Downstream Circuit

These porous structures may hinder the transport of solutes away from the membrane downstream surface, causing a local increase of the solute partial pressure and hence a decrease of the driving force (19.1). Eventually, solute condensation may occur if the solutes local partial pressure surmounts its saturation vapour pressure. This problem becomes particularly relevant when dealing with high-boiling aroma compounds [14] and when pressure drop in the downstream circuit increases owing to poor module design. 

X-to-R ratio of generators is high, e.g. between 20 (for LV generators) and 100 (for HV generators). However, the value of armature resistance is of most importance when considering the downstream circuit-breaker fault clearance capabilities. This aspect is described in sub-sections 7.2.7 and 7.2.11. The calculation of current magnitudes may be carried out in several ways depending upon the amount and accuracy of the data available. 

The situation for the secondary circuit is different. The purpose of instantaneous protection is to detect major faults at or near to the secondary terminals and at the downstream switchgear e.g. busbar fault. This protection must also be coordinated with the instantaneous protection settings of downstream circuits e.g. static loads, motors. The settings chosen are much less sensitive to the upstream source characteristics than those of the primary protection, because of the inclusion of the leakage impedance of the transformer in the faulted circuit. 

On the industrial scale, the vacuum pump is shut off once vacuum is established in the downstream circuit and ideally the condensahon unit alone maintains the vacuum. This procedure allows operahng in a more economical way allowing mini-mizahon of energy costs. 

To avoid this situation, some regulators are designed with a built-in over-pressure relief mechanism. Over-pressure relief circuits usually are composed of a spring-opposed diaphragm and valve assembly that vents the downstream piping when the control pressure rises above the set point pressure. 

Control philosophies applied to continuous countercurrent decantation (CCD) thick eners are similar to those used for thickeners in other applications, but have emphasis on maintaining the CCD circuit in balance. It is important to prevent any one of the thickeners from pumping out too fast, otherwise an upstream unit could be stai ved of wash liquor while at the same too much underflow could be placed in a downstream unit too quickly, disrupting the operation of both units as well as reducing the circuit washing efficiency. Several control configurations have Been attempted, and the more successful schemes... 

Fig. 9.2 shows how a simple open circuit gas turbine can be used as a cogeneration plant (a) with a waste heat recuperator (WHR) and (b) with a waste heat boiler (WHB). Since the products from combustion have excess air, supplementary fuel may be burnt downstream of the turbine in the second case. In these illustrations, the overall efficiency of the gas turbine is taken to be quite low ((tjo)cg = ccJf ca 0.25), where the subscript CG indicates that the gas turbine is used as a recuperative cogeneration plant. 

The mere fact that voltage, current, or even both, are at low levels does not guarantee a circuit to be intrinsically safe, even though intrinsically safe circuits do utilize relatively low voltage and current levels. Intrinsically safe systems employ electrical barriers to assure that the system remains intrinsically safe. The barriers limit the voltage and current combinations so as not to present an ignition hazard should a malfunction develop. Typically, devices upstream of barriers are not intrinsically safe and are installed in control rooms or other unclassified locations. All devices and wiring on the downstream side of the barriers are intrinsically safe and can be installed in classified areas. 

Beyond the standpipes, the available delta P across the valve is affected by the pressure drop in other circuits. For the regenerated catalyst slide valve, downstream pressure is affected by ... 

The initial incident involved a pinhole leak on a 6-in. line located 112 feet above grade. The unit might have been shut down at this point, but a decision was made to keep it on line. Efforts to isolate the circuit by closing four block valves failed. The line remained hot and the level in the downstream stripper vessel continued to rise. Several attempts were made to depressure the circuit and free drain all the residual naphtha. At least 15 work orders were issued over a 13-day period and most of these failed to meet the company s own work standards. 

To protect the HPRT outlet casing integrity and mechanical seals from possible downstream back pressure transients a relief valve installed in the HPRT outlet piping circuit should be considered (see Figure C.1). 

Various circuits have been described to measure collection efficiencies based on galvanostatic control of the upstream electrode with the downstream electrode being held at the limiting current for the reaction taking place there. It is also possible to measure N0 by a potentiostatic shielding experiment. For, an irreversible electrode reaction, measurement of N0 in these two different ways will, in principle, give different results if the upstream electrode is not uniformly accessible. 

Anomalies in the power wiring are a common cause of stray magnetic fields in commercial buildings and hospitals. Neutral-to-ground connections downstream of the main bonding connection cause some of the neutral current to return via the ground path. This path is not predictable and results in residual magnetic fields due to mismatch in the supply and return currents to the various electrical circuits in the... 

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