[in Japanese]

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Zinc blend concentrate with considerably wide distribution of size was roasted in the fluidized bed. The results of roasting were almost satisfactory and they were analysed with the preceding theory which could explain the several new phenomena recognized in this experiments and made clear the mechanism of roasting in the fluidized bed.

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The pneumatic conveying dryer in pilot plant scale (evaporative capacity 100kg-water/hr) was constructed. This drying system was consisted of gas furnace (600°C gas, 800kg/hr), table feeder, drying column (4″ pipe, 14.47m length), cyclone, bag filter, venturi-scrubber and blower (15m3/min).
The stream of the mixture of gas and wet material was passed through the drying column at high velocity under the barometric pressure.
The new measuring methods were taken to know the gas temperature and the water content of the wet material of this stream at any point of the dryer.
Basic copper sulphate, active carbon, saw dust, (P.V.C.+P.V.Cden), ammonium sulphate, calcium carbonate and pulverized coal were dried and the operating conditions were obtained.
The temperature and humidity of the gas in the drying column were changed along the adiabatic saturation line on the humidity chart, so it could be called that the change of the gas was adiabatic.
The drying time calculated from the equation previously proposed (3) which was based on the assumption that the single fine powder was moving with the gas at the terminal relative velocity in the dryer from the outset of the drying did not coincide with the experimental data.
The effects of the various factors on the drying will be discussed on the report II.

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It is well known that the fluidized catalyst has many points of excellence, but its applications are difficult in certain cases of low rate reactions. The difficulty lies in the following that when the feed gas is supplied at the velocity usually used on the fluidized catalyst, its conversion is low, or that at a velocity of feed which is slow enough to match for the reaction rate, fluidized state can never be attained, or channeling takes place. The fluidized method with mechanical agitation is applicable to these cases.
As one of effective applications, this report shows an illustration regarding the results of direct synthesis of organic silicon compounds by this method. And also the power requirement for agitation is studied, which is necessary for designing the reactor.
The excellent points of this method are as follows.
(1) The catalyst that has a wide range of particle sizes can be used, so that screening is unnecessary.
(2) High reaction rate is obtained, because all of the catalyst surfaces are exposed for the reaction.
(3) The charge and discharge of the catalyst can be accomplished with ease, because the catalyst particles are agitated in layer by layer.
(4) The high heat transfer rate between catalyst and the wall of the reactor enables us to hold uniform temperature distribution in the fluidized bed.
(5) The channeling of gas is prevented by mechanical agitation, and on the other hand the resistance of mechanical agitation is reduced to a great degree by introducing feed gas, and thus both operations go consistently.
(6) Carbon and ashes which may be formed on the surface of the catalyst are removed by mecanical agitation.

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As a fundamental investigation of the design of fluidized bed, experiments have been conducted to study the effects of various factors which determine the conditions of fluidization in fluidized beds, with air and particles such as iron, pyrrhotite, sand, coke, coal, etc. Some empirical correlations using u*=u/um, L*=LC/DP in previous paper are obtained, as
follows:
1. The minimum fluidization velocity
2. The height of fluidized beds
3. The limit of the height of bed in which slugging occurs
From these results, a nomograph and a diagram of fluidization-conditions are presented, by which suitable conditions of fluidization for given particles will be easily determined.
Dp: diameter of pipe; um, Dp, ρS: terminal velocity, diameter and density of particle,
respectively; LC, eC: height and void fraction of static bed, respectively.

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