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Vacuum systems liquid-ring pumps

A useful summary of the typical equipment used for developing and maintaining process system vacuum is presented in Table 6-1. Also see Birgenheier [33]. The positive displacement type vacuum pumps can handle an overload in capacity and still maintain essentially the same pressure (vacuum), while the ejectors are much more limited in this performance and cannot maintain the vacuum. The liquid ring unit is more like the positive displacement pump, but it does develop increased suction pressure (higher vacuum) when the inlet load is increased at tlie lower end of the pressure performance curve. The shapes of these performance curves is important in evaluating the system flexibility. See later discussion. [Pg.344]

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,... [Pg.630]

The vacuum system can be equipped with steam ejectors or with liquid ring pumps (vacuum pumps), or a combination. [Pg.299]

Fig. 2 Liquid ring vacuum system with closed pump fluid circuit, Dr.-Ing. K. Busch GmbH... Fig. 2 Liquid ring vacuum system with closed pump fluid circuit, Dr.-Ing. K. Busch GmbH...
These two vacuum systems can be compared on an annualized basis as discussed in Section 17.4, but it seems clear that the higher cost of the liquid-ring pump is more than offset by the much higher utility cost to operate the ejector system. The screw compressor is also a candidate, but its purchase cost, 65,000, is significantly higher and the annual electricity cost, at an overall efficiency of 70%, is only about 1,700/yr less than for the liquid-ring pump. ... [Pg.557]

Section 12.6.3 discusses the various methods of pressure control in vacuum systems. It points out that some situations, more common with liquid-ring pumps than with steam jets, favor allowing atmospheric air to enter the process. This balances capacity and demand. The chlorine recovered here, however, may be combined with the cell gas and processed through liquefaction. In that case, the air added to the system reduces the efficiency of liquefaction (Section 9.1.7.2A). Pressure control by recycling some of the compressed vapor to the vacuum producer then would be a better method. [Pg.672]

There is no vacuum source that is the best choice for every application. The technology for protecting mechanical pumps from process upsets and abuse is highly developed. This technology can be used effectively in designed vacuum systems to meet specific requirements. In several applications, mechanical pumps have demonstreted reliability comparable with, or superior to, liquid-ring pumps or steam jet ejectors. [Pg.240]

Dual-phase extraction cannot remediate heavy chlorinated compounds, pesticides, or heavy hydrocarbons including polychlorinated biphenyls (RGBs), dioxin, fuel oil No. 6, or metals (with the possible exception of mercury). High-velocity pump systems (such as liquid ring vacuum pumps) tend to form emulsions, especially when diesel fuel is part of the recovered fluids. The problem of emulsion can be solved with prepump separation or a de-emulsification unit. [Pg.505]

Noncondensable gas-removal system, to remove and compress the noncondensable gases. A typical system uses two stages of compression. The first stage is a steam jet ejector. The second stage is another steam jet ejector, a liquid ring vacuum pump, or a centrifugal compressor. [Pg.1180]

The vacuum at the top of the flash column is often produced by a sequence of three elevated steam-jet eductors with intermediate and final surface condensers to remove the steam. A liquid-ring compressor can be substituted for one or more eductors to conserve steam. Mechanical vacuum pumps are seldom used because of the corrosive nature of the off-gas. The noncondensible sour compressed gas and condensate are led away through a water seal for safety in case of steam system failure. The seal pot is equipped to skim off condensed oil continuously. [Pg.2062]

The chemical plant consists of a single-effect vacuum evaporator system for regenerating the solution and liberating the sulfur dioxide. Indirect heat is supplied to the forced-circulation evaporator by using exhaust steam from the refinery. The vacuum is supplied by a liquid ring vacuum pump which also pumps the sulfur dioxide back into the front of the Claus plant. [Pg.168]

In general, liquid ring vacuum systems are operated with simple particle separators on the intake side. The idea is to have the vapour components separated out on the intake side, provided that this is a low-maintenance option, and controlled compression and condensing of the process vapours occurs in the vacuum pump. [Pg.311]

Vacuum systems with rotary vane vacuum pumps may be used where the process requires vacuums < 50 mbar or if liquid ring vacuum pumps cannot be used in the installation. These vacuum systems are designed to separate out as much of the process vapours and particles as possible on the intake side or to condense the process vapours into the atmosphere as moist air. Rotary vane vacuum pumps may be operated as recirculahng lubrication or blow-by vacuum pumps. The vacuum pump is built with a rotor turning eccentrically in a cylinder. The rotor has axial slots and rotating vanes are pressed against the cylinder by centrifugal force in these slots (Fig. 3). [Pg.312]


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See also in sourсe #XX -- [ Pg.1203 ]




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