Vacuum systems equipment

The ionic current intensity corresponding to the peak at 169 amu was analyzed under isothermal and polythermal conditions [383]. It was found that in a gaseous atmosphere, the intensity changes are in correlation with the CO content and in negative correlation with the C02 content. The presence of CO in vacuum systems equipped with heating elements is usually related to thermo-cycling and desorption of CO by nickel atoms [386]. Based on the above, the presence of NbF4+ ions in mass spectra is most probably related to the niobium reduction process, which can be represented as follows ... 

The gases can be introduced into the vessel by the use of an all-metal system or a Kel-F lubricated-glass vacuum system equipped with a fluorine-resistant pressure gagef and a soda-lime trap to protect the vacuum pump. The author s preference for an overall system is the all-metal transfer line and the reaction... 

The vacuum line used in this synthesis is a standard, calibrated, high vacuum system equipped with a two stage mechanical forepump and a dual stage mercury diffusion pump. The operation pressure in this system is 10 torr or lower. ... 

The apparatus shown in Fig. 1 is constructed from Pyrex glass and attached to a standard vacuum system equipped with a mechanical oil pump and mercury vapor diffusion pump. A detachable trap cooled in liquid nitrogen is inserted between the apparatus and the vacuum system so that any volatile condensible material escaping from the reactors during the experiment can be collected and weighed. 

Hydrogen volumetric adsorption measurements were carried out in a conventional high vacuum system equipped with a capacitance gauge, MKS Baratron, model 220 BHS. The time spent between succesive isotherm points was routinely 20 minutes. The final hydrogen pressure was 300 Torr. 

The group of Nishimura has evaporated 100 nm thick films of palladium onto both sides of foils of vanadium alloyed with nickel, aluminum and molybdenum in an ultra-high vacuum system equipped for physical vapor deposition [62-66]. 

Towers, columns- trayed/packed Vacuum system equipment Vessels- pressure, storage Crushers.flakers.mills.stock Evaporators, dryers, cryst. 

Vacuum systems, largely for the semiconductor industry, are the main source of sales (see Semiconductors). The sales of all vacuum equipment, pumps (qv), valves, sensors (qv), etc, in the United States, including apphcations not in vacuum systems, generally exceed 500 X 10 /yr. A reasonably comprehensive hst of high vacuum manufacturers is supphed by the American Vacuum Society s exhibitor s hst. In Europe, a special issue of the journal A acuum serves similady. 

Batch distillation equipment can range from a free-standing column with a reboiler, condenser, receiver, and vacuum system, to the use of a jacketed reactor with a condenser. Distillation often involves the generation of combustible vapors in the process equipment. This necessitates the containment of the vapor within the equipment, and the exclusion of air from the equipment, to prevent the formation of combustible mixtures that could lead to fire or explosion. 

In quadrupole-based SIMS instruments, mass separation is achieved by passing the secondary ions down a path surrounded by four rods excited with various AC and DC voltages. Different sets of AC and DC conditions are used to direct the flight path of the selected secondary ions into the detector. The primary advantage of this kind of spectrometer is the high speed at which they can switch from peak to peak and their ability to perform analysis of dielectric thin films and bulk insulators. The ability of the quadrupole to switch rapidly between mass peaks enables acquisition of depth profiles with more data points per depth, which improves depth resolution. Additionally, most quadrupole-based SIMS instruments are equipped with enhanced vacuum systems, reducing the detrimental contribution of residual atmospheric species to the mass spectrum. 

Figure 2-47. Acceptable pressure losses between the vacuum vessel and the vacuum pump. Note reference sections on figure to system diagram to illustrate the sectional type hook-ups for connecting lines. Use 60% of the pressure loss read as acceptable loss for the system from process to vacuum pump, for initial estimate. P = pressure drop (torr) of line in question Po = operating pressure of vacuum process equipment, absolute, torr. By permission, Ryans, J. L. and Roper, D. L., Process Vacuum System Design Operation, McGraw-Hill Book Co., Inc., 1986 [18].

Estimated Air Leakage Into Equipment Vacuum System... 

The burner and associated equipment must be wrapped up or otherwise protected against dirt and soot. The front doors are opened and plastic sheeting is attached to minimize the spread of soot. The tubes are brushed, and the soot and dirt are vacuumed away while brushing takes place. Some contractors have truck-mounted vacuum systems to increase efficiency and minimize post-boiler cleaning work. 

A 300-mL three-necked flask is equipped with a mechanical stirrer and a reflux condenser connected to a vacuum system through a cold trap. 

The possibility to grow good-quality thin films at room temperature and normal pressure is the main advantage of SILAR relative to the gas-phase techniques. Moreover, since vacuum systems are not required, SILAR deposition equipment is simple and inexpensive. Similarly, toxic chemicals, such as selenium compounds, which are easier and safer to handle as solutions than as gases, can be more conveniently employed in SILAR. From the environmental point of view, a notable advantage of SILAR is that the system is totally closed and all the chemicals that are used are recyclable. Compared with other solution-phase methods, especially with CBD, an important advantage of SILAR is the facile control over film thickness using... 

The advent of a new class of materials systems based on nanoscale particles dispersed or suspended in carrier and/or binders has captured the attention of the microelectronics technical community. These materials provide the opportunity to use inexpensive solution processing equipment versus expensive vacuum deposition equipment commonly used in the microelectronics manufacturing industry. Experts in the microelectronics industry have suggested that over the course of the next live years, the industry will experience a paradigm shift in manufacturing and, more importantly, will enjoy revenue streams created from never-before-seen products based on printed electronics. 

Alternatively, vacuum within equipment could lead to ingress of air into inerted or fuel-rich systems, posing a fire or explosion hazard within the equipment. 

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