Absorption drying equipment

Drying equipment, 10 154 Drying gases, commercial gas absorption process for cellulose acetate fiber production, l 26t Drying index, 9 144 Drying mechanisms, 9 102-116. 

Even when adhering to technological parameters, certain amounts of sulphur dioxide, unreacted in the oxidation step (as much as 0.3 to 0.4% by volume in the final gases) may be released into the atmosphere. The final gases also contain sulphur trioxide and sulphuric acid aerosol, particularly in the case of inefficient operation of absorption and drying equipment. 

Iron concentrations in extracts were measured in triplicates with a Hitachi-Z8100 atomic absorption spectrophotometer equipped with a Zeeman correction system. The flame atomizer was used for extracts from total digestions and acid extractions the flameless graphite furnace was used for extracts of sulfidic iron. The contents of iron from sequential extractions were corrected for water contents (but not for salt contents) in sediments in order to get concentrations on a dry weight basis. Accuracy and precision for Fe analysis were checked by replicate extraction analysis (n = 5) of standard reference material BCSS-1, which is issued by the National Research Council, Canada and has a certified iron content of 3.287 0.098% our analytical value was 3.266 0.056%, indicating good accuracy of our analyses. The relative precision for iron determination in this study is better than 5%. 

Equip a 1 litre bolt-head flask with dropi)ing fuuncl and a double surface reflux condenser to the top of the latter attach a device (e.g.. Fig. II, 8, 1. c) for the absorption of the hydrogen bromide evolved. Place 100 g. (108 ml.) of dry iso-valeric acid (Section 111,80) and 12 g. of pmified red phosphorus (Section 11,50,5) in the flask. Add 255 g. (82 ml.) of dry bromine (Section 11,49,5) slowly through the dropping funnel at such a rate that little or no bromine is lost with the hydrogen bromide evolved the addition occupies 2-3 hours. Warm the reaction mixture on a water bath until the evolution of hydrogen bromide is complete and the colour of the bromine has disappeared. Pour off the liquid reaction product into a Claisen flask and distil mider the reduced pressure of a water pump. Collect the a-bromo-wo-valeryl bromide at 117-122°/25-30 mm. The yield is 150 g. 

Of the three categories, the packed column is by far the most commonly used for the absorption of gaseous pollutants. Miscellaneous gas-absorption equipment could include acid gas scrubbers that are commonly classified as either wet or diy. In wet scrubber systems, the absorption tower uses a hme-based sorbent liquor that reacts with the acid gases to form a wet/solid by-product. Diy scrubbers can be grouped into three catagories (1) spray diyers (2) circulating spray diyers and (3) dry injection. Each of these systems yields a diy product that can be captured with a fabric filter baghouse downstream and... 

A) 2-Bromophthalide.—The apparatus shown in Fig. 6 is used for the bromination. Flasks A and B are of 200-cc. capacity. Bromine is introduced by means of a current of carbon dioxide, which passes through mineral oil or sulfuric acid in the bubble counter, then through the bromine in flask B, and finally through the drying tower. The tower is conveniently made from a condenser jacket and is filled with anhydrous calcium chloride. Flask A is surrounded by an oil bath and is equipped with a thermometer, an outlet tube of wide bore connected to a gas absorption trap, and a gas inlet tube having an inside diameter of 2 mm. The inlet tube reaches to the bottom of the flask. 

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