Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Downstream, term

The efficiency of the filter is evaluated in terms of the titer reduction or log reduction value (LRV). The titer reduction is the ratio of the number of microorganisms in the input suspension to the number of organisms in the effluent. Similarly, the LRV is the log Q of this ratio. The ratio of the difference between the numbers of challenge microorganisms recovered upstream and downstream of the test filter to the average total challenge received by the filter... [Pg.140]

Enough space must be available to properly service the flow meter and to install any straight lengths of upstream and downstream pipe recommended by the manufacturer for use with the meter. Close-coupled fittings such as elbows or reducers tend to distort the velocity profile and can cause errors in a manner similar to those introduced by laminar flow. The amount of straight pipe required depends on the flow meter type. For the typical case of an orifice plate, piping requirements are normally Hsted in terms of the P or orifice/pipe bore ratio as shown in Table 1 (1) (see Piping systems). [Pg.55]

The level of technical service support provided for a given product generally tracks in large part where the suppHer considers thek product to be located within the spectmm of commodity to specialty chemicals. Technical service support levels for pure chemicals usually provided in large quantities for specific synthetic or processing needs, eg, ammonia (qv), sulfuric acid (see SuLFURic ACID AND SULFURTRIOXIDe), formaldehyde (qv), oxygen (qv), and so forth, are considerably less than for more complex materials or blends of materials provided for multistep downstream processes. Examples of the latter are many polymers, colorants, flocculants, impact modifiers, associative thickeners, etc. For the former materials, providing specifications of purity and physical properties often comprises the full extent of technical service requked or expected by customers. These materials are termed undifferentiated chemicals (9),... [Pg.377]

Afterburn Control. Afterburn is the term for carbon monoxide burning downstream of the regenerator this causes an increase in temperature upstream of the expander. Temperature sensors in the gas stream cause the brake to energize. This provides sufficient resisting torque to prevent acceleration until the afterburn is brought under control by water or steam injection. [Pg.264]

Product separation for main fractionators is also often called black oil separation. Main fractionators are typically used for such operations as preflash separation, atmospheric crude, gas oil crude, vacuum preflash crude, vacuum crude, visbreaking, coking, and fluid catalytic cracking. In all these services the object is to recover clean, boiling range components from a black multicomponent mixture. But main fractionators are also used in hydrocracker downstream processing. This operation has a clean feed. Nevertheless, whenever you hear the term black oil, understand that what is really meant is main fractionator processing. [Pg.242]

If the pressure Pj downstream of the restriction is less than the critical flow pressure, then the maximum obtainable flow which occurs at critical velocity is a function of P, and P but is unaffected by Pj. If Pj is greater than P , however, then the flow is termed "subcritical," and the rate is a function of P, and Pj. There are thus two equations for sizing PR valves in vapor service, depending on whether the flow is critical or subcritical. [Pg.179]

In considering the flow in a pipe, the differential form of the general energy balance equation 2.54 are used, and the friction term 8F will be written in terms of the energy dissipated per unit mass of fluid for flow through a length d/ of pipe. In the first instance, isothermal flow of an ideal gas is considered and the flowrate is expressed as a function of upstream and downstream pressures. Non-isothermal and adiabatic flow are discussed later. [Pg.159]

Values for are selected and the integral on the left-hand side of Equation (13.52) is evaluated. Downstream, evaluation of the right-hand side proceeds from i = 0 up to some value = where the value of the integral exactly matches the original value on the left-hand side. The streamline has moved from iin to i. The density terms will cancel out here and elsewhere in this example. [Pg.501]

In terms of downstream processes, the flow-rates, compositions, and so on, dictate the size and number of each unit operation for example, while a batch distillation may be used to separate a single feed into a number of different product streams, a continuous distillation train would in general require N columns for N different product streams. The fact that a high degree of modeling is used in the design of each MPI, results in the generally held belief that continuous processes... [Pg.315]

In terms of shear stress levels in the developed flow field, the maximum stress [131] occurs at an axial distance between 6 and 7 nozzle diameters downstream and is given by ... [Pg.156]

Such sentinel workflow uses a prediction to select compounds for a more expensive screen that can confirm predicted hazards (liabilities, such as toxicity). It is, provably, the best workflow in contexts where a low prevalence of the hazard is anticipated, and where there is a backstop means further downstream (e.g., preclinical toxicity testing) for detecting hazards before humans are exposed. This workflow then allows the compounds predicted as safe to bypass the expensive hazards screen, without unacceptable risk, and can add significant value in terms of external screening costs or avoiding use of what may be a bottleneck resource. [Pg.268]


See other pages where Downstream, term is mentioned: [Pg.130]    [Pg.180]    [Pg.93]    [Pg.233]    [Pg.582]    [Pg.648]    [Pg.1962]    [Pg.1972]    [Pg.2057]    [Pg.252]    [Pg.501]    [Pg.214]    [Pg.911]    [Pg.62]    [Pg.390]    [Pg.395]    [Pg.474]    [Pg.89]    [Pg.90]    [Pg.159]    [Pg.308]    [Pg.1159]    [Pg.1187]    [Pg.1240]    [Pg.596]    [Pg.61]    [Pg.156]    [Pg.153]    [Pg.311]    [Pg.184]    [Pg.179]    [Pg.181]    [Pg.181]    [Pg.181]    [Pg.155]    [Pg.328]    [Pg.14]    [Pg.260]    [Pg.345]   
See also in sourсe #XX -- [ Pg.1514 ]




SEARCH



© 2024 chempedia.info