Nozzles quench

Two-Fluid (Pneumatic) Atomizers This general category includes such diverse apphcations as venturi atomizers and reac tor-effluent quench systems in addition to two-fluid spray nozzles. Depending on the manner in which the two fluids meet, several of the breakup mechanisms may be apphcable, but the final one is high-level turbulent rupture. 

Feedstock A higher fraction of 1,050°F+ (565°C+) in the feed. For many refiners, the regenerator temperature is the limit on addition of heavy ends to the feed. High-efficiency feed nozzles can be used. Naphtha quench can be added. 

Install high efficiency Feed Nozzles Lower Preheat Temperature Inject Naphtha Quench to Riser Increase Stripping and Dispersion Steam Switch to a Coke Selective Catalyst... 

A friend developed a unique spray that holds very constant velocity and consistent spray pattern regardless of flow, thereby overcoming turndown problems in other spray nozzles. This is very useful in quench or desuperheating service. Figure 15-1 illustrates this unique spray. 

Figure 11.6 Examples of methanol synthesis converters (a) tube-cooled, low-pressure reactor A nozzles for charging and inspecting catalyst B outer wall of reactor as a pressure vessel C thin-walled cooling tubes D port for catalyst discharge by gravity (b) quench-cooled, low-pressure reactor, A,B,D, as in (a) C ICI lozenge quench distributors (Twigg, 1996, pp. 450, 449 reproduced with permission from Catalyst Handbook, ed. M.V. Twigg, Manson Publishing Company, London, 1996.)...

A new production technique fully cost competitive with current processes could be the reduction of magnesium oxide by carbon to produce magnesium metal as a vapour and carbon monoxide gas this technique, according to Brooks et al. (2006), will involve rapid quenching of the Mg vapour through a nozzle at supersonic velocity to avoid Mg reversion to magnesium oxide. 

Figure 7.8 Rapid-mixing rapid-freezing apparatus.Two syringes (2) are filled with a solution of enzyme and substrate, respectively. By applying a large force (I) on the syringes, the solutions are driven into the mixer (3) whereafter the reaction starts.The reaction mixture flows through a reaction hose (4) and is then sprayed via a thin nozzle (5) in a funnel filled with cold isopentane (—I40°C). This causes a rapid (Sms) quenching of the reaction.The frozen powder is subsequently collected in an EPR tube attached to the funnel (6) and then is ready for EPR measurements.The funnel and EPR tube are held in a dewar with isopentane (—l40°C).The reaction time can be varied by changing the length and diameter of the reaction hose.

SO2 absorption and particulate removal begins at the quench section and continues as the flue gas rises up through the main spray tower where the gas is again contacted with high-density water curtains produced by additional spray nozzles. The spray tower itself is an open tower with multiple levels of the BELCO spray... 

All of the oil from the bottom of zone 3 (at 700°F)> other than the portion that serves as feed to furnace no. 1, is withdrawn through a cooler (500°F) and pumped partly to the top tray of zone 2 and partly as spray quench to zone 1. Some of the bottoms of zone 1 likewise is pumped through a filter and an exchanger and to the same spray nozzle. 

Scattering studies with metastable atoms are in many cases easier (and less expensive) than experiments with ground-state atoms, The discussion that follows is mainly concerned with helium, as most of the information is available for this atom. Figure 2 shows a skeletal setup of the experiment. A helium beam from a supersonic nozzle source is excited by electron impact to its two metastable states. The singlet state can be quenched by the 2g radiation from a helium-gas discharge lamp ... 

Eggleston, Herrera, and Pish 1976 To provide needed data about the use of air entrained by a water spray to dilute flammable vapor releases below the lower flammability limit. Absorption/adsorption effects are insignificant in the case of ethylene and vinyl chloride. Sprinklers and water-spray nozzles vary widely in their efficiency as air movers. Flame quenching was not affected in any of the experiments Water sprays increased the rate of flame propagation. The air-pumping action of a water curtain can be used to set up a barrier to the horizontal flow of vapors. 

The Sauter mean diameter has been found to be the most useful of the above definitions for characterizing the spray produced by a nozzle. It is a good indicator of a spray s performance in complex interactions with a droplet s surface and volume. Applications include spray drying, evaporative cooling, dry scrubbing, gas quenching, and gas absorption (Stavis, 1991). 

The gas leaving the heat recovery equipment contains the soot formed in the reactor and most of any ash present in the feedstock some of the ash is deposited in a void space in the bottom of the reactor from which it is removed during periodic inspection shutdowns. The gas passes to a quench vessel containing nozzles for multiple water-sprays which scrub most of the soot from the gas. Additional heat recovery can be accomplished downstream of the quench vessel by heat exchange of the quenched product gas with cold feed water. Any residual soot in the gas is removed in a scrubber column. The SGP product gas contains less than 5 ppmv soot. 

When the hot (1200-1350°C) calcined coke leaves the kiln, it is transferred to a rotary cooler. This consists of a steel cylinder, usually lined with refractory at the feed end, that is slightly inclined to induce downward travel as it is rotated. In the cooler the hot coke is quenched by water sprayed from a number of nozzles exit temperature is controlled at about 150°C (300°F) to assure a moisture-free product. 

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