Parallel filter

In an HT system, either the star is not grounded or it is a delta-connected system and hence the third harmonic is mostly absent, while the content of the. second harmonic nuiy be too small to be of any significance. For this purpose, where harmonic analysis is not possible, or for a new installation where the content of harmonies is not known, it is common practice to use a series reactor of 6% of the reactive value of the capacitors installed. This will suppress most of the harmonics by making the circuit inductive, up to almost the fourth harmonic, as derived subsequently. Where, however, second harmonics are significant, the circuit may be tuned for just below the second harmonic. To arrive at a more accurate choice of filters, it is better to conduct a harmonic analysis of the system through a harmonic analyser and ascertain the actual harmonic quantities and their magnitudes present in the system, and provide a correct series or parallel filter-circuits for each harmonic. 

APOPO uses a polyester fiber wad for their rats to smell so we ran a parallel adsorption filter configuration (Fig. 8.3) and let the rats smell both the MEDDS and the APOPO filter. Figure 8.3 is a picture of the parallel filter system. 

In order to remove very fine particulate, flue gas leaving the spray tower is distributed to a bank of parallel filtering modules. Within each module, the flue gas first accelerates (compresses) and then decelerates (expands). This action causes water to condense from the flue gas. The water uniformly washes the module s walls. More importantly, water condenses on the fine particulate and acid mist (mostly H2SO4 from condensation of SO3 in the saturated flue gas) present in the flue gas, increasing both their size and mass. Some agglomeration also takes place. 

Dyna Sand Filter. A filter that avoids batch backwashing for cleaning, the Dyna Sand Filter is available from Parkson Corporation. The bed is continuously cleaned and regenerated by recycling solids internally through an air-lift pipe and a sand washer. Thus a constant pressure drop is maintained across the bed, and the need for parallel filters to allow continued on-stream operation, as with conventional designs, is avoided. 

A deep bed system that avoids hetch backwashing to clean the filter is lhe Dyan Sand" filler. The bed design is continuously claimed and regenerated by the internal recycling of solids from the bottom of the bed to the top through an air-lift pipe and a sand washer. This filter allows a constant pressure drop across the bed and avoids the need for a parallel filter to allow backwashing. 

In terms of production, it is very similar to formant synthesis with regard to the source and vowels. It differs in that all sounds are generated by an all-pole filter, whereas parallel filters are common in formant synthesis. 

There is a basic trade-off between parallel- and swept-filter spectrum analyzers. The parallel-filter analyzer is fast but has limited resolution and is expensive. The swept-filter analyzer can be cheaper and have higher resolution, but the measurement takes longer (especially at high resolution). Furthermore, since the swept-filter analyzer does not observe all frequencies simultaneously, it cannot be used to analyze transient events. 

Another kind of analyzer has been developed which offers the best features of parallel- and swept-filter spectrum analyzers. So-called dynamic signal analyzers use analog-to-digital conversion followed by frequency-to-time-domain transformation, usually using hard-wired computational machines, to mimic the function of a parallel-filter analyzer with hundreds of filters, and yet are cost-competitive with swept-filter analyzers. In addition, dynamic spectrum analyzers are capable of measuring amplitude and phase accurately these are basically time domain instruments, and their function will be discussed in Section 3.1.4. 

A simplified schematic of the APLC power circuitry is given in Fig. 10.174. The DC bus (Vac) is the energy storage device that supplies the power required for voltage compensation and current injection. The parallel filter serves two purposes. First, the IGBTs in this portion of the APLC keep the DC link capacitor... 

Figure 25-5 Light from a lamp or from the sun consists of electromagnetic waves that vibrate in all directions perpendicular to the direction of travel. Polarizing filters absorb all waves except those that vibrate in a single plane. All of this plane-polarized light passed by the first polarizing filter is also passed by the second, parallel filter. The third polarizing filter, with a plane of polarization at right angles to the first, absorbs the polarized light completely.

Filtration can be applied in all stages of the process in a central filter in the polymer melt line, or at the end of the line, in the spinning assembly. Central filters are common in large-scale melt-spinning processes, for example, staple fiber production. Two parallel filters may be used to enable filter deaning without interruption... 

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