Thick-walled reaction vessel

The reactivity of alkali metals with B decreases as their atomic number increases Li reacts completely with B at 700°C, whereas with K the reaction is not complete until 1200°C, at which T the pressure of the alkali metal is ca. 20 x 10 N m . These pressures demand the use of thick-walled reaction vessels. The boron-alkali metal mixture is placed in a Mo crucible inside such a container made of Fe or Mo, depending on the reaction T. 

Traditional nuclear power involves using the heat generated in a controlled fission reaction to generate electricity. A schematic of a nuclear reactor is shown in Figure 17.7. The reactor core consists of a heavy-walled reaction vessel several meters thick that contains fuel elements consisting of zirconium rods containing enriched pellets of U-235 in the form of... 

The reaction space itself is enclosed by an inner shell with relatively thin walls which is accommodated inside the thick-walled pressure vessel. The space between the inner and outer shells is filled with boiling water to cool the inside. This boiling water is pressurized to a level slightly higher than the reactor pressure it is used to generate steam which can be added to the gasifying agent. 

Fig. A.5. An apparatus for the lsO-labclling of the CO2 produced in biolumines-cence reactions. The stopcocks A-E and the ground joint of reaction vessel are lubricated with high-vacuum grease, and the connections between the glass tubes are made with short pieces of thick-walled silicon rubber tubing. The stopcocks C and D are high-vacuum type, such as Ace Glass, Cat. No. 8197-04 and 8195-236, or Corning, Cat. No. 7473-3.

Thus nickel and nickel-copper alloy films evaporated in vacuo onto the inner walls of the reaction vessel have been chosen for further investigations. The films were deposited onto the inner wall of a glass tube kept at 450°C their thickness amounted to approximately 2000 A. After annealing at the same temperature in vacuo they were transferred into the side-arm of the Smith-Linnett apparatus in order for the recombination coefficients to be determined. The bulk homogeneity of alloy films prepared in this way was confirmed by X-ray diffraction (65, 65a, 66). 

A jacketed reaction vessel containing 0.25 nv1 of liquid of specific gravity 0.9 and specific heat 3.3 kJ/kg K is heated by means of steam fed to a jacket on the walls. The contents of the tank are agitated by a stirrer rotating at 3 Hz. The heat transfer area is 2.5 nr ami the steam temperature is 380 K. The outside film heat transfer coefficient is 1.7 kW/m2 K and the 10 mm thick wall of the tank has a thermal conductivity of 6.0 W/m K... 

Reactions were performed in sealed thick-walled glass tubes or in Teflon acid-digestion vessels, in domestic microwave ovens [13]. Teflon vessels can be used at pressures up to 14 atm, at temperatures below 250 °C, and are resistant to most commonly used chemicals, although they deform at temperatures >250 °C. 

The amount of power dissipated into the reaction from the bath is not readily quantifiable because it will depend on the size of the bath, the reaction vessel type (and thickness of its walls) and the position of the reaction vessel in the bath. 

Preparation of Potassium Hydroxide by the Electrolysis of a Potassium Chloride Solution. Assemble an electrolyzer (see Fig. 130, p. 231). Place small cylinder 2 (8 cm in height and 4 cm in diameter) made from uncalcined clay into 0.5-litre thick-walled beaker 1. Pour a saturated potassium chloride solution into both vessels so that the level of the liquid in them will be the same. Add a few drops of phenolphthalein to the electrolyte. Use carbon rod 4 as the anode and thick iron wire 3 as the cathode. Secure both electrodes with corks in the electrolyzer lid. A d-c source at 10 V is needed for the experiment. After assembling the electrolyzer, switch on the current. What happens in the anode and cathode compartments Write the equations of the reactions. What substances can form in the absence of a diaphragm ... 

A representative catalytic reaction is described. TpRu(CO)(NCMe)(Ph) (0.021 g, 0.046 mmol) was dissolved in 4.1 mL (0.0456 mol) distilled benzene and decane (0.269 mL, 1.38 mmol) was added to the homogeneous solution as internal standard. The solution was placed in a thick-walled glass reaction vessel and charged with 25 psig ethylene. The tube was then placed in an oil bath heated to 90 °C. Periodically the tube was removed from the oil bath and plunged into an ice bath. A sample (0.1 mL) of the reaction solution was removed under a purge of dinitrogen and the tube was quickly returned to the oil bath and ethylene pressure was restored. The removed samples ( 1 (iL) were analyzed by GC-FID. 

Fig. 1. Illustration of tube-in-tube-in-tube reaction vessels applicable for high-temperature sulfide experimentation. The inner reaction vessel (A) is 2 to 4 mm l.D. (wall thickness 1 mm) with a total length not exceeding 25 to 30 mm. The dimensions of the closely fitting second tube and the outside vessel are consequently larger...

Caution Azides can be explosive (see above). l//-Pentafluoroprop-l-ene (26 13.2 g, 0.10 mol) was condensed in vacuo into a cold ( — 196 C). thick-walled, 300 raL-Pyrex tube containing NaN 3 (13.0 g, 0.20 mol) and DMF (120 mL). The tube was sealed in vacuo and placed in a stout, mild steel guard tube while still cold. The guard tube was stored at rt for 17d. during which time it was frequently shaken gently. The volatile product was pumped from the reaction vessel, condensed at - 196 C. and fractionated in vacuo to give unrcacted 26 (0.8 g, 6.1 mmol, 6% recovery) and the desired product 27 yield 4.1 g (26mmol. 28 % based on amount of 26 consumed). 

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