To positively make coating amount different in a radial direction, while suppressing dispersion of coating amounts of catalyst slurry of individual carriers of a monolith type catalyst.
Natural moisture absorbed in a carrier 1 from the atmosphere is removed in advance by applying forced drying treatment by using a hot air supplying device 4, then the carrier is subjected to humidifying treatment as a pretreatment before coating the catalyst slurry. The carrier 1 subjected to the drying treatment in advance has smaller dispersion of the coating amounts of the catalyst slurry of the individual carriers 1 compared to those not subjected to the drying treatment, at the same time, the coating amount increases. By installing a shielding plate 42 with a ventilation hole 43 formed thereon between the carrier 1 and the hot air supplying device 4, drying degree of the carrier 1 in the radial direction is positively made different, and the coating amount of the catalyst slurry is correspondingly varied.
GOCHO TAIJI
Hiromichi Kobayashi
Tomioka Kiyoshi