Ventilator for offset pocket and method of ventilating the same

Abstract

The ventilator is used to ventilate an offset pocket in the drying section of a papermaking machine. The papermaking machine comprises a row of spaced-apart upper drying rolls and a row of spaced-apart lower drying rolls. It also comprises two rows of spaced-apart felt rolls disposed intermediate the upper drying rolls and the lower drying rolls, respectively, and a paper web intermittently carried by two felts entrained over the upper drying rolls and over the lower drying rolls, respectively. The ventilator comprises a ventral face and a dorsal face. The ventral face comprises at least one ventral orifice disposed adjacent to the felt and the dorsal face comprises at least one dorsal orifice disposed adjacent to a combined draw of felt and paper web. In use, the ventral orifice discharges air through the open felt draw such that the air traverses the felt to the other side thereof and into the offset pocket, and wherein the dorsal orifice discharges air in a direction opposite to the direction of travel of the combined draw to create a countercurrent air flow between the ventilator and the felt roll. A method for ventilating an offset pocket is also disclosed. The ventilator and the method for ventilating improve the ventilation of offset pockets.