Operational objectives

The incineration facilities for processing nuclear power plant wastes should be designed to meet the operational objectives identified in Ref. [4]. The design of facilities for processing other radioactive wastes may assume that the operational objectives identified in Ref. [4] are still valid. 

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Furthermore, for quality and operability objectives the plant does not wish to recycle the AN product stream (top of distillation column), the feed to the distillation column and the feed to the decanter. 

By being independent of the audited activities, the auditor is unaware of the pressures, the excuses, the informal instructions handed down and can examine operations objectively without bias and without fear of reprisals. It is for this reason that it was considered appropriate for the auditor to have no direct responsibility for the work being audited i.e. audits carried out by a manager, supervisor, or foreman of his/her own department or section do not qualify as internal quality audits in ISO 9001 1994. However, they will qualify under ISO 9000 2000. 

Meeting Boiler Plant Operating Objectives with All-Polymer/All-Organics... 

All-organics, to meet boiler plant operating objectives... 

Nobody can ever rightfully claim to hold the absolute truth on survey data interpretation, or to possess the only path for future operational objectives and strategies. Nevertheless, the more experienced water treatment representative will tend to provide a more practical and cost-effective proposal than the new recruit, fresh from the vendor s training school. 

Unfortunately, a lot of the operational objectives for the POSRV described above could not be achieved as economically as with a spring valve the use of soft seats was imperative to obtain all advantages, which limits the use of most POSRVs in high temperatures (typically up to 300°C maximum). There are now POSRVs in the market with metal-to-metal seats, but here tightness, especially after a few operations, decreases much more than with resilient-seated valves and even traditional spring-operated metal-to-metal valves. 

The operating objective for this system is to control the mole fraction of the product B in the liquid product stream at iB,sp = 0.819, in the presence of disturbances in the inlet composition and changes in the production rate. 

We will first concentrate on studying the process dynamics, so let us consider a numerical experiment that consists of starting a dynamic simulation of the process from initial conditions that are slightly perturbed from the nominal, steady-state values of the state variables. Although material holdups are stabilized using the proportional controllers in Equation (4.40), in view of the process-level operating objective stated above, this can be considered an open-loop simulation. 

The concentration of impurities (present in the feed) in the process evolves over a very slow horizon (days or, possibly, weeks). Moreover, the presence of impurities in the feed stream, together with significant material recycling, can lead to the accumulation of impurities in the recycle loop, with detrimental effects on the operation of the process and on its economics (Baldea et al. 2006). Therefore, as was shown in Chapter 4, the control of the impurity levels in the process is an important operational objective, and, according to the analysis presented above, it should be addressed in the slow time scale, using the flow rate of the purge stream, up, as a manipulated input. 

The operational objectives for this process are the stabilization of the reactor holdup and operating temperature, as well as controlling the product stream s temperature and maintaining its purity within the specifications of a downstream... 

Where facilities employ multiple shifts of operators or have rotational leave personnel (such as offshore or at remote foreign locations), it may be prudent to include an operator from each shift or work period, in the review process. It may be realized that the separate shifts or work periods may have different methods to achieve similar operational objectives. 

According to experiences gained from the experimental biomass gasification-power generation plant in Putian and the electricity consumption characteristics of the timber mill, this plant can reach the operation objectives as follows ... 

Here the critical process variables are identified from the selected list of process variables. The model library or process data (if available) are used for this analysis. To perform the sensitivity analysis, the process operational model is simulated through ICAS-MoT. The effect of each process variable on the target product properties is analyzed systematically through open loop simulation. The operational objectives have to be assessed first. If an operational objective is not achieved, then the process variables have to be analyzed. The variables which violate the operational limit and have a major effect on the product quality are considered as the critical process variables. For some of the variables which can not be modeled the sensitivity analysis has to be performed qualitatively through inference from the knowledge base and/or by the use of process data. All the critical process variables need to be monitored and controlled. For some of the critical variables that can not be measured in real time, other correlated properties have to be measured so that all critical variables can be measured and controlled by using the correlations to the measurable variables. 

The operational objective for the fermentation step is to maximise the specific cell growth rate. Open loop simulations (fig. 3) show that the value of the specific growth rate is considerably lower than the maximum specific growth rate throughout the batch... 

Figure 3. Profile of operational objective Figure 4. Critical process variable (pH) 3.5. Interdependency analysis...

Plant Operations Objective To produce the product. a) Plant startup b) Trouble shooting c) Process improvement d) Production e) Plant engineering... 

The first commercial application of the Mobil Methanol-to-Gasoline (MTG) process has now been in operation for over a year and a half in the Gas-to-Gasoline (GTG) plant in New Zealand. The catalyst used in the process and the reaction mechanism impose important design constraints. This paper discusses the approach used for the scale-up and design of the fixed-bed MTG reactor system. Design philosophy and selection of equipment to meet the stipulated process and operating objectives are also reviewed. 

Safety and the satisfaction of production specifications are the two principal operational objectives for a chemical plant. Once these are achieved, the next goal is how to make the operation of the plant more profitable. Given the fact that the conditions which affect the operation of the plant do not remain the same, it is clear that we would like to be able to change the operation of the plant (flow rates, pressures, concentrations, temperatures) in such a way that an economic objective (profit) is always maximized. This task is undertaken by the automatic controllers of the plant and its human operators. 

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