8th INTERNATIONAL SIBERIAN WORKSHOP AND TUTORIALS EDM’2007, SESSION V, JULY 1-5, ERLAGOL 289

ISSN 1815-3712 ISBN 978-5-7782-0752-3 © Novosibirsk State Technical University

Ultrasonic Chemical Reactors

Igor I. Savin, Sergey N. Tsyganok, Andrey N. Lebedev, Student member, IEEE, Dmitry V. Genne, Stu-dent Member, IEEE, Elena S. Smerdina, Student Member, IEEE

Biysk Technological Institute (branch) of Altay State Technical University after I.I. Polzunov, Biysk, Russia

Abstract— The article is devoted to different types ultra-sonic chemical reactors for laboratory and industrial us-ing. Experimental results are given. Index Terms—ultrasonic, sonochemistry, ultrasonic reac-tor, cavitations.

I. INTRODUCTION

HE PRESENT-DAY INDUSTRIAL ENTER-PRISES continuously increase tempo of industrial production. Usually, for this purpose it is neces-

sary to modernize or completely to change the process flowsheet. It is widely known, that using of high in-tensity ultrasonic oscillations allows intensifying many technological processes, such as impregnating of com-posite materials, drilling of brittle and extra-hard mate-rials, dissolution, extraction, emulsification, washing and clearing. [1,2]

A plenty of researches being carried out at present moment specify that speed of passing the majority of chemical reactions increases under action of an acous-tic field and that some reactions do not pass without action of ultrasonic oscillations [3-5].

Cavitation is considered as a major factor which influences on reaction speed. The temperature inside cavitation bubbles while collapsing attains approxi-mately 5000 K, pressure attains approximately 100 MPa and velocity of a collapse attains about 400 km/h. At such bubble collapsing the powerful shock-wave [3] is created.

Providing of similar requirements is possible at in-tensity of ultrasonic action from 100 W/cm2. Since the acoustic oscillations of audio frequency and high in-tensity providing is rather difficult, using of ultrasonic frequency oscillations (above 20 kHz) obtains wide extending.

For implementation of such technological proc-esses there is a special class of technological apparatus called ultrasonic reactors; and for providing researches

of reaction passing under action of acoustic oscilla-tions there is a science called acoustic chemistry.

II. ULTRASONIC REACTORS FOR LABORA-TORY

Now there is a lot of ultrasonic reactors types, which differ from each other with intensity of ultra-sonic oscillations introducing into a fluid and possibil-ity or impossibility of the flowing processing [4,6] (Fig. 1).

Fig. 1 Existing types of ultrasonic reactors [4].

The peak of ultrasonic action provides with the ul-trasonic reactor represented in Fig. 2.

Such reactors are able to process about 300 ml of liquid with intensity up to 200 W/cm2.

In cases when for experimental purpose it is enough to process several tens of milliliters the ultrasonic ap-

T

290 8th INTERNATIONAL SIBERIAN WORKSHOP AND TUTORIALS EDM’2007, SESSION V, JULY 1-5, ERLAGOL

paratus for processing liquid in test tubes is used. Dis-tinguishing feature of such apparatus is presence of two replaceable working tools for an ultrasonic oscil-latory system.

Fig. 2 Embodiment and appearance of ultrasonic reactor «UZOR

Fig. 3 The ultrasonic reactor for processing liquids in test tubes.

a)

b)

c)

d)

e)

f)

Fig. 4 - Ultrasonic reactors of various powers. a) ultrasonic apparatus «MUSA» (400 VA), b) ultrasonic apparatus «Potok» (630 VA), c) ultrasonic apparatus «Crystal - 2» (1000 VA), d) ultrasonic apparatus «Potok-3» (1000 VA), e) ultrasonic appara-tus «Bulava», model 1000-3 (3000 VA), f) ultrasonic apparatus «Bu-lava», model 1000-6 (6000 VA)

One working tool is intended for direct input of os-cillations in the test tube, and another one is for non-contact processing of liquids. The working tool has shape of the hollow cylinder in which test tube with reagents is placed, in space between walls of test tube

SAVIN et al.: ULTRASONIC CHEMICAL REACTORS 291

and the working tool there is a liquid through which transmission of oscillations to test tube walls is carried out (Fig. 3).

Due to small volumes of the processing liquid it is possible to achieve the intensity of ultrasonic action about 300 W/cm2.

III. ULTRASONIC REACTORS FOR INDUS-TRIAL APPLICATION

The major drawback of the foresaid reactors is the small processing volume per unit of time. For labora-tory it is not a major drawback, but for the industrial applications the other embodiment of the reactor is re-quired. In this case, the optimal solution is the flowing processing of liquid.

Fig. 5 The ultrasonic oscillatory system in technological volume.

Fig. 6 - the Ultrasonic reactor of ultrahigh intensity. 1 - techno-logical volume, 2 - ultrasonic transducer, 3 - the channel for deliv-ery of initial components and evacuation of reaction product, 4 - the piezoelectric elements, 5 - reflective frequency- dropping patches.

The laboratory of ultrasonic processes and appara-tus designs a lot of apparatus for the flowing process-ing of liquid mediums with power from 400 VA up to 6000 VA (Fig. 4).

Distinguishing feature of apparatus with power

more than 2000 VA is use of the working tool with the extended radiating surface. The working tool is the se-ries joined several step-radial concentrators; such form of the working tool allows to extend the radiating sur-face in several times in comparison with classical sin-gle- and two-half-wave oscillatory systems. (Fig. 5).

For providing super intensive action on liquid me-diums, it is promising to design the embodiment of ul-trasonic reactor for the flowing processing in form of truncated dodecahedron with piezoceramic assemblies on its hexangular sides. Using of such radiator em-bodiment will allow achieving the intensity of 500 W/cm2 [7] (Fig. 6).

IV. EXPERIMENTAL RESEARCHES

The experimental researches on processing milk and sewage with ultrasonic oscillations of high inten-sity have been carried out using apparatuses designed.

By means of apparatus «MUSA» examination of influence the ultrasonic oscillations on taste property, biological parameters of milk and its storage stability was carried out. Results of test have shown that the radiated milk is kept longer than not processed one.

Thus the amount of bacteria in milk drops from ini-tial 15000 unities to 5000 in the end of the first proc-essing cycle and to 1000 in the end of the third cycle (Table 1).

TABLE 1. RESULTS OF ULTRASONIC MILK PROCESSING. Experiment amount of bacteria Milk 15000 Milk first cycle 2 minutes 10500 Milk first cycle 5 minutes 7000 Milk first cycle 10 minutes 5000 Milk second cycle 2,5 minutes 1000 Milk second cycle 7,5 minutes 6500 Milk third cycle 2,5 minutes 2000 Milk third cycle 7,5 minutes 1500 Milk third cycle 10 minutes 1000 Also it is determined that decrease in processing

velocity from 1 l/min to 0,5 l/min allows to essentially reduce quantity of milk operation cycles to 1-2 with amount of bacteria in milk 1000-2000 unities without losses of taste properties.

Changing in the amount of bacteria in milk on the second cycle of processing are related with variation of productivity from 1 l/min to 0,5 l/min.

The inoculation of milk was made with Kessler and Kmafanm mediums, produced by Obninsk-city on GOST procedures.

292 8th INTERNATIONAL SIBERIAN WORKSHOP AND TUTORIALS EDM’2007, SESSION V, JULY 1-5, ERLAGOL

The sewage processing was provided with appara-tus «Bulava», model 1000-3 (Table 2), the represented results show efficiency of ultrasonic oscillations using for water purification.

TABLE 2. Results of sewage processing with ultra-sonic oscillations of high intensity.

Water parameters input output

рН 7,6 7,7

UEP 0,102 0,0577

Suspended matter >2000 122,2

Solid residue 612,2 305,6

BPK5 276 15,6

Permanganate oxidability 191,8 18,8

Ammonium 46,5 19,5

Phosphates 0,95 0,2

Sulfates 28,9 10,4

APAV 3,21 2,23

Nitrites, nitrates, clarity below the rate

V. CONCLUSION

The represented embodiments allow satisfying the requirements both the industrial enterprises and the re-search organizations. The presented experimental re-sults confirm a possibility and promising of using the ultrasonic technologies both in industrial plants and laboratory researches.

REFERENCES [1] Khmelev V.N., Popova О.V. Multiurpose ultrasonic appa-

ratuses and their application in conditions of small manu-factures, agricultural and housekeeping: the scientific monography / AltGTU. - Barnaul: AltGTU

[2] Khmelev V.N., Barsukov R.V., Tsyganok S.N. "Drylling of brittle and hard materials". Barnaul: AltGTU, 1999

[3] Kenneth S. Suslick. "Sonochemistry" Kirk-Othmer Ency-clodpedia of Chemical Technology, Fourth Edition, vol. 26; John Willey&Sons, Inc.: New York, 1998, pp.516-541

[4] Design of Ultrasound Reactors: Choice of Working Condi-tions and Sound Fields for Precipitation, Particle Fragmen-tation and Organometal Reactions, Christian Horst, Yuh Shuh Chen, Jost Kruger, Ulrich Kunz,Andreas Rosenplnter and Ulrich Hoffmann, Plenary Lecture.

[5] M.G.Sulman Influence of ultrasound on catalysis processes, "Uspehi Himii", 69(2), 2000, pp.178-191.

[6] C.Horst, A.Lindermeir, U.Hoffman. Design of ultrasound reactors for techical scale organometallic and electrochemi-cal synthesis, TU Hamburg-Harburg Reports on Sanitary Engineering 35, 2002.

[7] Ultrasonic Chemical Reactor, claim of Russian patent №2007101744/15 by 29.11.2006.

Igor I. Savin, Ph.D (ultrasound) —principal engineer of MSIA department of Biysk technologi-cal institute. Laureate of Russian Government premium for achievements in science and en-gineering. Area of scientific in-terests is application of ultra-sound for an intensification of technological processes. IEEE student member since 2001, IEEE member since 2006.

Sergey N. Tsyganok was born in Biysk, Russia, 1975. Now he is Ph.D (Machinery), he received degree on information measur-ing engineering and technolo-gies from Altay State Technical University, key specialist of electronics. Laureate of Russian Government premium for achievements in science and en-gineering. His main research in-terest are development of high -effective multifunctional oscilla-tors for ultrasonic technological devices.

Andrey N. Lebedev (S'03) was born in Kiselevsk, Russia in 1983. He received degree on in-formation measuring engineer-ing and technologies from Biysk Technological Institute of Alt-STU. He is post-graduate stu-dent of Biysk Technological In-stitute.. His research interests is finite-element modeling.

Genne V. Dmitry (S’06) was born in Biysk, Russia in 1982. He received degree on informa-tion measuring engineering and technologies from Biysk Tech-nological Institute of AltSTU. He is post-graduate student of Biysk Technological Institute. His main research interest are development of high -power electronic generators for ultra-sonic technological devices.

Elena S. Smerdina (S’06) was born in Pobrade, Lithuania, 1983. She received degree on Information science and measur-ing engineering in Altay State Technical University. Member of "Woman in Engineering" IEEE work group since 2006.