Nozzle capillary

Radiation nozzle system for high-tem-peiatuie election diffiaction experiment for compounds with low volatility (1 - filament, 2 - supporting rod, 3 — ceramic supporter, 4 — sample container, 5 - nozzle capillary, 6 - thermocouple)... 

Within the frame of the present first series of experiments it was almost always oxygen which was injected into supercritical water-methane mixtures. There were several reasons for this first choice. One of these was the desire, to study rich flames and their possible products first. Often the water to methane mole fraction ratio was 0.7 to 0.3. But mixtures down to a methane mole fraction of 0.1 were also used. It was possible, however, to inject oxygen and methane simultaneously into the supercritical water and produce a flame. Not possible was the production of true premixed flames. After a retraction of the thin inner nozzle capillary of the burner (see Fig. 1 b) the two gases could be mixed just below the reaction cell, but the flame reaction proceeded from the nozzle tip in the cell back towards this mixing point immediately. 

A semi-continuous SAS apparatus, as a rule, consists of two pumps used to deliver the liquid solution and supercritical CO2, respectively. A cylindrical vessel is used as the precipitation chamber. The liquid mixture is delivered to the precipitator through an injector. Different arrangements have been proposed in the literature like nozzles, capillaries, vibrating orifices and coaxial devices. Supercritical CO2 is delivered through another inlet port that can be located on the top or the bottom of the vessel. The pressure in the precipitator is regulated by a micrometering valve located at the exit of the chamber. A stainless-steel fiit located at the bottom of the precipitator is used to collect the produced powder. A second vessel located downstream the micrometering valve is used to recover the Uquid solvent. 

Substrate Solvent Antisolvent P (MPa) T(K] Nozzle/capillary dimension (pm) Morphology/ particle size Reference... 

The cylindrical nozzles outlet diameters are 0.7, 0.9, or 1.8 mm. LjD ratios are varied in between LjD = 0 0. The roughness of the nozzle capillary is not measured directly, but estimated with values from literature (Table 16.1). The highest roughness is achieved by drilling the smallest roughness is estimated for drawing. 

Pressure measurements inside the nozzle capillary are done with a transducer (Wagner, Type P-05). The pressure is measured at three locations in the nozzle capillary, at the nozzle inlet (0 mm), in the middle between nozzle inlet and outlet (9 mm), and at nozzle outlet (18 mm). The measurements last for 10 s and data is recorded in a frequency of 0.1 Hz. Measurements of the spray temperature are... 

Schematic diagram of an electrospray inlet/ion source. A spray produced from the high electrical voltage (HT) on the capillary moves toward a hole in the electrical counter electrode. After removal of much solvent, sample ions continue under their momentum through the hole and then through the nozzle and skimmer, where most remaining solvent is removed.

The dimensions of concentric-tube nebulizers have been reduced to give microconcentric nebulizers (MCN), which can also be made from acid-resistant material. Sample uptake with these microbore sprayers is only about 50 xl/min, yet they provide such good sample-transfer efficiencies that they have a performance comparable with other pneumatic nebulizers, which consume about 1 ml/min of sample. Careful alignment of the ends of the concentric capillary tubes (the nozzle)... 

In a concentric-tube nebulizer, the sample solution is drawn through the inner capillary by the vacuum created when the argon gas stream flows over the end (nozzle) at high linear velocity. As the solution is drawn out, the edges of the liquid forming a film over the end of the inner capillary are blown away as a spray of droplets and solvent vapor. This aerosol may pass through spray and desolvation chambers before reaching the plasma flame. 

Three common types of nozzle are shown diagrammatically. Types A and K are similar, with sharp cutoffs on the ends of the outer and inner capillaries to maximize shear forces on the liquid issuing from the end of the inner tube. In types K and C, the inner capillary does not extend to the end of the outer tube, and there is a greater production of aerosol per unit time. These concentric-tube nebulizers operate at argon gas flows of about 1 1/min. 

The sample solution is pumped along a narrow capillary tube, the end of which becomes the nozzle of the nebulizer. On the outside of the capillary near its nozzle end, an electrical heater rapidly... 

Fig. 27. Abrupt contraction cell for flow visualization, birefringence and degradation measurements A inlet (from a peristaltic pump of a pressurized reservoir B outlet (atmospheric pressure or partial vacuum) C interchangeable metallic nozzle with a sapphire tip D capillary flow meter E glass window for flow visualization AP pressure drop (from pressure transducers)...

The aqueous solution flows from the jet nozzle to a receiving capillary with no overflow into the outer stream, resulting in short contact times of around 0.05 s. Analysis is implemented by flowing the outer organic phase continually through a closed loop and monitoring concentration changes spectrophotometrically. The apparatus used by Freeman and Tavlarides employed capillaries with internal diameters of 2 mm, and the... 

Analytical and empirical correlations for droplet sizes generated by ultrasonic atomization are listed in Table 4.14 for an overview. In these correlations, Dm is the median droplet diameter, X is the wavelength of capillary waves, co0 is the operating frequency, a is the amplitude, UL0 is the liquid velocity at the nozzle exit in USWA, /Jmax is the maximum sound pressure, and Us is the speed of sound in gas. Most of the analytical correlations are derived on the basis of the capillary wave theory. Experimental observations revealed that the mean droplet size generated from thin liquid films on... 

Krishnamurthy et ah (K13) have confirmed the above conclusion and have developed an expression for evaluating the bubble volume under conditions of flow when the corresponding volume for static conditions is given. These authors used capillaries of different diameters ground at the tip as nozzles. The capillaries were arranged horizontally, and the fluid travelled vertically so as to add to the buoyancy. The liquid viscosity was varied from 1 to 30 cp and the surface tension from 62 to 70 dyn/cm. 

The burner is shown in Fig. 1 b. Its screw (A) and cone (B) fit into the cell opening [5] (see Fig. 1 a). The injector nozzle (C) has two concentric tubes to inject two gases simultaneously, if desired. The outer tube is of stainless steel with 3 mm o.d. and 1.5 mm i.d. The inner capillary of the same material, which protrudes slightly, has 0.8 mm o.d. and 0.5 mm i.d. Both concentric tubes can receive gas separately from the twin valve (D) below, which can be heated to 50°C to prevent formation of solid gas hydrates. 

In many processes (such as oil recovery, blood flow, underground water), one encounters liquid flow through thin (micrometer diameter), noncircular-shaped tubes, or pores. In the literature, one finds studies that address these latter systems. In another context of liquid drop formation, for example, in an inkjet nozzle, this technique falls under a class of scientifically challenging technology. The inkjet printer demands such quality that this branch of drop-on-demand technology is much in the realm of industrial research. All combustion engines are controlled by oil drop formation and evaporation characteristics. The important role of capillary forces is obvious in such systems. 

Tests with Aerosol Sprays. One of the chief means of applying concentrated oil sprays is in aerosol form. An aerosol generally remains suspended in the air for some time and is carried by normal wind or air currents. Aerosols are probably best adapted to interior applications but have been used with some success outdoors. They may be produced by liquefied-gas formulations released through capillary nozzles, by steam and air atomization, by centrifugal disks and rotors, by extremely high pressure, and by heat vaporization. 

Interfacial tension may be measured by a number of techniques, including determining how far a solution rises in a capillary, by measuring the weight, volume or shape of a drop of solution formed at a capillary tip, measuring the force required to pull a flat plate or ring from the surface or the maximum pressure required to form a bubble at a nozzle immersed in the solution. Ring or plate techniques are most commonly used to determine y of milk. 

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