Swirl ports

In a duplex atomizer (Fig. 2.2), the swirl chamber consists of two sets of tangential swirl ports primary and secondary ports. The primary ports are for low flow rates and the secondary ports are the main passage for high flow rates. During operation, the primary swirl ports are supplied first with a liquid from the primary manifold, while a spring-loaded pressurizing valve prevents the liquid from entering the secondary manifold. When a predetermined injection... 

As mentioned in the previous section, a major drawback of the simplex atomizer is the poor atomization quality at the lowest flow rate due to too-low pressure differential if swirl ports are sized to allow the maximum flow rate at the maximum injection pressure. This problem may be resolved by using dual-orifice, duplex, or spill-return atomizers. Alternatively, the atomization processes at low injection pressures can be augmented via forced aerodynamic instabilities by using air or gas stream(s) or jet(s). This is based on the beneficial effect of flowing air in assisting the disintegration of a liquid j et or sheet, as recognized in the application of the shroud air in fan spray and pressure-swirl atomization. 

Embedded in such models, in which variations were developed [12] are further detailed. The laminar burning velocity is expressed as a function of fuel type, fuel/ air ratio, level of exhaust gas recirculation, pressure, temperature, etc. Furthermore, submodels have been developed to describe the impact of engine speed, port-flow control systems, in-cylinder gross-flow motion (i.e., swirl, tumble, squish), and turbulent fluctuations u. Thus, with a wider knowledge base of the parametric impact of external variables, successful modeling of... 

Various hollow-cone simplex atomizers (Fig. 2.1) have been developed for combustion applications, differing from each other mainly in the way that swirl is imparted to the issuing liquid jet. In these atomizers, swirl chambers may have conical slots, helical slots (or vanes), or tangential slots (or drilled holes). Using thin, removable swirl plates to cut or stamp the swirl chamber entry ports leads to economies of the atomization systems if spray uniformity is not a primary concern. Large simplex atomizers have found applications in utility boilers and industrial furnaces. Oil flow rates can be as high as 67 kg/min. 

Various correlations for mean droplet size generated using pressure-swirl and fan spray atomizers are summarized in Tables 4.4 and 4.5, respectively. In the correlations for pressure-swirl data, FN is the Flow number defined as FN = ml/APlpl) )5, l0 and d0 are the length and diameter of final orifice, respectively, ls and ds are the length and diameter of swirl chamber, respectively, Ap is the total inlet ports area, /yds the film thickness in final orifice, 6 is the half of spray cone angle, and Weyis the Weber number estimated with film... 

Pressure nozzles are somewhat inflexible since large ranges of flowrate require excessive variations in differential pressure. For example, for an atomiser operating satisfactorily at 275 kN/m2, a pressure differential of 17.25 MN/m2 is required to increase the flowrate to ten times its initial value. These limitations, inherent in all pressure-type nozzles, have been overcome in swirl spray nozzles by the development of spill, duplex, multi-orifice, and variable port atomisers, in which ratios of maximum to minimum outputs in excess of 50 can be easily achieved(34). 

Figure 17.2 Twenty frame composite image of the flame within the Countercurrent Swirl Combustor (exhaust port is on the right)...

Open the capsule and sprinkle the entire contents over approximately 10 ml of water and flush with swirling through a prewetted 16 French gastrostomy tube fitted with funnel at the port end. Additional aliquots of water are used to transfer all pellets and to flush the tube. Do not attempt the administration of pellets through a nasogastric tube. 

Pulverized coal is fed directly from a variable speed auger into the high velocity primary air stream which conveys it to the injector at the top of the furnace. The coal and primary air enter the combustor through a single low-velocity axial jet. Secondary combustion air is divided into two flows which enter the combustor coaxial to the primary stream. Part of the flow is introduced through a number of tangential ports to induce swirl which is necessary for flame stabilization. The remainder enters the combustor axially. The two secondary air streams are separately preheated using electrical resistance heaters. 

In an adaptation of the method of Brown and Brown as a student experiment" an Erlenmeyer flask with a side arm carrying a wired-on rubber bulb (for a medicine dropper) is charged with water, platinic chloride solution, and Norit, stabilized borohydride solution is added, followed by a solution of substrate (enrfo-norbomene-ci.t-5,6-dicarboxylic acid) and coned, hydrochloric acid. The flask is capped with a large serum stopper, which is wired on. Borohydride solution is injected through the rubber port with a syringe until the rubber bulb inflates to a sizable balloon. The syringe is withdrawn, and the flask swirled until deflation of the balloon indicates that further borohydride is required The course of the reaction is easily followed, and a balloon pressure of about 10 p.s.i. promotes rapid reaction. 

In a countercurrent spin dryer, a principle of two coaxial cocurrent swirls of gas is applied. An exemplary dryer scheme working according to this principle is shown in Figure 33.8. The cylindrical chamber is equipped with a series of side ports that introduce air tangentially into the... 

A strainer removes solids from a process before they can enter a pump and damage it. A cyclone is used to remove solids from a gas stream. A typical cyclone is shaped like a V-bottomed tank with a port in the top, bottom, and upper side. Gases and solids enter the top upper side of the tank and are swirled around the tank. Solids drop to the bottom of the cone while gases escape out the top of the tank. Demineralizers remove dissolved substances from a fluid. 

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