SEPARATION OF PARTICLES IN CHANNELS ROTARY ENGINE

The article considers the separation of particles in channels with different relative length. It is shown that the intensity of turbulence at the inlet section of the channel varies considerably in its length. The dependence of the turbulence damping along the channel expressing by fraction of the distance is shown. The ratio of the particle separation efficiency out the gas flow in the rotor channel is defined. The values of particle separation efficiency in the channel for the angle = /4 in turbulent aerosol flow is shows, including without mixing the particles.


INTRODUCTION
Centrifugal dust separators with additional particles separation in rotor channels are studied in [1−2] but the conclusions about the efficiency of these processes are discrepant.Separation of particles is studied in channels with relative length not higher than l/h = 5÷6.In work [3], the information is that just on this length the strong damping of the «external» turbulence takes place and it is clear that an effective separation should be taken in the channels with the relative length l/h>7.Calculations of particle separation with allowance for turbulence are compared with experiment.In works [3,4] the different types of rotary machines are described and the results of experimental and theoretical study of the separation of moisture from flowing turbines parts of are given, efficiency of co-channel separation and from the space over the rotor blades at varying geometric parameters of stages of are analyzed.In work [5] there are a description of the structure and a scheme of turboseparator layout for gas condensate liberation from natural gas.A good performance and high efficiency compared with gravity separators are noted, and the same time the turboseparator weight 52 times less than the g gravity separator at the same working condition.

EXPERIMENTAL SETUP AND PROCEDURE
The scheme of the centrifugal separator [5] is shown in Fig. 1. 1 Corresponding author: veradee@mail.ru

Results and discussion
Turbulent motion of the aerosol in the channel is described by an equation similar to [6] (sign averaging falls) with boundary conditions ɫυ y − (D y ∂c/∂y)| y=0 =0, ɞɫ/ɞɭ| ɭ=h =0, ɫ(0,ɭ)=ɫ 0 , where υ δ •sinα; υ x =W x −υ δ •cosα; υ δ =ω 2 Rτ; τ=δ 2 ρ δ /18ȝ.Here υ y , υ x − averaged particle velocity components in the channel; ɯ, ɭ -coordinates; α -angle of channel inclination to the radial direction; ωangular rotor velocity; W x , W y -averaged gas velocity component in the ɯ-th and the radial direction; δ, ρ δdiameter and density of particle; μ − coefficient of dynamic gas viscosity; R -rotor radius; ɫ − the concentration of particles size δ; ɫ 0 -the concentration of particles size δ 0 at the rotor inlet; D ycoefficient of the particles turbulent diffusion, defined as The intensity of turbulence at the inlet channel section varies in its length considerably.Damping of the «external» turbulence occurs quickly and under relative channel length x/h=15 and it appears slightly at all levels of initial perturbance [7].Denominating the channel length of a fraction of the distance lɬ t. e. distance of external turbulence damping, it can represent the dependence of the turbulence damping along the channel in a generalized form , where x =ɯ/1 ɬ , ɚ §0,01, b §2.
Turbulent diffusion coefficient D y0 =hW * can be defined as follows.In the flowing part of the device between the enclosure and the rotor the turbulent gas flow (just as vortex flow) is realized, where there is a core of quasi-potential distribution of tangential velocities.The equation of the angular gas momentum for flat and symmetric flow looks like where w r ,w ĳ , -radial, tangential components of the gas velocity; τ rĳ -turbulent shear stress; ρ -gas density.
Integral of angular momentum equation can be written as Based on the general terms of the semiempirical theory of turbulence turbo, we obtain where U ɪ =ωR, W r -radial component of the gas velocity at the rotor boundary.Efficiency of particles separation out of the gas flow in rotor channel is determined by ratio

Conclusion
Table 1 shows the efficiency of particle separation in a channel for corner Į=ʌ/4 under turbulent flow aerosol, in parentheses the values of efficiency is indicated without particles mixing.
The table shows that in the range Ș 1 =0,4-0,99 there are a significant difference in the efficiencies.

Figure 3 .
Figure 3. Particles movement in the channel The components of the particle velocity in the channel by centrifugal force and entrained gas stream forces are shown in fig.3.Coriolis forces are not considered because of their smallness.It is taken that the turbulent diffusion coefficients of particles and gas are identical, the values υ y , W x do not depend on ɯ, ɭ.
, where l y − the characteristic length of the turbulent flow, equal to the order of channel height h.The last statement is due to the fact that external vortices break up at the entrance to the rotor and they have a scale equal to the distance between the channel plates.At the channel inlet , velocity, expressed through the shear stress at the rotor boundary.

Table 1 .
Efficiency of particles separation in the rotor channelThis work was supported by as part of the program to improve the competitiveness of the Tomsk State University, Tomsk Polytechnic University