| 摘要 |
FIELD: pulp industry.SUBSTANCE: pulp cooking system includes: a cellulosic material feed system; a pre-hydrolysis reactor vessel and a Kraft cooking reactor vessel. Feed material system includes: steaming chip bin (10) and high pressure transfer device (12). Pre-hydrolysis reactor vessel maintains feed material in a mildly acidic condition and allows hydrolysate to be extracted through screens (60) below hydrolysis zone (56) in vessel. Wash zone (66) is below screens and allows wash liquid to flow through feed material in a cross-current direction. Wash liquid and hydrolysate removed from feed material is extracted from wash zone through screens (60).EFFECT: feed material is maintained in a mildly acidic condition through pre-hydrolysis reactor vessel until material enters Kraft cooking vessel where feed material is treated with alkaline cooking liquors.27 cl, 2 dwg |
