RU2298038C2 - Diffusion juice refining method - Google Patents

Abstract

FIELD: sugar industry.

SUBSTANCE: method provides for performing preliminary progressive defecation, main defecation, first saturation, filtration, and additional defecation of filtered juice. During the latter defecation, dispersed ozone-air mix having 3-12 g/nm³ ozone is passed through juice. Then second saturation and filtration are performed.

EFFECT: increased refining efficiency and weakened coloration of juice.

1 tbl, 5 ex

Description

The invention relates to the sugar industry and can be used to purify the juices of sugar production.

A known method of purification of diffusion juice, including its progressive predefecation, the main defecation, the first saturation, filtration, the second saturation and filtration (Sapronov A.R. Technology of sugar production. - M .: Kolos, 1999. - S.200-203).

The disadvantages of this method are the insufficiently high cleaning effect and the increased color of the purified juice.

The closest analogue of the proposed method is a method for purifying diffusion juice, providing for its preliminary defecation, basic defecation, processing of the defecated juice with ozonized air in an amount of 0.5-3.0 nm ³ per 1 m ^{3 of} solution, the first saturation, filtration, second saturation and filtration ( SU 595382 A1, C 13 D 3/02, 02/28/1978).

The disadvantage of this method is that the oxidation processes are not limited only to the formation of colorless substances. At the same time, the organic part of the precipitate formed during predefection is oxidized, and the stronger the higher the concentration of ozone in the air, the additional amount of ozone is spent on the oxidation of the precipitated mass, as a result of which part of it passes back into solution. This leads to increased peptization of the sediment and an increase in the color of the juice.

The technical result of the proposed invention is to increase the cleaning effect and reduce the color of the juice.

This technical result is achieved by the fact that in the proposed method for purifying diffusion juice, which provides for progressive pre-defecation, basic defecation, ozonation, first saturation, filtering the juice, second saturation and filtering the juice that has been saturated, additional defecation of the juice that has been juice is carried out before the second saturation and ozonation is carried out during this defecation by blowing through the juice of a dispersed ozone-air mixture with a concentration of ozone in it of 3-12 g / nm ³ .

The method is as follows.

Diffusion juice is directed to progressive predefection to a pH of 10.8-11.2 at a temperature of 54-56 ° C, combined basic defecation with a consumption of lime of 2.0-2.5% by weight of the juice, I saturation at a temperature of 85-90 ° C , the final pH value of 10.8-11.2, separation of the precipitate by filtration, defecation before saturation II for 4-6 minutes at a temperature of 80-85 ° C and lime flow rate of 0.2-0.3% by weight of juice when passing through dispersed ozone-air mixture in a volume ratio of juice - gas 1: 0.5-3.0 with an ozone concentration in the ozone-air mixture of 3-12 g / nm ³ . Next, II saturation is carried out at a temperature of 85-90 ° C to a final pH of 9.0-9.5 and separation of the precipitate by filtration.

When the defecated juice is treated with an ozone-air mixture, monosaccharides are intensively decomposed, the decomposition products of which are oxidized in an alkaline medium to form permanent colorless compounds instead of condensing into high molecular weight coloring substances.

It was also established that ozone has a direct bleaching effect on sugar products, reacting with previously formed molecules of coloring substances. Thus, the oxidation of macromolecular compounds occurs, accompanied by a rupture of carbon chains, which is due to a decrease in color and a decrease in the viscosity of the sugar-containing solution.

In order to increase the quality indicators of cleaning, it is necessary to treat much more pure filtered juice of I saturation with ozone, which also makes it possible to increase the concentration of ozone in the ozone-air mixture without increasing the sediment peptization, which cannot be done under conditions of basic defecation. Thus, without increasing the duration of the processing process, the residual concentration of ozone in the solution increases, which leads to the intensification of the ongoing oxidation and decomposition of non-sugars.

The combined effect of these factors on the juice being purified contributes to an increase in the cleaning effect, a decrease in the color of the juice, and a decrease in the sediment peptization.

The method is illustrated by the following examples.

Example 1. According to the proposed method, take diffusion juice with H = 86.6%, CB = 15.49% and Cx = 13.42%, heat it to 55 ° C, carry out progressive predefection to a final pH of juice 11.2. Then the main defecation is carried out, for which CaO is added to the pre-defecated juice at the rate of 2% by weight of the juice, after which I saturation is carried out to a pH of 11.0. The obtained juice I saturation is filtered, the precipitate is separated. Then conduct additional defecation of the filtered juice by adding 0.2% CaO by weight of juice lasting 5 minutes. In the course of additional defecation, a dispersed ozone-air mixture is blown through the juice at a juice: gas volume ratio of 1: 3 with an ozone concentration of 3 g / nm ³ in the mixture. Then carry out II saturation to a solution pH of 9.0 and the precipitate is separated. Juice II saturation analyze. The analysis data are presented in the table.

Example 2. According to the known method, they take diffusion juice with H = 86.6%, CB = 15.49% and Cx = 13.42%, heat it to 55 ° C, carry out progressive predefection to a final pH of juice of 11.2. Then the main defecation is carried out, for which CaO is added to the pre-defecated juice at the rate of 2% by weight of the juice. During the main defecation, the dispersed ozone-air mixture is blown through the juice at a juice: gas volume ratio of 1: 3 with an ozone concentration of 7 g / nm ³ in the mixture. Then, I saturation is carried out to a pH of 11.0, the juice is filtered, the sediment is separated, additional defecation of the filtered juice is added by adding 0.2% CaO by weight of juice for 5 minutes, II saturation to a solution pH of 9.0 and the sediment is separated by filtration. Juice II saturation analyze. The analysis data are presented in the table.

Example 3. The method is carried out analogously to example 1. The concentration of ozone in the ozone-air mixture is 7 g / nm ³ . Juice II saturation analyze. The analysis data are presented in the table.

Example 4. The method is carried out analogously to examples 1 and 3. The concentration of ozone in the ozone-air mixture is 10 g / nm ³ . Juice II saturation analyze. The analysis data are presented in the table.

Example 5. The method is carried out analogously to examples 1, 3 and 4. The concentration of ozone in the ozone-air mixture is 12 g / nm ³ . Juice II saturation analyze. The analysis data are presented in the table.

The option of cleaning the juice Refined Juice Indicators Purity% Chromaticity, conv. units The cleaning effect,% Example 1 91.14 13.27 37.17 Example 2 (known method) 91.12 13.65 37.02 Example 3 91.30 12.84 38.41 Example 4 91.45 12.10 39.57 Example 5 91.41 12.02 39.27 Note: the purity of diffusion juice is 86.6%.

As can be seen from the table, the most effective is the treatment with an ozone-air mixture during additional defecation of the filtered juice with an ozone concentration of 3-12 g / nm ³ , since this increases the cleaning effect by 2.5%.

The proposed method allows to increase the purity of purified juice by 0.33% and lower its color by 11.9% without increasing ozone consumption compared to the known method.

Claims (1)

A method for purifying diffusion juice, providing for its progressive pre-defecation, basic defecation, ozonation, first saturation, filtering the juice, second saturation and filtering the separated juice, characterized in that prior to the second saturation, additional clarification of the separated juice is carried out and ozonation is carried out during this defecation by blowing through juice of a dispersed ozone-air mixture with an ozone concentration of 3-12 g / nm ^{3 in it} .