Design considerations startup

S.3.3.4 Design of Startup Curves Based on Thermal Considerations... 

Design of Startup Procedures with Both Thermal and Stability Considerations... 

Consideration of the cash-flow stages in Fig. 9-10 shows the factors that can affecd the (EMIP) and (IRP). if the reqiiired capital investment is increased, it is necessary to increase the rate of income after startup for the (EMIP) to remain the same. In order to have the (EMIP) small, it is necessary to keep the research and development, design, and construction stages short. 

Induction motor electrical considerations. When motor starting is desired, the startup torque requirements generally dietate the motor design. The eleetrie eunent inrush at startup is signifieant. The plant eleetrieal grid must be analyzed for eompatibility. 

If casing limitations are fixed by user-supplied relief valves, this information should be conveyed to keep the vendor from rating the compressors on other data. Evaluations can be more of a problem if the same design basis isn t universal with all vendors. Startup and shutdown consideration influence various components, shaft end seals, seal system pressures, and even thrust bearings in some instances. The use of an alternate startup gas, or the desire to operate a gas compressor on air to aid in plant piping dryout should be covered. 

A primary focus in process design is to produce designs that have good overall operability characteristics, as determined by safety and environmental considerations, low product variability, low operating costs, and ease of startup/shutdown. The process design and control system... 

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. 

The productivity of a well depends on the surface of salt available to the injected water. Productivity in a new well is very low, but as the cavity grows it increases to the design rate. In opening a new field, it takes some time to reach full production. This is an important consideration in the startup of a new brine/chlor-alkali complex. The rate of solution of salt increases when the flow of dissolving fluid is turbulent, but this improvement in rate may be offset by a decrease in the concentration of salt in the finished brine. When a new well is brought on line in an operating field, weak startup brine can go to a mature well for saturation, and startup is more efficient. 

The economizer section is designed in full consideration of operating transients, startup and standby operation, and accident conditions such as loss of feedwater flow and feedwater line break. The structural design of the various parts is adequate to withstand the thermal and pressure loadings from these various conditions, consistent with the appropriate load classifications and design rules in the ASME Code, Section III, see Appendix G. 

Many factors affect the mechanical design of evaporator systems, particularly of the calandrias. The two most important are the temperatures and pressures to which the equipment will be subjected. Not only are the temperatures and pressure during normal operation important, but upset, startup, shutdown, dryout, cycling, pulsating pressure, and safety relief requirements are equally important. Other considerations include external loadings from supports or piping and vibrations transmitted from external sources. Wind loadings and earthquake loads must also be considered. Anticipated life expectancy and future service should be considered. 

Refer to Sections II and III for information on designing tests and for detailed descriptions of common laboratory tests. Considerable skill is required to develop a corrosion test program that adequately defines materials requirements. First, we must identify those conditions that will limit the materials selections. This includes the conditions that will be encountered under nonstandard conditions such as startup, shutdown, and process upsets. In many cases we also need to consider the conditions encountered when the unit is in standby status that is, when the unit is not operating but is being maintained so that it can be put back into operation when it is needed. The best materials selections are made when the full range of these conditions is identified and considered before the test program is started. 

Equipment manufacturers do not know how their products will be used at your facility. Therefore, you cannot rely on the manufacturer to have analyzed and designed guarding, controls, or safe procedures for the equipment. Another issue to take into consideration is if the equipment is produced in a foreign country. It may not meet U.S. requirements and laws. Therefore, you should also involve a safety professional in the purchasing decision, as well as in installation plans and startup [2]. 

When a major capital project involving a change or addition to a process safety covered facility is approved, the pre-startup safety review considerations typically begin. The length of time for design, site preparation, installation, and... 

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