D type hydrapulper increase hydrapulper capacity by improving bale submergence. The large bales (typically of OCC and mixed waste furnishes) tend to float and spin in a round tub pulper, taking excessive time to wet out and submerge. The D tub design increase the turbulence in the tub, causing the bale to submerge rapidly. Its bowed D wall disrupts the circular flow pattern of a round tub, displacing the vortex and creating a strong hydraulic nip to submerge the bale.