Other vacuum components

Even the simplest vacuum system like that of Fig. 1.5 consists of several separate components (vacuum vessel, pump, connecting pipe, detachable joints, valves, etc.) which are usually commercially available. 

Detachable joints are needed to assemble the various parts. They are made up of flanges pressed together with a gasket between. Among the commercial components, the three mostly used flanges for joints in vacuum technology are  

The choice of the type of joints to be used depends on the dimensions and on the requested vacuum level. 

In the first type (ISO-KF), the connections are made with conic profile flanges joined together by clamps, with an elastomer gasket (see Fig. 1.20). 

The standard dimensions for this type of flanges are from 10 to 50 mm of internal diameter (DN10-DN50). 

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For purposes of simplicity, in the case to be discussed, reactions involving sulfur, phosphorus, and other volatile components are assumed to be absent. Materials containing these elements must be avoided in vacuum systems which are to be used at high temperatures. The following reactions will be considered. 

Brass is basically a copper- zinc alloy bronze is a copper- tin alloy. In practice both often contain many other metals. Their high machinability, resistance to corrosion, and ease of soft soldering make them very useful in apparatus construction. Owing to the volatility of zinc, brass should not be used in vacuum components that must be baked out or operated hot. Certain bronzes such as phosphor bronze are useful for springs and diaphragms beryllium copper is also useful in these applications. 

Binder Cone. M0S2 %) Other Typical Components Cure Temp. °C Max.Temp. in air/ vacuum °C Wear Life Example... 

Derivatives of fatty acid from coconut oil are feedstock for a number of diverse nonfood products. Coconut oU fatty acids and glycerol are released by hydrolysis or alcoholysis of the fat. The fatty acids or their methyl esters, which are subsequently fractionated, constimte the starting materials for the oleochemical industry. The byproduct, glycerol, is purified by vacuum distillation. The purified product is, among others, a component of pharmaceutical preparations, an important ingredient in toothpastes, a raw material in the manufacture of nitroglycerol, and the fluid in hydraulic jacks and shock absorbers. 

In the measurement of vapor pressure, it is essential that the sample be thoroughly degassed even a small amount of dissolved air or other volatile component will distort the measurement. Degassing usually involves either distillation of the sample or placing the sample (sometimes after freezing) under vacuum. 

Energetic compounds can be collected for reuse by processing to reject binder, impurities, and other inert components. Explosives such as high-blast explosive (HBX), HMX, research department explosive (RDX, or hexahydro-l,3,5-trinitro-l,3,5-triazine), tetryl, TNT, NG, and NC are dissolved or suspended by steaming, high-pressure water jet cutting, or solvent extraction. Filtration, selective extraction/precipitation, vacuum evaporation, and other purification methods then separate the explosives from the binders and impurities, such as metal fragments and decomposition products. 

Work on the EDVAC was hindered after March 1946, however, when Eckert, Mauchly, and several other top engineers left the Moore School as a consequence of disputes about patent rights. The EDVAC was, nevertheless, finally completed in 1952. It stood 7 feet high, took up 500 square feet of floor area, and had more than 3500 vacuum tubes and 27,000 other electronic components. After its completion, the EDVAC was shipped to the Ballistic... 

The ability to concentrate yeast to high levels with CFF makes possible the recovery of beer from tank sediment (the so-called "gelager"), which is about 6 to 12% dry solids. In some countries, the tax on beer lost in this sediment is not refunded, so there is considerable economic incentive for recovery. Conventional processes, including yeast-presses, precoated vacuum filters and centrifuges, are not able to recover beer of good quality from this residue. Tubular MF is recommended for this application since UF membranes retain some of the proteins and other flavor components in the beer along with the yeast. 

Following the invention of the transistor, for many years, they were made as individual, discrete electronic components and were connected to other electronic components (resistors, capacitors, inductors, diodes, etc.) on printed circuit boards to make an electronic circuit. The transistor s small size and low power consumption made it an ideal candidate to replace the bulky vacuum tubes then used to amplify electrical signals and switch electrical currents. These beneficial attributes of transistors made it possible for them to be used in making ever more complex electronic circuits in place of vacuum tubes. However, it did not take long before the limits of this approach of building circuits were reached. Circuits... 

After the adhesive has been dispensed onto the PCBs or other interconnect substrate, bare die and other electronic components must be precisely placed. Of course, pick and place can be done manually using vacuum pick-up tools or tweezers, but this approach is useful only for small quantities, prototypes, or for rework. The risk of... 

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