Plume temperatures

Heskestad [19] determined this result for use with the centerline far-field plume temperature correlation for z > Zf, given as... 

These results apply to plume rise in a tall open space of air at a uniform temperature. The results can be important for issues of fire detection and sprinkler response. Plume rise in a thermally stratified stable (dT /dz > 0) atmosphere will not continue indefinitely. Instead, it will slow and eventually stop and form a horizontal layer. It will stop where its momentum becomes zero, roughly when the plume temperature is equal to the local ambient temperature. 

Turbulent fire plume temperatures do not generally exceed 1000 °C. This is well below the adiabatic flame temperature for fuels. Why ... 

An extremely fine localization of primordial 3He injection, on a 10-m scale, has also been observed. It has been suggested that lower-than-expected conductive heat flow at oceanic ridges could be due to significant heat transport by hydrothermal circulation (e.g., Talwani, Windisch Langseth, 1971), in which recently emplaced hot rock drives convection of local sea water. On the basis of temperature-salinity relationships, Weiss et al. (1977) made the first identification of hydrothermal circulation in the open ocean, observing several plumes (temperature differential <0.2°C)... 

The effective heat flow transferred to the craton from the ponded plume material over geological time can be estimated. For example, if we assume a 40 km equivalent thickness of 200 K excess plume temperature ponds on average at a spot under the craton every 300 Ma and that the volume specific heat is 4 x 10 JK m, then the average additional heat flow is 3.4mW m . This is a modest part of typical mantle heat flows from cratonal regions (e.g. Jaupart et al. 1998). 

The 12-pallet classification test results consider the number of opened sprinklers, maximum steel beam temperature at the ceiling, maximum plume temperature and velocity, maximum heat flux, maximum weight loss rate, and net percentage weight loss. The classification of a given aerosol product is based upon suppression or control of the fire and the number of sprinklers that opened during the fire test. An aerosol product is considered a Level 1 if the fire was well controlled or suppressed, a Level 2 if the fire was well to marginally well controlled or a Level 3 if the fire was not well controlled. 

Figure 5. He/ He vs. (a-left) buoyancy flux, (b-opposite page, upper) Lithosphere age. (e-opp. page, lower) Plate speed. Points show the highest e/" He ratios at eaeh island with dashed lines extending to the lowest values. Only crushing analyses are used to avoid post-eruptive addition of cosmogenie e and radiogenic ""He. Buoyancy flux is taken direetly from Davies (1988) or ealeulated from Sleep (1990) assuming an excess plume temperature of 200°C. He data are from Kurz et al. (1982a, 1983) for Gough, Tristan da Cunha and Hawaii Hilton et al.

The behavior of a plume is affected by a number of parameters, including the initial source conditions (exit velocity and difference between the plume temperature and that of the air), the stratification of the atmosphere, and the wind speed. Based on the initial source conditions, plumes can be categorized in the following manner ... 

Spray plume temperature Proventor HFA (Schering-Plough, Madison, NJ) produced a significantly softer and wanner aerosol spray than other products tested. Plume temperatures for various CFC and CFC-free salbutamol pMDIs are shown in Fig. 13. 

Figure 13 Plume temperature of CFC and CFC-free salbutamol MDIs. (From Ref. 85.)...

The energy balance for the plume temperature is given by the following equation. 

Plume dispersal, which will depend on, e.g., meteorological data, local topography, and plume temperature (which may cause the plume to rise). 

The spectral efficiency of a flare composition is closely related to the combustion enthalpy of the flare composition, the plume temperature and the spectral emissivity of its combustion products as described in Eq. (10.18)... 

Magnesium/Teflon /Viton In general, MTV flare formulations are fuel rich in order to take advantage of afterburning reactions with atmospheric oxygen. Afterburning alters the plume temperature and thus affects the radiant intensity, lx- The variation of the theoretical explosion enthalpy (anaerobic reaction) and overall combustion enthalpy Eq. 10.19 (a + h) as a function of stoichiometry... 

Figure 20.4 Predicted evolution of plume temperature and specie profiles downwind an open pit deflagration of MTV flare waste mixed with diesel fuel. (After Ref [2].)...

Even if these early observations are now explained differently, a high transient plume density is expected, as described above. The model runs into difficulty mainly in that plume properties are not sufficiently polar for extensive ion separation. Liquid, substituted aromatics somewhat similar to MALDI matrices typically have dielectric constants around or below 10 at room temperature (phenol 9.8, methyl salicylate 9.4, acetic acid 6.1). " In addition, at least a factor-of-two decrease could be expected at MALDI plume temperatures. For example, 1-butanol has a dielectric constant of 15 at room temperature, but 7 at 400°C. " Assuming the MALDI plume is a similarly solvating fluid, separation of ionic substances (including matrix itself) will be extremely limited. 

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