Vacuum equipment Pumps

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. 

For around 20 years now, numerous standards and recommendations have been drawn up at national and international level and revised, whenever necessary, in accordance with the state of the art. These standards and recommendations must be observed whenever use is made of vacuum equipment (pumps, gauges, valves, etc.) and vacuum apparatus, systems and plants are assembled. They not only contain specifications applying specially to vacuum technology, but also go beyond this specific field and involve, for example, physical units, formulas, noise protection regulations, etc. 

Figure 3.6a shows how costs for a new distillation system vary with the reflux ratio. It expresses the capital cost as an annual cost. This can be achieved hy dividing the capital cost by the expected payout period. A discounted cash flow (DCF) analysis is used for estimating this payout period. The capital cost shonld include the costs of auxiliaries (reboiler, condenser, vacuum equipment, pumps, piping in many cases, costs of vent systems, coolant, and heating medium handling equipment are also affected). The operating costs should include reboiler... 

Vacuum equipment requires strength to withstand the pressure of the surrounding atmosphere. The full load is ca 101.3 kPa when the internal gas pressure in the system is sufficiently reduced (see Pumps). 

Lubricating and seal oil systems cleaned Instrumentation and controls checked Preliminary operation of lubricating and seal oil systems Operation with air Vacuum Equipment Alignment run-in testing Pumps... 

Saug-luft, /. vacuum, suction inlet air. -luft-anlage, /. vacuum equipment or plant, -liifter, m. exhauster, -luftkessel, m. vacuum vessel, -maschine, /. exhauster aspirator, -messer, m. vacuometer. -nkpfchen, n. suction cup. -papier, n. absorbent paper, -pipette, /. suction pipet(te). -pumpe, /. suction pump, -raum, m. suction chamber, -rohr, n., -rohre,/. suction tube or pipe, sucking pip siphon Venturi tube, -rdhrehen,... 

When the steam leaves a condensing turbine, it passes to a surface-type condenser for recovery of the condensate. Vacuum equipment (jets or pumps) are necessary to achieve high vacuums on the condenser. 

The manufacturer must know if the suction side of the pump is associated with vacuum equipment, or is to lift the liquid. This can make a difference as to the type of impeller suction opening he provides. If the system operates intermittently it should be noted. A piping diagram is often helpful in obtaining full benefit of the manufacturer s special knowledge. 

Vacuum capacities and operating ranges, table, 344, 355 Ejectors, 344, 357 Integrated systems, 344 Liquid ring pumps, 344 Rotary lobe blowers, 344 Rotary piston pumps, 344 Rotary vane pumps, 344 Vacuum equipment, 343 Applications diagram, 352 ASME Code, 344 Pumps, 382 Steam jets, 357 Vacuum flow,... 

In general, demountable joints In metallic vacuum components, pumps, valves, tubulatlons, and so on are provided with flanges. Vacuum components for rough, medium, and high vacuum from LEYBOLD are equipped with the following standardized flange systems ... 

If the desired ultimate pressure is not reached at all in vacuum equipment or if it is attained only after an excessively long pumping period, then the following problems may be the reason ... 

Equipment. At the time of publication of Ref 1 (1931), there were two Bichel Closed Bombs at BurMines, each of them made of strong cast steel. The No 1 apparatus had an interior capacity of 15 liters,. while the No 2 was of 20 liters. Their walls were 12.5cm thick. The heads of their cylinders were provided with lead gaskets, which were secured in pLace by 12 heavy stud bolts and aa iron yoke. For exhausting the air there was a tube inserted in a hole bored in an upper segment of each cylinder (See Fig on p C332-L of Vol 3 of Encycl), near one end. Exhaust tuhe of each cylinder was connected with a rotary, vacuum-air pump, driven by a 2-HP motor and provided with a valve which excluded the outside air after the desired vacuum was reached (usually 50li5ram of Hg). 

Vacuum Pumps. The function of these pumps is to evacuate the drying chamber quickly without allowing the prefrozen material to melt—and thereafter to reduce the pressure progressively to the desired vacuum and maintain it at Ihis level by removing the noncondensablc gases. The vacuum equipment can be cither an oil-sealed rotary vacuum pump, or a multistage stream-ejector system. 

Jet pumps are used to remove air, gases, or vapors from condensers and vacuum equipment, and the steam jets can be connected in series or parallel to handle larger amounts of gas or to develop a greater vacuum. The capacity of steam-jet ejectors is usually reported as pounds per hour instead of on a volume basis. Far design purposes, it is often necessary to make a rough estimate of die steam requirements for various ejector capacities and conditions. The data given in Table 3 can be used for this purpose. 

A. Pikulik and H. E. Diaz [Chem. Eng, 84, 106-122 (Oct. 10, 1977)] presented a graphical method for estimating the fabricated cost of distillation columns and pressure vessels, storage tanks, fired heaters, pumps and drivers, compressors and drivers, and vacuum equipment. 

Use Windows, structural building blocks, chemical reaction equipment, pumps and piping, vacuum tubes, lightbulbs, glass fibers, yams and fabrics, containers, optical equipment. Minute glass spheres with partial vacuum interior and treated exterior are available for compounding with resins for use in... 

The costs shown are plotted versus capacity, and cover the cost of the crystallizer and its ancillary equipment, including circulating pumps, circulating piping, vacuum equipment, con-... 

To reduce liquid-hydrogen boil-off, the explosion-containment vessel was evacuated to a pressure of about 25 fx. As a protection for the vacuum equipment two bursting discs (bursting pressure 70 psi) were installed between the vessel and the diffusion pump. 

Vacuum type c/s including vessel, pump, motor, drive and vacuum equipment. 

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