Early Stages Of Design Process Research Articles

Tool Cost Estimating at the Early Stages of Cold Forging Process Design

Identifying the most appropriate sequence of cold forging operations for a new part requires a number of technological and economical evaluations concerning loads, mechanical properties of the forged component, its producibility on the machines as well as costs for equipment and associate tooling. This paper presents a methodology for estimating initial and maintenance costs for cold forging tools. This methodology is for use of planners at the early stages of process design, when the sequence of forging operations and equipment are decided and before details of the tooling system are available.

Minimum reflux calculations for nonideal mixtures using the reversible distillation model

A new approach for calculating minimum flows in simple distillation columns is presented. Unlike most previous work, no assumptions concerning ideal boiling or enthalpy behavior are required. The computation time is low, because neither rigorous simulation runs nor column iteration procedures are involved, and the method is suited for the evaluation of a large number of distillation sequences in terms of energy consumption at early stages of process design. The basic idea is the description of a distillation column under minimum reflux conditions by means of the reversible distillation model, which will be introduced briefly. The new method has been applied successfully to nonideal and azeotropic systems. Several calculations are illustrated with comparisons both to a rigorous and to the Underwood method. It will also be explained and demonstrated that the prediction and determination of tangent pinch points is a logical extension of the reversible distillation model.

Interactions Between Process Design and Process Control

Techniques to consider aspects of process control during the early stages of process design are considered in this paper. A survey of existing theory and its application to process examples is given. Needs for further developments are identified.