微粒子懸濁液の二流体ノズルによる微粒化

抄録

DL powder, which is called a driftless powder and has a particle size of 10 to 46μm, is being produced in practice by pulverizing and classifying mineral particles such as roseki, talc, limestone and so on. The authors are trying to reutilize the powders less than 10μm, which is a by-product in producing DL powder, by means of a spray drying method.
This paper deals with the flow characteristics and atomization of slurries composed of water, polyvinyl alcohol (PVA) and clays, such as roseki and talc. The conclusions are summarized as follows:
1. PVA, added as a binder for products, effectively dispersed roseki and talc in the slurries. The apparent vicosity of the slurries at 50% mass concentration, showed the lowest value at an about 1% PVA solution.
2. The mass median diameter of slurry droplets could be estimated by Kim-Marshall's equation applicable to Newtonian fluids. In the calculation of the equation, the apparent viscosity of the slurries at the shear rate of 300s^-1 was used in place of the vicosity of Newtonian fluids.
3. The size distribution of droplets approximated to the logarithmic normal distribution and the geometric standard deviation, one of the parameters in the distribution, was connected with the mass median diameter.