Startup and Operability

All six processes are easily operated once they have been started up and are under control. Time required for startup can vary from one hour or less for reverse osmosis units to four hours for multiple-effect evaporators. Ease of startup is not usually a major consideration because most desalination plants operate continuously with few shutdowns. 

All processes exhibit some degree of complexity based upon the need for controls, chemical addition, pumps, and other components. Reverse osmosis is 

Other factors that affect complexity are site-specific and are not included the the ranking above. 

Seawater Supply Seawater required per unit of water produced varies from 2 for mechanical vapor compression to 3 for reverse osmosis and 8-10 for the other processes. Seawater requirements may dictate more or larger equipment. 

Seawater Quality Evaporating processes are not greatly influenced by seawater quality if operating temperatures and concentrations are properly controlled. Seawater quality significantly affects the complexity and extent of pretreatment required for reverse osmosis. 

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One of the best definitions is by Attilio Bisio (1) The successful startup and operation of a commercial size unit whose design and operating procedures are in part based on experimentation and demonstration at a smaller scale of operation. He also points out that Smith (2) argued in 1968 that the starting point for scaleup studies is the ultimate intended commercial unit. The professional should scaledown from the design parameters and constraints of that commercial unit so that the smaller scale experiments were most useful in reducing the uncertainties of the commercial run. Smith wrote that scaleup from small-scale studies is a misleading concept. 

Any problems in the setup, startup, and operation of the CBMS also were recorded in the course of the field tests. These observations are important to improving the system before it goes into production. The field tests revealed three problems. The protective screens over electronics cooling air inlets and outlets on the CBMS II housing were damaged by operator activities in the vehicles and required reinforcement. The ground probe head, which protrudes outside the vehicle hull, required more power to maintain the correct temperature under colder or wetter weather conditions. Finally the automated mass and frequency calibration procedure was not reliable in the field and required modification. These problems have been corrected and are being incorporated in the LRIP units. 

Full-scale startup and operation, including shutdown and maintenance activities... 

After safety has been built into the process, it must be maintained throughout the remaining life cycle stages of the process, beginning with facility startup and operation. 

Kelly, A., and Engstrom, F. Startup and Operation of the Kauttua 200,000 lbs of Stream per Hour Cogeneration Ahlstrom Circulating Fluidized Bed Combustion, Coal Technol. (Houston), 4th (vol. 5), p. 7 (1981). 

Okes, E. J Javen, J., and Engstrom, F. Startup and Operating Experience at the Kattua 22-MWe Cogeneration Circulating Fluidized Bed Combustion Plant, Proc. Am. Power Conf., Vol. 44, p. 64 (1982). 

Provides continuity by being involved from the very onset of the project through the startup and operation of the facility. 

Startup and operating staff requirements must be determined and schedules prepared for their training and integration to the project team at the right moment. 

Conduct hazards and safety reviews in cooperation with the appropriate personnel and. if required, outside consultants to insure a safe, efficient plant startup and operation. 

Similar detailed design and scale-up considerations were extended to the other sections of the MTG plant and resulted in meeting its startup and operating goals. 

This paper examines the important role simulations have played in the startup and operation of the GTG complex and the follow-on effects which have been achieved. Developed below is a chronological progression of the major uses the simulations have seen over the past 5 years. 

Few column startups are completed without instrument problems. Instrument problems are not unique to startups they also occur during normal operation. Below are some of the most common instrument problems encountered during column startup and operation ... 

There are several definitions of scale-up, the one in a classical scale-up textbook being Scale-up is defined as the successful startup and operation of a commercial size unit whose design and operating procedures are in part based upon experimentation and demonstration at a smaller scale of operation. ... 

Maintenance and engineering Maintenance and engineering will work closely during systems specification, installation, startup and operation to provide maintenance with the technical depth required to maintain aU assets and systems. 

J. P. Meyers, Fundamental Issues in Subzero PEMFC Startup and Operation, presentation at 2005 DOE Workshop on Fuel Cell Operations at Subfreezing Temperatures, February 1-2, 2005, Phoenix, Arizona, http //www.eere.energy. gov/hydrogenandfuelcells/pdfs/03 meyers distribution.pdf... 

After the successful startup and operation of the PCLA 1, there began a long period of explosive development of the FCCU unit designs (22, 23, 24, 25). This period represents an era of advancement in engineering concept and design rarely seen in the industrial world. A summary of FCC unit designs and when they were first launched is included in Table III. 

In spite of precautions taken during the design of evaporator systems, problems do arise during startup and operation. Parameters which cannot always be precisely determined make it nearly impossible to define all the problems during the design stage. These parameters include ... 

Plant data, including tests carried out during commissioning or startup and operational occurrences or accidents. 

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