Regeneration time

Shorter cycle times produce smaller bed sizes. The minimum cycle time is usually dictated by the minimum regeneration time required to heat and cool the bed. Systems of greater than two beds provide some flexibiUty in regeneration time but add to investment costs. 

An additional problem exists in which impurities in the displacer itself complicate separation.54 Also, the displacer itself must be removed from the column, which lengthens regeneration time and can adversely affect throughput. Ironically, while the difficulties involved in identifying displacers and in column regeneration have retarded use of displacement as a preparative method, there has been renewed interest in using displacement chromatography in analytical and semi-preparative applications for enrichment of trace compounds.55 56... 

For vapour detection there are three aspects that are modelled sensitivity, response time, and regeneration. The sensitivity determines at which concentration level the detector will respond. The theoretical detector output (alarm or no alarm) is calculated by comparing the input data (concentration, relative humidity) with empirical detector display outputs, obtained during controlled exposure laboratory experiments. The response time determines how long it takes before the detector actually shows the response and it depends on the concentration level. The regeneration time determines how long it takes, after a positive detection, before the detector can do a new measurement. 

Regeneration time As a gas trapping device, the cryopump must be regenerated after a certain period of operation. Regeneration involves the removal of condensed and adsorbed gases from the cryopanels by heating. The regeneration can be run fully or only partially and mainly differs by the way in which the cryopanels are heated. 

The evolution of the spatially averaged NOx coverage i//NOx (i-e., the amount of the NOx stored in the converter) in the course of the FTP cycle can be seen in Fig. 28. At the test start, the catalyst is fully regenerated. Time intervals with... 

Figure 14 Effects of increasing photocatalytic regeneration time on tlie subsequent photocatalytic oxidation of toluene. (From Ref. 57.)...

The time required to heat, desorb and cool a bed is usually in the range of a few hours to over a day. Because during this long regeneration time the bed is not productively separating, temperature-swing processes are used almost exclusively to remove small concentrations of adsorbates from feeds. Only in such situations can the on-stream time be a significant fraction of the total cycle time of the process. 

Figure 11. Product quality from an adsorber varies as the regeneration time is varied. Feed gas is 20 N2/80 CH. ...

Reservoir Volume (103 km3) Part of total volume (%) Regeneration time... 

The regeneration time is determined by the time in which silt passes from the beginning of the regeneration corridor to the beginning of the oxidation corridor. Purified waste waters self-flow out of settling boxes 22 through pans into dirt settling box 25. Dirt is removed from there as it accumulates. 

Explosive-based terrorism is an eminent threat to a civilized and free society. Accurate and cost-effective explosive sensors are, therefore, essential for combating the terrorist threat. Some of the main performance characteristics for explosive sensors include sensitivity, selectivity, and real-time fast operation. As the vapor pressures of commonly used explosives are extremely small, highly sensitive sensors are essential for detecting trace quantities of explosives. Moreover, the sensors should have high selectivity to have an acceptable rate of false positives. Also, these sensors should have the capability of mass deployment because of the breadth of terrorist threats involving explosives [1], Finally, these sensors should have fast detection and regeneration time for fast operation. Currently available sensors are unable to satisfy these requirements. 

RIfS-measurements with this layer were not possible because such thin layers do not provide a distinctive interference pattern. Even the 70 nm layer provides very small signals for the RlfS-measurements due to the poor interference pattern. For this method, the layer thickness should be at least 100 nm. By the use of thicker layers of e.g. 205-455 nm, good interference patterns can be obtained which result in higher signals. The disadvantages of thicker layers are the slower interaction kinetics which lead to longer sorption and regeneration times. 

Short regeneration time requires a higher steaming rate, thus increasing the heat duty of the condenser system. 

Fig.3. Kinetic Data of Steamed Catalysts [Regeneration Time vs -ln(l-X)]...

Total regeneration time is between 5 and 20 minutes, depending, to a great extent, on VOC load and concentration as well as the quantity of co-adsorbed water. It can be assumed that VOC equilibrium is established between gaseous and solid phase at a regeneration temperature between 120°C and 220°C and a desorption gas velocity of roughly 0.01 m/s. Emichment factors (maximum regeneration gas concentration / raw gas concentration) of up to 1000 were achieved. 

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