RU2371480C1 - Method of producing first fillmass - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to sugar industry, particularly to production of fillmass. The method involves collecting syrup in a vacuum apparatus, thickening the syrup to supersaturation coefficient of 1.25 to 1.30, nucleation by introducing a seed slurry with crystal size of 10 to 20 mcm, growing crystals while maintaining supersaturation coefficient in the metastable region. Fillmass is finally thickened and taken out of the vacuum apparatus. The process of growing crystals begins 5 to 10 s after introduction of the seed slurry in order to retain the initial number of crystals introduced with the seed slurry. The said process is carried out at supersaturation coefficient of 1.05 to 1.10 until achieving crystal content of 10 to 20% of the weight of fillmass. Crystals are then grown while increasing content of dry substances in the massecuite syrup with increase of the supersaturation coefficient from 1.10 to 1.20.

EFFECT: increased coefficient of uniformity of crystals in fillmass, intensification of fillmass production process, prevention of spontaneous crystal formation at the initial stage of growing crystals due to low supersaturation coefficient, value of which is based on long latent period of crystal formation, as well as increased crystal growth rate at the final stage of growing due to gradual increase of the supersaturation coefficient.

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Description

The invention relates to the sugar industry, in particular to the production of massecuite.

The closest technical solution to the proposed one is a method of producing massecuite of the first crystallization, which involves putting syrup into a vacuum apparatus, thickening the syrup to a supersaturation coefficient of 1.25-1.30, planting crystals by introducing seed paste, growing crystals with a supersaturation coefficient of 1.10-1 , 14, the final thickening and unloading of the massecuite from the vacuum apparatus [Sapronov A.R. Technology of sugar production [Text]. - 2nd ed., Rev. and add. - M .: Kolos, 1999. - S.296-302].

The disadvantages of this method are the low coefficient of uniformity of crystals in the massecuite of the first crystallization, a significant duration of the production of massecuite.

The technical result of the invention is to increase the coefficient of uniformity of crystals in the massecuite of the first crystallization and the intensification of the process of producing massecuite.

To achieve the technical result of the invention, a method for producing the massecuite of the first crystallization is provided, which involves putting syrup into a vacuum apparatus, thickening the syrup to a supersaturation coefficient of 1.25-1.30, planting crystals by introducing seed paste with a crystal size of 10-20 microns, crystal growth at maintaining the supersaturation coefficient in the metastable zone, the final thickening and unloading of the massecuite from the vacuum apparatus, while the growth process begins 5-10 s after the introduction of the paste to preserve the original the number of crystals introduced with the paste, and it is carried out at a supersaturation coefficient of 1.05-1.10 to a crystal content of 10-20% by weight of massecuite, then they are grown when the solids content in the intercrystal solution is increased with an increase in the supersaturation coefficient from 1, 10 to 1.20.

The method is as follows.

The required amount of syrup is collected in a vacuum apparatus and concentrated to a labile supersaturation coefficient of 1.25-1.30 in order to prevent the dissolution of crystals introduced with seed paste in areas of a reduced supersaturation coefficient of the vacuum apparatus.

After that, a paste volume containing the required number of crystals 10-20 microns in size is introduced into the vacuum apparatus. The use of paste with a crystal size of 10-20 μm for the factory is due to the high degree of uniformity of the crystals and the possibility of its accurate dosage.

In order to exclude spontaneous crystallization and preserve the initial number of crystals introduced with the paste at a supersaturation ratio of 1.25-1.30, the crystal growth process begins 5-10 seconds after the paste is introduced, which is less than the latent period of crystal formation at a given supersaturation coefficient, and spend it at a supersaturation coefficient of 1.05-1.10 to a crystal content of 10-20% by weight of massecuite. The growth of crystals to their content of 10-20% by weight of massecuite is carried out at a constant dry matter content in the intercrystal solution, corresponding to a supersaturation coefficient of 1.05-1.10, since the purity and saturation coefficient of the intercrystal solution vary slightly. The supersaturation coefficient of 1.05-1.10 ensures the growth of only introduced crystals with paste without spontaneous crystal formation. At a supersaturation coefficient below 1.038, small crystals will dissolve; if the supersaturation coefficient is above 1.10, spontaneous crystallization is possible, since the latent period of crystallization is less than the time interval from this stage to the end of boiling.

After reaching a crystal content of 10-20% by weight of the massecuite, they are grown by increasing the solids content in the intercrystal solution, which is proportional to the decrease in purity and corresponds to an increase in the supersaturation coefficient from 1.10 to 1.20.

With a decrease in the purity of the intercrystal solution, the latent period of crystallization increases, therefore, to maintain a high crystal growth rate, the supersaturation coefficient is gradually increased from 1.10 to 1.20, without fear of spontaneous crystallization.

After this, the massecuite is finally thickened to a solids content of 92-92.5% and unloaded from the vacuum apparatus.

The method of producing massecuite of the first crystallization is illustrated by the following examples.

Example 1 (prototype).

In a vacuum apparatus with a capacity of 60 tons, syrup with a purity of 91.0% is collected. Thicken it to a coefficient of supersaturation of 1.27. After that, 100 cm ^{3 of} seed paste with a crystal size of 12 μm is introduced into the supersaturated solution. Crystal growth is carried out at a supersaturation coefficient of 1.12.

After this, the massecuite is finally concentrated to a solids content of 92.5% and discharged from the vacuum apparatus.

The coefficient of homogeneity of the crystals in the massecuite is 77%. The duration of massecuite is 3.0 hours.

Example 2

In a vacuum apparatus with a capacity of 60 tons, syrup with a purity of 91.0% is collected. Thicken it to a coefficient of supersaturation of 1.27. After that, 100 cm ^{3 of} seed paste with a crystal size of 12 μm is introduced into the vacuum apparatus. The crystal growth begins 5 seconds after the paste is introduced and is carried out at a supersaturation coefficient of 1.06 to a crystal content of 15% by weight of massecuite. Then the build-up is carried out with an increase in the solids content in the intercrystal solution from 81.1% to 83.9%, which corresponds to a decrease in the purity of the intercrystal solution from 89.0% to 80.0% and an increase in the supersaturation coefficient from 1.10 to 1.20 .

After this, the massecuite is finally concentrated to a solids content of 92.5% and discharged from the vacuum apparatus.

The uniformity coefficient of crystals in the massecuite is 85%. The duration of massecuite is 2.5 hours.

As can be seen from the examples, the uniformity coefficient of crystals in the massecuite is increased by 8%, the duration of the production of massecuite of the first crystallization is reduced by 0.5 hours

The proposed method for producing massecuite of the first crystallization allows:

- increase the coefficient of uniformity of crystals in the massecuite;

- intensify the process of producing massecuite;

- to exclude spontaneous crystal formation at the initial stage of crystal growth due to a lower coefficient of supersaturation, the value of which is justified by the duration of the latent period of crystal formation;

- increase the crystal growth rate at the final stage of growth due to the gradual increase in the coefficient of supersaturation.

Claims (1)

A method of producing massecuite of the first crystallization, which involves putting syrup into a vacuum apparatus, thickening the syrup to a supersaturation coefficient of 1.25-1.30, planting crystals by introducing seed paste with a crystal size of 10-20 microns, crystal growth while maintaining the supersaturation coefficient in the metastable zone , the final thickening and unloading of the massecuite from the vacuum apparatus, characterized in that the growth process begins 5-10 seconds after the introduction of the paste to maintain the original number of crystals introduced with the paste, and spend it with a supersaturation coefficient of 1.05-1.10 to a crystal content of 10-20% by weight of massecuite, then they are built up with an increase in the solids content in the intercrystal solution with an increase in the supersaturation coefficient from 1.10 to 1.20.