In a process for preparing water-absorbent resins based on acrylic acid, crude acrylic acid is firstly isolated from the reaction gases from the catalytic gas-phase oxidation of propane, propylene andor acrolein. The system may include a milk inlet system for pressurizing the milk, an air inlet system for pressurizing the air, a mixing area to mix the pressurized milk, the pressurized air, and the steam, and an expansion area to expand the mixture of the pressurized milk, the pressurized air, and the steam. The plurality of third wirings extends in an X direction. A hot watersteam vapor condensate and recycle tube prevents steam build-up in the bottle, and the condensate is led through a drip tube to a collection tray in the base.