Gas outlet

Impingement demister systems are designed to intercept liquid particles before the gas outlet. They are usually constructed from wire mesh or metal plates and liquid droplets impinge on the internal surfaces of the mist mats or plate labyrinth as the gas weaves through the system. The intercepted droplets coalesce and move downward under gravity into the liquid phase. The plate type devices or vane packs are used where the inlet stream is dirty as they are much less vulnerable to clogging than the mist mat. 

Boron trifluoride method. Fit a 1 litre three-necked flask with a gas inlet tube, a gas outlet leading to an alkali trap (compare Fig. 11,8, laori for the unabsorbed boron trifluoride), and stopper the third neck. Place 68 g. (73 ml.) of pure, anhydrous acetone (1) and 255 g. (236 ml.) of A.R. acetic anhydride in the flask and cool in a freezing mixture of ice and salt. Connect the gas inlet tube through an empty wash bottle to a cylinder of commercial boron trifluoride (2), and bubble the gas through the reaction mixture at such a rate that 250 g. is absorb in about 5 hours (2 bubbles per second). Pour the reaction mixture into a solution... 

An even less complicated reaction vessel may be used for reactions in liquid amtnonia which produce only a small amount of "heat" over a relatively long period and which proceed under homogeneous conditions. The conversion can then be performed in a one-necked flask with a stopper + gas outlet or small hole. 

Ayparatue. 2-1 three-necked round-bottomed flask with a dropping funnel, combined with a gas inlet, a mechanical stirrer and a thermometer, combined with a gas outlet. 

Apparatus-. 1-1 three-necked, round-bottomed flask with a thermometer+gas outlet, a stirrer and a gas inlet. During the experiment a slow stream of nitrogen was passed through the flask. A Dewar flask containing liquid nitrogen (note 1) was used as a cooling bath. 

To a solution of 0.50 tnol of ethyllithium in about 450 tnl of diethyl ether (see Chapter II, Exp. 1) was added 0.20 mol of 1-heptyne or butylallene (see Chapter VI, Exp. 1) with cooling below Q°C. After the addition the cooling bath was removed and the thermometer-gas outlet combination was replaced with a reflux condenser. The solution was heated under reflux for 6 h. The thermometer-gas outlet was again placed on the flask and the yellow suspension was cooled to -50°C. Trimethylchlorosilane (0.20 mol) was added dropwise in 10 min, while keeping the temperature between -40 and -35°C. After having kept the mixture for an additional 30 min at -30°C, it was poured into 200 ml of ice-water. The aqueous layer was extracted three times with small portions of diethyl ether. 

Apparatus 4-1 flask (see Fig. 2) for the reaction with lithium amide 3-1 silvered Dewar flask, provided with a rubber stopper and a gas outlet for the hydroxyalkylation (no stirring was applied). 

After the addition of the propyne the thermometer-gas outlet combination was replaced with a "cold finger" filled with dry-ice and acetone. The top of this reflux condenser was connected via a plastic tube with a cold trap (-75°C) containing 50 ml of dry THF. The cooling bath was removed and the conversion of propyne started... 

Apparatus 200-ml round-bottomed, three-necked flask provided with a gas inlet, a thermometer and a gas outlet magnetic stirring. 

A solution of methylmagnesium bromide in 150 ml of diethyl ether, prepared from 0.5 mol of methyl bromide (see Chapter II, Exp. 5) was subsequently added in 20 min with cooling at about 20°C. After the addition the mixture was warmed for 2 h under reflux (the thermometer and gas outlet were replaced with a reflux condenser), a black slurry being formed on the bottom of the flask. The mixture was cooled in a bath of dry-ice and acetone and a solution of 30 g of ammonium chlori.de in 200 ml of water was added with vigorous stirring. The organic layer and four ethereal extracts were combined, dried over potassium carbonate and subsequently concentrated in a water-pump vacuum. Careful distillation of the residue through a 40-cm... 

Apparatus. 500-ml round-bottomed, three-necked flask with a gas inlet tube, thermometer and a gas outlet for the preparation of chlorotetrahydropyran 1-1 four--necked, round-bottomed flask with a gas inlet tube, a dropping funnel, a mechanical stirrer and a thermometer, combined with a gas outlet for the preparation of HC=CMgBr and its reaction with chlorotetrahydropyran 1-1 three-necked, round--bottomed flask with a dropping funnel, combined with a gas inlet, a mechanical Stirrer and a thermometer, combined with a gas outlet for the conversion into the allenic alcohol. 

Appavatus-. For the first reaction a 500-ml round-bottomed flask with a thermometer and a gas outlet, connected with a tube filled with calcium chloride for the second reaction a 100-ml round-bottomed flask with a thermometer. 

Apparatus 2-1 rojnd-bottomed, three-necked flask with a mechanical stirrer, a stopper and a gas outlet. 

Apparatus. 2-1 three-necked, round-bottomed flask, provided with a gas inlet tube, a gas-tight mechanical stirrer and a gas outlet two washing bottles filled with paraffin oil were connected with the gas inlet and outlet. 

Apparatus. 1-1 flask, see Chapter 1, Fig. 1, the thermometer-gas outlet combination was replaced with a reflux condenser. 

Normally vessels are designed with the gas outlet location well above TDH. If circumstances force operation with a bed height so that the outlet is below TDH, an equivalent velocity, an effective velocity higher than the actual superficial gas velocity, is used ia the above calculation. The effective gas velocity can be determined from Figure 19 (27). 

The temperature driving force for drying is the difference between the drying-gas outlet temperature and, in the case of pure water, the gas wet-bulb temperature. In the case of a solution, the adiabatic saturation temperature of the pure saturated solution is employed rather than the wet-bulb temperature. 

As with dust cyclones, no reliable pressure-drop equations exist (see Sec. 17), although many have been published. A part of the problem is that there is no standard cyclone geometry. Calvert (R-12) experimentally obtained AP = 0.000513 J Q /hiWi) 2.8hiWi/dl), where AP is in cm of water Pg is the gas density, g/cm is the gas volumetric flow rate, cmVs hj and Wj are cyclone inlet height and width respectively, cm and is the gas outlet diameter, cm. This equation is in the same form as that proposed by Shepherd and Lapple [Ind. Eng. Chem, 31, 1246 (1940)] but gives only 37 percent as much pressure drop. 

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