摘要:
A method to cook thin chips in a continuous digester vessel including: introducing thin chips having a thickness of no more than 6 mm, into a chip bin; adding white (cooking) liquor to the chip bin or to a chip transport passage extending from the chip bin to an upper inlet of the continuous digester vessel; injecting medium pressure steam or another heated fluid to an upper region of the digester vessel to elevate a cooking temperature of the chips in the vessel to at least 130 degrees Celsius; cooking the chips in the vessel as the chips flow downward through the vessel without substantial extraction or introduction of liquor in the cooking section of the vessel; injecting wash liquid to a lower region of the vessel; extracting at least wash liquid through a wash liquid extraction screen in the lower region of the vessel and above the injection of the wash liquid, and discharging the cooked thin chips from the lower region of the vessel.
摘要:
A pulp cooking system including: a cellulosic material feed system, a pre-hydrolysis reactor vessel and a Kraft cooking reactor vessel. The feed material system includes a steaming chip bin and a high pressure transfer device. The pre-hydrolysis reactor vessel maintains the feed material in a mildly acidic condition and allows hydrolysate to be extracted through screens below a hydrolysis zone in the vessel. A wash zone is below the screens and allows wash liquid to flow through the feed material in a cross-current direction. The wash liquid and hydrolysate removed from the feed material is extracted through the screens. The feed material is maintained in a mildly acidic condition through the pre-hydrolysis reactor vessel until the material enters the Kraft cooking vessel where the feed material is treated with alkaline cooking liquors.
摘要:
A method to cook thin chips in a continuous digester vessel including: introducing thin chips having a thickness of no more than 6 mm, into a chip bin; adding white (cooking) liquor to the chip bin or to a chip transport passage extending from the chip bin to an upper inlet of the continuous digester vessel; injecting medium pressure steam or another heated fluid to an upper region of the digester vessel to elevate a cooking temperature of the chips in the vessel to at least 130 degrees Celsius; cooking the chips in the vessel as the chips flow downward through the vessel without substantial extraction or introduction of liquor in the cooking section of the vessel; injecting wash liquid to a lower region of the vessel; extracting at least wash liquid through a wash liquid extraction screen in the lower region of the vessel and above the injection of the wash liquid, and discharging the cooked thin chips from the lower region of the vessel.
摘要:
A pulp cooking system including: a cellulosic material feed system, a pre-hydrolysis reactor vessel and a Kraft cooking reactor vessel. The feed material system includes a steaming chip bin and a high pressure transfer device. The pre-hydrolysis reactor vessel maintains the feed material in a mildly acidic condition and allows hydrolysate to be extracted through screens below a hydrolysis zone in the vessel. A wash zone is below the screens and allows wash liquid to flow through the feed material in a cross-current direction. The wash liquid and hydrolysate removed from the feed material is extracted through the screens. The feed material is maintained in a mildly acidic condition through the pre-hydrolysis reactor vessel until the material enters the Kraft cooking vessel where the feed material is treated with alkaline cooking liquors.