Experimental Drying Apparatus

First, an experimental drying apparatus is used. In such an apparatus, the air passes through the drying material and the air humidity, temperature, and velocity are controlled, whereas the material moisture content and, eventually, the material temperature are monitored versus time. Second, a mathematical model that takes into account the controlling mechanisms of heat and mass transfer is considered. This model includes the heat and mass transport properties as model parameters or, even more, includes the functional dependence of the relevant factors on the transport properties. Third, a regression analysis procedure is used to obtain the transport properties as model parameters by fitting the model to experimental data of material moisture content and temperature. 

An experimental drying apparatus similar to that shown in Figure 4.15 was used [35]. In each experiment, the air-water activity, temperature, and velocity were controlled, and the material moisture content and temperature were monitored versus time. A total number of 100 experiments were performed for three different particle dimensions (5, 10, and 15 mm) at five air temperature (60°C, 65°C, 70°C, 75°C, and 80°C), three air velocities (3,4, and 5 m/s) and at air hnmidity ranging from 6 to 22 g/kg db. 

First, an experimental drying apparatus is used. In such an apparatus, the air passes through the drying material and the air humidity, temperature, and velocity are controlled, whereas the material moisture content and, eventually, the material temperature are monitored versus time. Second, a mathematical... 

The measurement of the drying constant is obtained from drying experiments. In a drying apparatus, the air temperature, humidity, and velocity are controlled and kept constant, whereas the material moisture content is monitored versus time. The drying constant is estimated by fitting the thin-layer equation to experimental data. 

The experimental conditions for conducting the above reaction in the presence of dimethylformamide as a solvent are as follows. In a 250 ml. three-necked flask, equipped with a reflux condenser and a tantalum wire Hershberg-type stirrer, place 20 g. of o-chloronitrobenzene and 100 ml. of diinethylform-amide (dried over anhydrous calcium sulphate). Heat the solution to reflux and add 20 g. of activated copper bronze in one portion. Heat under reflux for 4 hours, add another 20 g. portion of copper powder, and continue refluxing for a second 4-hour period. Allow to cool, pour the reaction mixture into 2 litres of water, and filter with suction. Extract the solids with three 200 ml. portions of boiling ethanol alternatively, use 300 ml. of ethanol in a Soxhlet apparatus. Isolate the 2 2- dinitrodiphenyl from the alcoholic extracts as described above the 3ueld of product, m.p. 124-125°, is 11 - 5 g. 

The experimental details for mono-M-propylanillne are as follows. Reflux a mixture of 230 g. of aniline and 123 g. of n-propyl bromide for 8-10 hours. Allow to cool, render the mixture alkafine, and add a solution of 150 g. of zinc chloride in 150 g. of water. Cool the mixture and stir after 12 hours, filter at the pump and drain well. Extract the thick paste several times with boiling light petroleum, b.p. 60-80° (it is best to use a Soxhlet apparatus), wash the combined extracts successively with water and dilute ammonia solution, and then dry over anhydrous potassium carbonate or anhydrous magnesium sulphate. Remove the solvent on a water bath, and distil the residue from a Claisen flask with fractionating side arm (well lagged). Collect the n-propyl-aniline at 218-220° the yield is 80 g. Treat the pasty solid zincichloride with an excess of. sodium hydroxide solution and steam distil 130 g. of pure aniline are recovered. 

The experimental apparatus is consists of reformed gas feeding sections, CO PrOx reaction section in the reactor, and the analysis section with a gas chromatograph system. Simulated reformed gas composition was 75 vol.% H2, 24 vol.% CO2 and 1.0 vol.% CO. The dry reformed feed stream was fed with O2 (A.=l) into the microchannel reactor by MFC (Brooks 5850E). Water vapor (10vol.% of reformed gas) was also fed into the reactor by a s)ninge pump. 

For smaller scale operations or when catalytic amounts of impurities are important, a vacuum line is almost always more suitable and efficient. Although it takes longer to become familiar with a vacuum apparatus, once a certain degree of competence and confidence has been achieved, there is little to choose in terms of experimental time between h.v.t. and the rigorous use of a dry-box. The choice is often made simply on the basis of laboratory tradition (i.e. inertia) and know-how. 

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