水节点变化对制浆造纸理论最小清水用量的影响

The Effect of Changes of Water Pinch Point on Theoretical Minimum Freshwater Consumptions of Pulping and Papermaking Process

介绍了水节点极限曲线图的作法,并分析了节点图。增大节点处用水单元进出水处的最大浓度,整个水系统的节点向左推移,理论最小清水用量降低,用水单元的水流率升高。降低节点处用水单元进出水处的最大浓度,节点向右推移,清水用量增加。去除节点左侧的用水单元,节点上升,清水用量降低。去除节点右面的用水单元对整个水系统的清水用量没有影响。在总负荷不变的情况下,去除节点处的用水单元,调整前后用水单元的流率,节点变化明显,理论清水用量也随之发生变化。另外还举例说明了水节点图在制浆造纸节水中的一些应用。

In this paper, the way of drawing water pinch diagram is introduced, and the water pinch diagram is analyzed. The theoretical minimum freshwater consumption deceases and the flow rate of the pinch point unit increases as the increase of the consistency of influent and effluent in the pinch point unit, and vice verse. The theoretical freshwater consumption decreases as the pinch point moves toward left side and the freshwater consumption increases when the pinch point shifts to right side. The theoretical freshwater consumption varies with the changes of the flow rate of left or right unit of the pinch point under the circumstance where total load is unchanged and the pinch point unit is removed. In addition, some application examples of water pinch diagram are illustrated.