Reheat additives

Crystallization of the Terpolymer in the Mixture. Crystallization of the terpolymer occurred in samples containing 60% or more of the terpolymer when cooled from the melt at a rate of 40°C/min. The specimen containing 40% terpolymer at first did not exhibit a measurable exotherm because of crystallization, although a small amount of crystals was detected in the sample upon subsequent reheating. Additional cooling studies conducted at 40°, 20°, 10°, and 5°C/min on samples con-... 

When the addition of the bromobenzene is complete and the ether is boiling gently, reheat the flask on the water-bath for a further 15 minutes to ensure completion of the reaction the solution will now be slightly dark in colour, and only a trace of metallic magnesium should remain. 

Now remove the flask from the water-bath, and slowly add a solution of 5 ml. (5-2 g.) of dry ethyl benzoate in 15 ml. of anhydrous ether down the condenser in small quantities at a time, mixing the contents of the flask thoroughly between each addition. When the boiling of the ether again subsides, return the flask to the water-bath and reheat for a further 15 minutes. Then cool the mixture in ice-water, and carefully pour off the ethereal solution into a mixture of about 60 ml. of dilute sulphuric acid. and 100 g. of crushed ice contained in a flask of about 500 ml. capacity fitted for stearn-distillation, taking care to leave behind any unchanged magnesium. 

Although this material is suitable for most purposes, it may be purified further in the following manner. It is dissolved by heating in a solution of 2 g. of stannous chloride and 2 cc. of concentrated hydrochloric acid in i 1. of water, and the hot solution is clarified by filtration through a 5-mm. mat of decolorizing carbon (Note g). The yellow or red color which may develop disappears on reheating to the boiling point. After the addition of 100 cc. of concentrated hydrochloric acid the solution is allowed to cool in an ice bath, treated with a second roo cc. of acid, cooled to 0°, and collected and washed as befor The ciystalline product is colorless, ash-free, and of analytical purity. The loss in the crystallization of an 80-g. lot amounts to 5-10 g. (6-12 per cent). 

Fig. 1.10 shows the processes of heat exchange (or recuperation), reheat and intercooling as additions to a JB cycle. Heat exchange alone, from the turbine exhaust to the compressed air before external heating, increases and lowers so that the overall... 

A set of calculations using real gas tables illustrates the performance of the several types of gas turbine plants discussed previously, the [CBT]ig, [CBTX]ig, [CBTBTX]ig, [CICBTXIig and [CICBTBTX]ig plants. Fig. 3.15 shows the overall efficiency of the five plants, plotted against the overall pressure ratio (r) for = 1200°C. These calculations have been made with assumptions similar to those made for Figs. 3.13 and 3.14. In addition (where applicable), equal pressure ratios are assumed in the LP and HP turbomachinery, reheating is set to the maximum temperature and the heat exchanger effectiveness is 0.75. 

While the lowest and highest optimum pressure ratios are for these two plants, the addition of reheating and intercooling increases the optimum pressure ratios above that of... 

At temperatures in excess of 750°C the addition of water vapour accelerates the rate of growth of FeO (Fig. 7.10) by producing large pores in the FeO" . At much higher temperatures (1 200°C) Sheasby et have found that addition of steam to Oj-Nj, Oj-HjO-Nj and HjO-Nj, in a simulated reheating atmosphere furnace, caused increases in scale growth due to improved adhesion at the scale/metal interface. They concluded that water vapour enhances scale creep as previously reported by Tuck et... 

The first part is identical to that in Example 24.8, and the second step is the addition of sensible heat in a reheat coil. 

Superheaters and reheaters are tube bundles located in either the boiler furnace section or the convection-pass section. They are designed to increase the temperature of generated steam prior to its being passed to a turbine. Many larger power boiler designs incorporate a steam reheater in addition to one or two banks of superheaters. 

Boc-protected a,a-diatyl-L-prohnol (6) was placed in a sand bath under a weak vacuum somce (approx. 15 imuHg) and heated to 210°C. Ten minutes after the formation of bubbles had ceased. The reaction was cooled to room temperature and H-NMR was used to determine the extent of reaction. If the Boc group was still detectable by H-NMR, then the reaction was reheated to 210°C for an additional twenty minutes and allowed to cool and the extent of reaction was reevaluated by H-NMR. This procedtrre was repeated rmtil the Boc group cotrld not be detected by H-NMR. 

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