25.5* 5.95 7.70 9.90 12.50 2.60 3.80 25.0* 25.5* 26,0* ,.00 25.5* 25.0* 10.05 C 70.Lt 70.L (6 9.25 5.85 6.00 7.35 0.70 F) 70.6 70.5 70.5 B (5) 5.75 25. 5* 18.5 6.55 - 6.70 7.35 16.5 17.5 18.0 7.35 * indicates photocell and light 1/20-Inch apart. All other' readings with photocell and light 1/8-Inch apart. 6 70.5 Horizontal 7 70.6 8 9 70.3 70.3 10 11 70.14 12 13 1!4. 70Ji 70.5 70.6 70.6 'F F! 1, tl 'F F' 'F 15 16 70.)4 'I 70.LL F, 17 18 19 70.2. 20 21 22 23 2L. 25 26 27 28 29 30 70.5 70.5 70.5 70.8 70.9 70.9 70.9 70.9 70.9 70.8 70.6 70J 70JL 'F C C C C C F) F) F) F) O 0 o IF F) F, F) 'F 0 F? B F, F' 'F F, PT F, B B B B B B 'F F) F, 'F 6.30 5.)4.O 7.05 5.35 6.65 L.90 5.90 6.55 5.75 5.1.5 7.35 6.10 6.25 5.35 5.00 10.70 11.25 12.25 12.85 11.55 12.20 11.10 7.L5 1.0 iB.o 17.5 18.0 18.5 18.5 18.5 1.0 i8.o 18.5 lu.O iO.o 18.5 18.0 iB.o 18.0 (1) 35-1 (7) 217.8 2 2.9 . 3 276.5 251.9 27L.8 S 6 7 e 9 10 11 12 13 114 15 16 17 19 20 21 22 23 2 25 26 27 28 29 30 31 32 33 3L 35 36 37 38 39 23L!.8 200.3 261.5 196,7 2!8.1 227.9 278.7 267.5 260.5 261.0 265.7 29).7 256,0 232.5 161.9 156.0 175.8 161.7 120.9 123.5 116.3 352.5 297.6 333,0 333,9 369.9 332.0 359.1 297.9 367.0 297.8 332.7 263J 2L6.3 195.8 22.5 50-i 2 3 5 6 7 8 177.1 209.L. 189.9 191.8 207.5 232.9 201.9 199.5 (9) 300 300 300 300 300 300 300 300 300 300 (10) 398 (CC H 666 L23 t1 U 53 (Hg) H 66 ci H 'I 91 H 39 H 20 tt 2L.0 U 22W U I, L3 2LQ hh 180 210 58 20 2L.0 2h0 71i 76 70 73 L8o L20 U H U U U L2 :300 LJ U 300 L2 U 137 153 U 187 150 120 120 90 203 83 102 113 125 90 90 90 90 120 300 303 300 300 300 300 2L0 2Lo '1 U H H H ft 'I 98 ft 89 73 H 61L U H 325 (CC 1 L) L.56 686 ft If 63 (Hg) I, 102 132 iW 162 'I VI 'V 71 H 73 TV L6 I, 5Li. IT 58 69 L; .0 62 63 59 65 39 VT H 'I It 'I H if It 'I H ft IT IT U TV 'V -'C, 'I U 150 73 20 38 37 H 172 53 61 L2 U 180 130 I, L5 (Hg) 7 La i6o H 627 390 U 360 300 21W 16 3 I., I, L 20 365 (CC1) U VT 101 111 I, TV 113 121 129 TI 1 L0 TI 65 78 Q 93 75 70 'I 'I 'I Vt 'V ft VT 'I 59 Vt 52 H L38 (cclL) 9 57° 815 66 (Hg) 9L US 122 129 N0 N ' 0O N f\) $- I.- i-. i- '.D a'J1---'i r\i .- 0 P- N I-. 0 .0 - 0 'O (J\ .n::- LJ N j.) ') Li ' \ji .' - C)0'O".0J . . I till -. r p- Q..Q . I I-. I-a I I-S p. __ p. I- C) C) C) 0 C) 00 C) C C) I.-.- I- .. f. I.- I- I- J\J1 0 J\.fl\j LJ1Y 0 0 I- - nn CDO* YC:-- cxCTcO OCJc I- I.-.. I.- co-i () N 0 0 1111111111 I S Cl Cl Cl Cl Cl Cl Cl Cl :::3 0 0 0 N I - I-. - - o'.o (0X)'O-J 0'0'JThJ - 0O . . . I . I 0') G'JJ 0 N'D 0000 '- NO c'.DO 0 QiiO'0 O-J0rr 0'f\) N-Jf--J 0 CD0'0'- CO TJO\JLO 0 0O\j-O\j-O 0x roO 0\.Q \J0 0 0\jyO-\y . - I-. 111111 I Itt flfO\JQ 0 0 - on 0' - -J -J -J -J -J - -J -J -J - - -J -I -J -J -J -J -J - -J -J - -J -J -J -J - -J -J - -J -0000000000oo - -J - - -J -J -J - - 00000000000000OOQ 0000000000000000000QO OJ 0' N N0'. NNNN \ON r\.) Oj-3 1) (7) (8) 210.9 228.2 260.7 2)40 (10) (9) 176 (Hg) 1 L8 193 207 224. 156 165 172 2L0 300 300 300 2L0 83 177 6L 6LL 21)4.2 300 300 67 70 66 66 196.2 214.0 3):. 20 222. 5 2)40 60 21 250.5 2)4.0 96 135 9 10 11 12 13 1L 15 16 17 18 19 22 23 2)4. 25 26 27 28 29 30 265.L 282.8 125.7 l)L9.9 177.7 198.8 2145.7 265.0 238.9 257.7 238.9 260.7 222.9 29!L.5 23)4.6 2)4.0 255 214.0 210 210 180 180 150 150 120 180 120 66 63 i)4.8 158 177 108 215 228 75 89 iii 120 33 298.8 266.7 291.7 90 1)4.7 3)4. 169 . L, 2)4.0 85 123 135 31 32 36 37 38 39 14.1 LL L6 L.9 50 51 52 239 L 198.0 261.6 1)4.0.5 2)40 283 117 214.0 1)4.5 160 191 261.L 259.2 232.2 252.8 172.5 167.5 200.1 218.9 201.7 22L.0 1L0.5 235.6 2714.6 1L7.)4 55 56 57 259.14 5)4. .58 59 133 2L0 180 180 150 120 120 120 197.5 218.8 2L8.5 232.2 53 90 221.8 103.9 iSo 180 150 150 180 i8o 86 181 " 1.1 6)4 95 ' H 125 1.32 1)4.1 153 165 1714. It tt " " H 179 77 89 106 123 136 86 116 128 158 (Hg) ft ft ft ft t1 ft ft ft H ft if ft ft ft it ft ft ft ft H ft ft It ft ft ft ft ft 215 181 ft 214.6 2014. ft 2'7l 218 ft 231 113 133 165 192 229 253 280 311 102 168 150 180 180 214.0 206 228 " 2)48 102 ' 151 200 106 10 L 1L1 131 iSo 188 150 212 120 120 90 163 179 250 285 326 122 180 i 00 202 233 259 117 ft ft it ft ft H ft ft Ii H ft ft '7 ft ft 'I if ft ft (1) 39 L10 Li t2 IL3 (2) (3) 71.0 Horizontal 71.0 70.9 70.5 70.5 ft 70.LL 15 I6 17 L8 1t9 50 51 52 53 70.6 70.6 70.7 'I 70.7 70.3 V8rtical H 70. 70. 3 70.. 58 59 60 70.6 70.7 70.8 70.8 61 70.9 62 63 6L 65 66 67 68 69 70 D 0 0 C-2 C-2 C-2 C-2 C-2 C-2 C-2 0 0 70 . 1 70.3 70.3 55 56 57 (L) 7o.L 70.8 70.6 70.5 70.6 70.7 70.3 70.7 70.5 ft 0 0 ID ft ft 9.95 12.85 15.35 16.80 18.35 20.25 6.70 11.00 15 55 6.85 9.20 12. 25 C-2 11.60 C-i C-i " " 18.85 8.10 0 0 c-i ft 16.55 13.85 16.35 13.30 20.90 7.85 0 C-2 C-2 " ( 6 ) 101 C--i C-i C-i 9.LLO 5.70 6.75 7.90 9.10 9.75 10.95 3.70 L.L:.0 73 70.L. 70.L 70.L 70. 3 E 10. L0 7L. 70.Li. E 75 70. 5 12.15 :E 71 72 S-I 2 3 5 6 7 8 9 10 11 12 13 70.3 70.3 E " " Vertical A 70 . 70.5 70.6 70.7 70.7 70.8 70.9 71.0 70.9 70.b. 70.3 A " I' Horizontal A A A A A A A A A A A 6.15 9.20 1. 30 7.55 6.35 . 25 3.LLO 10.65 11.35 13.30 15.90 18,55 12.00 1i.77 17.05 8.90 100 100 100 100 - 100 - 100 * 1) (7) 62 63 6t.. 65 66 67 68 69 155 (Hg) 179 171.5 202.2 229.5 206.2 230.3 180 180 180 180 180 150 150 1L3.1 1 20 61 170.2 120 120 71 156.6 lLtl.9 70 21L3.2 71 2)i0.3 270.2 72 2 3 6 7 8 9 10 11 12 13 1 LL 15 16 17 L8 0 70 131.3 139.7 161.0 165.5 i6h.8 106.9 171.1 1480 . 20 360 360 t8o flSc L0 2J0 2L0 90.8 115.3 2.3 2L LLL) 75. 2 106.3 20 22 L8o L8o 360 1LO.0 135.5 157.3 i3L.8 90.5. 25 26 27 136.2 113.0 28 29 30 31 109.9 150.5 92.0 32 180.8 106.5 33 9 L. 6 ft VT 'V 't 1 'I 1 ft I 'I 'V (Hg) 11.7.7 1OL.9 1 23. 1 ft It 51 iih.3 ft L 80 2)L0 2i0 300 300 300 1 20 LLBO 600 'I 1 iL 160 260 I? 308 359 155 190 166 83 'V I' 'V it Vt ft 119 132 151 151 66 76 l i1; '76 70 97 120 I ) I 1L5 165 195 'V I' I, 3L LLL. 69 37 ft 1? fT I1 I' It 'I ft 'I I' I' I' Vt 'I I, r II 68 90 Vt ILl 162 187 92 106 'I 'I 'I tt 'I VI U 'I L. 1 'V 71 II 50 Vt 'V 'V 205 'V 105 'V 103 87 (Hg) I' 26 (Hg) 'I Vt 65 6L 'I 'I ft 56 (Hg) 5.6 56 'I I' TV 28 ft It I' 52 L. 20 Vt ft 120 120 )20 I' 1.02 133 (Hg) 156 TI 92 ,' 205 it IT LLSO 29 21 168 165 71.9 82.7 1oL..9 5 1)41 TV )i0l.3 31L9,S S-i Vt 190 223 30.3 7L1.. ft 91 106 123 90 90 90 90 90 73 75 (10) (9) iSo 60 61 (8) 151 119 91 139 I ,, I, I' ft 'I 22 30 38 35 39 72 58 31 Vt It I, 'I 'I 'I 'I 'I I, (1) (2) (3) 2)i. 70.3 Horizontal 'I 70.3 70.t. U 70.2 H 70.i 70. 70.3 I, 70.b. I, 70,3 70. ?n. 25 s-lL 15 16 17 16 19 20 21 22 2? 26 27 28 29 30 31 32 33 W-1 2 3 U 6 7 8 9 6.35 B B B 7.1.0 B B B B H 7..,.7 70..: C-2 U U 70.L. 70.?. 70.2 70.0 72...' 71.. 71 U 0-2 67. 10 1? A 17.70 t .-t l.j. A 6. L,O U A H A 9.5 H U A A 'I H H A A A A A A 12 A 13 1i. 15 A 70.7 70 7 .90 C-2 H .0 70 6.60 7,65 0-2 H H (6)103 JO 70. 70., 7t,7 (5) A U H S () A A 7,6E 7,G5 7.75 0.75 ..0J 9.25 6.95 0.05 9.05 615 .9O 9.60 ..20 6,13 100 100 100 100 100 100 100 100 100 100 200 200 100 100 100 (11) L"ixing time, iiin 0.0 2.0 5.0 8.0 10.0 15.0 22.0 27.0 30.0 60.0 95.0 120.0 160.0 195.0 20-A 0.0 0.5 2.5 10.0 22.5 27.0 37.0 50.0 71.0 35-A 0.0 1.0 3.0 6.0 10.0 12.0 Light Intensity,% 100.0 38.0 35.0 :t!. 0 36.5 : g 36.0 36.0 37.0 .35.0 3.5 31H S 100.0 33.0 22.0 21.5 22.0 22.0 22.0 22.0 21,0 100.0 29.0 22.0 1( .5 1 L). 5 13.5 i3.5 63.0 79.0 13.5 18.5 18.5 13.5 13.5 0.0 100.0 39.0 L.8.o 50-A 1.0 3.0 6.5 12.0 16.0 25.0 26. 30.0 141 .0 147.0 57.0 6L.0 314.0 21.0 20.0 20.0 20.0 20.0 19.5 19.5 15.5 18.5 18.5 18.0 * I'-' C . . i p . ,. . P 0 p ID . 4 0 ' F-' F-' F-' p F-' p p i p p U) I . p p p 5 F-' I-' F-' 4 F-' Q\ji ID ID ID ID ID p F-' F-' F- I-' - ID Ri 00 (i (Y'-'O p 'Ri -U--a COCDI\.) C 'f\) ID ID ID - I-.' F- I-' p r\i F- C) p c- ID p F5 F- F-' ID '-j r S 0 4 p 5 I F-' I-' * gi 0 0 1 0 p p p - I- 0 CT'\ LD1 p I-' I-' I-' QU, rL 00 --r o-'- Ui Ui 00000 0 -'.O'.O'0 QJ ru -'r\J-c-r\) F-' 0- -1 P p ccoUlo p I ruI-00000: I -. U\i- - -3 Io'-a -. . . Ri Ri Ui Ui r'JLfl - I-' ID S p 0U- fO 0-) O--j O\0Ui Oj-'O 4 ID CD 0- r(UiU)fJ . i-. -' '-0 CY-.3 CY-'j1---'-'-' r cY'\J-r:-- cr'\n Ri ' Jj ) CY' 0 0 OJ C) Y'O- 0" ¼n\ni O-'- C 00 s- s-ç- r'i C ri u ct-a - '-i - - - - '-. -' )- 0 coO QJU QjU) cc::u Ri Ri 0 jt) r\si\Jp p -C O- p Ri ri ri ri '- i- - I-' -: 00 fj I-a F-' I I 0 C3 0-' 0-' CY' O' 0-' 0-' . I p 0 Ui - . - 0 '- ) r\) r., r Ri ID Ri ID IDR) F-' ID f\) f\i$---..) ID -J CY 0-' 0-' n a"- c' c c' con 0 Ui - coO JiOj . I-' F-' p ) LJ I- C) C) - e- 'O - I J )- 0 -O O)-.3 O\rU --- L.-) j) (Y' 0 '-0 Ui \5l J" U,) '-' 'J1 T F-. '1 I- .-j ii.) C) '1 I-' C) I'-'. C) 'p D () . 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N (0'C J ULC\-0 N-N-N----0 -.0 N--Q'.0 )-f\(----OD N-N-N-s-U N-N-N-N-N-r-N-'.O-0 N-N-'-Us-0 N-N-'.0 N-N--'0Uc0U\tOtc\tr\N- I 4'0-0 CON -1 (Q a'0 JCtflJ\c0Q0.zcOc0- N N-(0'-f) N-Ri N-N--N-c I S S S I S ' ' 0 C) C) C) 0 '- a' 0 I-. - I-. rk) I-' '-0 ) \) O)L) '.1) o)_-3 0' 000 0 I-. S S '-i-' S I'._S '-° U '- 0 S S S S ê- ' S S i-.. S S * S 0 0 0 5 5 5 5 5 5 5 5 5 5 5 S S 5 U. * 0 S --' S 0 r5 i-u ru t r'. Ui 0-) \-fl '-.0 '-0 \.n '.1) i_-s s"J1, p 'I'- I- I- l- F- I-' I- l- IS I-S S o4::-U.) I-. 0-O-j::-N) OUi-'3 CT'Ul S S S S S S S r' N) N.) ft,) N) SN.)-5 N.)5 N) f-u N) N) ru ru ru ru S S -. 5 4tnn. -.CT -'-04:r 0 \4Ui..C-.t--U' it- U' pj r'j- - Ui cc'-0 OJCO'.L) Co'.0 a'.C) ctc:c:.-J 0'-.)--.)---)--.)---.]-.J0--.cY- ru r-'D 0 ct oD4.0-Ui o-pj '- '.0 coN) i--' r N.) \ii. CoCt\JU.) CT' 0 '.0 '.0-,) i a-' i_- e i- i-' 0" - U' ) O'-O"Ji.----) C) N)-f.4t0-.]Ui-..]Ui Cr -i (3' CD i_-' - 0) 0" i- '-0 co'.0 U-i.---. 0 o'-o Cr' '- r U'. Cri(fi. 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