Gauze supports

Into the 100-mL beaker place a smaller 50-mL beaker. Fill the smaller one halfway with ice cubes or ice chips. Place the assembled beakers on a wire gauze supported by a ring clamp (Fig. 15.5). 

Catalyst baskets and gauze supports (where the temperature may reach 900°C) must be resistant to oxidation, nitriding and distortion from high temperatures. Typical materials of construction are high strength alloys made of iron-nickel-chromium, nickel-chromium and nickel-chromium-tungsten-... 

Directions (a) Grind in a mortar about 2 grams of potassium iodide, add an equal volume of manganese dioxide and put the mixture in a crucible on a wire gauze supported on... 

In the distillation of substances of low volatility at atmospheric and reduced pressures a short column is all that is employed and its function is mainly to act as spray trap. Coarse packing, placed on a gauze support, is used plate columns are unsuited for such purposes. It is obvious that the column should be provided with a heating jacket and that no part of the apparatus, from the stiU pot to the condenser, should be unheated, so that there may be no partial condensation. The receivers should also be capable of being warmed. A useful measure is to heat the take-off valve by radiation from an infrared source or by a hot air blower (hair dryer), so as to prevent it from sticking. Better still is the use of magnetic valves. 

The eatalytie oxidation of ammonia is earried out at 1-10 atm and temperatures of 850 950°C in adiabatie reaetors up to 6 m in diameter. The reaetor has a double-eone shape, with the gauzes supported at the middle. For operation at 1 atm, only four or live gauzes are needed, but up to 30 are used for high-pressure operation. Even with 30 gauzes, the bed is less than 1 em thiek, and the gas residenee time is only a few milliseeonds. 

The separator has traditionally been asbestos, often with a nickel gauze support. It should be remembered that the only role of the separator in a water electrolyser is to keep the gaseous products apart. It was noted above that the equilibrium potential for the cells is —1.23 V. In fact, no discernible gas evolution is observed until the cell voltage is from —1.65 to —1.79 V, and for the operating current densities of 100-600 mA cm the cell voltage is generally... 

Adiabatic gauzes Layers of gauze supported on a large open mesh. Usually a high anabatic temperature rise through the gauzes. 

Catalyst gauze supported on high-chrome steel mesh. Burners can be operated at absorber pressure in lOP/POP plants. 

Transfer the solution into the flask, add some unglazed porcelain, and support the flask over an asbestos-covered gauze. Heat the solution cautiouslv with a Bunsen flame so that the temperature... 

Filter the dried product through a fluted filter paper or a small cotton wool plug supported in a funnel into a dry 50 ml. distilling flask, and distil on a wire gauze or from an air bath (Fig. 11, 5, 3). Collect the fraction, b.p. 100-103°. The yield of n-butyl bromide is 18-19 g. 

Place 50 g. (57 ml.) of dry A.R. benzene and 0 5 ml. of dry p rridine (1) (dried over potassium hydroxide pellets) in a 500 ml. round-bottomed flask. Attach a reflux condenser to the flask and an inverted funnel (just dipping into some water in a beaker) to the top of the condenser (Fig. II, 13, 8, b). Partially immerse the flask in a bath of cold water, supported upon a tripod and gauze. Carefully pour 125 g, (40 ml.) of bromine (for precautions to be taken with bromine, see Section 111,35, Note 1) through a condenser and immediately insert the absorption device into the upper end of the condenser. A vigorous reaction soon occurs and hydrogen bromide is evolved which is absorbed by the water in the beaker when the reaction slackens, warm the bath to 25-30° for... 

Catalytic properties are dependent on physical form, principally the exposed surface area which is a function of particle size. Industrial PGM catalysts are in the form of finely divided powder, wine, or gauze, or supported on substrates such as carbon or alumina (see Catalysis Catalysts, supported). 

In the presence of metallic copper, metallic silver, or a copper-silver alloy used in the form of gauze or as metal deposited on a low surface area inert support, methanol can be dehydrogenated to formaldehyde at 400—500°C. 

Should be distd under reduced pressure under nitrogen and stored in the dark. Purified via the nitrosochloride [Waterman et al. Reel Trav Chim Pays-Bas 48 1191 7929]. For purification of optically active forms see Lynn [J Am Chem Sac 91 361 1919]. Small quantities (0.5mL) have been purified by GLC using helium as carrier gas and a column at 90 packed with 20 wt% of polypropylene sebacate on a Chromosorb support. Larger quantities were fractionally distd under reduced pressure in a column packed with stainless steel gauze spirals. Material could be dried with CaH2 or sodium, and stored in a refrigerator CaS04 and silica gel were not satisfactory because they induced spontaneous isomerisation. [Bates, Best and Williams 7 C/iem Soc 1521 7962.]... 

Typical conditions would be to pass a mixture of SO2 and air over Pt gauze or more commonly a V20,s/K20 contact catalyst. supported on Kiesel-guhr or zeolite. 

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