Transfer processes in heterogeneous reduction reactors

Abstract

The results of experimental study are presented and mathematical models are proposed for heatand mass-transfer coefficients in a packed bed layer of reacting particles immersed in a liquid through which the reaction products are bubbled. It is shown that turbulence models based on taking into account the motion of bubbles, which rise under the action of buoyancy forces and set the liquid in swirling motion, quite adequately describe the transfer processes in gas-liquid systems, including the layer of dispersed particles.

Atmospheric corrosion of metals in regions of cold and extremely cold climate (a review)

“…The rate of steel corrosion at the Mirnyi station is comparable with (and that of copper even exceeds) that observed on the Aion Island and Apapel'khino Peninsula (Far East), where the Cl -concentrations amounted to 33.8 ad 20.1 mg/(m 2 day) and the TOW exceeds 1000 h/year [4,26] (the Far-East data were obtained using the dry-fabric method and recalculated to the wet-candle values [25,28]). However, if the TOW would be determined for T > -4 ° C, the corresponding value for the tests at Mirnyi would increase by a factor of more than 7 to reach 987 h/year (in the test period) [5].…”

“…Figure 5 shows a map of the Far East with the sites of atmospheric corrosion testing stations. Tables 12 and 13 present data on the positions of these stations, environmental conditions, and corrosion rates of carbon steel, zinc, copper, and aluminum [3,4]. For the comparison, Tale 13 also shows data for the sub-Arctic station (Northern Corrosion Station, NCS) on the Barents Sea coast at Murmansk (Dal'nie Zelentsy).…”

“…Only several corrosion testing programs involving investigations in under cold climate conditions have been completed so far, including Russian test programs on the Far East [3,4] and in Antarctica (Mirnyi station) [5], joint Norway-Russia Arctic program [5][6][7][8][9][10], Australian program of Antarctic tests carried on several stations (including intracontinental), Russian investigations on the Vostok station, American program at the Amundsen-Scott south-pole station [11,12], and corrosion tests on the northern stations of Norway, Sweden, and Canada according to their national and joint (Scandinavian) programs [13][14][15]. Corrosion tests at separate locations with cold climate were performed within the framework of ISOCORRAG program by the Technical Committee 156, which is involved in the development of international standards in atmospheric corrosion [16][17][18], and MICAT project [19][20][21].…”