Glass tanks

Wall losses through most refractory walls are ca 10% of the heat suppHed by the fuel. Losses increase with rising operating temperature. In special cases, eg, in glass tanks, losses can be as high as 30—35%. In these instances, very high values are requked to maintain the refractory at a temperature below which it does not melt or coUapse. 

Fusion-Cast Shapes. Refractory compositions are arc-melted and cast into shapes, eg, glass-tank flux blocks as large as 305 X 610 X 1219 mm. After casting and annealing, the blocks are accurately diamond ground to ensure a precise fit. 

Forsterite Refractories. Refractories made from forsterite, Mg2Si04, resist alkah attack and have good volume stabiUty, high temperature strength, and fak resistance to basic slags. Uses include nonferrous metal furnace roofs and glass-tank refractories not in contact with the melt, ie, checkers, ports, and uptakes. 

As a result of the larger flues and the restric ted surface area per unit of gas passed, regenerators employed with this type of furnace exhibit much lower efficiency than would be reahzed with smaller flues. In view of the large amount of iron oxide contained in open-hearth exhaust gas and the alkah fume present in glass-tank stack gases, however, smaller checkerbrick dimensions are considered imprac tical. 

Sihca bricks are used extensively in coke ovens, the roofs and walls of open-hearth furnaces, and the roofs and sidewalls of glass tanks and as linings of acid electric steel furnaces. Although sihca brick is readily spalled (cracked by a temperature change) below red heat, it is very stable if the temperature is kept above this range and for this reason... 

The Morris (1984) water maze is a large circular glass tank (1.5m diameter) filled with opaque (e.g. dye-treated) water to a depth of some 50 cm. A small platform, large enough to take the rat, is placed in the water with its top about 1.5 cm below the surface, so it cannot be seen. When placed in the water the rat finds and escapes to the platform, the position of which is apparently learnt by reference to peripheral visual markers. Memory is demonstrated by the rat s ability to swim to the platform when put back into the water at various points and measured by the time or the length of path taken to do so (Fig. 18.3). 

Chromatographic development chambers for analytical pirrposes are commercially available in several different sizes. The most commonly used ones are rectangiflar glass tanks with inner dimensions of 21 X21 X9 cm, and they can be used to develop two plates simultaneously in the preparative scale. Even bigger tanks are available for much larger plates, for preparative layer chromatography. The width of the chamber should be varied depending on the size and the number of plates to be developed. 

Silica bricks are used extensively in coke ovens, the roofs and walls of open-hearth furnaces, and the roofs and sidewalls of glass tanks and... 

Other types of refractory that find use are forsterite, zirconia, and zircon. Acid-resisting bricks consisting of a dense body like stoneware are used for lining tanks and conduits in the chemical industry. Carbon blocks are used as linings for the crucibles of blast furnaces, very extensively in a number of countries and to a limited extent in the United States. Fusion-cast bricks of mullite or alumina are largely used to line glass tanks. 

Material required Seedlings of each test plant species, plastic dishes (200 ml), glass tanks (35x35x25 cm), fresh A. ursinum leaves or A. ursinum bulbs (50 g). 

A stable atmosphere saturated with the vapour of the mobile phase is required to ensure reproducible Rt values. Unless saturation conditions prevail, solvent will evaporate from the surface of the thin layer causing an increased solvent flow but slower movement of the solvent front f f values consequently increase. In practice, chromatograms are best developed in a sealed glass tank in which a saturated atmosphere has been produced by... 

Tilapia fish (25-35 mm length) were selected as the test organisms because of their ability to live in adverse conditions. Five juvenile fish were acclimated in a glass tank containing 2 liters of clean, conditioned water. The extract was mixed with the water in the experimental medium. The tanks were not aerated nor the fish fed during the 24-hr test. Bioassays of the organic solvent extracts were performed at a concentration of 0.1 ppt. 

Zirconia Refractories. The most common zirconia-containing refractories are made from zircon sand and are used mosdy for container glass-tank subpaver brick. Refractory blocks made from a composition of zircon and alumina, used to contain glass melts, are generally electromelted and then cast. These exhibit excellent corrosion resistance but are subject to thermal shock. Refractories made from pure Zr02 are extremely expensive and are... 

A similar system of checkerwork regenerators is used in connection with glass-tank heat-storage systems,... 

Blast furnace gases, brick kilns, annealing furnaces, boilers, acid production, reactors, superheater tubes, nuclear pile instrumentation, soaking pits, glass tank flues. 

Development of plates. Individual 20 x 5 cm plates are conveniently developed in a cylindrical glass jar (Fig. 2.133) (Shandon). Larger plates, 20 x 10cm and 20 x 20 cm, require a rectangular glass tank of suitable dimensions such as that shown in Fig. 2.134 such a tank can also be used to allow the simultaneous de-... 

A modular continuously stirred glass tank reactor (from Cole-Parmer, Inc., USA) with an effective volume of 2 L was used in the OTASP. Peristaltic pumps were used at the inlet and at the exit of the reactor for feed/harvest, respectively. Aeration and efficient mixing was provided in the reactor temperature and pH were controlled at 25 1 ° C and 7 0.01, respectively, by electronic controllers. A synthetic wastewater with known inlet substrate concentration (in terms of... 

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