The Study Of New Process And Equipment Of APMP Pulping

A new poplar APMP pulping process and the main process conditions were studied, and the effect on pulp of all kinds of factors in the new process was analyzed. Wood chips were grinded to wood thread in the refiner after washing, and the wood thread was infused in the admixture of NaOH and H2O2, and then refined to pulp. This process may shorten the pulping flow, increase the quality of pulp, decrease the energy consume, and reduce the produce cost. The clearance of grind, the consistence of wood chips, and the velocity of feeding are the effect factor of the first refining. The smaller grind clearance, the more small wood thread; the more high wood chips consistency, the more uniform wood thread and the more high energy consumption; the more rapid feed, the more stable running of refiner. The effect on the pulp intension of all kinds of factors in the new process condition was analyzed. The dosage of NaOH, the size of wood thread, and the intensity of refining are the main factors effecting on the APMP pulping. With the increasing of the dosage of NaOH, the intension of the pulp will increase, but the scope of increasing will decrease. In this experiment, there are three kind wood threads, and it can get the best intention using the smallest wood thread. Refining is the main effect on the intension of pulp. With the increasing of the refining, the intension will increase. The dosage of H2O2 is the main effecting factor of bleaching in APMP pulping. With the increasing of the dosage of H2O2, the brightness of pulp will increase, and to one point the scope of increasing will decrease. The dosage of NaOH also effects on the bleaching. When the charge of NaOH is the same as H2O2, we can get a better effect of bleaching. At the total chemical charge of 6% H2O2,6% NaOH, the following pulp properties could be obtained: tensile index of 31.02N*m/g, burst index of 1.428 Kpa*m2/g,tear index of 3.62 mN*m2/g ,as well as brightness of 81%ISO. After comparing the pulp made by the process and the equipment of andritz from Yueyang paper mill, we can conclude that the new process is simple, and it can fulfill the need of APMP pulping. A new disc refiner was used,and the theory of the MSD and high consistency refiner were analyzed. The partial feed high consistency disc refiner gets over the shortcoming of common disc refiner, and it doesn't need large feed thrust. Easy feed and smooth exceed, low energy consumption, running stably, which make APMP pulping equipment succeed in china.