Experimental and theoretical studies have been conducted on the electric field produced by the surface composed of different kinds of materials(copper-polyethylene and copper-nickel systems). Radioactive material, ²⁴¹Am, was utilized in the measurement of the electric potential profile. The experimental data obtained agreed well with the theoretical results for the copper-nickel system, while the experimental error for the copper-polyethylene system increased with the increase in the distance between radiating material and the test surface.
As an alternative method for the measurement of an electric potential profile, insulating oil-bath was used. The experimental results obtained by the second method did not agree with the theoretical results, and a long time was required to obtain the steady state value of the electric potential. It is also confirmed that the deposition of charged aerosol particles was affected by the localized electrostatic field, and the particle charged with positive porality deposited mainly on the nickel surface.

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Experiments on high flow velocity filtration were carried out by a granular moving bed filter for the separation of particulates from a dusty gas. The gas was flowed countercurrently to the gravel stream with the intention of increasing the gas flow velocity in the operation. The effects of the flowability of dust and the flow velocity of the gas on the collection performances were examined. When the dust load on the gravel is low, the collection efficiency is little effected by the flowability of dust because the dominant capture mechanism is inertial deposition. However, the distribution of the dust load captured on the gravel is considerably effected by the flowability of dust.

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The transportation of solids at low fluid velocities has recently begun with the object of reducing the pressure drop and power consumption in a pneumatic conveying system. Therefore, it is important to investigate flow characteristics at low fluid velocities. One of them is the solid particle velocity. Thus, in this paper a basic equation for the velocity ratio of particles to fluid was derived on the basis of the observation of solid flow patterns in Part I for the established flow at low fluid velocities in horizontal pipes. On the other hand, measurements of the solid particle velocity for the flow were conducted by measuring the impulsive force of the solids fluid two phase flow by the use of a ballistic pendulum. The unknown quantities in the equation were determined by analyzing of the experimental data, and an empirical equation was obtained. More than 95% of the values calculated by the equation fall within ±12% of the experimental values.

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