Small ceramic rings

The ion entrance plate ( 0.1 mm thick) with a small hole (typically 0.5 mm diameter) has the same electric potential as the copper cell, whereas the exit plate (same dimensions) is mounted to a cell end cap that is electrically isolated from the cell body by a ceramic ring. The end cap has its own cooling and heating systems. 

To facilitate removal of water vapor, a small amount of inert gas (e.g., nitrogen, argon, or helium) heated electrically to 20 C-30°C is injected into the bed of dried granules. The gas stream is fed to the lower chamber through a porous metal-ceramic ring embedded in the chamber wall just above the screw conveyor. The evaporated moisture is removed from the inert gas in two alternately operated condensers [88]. Although the basic model of the dryer is designed for liquid feeds, semisolid materials such as... 

There are a number of studies and monographs available on the subject of designing packed columns. However, these are restricted to the empirical presentation of design documents, mostly for small ceramic Raschig rings, spheres or Berl saddles and occasionally for Pall rings or Bialecki rings made of metal [ 10,16,21 ]. 

Fig. 2. Gas-fired denitration pots for denitration of U02(N02)2 6H20. (a) The large pot (1.68 M ID, 0.81 m height) is heated by three concentric rings of small radiant gas burners, (b) The small pot (76 cm ID, 46 cm height) is heated by four gas burners iaside a ceramic furnace (40).

Figures 9.1-9.3 illustrate these interconnected relationships.13 Figure 9.1 defines some of the terms used in this chapter. Small molecules are species with molecular weights below about 1,000. They are volatile at temperatures below say 200 100 °C. Clusters are oligomers derived from covalently linked small molecules. They have a lower volatility than small molecules and, if large enough, can be shaped by melting or by solvent evaporation methods. Linear polymers can be simple chain structures or may consist of rings linked together. In either case they are usually non-volatile and easily fabricated. Cross-linked systems can be produced from polymers or from clusters. The final ceramic may be amorphous or crystalline.

A 1500-W tubular heater is wrapped around the reactor. The autoclave is placed inside a copper pipe, with Fiberfrax bulk fiber insulation packed between the copper pipe and the reactor. Four 1000-W quarter-circle ceramic heaters are placed around the copper pipe. The space between the copper pipe and the ceramic heaters is filled with aluminum balls for efficient and uniform heat transfer from the heaters to the copper pipe. The bottom of the copper vessel is closed with a copper plate. Beneath the copper plate, there are two heaters (a small one of 500 W and a larger one of 1000 W), which are tightly clamped to the bottom copper plate. The top of the copper pipe is similarly covered with another copper plate, and two slots are provided for the feed and product gas lines, coolant inlet and outlet lines, thermocouple extension wires, and the lead wires of the tubular heater. Two ring heaters (660 and 1000 W) are placed on the top copper plate. One thermocouple and a tape heater are placed on the shaft extension to minimize the heat loss through the shaft. No insulation is placed around the ceramic heaters to achieve better control of... 

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