Tubes loading

Substance Expected concentration range (ppm) (mg/m ) Recommended sampling - (ml/min) 2 hr 4 hr 8 hr Recommended maximum tube load (mg) Approximate desorption efficiency " (%) Eluent ... 

A recovery of 5% of the total sample from the back-up section of charcoal in a sample tube was defined as the breakthrough point 50% of this value is shown as the recommended maximum tube loading, to allow for high humidity or the presence of other substances which reduce the normal tube capacity. 

Determine condensing coefficient tube loading. Figure 10-67A. 

Because of the low tube loading and physical properties of condensate, the value of the film coefficient is beyond the range of the chart. Therefore, the use of a hjo of 1,500 is conservative. 

It is to be noted that only the steam-condensing coefficient will change (lower tube loading, increasing hjo). Because an arbitrary maximum value was used for coefficients, the overall U will not change nor will the At. Therefore, only the available area of the new sized unit needs to be checked against the previously calculated required area. For a 12-in. shell with 32 tubes available ... 

W" = tube loading for condensing, Ib/hr (ft of finned tube length). 9 ... 

Traditionally, the steam reforming reactor has a tubular design in which vertical tubes, loaded with catalyst, are surrounded by furnaces to supply the heat required for the strongly endothermic process, see Fig. 8.2. Combustion of natural gas supplies the heat to the tubes. 

T = the tube loading, the condensate flow per unit length of tube, kg/m s. 

Polymeric membrane-based implantable drug delivery systems have been developed to deliver growth hormone, hormonal contraception, and leuprolide for the treatment of prostate cancer. Implanted sialic tubes loaded with lev-onorgestrel Norplant system) is used outside the United States to provide five years of sufficient sustained release of the... 

Tests were performed to determine the stability of sorbed analytes in tubes that had been exposed to generator effluent and that were then stored for at least 7 d. For each method, the analyte concentration in the generator effluent was maintained at about 0.3 X LAQL per liter 3 L of the generator atmosphere was sampled at a rate of 0.2 L/min to yield a tube loading of about the LAQL. Following exposure, the sorbent tubes were sealed with Teflon tape and plastic caps for storage. 

Figure 17.34. Temperature and conversion profiles in a water-cooled shell-and-tube phosgene reactor, 2-in. tubes loaded with carbon catalyst, equimolal CO and Cl2.

After centrifugation, collect about 20 fractions (0.5 ml) from each gradient tube, load 5 to 10 fA from each fraction directly onto a 0.7% agarose gel, and electrophorese. 

This criterion establishes the maximum amount of material that can be vaporized with a falling-film vaporizer. Approximately 85 percent of the entering material can be vaporized in a single pass without destroying the film. If tube loadings below the terminal loading are attempted, the film will break and form rivulets. Part of the tube surface will not be wetted, and the result will be reduced heat transfer with possible increased fouling of the heat-transfer surface. 

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