Optimum Cycles For Falling Rate Processes
Optimum Cycles For Falling Rate Processes
复制标题
速率下降过程的最佳循环
DOI：
10.1002/cjce.5450590512
复制
发表时间：
1981
影响因子：
2.1
通讯作者：
N. Epstein
中科院分区：
文献类型：
--
作者：
R. Ma;N. Epstein
Graphical procedures are derived for predicting both the maximum production and minimum cost cycles for falling rate processes in which the cleaning time fi, is composed of a constant portion, e,,, and a variable portion, e,,, which is directly proportional to the cumulative throughput P at the time the cleaning is started. The procedures turn out to be similar to those for invariant e,, with 8,, replacing 8, in the graphical construction. here are numerous processes in the chemical T industry in which the production rate intrinsically decreases with time. Examples are batch constant pressure filtrztion"', fixed bed ion exchange'2'and constant temperature difference evaporation with scale f~ rmation'~'. A typical plot of cumulative production P vs. time 0 is shown in Figure l (a). A particular case of such a falling rate curve is one in which P approaches a finite asymptotic value, P", as 0 gets large, Figure l (b). Another particular case is that in which dP/d0 asymptotically approaches a constant value as 0 gets large, ie P vs. 0 approaches linearity as 0+ M, Figure l (c). This case occurs for evaporation when the fouling resistance approaches a finite asymptotic value with time.(Batch filters, in contrast, are limited in their capacities, eg by leaf spacing or frame size.) If the linear asymptote is extrapolated back to P= 0, the point of intersection with the 0-axis occurs at 9= 4
