General equations for payout calculation are developed, taking into account selling prices, total costs, and production, as regards the time elements. Profit annuity, which means. an annuity of the increase in the company assets for the optimum service life of equipments can be shown by Eq. (17) as a suitable expression for the economic balance.
Investment for all engineering purposes, such as selection of a type of process or equipments, determination on the equipment size, decision for replacement, should be made with a view to attaining the maximum profit annuity with respect to service life thereof and investment as shown in Eqs. (23) and (24).
According to the procedure suggested here, some assumptions can be either eliminated or transformed as you like to suit your circumstances, and any factors you want may be fairly taken into the equations. As an example, general equations are developed on the MAPI assumptions.
For sound investments, it is necessary to get correct interest rates, on which some views differ- ent from the currently prevalent ones are given.
The method presented here may be employed to remove the disadvantages of some of the methods generally in use.

View full abstract

Theoretlcal and experimental studies on discharge coefficient of a small nozzle in centrifugal field were carried out, and its result was employed to determinc angular velocity of liquid which flows between discs of a disc-type centrifuge.
The results obtained were summarized as follows:
(1) The discharge coefficient based on the experimental results is calculated by:
(2) The discharge coefficient in centrifugal field is identical with that in gavitational field concerning the same nozzle.
(3) In the case of high Reynolds number above 3, 000, the discharge coefficient is considered to be nearly constant.
(4) The average angular velocity of liquid which flows between discs through a nozzle with a known discharge coeffiiient is expressed by:
(5) The angular velocity of liquid between discs is considered to be approximately equal to the angular velocity of a bowl, independently of the flow condition, number of revolution of the bowl and distance between the two adjacent discs.

View full abstract

Mixing characteristics of flow reactors were studied, Using irrigated packed towers to make clear dynamic characteristics of reactors, flow mcchanisms of fluid and holding time of fluid in reactors, The method employed in our study was the residence time curve method, the commonest one employed in such a case.
An equation for the residence time curve, with the boundary conditions suitable for these irri- gated packed towers, was analytically derived from the concepts of the mean velocity and the apparent diffusivity, as suggested and used by Danköler³⁾, Gilliland⁵⁾, Danckwerts²⁾, and Yagi¹¹⁾, in the course of studies of flow through tubular reactors, fluibized beds, and multistage agitated tanks.
The results of the residence time curve equation thus obtained were compared with the data derived from the experiments with the irrigated packed towers whose total holdup had been measured. The region in the irrigated packed towers in which our investigations were centered, in connection with the mixing characteristics of the liquid holdup, was where the models of the mean velocity and the apparent diffusivity were reasonably applicable.
Fig. 1, Table 1 and Table 2 show the apparatus and the dimensions of packings and towers used in these experiments. With this apparatus, the total holdup and the residence time curves, from which the values of M (Table 4) were determined by means of Eq. (7), were obtained under various conditions, either with or without gas flow.
The conclusions derived from the experimental data illustrated in Figs. 2, 3, 4, 7, 8, 9 and 10 are as follows:
1) Operating characteristics of liquid hold flowing in a packed tower are specifed by the mean flow velocity, u=L/θ=L/(Q_t/F), and the dimensionless group, M=uL/2E, which represents the mixing characteristics of liquid flow.
2) By Eqs. (12) and (15), the operating holdup without gas flow, H_op, and the apparent diffusivity, E, are respectively well correlated with the mean liquid velocity, u. A simplified method is proposed for estimating the static holdup, H_st, by the use of mean liquid velocity, u, instead of superficial liquid velocity; that is, by means of extraporating observed values of Ht relative to u=0; obtaining excellent results, as shown in Table 3. This is because H_t and u are linear correlation represented by a straight line, as illustrated in Fig. 3.
3) The values of M in the case of irrigated packed towers, as listed in Table 4, are very high as compared with those in other types of flow reactors, indicating that the liquid flow in a packed tower closely resembles the piston flow, the more so, by increasing the length of the packed bed and the mean velocity of liquid and decreasing the diameter of packing.

View full abstract

Vapor-liquid equilibria of CH₃CN-α-picoline mixtures were studied, using materials purified by batch distillation. Their boiling points under 760mmHg and the refractive indices obtained are tabulated in Table I. An Othmer type apparatus with some modifications6) was employed for getting equilibrium boiling data, which are tabulated in Tables III and IV. Figs. 2 and 3 are graphic representations of Table III. The determination of the mixture compositions was made by means of refractive indices at 30°C, for which Fig. 1, a graphic representation of Table II, was employed.

View full abstract

Solubility of chlorine dioxide has been measured at 0, 5, 10, 15, 20, 30 and 40°C.
The apparatus used is shown in Fig. 1. The experimental results are shown in Fig. 2, Fig. 4. The distribution constants of the system are tabulated in Table 1.
The freezing point depression of chlorine dioxide aqueous solution is shown in Fig. 5.
The conclusive correlation is presented by Equation (2). The equilibrium condition of chlo- rine dioxide-hyarate-water is shown in Fig. 6.

View full abstract

Physical properties of two binary systems, isopropyl alcohol-water and isopropyl alcohol-benzene, are determined experimentally. The kinds of physical properties observed are density, refractive index, viscosity and surface tension, whose data are useful for the analysis of binary mixtures. The smoothed data are presented in Table 2 (a). (b) and Figures 1 to 5 (a), (b).
Inspection of the Tables and Figures reveals that there are maximums in the viscosity vs. composition curves as well as in refractive index vs. composition curves, for the system isopropyl alcohol-water and that there exists a minimum in the relation between viscosity and composition for the system isopropyl alcohol-benzene. A small addition of isopropyl alcohol is found to reduce the surface tension of water markedly
Parachor and molar refractions are calculated, using the data obtained as above, and it is confirmed that these quantities are linearly correlated with molar composition, except for the parachor of the system isopropyl alcohol-water. Molar refraction is also confirmed to be independent of temperature within the range of experiments. Furthermore, some discussions are made on the theoretical relations between surface tension or viscosity and composition.

View full abstract

Various gases are known to form a solid hydrate in the presence of liquid water at temperatures above 32°F and most of the constituents of natural gases to form a hydrate. Applying the Hildebrand rule, the relation between pressures and temperatures of methane, ethane, propane, ethylene and acetylene hydrates is presented by the following generalized equation, having constants α and C for each hydrocarbon, to predict the hydrate conditions.
p^-0.1563=αT^-0.1563+C
On the basis of thermodynamic relations, some of which are assumptions, the heat of reaction of the hydrate in different regions is calculated.

View full abstract

Summary: In the range of this experimental study, rheological equation of polyvinylchloride is quite exactly written as D=τⁿ/η. And n and η are approximately reprsented as follows,
n=2.5, 1g₁₀η=22.3-(4.25t+6.91c)/100

View full abstract