Steam notes

In a 12-1. flask fitted with a mechanical stirrer and a short reflux condenser are placed 1800 g. (32.2 moles) of iron filings (Note i), 3 1. (52.5 moles) of glacial acetic acid, 3 1. of water, and 450 g. (3.95 moles) of heptaldehyde (Note 2). The mixture is heated on the steam bath, with stirring, for six to seven hours (Note 3). The flask is then fitted to an apparatus for steam distillation (Org. Syn. 2, 80) and the mixture distilled in a current of steam (Note 4) until no more oil passes over (7-8 1. of distillate). The oil is then separated, and the aqueous part distilled to recover a small quantity of dissolved or suspended heptyl alcohol. 

A mixture of 66.5 g. (0.5 mole) of tetrahydroquinoline and 400 g. of trimethylene chlorobromide (Note 1) is placed in a 1-1. round-bottomed flask attached to a reflux condenser, and heated in an oil bath held at 150-160° for 20 hours (Note 2). The reaction mixture is cooled, a solution of 50 ml. of concentrated hydrochloric acid in 500 ml. of water is added, and the excess trimethylene chlorobromide is removed by distillation with steam (Note 3). The acid residue from the steam distillation is made alkaline with a 40% solution of sodium hydroxide (about 75 ml.), and the julolidine is extracted with two 150-ml. portions of ether. The ethereal solution is washed with ISO ml. of water and dried over sodium hydroxide pellets. The ether is evaporated and the residue distilled under reduced pressure. The portion that boils at 105-110°/ mm. is collected (Notes 4 and 5). The yield is 67-70 g. (77-81%). 

The crude product (Note 2) is transferred to a 2-I. flask and mixed thoroughly with 200 g. of powdered calcium carbonate. About 300 cc. of water is added and the mixture is heated cautiously (Note 3) and then refluxed for fifteen hours to effect hydrolysis. The product is then distilled in a rapid current of steam (Note 4), and the distillate is collected in soo-cc. portions, cooled, and the />-bromobenzaldehyde is collected and dried in a desiccator. From the first liter of distillate 50-60 g. of -bromo-benzaldehyde melting at 55-57° is obtained. An additional... 

The aqueous acid solution is transferred to a i-l. round-bottomed flask provided with a separatory funnel and equipped for steam distillation. A solution of 125 g. of sodium hydroxide in 250 cc. of water is added through the funnel, and the mixture is distilled with steam (Note 4). The first liter of distillate contains most of the amine, but the distillate should be collected until it is only faintly alkaline. A small residue containing di-(a-phenylethyl)-amine and neutral substances remains in the flask and may be discarded. 

The flask is then cooled in ice, and in the course of about 20 minutes 83 g. of tin tetrachloride (37 ml., 0.32 mole) is added with vigorous stirring (Note 5). The mixture is heated at the reflux temperature for 1 hour, after which the condenser is set for distillation. During 1.5 hours the ether is rem ved by distillation while the flask is heated by an ample supply of steam (Notes 6 and 7). 

The solution is now saturated with salt and distilled with steam (Note 2). About 2 1. of distillate is required before all of the o-chlorocyclohexanol passes over. The distillate is saturated with salt and the oily layer separated. The aqueous layer is extracted once with about 250 cc. of ether. This is added to the main portion, which is dried with anhydrous sodium sulfate. The ether is removed by distillation and the product distilled under reduced pressure. The fraction boiling between 88-go°/2o mm. (io4-io6°/4S mm.) is collected. The yield is 142-148 g. (70-73 per cent of the theoretical amount). 

FIGURE 19.1 Simplified Mollier diagram for steam. (Note 1 psia = 6.895 kPa.)... 

Incompatibilities and Reactivities Chemically-active metals such as sodium, potassium, calcium, powdered aluminum, zinc magnesium oxidizers water or steam [Note Reacts with water to form hydrochloric acid.]... 

Incompatibilities and Reactivities Metals, vtrater or steam [Note Corrosive to metals. Will attack glass and concrete ]... 

It is impossible to generalize the effect of steam drying on product quality. Table 20.2 gives a summary of tests carried out at McGill University on batch drying of hand-sheets in a static apparatus in which the samples were dried under an impingement flow of superheated steam. Note that the effects are all positive relative to air drying or, at most, comparable. In Finland, similar tests on paper dried on a dynamic pilot-scale apparatus have yielded comparable results. 

We can confirm that steam2 is the transpose of steam by typing steam = (note not =). 

A steam drum, wherein steam is formed from water and water is separated from the steam (note the steam drum is omitted in certain once-through systems)... 

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