Axial air swirlers

FIGURE 15.1 Axial air swirlers (a)-dual-lead spiral (b)-the multiple-start screw insert and (b-a)multibladeaxial air swirler. 

At liquid feeding into in a zone over an axial air swirler (Figure 15.5a) is formed a cone-shaped spray of liquid drops. 

Directly over an axial air swirler where the vortex flow is formed, it is offered to present velocity profiles the approached equations (Uollis, 1972) ... 

Centrifugal Dedusters with Axial Air Swirlers of Type AV.270... 

CENTRIFUGAL DEDUSTERS WITH AXIAL AIR SWIRLERS OF TYPE AV... 

The increase in charge G of the cleared gas at invariable value of angular speed leads to proportional raise of an axial velocity of gas and a decline of separation of a dust owing to decrease of duration of stay of firm corpuscles in air swirler shovels. Considering also that hydraulic losses increase proportionally to a square of an axial velocity of gas, it is expedient to secure with moderate values w (to 40 mps). 

The increase in diameter of an air swirler D on the one hand eompli-cates gas clearing, but with another leads to deerease of an axial veloeity of gas and to increase in a time of a finding of firm eorpuseles in rotor channels. As a result separation improves. For example, in our research at increase of. D in 1.3 times, the axial velocity has decreased almost 2 times and factor droppings of a dust has decreased also in 2 times. The rotor volume has essentially increased by 70 percent. 

For provision of sufficient efficiency of a WCD in diameter more than 50°mm are expedient for inducting a liquid in core zone. Such feeding into can be carried out through the radial, axial, U- and G-shaped tubules also above or below an air swirler (Figure 15.5) (Nurste, 1973 and Kiselev,... 

So the air swirlers, which design features strain velocity profiles, for example, are known in such a manner that, despite a considerable initial twisting of a stream, in axial area, there is no reverse flow or there are rather weak return currents. Besides, at small blade twists chances of reception of undershooting of axial making speed [10-17],... 

Researches show (Kutepov, 1977 and Uollis, 1972) that velocity profiles of a gas stream for geometrically similar air swirlers automodeling to diameter the rotary connection and to a gas rate. In the installed stream gate out an axial zone of quasifirm twirl and a peripheral zone of potential twirl with the matching approached profiles (Kutepov, 1977) ... 

At angle increase T transition fi om air swirler ATV to air swirler AV occurs. Thus, the zone of the maximum speeds moves to periphery. Tangential making speeds at angles = 20° and 30° considerably exceed axial, accepting at coal 45° approximately equal values. 

In process of removal from an air swirler, there is a disproportionation of axial speeds on channel cross-section, and on distance x = 0.8 + 1.0 zone of return currents disappears. 

The bubbling—swirling apparatuswith a parabolic air swirler according to 4)ht.1 contains cylindrical camera Ic an entrance pipe 2, the axial sprinkler 3 perforated by holes of small diameter 4 and silenced with target end. In the cylindrical chamber 1, the pair of air swirlers 5 is consistently installed, and the air swirler on an entry of a gas stream is rigidly fastened to an axial sprinkler 3, and on an exit the air swirler is executed with the central hole, equal 0.2 diameters. 

The bubbling—swirling apparatus with a conic air swirler according to Figure 20.16 contains the cylindrical chamber 1 with an entrance pipe 2, the axial sprinkler 3 perforated by holes of small diameter 4 and silenced with target end. 

The flammability and stability limits of Fig. 19.7 were obtained using fuel-air mixtures with the same equivalence ratio in the radial and tangential inlets, and without an axial jet. The lean flammability limit decreased from 0.57 to 0.4 as the swirl number was increased from 0.6 to 3.75, and the region of high-heat release moved closer to the swirler which represented an acoustic pressure antinode for the naturally occurring oscillations associated with a quarter wave in the entire duct, with frequency close to 200 Hz. Thus, swirl led to an increase in the amplitude of oscillations and to an earlier transition from smooth to rough combustion with antinodal RMS pressures up to 10 kPa, and initiated at an equivalence ratio of 0.5 for a swirl number of 3.75... 

The mixer includes three air passages equipped with swirlers leading into the combustion chamber. The two central coaxial passages feature axial swirlers, while the external air passage heis radial swirling vanes. Air blast fuel atomizers... 

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