Fluid injector

H. L. T. Lee, P. Boccazzi, R. J. Ram, and A. J. Sinskey, Microbioreactor arrays with integrated mixers and fluid injectors for high-throughput experimentation with pH and dissolved oxygen control, Lab on A Chip, vol. 

The fluid injector is made from <100>-silicon and consists of a pump chamber with several in- and outlets A micro sieve with defined mesh size is used as a fluidic diode The outlet of the injector is separated from the micro sieve by an air space (see Fig 3 - left) so that in the off-state of the actuator the fluid 1 is kept totally decoupled from the carrier fluid 2 As to be seen in Fig 3 by computer-animation liquid-drops are injected to the carrier fluid without the carrier passes the sieve upward If the flow of the carrier is suppressed at the same time the injected drops will form a liquid volume below the sieve In this way, the fluid dosing can be performed without any leakage, even in the nl range The volume of the drop shown m Fig 3 (left) is about 1 5 nl The piezo-actuator (PZT-ceramic, 100 pm thick) is supplied with 30 100 V rectangular pulses The upper limit of the frequency is approximately 2 kHz... 

Ejectors and injectors are the two types of jet pumps of interest to chemical engineers. The ejector, also called the siphon, exhauster, or eductor, is designed for use in operations in which the head pumped against is low and is less than the head of the fluid used for pumping. 

The injector is a special type of jet pump, operated by steam and used for boiler feed and similar services, in which the fluid being pumped is discharged into a space under the same pressure as that of the steam being used to operate the injector. 

The efficiency of an ejecdor or jet pump is low, being only a few percent. The head developed by the ejector is also low except in special types. The device has the disadvantage of diluting the fluid pumped by mixing it with the pumping fluid. In steam injectors for boiler feed and similar seiwices in which the heat of the steam is recovered, efficiency is close to 100 percent. 

Figure 11-13. Reactors stirred by pumped fluid ID, Injector nozzle SK, float G, gas F, liquid. (Source Schuger [11].)...

Figure 12.22 SFC-GC analysis of aromatic fraction of a gasoline fuel, (a) SFC trace (b) GC ttace of the aromatic cut. SFC conditions four columns (4.6 mm i.d.) in series (silica, silver-loaded silica, cation-exchange silica, amino-silica) 50 °C 2850 psi CO2 mobile phase at 2.5 niL/min FID detection. GC conditions methyl silicone column (50 m X 0.2 mm i.d.) injector split ratio, 80 1 injector temperature, 250 °C earner gas helium temperature programmed, — 50 °C (8 min) to 320 °C at a rate of 5 °C/min FID detection. Reprinted from Journal of Liquid Chromatography, 5, P. A. Peaden and M. L. Lee, Supercritical fluid chromatography methods and principles , pp. 179-221, 1987, by courtesy of Marcel Dekker Inc.

Enhanced oil-recovery processes include chemical and gas floods, steam, combustion, and electric heating. Gas floods, including immiscible and miscible processes, are usually defined by injected fluids (carbon dioxide, flue gas, nitrogen, or hydrocarbon). Steam projects involve cyclic steam (huff and puff) or steam drive. Combustion technologies can be subdivided into those that autoignite and those that require a heat source at injectors [521]. 

Oil recovery can also be affected by extreme variations in rock permeability, such as when high-permeability thief zones between injectors and producers allow most of the injected drive fluid to channel quickly to producers, leaving oil in other zones relatively unrecovered. A need exists for a low-cost fluid that can be injected into such thief zones (from either injectors or producers) to reduce fluid mobility, thus diverting pressure energy into displacing oil from adjacent lower-permeability zones. 

The extracted fractions were esterified with either BF3-MeOH reagent or diazomethane and analyzed by GLC. Gas liquid chromatography (GLC) was conducted with a Perkin-Elmer Sigma 3 equipped with flame ionization detector. Separations were obtained on a Hewlett Packard 12 m x 0.2 mm i.d. capillary column coated with methyl silicon fluid (OV-101). The temperature was maintained at 80°C for 2 min then programmed from 80 to 220°C at 8°C/min. The injector temperature was 250°C. Mass spectra were obtained on a Hewlett Packard model 5995 GC-MS mass spectrometer, equipped with a 15 m fused silica capillary column coated with 5% phenyl methyl silicone fluid. Spectra were obtained for major peaks in the sample and compared with a library of spectra of authentic compounds. 

The basic SFC system comprises a mobile phase delivery system, an injector (as in HPLC), oven, restrictor, detector and a control/data system. In SFC the mobile phase is supplied to the LC pump where the pressure of the fluid is raised above the critical pressure. Pressure control is the primary variable in SFC. In SFC temperature is also important, but more as a supplementary parameter to pressure programming. Samples are introduced into the fluid stream via an LC injection valve and separated on a column placed in a GC oven thermostatted above the critical temperature of the mobile phase. A postcolumn restrictor ensures that the fluid is maintained above its critical pressure throughout the separation process. Detectors positioned either before or after the postcolumn restrictor monitor analytes eluting from the column. The key feature differentiating SFC from conventional techniques is the use of the significantly elevated pressure at the column outlet. This allows not only to use mobile phases that are either impossible or impractical under conventional LC and GC conditions but also to use more ordinary... 

Permanent utilization of the in-field Injectors may be detrimental in the long term as it affects the sustainability of the Marbel sector since it blocks the hot recharge towards this sector by creating a fluid barrier. 

A high-speed injector is required in supercritical fluid chromatography. This is to prevent loss of pressure during the injection process. 

The second device comprised a set of three circumferentially located pintle-type injectors Keihin, 10450-PG7-0031) to inject fuel radially into the main duct of the first flow arrangement as near-rectangular pulses. The frequency and duration of fuel injection were software controlled, and the fuel flow from each injector was delivered close to the outer edge of the annular ring flame holder by a cross-jet of air (1.2 x 5 mm), directed along the duct axis with exit velocity up to 100 m/s. The amplitude of the oscillated input was limited by the volume injection rate of the injectors. Propane, rather than methane, provided up to 3.5 kW of the total heat release of around 100 kW. With fluid dynamic damping, the RMS of the oscillated fuel flow corresponded to a heat release of around 1.8 kW. 

Evenly distributed across pipe multiple injectors, a flash of light on photosensitive fluid... 

Devices which are used for transporting fluids (liquids and gases) may be divided into pumps, ejectors, injectors, elevators, conveyors, air and gas pressure devices (such as acid eggs, air lifts, pulsometers etc). Pumps may be divided into piston (reciprocating), centrifugal, propeller, rotary-displacement, density, impact and momentum and turbine pumps. Pumps which... 

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