PURPOSE:To reduce a cost by energy saving such as reduction in a fuel cost of boiler, etc., reusing steam evaporated from a raw material in a rendering cooker of the paddle type as a heat source for a vacuum stirring dryer with disc blades. CONSTITUTION:In a production unit for meal bone meal having a dryer using steam a heat source, the dryer consists of the rendering cooker of the paddle type 1 using steam as a heat source, and the vacuum stirring dryer 10 with disc blades using steam generated from a raw material to be steamed or boiled and dried in the cooker 1, having a heat transfer area larger than that of the cooker 1. Namely, the raw material is predried in the dryer 10, sent to the cooler 1, and boiled or steamed finally. Consequently, cost reduction caused by energy saving such as reduction in a fuel cost of boiler can be conducted.
