Phase space compressor

This is just what has been done with Ag2. A sputtering source followed by a phase-space compressor chamber provided a beam of cooled negative cluster ions of many sizes. From these, the dimers were selected, accumulated in a quadrupole trap, and photodetached with a femtosecond, titanium-sapphire laser. After photodetachment by a 60-fs pulse, the neutral dimers oscillate, causing corresponding oscillations in the ionization cross section, in turn generating the oscillations that dominate the intensity pattern in Fig. 11. This is a simple phenomenon, yielding in a simple way the... 

Feedstocks which can be completely vaporized, can be treated in gas phase processes. At the conditions prevailing in the reactor (250 0-300 bar), several hundreds mol of hydrogen must be fed per mol of ester and, sometimes, methanol is needed to dilute the gas stream and to decrease the ester partial pressure. The energy necessary to drive the recycle compressor is therefore very important. The liquid space velocity is c. 0.35 hr . The absence of liquid in the reactor enables to use an unsupported catalyst of high activity. This catalyst is a promoted copper oxide which is very resistant to poisoning. The consumption of catalyst is less than 0.3. This catalyst is very pyrophoric it must be reduced inside the reactor. As the amount of catalyst per unit volume of reactor is higher than in slurries, the selectivity is also higher it can reach 9 Plants of 12000 t/a capacity have been built. 

Positive displacement blowers Positive displacement blowers are probably the most commonly used type of compressor for dilute phase conveying systems. They provide an ideal match, in terms of pressure capability, with the conventional low pressure rotary valve, and are a typical working combination on many plants. They can be used as vacuum pumps, or exhausters, as well as blowers. The principle of operation is illustrated in Figure 4.26. Twin rotors are mounted on parallel shafts within a casing, and they rotate in opposite directions. As the rotors turn, air is drawn into the spaces between the rotors and the casing wall, and is transported from the inlet to the outlet without compression. As the outlet port is reached, compression takes place when the air in the delivery pressure pipe flows back and meets the trapped air. 

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