Appendix 3 Troubleshooting

This appendix contains the detailed development for the equations that are presented in Chapter 3. Full understanding of these developments is not required for detailed analysis and troubleshooting of the extrusion process. They are presented here for those who desire a deep understanding of the mathematics involved with the screw rotation analysis. Some of the equations and figures are duplicated in this appendix for clarity. The nomenclature used here is consistent with that used earlier. The reader is directed to Chapter 3 for nomenclature. 

A new topic is now included Chapter 20 about quahty assurance. Part of it could be found before in chapter 19 but now the subject is presented much broadly and independent of Analytical HPLC . Two chapters in the appendix were updated and expanded by Bruno E. Lendi, namely the ones about the instrument test (now chapter 25) and troubleshooting (now chapter 26). Some new sections were created 1.7, comparison of HPLC with capillary electrophoresis 2.11, how to obtain peak capacity 8.7, van Deemter curves and other coherences 11.3, hydrophilic interaction chromatography 17.2, method transfer 18.4, comprehensive two-dimensional HPLC 23.3, fast separations at 1000 bar 23.5, HPLC with superheated water. In addition, many details were improved and numerous references added. 

Extensive lists of possible causes and their solutions can be found in the literature, e.g. in Dolan, Snyder Troubleshooting LC-Systems (see literature in the Appendix). 

Consistent with the theme of thehandbook, this chapter has a practice-oriented focus, with the presentation of select theoretical aspects of CE limited to the basic principles needed for understanding how molecules separate in an applied voltage, and the factors that affect the separation. Appendix 2 provides the reader with a guide to troubleshooting typical problems that may be encountered with CE. 

This appendix follows the instructions in the appendices to Chapters 2 and 6. Although the Aspen Plus simulator is referred to, other process simulators can be used. The three problems in this appendix all employ recycle streams in distillation columns. The procedures shown here to obtain convergence are all forms of stream tearing. Since these are not the only methods that will work, you are encouraged to experiment with other approaches. If problems persist while running the simulator, see Appendix A Aspen Plus Separations Troubleshooting Guide, at the end of the book. 

This appendix follows the instructions in the appendices to Chapters 2 and fi. Although the Aspen Plus simulator is referred to, other process simulators can be used. If difficulties are encountered while running the simulator, see Appendix Aspen Plus Separations Troubleshooting Guide that follows Chapter... 

Appendix A. Aspen Plus Troubleshooting Guide for Separations... 

Appendix 5 Sulphonation plant troubleshooting (source Chemithon)... 

In this section, a troubleshooting problem involving an entire process is presented [2]. It is based on the production of cumene problem presented in Appendix C, Figure C.8. The process flowsheet and stream flow table are included in Appendix C. 

Section C also provides useful information on program limits and thresholds (consult individual THRESHOLD entries in the Index), default logical file numbers of user-requested external files (p. C-lOff), internal details of the NBO direct access (read-write) file (p. C-16ff) and other program control variables or error indices that may be referenced in error messages (cf. Appendix D). Keeping the NBO Manual close at hand and knowing how to troubleshoot with Sections B and C can solve many problems before it becomes necessary to contact nbo chem.wisc.edu for further assistance. 

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