“On the Residence Time Distribution of Particles in a Rotary Dryer with no Air Flow” had been already reported by authors. In this paper, both effects of the falling time of particles and the rotational speed of a rotary dryer were considered in addition to the previous report.
The following theoretical equation was obtained.
T_j=L/NS_dd_j′(n/j) [1/(1+N_nt_j′/60j)] (1+0.033G_a^1/3)(no air flow)
When taking account of air flow, the following theoretical equation was derived by analizing the effect of air flow in addition to the foregoing effects.
T_j=L/NS_dd_j′(n/j) [1/(1+N_nt_j′/60j)] ±1/1-30/4R_e^3/2(ρ_a/ρ_m)S_d^-1G₁^-1+0.033G_a^1/3 (air flow)
It was verified that the experimental values by pulse response method coincided fairly well with the calculated results.

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Photo-sedimentation measurement is classified into the following four methods; (1) photo-scanning method, (2) thin beam photoextinction method, (3) broad beam photoextinction method and (4) photoprogressing method. For comparing these four methods, we tentatively constructed the appratuses and measured the particle size distribution of phosphors. The results obtained are as follows;
With the exception of the method (3), results obtained were in good agreement with each other, and these results also agreed with those obtained by the sedimentation balance method and the microscopic examination. The time required for the measuring was shortest in the method (1) and longest in the method (2). The measured distribution curves were approximately represented by a Rosin-Rammler distribution function. Also, in the method (2), a calculation formula was introduced to obtain the particle size distribution from the sedimentation curve.
Finally, a method was established for calculating the particle size distribution with the electric computer from the sedimentation curves of the Hitachi Photo-Scanning Particle Size Analyser, and we applied this method to a routine control of the powder process for manufacturing television tubes.

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