Unit Monitoring and Control

The only proper way to monitor the performance of a cat cracker is by periodic material and heat balance surveys on the unit. By carrying out these tests frequently, one can collect, trend, and evaluate the unit operating data. Additionally, meaningful technical service to optimize the unit operation should be based on regular test runs. 

Finally, before the unit can produce one barrel of product, it must circulate catalyst smoothly. One must be familiar with the dynamics of pressure balance and key process controls. 

In the material and heat balance sections, the discussions include  

In the pressure balance section, the significance of the pressure balance in debottlenecking the unit is discussed. Finally, fundamentals of both basic and advanced process controls are presented. 

This chapter presents the entire procedure for performing heat and weight balances. The last section of the chapter discusses the use of the distributed control system and computer in automating the process 

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Unit Monitoring and Control 175 The pressure in the regenerator dome is ... 

To operate the MPI or LPI equipment at stable and reprodncable inspection conditions modern units are equipped with a monitoring and control system called "Quality Assurance Package" (termed QAP). The QAP System is ba.sed on an industrial PC with a bus system and field sensors. It ensures that process parameters important for the reproducability of the MPI or LPI are controlled an held between defined limits by a central computer system. It can be adapted to any old system, as well as integrated into new systems. 

Most sulfonation plants monitor and control operations by computer. Sulfur-buming catalytic SO -generating equipment may require a 1—2 h stabilization period on startup. The unit can be kept in a standby position by maintaining heat to the unit when it is off-line. Liquid SO -based sulfonation plants do not require such a stabilization period and hence are more flexible to operate than sulfur-buming sulfonation plants. 

The chapter on Radioactive chemicals (Chapter 11) has been updated. Considerations of safety in design (Chapter 12) are presented separately from systems of work requirements, i.e. Operating procedures (Chapter 13). Tlie considerations for Marketing and transportation of hazardous chemicals are now addressed in two separate chapters (Chapters 14 and 15). Chemicals and the Environment are now also covered in two chapters (Chapters 16 and 17) to reflect the requirement that the impact of chemicals on the environment should be properly assessed, monitored and controlled. Although a substantial contribution to atmospheric pollution is made by emissions from road vehicles and other means of transport, and this is now strictly legislated for, this topic is outside the scope of this text. Chapter 18 provides useful conversion factors to help with the myriad of units used internationally. 

The contents of the AHSV are continuously recirculated using the agent hydrolysate transfer pump and are returned to the AHSV through a jet mixer. The vessel contents are agitated and maintained at 194°F. The pH is monitored and controlled at all times to eliminate the possibility of agent reformation. Hydrolysate from the AHSV is supplied to the SCWO reactor units in Area 300 through the agent hydrolysate transfer pump. 

Among the most significant features of the ARO unit are its ability to be remotely monitored and controlled, and its ability to automatically call for help, both accomplished through a modem and telephone connection. These features allow for rapid diagnosis and service response. 

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