Abstract: A sealing structure for a cylindrical body has an O-ring holder in which a planar O-ring that provides a seal in the planar direction and a radial O-ring that provides a seal in the axial line direction of the cylindrical body are incorporated in the crossing direction provided at both end parts of the cylindrical body; a pressing means for pressing the O-ring holder in the axial line direction of the cylindrical body via a pressing lid; the O-ring holder is pressed against a tube sheet of the fluid chamber via the pressing lid by the pressing means to press the planar O-ring onto the tube sheet, whereby a fluid tight seal is provided between the fluid chamber and the outside; and the radial O-ring is pressed onto the outer periphery of the cylindrical body to provide a fluid tight seal between the fluid passage and the fluid chamber.

Abstract: [Problem] To provide a system for recovering carbon dioxide from flue gas, in which a reboiler in a regenerator can be compactly installed, and a method therefor, in facilities where CO2 or the like contained in flue gas is recovered. [Solving Means] To include an absorber 1006 that absorbs CO2 contained in flue gas 1002, a regenerator 1008 that strips CO2 from CO2 absorbent (rich solution) 1007 to regenerate absorbent, internal shells 101 provided at a bottom of the regenerator 1008 with a predetermined interval therebetween, into which regenerated CO2 absorbent is introduced by a feeding unit 102 from a bottom side thereof so that the CO2 absorbent overflows from an upper end of the internal shell thereof toward the bottom of the regenerator, and a reboiler that is inserted into the internal shells 101 in a direction orthogonal to a vertical axis and includes a heat-transfer tube 103 that reboils absorbent.

Abstract: A sealing structure for a cylindrical body has an O-ring holder in which a planar O-ring that provides a seal in the planar direction and a radial O-ring that provides a seal in the axial line direction of the cylindrical body are incorporated in the crossing direction provided at both end parts of the cylindrical body; a pressing means for pressing the O-ring holder in the axial line direction of the cylindrical body via a pressing lid; the O-ring holder is pressed against a tube sheet of the fluid chamber via the pressing lid by the pressing means to press the planar O-ring onto the tube sheet, whereby a fluid tight seal is provided between the fluid chamber and the outside; and the radial O-ring is pressed onto the outer periphery of the cylindrical body to provide a fluid tight seal between the fluid passage and the fluid chamber.

Abstract: [Problem] To provide a system for recovering carbon dioxide from flue gas, in which a reboiler in a regenerator can be compactly installed, and a method therefor, in facilities where CO2 or the like contained in flue gas is recovered. [Solving Means] To include an absorber 1006 that absorbs CO2 contained in flue gas 1002, a regenerator 1008 that strips CO2 from CO2 absorbent (rich solution) 1007 to regenerate absorbent, internal shells 101 provided at a bottom of the regenerator 1008 with a predetermined interval therebetween, into which regenerated CO2 absorbent is introduced by a feeding unit 102 from a bottom side thereof so that the CO2 absorbent overflows from an upper end of the internal shell thereof toward the bottom of the regenerator, and a reboiler that is inserted into the internal shells 101 in a direction orthogonal to a vertical axis and includes a heat-transfer tube 103 that reboils absorbent.