Abstract: Disclosed is a method of producing an expanded tobacco material. According to the method, a tobacco material (TM) is fed into a pressure vessel (11), followed by pressurizing the interior of the pressure vessel (11) with a carbon dioxide gas to a predetermined impregnation pressure. Then, a liquid carbon dioxide (21) is supplied from above the tobacco material (TM) into the pressure vessel through a sintered metal plate (13), etc., while maintaining the impregnation pressure, thereby saturating the interior of the pressure vessel (11) with a carbon dioxide gas generated by vaporization of the supplied liquid carbon dioxide, and cooling the tobacco material by the latent heat of vaporization of the liquid carbon dioxide, so as to impregnate the tobacco material with carbon dioxide. The tobacco material impregnated with carbon dioxide is brought into contact with a hot gaseous stream within a gaseous stream dryer so as to expand the tobacco material.

Abstract: A rotary valve apparatus comprises a rotor housing having an inlet and an outlet, a rotor rotatably fitted in the rotor housing, a plurality of pockets arranged at regular intervals in the circumferential direction on the outer peripheral surface of the rotor and adapted to be connected successively to the inlet and the outlet of the rotor housing as the rotor rotates, two communication ports arranged in separate regions extending from the inlet to the outlet of the rotor housing and from the outlet to the inlet, respectively, with respect to the rotating direction of the rotor, and pressure equalizing pipes for connecting one communication port in one region with the corresponding communication port in the other region. As the rotor rotates, the pockets moving from the inlet toward the outlet and the pockets moving from the outlet toward the inlet are subjected to two cycles of pressure equalization by means of one and the same equalizing pipe.

Abstract: Steam or high-temperature gas containing steam flows through a gas-flow drying pipe. Tobacco is fed from a feed port into the high-temperature gas flowing through the gas-flow drying pipe, and heated and expanded while it flows together with the gas. Steam or water is injected into the high-temperature gas flow from injection nozzles at the positions downstream from the feed port to change the gas temperature. Thereby, the heat quantity given to the tobacco from the high-temperature gas is controlled to prevent the tobacco quality from degrading.

Abstract: An expanding apparatus supplies an expanding agent to an impregnating vessel, and continuously supplies and discharges a material, e.g., a tobacco material to and from the impregnating vessel through a valve while pressure-increasing or pressure-decreasing the material, thereby continuously expanding the material. The expanding agent supplied to the impregnating vessel, the valve, and the like is recovered and, air, an impurity gas, or the like mixed in it is removed. Thereafter the expanding agent is pressure-increased to a high pressure and supplied to the impregnating vessel and the valve again.

Abstract: An expanding apparatus continuously expands a material, e.g., a tobacco material and supplies gaseous carbon dioxide as an expanding agent to an impregnating vessel by an expanding agent supply to maintain a predetermined impregnating pressure. The material is continuously supplied to the impregnating vessel by a material supply while increasing the pressure of the material. The material is continuously discharged from the impregnating vessel by a material discharge while decreasing the pressure of the material. The expanding agent supply has a heat exchanger to perform heat exchange between carbon dioxide to be supplied to the impregnating vessel and a coolant, thereby cooling carbon dioxide. The state of carbon dioxide to be supplied to the impregnating vessel is controlled in accordance with the temperature or the like of the tobacco material discharged from the impregnating vessel, so that carbon dioxide is effectively impregnated and no dry ice is formed in the material discharge or the like.

Abstract: An expanding apparatus of this invention includes a preparatory vessel that is supplied with material of agricultural origin, for example, tobacco material. The tobacco material in the preparatory vessel is supplied to an impregnation vessel through a convey pipe. Carbon dioxide having an impregnation pressure is supplied to the impregnation vessel so as to fill the same. A booster mechanism is associated with the convey pipe to increase the pressure of carbon dioxide around the tobacco material to a pressure substantially equal to the impregnation pressure in the impregnation vessel when the tobacco material is supplied from the preparatory vessel to the impregnation vessel. The tobacco material impregnated in the impregnation vessel is discharged to a blow pipe through a delivery pipe and is expanded by means of a heating medium generated in the blow pipe.