Eductor vacuum

After another review of the practical constraints and technical considerations, it was concluded that an eductor vacuum-enhanced recovery system would be feasible and still be cost-effective and efficient. In all, 11 6-in.-diameter wells extending to a depth of 28 ft were installed at strategic locations in the area where product seeps were observed. Each well was serviced by a high-pressure supply and a low-pressure return line. A basic domestic-type deep-well eductor was installed in each well, attached to a drop pipe that extended to 25 ft below the surface. A check valve on the drop pipe prevented backflow into the well during service. The top of the casing... 

The control system is designed to sense certain component and system failures. Pressure switches are located to sense overpressure, excessive suction, low chlorine pressure, and low eductor vacuum. A flow switch senses low flow. Motor starters sense motor overloading. Evaporator low-temperature switch senses low water temperature. 

Chlorine Gas—Sodium Chlorite System. In this method, chlorine gas reacts direcdy with a concentrated sodium chlorite solution under a vacuum and chlorine dioxide gas is removed from the reaction chamber using a water-based eductor (117). The reaction has a 100% theoretical molar conversion of chlorite ... 

Multistage porous diffuser contactors, which involve a single application of an ozone-rich gas stream and application of fresh ozone gas to second and subsequent stages with off-gases recycled to the first stage. Eductor-induced, ozone vacuum injector contactors, which include total... 

Steam jet syphons Steam jet slurry heater Single-stage vacuum pumps Using air as the motive fluid Air jet exhausters Using liquid as the motive fluid Water jet eductors... 

Incoming water is sprayed through a packed column, which provides for an enlarged surface area, and aids the release of gases from the thin film of water produced in the packing. Depending on the DA size and design, the applied vacuum is maintained either by vacuum pumps or by stream-jet eductors. 

This chapter primarily deals with vacuum jets (eductors) and vacuum systems associated with vacuum fractionators. The design of vacuum overhead condensers is discussed in Chapter 7. 

Barometric condenser systems can be a major source of contamination in plant effluents and can cause a particularly difficult problem by producing a high-volume, dilute waste stream [8]. Water reduction can be achieved by replacing barometric condensers with surface condensers. Vacuum pumps can replace steam jet eductors. Reboilers can be used instead of live steam reactor and floor washwater, surface runoff, scrubber effluents, and vacuum seal water can be reused. 

A column vacuum was produced with the eductor, and the operating pressure set to the desired test conditions. Water and steam flows were initiated, and the column was allowed to reach steady state. Steady state was determined by careful monitoring of column temperatures at the reboiler, mid-column, and top of column and confirmed by analysis of vapor and liquid samples drawn from the column sample ports over a 2- to 3-hour period. The height of an equivalent theoretical plate (HETF) of the packing was 19 in., as calculated from vapor and liquid sample compositions. 

The preferred transfer mechanism uses the potential energy of pressure or gravity. If the transfer operation is critical, then system reliability is highly important, and the transfer mechanism should be fail-safe. Where time allows, pumps, compressors, or an eductor or vacuum system can be used. 

Tank fabricators and tank inspectors check new and repaired welds on floors of low-pressure tanks using soap suds. They commonly use a vacuum box to check tank floor seams. The inspection team coats a short section of weld seam with soapy water. An inspector places a custom-built rectangular box that has a clear window on the top of the soapy weld seam. A specially designed air eductor, which uses compressed air, evacuates the box. If soap bubbles appear in the box, the inspector marks the defective weld for repairs. 

For a condenser operating at atmospheric pressure, an adequate vent is all that is necessary. However, air is often not suitable for contact with the process due to concern about contamination or flammability. In these cases, the vent may be connected to a source of low pressure nitrogen, or other inert gas. For vacuum operation, the vent must also be connected to a vacuum pump or steam jet (eductor), as shown in Figure 3.11(B). The pressure controller adjusts the split range control valves such that as its output decreases, first PV-2 closes then PV-1 opens. Normal operation would... 

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. 

Eductor An in-line static mixing device that, by flow of water through it creates a vacuum, thereby drawing a solution into the water stream. 

To protect a metallic pipeline from corrosion, the brine should first be deaerated. Drawing a vacuum is the most convenient technique (Section 12.6). If the source of brine is remote, there may be no steam available to drive an ejector. A vacuum pump may then be used, or an eductor driven by brine or air. Typical operating pressures for deaeration are 10-20kPa. 

The eductor or eductor-jet pump is also called an injector, a vacuum ejector, a water eductor, a steam-jet ejector, or an aspirator. Every chemistry laboratory has rrtany. 

An eductor would be an excellent choice for the vacuum pump in an enclosed machine where the parts are badly soiled with large or abrasive particulate matter, or mobile gelatinous or viscous material. This is because there are no clearances to be fouled in an eduaor and the liquid... 

For the performance data of steam-driven eductors, see Foisy, E.C. and Munkittrick, M.T., "Energy Comparison Vacuum Producing Equipment Mechanical Vacuum Pumps Vs. Steam Ejectors," Proceedings from the Fourth Industrial Energy Technology Conference Houston, TX, April 4 7,1982. 

Note the dependence of pressure change on circular channel diameter (D), all else being the same. It s to the fourth power That dependence is how one can design an air amplifier with a large diameter venturi and expect only a small pressure change sufficient to entrain additional air relative to an eductor with a small diameter venturi which would produce a substantial pressure change — a partial vacuum upstream. 

Vacuum eductor. Often this vacuum generator, usually a venturi, is installed on the panel and used during purge sequences. 

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