Mechanical separation equipment from solids

Steam Purity. The trend toward higher pressures and temperatures in steam power plant practice imposes a severe demand on steam-purification equipment for elimination of troublesome solids in the steam. Carryover may result from ineffective mechanical separation and from the vaporization of boiler-water salts. Total cany-over is the sum of the mechanical and vaporous carry-over of all impurities. 

Dinitroaniline from 3 5-dinItrobenzoic acid. Place a solution of 50 g. of 3 5-dinitrobenzoic acid (Section IV, 168) in 90 ml. of 10 per cent, oleum and 20 ml. of concentrated sulphuric acid in a 1-litre three necked flask equipped with a reflux condenser, mechanical stirrer, adropping funnel, and thermometer (FUME CUPBOARD ). Add 100 ml. of clJoroform and raise the temperature to 45°. Stir rapidly and add 17 -5g. of sodium azide in small portions whilst maintaining the temperature at 35-45°. The reaction is accompanied hy foaming, which usually commences after about 3 g. of sodium azide has been introduced. After all the sodium azide has been added raise the temperature so that the chloroform refluxes vigorously and maintain this temperature for 3 hours. Then cool the reaction mixture, pour it cautiously on to 500 g. of crushed ice, and dilute with 3 litres of water. After 1 hour, separate the yellow solid by filtration at the pump, wash well with water and dry at 100°. The yield of 3 5-dinitroaniline, m.p. 162-163°, is 39 g. The m.p. is unaffected by recrystallisation from dilute alcohol. 

Filtration separates cells from a fluid by forcing the fluid through a porous filter medium, which deposits solids as liquids pass through. Vacuum or positive-pressure equipment is used to create the driving force for filtration. The main advantages of filtration include high rates of separation, low cost, mechanical simplicity, and relative ease of maintenance. However, it can have a low retention or poor containment, and can require the addition of a filter aid to ensure good filtration when solids accumulate on the membrane. 

Corrosion due to mechanical and metallurgical problems also exist. Metal tools used in drilling wells are often softer than the formation being penetrated. The abrasiveness of formation solids can easily erode protective films from drilling equipment, leaving metal exposed to corrosion-erosion attack. Mechanical and chemical separation of abrasive solids helps control this attack. It is difficult, however, to control stress concentrations in a string of driU pipe that may reach many kilometers into the earth. 

A solution of 10.0 g. (0.25 mole) of sodium hydroxide in 250 ml. of water is prepared in a 1-1. round-bottomed flask equipped with a reflux condenser and a mechanical stirrer. Twenty-five grams (0.065 mole) of N,N-dimethylaminomethylferrocene methiodide is added to the solution. The resulting suspension is heated to reflux temperature with stirring. At this point the solid is in solution. Within 5 minutes oil starts to separate from the solution and trimethylamine starts to come off. At the end of 3.5 hours, at which time the evolution of the amine has virtually ceased, the reaction mixture is allowed to cool to room temperature. The oil generally crystallizes during the cooling. The mixture is stirred with 150 ml. of ether until the oil or solid is all dissolved in the ether. The ether layer is separated in a separatory funnel and the aqueous layer is extracted with two additional 150-ml. portions of ether. The combined ether extracts are washed once with water and dried over sodium sulfate. 

The crude ester is cooled, an equal volume of benzene is added, then the free acid is neutralized by shaking with about 250 cc. of a 10 per cent solution of sodium carbonate (Note 4). The benzene solution is poured into 1300 cc. of a saturated solution of sodium bisulfite (about 60 g. of technical sodium bisulfite per 100 cc.), contained in a wide-neck bottle equipped with an efficient stirrer, and the mixture stirred for two and a half hours. The mixture soon warms up a little and becomes semi-solid. It is filtered through a 20-cm. Buchner funnel and carefully washed, first with 200 cc. of a saturated solution of sodium bisulfite, finally with two 150-cc. portions of benzene (Notes 5 and 6). The white pearly flakes of the sodium bisulfite addition product are transferred to a 3-I. round-bottom wide-neck flask equipped with a mechanical stirrer and containing 700 cc. of water, 175 cc. of concentrated sulfuric acid, and 500 cc. of benzene. The flask is heated on a steam bath under a hood, the temperature being kept at 55°, and the mixture is stirred for thirty minutes (Note 7). The solution is then poured into a separatory funnel, the benzene separated and the water layer extracted with a 200-cc. portion of benzene. The combined benzene solution is shaken with excess of 10 per cent sodium carbonate solution to remove free acid and sulfur dioxide (Note 8). The benzene is washed with a little water and then dried over anhydrous potassium carbonate (Note 9). The benzene is distilled at ordinary pressure over a free flame from a 500-cc. Claisen flask, the solution being added from a separatory funnel as fast as the benzene distils. It is advisable to distil the ester under reduced pressure although it can be done under ordinary pressure. The fraction distilling around n8°/5mm., 130710 mm., 138715 mm., 148725 mm., 155735 mm., or... 

Dissolve 71 g. of P-methylnaphthalene in 460 g. (283 ml.) of A.B. carbon tetrachloride and place the solution in a 1 -litre three-necked flask equipped with a mechanical stirrer and reflux condenser. Introduce 89 g. of JV-bromosuccinimide through the third neck, close the latter with a stopper, and reflux the mixture with stirring for 16 hours. Filter ofiT the succinimide and remove the solvent under reduced pressure on a water bath. Dissolve the residual brown oil (largely 2-bromomethyl naphthalene) in 300 ml. of A.R. chloroform, and add it to a rapidly stirred solution of 84 g. of hexamine in 150 ml. of A.R. chloroform contained in a 2-litre three-necked flask, fitted with a reflux condenser, mechanical stirrer and dropping funnel maintain the rate of addition so that the mixture refluxes vigorously. A white solid separates almost immediately. Heat the mixture to reflux for 30 minutes, cool and filter. Wash the crystalline hexaminium bromide with two 100 ml. portions of light petroleum, b.p. 40-60°, and dry the yield of solid, m.p. 175-176°, is 147 g. Reflux the hexaminium salt for 2 hours with 760 ml. of 60 per cent, acetic acid, add 160 ml. of concentrated hydrochloric acid, continue the refluxing for 5 minutes more, and cool. Extract the aldehyde from the solution with ether, evaporate the ether, and recrystallise the residue from hot -hexane. The yield of p-naphthaldehyde, m.p. 69-60°, is 60 g. 

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