Vacuum systems Diagrams

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].

Figure 6-33 diagrams vacuum system arrangements for process systems. It is important to examine the plant economics for each system plus the performance reliability for maintaining the desired vacuum for process control. 

Pressure/vacuum, 435, 466 Vacuum systems, 343 Absolute pressure conversions, 363 Air inleakage, 366 Calculations, 366-375 Dissolved gases release, 368 Estimated air inleakage, table, 366 Evacuation time, 371 Maximum air leakage, chart, 367 Specific air inleakage rates, 368 Temperature approach, 375 Classifications, 343 Diagrams, 380 Pressure drop, 353 Pressure levels, 343, 352 Pressure terminology, 348 Pump down example, 381 Pump down time, 380 Thermal efficiency, 384 Valve codes, 26... 

The phase diagram also illustrates why some substances which melt at normal pressure, will sublime at a lower pressure the line p = Pa intersects at Tg the locus OR of the points defining the solid-vapour equilibrium, i.e. at the pressure pj, the substance will sublime at the temperature T. Sometimes the opposite behaviour is observed, namely that a substance which sublimes at normal pressure will melt in a vacuum system under its own vapour pressure This is a non-equilibrium phenomenon and occurs if the substance is heated so rapidly that its vapour pressure rises above that of the triple point this happens quite frequently with aluminium bromide and with iodine. 

The experimental apparatus consists of eight main parts an ultraviolet flashlamp capable of repetitive flashing at about 5 Hz, a purge flow reactor with either pinhole or molecular beam sampling, an ion source, a mass filter, an ion detector, pulse-counting electronics, computer data aquisition, and a vacuum system. A diagram of the apparatus is shown in Figure 1. 

Figure 2.1 Schematic diagram of a basic vacuum system...

The high vacuum system shown below has a leak of 1 x 10-5 mbar L s-1. It has various ports (shown as 1, 2 and 3 in the diagram) where a leak detector can be connected. 

Figure 6.2 Schematic diagram of a vacuum system with a condenser between the vacuum vessel and the pump (1) vessel at working pressure p (2) condenser, coolant at T°C (3) vacuum pump (Seff at condenser outlet) (4) throttle valve (5) pressure controller...

Photochemical experiments were performed in a greasless glass high vacuum system of an ultimate °cuum of ca. 10 4 Pa. An schematic diagram of apparatus is shows in Fig.l. Powdered specimens of Ti02 (... 

An electrical diagram for a Pirani gauge is shown in Fig. 7.47, where V and D comprise the Pirani tube. D is the dummy filament tube that is sealed off, and V is the tube that is exposed to the vacuum system. The filaments in the V tube are connected to a bridge circuit called a Wheatstone bridge with two resistance units called Rj and R2. Power from the power supply passes across the Wheatstone bridge and is adjusted to the proper setting by R3, whose value is read on the mil-... 

Figure 6 shows a schematic diagram of the main components of the author s vacuum system. The furnace tube shown in Fig. 5 is attached... 

A schematic diagram of a vacuum system for liquid-solid surface chemical and electrochemical studies, including structural investigations, is shown in Fig. 1. The sample surface under investigation is shuttled back and forth between UHV and various solutions at ambient pressure without... 

Schematic diagrams of the apparatus, designed in our lab at< y, are shown in Fig. 1. Polymer flakes are placed, with a balls of about 5 mm dieter, in a glass an oule A about 4 cm in diameter and 7 cm in length. To the other end of the ampoule an ESR sample tube B is attached. Through connector C, the ampoule can be connected to a vacuum system and then evacuated to 10 mm Hg. After evacuation the connector is sealed off and the ampoule is removed from the vacuum system. The evacuated ampoule is now placed on a vibrator, wWch moves vertically at about 4 cycle per second. The procedure can be carried out in a Dewar flask containing coolant, such as liquid nitrogen, to fix the temperature. After some hours of this vibration, the crushed flakes are transferred to the ESR sample tube without raising the temperature of the sample. Ihen, sample tube containing the fractured flakes is placed in an ESR cavity at controlled temperature. The ball-mill apparatus permitted polymeric materials to be crushed in vacuum at low temperature and the ESR spectrum to be observed without contamination of oxygen.

Figure 24. Standard continuous vacuum bleaching system. (Diagram Courtesy LFC Lochem B. V.) (This figure is available in full color at http //www.mrw.interscience.wiley.com/biofp.)...

A block diagram of a typical molecular-mass spectrometer is shown in Figure 31-10. Sample molecules enter the mass spectrometer through an inlet system. In the case of GC, the sample is in the form of a vapor, and the inlet must interface between the atmospheric pressure GC system and the low-pressure (10 to 10 torn) mass spectrometer system. An elaborate vacuum system is needed to maintain the low pressure. In the mass spectrometer, sample molecules enter an ionization source, which ionizes the sample. The ionization sources for molecular mass spec-... 

The first technique for detecting properties of individual atoms on metallic surfaces was developed by Erwin Muller in 1936 (Chen 1993, 412). (For a history of this invention, see Drechsler 1978). This instrument, known as a field ion microscope, has a simple design comprising a vacuum system, a needle tip, and a phosphorescent screen. Muller s diagrams and discussion enable readers to visualize the technique he developed (Muller and Tsong 1969, 99) (Figure 1). 

Figure 14.26 Schematic diagram of an Auger spectrometer, showing the electron gun source, an electron flood gun and an ion gun, along with a carousel for multiple samples. The vacuum system is not shown. [Courtesy of Physical Electronics USA, Inc. Eden Prairie, MN (www.phi.com).]...

A schematic diagram of instrumentation used for ISS is shown in Fig. 14.36. This instrument is based on a CMA, discussed in Section 14.2.1.1. The instrument shown consists of an ion source, a vacuum system (not shown), an energy analyzer, and a detector. The major instrument components including the sample are under vacuum. 

Figure 9. Theory diagram of gas distribution and vacuum system.

A typical freeze dryer consists of a drying chamber, vacuum system, and vapor condenser, which can either be separated or built within the drying chamber. The drying chamber construction and the system of heat supply for sublimation can be solved in many ways. A schematic diagram of a continuous scraper-type freeze dryer especially suitable for biotechnological materials is presented in Figure 45.18... 

A block diagram of the present instrument is shown in Figure 3. The spectrometer consists of a cubic trapped-ion cell, a vacuum system (not shown), and the associated analog and digital electronics. The operation of the instrument is as follows the sample is introduced into the cell and is ionized by a short pulse from the electron beam. After a delay time that permits parent ions to react with the background neutral gas and form product ions, the cyclotron motion of all ions in the cell is coherently excited. This excitation is accom-... 

Figure 1 is a block diagram of a typical radio frequency plasma system. It consists of 5 modules or functions vacuum system, power supply, matching network, power monitor, reactor center, and controller. 

Figure 10.1 Conceptual diagram of a molecular beam scattering (MBS) experiment comprised of pulsed beam source, sample target, mass spectrometer detector, and a differentially pumped ultrahigh-vacuum system.

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