Contents 6 Continuous Lumping

To 1035 g. of syrupy arsenic acid (80-85 Per cent, sp. gr. 2.00/200 Note 1) in a 12-inch evaporating dish, is added 828 g. (800 cc.) of aniline (Note 2) in 100-cc. portions meanwhile, the lumps of aniline arsenate which are formed are broken up by rapid stirring with a porcelain spatula. When all the aniline has been added, the powdered solid is transferred to a 3-I. round-bottom flask equipped with a mechanical stirrer, a thermometer reaching to the lower part of the vessel, and a condenser arranged for downward distillation (Note 3) an additional 800 cc. of aniline is added and the flask slowly heated in an oil bath. The bath may be kept at a temperature not exceeding 170-175° as long as there is any considerable amount of unmelted material in the flask. When the contents of the flask have become liquid the temperature of the bath is dropped and the mixture held at 155-160° (inside temperature), with continual stirring, for at least four and a half hours. The mass will have assumed an intense violet color. 

The wood burns out in about sixty hours after lighting, but the ore continues to burn for three or four months, its speed of combustion being regulated by control of the draught. The outside portions of ore assume a reddish tint in consequence of the oxidation of iron frequently the interior of lumps of ore remain unchanged throughout On the average, however, the sulphur content is reduced from 23 per cent, in the raw ore to 10 or 12 per cent, in the roasted material. 

At higher lime contents, free lime is present in the clinkers. The Ca(OH)2 or Mg(OH)2 formed upon hydrating free lime (CaO or MgO) takes up more space than the original oxide. Therefore, CaO (or MgO) in coarse crystalline lumps gives rise to so-called lime bursting (or magnesia bursting ), since the reaction with water is very slow and continues after the cement is hard. 

When solid NaOH or KOH was introduced into the space between the electrodes in a 5 mm lumps and a discharge in ammonia was operated at 5 torr and 5 mA the hydrazine content increased by a factor of about seven (Fig. 24). However, the continuous operation of the discharge caused the catalyst to melt. With intermittent operation of the discharge the catalyst did not melt and the degree of conversion into hydrazine reached 15%, double that obtained with a continuous discharge (Fig. 24). The effect was explain l by assuming that the formation of hydrazine... 

When a liquid flow is introduced into a stirred reactor, such as in semi-batch or in fully continuous operation, the mixing of this flow with the reactor contents may be critical, particularly in turbulent flow conditions. This effect is known as meso-mixing. The incoming liquid forms a jet that is surrounded by a turbulent stream of liquid that circulates in the reactor. The jet will be broken up from the outside into small lumps of liquid these will deform and become engulfed by the surrounding liquid (Baldyga and Bourne, 1992, Baldyga et al., 1993). 

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