SU1564195A1 - Method of rectifying reed raw cotton - Google Patents

Abstract

The invention relates to the sugar industry. The purpose of the invention is to increase the cleaning efficiency of raw cane klerovka. The purification method involves the curing of raw sugar in a cross-casting mixer. At the same time as the raw sugar clovering process, an additional defecation is carried out by injecting calcium hydroxide in an amount of 30-50% of the total consumption for defecation until the dry matter reaches 12-18% in the cleating process while maintaining the PH of the solution during this period 10.8-11 , 2. The klerovka is heated to 80-82 ° C and the main defecation is carried out with calcium hydroxide in the amount of 50-70% of its total consumption equal to 4.0-6.0% by weight of raw sugar. Then the Kirovka is saturized and filtered.

Description

The invention relates to the sugar industry, in particular to the purification of raw cane sugar, upon receipt of white sugar from it.

The aim of the invention is to increase the cleaning efficiency of klerovka cane raw sugar.

The method of purification of cane sugar pa pa raw is carried out as follows.

Cane raw sugar, for example, with DB 97.5%, humidity 0.45%, chromaticity 52 standard units, PB 0.56% and a pH of 6.3 (or a similar composition) is fed to the head of the cleaver; having a trough-shaped form, simultaneously with promos having a CB concentration of 10-22%,

The selection of the woodworking furniture with a CB of 55-58% is carried out from the tail end of the mixer,

Lime milk in the amount of 30-50% of its total consumption is introduced into the head of the crossbar shale at a distance of 0.3-0.4 of its length.

Calcium hydroxide is introduced at the initial time of klerovani simultaneously with raw sugar crystals and promos, taking into account the fact that in the process of lime exposure to raw sugar klerovka, the coagulation process, neutralization, precipitation and decomposition of non-sugars will most fully go through reducing substances, the amount of which can be up to 1% by weight of raw sugar and

coke

over Consequently, to effectively carry out the decomposition process ™ and it is necessary to ensure the most favorable conditions

The main part of the non-sugars and prakm ™ all of the reducing substances in the outer layer of the crystal solution adjacent to the crystal, dissolve first the substances in the film on the surface of the crystals, and then the sugar crystals themselves begin to dissolve into the solution.

By conductometric analysis, for the kinetics of dissolving raw sugar, it has been established that after complete dissolution of the film, the content of CB inter crystal solution is 12–18%, and the fine quality is 78–86%. jn At this point, the main part of the reducing substances is in solution (approximately 30-45% by weight of CBJ, all polymers, up to 90% of coloring substances. The viscosity of a 15% solution at 40 ° C is 1.08 MPa s, and 55% - 11.5 MPa with 11 times more. Consequently, all reactions under the action of lime take place faster.

It was established experimentally that when alkalizing the glued mass, the rate of dissolution of sucrose slows down (when dissolving it is 1.5 times slower than at 5). Thus, the content of CB inter-crystal solution of 12–18% will be achieved within a time sufficient for the purification reactions to take place under the action of milk of lime, Q.

The solubility of lime depends on the temperature. So, at 40 C, its solubility is higher than 4 times as compared with a temperature of 80 ° C. The temperature of the glued mass is about 55-65 C. If the obtained klerovka is heated to 80 ° C, then the amount of dissolved lime will decrease slightly. It will appear in a supersaturated state, which will lead to a deeper defecation and an improvement in the cleaning effect on carbonation. by producing more finely dispersed carbonate.

In order to create pH of the medium sufficient for decomposition of RV under these conditions, it is necessary to inject 1.5-3.0% CaO to the mass of sugar (30-50% of its total amount). The milk of lime is supplied with PS, pH Klerovka at the level of 10.8-11.2, which is automatically controlled by the built-in pH meter electrodes. Lime milk is ceased to be given at the place where the CBI intercrystalline solution has reached a concentration of 12–18%.

Taking into account the relatively low viscosity of the crystal solution with a CB of 12-18%, its pH must be maintained at the level of 10.6-11.8. With a single injection of lime, its concentration gradually decreases due to the interaction with the PB of the solution. This decrease in CaO concentration is enhanced by increasing the amount of dissolved PB. Therefore, a progressive supply of lime is necessary to maintain the ratios of PB and CaO concentrations at an optimum level. At the same time, at the end of the dissolution of the film, the lime feed rate is reduced, but the pH of the medium is maintained at 10.8-1.2.

The proposed method allows to achieve a more complete purification of raw sugar, reduce the loss of sugar from decomposition under the action of a very alkaline environment, as well as the loss of sugar from microbiological decomposition. Initial lime feed of 0.3-0.5% of the total consumption allows maintaining the alkaline environment of raw sugar klerovka, which negatively affects the development of microflora in the bonding process and in the supply path of the glued mass of raw sugar to further purification

In this case, there is no need for preliminary alkalization of the cavities and their treatment with formalin, which, being a non-sugar, reduces the yield of crystalline sugar and contributes to the increase in color.

When implementing the proposed method, the defecation in a clearing mixer takes place at 55-65 ° C (prototype - 80-82 ° C), which leads to more complete solubility of lime, and hence to an increase in the efficiency of the decomposition process. It also reduces the possibility of sucrose decomposition.

Further, the clearing process takes place without changes. The obtained woodworking furniture is heated to 80-82 ° C and fed into a container, where the remaining amount of milk of lime is added (50-70% of the total consumption, 4-6% by weight,

5I5

raw sugar). The main defecation is carried out for 5-6 minutes at a pH of 11.5-11.7. Next, klerovka comes to saturation, which lead to a pH of 9.0-9.2. The graded Kirovka is fed to the filter and analyzed. In the filtrate, CE, DB, C, PB are determined.

In parallel, cleaning is carried out according to a known method, according to which raw sugar is glued at 55-65 ° C with a rinse to CB 55-58% with preliminary alkalinization - and processing with formalin, heated to 80-82 ° C, treated with lime milk for 8 -10 minutes in the amount of 4-6% by weight of raw sugar; pH defecation 11.5-11.7. Defaced Kirovka is saturized to a pH of 9.0-9.2, filtered and analyzed

Example, Cane raw sugar (Cx 97.5%, CB 99.5%, DB 97.8%, Cv 52 conventional units, PB 0.56%) in an amount of 200 g simultaneously with about CB 22% (270 g) are sent to the head of the crossbar mixer. In the initial stage of bonding, lime milk is added to the mass to be glued in the amount of 30% of its total consumption. The total consumption of lime is 5% by weight of sugar — 10 g of CaO. With a milk density of 1.17 g / cm, 40 ml of milk of lime is necessary. At the first stage of defecation, 13.3 ml of milk of lime (30% of the total consumption) is consumed.

A cleaver mixer is a sectional trough-shaped vessel in which the glued mass moves to the exit with the help of mixing blades. The values of the CB inter-crystal solution are preliminarily determined along the length of the stirrer. 13.3 ml of milk of lime is introduced into the mixer progressively, starting from the initial moment of supplying raw sugar and until the CB reaches an intercrystalline solution of -12%, while milk of lime is introduced in an amount that will ensure the pH of the agitator along the length of the mixer 10 ,eight. After the completion of the addition of milk of lime, the pH of the valve is somewhat reduced. At the outlet of the clearing agitator, get a klerovka with a CB of 55%.

Then, the klerovka is heated in a water bath to 80 ° C and treated with the remaining amount of lime.

I

0 5 0

50

Q 5 0

five

95

Go milk, - - 26t7 mgg (70% of consumption from the consumption). The klerovka is kept at a pH of 11.6 for 5 minutes and is carbonated to a pH of 9.2. The resulting suspension is filtered. The filtrate is characterized by the following quality indicators: CB ™ 52.5%, DB 98.0%, DI 18.8 sr. units, PB 0.3%.

Parallel to the splicing and cleaning of the prototype klerovka. 200 g of raw sugar of the same composition is glued with promos to CB 55%. The wash is alkalized and the treatment is imitated with formalin. Next, the klerovka is heated to 80 ° C and 40 ml of milk of lime (5% CaO to the mass of raw sugar) are defecated for 10 minutes. After a bowel movement, the krovok is saturized to a pH of 9.2 and filtered. Filtered klerovka raw sugar is characterized by the following indicators: ST 52.0%, DB 96.8% Tsv 23.0 used units, PB 0.5%.

As a result of the implementation of this method, DB of klerovka increases by 1.2% in comparison with the prototype, the chromaticity decreases by 20%, the RV content decreases by 40%.

Example 2 The method is carried out in the same manner as described in example 1 with the same starting sugar. At the first stage, 40% of CaO of its total consumption is introduced, i.e. 2% to the mass of raw (16 ml of milk of lime). The addition of lime is carried out until the CB content of the intercrystalline solution of 15%, while the pH of the medium is maintained at a level of about 1.0. Filtered purified klerovka is characterized by the following indicators: ST 53%, DB 98.2%, Color 19.0 sr, PB 0.28%.

Example 3. The method is carried out as described in example 1. The consumption of lime in the first stage was 50% of its total consumption, i.e. 2.5% by weight of raw sugar (20 ml of milk of lime). The addition of lime in the process of clovering is carried out until the CB intercrystalline solution reaches a value of 18% while maintaining the pH at 11.2.

The cleaned krovrovka is characterized with the following indicators: ST 52.0%, DB 98.4%, Tsv 19.6%, PB 0.25%.

EXAMPLE 4 The method is carried out as described in example 1e. Lime consumption in the first stage is 25% of the total, i.e. 1.25% by weight of raw material (10 ml of milk of lime), the addition of lime is carried out, maintaining the pH at 10.5, to achieve a CB intercrystalline solution of 10.0%,

Indicators purified klerovka; JQ CB 52.0%, DB 97aO%, CW -21.0 standard units, PB 0.4%.

Example 5, The method is carried out as described above. Lime consumption at the first stage - 60% of 15 total consumption, i.e. 3% to the mass of raw (24 ml of milk of lime). The pH is maintained at 11.5 to achieve a CB intercrystalline solution of 20% 020.

Cleaning results: CB 53.5%, DB 97.8%, Color 23.0 used units, PB 0.2%.

As can be seen, the optimal flow rate of milk powder in the first stage is 25 defecation. is a consumption rate of 30-50% of the total. An increase in its drive to a greater decrease in the RB content, an increase in the color of CSB of less than 12%, an insufficiently complete decomposition of PB, and with CB more than 18%, the decomposition of sucrose increases. It is also clear from the examples that in the process of clovering, the optimum pH of the inter-crystal solution is 10.8-11.2. Its increase in color contributes to an increase in chromaticity, while its decrease contributes to inadequate distribution of radioactive substances.

Claims (2)

Invention Formula The method of purification of cane raw sugar, including its clogging of the promos, heating of the klerovka, defecation by introducing into the klerovka hydroxa and calcium, saturation and filtration, which, in order to increase the efficiency of the clearing of the nibbling, simultaneously the raw sugar is additionally defecated by injecting calcium hydroxide in the amount of 30-50% of its total consumption for the defecation until the dry matter content reaches 12-18% during the clearing process while maintaining the pH of the solution in shade and This db of purified klerov-30 this period at the level of 10.811, 2, while the consumption of calcium hydroxide for defecation, carried out after heating nippers, is 50-70% of its total consumption, equal to 4-6% by weight of sugar - shit ki Reducing the consumption of lime reduces the cleaning efficiency. The ST of the intercrystalline solution, in which a bowel movement should be carried out, lies in the range of 12-18%. At values A CB of less than 12% does not completely decompose the PB, and with a CB of more than 18%, the decomposition of sucrose increases. It is also seen from the examples that, during the clovering process, the optimum pH of the inter-crystal solution is 10.8-11, 2. Its increase in color contributes to an increase in chromaticity, while its decrease contributes to insufficient resolution of radioactive substances. Invention Formula The method of purification of cane raw sugar, including its clogging of promos, heating of the klerovka, defecation by adding calcium hydroxide to the klerovka, saturation and filtration, which, in order to increase the efficiency of cleaning the nest, simultaneously with the process klerovanyi raw sugar carry out additional defecation by introducing calcium hydroxide in the amount of 30-50% of its total expenditure on defecation until the content of solids in the process of klerovane 12-18% while maintaining the pH of the solution during this on the period at the level of 10.8 11.2, while the consumption of calcium hydroxide for defecation, carried out after heating the woodworking furniture, is 50-70% of its total consumption, equal to 4-6% by weight of raw sugar.