Fuente: WIPO "industrial hemp" The ultra-low-temperature dewaxing kettle comprises a reaction tank body, a cooling chamber surrounding the reaction tank body is arranged on the outer side wall of the reaction tank body, a liquid adding opening and a liquid outlet are formed in the cooling chamber, an air hole is vertically formed in the upper side of the cooling chamber, an exhaust pipe is connected in the air hole in a sliding mode, and the liquid adding opening and the liquid outlet are formed in the upper side of the cooling chamber. The upper end of the exhaust pipe extends to the upper side of the cooling cavity, the upper end of the exhaust pipe is in threaded connection with a limiting nut, the lower end of the exhaust pipe extends into the cooling cavity and is closed, a through hole communicated with the inner side of the exhaust pipe is formed in the side wall of the lower end of the exhaust pipe, the lower end of the exhaust pipe is connected with a sealing piece, and the sealing piece can seal the air hole. Buoyancy pieces are connected to the lower ends of the sealing pieces.