Water trapping

A procedure using 48% HBr with a Dean-Stark water trap gives good yields of 4-bromobutanol [33036-62-3] free of diol and dibromo compound... 

The process of flushing typically consists of the foUowing sequence phase transfer separation of aqueous phase vacuum dehydration of water trapped in the dispersed phase dispersion of the pigment in the oil phase by continued appHcation of shear thinning the heavy mass by addition of one or more vehicles to reduce the viscosity of dispersion and standardization of the finished dispersion to adjust the color and rheological properties to match the quaHty to the previously estabHshed standard. 

Water Determination. The sample is refluxed with toluene and the resultant toluene—water a2eotrope is distilled iato a gradual water-trap receiver (Dean and Stark apparatus). Here the water and toluene separate iato two distinct layers, permitting the volume of water to be read and its percentage calculated. 

Figure 3-28 shows, as an example, results obtained from an intensive measurement of a short section of pipe which could be very strongly polarized to increase the sensitivity of defect location. From Eq. (3-51 a) Tq = 4 mm at = 0.1 V. In the results in Fig. 3-29, rg = 9 cm at AU = 0.1 V. These results are clear indications of water traps resulting from a poor coating [46]. Further examples are shown in Section 3.7. 

A mixture of 105.6 g. (1.1 moles) of freshly distilled furfural, 87.0 g. (1.0 mole) of 98% cyanoacetic acid (Note 1), 3.0 g. of ammonium acetate, 200 ml. of toluene, and 110 ml. of pyridine is placed in a 1-1. round-bottomed flask equipped with a Stark and Dean water trap and reflux condenser. The mixture is boiled under reflux for 2 days. The theoretical quantity of water is collected in the trap within 1 hour. Upon completion of the reflux period, the solvent is removed under reduced pressure by heating on a water bath. The residue, distilled through a 15-cm. Vigreux column at 11 mm. pressure, yields 88.6-93.3 g. (74.5-78%) of colorless liquid boiling at 95-97°, 1.5823-1.5825. 

A solution of 30 g (0.1 mole) of 17j5-hydroxy-5a-androstan-3-one (androstano-lone), 20 ml of pyrrolidine and 200 ml of benzene is heated at reflux temperature for 2.5 hr under a Bidwell-Sterling water trap. The benzene solution is evaporated to dryness in a rotating evaporator connected to a water aspirator. The white cake which remains is broken up and dried further by immersing the flask in a water bath at 60-75° and evacuating the flask with a mechanical vacuum pump. After 0.5 hr the solid cake is broken up again and dried for another 0.5 hr at 60-75°. The enamine (9) obtained should smell only faintly of pyrrolidine. 

The release of oil into the dike was due to boilover, that is, production of steam from the fire-fighting foam by the hot oil. As the steam leaves the tank, it brings oil with it. Boilover usually occurs when the heat from the burning oil reaches the water layer at the bottom of the tank, but in this case it occurred earlier than usual when the heat reached pockets of water trapped on the sunken roof [14]. 

Overhoff, K-H, Schecker, H-G, Fellensiek, J., and Oncken, U. 1989. Investigation for the Design of a New Water Trap Flame Arrester. International Symposium on Loss Prevention and Safety Promotion m the Process Industries, Paper 54. Oslo, Norway, June 19-22, 1989. 

Preparation of 11-Keto-6 -Methy progesterone 3,20-Bis-(Ethylene Ketal) A mixture of 5 g of 11-keto-6(3-methylprogesterone (Spero et al, 7. Am. them. Soc., 78, 6213 (1956)], 503 ml of benzene, 26 ml of ethylene glycol, and 0.152 g of p-toluenesulfonic acid monohydrate was stirred and heated under reflux for 22 hours while water was removed by means of a water trap. The reaction mixture was then cooled to 30°C, 0.4 ml of pyridine was added, and stirring was continued for 10 minutes. 

Check that the abrasive is not contaminated with moisture, dirt, spent abrasive, etc., that the blasting equipment can deliver the abrasive at an adequate pressure and that the airlines are fitted with a water trap. 

Design —good design to minimise exposed dissimilar metal couples, radius sharp edges and avoid water traps. Allow for protection of mating faces. 

The system should be relatively free of oxygen during irradiation. Oxygen apparently combines with a photochemical intermediate to form cyclohexanone.3 Under the conditions recommended in the procedure, oxygen is prevented from entering the system by the water trap which also serves as a monitor for gas evolution. 

The gases used were purchased premixed in aluminum cylinders to avoid carbonyl formation. The high purity gas mixture was further purified by a zeolite water trap and a copper carbonyl trap. The gas pressure in the reactor was measured with a capci-tance manometer and the fTow monitored with a mass fTow controT-ler. The typical gas flow rates were 15 cc/min (STP) and the maximum conversion was 1% based on integration of hydrocarbon products. The hydrocarbon products were analyzed by gas chromatography (temperature programmed chromosorb 102, FID). 

Acetylcyclohexanone. Method A. Place a mixture of 24-6 g. of cyclohexanone (regenerated from the bisulphite compound) and 61 g. (47 5 ml.) of A.R. acetic anhydride in a 500 ml. three-necked flask, fitted with an efficient sealed stirrer, a gas inlet tube reaching to within 1-2 cm. of the surface of the liquid combined with a thermometer immersed in the liquid (compare Fig. II, 7, 12, 6), and (in the third neck) a gas outlet tube leading to an alkali or water trap (Fig. II, 8, 1). Immerse the flask in a bath of Dry Ice - acetone, stir the mixture vigorously and pass commercial boron trifluoride (via an empty wash bottle and then through 95 per cent, sulphuric acid) as fast as possible (10-20 minutes) until the mixture, kept at 0-10°, is saturated (copious evolution of white fumes when the outlet tube is disconnected from the trap). Replace the Dry Ice-acetone bath by an ice bath and pass the gas in at a slower rate to ensure maximum absorption. Stir for 3 6 hours whilst allowing the ice bath to attain room temperature slowly. Pour the reaction mixture into a solution of 136 g. of hydrated sodium acetate in 250 ml. of water, reflux for 60 minutes (or until the boron fluoride complexes are hydrolysed), cool in ice and extract with three 50 ml. portions of petroleum ether, b.p. 40-60° (1), wash the combined extracts free of acid with sodium bicarbonate solution, dry over anhydrous calcium sulphate, remove the solvent by... 

Water taken up by solid materials is generally classified as water bound by physical forces or water bound by chemical bonds. Physically bound water includes adsorbed water, trapped or liquid-inclusion water, and absorbed water. The physical adsorption of water occurs when water condenses or is held on the surface the surface includes the cracks, crevices, etc. of real materials. Liquid inclusion occurs during the crystallization process when bubbles of water are trapped. 

FIGURE 26.32 Water traps in a gas-collector system. (Adapted from U.S. EPA, Requirements for Hazardous Waste Landfill Design, Construction, and Closure, EPA/625/4-89/022, U.S. Environmental Protection Agency, Cincinnati, OH, August 1989.)... 

Air conditioner condensate lines are sometimes installed so that they penetrate the slab to dispose of the water in the subslab area. Even when water is trapped, this can be a problem because the traps often dry up during the heating season. At this point they become radon entry routes. It is recommended that air conditioning condensate lines run to a drain that will not dry out or that a condensate pump is installed that collects the condensate and disposes of it through a water trap. Often a washing machine drain is located in a basement near enough to use it. 

---