Browsing by Author "Turner, KS"

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    The composition of cement hydrating at 60 deg C from synchrotron radiation
    (Australian X-ray Analytical Association, 2002-07-01) Auld, J; Turner, KS; Thorogood, GJ; Ball, CJ; Aldridge, LP; Taylor, JC
    Cement consists of 5 phases C3S, C2S, C3A, C4AF (where C denotes CaO, S denotes SiO2, A denotes AI2O3 and F denotes Fe2O3) and gypsum. When cement hydrates it forms an amorphous calcium silicate hydrate (C-S-H) as well as the crystalline ettringite and calcium hydroxide. The x-ray diffraction pattern of the hydrated cement is difficult to interpret because of its complexity. In addition, the overlapping lines from the remaining cement compounds make it difficult to quantify the amount of the crystalline components present. Using Rietveld analysis we have been able to interpret the patterns obtained from synchrotron x-ray diffraction patterns obtained at the Photon Factory at the Australian National Beamline Facility using BIGDIF. The changes in the composition of the hydrated cement paste were determined as a function of time during hydration at 60 deg C. © 2002 Australian X-ray Analytical Association Inc
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    Separating small particles from liquids with hydro-cyclone, Part I - conclusions and recommendations arising from literature search
    (Australian Atomic Energy Commission, 1959) Cairns, RC; Thurstan, EG; Turner, KS
    A literature search has shown that a two stage hydrocyclone is required to give maximum concentration simultaneously with maximum clarification. For design purposes it is necessary to consider each operation separately. Concentration and clarification efficiencies have been proposed which will enable a choice of the major dimensions of a hydrocyclone to be made for each operation once experimental data are available for various systems. The programme of experimental work required to provide this information as well as information on operation methods is given.
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    Separating small particles from liquids with the hydrocyclone, Part 111 - effects of major operating variables
    (Australian Atomic Energy Commission, 1961-07) Thurstan, EG; Turner, KS
    For cyclone configurations producing flow ratios of 0.1 or less, the concentration efficiency increase as the feed concentration increases and then levels out at a concentration defined as the concentration slightly less than the critical feed concentration and the decrease. Both efficiencies increase logarithmically with flow rate. For a cyclone configuration of feed diameter (Di) = 0.082 in., overflow diameter (Do) = 0.098., and underflow diameter (Du) = 0.037 in., correlations are proposed for the critical feed concentration in terms of the effective density ratio and concentration and clarification efficiencies in terms of the feed concentration, feed flow rate and the Rosin-Rammler-Bennett size distribution constant of the solid. For cyclone configurations producing flow ratios from 0.2 to 0.5, the concentration efficiency is of minor importance. The clarification efficiency was found to be practically independent of concentration and also of flow rate except for materials with large distribution constants. Correlations are proposed for the clarification efficiency for a cyclone configuration of Di = 0.055 in., Do = 0.079 in., Du = 0.058 in. Optimum results may be obtained for a given suspension by choosing suitable flow ratios and hence cyclone configurations for each stage of a multi-stage unit. However, for maximum flexibility underflow throttling would be preferable. The concentration and clarification efficiencies are not greatly affected by the average particle size or size distribution of the solid but the degree of classification obtained is markedly affected by both.
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    Separating small particles from liquids with the hydrocyclone, Part II - effects of major design variables
    (Australian Atomic Energy Commission, 1959-09) Cairns, RC; Thurstan, EG; Turner, KS
    Hydrocyclone feed, overflow and underflow diameters are established for optimum concentration of solid and maximum clarification of liquid using an 11.5 ± 0.5 per cent, by weight suspension of sub-sieve barium sulphate in water. For a hydrocyclone with a nominal diameter (Dc) of 100 millimetres the dimensions for optimum concentration are: Feed diameter (Di) = 0.082 inch (Dc/5) Overflow diameter (Do) = 0.098 inch (Dc/4) Underflow diameter (Du) = 0.037 inch (Dc/11) Vortex finder outside Diameter (VFOD) = 0.197 inch and the dimensions for maximum clarification are: Di = 0.055 inch (Dc/7) Do = 0.079 inch (Dc/5) Du = 0.058 inch (Dc/7) VFOD = 0.197 inch Brief observations are given on the air core and the effects of feed solid concentration and feed solid particle size.
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    Studies of small particle suspensions for L.M.F.R. Part I - fluid flow with suspensions simulating the U-Na systems
    (Australian Atomic Energy Commission, 1957-08) Cairns, RC; Turner, KS
    Velocities of 2.5 to 2.9 feet per second (76 to 88 centimeters per second), are needed to prevent settling of tungsten powder in a 1-in i.d. horizontal pipe from aqueous suspensions containing 6.1 to 7.0 percent by weight of tungsten. In one instance a narrow moving bed was observed at a velocity of 3.8 feet per second for a suspension containing 5.0 percent of tungsten but the formation of a moving bed as not reproducible. Settling has been observed at Reynolds numbers as high as 36,300. The equation of Dallavale, (4), (5) suitably modified predicts settling velocities in a horizontal pipe of the same order as those found experimentally for dense solid, micron-sized particles suspension. For fully suspended flow, the friction factors lie approximately 10 percent above the smooth tube, normal liquid curve. It was not found necessary to consider non-Newtonian relationships to correlate the pressure drop data. At mean Reynolds numbers above approximately 3500 "streamlines" ha been observed in the lower half of the pipe for fully suspended flow. This phenomena is discussed but a full quantitative theoretical explanation is needed toothier with further experimental work.
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    Studies of small particle suspensions for L.M.F.R. Part II fluid flow with suspensions simulating the UBe13-Na system
    (Australian Atomic Energy Commission, 1958-02) Cairns, RC; Turner, KS
    Suspensions of barium sulphate in water at concentrations of up to 16.5% w/w were circulated in a 1-inch loop to simulate the behaviour of the UBe13-Na system for L.M.F.R. In a horizontal pipe the mean velocity for the formation of a moving bed was 1.6 feet per second and the mean velocity for the formation of a stationary bed was 1.4 feet per second. The corresponding mean Reynolds numbers were 15,000 and 13,000 respectively. No agreement as found with Dallavalle's (2) equation previously suggested (1) for calculating the horizontal settling velocities. For fully suspended flow, friction factors were the same as for clean water the density and viscosity terms in the Reynolds number related to the suspension. The validity of the Orr and Dallavalle (5) viscosity equation for such systems was confirmed and non-Newtonian relationships were not required. Striations similar to those previously reported for the tungsen-water system, were observed before and during settling.
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    Studies of small particle suspensions for L.M.F.R. Part V. the effects of concentration, pipe diameter and solid density on the horizontal settling velocity
    (Australian Atomic Energy Commission, 1958-09) Cairns, RC; Turner, KS
    Additional data have been collected for the horizontal settling velocities of small particles suspension. The effect of concentration, pipe diameter and effective density ratio have been determined. In almost all cases a moving bed is formed before a stationary bed. For small concentrations, up to several percent by volume, the effect of concentration is negligible.