Startup techniques

More has been written about plant startup than one might imagine. Since considerable troubleshooting is needed during startup the two subjects tend to overlap. Therefore, the reader is encouraged to seek startup techniques also within the troubleshooting chapter. 

Even if the safe working temperature is suitable to handle the flashing liquid, pressuring prior to liquid introduction is still the recommended startup technique. This procedure eliminates the large... 

Columns are frequently operated on total reflux during short (from a few minutes to a few days) feed interruptions. Columns are also frequently started up on total reflux. A total reflvix startup is one of the most powerful, and often one of the least troublesome, startup techniques. 

A total reflux startup is one of the least troublesome startup techniques because... 

Constmction/startup techniques will be a better choice ... 

The question to answer for this pre-startup task is Who needs training for this process and to what level of detail One method to analyze training needs is offered by the Instructional Systems Design (ISD) technical training model. It points to the job task analysis method mentioned previously (Appendix D, ISD Model and Job Task Analysis Techniques) to identify procedure titles as a first step for determining which job positions require specific knowledge and skills. 

Establishing a calibration function with one single broad distributed sample is an alternative to traditional peak postion calibration of SEC systems with a set of narrow distributed standards. An obvious advantage of this technique is time for peak position calibration elution profiles for the set of standards need to be determined for broad standard calibration the elution profile of one sample needs to be determined only. Establishing a linear calibration function with a broad distributed standard includes startup information [M (true), Mn(true)] and an iterative (repeat.. . until) algorithm ... 

While startup and shutdown occur relatively infrequently in large continuous plants, they are inherent in batch plant operation. Most startup and shutdown procedures, whether devised empirically or theoretically, are designed to follow a recipe of actions with no feedback. Thus, if upsets occur, there is often no way to change the startup or shutdown in time to avoid imwanted process exclusions. Procedures are needed that incorporate feedback and adaptive techniques to the problem of plant startup and shutdown. 

All pipe-line work to date has dealt with fluids which are not thixotropic and rheopectic. To an extent this may be justified because the limiting conditions (at startup—for thixotropic materials, and after long times of shear for rheopectic fluids) in pipe flow and some mixing problems are of primary importance. Design for these conditions would be similar to the techniques discussed herein for other fluids. This is not true of problems in heat transfer, however, and inception of work on the laminar flow of thixotropic fluids in round pipes would appear to be in order as a prerequisite to an understanding of such more complex nonisothermal problems. 

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