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A design correlation is presented for the prediction of steady state product size distributions resulting from a continuous crystal­lizer, based upon a single experimental determination. This has been accomplished by the definition of a new parameter called the "degree of crystallization," which has been related to the experimental nuclea­tion and growth rates in a salting-out crystallizer. The correlation resulted from the detection of variations in the suspension density of the mother liquor which has previously been assumed constant in cer­tain power law models. The degree of crystallization has also been described in terms of dimensionless number, length and area moments which characterize a mathematical model to predict transient size distributions resulting from system upsets in residence time. Included in this unsteady-state model is a unique phase space solution among the moments which has been confirmed by a digital com­puter solution. Computer simulation shows that the assumption of con­stant suspension density leads to an oscillatory behavior of the number, length and area moments. However, simulations in which the assumption was relaxed to permit variations in suspension density were characterized by a smooth self-regulatory operation. Separate studies conducted in a batch crystallizer of special design validates the assumption of McCabe's ΔL law in this work.

Velocity, temperature and concentration profiles were derived for non-Newtonian laminar flow of a reacting species in a tubular reactor. The equation of motion based on a temperature dependent power-law fluid model and the energy equation with internal heat generation caused by a first order chemical reaction were coupled and solved simultaneously using numerical methods to yield the profiles. The assumptions made in this study were: constant physical properties of the fluid (density, thermal conductivity and heat capacity). fully developed flow, wall temperature and negligible diffusion. Compartmentalized calculations resulted in velocity, temperature and reactant concentration profiles for both the axial and radial directions. The pressure gradient along the reactor was determined from the above equations and the continuity principle. These results should be useful in flow reactor design. The pressure gradients, velocities, temperatures and reactant concentrations are interrelated. Due to the temperature-dependent rheological behavior of the fluid; the axial pressure gradient varied with the temperature in the system. The radial temperature distribution distorted the downstream velocity profiles significantly from the entering profile. The radial temperature profile exhibited a peak located between the reactor wall and centerline. This maximum temperature was explained in terms of the internal heat generation and the relatively low thermal conductivity of the fluid. The extent of chemical reaction depends on the temperature and residence time of the fluid in the reactor. Consequently, the conversion near the reactor centerline was lessened by short residence times and that close to the wall was greater due to longer residence times. The wall temperature had an important effect on the reactant concentration profiles. With a low wall temperature, the reaction near the wall was retarded. Two reactant concentration peaks were observed in contrast to a single

Abstract A complete carbon black pilot plant was employed in this study. Carbon laden gas was produced in a fur­nace and introduced into the outer pipe of a heat ex­changer. Air, at the same time, was introduced into the inner pipe of the heat exchanger cocurrently with the carbon laden gas. Thus, heat, with temperature dif­ference as driving force, would transfer from the car­bon laden gas to the air stream. The temperatures along the two streams were measured by iron-constantan ther­mal couples and recorded by a multi-reading temperature recorder. Air supply and fuel (C3H8) supply were intro­duced into the furnace with such rates that about 3oi of combustion would be achieved. The flue gas from the heat exchanger was piped to a collecting system where most of the carbon particles were removed and the gas was released to atmosphere. With the temperature data and the fuel and air flow rate, plus the thermal property data for the gases involved (obtained from some publications), the dimensionless groups such as Reynolds number, Nusselt number and Prandtl number were calculated and correlated to an equation of the Dittus-Boelter form. Due to heat lost to the ambient and carbon particles deposited on the pipe wall, the heat transfer rate for this system was approximately equal to 1/14 of that of a pure gas system without any significant deposit and heat loss. Because of the characteristics of this particular experiment, the result may only be recommended to apply on systems that close to this one. In other words, the generality of the obtained equation is re­stricted by the characteristics of the system employed.

Cold traps have been used extensively for controlling oxygen concentration in sodium systems. Cold traps utilize the positive temperature dependence of the solubility of sodium monoxide in sodium and the resultant precipitation of sodium monoxide at low sodium temperatures. Sodium monoxide precipitation is here assumed to be heterogeneous because of the strong effect of surface area on the precipitation rate shown in previous packless cold trap experiments. Growth of crystals from a super-saturated solution is said to proceed according to the equation where dm/dt is the rate of mass accumulation on the crystal, k is an over-all mass transfer coefficient including a diffusion step and a precipitation step, A is the crystal surface area, C is the bulk solute concentration and Ce is the equilibrium concentration at the temperature of the crystal. A packless cold trap of simple geometry and operating with a temperature gradient was used in this study. In the presence of the temperature gradient, the effective precipitation surface area was a function of the oxygen concentration in the sodium entering the cold trap. An equation describing the change in oxygen concentration with time was derived by performing a mass balance around the system using equation 1 and by accounting for the change in effective surface area with changing oxygen concentration. Eleven cold trapping runs were performed in which concentration was measured as a function of time. Tests were performed at various flow rates, initial oxygen concentrations and final oxygen concentrations. In general, the theoretical model fit the data quite well. Values of the mass transfer coefficients were calculated and were found to be a function of both temperature and flow rate. The dependence on sodium flow rate was proportional to Reynolds number to the 0.6 power. Variation of the mass transfer coefficient with flow rate implied that the precipitation process was diffusion controlled. An Arrhen

Cover title. For piano. "Entered according to Act of Congress in year 1875" -- Cover. Music copyright statement dated 1865; publishers' advertisement on page [2] dated 1884. Publishers' advertisements "Eight standard and pupular funeral marches!" on page [2] and "Garfield's funeral march!" on page [6] with facsimile woodcut image of Garfield's hearse signed: M&H. Plate number: 1482=3., No. 14 of 59 in box 2: Lincoln related sheet music, 1856-1942.