Takeshi Akao

Indirect Heating of Solid Particles

Conductive heat transfer between particles and a wall was studied in continuous operation by horizontal well-stirred cylindrical vessels. An annular particle layer of 0.7 to 12 mm thickness on the wall was formed under the action of centrifugal force from blade rotation. Three sizes of vessels (82–150mm I.D., 450–1000mm L.) and three kindsterials were used in this study.

Solid Fermentation by Air-Solid Fluidized Bed

The disadvantage of static solid culture is its difficulty in controlling the temperature and moisture, thus limits thickness of fermentation layer. An air-solid fluidized bed is characterized as perfect mixing in solid phase and high rate of oxygen supply. We design an air-solid fluidized bed fermentor investigated the enzyme production by cultivating Aspergillus sojae. A 16 1 bench scale fluidized bed type fermentor. Three kg of ground wheat bran passed through mesh sieve was sterilized and charged as substrate. The moisture level reached to 40%. SiX g of seed mold A. sojae was inoculated cultured for 60 h at 33 C. Alkaline proteinase activity peptidase activity were 5 times and 10 times, respectively, for fluidized bed culture in compare to conventional culture. In fluidized bed culture, a little bit thicker hyphae penetrated or invaded into the pore of wheat bran. The cells for fluidized bed culture were smaller than those for submerged culture. In small cell, very large mitochondoria were observed and number of mitochondria per unit volume were roughly twice that of that large cells. The small cells were adapted highly to aerobic condition. Cytochromes of large cells were in reduced form while those of small cells were in oxidized form.