Process engineering typical problems

In this phase of the process, engineers typically undertake a literature search to determine what others have learned about related problems. They may visit technical Hbraries and study textbooks, journal articles, and manufacturers catalogs. Librarians can be very helpful in locating textbooks and journal references, and most hbraries now have access to computer-aided searching services that are fast and relatively inexpensive. Some libraries also maintain manufacturers catalogs reduced onto microfiche film with a subject index to help in locating already-manufactured components. 

Plots of the properties of various substances as well as tables and charts are extremely useful in solving engineering thermodynamic problems. Two-dimensional representations of processes on P-V, T-S, or H-S diagrams are especially useful in analyzing cyclical processes. The use of the P-V diagram was illustrated earlier. A typical T-S diagram for a Rankine vapor power cycle is depicted in Figure 2-36. 

The testing phase is important in expert system development. The practical applicability of the expert system will largely depend on this phase. Testing expert systems is different from normal software engineering in a number of ways. First, it is difficult to test exhaustively the full code and all possible paths the reasoning process may follow. Secondly, the nature of expert systems poses some typical problems. Due to their heuristic nature the correctness of the results cannot be easily verified. A certain degree of errors may be acceptable and, moreover, an... 

This paper addresses a class of problems typically faced by process engineers and operators the detection of assignable variation causes in retrospective data series corresponding to quality or process variables. The detection of average and/or variance changes is dealt as a classical change-point problem analysis where the two main questions raised are 1) Did a change really occur and 2) When did it occur . 

Some materials show different behaviour because of their varying mineral content, proportions of constituent minerals, environment, process of formation, and subsequent geological history. Some materials have properties which create special engineering difficulties. Some typical problem soils which are diseussed in this section are ... 

Instrumentation technicians should be included to provide historical accounts of maintenance problems and typical failure modes. They are also valuable in the development of practical recommendations. A representative firom process engineering will be able to comment on the current operating and safety issues associated with the control of the process and approve recommendations that will effect the operations of the unit. For projects that involve the corporate control group, or require approval of the group, a representative should be involved in the HAZOP. Their knowledge of corporate standards such as the use of by-passes on Emergency Shut Down devices or... 

Chemical reaction engineering problems associated with environmental systems are nijmerous. Design of gas cleaning absorption processes, waste water treatment facilities, low-emission combustion processes, and catalytic mufflers are typical problems. 

In spite of different procedures and design tools, we sometimes come across some typical design requirements that are not covered by any known procedure. Some imderstanding of basic mathematics and fundamental process engineering can solve a large number of problems without much difficulty. For example, a volume calculation of a horizontal vessel requires simple integration, volume calculation of an inclined vessel using Simpson s rule, etc. 

Conversion of acetaldehyde is typically more than 90% and the selectivity to acetic acid is higher than 95%. Stainless steel must be used in constmcting the plant. This is an estabHshed process and most of the engineering is weU-understood. The problems that exist are related to more extensively automating control of the system, notably at start-up and shutdown, although even these matters have been largely solved. This route is the most rehable of acetic acid processes. 

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