Recovery, latent

Most refrigeration systems are essentially the same as the heat pump cycle shown in Fig. 6.37. Heat is absorbed at low temperature, servicing the process, and rejected at higher temperature either directly to ambient (cooling water or air cooling) or to heat recovery in the process. Heat transfer takes place essentially over latent heat profiles. Such cycles can be much more complex if more than one refrigeration level is involved. 

Selection of the high pressure steam conditions is an economic optimisation based on energy savings and equipment costs. Heat recovery iato the high pressure system is usually available from the process ia the secondary reformer and ammonia converter effluents, and the flue gas ia the reformer convection section. Recovery is ia the form of latent, superheat, or high pressure boiler feedwater sensible heat. Low level heat recovery is limited by the operating conditions of the deaerator. 

Which of these forms is most stable Surprisingly, the active form is less stable than the latent form. Conversion from the active to the latent form can occur spontaneously over a period of hours or days in vitro and more quickly under mild denaturing conditions. In contrast, recovery of the active form from the latent form requires complete unfolding of the latent form... 

Heat recovery section of an AHU The part of an AHU in which a sensible or latent heat gain or loss takes place by means of a heat-transfer medium. 

Because errors are frequently recoverable, it is also appropriate to define another category of errors, recovery failures. These are failures to recover a chain of events leading to a negative consequence (assuming that such a recovery was feasible) before the consequence occurs. This includes recovery from both active and latent failures. 

Recovery Error/Failure A recovery failure occurs if a potentially recoverable active or latent error is not detected or remedial achon is not taken before the negative consequences of the error occur. 

The cleanliness of products of combustion from gas enable recovery of latent heat by means of condensing appliances in which the products are cooled below the dewpoint of 55°C. The condensate is only weakly acidic and a suitable choice of materials of manufacture permit it to be dealt with. Most other fuels produce a condensate which is too acidic to allow condensing appliances to be used. 

A recent development in heat recovery has been the heat tube. This is a sealed metal tube which has been evacuated of air and contains a small quantity of liquid which, for boiler applications, could be water. When heat from the flue gases is applied to one end of the heat pipes the water in the tube boils, turning to steam and absorbing the latent heat of evaporation. The steam travels to the opposite end of the tube which is surrounded by water, where it gives up its latent heat, condenses and returns to the heated end of the tube. Batteries of these tubes can be arranged to form units, usually as a water jacket around a section of a flue. 

In the case when one of the two measurements of the contingency table is divided in ordered categories, one can construct a so-called thermometer plot. On this plot we represent the ordered measurement along the horizontal axis and the scores of the dominant latent vectors along the vertical axis. The solid line in Fig. 32.9 displays the prominent features of the first latent vector which, in the context of our illustration, is called the women/men factor. It clearly indicates a sustained progress of the share of women doctorates from 1966 onwards. The dashed line corresponds with the second latent vector which can be labelled as the chemistry/ other fields factor. This line shows initially a decline of the share of chemistry and a slow but steady recovery from 1973 onwards. The successive decline and rise are responsible for the horseshoe-like appearance of the pattern of points representing... 

The overall interpretation of the LLM biplot of Fig. 32.11 is the same as obtained with the CFA biplot of Fig. 32.10. The first (horizontal) latent variable seems to be associated primarily with the women/men contrast, while the second (vertical) latent variable is mostly associated with the chemistry/all fields contrast. Thermometer plots, which represent the scores of the various time intervals as a function of time, are similar to those in Fig. 32.9. They are not reproduced here as they point to the same remarkable events, i.e. the sustained rise of the proportion of women since 1966 and the recovery of the share of chemistry in 1973. 

Bjurstrom, H., and B. Carlsson, 1985. An exergy analysis of sensible and latent heat storage, Heat Recovery Syst., 5, 233-250. 

Ease of recovery. It is always desirable to recover the solvent for reuse. This is often done by distillation. If this is the case, then the solvent should be thermally stable and not form azeotropes with the solute. Also, for the distillation to be straightforward, the relative volatility should be large and the latent heat of vaporization small. 

In practice the presence of all three ways of intervening are needed. It is not possible to eliminate all latent conditions and there will always be conditions leading to possible ineffective safety barriers and ineffective control elements, which subsequently lead to precursors. Therefore, recovery is necessary, to intervene and arrest the precursors and ineffective safety barriers from evolving into a possible accident. Finally, because not all precursors can be effectively recovered, finally an overview of affected safety barriers is necessary to prevent an alignment of ineffective safety barriers and the presence of precursors that can escalate into an accident. 

Evaporation is achieved by adding heat to the solution to vaporise the solvent. The heat is supplied principally to provide the latent heat of vaporisation, and, by adopting methods for recovery of heat from the vapour, it has been possible to achieve great economy in heat utilisation. Whilst the normal heating medium is generally low pressure exhaust steam from turbines, special heat transfer fluids or flue gases are also used. 

Fischer, J.C. (1988) High efficiency sensible and latent heat exchange media with selected transfer for a total energy recovery wheel. US Patent 4,759,053. 

Industrial examples of adsorbent separations shown above are examples of bulk separation into two products. The basic principles behind trace impurity removal or purification by liquid phase adsorption are similar to the principles of bulk liquid phase adsorption in that both systems involve the interaction between the adsorbate (removed species) and the adsorbent. However, the interaction for bulk liquid separation involves more physical adsorption, while the trace impurity removal often involves chemical adsorption. The formation and breakages of the bonds between the adsorbate and adsorbent in bulk liquid adsorption is weak and reversible. This is indicated by the heat of adsorption which is <2-3 times the latent heat of evaporahon. This allows desorption or recovery of the adsorbate from the adsorbent after the adsorption step. The adsorbent selectivity between the two adsorbates to be separated can be as low as 1.2 for bulk Uquid adsorptive separation. In contrast, with trace impurity removal, the formation and breakages of the bonds between the adsorbate and the adsorbent is strong and occasionally irreversible because the heat of adsorption is >2-3 times the latent heat of evaporation. The adsorbent selectivity between the impurities to be removed and the bulk components in the feed is usually several times higher than the adsorbent selectivity for bulk Uquid adsorptive separation. 

Next there is eye pain, lacrlmation, blepharospasm, rhinorrhea, sail-vatlon, nausea, and vomiting. Recovery Is usually complete 1-2 h after exposure. The onset of symptoms is, however, delayed for several minutes, In contrast with the onset of symptoms after exposure to CS and CN, which have very short latent periods—this permits the absorption of much more DM before a warning Is perceived. 

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