RU2531404C1 - Method for water preparation for food productions - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: method involves water purification from mechanical admixtures by way of filtration, water treatment with pulse ultrasound field with a frequency equal to 22±1.65 kHz, ultrasonic oscillation power equal to nearly 120-200 W, intensity equal to nearly 10-20 W/cm² and exposure lasting 3-5 minutes. Then water is repeatedly filtered and treated with ultraviolet radiation at wave length amounting to 200-250 nm.

EFFECT: drinking water treatment technology simplification combined with simultaneous increase of the degree of water purification from undesirable admixtures and the required quality water obtainment.

2 dwg, 1 tbl, 3 ex

Description

The invention relates to methods for the preparation of drinking water and can be used for the preparation of tap water by food production enterprises, in particular in the production of soft drinks. Known methods for the preparation and purification of water by using ultrasonic treatment.

A known method of preparing drinking water, in which ultrasonic treatment is performed by a field with an intensity of (1 ÷ 70) · 10 ⁴ W / m ² created by a hydrodynamic generator, and at the same time oxygenated gas is supplied to saturate drinking water with oxygen (RU 2333156, C02F 1/34 , declared on 02.15.2006, published on 09.10.2008).

The disadvantages of this method are the high energy consumption, the need to dispose of the generated waste, as well as the limited use, since for a number of food production oxygen saturation of water is undesirable, in particular for non-alcoholic production.

A known method of purifying water from inorganic and organic substances, including pumping purified water through a hydrodynamic emitter in the cavitation mode (RU No. 2333154, C02F 1/34, announced. 04.16.2007, published. 09/10/2008). The method provides for the supply of a gas phase containing ozone with a concentration of more than 10 g / m ³ , the flow from the hydrodynamic emitter into the contact chamber in front of the blocking surface, and the filtration of water from solid suspensions.

The disadvantage of this method is that due to the saturation of the ozone-air mixture, water acquires a high oxidizing ability and becomes corrosive, in addition, ozone is a toxic gas, therefore any use of it requires careful safety monitoring.

Closest to the technological essence of the claimed invention is a method of water treatment, including exposure to electro-hydraulic shock, in which water is simultaneously treated with a pulsed ultrasonic field with a frequency of not more than 1.3 kHz and an intensity of about 37-51 W / cm ² (RU 2301199, C02F 1 / 48, declared on November 28, 2005, published on June 20, 2007).

The disadvantage of this method is its limited functionality due to the focus only on reducing salt deposits, as well as the complexity due to the need for disposal of the resulting waste and the use of special equipment.

The objective of the invention is to simplify the processing technology of drinking water for food production, mainly non-alcoholic production, while increasing the completeness of water purification from undesirable impurities and obtaining water of a given quality (increasing the efficiency of the cleaning process).

This problem is solved in that in a method for preparing water for food production, including purifying water from mechanical impurities by filtration, treating water with a pulsed ultrasonic field, according to the invention, treating water with ultrasonic radiation is carried out at a frequency of 22 ± 1.65 kHz, with an ultrasonic vibration power of 120 -200 W, an intensity of about 10-20 W / cm ² and an exposure of 3-5 minutes, then the water is re-filtered and treated with ultraviolet radiation with a wavelength of 200-250 nm.

The need to ensure high quality drinking water for the production of food products, in particular soft drinks, is due to the fact that even slight deviations in the quality of water can lead to a sharp decrease in the quality of the finished product. The requirements for the quality of drinking water for the production of soft drinks is determined by the technological instructions for water treatment TI 10-5031536-73-90.

Water requirements according to TI-10-5031536-73-10 for the production of soft drinks (optional) Regulated indicator pH 3-6 Hardness, mEq. / L 0.7 Total microbial number (TBC), CFU / ml ≤25

So, the presence of microorganisms in water in quantities higher than permissible can lead to the formation of extraneous odors, deterioration in the taste of the drink, turbidity, and the formation of a precipitate in the finished drink.

The increased overall hardness of the water used can give the drink a salty taste and lead to the formation of sediment.

To adjust the pH of the water, citric acid must be added additionally, which significantly increases the cost of production.

Thus, depending on the sources of water supply and composition, drinking water used for the technological needs of non-alcoholic production should be processed in order to adjust its chemical composition and ensure microbiological purity.

It is known that the effect of ultrasonic vibrations on water leads to changes in its structure, which, in turn, affects the properties and indicators of water quality to varying degrees.

Changes in the structure and properties of water are determined by a number of effects caused by ultrasonic treatment. One of the most powerful effects is cavitation disintegration, which causes the dissociation of a water molecule and the destruction of the substances present in it.

Cavitation is sufficient for energy and a very effective process of water destruction. Cavitational disintegration as a result of exposure to the primary and secondary sounds of the acoustic cavitation field causes the destruction of hydrogen bonds inside the associates of water molecules, which increases its hydration activity.

The chemical effect of ultrasound can be described as follows. Cavitation involves bubbles filled with liquid vapor and / or dissolved volatiles. Gaseous water molecules that fall into the growing microbubbles are destroyed, as during pyrolysis, forming hydroxyl radicals and a proton:

H ₂ O → HO ^- + H ⁺ .

It should be noted that some effects of cavitation disintegration can already act in the absence of cavitation, i.e. the so-called secondary effects of cavitation disintegration occur. So, if water, previously subjected to cavitation treatment, retains an electric charge, due to the nonequilibrium content of ions, before contact with the object, then the effect of the destructive action of hydroxyls becomes “transient” (Shestakov, SD Technology and equipment for processing food media using cavitation disintegration // S.D. Shestakov, O.N. Krasulya, V.I. Bogush, I.Yu. Potoroko.M .: Publishing House "GIORD", 2013. - 152 p.).

The high antibacterial properties of ultraviolet (UV) radiation are known from the literature (see, for example, L.A. Kulsky. Fundamentals of water chemistry and technology. Kiev: Naukova Dumka, 1991). An increase in the bactericidal properties of UV was also established during the preliminary treatment of ultrasonic water, which reduces the amount of suspended particles in water, thereby increasing the effectiveness of UV.

Studies were carried out on the possibility of using ultrasonic treatment in the technology of preparing water for food production, its effect on the main indicators of water quality and its microbiological purity was studied.

In order to establish an effective treatment regime, trial laboratory tests were carried out. For control, a sample of tap water was selected (initial quality indicators: pH - 7.9; hardness - 8.2 mEq / l; OMC - 19 CFU / ml).

To justify the rational regime of ultrasonic exposure, we studied the process of changing the pH, total hardness, and microbial number depending on the reactor power and exposure. Studies have shown that when using the proposed water treatment technology, the pH of the water, the total hardness and the total microbial number are reduced in comparison with the control water sample.

It was found that the pH decreases on average during the processing of ultrasound for 3 minutes by 0.29-0.34 units. from the control value; within 5 min of processing - by 0.34-0.36 units. from the control value. It was determined that the power of ultrasonic vibrations practically does not affect the decrease in pH.

Ultrasonic water treatment leads to a decrease in the values of the total hardness index, on average, by 20% from the initial value when processing with a power of 160 and 200 W for 3 minutes; the impact of ultrasound for 5 min at the indicated power values allows you to reduce the stiffness value by another 5-7%.

The intensity of reducing the total hardness during processing with a power of 120 W for 3 and 5 minutes is significantly lower than the results of water treatment with an ultrasonic power of 160 and 200 W.

The invention is illustrated by images, in which Fig. 1 shows a graph showing the dependence of pH on power and exposure of ultrasonic treatment, and Fig. 2 is a graph showing the dependence of total hardness on power and exposure of ultrasonic treatment.

In addition, the value of the total microbial number (TBC) of water decreases due to the destructive effect of ultrasonic cavitation on the cells of microorganisms.

Determination of the TBC of water showed that the maximum effect is achieved by treating water with a reactor power of 200 W for 5 minutes of exposure — a reduction of TBC by 44%.

The proposed method is as follows.

Water purified from solids by filtration is affected by ultrasonic radiation in the following mode: frequency 22 ± 1.65 kHz, power of ultrasonic vibration 120-200 W, intensity about 10-20 W / cm ² , exposure 3-5 min, then water re-filtered and treated with ultraviolet radiation with a wavelength of 200-250 nm.

As a result, the pH decreases on average by 0.29-0.36 units, the total hardness - by 16-22%, the total microbial number - by 32-44%.

Example 1

Water purified from solids by filtration is subjected to ultrasonic radiation in the following mode: frequency 22 ± 1.65 kHz, power of ultrasonic vibration 160 W, intensity about 10 W / cm ² , exposure 4 min, then water is re-filtered and treated with ultraviolet radiation wavelength of 200 nm.

As a result, the pH decreases on average by 0.32 units, the total hardness - by 18%, the total microbial number - by 38%.

Example 2

It is carried out analogously to example 1, with the following modes: frequency 22 ± 1.65 kHz, reactor power 120 W, intensity of the order of 15 W / cm ² , exposure time 5 min. The wavelength of UV radiation is 225 nm.

As a result, the pH decreases on average by 0.34 units, the total hardness - by 17%, the total microbial number - by 32%.

Example 3

It is carried out analogously to example 1, with the following modes: frequency 22 ± 1.65 kHz, reactor power 200 W, intensity about 15 W / cm ² , exposure 3 min. The wavelength of UV radiation is 250 nm.

As a result, the pH decreases on average by 0.3 units, the total hardness - by 20%, the total microbial number - by 42%.

Thus, the use of the proposed water treatment technology based on ultrasonic exposure for food production, in particular the non-alcoholic industry, allows you to effectively adjust the properties of water in terms of indicators such as pH, total hardness and total microbial number.

Depending on the initial properties of water, the modes of water treatment technology can be adjusted taking into account the proposed examples.

Claims (1)

A method of preparing water for food production, including purifying water from mechanical impurities by filtration, treating water with a pulsed ultrasonic field, characterized in that the water is treated with ultrasonic radiation at a frequency of 22 ± 1.65 kHz, an ultrasonic vibration power of 120-200 W, and an intensity of the order 10-20 W / cm ² and an exposure of 3-5 minutes, then the water is re-filtered and treated with ultraviolet radiation with a wavelength of 200-250 nm.

Images