Vertical pneumatic conveying: An experimental study with particles in the intermediate and turbulent flow regimes

Vertical pneumatic conveying was studied in a 3-inch diameter riser 30 feet in length using solids ranging in particle Reynolds number from 100 to 3500. Particle to gas mass flow ratios varied from 0 to 8 and pipeline conditions extended from dilute flow down into the choking region. Average particle hold-up was determined by means of a series of quick-closing valves and particle slip velocity was often found to be greater than the calculated terminal velocity. The reasons for this are examined. Frictional pressure losses in the riser were also determined and compared with literature data. The phenomenon of choking is considered briefly.     

Towards properly controlled analytical measurement methods

It is of great practical importance to develop simple methods for the automatic detection ofthe controlled state of the analytical method being applied. The key point is to find quantities that greatly affect the quality of the analytical results and that can be easily estimated during the measurement process from the measured data. The signal-to-noise ratio has proved to be such a quantity in gas chromatographic methods. The statistical properties of the estimation of the signal-to-noise ratio from gas chromatographic data have been investigated. The suggested practical method for estimating the signal-to-noise ratio proved to be biased from a mathematical statistical point of view, but the bias is usually not greater than 10%. It has been shown by practical examples that the signal-to-noise ratio affects the quality of the analytical results and it is easy to estimate its value from practical data.     

Deposition of dense isotropic carbon from acetylene in fluidized bed

Pyrolytic carbon was deposited from acetylene in a fluidized bed at 1100°C on alumina microspheres. In case when only argon was used as the diluent gas, density and BAF of the deposit decreased and deposition yield increased with increasing acetylene concentration. Hydrogen sypply suppressed carbon formation and, consequently, caused an increase in density and Lc. BAF was relatively independent of hydrogen concentration. It was found that high density, isotropic carbon can be deposited from acetylene at 1100°C, if an appropriate proportion of hydrogen is added.     

Static and dynamic strain-dependent viscoelastic behavior of black-filled EPDM vulcanizates

The strain dependence of the dynamic mechanical properties of HAF-N330-filled EPDM vulcanizate was studied using a Rheovibron DDV III EP. It is shown that when a dynamic strain is superposed on a static strain, the viscoelastic response of filled rubbers becomes more complex. Under these conditions, dynamic mechanical properties do not correlate with the double strain amplitude. A strain called the “total strain” has been defined in order to interpret the experimental results. It is also shown that the dynamic mechanical properties are displacement velocity dependent, while the comparison is made under identical conditions of strain and frequency. Separability of time and strain effects is observed for the storage modulus, whereas the loss modulus is shown to be a nonseparable function. The elastic and the relaxation components, constituting the mixed function representing the storage modulus are shown to have similar deformation dependence. © 1994 John Wiley & Sons, Inc.     

A new batch solvent-extraction pilot plant

Summary and Conclusions A new improved batch solvent extraction plant and its versatility of design have been described. Data have been given on the cost and initial test operations. The performance of the plant has been tested, and its value as a research tool has been demonstrated by the production of free gossypol and meals low in gossypol for use in research. Simplicity of operation is borne out by the fact that only one operator is needed. A limited number of detail drawings of the plant are available on written request from the Southern Regional Research Laboratory. Presented at the fall meeting, American Oil Chemists’ Society, Nov. 2–4, 1953, in Chicago, Ill. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

The effect of processing conditions upon the nutritional quality of vegetable oils

On the basis of the chemical, physical, and biological criteria used, all of which have been shown to be sensitive indicators of heat damage to oils, it must be concluded that the overall nutritional quality of an oil is not adversely affected by alkali refining, adsorptive decolorizing, or deodorization; that higher temperatures of deodorization (238C) produce oils nutritionally equivalent to those deodorized at lower temperatures (160C); and that the normal processes used in manufacturing edible oils improve the resistance of these oils to heat damage. Presented at the 6th Congress of the International Society for Fat Research, London, 1962.     

Consolidation of sand formation using freon'll gas hydrate

Freon 11 gas hydrate was used to block the pores of four size ranges of sand from 24 mesh to 60 mesh. A 50.8 mm deep bed of sand when thus “frozen” with hydrate could sustain a dfferential water pressure of at least 6895 kPa. A subcooling of about 5 to 6°C below its thermodynamic formation temperature was required to cause the hydrate to form such a plug. Once formed, the hydrate remained stable at temperatures up to its decomposition temperature. The time required for the hydrate crystal to grow to a size large enough to block the pores of the bed was about two hours. The amount of hydrate forming agent required to block the sand pores was found to be approximately that calculated from the ideal composition of the hydrate.