UA71760A - A method for pasteurization of liquid foodstuffs in the flow and a mechanism for realization of the same - Google Patents

Abstract

A method for pasteurization of liquid flow provides for cavitation treatment of liquid in running capacities. An acoustic field having intensity of 140-160 dB at frequency being equal to the resonancefrequency of running capacity is applied on running capacities and liquid, and due to elastic oscillations of running capacity walls the cavitation in liquid is formed.

Description

Description of the invention

The invention relates to the food industry and can be used in the pasteurization of juice, milk and 2 other liquid products.

Considering the fact that most microorganisms die at temperatures of 158"C, the thermal method of pasteurization of liquid products has become the most widespread, in which the product is heated to a temperature of -70-757C, and during sterilization to 1207"C. The main disadvantages of the thermal method of processing liquid products are rather large costs of thermal energy, insufficiently high productivity of the pasteurization process, and the need to carefully observe the temperature regime of processing. In addition, during heat treatment of products, nutritional and organoleptic properties of products deteriorate. Well-known devices for heat treatment of liquid products are plate pasteurizers, which process the product by pumping it through the slits forming the plates, as well as tunnel pasteurizers, heat baths and autoclaves. These devices have the same disadvantages as the method of heat treatment of liquid materials. 12 A common technical solution is the method of extending the shelf life of bread kvass, which we adopted as a prototype (Patent of Ukraine Mo38972 M, 2001, A23I 3/30). The essence of the method is to act on bread kvass with ultrasonic vibrations in the mode of liquid cavitation. This method does not require large expenditures of thermal energy and strict endurance of temperature and time regimes. The disadvantage of this method is low productivity, due to the local effect of ultrasonic vibrations and the need for direct introduction of ultrasound into the liquid.

The closest in technical terms is a device for intensification of sonochemical reactions (Patent of Ukraine

Mo36047 M, 2001, VO1119/10). The device is made in the form of an ultrasonic generator, above which a capillary is installed, which removes the treated liquid from the zone of ultrasonic treatment. This design of the device ensures reliable processing of all liquid, which is removed from the zone of action of ultrasonic vibrations with the help of capillaries. 29 The disadvantage of the device is its low productivity, due to the local effect of the ultrasonic field, the small /"F, the permeability of the capillary.

The invention is based on the task of creating a method and developing a device for processing liquid food products by acting on the processed product in a stream of sound waves in order to ensure the reduction of general contamination by microorganisms and the preservation of the physico-chemical and nutritional properties of the product. Gee)

The method of liquid flow treatment involves cavitation treatment of liquid in flow containers. According to the invention, an acoustic field with an intensity of 140-16OdB is imposed on the flow containers and on the liquid with a frequency equal to the resonance frequency of the container and due to the elastic natural oscillations of the walls of the flow containers, cavitation is created in the liquid.

З Inherent elastic vibrations of the walls of the flow vessels are excited by forced acoustic vibrations of the air medium as a result of the action of the acoustic generator.

When a container is irradiated by an acoustic field, part of the wave energy is reflected from the outer surface of this container, and part is absorbed by the walls and the liquid inside the flow container. At the same time, "the acoustic wave spends part of its energy on the excitation of vibrations of the walls of the container and the creation of cavitation in the Z 50 liquid, which leads to the destruction of microorganisms. c Thus, the liquid that adheres to the inner walls of the containers is subjected to its own oscillations of the walls of the container, and at the same time, the entire liquid is processed by the acoustic field of the generator. Oscillations of the walls of flow containers generate cavitation bubbles that intensively destroy microorganisms.

The lower limit of the intensity of the acoustic field (1404B) is selected from the condition of ensuring cavitation excitation |11. 45 The upper limit (160dB) is selected taking into account the technical capabilities of sound generators. The frequency range 7 of the sound generator is selected from the condition of sound resonance with current capacity. - The device for pasteurization of liquid flow contains an acoustic chamber with a generator of a powerful acoustic field and a flow capacity. According to the invention, the flow capacity is made in the form of flat elements connected to the inlet and outlet nozzles of the liquid supply, and the dimensions of the flow elements are selected from the condition of resonance with the b 20 acoustic field.

The design of the device makes it possible to increase the productivity of the liquid flow processing process by pumping it through a large number of flat flow elements in which cavitation and sound processing takes place, due to the excitation of the walls of the flow elements by the sound generator.

The set goal is achieved by the fact that in the device, the dimensions of flat flow elements of rectangular cross-section are selected based on the condition of ensuring the resonance of the natural frequencies of the walls of the flow elements with a frequency of acoustic generator that provides cavitation treatment of the liquid flow. Flow capacities are installed perpendicular to the direction of propagation of acoustic waves of the generator. Such an arrangement allows the maximum effective use of acoustic energy.

The drawing shows the schematic diagram of the proposed device, Fig. 1 shows a device for processing 60 liquid food products in a stream, Fig. 2 shows the A-A section of the device shown in Fig. 1.

The device consists of an acoustic chamber 1, inside which there is a sound generator 2 and a flow capacity. The flow capacity consists of inlet 3 and outlet 4 nozzles, connected by flow elements 5. To regulate the supply of liquid at the inlet and outlet of nozzles 3 and 4, valves 7 are installed. To ensure the possibility of maintenance, a hatch is provided in the chamber (it is not shown in Fig. ). The walls of the chamber and hatch are sound-insulated, for example, with concrete 6.

The acoustic emitter ensures the generation of a powerful acoustic field. The flow capacity allows you to distribute the flow of liquid over many elements 5 and thereby ensure high productivity and processing quality.

The dimensions of the elements 5 are selected from the condition of resonance of the vibrations of the walls of the flow elements and acoustic excitation. If each flow element is considered as a tube of rectangular section, then the oscillations of the thin frontal walls can be considered as oscillations of a membrane pinched at the edges. The frequency of oscillations of a rectangular membrane (21: 1 in E te and pi o 2 vy- o) and in where E is the modulus of elasticity of the membrane material; c - material density; te1, 2,...; pE1, 2,...; a - membrane length;

b - the width of the membrane.

The device works as follows: turn on the acoustic generator 2. Through the inlet pipe C, the processed liquid is pumped, which is evenly distributed over the flow elements 5. During the pumping of the liquid through the tubes 5, it is subjected to acoustic and cavitation processing. The pasteurized liquid product is packaged in sterile containers. To stop the supply of liquid product at the inlet and outlet of nozzles C and 4, latches 7 are provided.

An example of a specific implementation of the method.

The flow capacity is formed by a multi-element system of flat tubes of rectangular section. Each tube has thin frontal walls that can be thought of as rectangular membranes with pinched edges. "

According to (1), for a steel membrane (E-2.1.10bkg/cm2, P -0.078kg/cm?, is -0.28) with dimensions a-100cm B-10cm, we obtain the value of the frequency of the first harmonic (1-1, K -1): 1 21109 1 1 o p - pra ti pi same 2tO0hz. 2 uoo78y- 028231 100 10 "o

The acoustic emitter was tuned to the same frequency. m

References 1. G.A. Kardashev "Physical methods of intensification of processes of chemical technology", Moscow: Chemistry 1990, p. 205.

From h h - in 2. M.S. Sedov, "Solution of some basic problems of natural oscillations of elastic bodies", Gorky Institute of Engineering and Construction, 1970, p. 47. 1 B 2 5 27 « j LIY u i 4 o Dramas ukkkvuk kya pl i shsh

And DI

- ; 2 "» и и : а я " и яти А DE А

E E t. и и, мя Я и В И з у /г Я и г я - I -i и и Z Й etc. t shle - и I "ШЭ ee dE- ; h.

KE 7 t Y a - her" and и и г и тя , и ги - m - ий я т

Fo --Щ----

Y le (i

Fig. 2

Claims (4)

The formula of the invention 1. The method of liquid flow pasteurization, which involves cavitation treatment of liquid in flow containers, which differs in that, in order to intensify the pasteurization process, an acoustic field with an intensity of 140-160 dB with a frequency equal to the resonance frequency of the flow container is imposed on the flow containers and on the liquid 29 , " and due to elastic vibrations of the walls of the flow container, they create cavitation in the liquid. 2. A device for pasteurizing a liquid flow, which contains a flow capacity, which is characterized by the fact that, in order to intensify the pasteurization process, the flow capacity is made in the form of a multi-element system of flat tubes of rectangular cross-section, connected to the inlet and outlet nozzles for the supply of liquid, placed in a camera where a sound generator is installed. (That) C. The device according to claim 2, which differs in that the dimensions of the flow capacity elements are selected from the condition of ensuring the resonance of the vibrations of the walls of the flow capacity elements and the sound vibrations excited by the sound generator. "-- 4. The device according to claim 2, which is characterized by the fact that the flow capacity tubes are installed in a plane perpendicular to the direction of propagation of sound waves of the generator. t Official bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2004, M 12, 15.12.2004. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. - and? -i - -i (o) (42) 60 b5