Abstract: A method for manufacturing a water-absorbent resin includes a cleaning step of cleaning the inside of a heat exchanger that is connected to a vessel holding an aqueous gel-like polymer as a precursor of the water-absorbent resin and is configured to cool a gas containing the polymer generated in the vessel. The heat exchanger, and includes: a plurality of pipes that have an elongated path through which the gas passes, in which the gas is cooled due to heat dissipation during passage through the paths; a chamber that is arranged above the plurality of pipes and is in communication with openings at upper ends of the plurality of pipes; and a cleaner that sprays a cleaning liquid in the chamber. The cleaning step includes at least cleaning the inside of the chamber by spraying the cleaning liquid from the cleaner in the chamber.

Abstract: Provided is a flexible container that can be easily opened. Provided is a flexible container for holding contents that includes an outer bag, an inner bag, a first binding member, and a lid. The outer bag includes a bottom surface portion in which a lower opening is formed. The inner bag is a tubular inner bag that is housed in the outer bag, configured to be filled with contents, and includes a discharge port portion. The discharge port portion forms a discharge path for discharging the contents and extends to a lower side of the bottom surface portion via the lower opening. The first binding member is tied around the discharge port portion to close the discharge path. The lid is attached to an outer side of the bottom surface portion to close the lower opening and cover the discharge port portion. The discharge port portion is narrowed to close the discharge path. The first binding member is tied around the discharge port portion to maintain a state in which the discharge port portion is narrowed.