RU28395U1 - Device for sound-luminescent control of impurities in running water - Google Patents

Description

Device for sound-luminescent control of impurities in running water

The utility model may find application for monitoring the purity of drinking and industrial water.

A similar device is known, which contains a series-connected acoustic wave generator and emitter with a flat aperture with a diameter of 70 mm, also containing a cuvette with water and a photomultiplier for observing sound luminescence (sonoluminescence) during acoustic cavitation in a liquid (BC Teslenko, G.N. Sankin. A. P. Drozhzhin, Glow in water and glycerin in a field of plane shock-acoustic waves, Novosibirsk: Proceedings of the MA Lavrentyev Institute of Hydrodynamics SB RAS, 1996).

The disadvantage of the analog device is the need to create short shock-acoustic waves at significant intervals, which does not allow for continuous monitoring of sound luminescence in the flowing fluid.

A similar device is known, which contains a series-connected generator and emitter of acoustic waves with a radiating surface in the form of a segment of a sphere with an aperture of diameter 70 mm, also containing a cuvette with water and a photomultiplier for observing luminescence during acoustic cavitation in a liquid.

This analog device uses shock acoustic waves with a bipolar profile in the form of a compression wave with a duration of 2 μs at an acoustic pressure of 40 MPa (BC Teslenko, Yu.E. Danilov, VP Safonov. Sonoluminescence kinetics and colloidal particle formation at focusing of shock waves in a liquid. - Novosibirsk: Acoustics of heterogeneous media, issue 112, 1997 - p. 235241).

This analog device also does not allow continuous monitoring of sound luminescence in the flowing fluid.

The closest analogue selected for the prototype of the utility model is a luminescence apparatus containing a series-connected generator and a cylindrical emitter filled with the test liquid, also contains a cooled cell with the emitter, also contains a photomultiplier

GOl N29 / 02

for observing luminescence in a cuvette (P. Jarman. Measurements of Sonoluminescence from Pure Liquids and Some Aqueous Solutions - Proc. Phys. Soc. (London), vol. 73, No. 472 - p. 631).

The disadvantages of the prototype device are, firstly, the need to supply powerful acoustic waves, leading to the heating of the emitter and the need to cool it, secondly, the inability to use it to observe the flowing fluid, and thirdly, the possibility of liquid splashing on the quartz window of the photomultiplier , which will lead to measurement errors.

The objective of the utility model is luminescent control of the purity of the flowing water.

The proposed utility model - a device for sound-luminescent control of impurities in a liquid - as well as a prototype device, has a cell, quartz glass and a photomultiplier, optically coupled: there is also a series-connected generator and emitter, which is made with a flat diameter equal to the diameter of the cell.

The cuvette is made in the form of a pipe segment with metal walls with a smaller diameter // 2, I - the sound wavelength in water. The length of the cell is selected in several wavelengths. The pipe is closed with a hard cap.

Quartz glass and a photomultiplier are located at a distance / in the antinode of a standing sound wave, having the form

And therefore

/ n- ,, 2.3 ...,

since the full number of half-waves fits along the length of the pipe.

To create cavitation at normal static pressure in a flowing fluid with continuous radiation, the intensity of acoustic radiation should be at least 0.3 W / cm. Therefore, it is enough to have an intensity of 0.25 W / cm, which will ensure the absence of erosion on the emitter and cavitation in the antinode of acoustic pressure in a standing wave.

/-.hAcos. 4

the proposed device for sound-luminescent flow control of impurities in running water contains a cell 1 with a diameter less than D / 2, where l is the sound wavelength in the liquid, with metal walls with a thickness of at least X. "/ 10, where Yam is the sound wavelength in the material pipe walls (by a pipe we mean a waveguide with a round or rectangular section). The cuvette has an inlet plug 2 and an outlet fitting 3. A photomultiplier 5 is connected to the cuvette through a quartz glass 4. Acoustic vibrations are excited by a series-connected oscillator 6 and emitter 7.

The principle of operation of the device is based on the fact that the addition of impurities to water of organic origin or solid mineral particles increases the level of luminescence, which is mainly due to an increase in temperature in vapor-gas cavitation bubbles to 10 K. To do this, it is necessary that the maximum pressure in the collapsing bubble be as big as possible. As you know (Ultrasound. Little Encyclopedia, edited by I.O. Galyamina - M .: Sov. Encyclopedia, 1979):

where R Po + Ra - the sum of the static and excess acoustic pressure, Q gas pressure in the liquid,

7 / y - the ratio of specific heat at constant pressure and volume

respectively.

The larger γ, the greater Pmax and, therefore, the greater the sound luminescence due to the fact that adiabatic compression of gas and vapor (which behaves like a gas at high rates of change in the volume of the bubble) leads to heating inside the collapsing bubble to temperatures of the order of 10 K. If Cp of air of the order of 0.237, then, for example, hydrogen sulfide has 245, ammonia (vapors) has 536. The addition of organic impurities increases the ratio of the mixtures and leads to increased luminescence. The increase in the number of cavitation nuclei per unit volume of liquid also leads to this. As these "nuclei, solid particles in the liquid can act.

P 0

max X - S

transverse dimensions are also smaller than Y2, where I is the sound wavelength in water). The waveguide is closed by a rigid acoustic cover. For this device, there is no need for very rigid walls and the lid of the cell. Therefore, it is sufficient that the walls of the cuvette be a thickness of at least l „/ 50. For example, in water at a frequency of 10 kHz, the wavelength in water is cm, and the wavelength in steel is cm. The effect of the elasticity of these walls will not affect the formation of cavitation in antinodes of acoustic pressure.

In such a cuvette 1 — a waveguide — a one-dimensional standing wave can be represented as a superposition of two waves traveling towards each other and passing one after the other at the ends

n A | -KiX-ikx-iip

 22

For a “rigid cover, the vibrational velocity is at and at. . in addition, and k n7r / L, where n 1, 2, 3 ... Therefore,

R. Lso5r

The eigenfrequencies of the hollow waveguide are in the ratios 1: 2: 3 ..., i.e. form a complete harmonic series, and an integer number of half-waves fit along the length of the waveguide. In this case, the pressure antinodes will be at

Acoustic cavitation that occurs when a high-intensity sound wave propagates is formed due to discontinuities in the cavitation nuclei — microscopic gas bubbles, solid particles with cracks filled with gas, etc. An inhomogeneous sound field is observed in the cuvette. This leads to the fact that along with the pulsations, the bubbles move forward. In a standing sound wave, the direction of motion of the puzzle depends on the ratio between its radius R and radius Rpey - the resonant radius of the bubble. If the bubble size is smaller than the resonance one, the bubbles pulsate in phase with fluctuations in acoustic pressure and migrate to the pressure antinode, and when pusfki move to pressure nodes. For example, at a frequency of f-10 kHz, one should expect the movement of bubbles to pressure antinodes. For example, for poofs with cm in the field of a standing wave, the length of which is cm, the amplitude of the acoustic pressure. 4

V -)

/ I p.

atm and poise fluid viscosity coefficient. the speed of movement of bubbles cm / s at, 0 atm.

The operation of the device is as follows. Through the inlet 2 and outlet 3 fittings, the cuvette is connected to the water conduit, running water is supplied through it. Generator 6 and generator 7 create a standing sound wave in the cell. In the antinode of cavitation pressure, the maximum and sound luminescence is observed through quartz glass 4 using a photomultiplier 5. The presence of organic and solid impurities in water leads to increased sound luminescence. which indicates the degree of pollution of running water. At the antinode, the acoustic pressure doubles and the intensity is 0.35 W / cm. Location on

those. in section M, where the intensity will be at least 0.3 W / cm, the water should be at least 1.2 s. Otherwise, the cavitation threshold will be higher and the intensity of 0.3 W / cm will be insufficient. Therefore, the ratio of the cross section of the cross section of the inlet fitting Ssx to the cross section of the cell is selected from the relation

where Vg is the input stream velocity.

Thus, the proposed device provides a solution to the problem.

2plM arccosO.86

-

5 1 7

 kyuk Device

Claims (1)

A device for sound-luminescent control of impurities in water, containing a cuvette, an acoustic vibration exciter, optically coupled quartz glass and a photomultiplier, characterized in that the cuvette with inlet and outlet fittings has a rectangular, square or circular cross section with dimensions smaller than half the wavelength in a liquid at a working frequency, the length of the cell is several wavelengths in a liquid at a working frequency, the thickness of the metal walls is at least one fiftieth of the new wave in the material of the walls of the cuvette, the causative agent of acoustic vibrations is made in the form of a rod emitter, the emitting plane of which is located on one side of the cuvette and is equal to the cross section of the cuvette, the other side of the cuvette is closed by a lid, quartz glass is located at a distance l from the photoluminescence approximately equal to

, where λ is the sound wavelength in water,

..., and the ratio of the cross section of the inlet fitting S _I to the cross section of the cell S _cuv is selected from the ratio

where V _I - input flow rate,

while the radiated power with continuous radiation provides the intensity of the radiated sound of at least 0.25 W / cm ² .