The Use of Sequestrants for the Removal of Calcium Salt Deposits from Stainless Steel Surfaces

abstractcts - 9905152 c。本研究将探讨在中性和碱性环境下使用固溶溶液从不锈钢表面去除钙矿物膜的传质和表面反应的作用。将使用三种类型的实验，范围从实验室到工业规模：(1)批量溶出研究。在这些实验中，通过将粉末颗粒悬浮在溶液中来研究矿物的溶解。从传质的角度来看，这个实验没有很好地表征，但它代表了文献中发现的溶解动力学的标准研究。(2)从旋转圆盘中溶解。在这个实验中，一层钙矿物薄膜将沉积在一个不锈钢圆盘上。通过在清洁溶液中不断旋转圆盘，将薄膜除去。这个实验有一个很好的特征传质率，在整个薄膜表面是均匀的。这将使我们能够在溶解过程中分离出膜形态的表面演变的作用。(3)在紊流管道中溶解。在这里，典型条件下的清洗速率将被量化。

AbstractCTS-9905152C. Grant, NCSUThis research will investigate the role of mass transfer and surface reactions on the removal of calcium mineral films from stainless steel surfaces using sequestrant solutions in neutral and alkaline environments. Three types of experiments will be used, that range from laboratory to industrial scale: (1) Batch dissolution studies. In these experiments the dissolution of the mineral is investigated by suspending powder particles in the solution. This experiment is not well-characterized from a mass transfer point of view, but it represents the standard study of dissolution kinetics found in the literature. (2) Dissolution from a rotating disk. In this experiment a film of calcium mineral will be deposited on a stainless steel disk. The film will be removed by continuously rotating the disk in the cleaning solution. This experiment has a well-characterized mass transfer rate that is uniform over the whole surface of the film. This will allow us to isolate the role of surface evolution of film morphology during the dissolution process. (3) Dissolution in turbulent pipe flow. Here the cleaning rates under typical conditions will be quantified.