Basis design

Before a chemical process design can be properly embarked on, a certain body of information must be agreed upon by all concerned persons, in addition to the obvious what is to be made and what it is to be made from. Distinctions may be drawn between plant expansions and wholly independent ones, so-called grassroots types. The needed data can be classified into specific design data and basic design data, for which separate check lists will be described. Specific design data include [Pg.12]

Required products their compositions, amounts, purities, toxicities, temperatures, pressures, and monetary values. [Pg.12]

Available raw materials their compositions, amounts, toxicities, temperatures, pressures, monetary values, and aU pertinent p%sical properties unless they are standard and can be established from correlations. This information about properties applies also to products of item 1. [Pg.12]

Daily and seasonal variations of any data of items 1 and 2 and subsequent items of these lists. [Pg.12]

AU available laboratory and pUot plant data on reaction and phase equUibrium behaviors, catalyst degradation, and life and corrosion of equipment [Pg.12]

Other correlations based partially on theoretical considerations but made to fit existing data also exist (71—75). A number of researchers have also attempted to separate from a by measuring the latter, sometimes in terms of the wetted area (76—78). Finally, a number of correlations for the mass transfer coefficient itself exist. These ate based on a mote fundamental theory of mass transfer in packed columns (79—82). Although certain predictions were verified by experimental evidence, these models often cannot serve as design basis because the equations contain the interfacial area as an independent variable. [Pg.37]

An important part of hazard analysis and risk assessment is the identification of the scenario, or design basis by which hazards result in accidents. Hazards are constandy present in any chemical faciUty. It is the scenario, or sequence of initiating and propagating events, which makes the hazard result in an accident. Many accidents have been the result of an improper identification of the scenario. [Pg.475]

Dual-beUows assembhes, ie, universal-type expansion joints, are particularly vulnerable to squirm, and can experience elastic squirm at one-fourth the pressure of an individual bellows. When large amounts of offset are encountered, as is often the design basis, a pinwheel effect occurs because of unbalanced pressure forces. This effect tends to rotate the center-spool pipe which may lead to bellows mpture. Eor this reason the center spool should always be stabilized by hinges or tie-rod lugs to prevent such rotation. [Pg.66]

API 617 recognizes the need for the compressor thrust design to take into account peripheral factors such as the coupling. Gear couplings can transmit thrust to the compressor because of tooth friction. The standard uses an arbitrary friction coefficient of, 25, which can be a design basis. Flexible element couplings transmit less thrust because of the lower flex ing element axial stiffness. [Pg.200]

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. [Pg.445]

LUCKETT, F. J., Engineering Design Basis for Plastics Products, HMSO, London (1981) Macdermott, c. p., Selecting Thermoplastics for Engineering Applications, Marcel Dekker, New York and Basel (1984)... [Pg.204]

For the above problem, develop a design basis for a settling chamber as an alternative. [Pg.595]

The following information has been extracted from the design basis for an actual wastewater treatment plant ... [Pg.597]

Conventional Flare System - The majority of pressure relief valve discharges which must be routed to a closed system are manifolded into a conventional blowdown drum and flare system. The blowdown drum serves to separate liquid and vapor so that the vapor portion can be safely flared, and the separated liquid is pumped to appropriate disposal facilities. The blowdown drum may be of the condensible or noncondensible type, according to the characteristics of the streams entering the system. Selection criteria, as well as the design basis for each type of blowdown drum, are detailed later in this volume. The design of flares, including seal drums and other means of flashback protection, is described later. [Pg.207]

The design basis for condensible blowdown drums is as follows ... [Pg.234]

Another example of an unsteady state condensible blowdown system is the design for a phenol condensible blowdown tank. A blowdown tank is used in phenol treating plants to handle streams containing phenol and heavy hydrocarbons (lubricating oil stocks). The blowdown tank is illustrated in Figure 4. The design basis is as rollows ... [Pg.237]

The design basis is the most important eonsideration when determining the size of a biologieal reaetor. Other pertinent faetors are the final produet, the mieroorganism used, its growth rate and oxygen requirement, the produet eoneentration (e.g., expressed in mg/L broth for proteins or 100 mg/L for organie aeids), and the type of produet (intereellular or extraeellular). [Pg.855]

A primary objective of any safety program is to maintain or reduce the level of risk in the process. The design basis, especially inherently safer features that are built into the installation, must be documented. Management of change programs must preserve and keep the base record current and protect against elimination of inherently safer features. For identical substitution, the level of risk in the process is... [Pg.85]

During the facilities design scoping and development prior to completion of the design basis to focus on equipment and configuration (refer to Sections 4.3 and 4.4). [Pg.118]

Seismic design basis for the reactor vessel (including attachments, pressure boundary, and CRD and internals). [Pg.231]

Seismic design basis for the main coolant loop piping and pumps, and for typical category I piping, e.g., the auxiliary feedwater line. [Pg.231]

The analyses of system failures which could challenge the containment or lead to the release of radioactivity form the licensing process. The design basis analyses are deterministic, and degraded core accidents are not considered. PSA determines the probabilities of the numerous sequences that could lead to core degradation and how the core behaves. [Pg.309]

PSAs calculate that accidents more severe than those postulated in the design basis are the principal risk contributors. This indicates that safety designed with a specific goal is successful. [Pg.378]

The DPSE found an acceptably low risk that was dominated by releases during normal operation. The mean risk of the station was estimated to be 9E6 Sv/y to the individual at ihe sue boundary and 7E4 person-Sv/yr to the surrounding population to a distance of 100 km. The consequences of events beyond the design basis were not calculated but their frequency was predic(cd to be 4E-6 /rcactor-y which is acceptably low. The mean economic risk was estimated to be about 10 M /reactor-yr. [Pg.406]

The Pickering A Risk Assessment (PARA) (Ontario Hydro, 1995) is also a level 3 PSA for 1 of the 4 units at Pickering. A difference between PARA and DPSE is that sequences beyond the design basis were modeled using the MAAP-CANDU codes with best estimate assumptions. Other parts of the analysis used licensing-type conservative assumptions. [Pg.406]

The Pickering risk is estimated to be 2E-4 Sv/y to an individual at the site boundary and about 4L-.i person-Sv/y to the surrounding population. Both of which are less than DPSE in spite of age of station, the higher demographics, and the inclusion of beyond design basis events. The mean site economic risk was estimated to be 1.5 M /reactor-y,... [Pg.407]

S. Evaluate the acid relief neutralization system in HE alkylation units to ensure its adequacy tor neutralizing design basis relief valve discharges and unit ventings... [Pg.440]

Design basis. Particles in suspension will settle when the upward flow velocity of the fluid, Mli, is less than the settling rate of the particles, R. i.e. [Pg.83]

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