Absorption heating

The simplest possible case occurs when (1) both the operating and the equilibrium hues are straight (i.e., there are dilute solutions), (2) Henry s law is valid y /x = yifXj = m), and (3) absorption heat effects are negligible. Under these conditions, the integral term in Eq. (14-20) may be computed by Colburn s equation [Trans. Am. Jn.st. Chem. Eng., 35,211 (1939)] ... 

In many practical situations involving nearly complete cleanup of the gas, an approximate result can be obtained from the equations just presented even when solutions are concentrated or when absorption heat effects are present. In such cases the driving forces in the upper part of the tower are very much smaller than those at the bottom, and the value of mGM/LM used in the eqiiations should be the ratio of the slopes of the equilibrium line m and the operating line Lm/Gm iu the low-concentration range near the top of the tower. 

Several factors influence a drug s absorption (table 3.1). Aqueous solutions are more easily absorbed than a lipid solution or solid form. Absorption of drugs in solid form is affected by the rate at which it dissolves. Higher concentrations of a drug are more rapidly absorbed than low concentrations. The amount of blood flow to the site also influences absorption heat and vasodilators increase absorption. 

Glass transition determinations Decomposition reaction Reaction kinetics Phase diagrams Dehydration reactions Solid-state reactions Heats of absorption Heats of reaction Heats of polymerization Heats of sublimation Heats of transition Catalysis... 

It is, in fact, a combination of properties such as compatibility, tensile strength (TS), % elongation (E), bond strength (BS) with propellant and explosive plasticizer (NG)/non-explosive plasticizer (TA,DEP,DOA,DOP etc.) migration or absorption, heat resistance and flame retardance which makes a polymer suitable for inhibition of solid propellants. A compromise among these properties is made in such a way that the performance of inhibited propellants after conditioning at ambient, cold (-40 °C) and hot (+60 °C) temperatures is satisfactory during static evaluation. 

Tn the critical region of mixtures of two or more components some physical properties such as light scattering, ultrasonic absorption, heat capacity, and viscosity show anomalous behavior. At the critical concentration of a binary system the sound absorption (13, 26), dissymmetry ratio of scattered light (2, 4-7, II, 12, 23), temperature coefficient of the viscosity (8,14,15,18), and the heat capacity (15) show a maximum at the critical temperature, whereas the diffusion coefficient (27, 28) tends to a minimum. Starting from the fluctuation theory and the basic considerations of Omstein and Zemike (25), Debye (3) made the assumption that near the critical point, the work which is necessary to establish a composition fluctuation depends not only on the average square of the amplitude but also on the average square of the local... 

The main factor that has been responsible for the slow adoption of absorption heat pumps for heating and air conditioning duties has been their high capital cost compared with that of vapor compression equivalents. This is due largely to the cycle complexity, as shown in Figure 14, which displays the four principal cycle elements, all of which involve vapor-liquid systems ... 

As part of a general development to use spinning discs in an intensified absorption heat pump, Aoune and Ramshaw (16) measured both the local and average heat transfer performance on smooth rotating surfaces. The disc surface... 

Figure 14 Single-effect absorption heat pump cycle.

Ramshaw C, Winnington TL. An intensified absorption heat pump. Proc Inst Refrig... 

Whilst early work indicated that for carbon dioxide absorption heat release could not be expected to be significant (2), Van de Vusse had already remarked in 1966 (2) that the absorption of chlorine into a hydrocarbon could produce flames at the interface. Around that time the heat effects accompanying ammonia absorption were estimated to give increases of around 15°C across the mass transfer film (3), and subsequently further treatments quantified temperatures up to U0°C (4,5,6). 

Knoche, K. F. and Stehmeier, D., "Exergetlc Criteria for the Development of Absorption Heat Pumps," AIChE National Meeting, Detroit, MI, Aug. (1981). 

Fast Reactions. Where reactions are essentially completed in times of seconds or much less, ingenious methods have been devised to give measurements of the rate. Such methods may involve static systems in which mixing is performed very rapidly. Also useful is excitation of the system by light for a specified period. A variant method involves a flow system in which reactants are rapidly mixed and flowed through a tube in which recording equipment can be employed to measure optical absorption, heat evolution (temperature), or electrical conductivity. The... 

BINARY-FLUID HEAT AND MASS TRANSFER IN MICROCHANNEL GEOMETRIES FOR MINIATURIZED THERMALLY ACTIVATED ABSORPTION HEAT PUMPS... 

Miniaturization of Absorption Heat and Mass Transfer Devices - Volatile Absorbents... 

COUPLED BINARY-FLUID ABSORPTION HEAT AND MASS TRANSFER MODEL... 

Table 2 Falling-Film Absorption Heat and Mass Transfer Model Overview...

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