RU2511498C1 - Crystalline white sugar production method - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention relates to food industry. The method envisages fillmass boiling out and crystallisation in two vacuum apparatus, ready fillmasses output into the receptacle fillmass mixer, centrifugation in a filtering batch centrifuge with first runoff separation, sugar crystals washing with second runoff separation and crystalline white sugar discharge. The crystallisation centres are represented by seed fillmass containing 20-30% of crystals sized 0.120-0.160 mm. In the vacuum apparatus, sugar crystals are grown to a size of 0.180-0.220 mm. Then fillmass in an amount of 35-50% is drained into the second apparatus with simultaneous charge of a sulfurated mixture of syrup with melt of first and second crystallisation sugars containing 65-75% of dry substances into the apparatus. Sugar crystals growing in the first and the second vacuum apparatus is performed with systematic intakes of the sulfurated mixture of syrup with melt. In the first and the second apparatus fillmass is respectively condensed to 92.0-92.5% and 93.0-94.0% of dry substances content. Then fillmass is diluted with the first fillmass runoff from the first apparatus, first - prior to discharge, then - in the receptacle fillmass mixer (to 92.0-92.5% of dry substances content); fillmass from the first vacuum apparatus is supplied for centrifugation earlier than fillmass from the second vacuum apparatus, with sugar crystals washing performed during a period of time corresponding to that of the first runoff separation while scouring water flow rate is equal to 0.16-0.26% of the fillmass weight per second.

EFFECT: invention ensures increased output of crystalline white sugar in the process of fillmass boiling-out and centrifugation and crystallisation.

1 ex

Description

The invention relates to the production of sugar and can be used to increase the efficiency of the technology of boiling and centrifugation of massecuite massecuite crystallization in sugar production.

A known method of producing massecuite of the first crystallization, involving boiling it in a vacuum apparatus according to traditional technology up to 94.0-95.0% of dry matter, rocking before lowering the first flow of the massecuite I crystallization, and the ratio of the first outflow and the massecuite is (1-5) : 6.

After unloading from the vacuum apparatus, the massecuite is kept for 20-40 minutes in a crystallizer with a supersaturation of 1.10-1.13. Before centrifugation, the massecuite is re-shaken to a coefficient of supersaturation of the intercrystal solution of 1.01-1.03 by adding the same edema (SU 1402620, C13F 1/02. Publ. 15.06.88 - Bull. No. 22).

The disadvantage of this method (analogue) is that it does not provide the necessary requirements for the formation of crystallization centers, as well as the conditions for their growth when boiling massecuite in vacuum devices, which can not only lead to a deterioration in the quality of crystalline white sugar, but also cause additional losses of sucrose in the food department of the plant.

The closest is a method of sugar production, involving boiling massecuite I crystallization in the first vacuum apparatus, taking part of it and feeding it into the second vacuum apparatus, draining the finished massecuite into the receiving massecuite and centrifuging in a batch filter centrifuge with separation of the first outflow, washing sugar crystals with the separation of the second outflow and the discharge of crystalline white sugar. Sugar crystals of 0.160-0.220 mm in size are used as crystallization centers, which are expanded in a vacuum apparatus with 88.0-89.0% solids in the massecuite.

In the first vacuum apparatus, massecuite is boiled up to 92.0-92.5% of solids, and in the second up to 93.0-94.0% of solids. This massecuite before descent shake the first outflow of massecuite from the first vacuum apparatus to 92.0-92.5% of dry matter. The massecuite from the first apparatus is sent to centrifugation earlier than the massecuite from the second vacuum apparatus.

The washing of sugar crystals is carried out for a time corresponding to the separation of the first outflow at a water flow rate of 0.15-0.22% by weight of massecuite per second (RU 22644710, C13F 1/02. Publ. 22.11.2005. - Bull. No. 32) .

The disadvantage of this method is that it is technically difficult to provide the conditions for introducing ready-made crystallization centers into a vacuum apparatus, completely eliminating the possibility of their coalescence and dissolution in syrup, it is also possible that secondary crystallization centers (“flours”) can form, which may not not only cause additional losses of sucrose during its crystallization, but also worsen the conditions for the separation of massecuite in centrifuges.

The technical result of the claimed method is to increase the yield of crystalline white sugar in the process of boiling and centrifugation of massecuite I crystallization.

This result is achieved by the fact that in the proposed method for the production of crystalline white sugar, which involves boiling the massecuite massecuite I crystallization in the first vacuum apparatus, taking part of it and feeding it into the second apparatus, draining the finished massecuite into the receiving masher and centrifuging in a batch filter centrifuge with separation of the first outflow, washing sugar crystals with separation of the second outflow and unloading crystalline white sugar.

As centers of crystallization, uterine massecuite is used, containing 20-30% of crystals 0.120-0.160 mm in size, prepared in a separate cooling mold (Modern technologies and equipment for sugar beet production. Part 2 / V.O. Shtangeev, V.T. Kober, L. G. Belostotsky et al. - Edited by V.O. Shtangeev. - K.: "Zucor of Ukraine”, 2004. - P.116-117 (320 p.)), Which is fed into the first vacuum apparatus, where they are being built crystals up to 0.180-0.220 mm, withstanding supersaturation of intercrystal solution 1.12-1.15, after which part of this massecuite in the amount of 35-50% is taken in the WTO A swarm apparatus with the simultaneous addition of a sulfitated syrup mixture into it with a grading of sugars II and III of crystallization containing 65-75% solids until the heating surface of the steam chamber is completely closed, sugar crystals are expanded in the first and second vacuum apparatuses by systematic pumping of a sulfitated syrup mixture with klerovka, while maintaining the coefficient of supersaturation of the intercrystal solution in the range of 1.10-1.12 and the massecuite circulation velocity in the vacuum apparatus 0.5-1.5 m / s, in the first vacuum apparatus the massecuite is thickened to 92.0- 93.0% and in the second - up to 93.0-94.0% of solids and this massecuite is shaken by the first outflow of massecuite from the first apparatus, first before descent, and then in the receiving massecuite mixer to 92.0-92.5% of solids, and the massecuite from the first the vacuum apparatus is served for centrifugation earlier than the massecuite from the second apparatus, and the washing of sugar crystals is carried out for a time corresponding to the period of separation of the first outflow, with a wash water flow rate of 0.16-0.26% by weight of the massecuite per second.

The method is as follows.

First, uterine massecuite is prepared in a separate cooling mold (Modern technologies and equipment for sugar beet production. Part 2 / V.O. Shtangeev, V.T. Kober, L.G. Belostotsky and others. - Edited by V.O. Shtangeev. - K.: "Zucor of Ukraine", 2004. - P.116-117 (320 p.)) At the same time, additional requirements for the content of the mother massecuite for the content of crystals in it within 20-30% and the size of the crystals, which should be kept in the range 0.120-0.160 mm. These differences in the technology of producing masterbatch massecuite improve its subsequent boiling in a vacuum apparatus, reduce the risk of sticking and fusion of sugar crystals and positively affect the quality indicators of the finished crystalline white sugar. If the content in the master massecuite is less than 20% or more than 30% of the crystals, the formation of secondary crystallization centers is possible, the crystal growth rate decreases, the thermal loss of sucrose in the process of boiling massecuite I of the product increases.

The requirements for crystal sizes in the range of 0.120-0.160 mm were obtained experimentally: with a size of less than 0.120 mm, the risk of coalescence increases, and with a size of more than 0.160 mm their growth rate decreases, the formation of new crystallization centers is possible and more time is required to reach these crystal sizes in cooling process.

At the end of the process of obtaining the massecuite massecuite, it is sent as a crystalline base to the first vacuum apparatus, where crystals are grown up to 0.180-0.220 mm, withstanding the supersaturation of the intercrystal solution 1.12-1.15. These conditions are necessary to improve the uterine massecuite as a crystalline base when it is boiled not only in the first, but also in the second vacuum apparatus. When the size of the crystals is less than 0.180 mm or more than 0.220 mm, the achievement of the technical result of the invention is deteriorated, which is also due to the possibility of deterioration of their quality. Withstanding the supersaturation of the intercrystal solution in the range 1.12-1.15 allows you to create optimal conditions for the growth of crystals, thereby eliminating their coalescence and the formation of secondary crystallization centers. With a supersaturation of less than 1.12 or more than 1.15, the conditions for the growth of crystals deteriorate, their quality indicators, as well as increase the loss of sucrose in the process of boiling massecuite.

After the process of crystal growth in the uterine massecuite is over, part of it in the amount of 35-50% is taken from the first apparatus into the second with the simultaneous collection of a sulfitated syrup mixture with sugar clarification II and III crystallization containing 65-75% dry matter until the heating surface is completely closed steam chamber. The amount of massecuite taken from the first vacuum apparatus in the range of 35-50% was established experimentally and allows you to create optimal conditions for the process of boiling massecuite I crystallization in parallel in two devices. When selecting massecuite from the first apparatus less than 35 or more than 50% of its total quantity, the technical solution of the claimed invention is not provided.

The introduction into the vacuum apparatus, together with the selected massecuite, of a sulfitated syrup mixture with klerovka containing 65-75% of solids, eliminates the risk of thermal decomposition of sucrose during their collection into the second apparatus. In addition, this allows you to accelerate the preparation of massecuite for boiling in the second apparatus and reduces the possible loss of sucrose in the process of boiling massecuite.

Requirements for the solids content in the range of 65-75% in a sulfitated mixture of syrup with clover can reduce the time of boiling massecuite in the second apparatus and reduce the loss of sucrose from thermal decomposition. When the content is less than 65% or more than 75% of solids, technological conditions for boiling massecuite are worse.

To create optimal conditions for boiling massecuite in the second apparatus, the method involves conducting this process on a systematic pumping of a sulfitated mixture of syrup with clover. In this case, boiling massecuite in the first and second vacuum apparatuses is carried out withstanding the coefficient of supersaturation of the intercrystal solution in the range of 1.10-1.12 and the circulation speed of the massecuite in the vacuum apparatus of 0.5-1.5 m / s.

These results were obtained experimentally and had a positive effect on the quality indicators of sugar, the loss of sucrose and the duration of boiling massecuite. When the values of the coefficient of supersaturation and the speed of circulation of massecuite exceeding the established limits, the technological conditions of boiling worsen. It turned out that in order to maintain the massecuite circulation in the vacuum apparatus in the interval of 0.5-1.5 m / s, it is better to use vacuum apparatuses with mixing devices (circulators).

In the first vacuum apparatus, the massecuite is condensed to 92.0-92.5%, and in the second to 93.0-94.0% of solids, and this massecuite is shaken by the first swelling of the massecuite from the first apparatus, first before descent, and then in the reception room using a mixer to 92.0-92.5% solids.

Boiling massecuite up to 92.0-92.5% of dry matter meets the requirements of standard technology (Instructions for conducting the process. - M .: VNIISP, 1985. - P.234 (372 s). Thickening of boiled massecuite up to 92.0-92 5% of solids creates the necessary conditions for desaccharification of the intercrystal massecuite solution and is considered sufficient by standard technology. However, it is known that it can be depleted more deeply if the massecuite is boiled to a solids content higher than 93% (SU 1402620, C13F 1 / 02. Publish. 06.15.1988. - Bull. No. 22). As follows from this author According to the certificate, boiling massecuite to 94.0-95.0% of dry matter allows it to reduce the water content in it by 2.0-3.0% compared with the requirements of standard technology.However, when the solids content of more than 94% is reached, mobility sharply decreases massecuite, unloading it from the vacuum apparatus and subsequent processing in centrifuges.

When the massecuite contains less than 93% dry matter, the amount of water in it increases, which leads to additional dissolution of sucrose, and therefore, the yield of crystalline sugar from the vacuum apparatus decreases. Boiling in the second massecuite apparatus up to 93.0-94.0% of solids allows a deeper depletion of intercrystal solution in comparison with standard technology, which means that a higher sugar yield is achieved.

Before lowering the massecuite from the second apparatus, it is shaken by the first outflow of the massecuite from the first vacuum apparatus to 92.0-92.5% of dry matter. Swinging of the massecuite by the outflow of the first apparatus is due to its higher quality in comparison with the first outflow of the massecuite from the first vacuum apparatus. In addition, the swaying of the massecuite with the first outflow allows you to make it movable for descent from the apparatus and subsequent separation in centrifuges.

The proposed method allows centrifugation of the first massecuite earlier than the second. Usually in sugar factories for centrifugation of one cooking massecuite takes 50-60 minutes, which is taken into account in the proposed method. After the centrifuge rotor is loaded with massecuite and the separation of the first outflow is completed, sugar crystals are washed for a time corresponding to the period of separation of the first outflow at a water flow rate of 0.16-0.26% by weight of the massecuite per second. These conditions are established empirically and are optimal for this method. At a flow rate of wash water of less than 0.16% by weight of massecuite per second, substandard crystalline white sugar can be obtained, and at a rate of more than 0.26% by weight of massecuite per second, the amount of soluble sugar increases, and, therefore, its output from the centrifuge decreases.

To increase the efficiency of the massecuite centrifugation process and the sugar crystals washing operation in automatic mode, a periodic filter centrifuge can be equipped with a special device for perceiving the mechanical effect of the separated outflow and converting it into a standard output signal (A. Slavyanskiy Centrifugation and its effect on the output and sugar quality. - M.: Publishing complex of MGUPP, 2007. - 180 p.).

Sugar washed and dried to a moisture content of 0.8-1.5% is discharged from the centrifuge and sent to the drying section.

Example. First, uterine massecuite is prepared from syrup with a content of 70% solids in a separate cooling mold according to known technology. The content of crystals in the uterus massecuite withstand 25%, and their size is 0.140 mm

The finished uterine massecuite is taken into the first vacuum apparatus, which makes it possible to obtain 40 tons of massecuite in one boiling cycle, where crystals are grown on a systematic pumping of a sulfitated syrup mixture with sugar cleansing of II and III crystallization up to 0.200 mm, withstanding the supersaturation of intercrystal solution in the range of 1.13 .

Upon completion of the process of crystal growth (formation of a crystalline base), a part of massecuite from the first apparatus in the amount of 40% of its total mass is taken into a second vacuum apparatus with a simultaneous collection of a sulfitated syrup mixture with sugar melting II and III crystallization containing 70% dry substances , where it is boiled, withstanding a supersaturation of 1.11 and a massecuite circulation speed of 1.0 m / s.

In the first apparatus, the massecuite is condensed to 92.3%, and in the second to 93.5% of solids, and this massecuite is shaken by the first outflow of massecuite from the first apparatus, first before descent, and then in the receiving massecuite mixer to 92.0% of solids.

Massecuite from the first apparatus is served for centrifugation earlier than massecuite from the second apparatus for 60 minutes. The massecuite separation process is carried out in automated batch centrifuges of the FNP-125 IT brand with a single load of the centrifuge with a massecuite weighing 700 kg. The washing of white sugar crystals is carried out for a time corresponding to the period of separation of the first outflow, at a flow rate of wash water of 0.20% by weight of massecuite per second.

After washing, the sugar crystals are dried in a centrifugal force field to a moisture content of 0.8% and unloaded from the centrifuge at a rotational speed of its rotor of 115 min ^-1 .

Outflows of massecuite (first and second) from the first and second vacuum apparatuses are sent to the respective collectors, and crystalline white sugar is sent to the drying compartment.

, $${Ч}_{утфI}^2$$

), содержание в них сухих веществ ( $$С{В}_{утфI}^1$$

, $$С{В}_{утфI}^2$$

), средний выход кристаллов сахара из центрифуги для двух утфелей (К_ср, % к массе утфеля), а также средние значения показателей качества кристаллического белого сахара первого и второго утфелей: цветность (ЦВ_сах, усл.ед.), содержание золы (Зол, %), редуцирующих веществ (РВ, %), гранулометрический состав: средний размер кристаллов (Ср, мм), коэффициент неоднородности (Кн, %).To compare the proposed method with the known determine the purity of the massecuite I crystallization in the first and second vacuum devices ( $$H_{\mathrm{at}tfI}^{\mathrm{one}}$$

, $$H_{\mathrm{at}tfI}^2$$

), their dry matter content ( $$\mathrm{FROM}{\mathrm{AT}}_{\mathrm{at}tfI}^{\mathrm{one}}$$

, $$\mathrm{FROM}{\mathrm{AT}}_{\mathrm{at}tfI}^2$$

), An average yield of crystals from the centrifuge sugar massecuite two (K _cp,% by mass massecuite) and the mean values of quality indicators crystalline white sugar massecuite first and second: chromaticity (CV _sah, conv), ash content (Zol ,%), reducing substances (PB,%), particle size distribution: average crystal size (Cf, mm), heterogeneity coefficient (Kn,%).

The research indicators of the proposed method:

- technological indicators of massecuite I crystallization:

; $$С{В}_{утфI}^1=\mathrm{92,1}\%$$

; $${Ч}_{утфI}^2=\mathrm{91,72}\%$$

; $$С{В}_{утфI}^2=\mathrm{92,0}\%$$

; К_ср=48,6%; $$H_{\mathrm{at}tfI}^{\mathrm{one}}=91.81\%$$

; $$\mathrm{FROM}{\mathrm{AT}}_{\mathrm{at}tfI}^{\mathrm{one}}=92.1\%$$

; $$H_{\mathrm{at}tfI}^2=91.72\%$$

; $$\mathrm{FROM}{\mathrm{AT}}_{\mathrm{at}tfI}^2=92.0\%$$

; K _av = 48.6%;

- physico-chemical and granulometric indicators of crystalline white sugar:

CV _sugar = 0.75 conventional units; Zol = 0.028%; PB = 0.037%; CP = 0.76 mm; KN = 27.3%.

In parallel, the production of sugar is carried out by a known method. In the first vacuum apparatus, which allows 40 tons of massecuite to be boiled in one cycle, syrup with a purity of 91.80% purity is collected and concentrated until a supersaturation ratio of 1.22 is reached. Then sugar crystals of 0.180 mm in size are introduced as crystallization centers at the rate of 10 pcs per 1 mm of the surface length of the test glass. Then they are increased when the massecuite contains 88.5% solids. After reaching the required volume of massecuite in the first vacuum apparatus, part of it in an amount of 50% is taken into the second apparatus.

After this, massecuite in the first and second vacuum devices is boiled until filled. Moreover, in the first of them massecuite is boiled up to 92.0% of solids, and in the second - up to 93.5% of solids. In this case, the massecuite from the first apparatus is lowered into the receiving massecuite mixer and centrifuged 60 minutes earlier than from the second vacuum apparatus. In addition, the massecuite in the second vacuum apparatus is shaken before descent to 92.0% solids by the first edema from the first apparatus.

The process of dividing the massecuite into first, second outflows and crystalline white sugar is carried out in automated batch centrifuges FNP-1251T with a single load of the centrifuge rotor with massecuite weighing 700 kg. Centrifuges are equipped with a device that allows you to start washing the sugar crystals at the time of separation of the bulk of the intercrystal solution.

First, massecuite is centrifuged from the first vacuum apparatus. The start of washing is established at the end of the separation time of the first outflow and is carried out for a time corresponding to the separation time of the first outflow, at a flow rate of 0.20% by weight of massecuite per second.

After washing, the sugar crystals are dried in a centrifugal force field to a moisture content of 0.8% and unloaded from the centrifuge at a rotational speed of its rotor of 115 min ^-1 . After 60 minutes, a similar operation is carried out with massecuite from the second vacuum apparatus. The outflows of massecuite (first and second) of the first and second devices are sent to the respective collections, and crystalline white sugar is sent to the drying compartment.

The research indicators of the known method:

- technological indicators of massecuite I crystallization:

; $$С{В}_{утфI}^1=\mathrm{92,2}\%$$

; $${Ч}_{утфI}^2=\mathrm{91,68}\%$$

; $$С{В}_{утфI}^2=\mathrm{92,1}\%$$

; К_ср=48,6%; $$H_{\mathrm{at}tfI}^{\mathrm{one}}=91.78\%$$

; $$\mathrm{FROM}{\mathrm{AT}}_{\mathrm{at}tfI}^{\mathrm{one}}=92.2\%$$

; $$H_{\mathrm{at}tfI}^2=91.68\%$$

; $$\mathrm{FROM}{\mathrm{AT}}_{\mathrm{at}tfI}^2=92.1\%$$

; K _av = 48.6%;

- physico-chemical and granulometric indicators of crystalline white sugar:

CV _sugar = 0.80 srvc .; Zol = 0.039%; PB = 0.045%; Cp = 0.62 mm; Kn = 29.8%.

Thus, from the data shown in the example, it can be seen that the proposed method in comparison with the known method allows to increase the sugar yield after boiling and centrifugation by 1.4% by weight of massecuite or, in addition to obtaining 980 kg of crystalline white sugar, in comparison with the known method. In addition, the resulting crystalline white sugar also has slightly better quality indicators.

Claims (1)

A method for producing sugar, which involves boiling massecuite massecuite I in the first vacuum apparatus, taking part of it and feeding it into the second apparatus, pouring the finished massecuite into the receiving masher and centrifuging in a batch filter centrifuge with separation of the first outflow, washing sugar crystals with separation of the second outflow and the unloading of crystalline white sugar, characterized in that as the centers of crystallization use uterine massecuite containing 20-30% of crystals with a size of 0.120-0.160 mm, prepared in a separate cooling mold, which is fed into the first vacuum apparatus, where sugar crystals are grown up to 0.180-0.220 mm, withstanding supersaturation of the intercrystal solution 1.12-1.15, after which part of this massecuite in the amount of 35-50% is taken into the second the apparatus with the simultaneous collection of a sulfitated syrup mixture in it with the clearing of sugars II and III of crystallization containing 65-75% of dry substances until the heating surface of the steam chamber is completely closed, sugar crystals are built up in the first and second vacuum apparatuses on systematic pumping a sulfitated mixture of syrup with klerovka, while maintaining the coefficient of supersaturation of the intercrystal solution in the range of 1.10-1.12 and the speed of circulation of massecuite in a vacuum apparatus of 0.5-1.5 m / s, in the first apparatus the massecuite is thickened to 92, 0-92.5%, and in the second - up to 93.0-94.0% of solids, and this massecuite is rocked by the first massecuite drain from the first apparatus, first before descent, and then in the receiving massecuite mixer to 92.0-92.5% dry substances, and the massecuite from the first vacuum apparatus is fed to a centrifugation earlier than the massecuite from the second apparatus, and washed Sugar crystals are carried out for a time corresponding to the period of separation of the first outflow, at a flow rate of wash water of 0.16-0.26% by weight of massecuite per second.