Manual intervention

The nature of batch operations (unsteady-state), frequently involving manual intervention, creates significant issues pertaining to the design of control systems, design of operating procedures, and the interaction between the... 

In general, the advantages of using an automated method may be comparable to those of SA refinement in X-ray crystallography [68], where many of the operations necessary to refine a structure can be done automatically and the remaining manual interventions are easier because the SA refinement usually results in a more easily interpreted electron density map. Automated methods are usually used in combination with manual assignment. However, fully automated assignment of the NOEs is possible (see Eig. 7) [69]. 

Does this require the installation of alarm, trip, or both, i.e. to what externt is manual intervention expected ... 

The definition of an automatic burner is A burner where, when starting from the completely shut-down condition, the start-gas flame is established and the main gas safety shut-off valves are activated without manual intervention. This means that a burner is only automatic if it is ignited by means of a remote interlock (e.g. thermostat, timeswitch, etc.) closing. A burner is not automatic if it has a pilot burner that remains ignited in the off condition. Nor is a burner strictly automatic if a start button needs to be pushed, even though the controls may comply with all requirements for automatic burners. 

British Standards exist for automatic burners, i.e. those requiring no manual intervention to be ignited. The Standard is ... 

The amount of process plant that can be defined accurately as automatic is relatively small, and manual intervention is often involved at some stage. The relevant design criteria are therefore often IM/12 or IM/18. In practice, fully automatic burner controllers tested and certified by British Gas are available that comply with the requirements of BS 5885. Although these have features which may not be applicable to non-automatic plant, it may be more appropriate to use such a controller, particularly as its safety is well proven. It may also be less expensive than buying and installing separate timers, relays, etc. For some processes (for example, those that do not need and cannot tolerate a long purge) such controllers may not be appropriate. 

Advances in autosampler technology have encouraged the development of fully automated SPE procedures that require minimal manual intervention. Automated... 

Critical Alarms, Operator Supervision, and Manual Intervention of Process Control. Continuously during operations and emergencies. None ... 

A patented water injection system has been devised for extinguishing oil and gas well fires in case of a blowout. The "Blowout Suppression System" (BOSS) consist of finely atomized water injected to the fluid stream of a gas and oil mixture before it exits a release point. The added water lowers the flame temperature and flame velocities thereby reducing the flame stability. In the case where the flame cannot be completely dissipated, the fire intensity is noticeably deceased, preserving structural integrity and allowing manual intervention activities. A precaution in the use of such a device is that, if a gas release fire is suppressed but the flow is not immediately isolated, a gas cloud may develop and exploded that would be more destructive that the pre-existing fire condition. 

While more manual intervention is required, a less costly version of the ATS 4 exists and is called the Linomat application system which has the following limitations Band length, volume applied, number of bands, etc. must all be programmed manually, the syringe must be manually rinsed numerous times before applying a second sample, and it operates at a slower speed than the ATS 4. A photo of the Linomat system is shown in Fig. 13.10. 

One spare electrochemical cell stack is installed in the primary anolyte circuit. Manual intervention is required to connect the spare cell stack and disconnect a faulty cell stack. Five spare cell stacks are kept in storage, allowing replacement of all primary or secondary electrochemical cell stacks (but not both at once) in the case of common-mode failure, e.g., severe blockage. The inventory of spare cell stacks was not deemed necessary to cover common-mode failure of both primary and polishing (secondary) electrochemical cells, because their anolyte circuits are separate and the catholyte circuit is much less likely to be the source of failure (AEA, 2001a). 

Solubility screens using LC/MS detection do not require an ultra-pure sample of the test compound due to the selective detection of the mass spectrometer. Mass spectrometric detection offers high selectivity and low detection limits, which eliminates the need to develop complex chromatographic methods. The LC/MS-based solubility screen surpasses the traditional HPLC/UV-based equilibrium solubility assay with increased throughput, minimal manual intervention, and high sensitivity and selectivity. 

Since control rooms are normally constantly manned, it is considered unlikely that a fire could progress undetected to a hazardous size. Fixed fire protection systems, whether manually or automatically activated, are seldom installed in control rooms of processing facilities, mainly due to the fact that they are normally constantly manned. As such, it is considered unlikely that any fire that does occur would progress undetected to a size that cannot be extinguished by manual intervention (fire extinguishers, hose reel, etc.). 

An early warning HSSD smoke detection system can be used to detect incipient stage fires and allow manual intervention prior to significant equipment damage. Hence, fire suppression may not be required. 

Fig. 19. Two-roll mill showing (a) cross-sectional view of rolls, rolling bank and nip and (b) plan view of rolls and convective effect of manual intervention [129]...

Environmental monitoring is more critical for products that are asepti-cally processed (intensive monitoring) than for products that are processed and then terminally sterilized (normal monitoring). As manual interventions during operation increase and as the potential for personnel contact with the product increases, the number of sampling points increases. 

Preventive measures either take automatic remedial action or allow for manual intervention to prevent the conditions for uncontrolled reaction being achieved. They include the use of sensors, trips, alarms, control systems, and other safety features. These measures require a.thorough understanding of the safe operating envelope within which the process must be maintained.. . ... 

Where systems incorporating manual intervention are used, they have the advantage that they can be flexible and allow operator judgement to be applied. However, their reliability may be open to question as they are dependent upon a number of factors, including complexity of the task, system design, time available for response and operator training. Further information on this is given in references 7 and 8. 

Controls, alarms, and interlocks. The performance of the controls, alarms, and interlocks that were developed in the IQ must be observed and assessed, and the results must be documented during a simulated production ran. For controls that do not function during routine operation, a manual intervention may be used. 

---