hydrapulperit

Hydrapulperit are pulping vessels used in the pulp and paper industry, particularly in recycling lines, that employ high-velocity water jets and mechanical agitation to disintegrate paper stock into a pulp slurry. They are designed to repulp shredded or recovered material and assist in separating contaminants so the fibers can be processed further.

Operating principle: Stock is mixed with water in a chamber, and a rotor or jet-system creates high shear and turbulence. The mechanical action breaks down fibers, while the slurry circulates for uniform pulping. The pulp is typically discharged through screens or grills to remove larger contaminants, and finer fibers proceed to downstream washing, screening, or deinking stages. Temperature and consistencies are managed to balance pulping efficiency with fiber preservation.

Configurations and variants: Hydrapulpers come in open or closed configurations and can be oriented horizontally or vertically. Some designs include screens, dispersers, or specialized nozzles to enhance pulping and contaminant removal. They are often integrated with subsequent cleaning, screening, and deinking equipment in a recycling line.

Applications: They are commonly used for repulping mixed paper, old newspapers, and corrugated containers, particularly in deinking and stock preparation processes. Hydrapulpers are chosen for their ability to disrupt bulky material and loosen contaminants prior to further refinement.

Considerations: Key factors include energy consumption, wear on rotors and screens, and potential fiber damage from shear forces. Effective downstream screening, washing, and deinking remain essential to achieve desired pulp quality. Maintenance and safety requirements are important in plant operation.

History and context: Hydrapulpers emerged as a standard component in many recycling mills during the maturation of modern pulp and paper processes and remain in use where rapid pulping of recovered fiber is needed.