摘要:

AbstractPractically all hydrometallurgical processes involve leaching of solids to dissolve valuable constituents. This usually is followed by a liquid‐solids separation before producing the final product. The liquid‐solids separation step requires careful investigation because:1.Soluble values must be recovered to a very high degree for economic purposes.2.Final liquor volume must be minimized to reduce capital and operating costs of later steps.3.Usually large amounts of gangue solids are associated with the digested pulp requiring care in minimizing wash volumes.4.The colloidal solids are strongly dispersed by retention times and pH conditions in leaching. This necessitates flocculation investigations to achieve desired results.5.Operation must be dependable under severe conditions of pH, abrasion, fast settling solids, temperature, etc. Equipment must have flexibility to allow efficient operation under even abnormal fluctuations.6.An appreciable percentage of initial investment is required for this portion of the plant.The two common liquid‐solids separation methods —countercurrent decantation and filtration with cake washing, are discussed. Investigation and correlation procedures for prediction of full scale results and design requirements are stressed. Emphasis is given to the influence of particle size distribution, temperature, pH, flocculation, repulping, solids concentration, and filter cake perme

ISSN:0008-4034    

DOI:10.1002/cjce.5450370102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450370103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

摘要:

AbstractThe flow characteristics of the two‐phase system —white mineral oil and water—were examined in a horizontal, smooth, one‐inch pipe. Flow conditions were investigated over a range of input oil‐water volume ratios from 0.1 to 10 at thirteen superficial water velocities ranging from 0.116 ft./sec. to 3.55 ft./sec. A theoretical analysis of the laminar flow of two immiscible liquids between wide parallel plates yielded a modified parallel plate friction factor based on the water properties and the superficial water velocity. It was evaluated for a number of input oil‐water volume ratios and plotted against the superficial water velocity. The experimental pressure drop data that were obtained were correlated using a modified Fanning friction factor which was evaluated for the range of input ratios studied and correlated with the superfical water velocity. A flow pattern correlation was obtained for visually observed types of flow—bubble, stratified and mixed—and it was shown that these patterns occurred in laminar, transitional or turbulent conditions of flow. The theoretical analysis for flow between wide parallel plates was adapted to obtain hold‐up relationships, and a plot of the hold‐up ratio HR(the input divided by the in situ oil‐water volume ratio) versus the input oil‐water ratio was constructed. This plot indicated that in the laminar region of flow the hold‐up was not dependent on the superficial water velocity but was only a function of liquid viscosity and input ratio. Experimental results for flow in the pipe conformed with this prediction while indicating that in the turbulent region superficial water v

ISSN:0008-4034    

DOI:10.1002/cjce.5450370104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

摘要:

AbstractInstances are cited in which the pressure gradient in an oil pipe line has been reduced by the injection of water into the pipeline. A general mathematical analysis is presented for two immiscible liquids flowing (1) in two layers between wide parallel plates, and (2) concentrically in a circular pipe. This will form a basis for the further study of oil‐water systems. Equations are derived relating the volumetric flow rates and the viscosities of the liquids with the pressure gradient. The conditions for which minimum pressure gradients and minimum power requirements occur were determined and these minimum values have been compared with known values for a pipeline flowing full with only a single liquid. The factors by which the pressure gradient and power requirement can be reduced are very large. For example, for an oil of viscosity 1,000 cp. flowing concentrically with water, the reduction factor is approximately 500. The pressure gradient reduction factors reported in the literature are compared with those predicted by theory, and conclusions are drawn regarding the position of the water phas

ISSN:0008-4034    

DOI:10.1002/cjce.5450370105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

摘要:

AbstractTabulated numerical data, nut hitherto available, are presented for the number fraction distribution of residence times of particles in fluid which passes through a series of 1, 2, 3, … up to 75 mixing zones in series. For the special case in which the weight of particles varies linearly with time, the weight fraction distributions of residence time are also tabulated. The theory is recapitulated and extended to include the effect of recycl

ISSN:0008-4034    

DOI:10.1002/cjce.5450370106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

摘要:

AbstractThe effects of high field viscosity and of low inter‐facial tension on the terminal velocity of single liquid drops falling through stationary liquid fields were investigated. Drops of tetrachloroethylene, ranging from 0.08 cm. to 1.4 cm. equivalent diameter, were allowed to fall through four different types of field fluids made by the addition of carboxy methyl cellulose, Lytron 890, corn syrup, and glycerine to water. Viscosities varied from 41.3 to 514 centipoises.Low interfacial tension systems were ethylchloroacetate‐water, furfural‐water, and benzyl alcohol‐water with interfacial tensions of 16.43, 5.70, and 4.25 dynes per cm. respectively.For systems of high field viscosity, the usual drag curve appears to be more useful than the correlation proposed by Hu and Kintner. For systems of low interfacial tension (below 20 dynes/cm.) and low field viscosity (of the order of one centipoise) the latter serves to correlate accurately the data of 25 systems.A comparison of the pour technique with the usual nozzle method for the introduction of drops resulted in a terminal velocity difference of less than three percent. Wall proximity corrections were made when ne

ISSN:0008-4034    

DOI:10.1002/cjce.5450370107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

摘要:

AbstractThe best method of noise control is elimination of the noise at its source by modification of the noise producer; in certain cases this may not be possible since the normal functioning of the noisy device would be impaired. Alternatively the source may be enclosed, either completely or partially so as to shield the observer from the source. A third method involves the treatment of surfaces in the room containing the observer and noise source to absorb the noise as it is propagated through the room. Finally the observer, or at least his ears, may be enclosed by a soundproof booth or the wearing of ear defenders.Examples of the successful quietening of pieces of machinery will be discussed, including the couch roll of a paper making machine. A reduction of 15–20 decibels in sound pressure level has been achieved without interference with the paper making qualities of the rol

ISSN:0008-4034    

DOI:10.1002/cjce.5450370108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450370101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1959

数据来源: WILEY