METHOD FOR PRODUCEING THIN JUICE FOR SUGAR PRODUCTION AND SUGAR PRODUCTION PLANT

Description

State of the art

[0001] The present invention relates to a process for producing thin juice for sugar production, wherein, in a first liming step, milk of lime is added to a raw juice to obtain a mixture of raw juice and milk of lime, and carbon dioxide is then added to the mixture of raw juice and milk of lime in a first carbonation step to obtain a mixture of raw juice and precipitated non-sugar substances, and the mixture of raw juice and precipitated non-sugar substances is subsequently filtered in a first filtration step to obtain a first thin juice. The invention further relates to a process for sugar production.Another object of the invention is a sugar production plant with a juice purification device, which is configured to first add lime milk to a raw juice - in a first liming step - to obtain a mixture of raw juice and lime milk, and then - in a first carbonation step - add carbon dioxide to the mixture of raw juice and lime milk to obtain a mixture of raw juice and precipitated non-sugar substances, and subsequently - in a first filtration step - filter the mixture of raw juice and precipitated non-sugar substances to obtain a first thin juice.

[0002] In industrial sugar production, raw juice is extracted from plants with a high sugar content, such as sugar beets or sugar cane. This can be done through a diffusion process or, in the case of sugar cane, through press extraction. However, the raw juice obtained during extraction still contains a large number of non-sugar substances. These non-sugar substances are partially removed in a purification process called juice purification. In this process, the raw juice is mixed with lime milk, and then carbon dioxide is added to precipitate the lime and non-sugar substances. These are filtered out to obtain a thin juice filtrate. In subsequent processing steps, the thin juice is concentrated, and the sugar it contains is crystallized and separated.

[0003] Sugar production, particularly the juice purification process, requires careful adjustment and, if necessary, fine-tuning of process parameters. It is therefore essential to determine the constituents of the raw juice and / or the thin juice. According to current best practices, this involves taking samples and analyzing them in a laboratory. Sampling and subsequent laboratory analysis involve a certain turnaround time, which must be observed before the analysis results are available and any necessary adjustments, such as modifying process parameters, can be made.

[0004] German patent DE 10 2017 113 132 A1 describes a process for improving yield in sugar production, in which sugar beet pulp and sugarcane juice are produced in an extraction plant using ultrasound. Prior to a first carbonation stage, the sugarcane juice is passed over an ultrasonic unit. The long-chain molecules are broken down by ultrasound, which generates cavitation in the sugarcane juice. A control unit connected to the ultrasonic unit enables the evaluation of sensor data and the control of the ultrasonic unit via corresponding signals as suitable control variables. CA 350 090 A describes the control of CO₂ gas addition during sugar production based on a measurement of the electrical resistance of the treated juice. Disclosure of the invention

[0005] Against this background, the object of the present invention is to enable the tracking of process parameters with lower latency.

[0006] To solve the problem, a method for producing thin juice for the production of sugar according to claim 1 is proposed, wherein In a first liming step, milk of lime is added to a raw juice to obtain a mixture of raw juice and milk of lime. Carbon dioxide is then added to this mixture in a first carbonation step to obtain a mixture of raw juice and precipitated non-sugars. This mixture is then filtered in a first filtration step to obtain a first thin juice. Optionally, milk of lime is added to this first thin juice in a second liming step to obtain a mixture of the first thin juice and milk of lime. Finally, carbon dioxide is optionally added to the first thin juice or the mixture of the first thin juice and milk of lime in a second carbonation step.to obtain a mixture of the first thin juice and precipitated non-sugar substances, and the mixture of the first thin juice and precipitated non-sugar substances is filtered - in a second filtration step - to obtain a second thin juice, , where with at least one first sensor device, initial measurement data concerning the mixture of raw juice and lime milk and / or the mixture of first thin juice and lime milk are recorded during or after the first or second liming step, and / or with at least one second sensor device, second measurement data concerning the mixture of raw juice and precipitated non-sugar substances and / or the mixture of first thin juice and precipitated non-sugar substances are recorded during or after the first or second carbonation step, and / or with at least one third sensor device, third measurement data concerning the first and / or second thin juice are recorded.

[0007] In the inventive method, one or more sensor devices are used to acquire measurement data concerning the respective mixture during or after the first and / or second liming step and / or the mixture during or after the first and / or second carbonation step and / or the first and / or second thin juice. These sensor devices enable the determination of the constituents of the raw juice or thick juice without the need for time-consuming sampling and laboratory analysis. Rather, the inventive method makes it possible to determine the constituents during the ongoing production process without extracting raw juice and / or thin juice. Furthermore, the sensor device(s) enable the analysis and / or control of the juice purification and / or other equipment or process steps in the sugar production process with low latency.

[0008] Preferably, soda or sodium hydroxide is added in the first and / or second carbonation step to precipitate non-sugar substances and adjust the hardness of the thin juice. The first and / or second filtration step can be single-stage or multi-stage.

[0009] According to an advantageous embodiment of the invention, at least one process parameter of the first and / or second liming step and / or the first and / or second carbonation step and / or the first and / or second filtration step is set based on the first and / or second and / or third measurement data. Adjusting the process parameters based on the measurement data acquired by one or more of the sensor devices allows for low-latency adjustment of juice purification process parameters. The at least one process parameter could, for example, be the amount of lime milk added and / or a target pH value and / or a lime milk concentration and / or an amount of precipitated calcium carbonate added. precipitated calcium carbonate, (abbreviated PCC) and / or a sludge juice return quantity and / or an operating parameter of a filter.

[0010] According to the method of the invention, it is provided that the first sensor device includes a first optical image acquisition device and the first measurement data comprise first image data and / or the second sensor device includes a second optical image acquisition device and the second measurement data comprise second image data and / or the third sensor device includes a third optical image acquisition device and the third measurement data comprise third image data.

[0011] Based on the first, second, and / or third image data, it is possible to determine one or more geometric properties of the particles and / or air inclusions contained in the respective raw juice or thin juice. For example, the floc shape of the particles can be determined as a geometric property. Alternatively or additionally, kinetic properties of the particles and / or air inclusions contained in the respective raw juice or thin juice, such as a settling velocity, can be determined based on the first, second, and / or third image data.

[0012] Preferably, the color of a liquid phase of the respective raw juice or thin juice is determined based on the first, second, and / or third image data. Particularly preferably, the amount of lime milk added in the first and / or second liming step is adjusted depending on the determined floc shape of the particles and / or the determined color of the liquid phase. This prevents an undesirable overdose of lime milk. Alternatively or additionally, the amount of dextranase added is adjusted depending on the determined floc shape of the particles and / or the determined color of the liquid phase.

[0013] According to an advantageous embodiment of the method according to the invention, it is provided that the first sensor device includes a first near-infrared spectroscopy device and the first measurement data include a first content measurement of an ingredient and / or the second sensor device includes a second near-infrared spectroscopy device and the second measurement data include a second content measurement of an ingredient and / or the third sensor device includes a third near-infrared spectroscopy device and the third measurement data include a third content measurement of an ingredient.

[0014] One or more near-infrared spectroscopy (NIRS) devices acquire measurement data from which conclusions can be drawn about the constituents of the raw or thin juice being analyzed. Each NIRS device uses a method in which the juice being analyzed is irradiated with electromagnetic radiation in the near-infrared range, for example, in a spectral range of 400 nm to 2,500 nm. This irradiation can excite molecular vibrations in the material under investigation. The electromagnetic radiation in the near-infrared range, e.g., in a spectral range of 400 nm to 2,500 nm, triggered by these molecular vibrations is detected and spectroscopically resolved. The type and / or quantity of constituents in the analyzed materials can be determined from the acquired spectra.The measurement data from the near-infrared spectroscopy device(s) can, for example, indicate the detection of the following constituents or their concentrations: sucrose, fructose, glucose, lactic acid, oxalic acid, oxalates, nitrates, nitrites, pectins, dextrans, and nitrogen. Preferably, the measurement data acquired by the respective near-infrared spectroscopy device can be obtained through multiple measurements from different directions. For this purpose, the respective near-infrared spectroscopy device can be provided with several detectors arranged in different orientations relative to the material under investigation. Such multi-directional measurements allow the constituents to be determined with increased accuracy from the respective measurement data.

[0015] Preferably, the first, second, and / or third measurement data includes a content value of pectins and / or dextrans, and this content value is used to determine the condition of one or more filter devices, such as filter cartridges, used in the filtration step. Preferably, image data from the first, second, and / or third optical image acquisition device are also used to determine the condition. Such determination, and in particular prediction, of the condition can generate a warning indicating that a filter device needs to be replaced or serviced. Consequently, undesirable downtime of the sugar production plant, which can result, for example, from unexpected defects in filter devices, can be avoided.

[0016] Preferably, the first, second, and / or third measurement data includes a content value of the pectins and / or dextrans, and the amount of dextranase to be added is determined based on this content value. Dextranase is typically added to break down dextran, which can hinder the filtration and crystallization of the sugar.

[0017] An advantageous embodiment of the invention provides that the first sensor device has a first nitrogen sensor and the first measurement data include a first nitrogen concentration and / or the second sensor device has a second nitrogen sensor and the second measurement data include a second nitrogen concentration and / or the third sensor device has a third nitrogen sensor and the third measurement data include a third nitrogen concentration.

[0018] The measured nitrogen concentration(s) enable the determination of quality parameters, particularly those relating to the color of the raw juice or thin juice. The nitrogen concentration(s) can be used to predict color formation in subsequent process steps following juice purification and / or to adjust process parameters in subsequent sugar production processes following juice purification.

[0019] According to an advantageous embodiment of the invention, the third sensor device comprises a turbidity and / or color sensor, and the third measurement data includes a turbidity and / or color reading. Based on the turbidity and / or color reading, conclusions can be drawn about the quality of the thin juice. Preferably, a process parameter of the first and / or second filtration step is adjusted depending on the turbidity and / or color reading, for example, an operating parameter of a filter.

[0020] According to an advantageous embodiment of the method, it can alternatively or additionally be provided that the third sensor device comprises a Brix sensor and that the third measurement data includes a sugar content. Brix measurement is the determination of the dry matter content. The purity of the sugar solution can be determined by combining the two measurement methods.

[0021] One design has been identified as advantageous in which the first sensor device is arranged in a first bypass line into which the mixture of raw juice and lime milk or the mixture of first thin juice and lime milk is introduced during or after the first or second liming step, and a stagnant mixture is produced to acquire the first measurement data, and / or the second sensor device is arranged in a second bypass line into which the mixture of raw juice and precipitated non-sugar substances or the mixture of first thin juice and precipitated non-sugar substances is introduced during or after the first or second carbonation step, and a stagnant mixture is produced to acquire the second measurement data, and / or the third sensor device is arranged in a third bypass line into which the first or second thin juice is introduced and a stagnant thin juice is produced to acquire the third measurement data.

[0022] The bypass line can include both an inlet for supplying the juice to be analyzed and an outlet for returning the analyzed juice to the production process after measurement. In this respect, the bypass line forms a path parallel to the regular production flow at a specific point in the production process. Measurements in the stagnant raw or thin juice can be performed with increased accuracy using an optical imaging device and / or a near-infrared spectroscopy device and / or a nitrogen sensor and / or a turbidity and / or color sensor, as interfering effects that can be caused by the flow dynamics of the respective juice are reduced. Furthermore, particularly with regard to a nitrogen sensor, the juice to be analyzed can be pre-treated in the bypass line. For example, the juice can be diluted and / or reagents can be added.

[0023] In this context, it is advantageous to perform a self-cleaning procedure after a measurement has been carried out in the first, second, and / or third bypass line. This self-cleaning procedure can remove, in particular, limescale deposits and / or calcium oxalate. The self-cleaning procedure preferably includes a separation step in which the bypass line is fluidically separated from the regular process flow, for example, by closing an inlet and an outlet of the bypass line. The bypass line can be cleaned with a cleaning medium, especially an acid. The cleaning medium can be introduced and removed via a cleaning medium inlet and outlet that are separate from the inlet and outlet, respectively.

[0024] According to an advantageous embodiment of the method according to the invention, the particle size of particles is determined based on the first measurement data, in particular first image data, and / or the second measurement data, in particular second image data, and / or third measurement data, in particular third image data. The particle size can be specified, for example, by a length and / or a width and / or a cross-sectional area and / or a diameter and / or an equivalent diameter and / or a circumference. The particle size can be a mean particle size or a median particle size, i.e., in particular, a mean value or median of a length and / or a width and / or a cross-sectional area and / or a diameter and / or an equivalent diameter and / or a circumference. Preferably, depending on the determined particle size, at least one process parameter of the first or second liming step and / or the first orsecond carbonation step and / or the first or second filtration step is stopped.

[0025] According to an advantageous embodiment of the method according to the invention, the settling velocity of particles is determined based on the first measurement data, in particular first image data, and / or the second measurement data, in particular second image data, and / or third measurement data, in particular third image data. Preferably, at least one process parameter of the first or second liming step and / or the carbonation step and / or the filtration step is adjusted depending on the determined settling velocity.

[0026] According to an advantageous embodiment of the method according to the invention, a crystal habit of calcium carbonate is determined based on the first measurement data, in particular first image data, and / or the second measurement data, in particular second image data, and / or third measurement data, in particular third image data. Preferably, at least one process parameter of the first or second liming step and / or the first or second carbonation step and / or the first or second filtration step is adjusted depending on the determined crystal habit.

[0027] To solve the aforementioned problem, a method for producing sugar is further proposed, wherein thin juice is produced according to a method described above and sugar is produced from the thin juice in subsequent process steps.

[0028] The process for producing sugar offers the same advantages that have already been described in connection with the process for producing thin juice.

[0029] According to an advantageous embodiment of the sugar production process, at least one process parameter of one of the subsequent process steps is adjusted based on the first, second, and / or third measurement data. Adjusting the process parameters based on the measurement data acquired by one or more of the sensor devices allows for low-latency adjustment of the process parameters of one of the subsequent process steps.

[0030] Preferably, the subsequent process step is a thickening step, a crystallization step, or a separation step. In the thickening step and / or crystallization step, process parameters such as an evaporation temperature during the thickening of the thin juice, a residence time during the thickening of the thin juice, and / or a number of crystallization steps of the thick juice formed during thickening can be set.

[0031] According to an advantageous embodiment of the sugar production process, an extraction step is carried out to obtain the raw juice from sugar beet pulp, wherein at least one process parameter of the extraction step is set depending on the first and / or second measurement data and / or third measurement data. The process parameter of the extraction step can, for example, be an extraction time, which specifies the duration for which the sugar beet pulp remains in the extraction device, and / or an extraction temperature, which specifies the temperature at which the extraction device is operated.

[0032] An advantageous embodiment of the sugar production process involves cutting sugar beet slices from sugar beets using a cutting machine, and adjusting a process parameter of the cutting machine based on the first, second, and / or third measurement data. This allows for low-latency adjustment of the cutting machine's process parameters.

[0033] In addition to the advantageous embodiments explained above, the advantageous embodiments and features described in connection with the process for producing thin juice can also be applied to the process for producing sugar, either alone or in combination.

[0034] The invention further relates to a sugar production plant according to claim 15 with a juice purification device which is configured to In a first liming step, milk of lime is added to a raw juice to obtain a mixture of raw juice and milk of lime, and then, in a first carbonation step, carbon dioxide is added to the mixture of raw juice and milk of lime to obtain a mixture of raw juice and precipitated non-sugars, and the mixture of raw juice and precipitated non-sugars is subsequently filtered in a first filtration step to obtain a first thin juice, optionally, in a second liming step (3'), milk of lime is added to the first thin juice (17) to obtain a mixture of first thin juice and milk of lime (25), and optionally, in a second carbonation step (4'), carbon dioxide is added to the first thin juice (17) or the mixture of first thin juice and milk of lime (25).to obtain a mixture of first thin juice and precipitated non-sugar substances (26) and the mixture of first thin juice and precipitated non-sugar substances (26) is filtered in a second filtration step (5') to obtain a second thin juice (27), characterized by at least a first sensor device for recording first measurement data concerning the mixture of raw juice and lime milk and / or the mixture of first thin juice and lime milk during or after the first or second liming step and / or a second sensor device for recording second measurement data concerning the mixture of raw juice and precipitated non-sugar substances and / or the mixture of first thin juice and precipitated non-sugar substances during or after the first or second carbonation step and / or a third sensor device for recording third measurement data concerning the first or second thin juice,wherein the first sensor device (21) comprises a first optical image acquisition device and the first measurement data comprise first image data and / or the second sensor device (22) comprises a second optical image acquisition device and the second measurement data comprise second image data and / or the third sensor device (23) comprises a third optical image acquisition device and the third measurement data comprise third image data, wherein a geometric property of the particles and / or air inclusions contained in the respective raw juice or thin juice can be determined from the first, second and / or third image data.

[0035] The same advantages can be achieved with the sugar production plant as have already been described in connection with the process for producing sugar.

[0036] The advantageous designs and features described in connection with the processes explained above can be applied to the sugar production plant alone or in combination.

[0037] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of a preferred embodiment with reference to the drawings. The drawings merely illustrate an exemplary embodiment of the invention, which does not limit the inventive concept. Brief description of the characters

[0038] The Fig. 1 shows a process for producing sugar according to a first embodiment of the invention. Fig. 2 shows a method for producing thin juice according to a first embodiment of the invention. Fig. 3 shows a process for producing sugar according to a second embodiment of the invention. Fig. 4shows a method for producing thin juice according to a second embodiment of the invention. Embodiments of the invention

[0039] In the various figures, identical parts are always marked with the same reference symbols and are therefore usually only named or mentioned once.

[0040] The in Fig. 1 The flowchart shown illustrates a first embodiment of a process according to the invention for the production of sugar, which is carried out in a sugar production plant. In this embodiment, sugar beets are used as the starting material. The sugar beets delivered to the sugar production plant are preferably first cleaned, i.e., freed from adhering substances such as soil, sand, or leaves. In a first process step of cutting 1, the sugar beets are cut by a cutting machine to obtain sugar beet pulp 11.

[0041] In a subsequent step following cutting 1, the sugar beet pulp 11 is extracted with water in an extraction unit, also known as juice extraction 2. Optionally, the sugar beet pulp 11 can first be preheated, for example, to a temperature of 60 °C to 80 °C, to make the cell walls more permeable. The actual extraction 2 takes place in a countercurrent process, in which the sugar beet pulp 11 is conveyed or directed through the extraction unit in a countercurrent flow to hot water. The product of extraction 2, in addition to sugar beet pulp residue, is the raw juice 14, which contains almost all the sugar contained in the sugar beets.

[0042] According to a modification of the exemplary embodiment, sugar cane can be used as the starting material. The sugar cane is first cut and can then also be subjected to an extraction step 2 to extract raw juice 14 via a diffusion process. Alternatively, the raw juice can be obtained by press extraction – that is, by pressing the sugar cane or the sugar cane slices.

[0043] In a liming step 3, lime in the form of lime milk is added to the raw juice 14. The lime binds non-sugar substances contained in the raw juice 14. Acids are neutralized and the pH value is raised.

[0044] In the subsequent carbonation step 4, carbon dioxide is introduced into the mixture 15 of raw juice and lime milk. Calcium and other non-sugar substances are bound and precipitate as lime (calcium carbonate). In the subsequent filtration step 5, the lime is then separated, leaving the thin juice 17. The process steps of liming 3, carbonation 4, and filtration 5 are collectively referred to as juice purification. The steps of liming 3, carbonation 4, and filtration 5 can optionally be carried out several times in this sequence, for example, twice in succession, to improve the purification result (see figure). Fig. 3 .

[0045] This is followed by the thickening process step 6, in which the thin juice 17 is thickened in a mostly multi-stage heating process to obtain the thick juice 18.

[0046] In a process step 7, sugar is crystallized from the thick juice 18 at high temperature and reduced pressure. The crystallization 7 preferably comprises several successive crystallization steps. A mixture 19 of thick juice and crystalline sugar, also referred to as magma, is obtained.

[0047] Finally, in a separation step 8, for example in a centrifuge, the granulated sugar is separated.

[0048] In the procedure according to Fig. 1 A juice purification process according to the invention is used, comprising the process steps liming 3, carbonation 4 and filtration 5, which are described below with reference to the illustration in Fig. 2 This will be explained.

[0049] During juice purification, lime milk is first added to the raw juice 14 in liming step 3 to obtain a mixture 15 of raw juice and lime milk. During liming step 3, initial measurement data concerning the mixture of raw juice and lime milk are acquired using a first sensor device 21. For example, liming step 3 can comprise a partial step of pre-liming, and the first sensor device 21 can acquire initial measurement data concerning the raw juice after pre-liming. In such a configuration, the endpoint of pre-liming can be determined by evaluating the measurement data acquired by the first sensor device 21. A partial step of main liming can follow the partial step of pre-liming. Optionally, a second main liming step can be provided.Alternatively, the first sensor device 21 can be arranged after the liming step 3, so that measurement data concerning the mixture 15 of raw juice and lime milk can be recorded.

[0050] The mixture 15 of raw juice and lime milk is then treated with carbon dioxide in carbonation step 4. This causes non-sugar substances to precipitate. The resulting mixture 16 of raw juice and precipitated non-sugar substances is measured by a second sensor device 22 to obtain second measurement data concerning the mixture of raw juice and precipitated non-sugar substances after the carbonation step. Alternatively, the second sensor device 22 can be arranged such that measurement data is acquired during carbonation step 4.

[0051] The mixture 16 of raw juice and precipitated non-sugar substances is then filtered in filtration step 5 to obtain the thin juice 17. A third sensor device 23 records further measurement data concerning the thin juice 17.

[0052] In the exemplary embodiment, the first sensor device 21 comprises an optical image acquisition device which acquires initial image data. The optical image acquisition device can, for example, be designed as a camera, in particular as a color camera. The optical image acquisition device of the first sensor device 21 acquires initial image data, based on which the particle size of particles / flakes contained in the raw juice is determined. Alternatively or additionally, the settling velocity of the particles is determined. Furthermore, alternatively or additionally, the flake shape and / or color of the particles is determined. Further alternatively or additionally, the crystal habit of calcium carbonate contained in the raw juice is determined. Depending on the determined values—i.e., the particle size and / or the settling velocity and / or the crystal habit—a process parameter of the liming step is set.For example, the amount of lime milk added and / or a target pH value and / or a lime milk concentration and / or an amount of precipitated calcium carbonate added can be adjusted depending on the determined values. Preferably, the amount of lime milk added and / or an amount of dextranase added is adjusted depending on the determined floc shape and / or color of the particles.

[0053] The second sensor device 22 according to the exemplary embodiment comprises an optical image acquisition device, which acquires second image data, and a near-infrared spectroscopy device, which determines the concentrations of the constituents of the mixture 16 consisting of raw juice and precipitated non-sugar substances. These constituents and their concentrations are as follows: sucrose, fructose, glucose, lactic acid, oxalic acid, oxalates, nitrates, nitrites, pectins, dextrans, and nitrogen. Depending on the determined dextran concentration, the amount of dextranase added during juice purification is controlled. Furthermore, depending on the determined glucose concentration, the extraction time and / or extraction temperature in extraction step 2 is set.Depending on the determined glucose content, an evaporation temperature is set during the thickening 6 of the thin juice 17 and / or a residence time is set during the thickening 6 of the thin juice 17 and / or a number of crystallization steps is set during the crystallization 7 of the thick juice 18.

[0054] Furthermore, based on the determined content of pectins and / or dextrans as well as the image data of the optical image acquisition device of the second sensor device 22, a status indication of the condition of the filter devices used for filtration 5, for example filter candles, can be determined.

[0055] The third sensor device 23 includes a near-infrared spectroscopy device that determines the concentration of constituents in the thin juice 17, as well as a turbidity and / or color sensor and a Brix sensor. The measurement data acquired by the third sensor device 23 enable quality control of the juice purification process 3, 4, 5.

[0056] The in Fig. 3 The flowchart shown illustrates a second embodiment of a process according to the invention for the production of sugar, which is carried out in a sugar production plant. The process according to the second embodiment corresponds to the first embodiment according to Fig. 1with the difference that a two-stage juice purification process 3, 4, 5, 3', 4', 5' is carried out. In a second liming step 3', milk of lime is added to the first thin juice 17 to obtain a mixture of the first thin juice and milk of lime 25. In a second carbonation step 4', carbon dioxide and preferably soda or sodium hydroxide are added to this mixture of the first thin juice and milk of lime 25 to obtain a mixture of the first thin juice and precipitated non-sugar substances 26. This mixture of the first thin juice and precipitated non-sugar substances 26 is then filtered in a second filtration step 5' to obtain a second thin juice 27. The second filtration step 5' is preferably multi-stage, for example, two-stage.

[0057] The two-stage juice purification according to Fig. 3 The following will be illustrated in Fig. 4 explained in more detail.

[0058] In contrast to the juice purification process according to the first embodiment, the juice purification process of the second embodiment includes a further first sensor device 21' which acquires further first measurement data concerning the mixture of first thin juice and lime milk during the second liming step 3'. The further first sensor device 21' preferably comprises an optical image acquisition device which acquires further first image data. The optical image acquisition device can, for example, be designed as a camera, in particular as a color camera. The optical image acquisition device of the further first sensor device 21' determines first image data on the basis of which the particle size of particles contained in the raw juice is determined. Alternatively or additionally, the settling velocity of the particles is determined. Furthermore, alternatively or additionally, the crystal habit of calcium carbonate contained in the raw juice is determined.Depending on the specified values ​​– namely particle size and / or settling velocity and / or crystal habit – a process parameter of the second liming step 3' is adjusted. For example, the amount of lime milk added and / or a target pH value and / or a lime milk concentration and / or an amount of precipitated calcium carbonate added can be adjusted depending on the specified values.

[0059] Furthermore, the resulting mixture 26 of first thin juice and precipitated non-sugar substances is detected by a second sensor device 22' to obtain further measurement data concerning the mixture 26 of first thin juice and precipitated non-sugar substances after the carbonation step. Alternatively, the second sensor device 22' can be arranged such that measurement data is acquired during the carbonation step 4'. The second sensor device 22' according to the second embodiment comprises an optical image acquisition device, which acquires further image data, and a near-infrared spectroscopy device, which determines the concentrations of the constituents of the mixture 26 of first thin juice and precipitated non-sugar substances. These constituents and their concentrations are: sucrose, fructose, glucose, lactic acid, oxalic acid, oxalates, nitrates, nitrites, pectins, dextrans, and nitrogen.Depending on the determined dextran content, the amount of dextranase added during juice purification is controlled. Furthermore, depending on the determined glucose content, the extraction time and / or extraction temperature in extraction step 2 is set. Also depending on the determined glucose content, an evaporation temperature is set during the thickening 6 of the second thin juice 27, and / or a residence time is set during the thickening 6 of the second thin juice 27, and / or a number of crystallization steps are set during the crystallization 7 of the thick juice 18. In addition, based on the determined pectin and / or dextrans content and the image data from the optical image acquisition device of the second sensor unit 22', a status indicator for the filter devices used for filtration 5, such as filter cartridges, can be determined.

[0060] A further third sensor device 23' acquires additional third measurement data concerning the second thin juice 27. The third sensor device 23 includes a near-infrared spectroscopy device that determines the content of the second thin juice 27, as well as a turbidity and / or color sensor and a Brix sensor. The measurement data acquired by the further third sensor device 23' enable quality control of the juice purification process 3, 4, 5, 3', 4', 5'.

[0061] A particularly preferred modification of the second embodiment comprises exactly one first sensor device 21 for recording first measurement data concerning the mixture of raw juice and lime milk 15 during or after the first liming step 3, and exactly one second sensor device 22' for recording second measurement data concerning the mixture of first thin juice and precipitated non-sugar substances 26 during or after the second carbonation step 4' and exactly one third sensor device 23' for recording third measurement data concerning the second thin juice 27.

[0062] The above-described methods and systems with the sensor devices 21, 22, 23 enable the analysis and / or control of the juice purification and / or other facilities or process steps in the sugar production process with low latency. Reference symbol list

[0063] 1. Process step "Cutting" 2. Process step "Extraction" 3. Process step "Liming" 4. Process step "Carbonation" (2 stages) 5. Process step "Filtration" 6. Process step "Concentration" 7. Process step "Crystallization" 8. Process step "Separation" 10 Cutting machine 11 Sugar beet pulp 12 Water 13 Sugar beet pulp residue 14 Raw juice 15 Mixture of raw juice and lime milk 16 Mixture of raw juice and precipitated non-sugar substances 17 Thin juice 18 Thick juice 19 Mixture of thick juice and granulated sugar 21 Sensor device 22 Sensor device 23 Sensor device

Claims

1. Method for producing thin juice (17, 27) for the manufacture of sugar, wherein to a raw juice (14) - in a first liming step (3) - milk of lime is first added to obtain a mixture of raw juice and milk of lime (15), and to the mixture of raw juice and milk of lime (15) - in a first carbonation step (4) - carbon dioxide is then added to obtain a mixture of raw juice and precipitated non-sugars (16), and the mixture of raw juice and precipitated non-sugars (16) is subsequently - in a first filtration step (5) - filtered to obtain a first thin juice (17), optionally, to the first thin juice (17) - in a second liming step (3') - milk of lime is added to obtain a mixture of first thin juice and milk of lime (25), and optionally, to the first thin juice (17) or the mixture of first thin juice and milk of lime (25) - in a second carbonation step (4') - carbon dioxide is added to obtain a mixture of first thin juice and precipitated non-sugars (26), and the mixture of first thin juice and precipitated non-sugars (26) - in a second filtration step (5') - is filtered to obtain a second thin juice (27), wherein by means of at least one first sensor device (21), first measurement data relating to the mixture of raw juice and milk of lime (15) and / or the mixture of first thin juice and milk of lime (25) are acquired during or after the first and second liming step (3, 3') respectively, and / or by means of at least one second sensor device (22), second measurement data relating to the mixture of raw juice and precipitated non-sugars (16) and / or the mixture of first thin juice and precipitated non-sugars (26) are acquired during or after the first and second carbonation step (4, 4') respectively, and / or by means of at least one third sensor device (23), third measurement data relating to the first and / or second thin juice (17) are acquired, characterised in that the first sensor device (21) comprises a first optical image acquisition device and the first measurement data comprise first image data, and / or the second sensor device (22) comprises a second optical image acquisition device and the second measurement data comprise second image data, and / or the third sensor device (23) comprises a third optical image acquisition device and the third measurement data comprise third image data, wherein a geometric property of the particles and / or air inclusions contained in the respective raw juice or thin juice is determined on the basis of the first, second and / or third image data.

2. Method according to claim 1, characterised in that at least one process parameter of the first and / or second liming step (3, 3') is set in dependence on the first measurement data and / or the second measurement data and / or the third measurement data.

3. Method according to any of the preceding claims, characterised in that at least one process parameter of the first and / or second carbonation step (4, 4') is set in dependence on the first measurement data and / or the second measurement data and / or the third measurement data.

4. Method according to any of the preceding claims, characterised in that at least one process parameter of the first and / or second filtration step (5, 5') is set in dependence on the first measurement data and / or the second measurement data and / or the third measurement data.

5. Method according to any of the preceding claims, characterised in that the geometric property is a floc shape.

6. Method according to claim 5, characterised in that a colour of a liquid phase of the respective raw juice or thin juice is determined on the basis of the first, second and / or third image data.

7. Method according to any of claims 5 or 6, characterised in that in the first and / or second liming step (3, 3') a milk of lime addition quantity is set in dependence on the determined floc shape of the particles and / or the determined colour of the liquid phase, and / or that an addition quantity of dextranase is set in dependence on the determined floc shape of the particles and / or the determined colour of the liquid phase.

8. Method according to any of the preceding claims, characterised in that the first sensor device (21) comprises a first near-infrared spectroscopy device and the first measurement data comprise a first content specification of a constituent, and / or the second sensor device (22) comprises a second near-infrared spectroscopy device and the second measurement data comprise a second content specification of a constituent, and / or the third sensor device (23) comprises a third near-infrared spectroscopy device and the third measurement data comprise a third content specification of a constituent.

9. Method according to any of the preceding claims, characterised in that the first, second and / or third measurement data comprise a content specification of pectins and / or dextrans, wherein on the basis of the content specification of pectins and / or dextrans a condition indication relating to a condition of one or more filter devices, for example filter candles, used in the filtration step is determined.

10. Method according to any of the preceding claims, characterised in that the first sensor device (21) comprises a first nitrogen sensor and the first measurement data comprise a first nitrogen concentration, and / or the second sensor device (22) comprises a second nitrogen sensor and the second measurement data comprise a second nitrogen concentration, and / or the third sensor device (23) comprises a third nitrogen sensor and the third measurement data comprise a third nitrogen concentration.

11. Method according to any of the preceding claims, characterised in that the third sensor device (23) comprises a turbidity and / or colour sensor and the third measurement data comprise a turbidity value and / or a colour value.

12. Method according to claim 11, characterised in that a process parameter of the first and / or second filtration step (5, 5') is set in dependence on the turbidity value and / or the colour value.

13. Method according to any of the preceding claims, characterised in that the third sensor device (23) comprises a Brix sensor and the third measurement data comprise a sugar content.

14. Method for the manufacture of sugar, wherein thin juice (17, 27) is produced according to a method according to any of the preceding claims, and sugar is produced from the thin juice (17, 27) in subsequent process steps, wherein at least one process parameter of one of the subsequent process steps is set in dependence on the first measurement data and / or the second measurement data and / or the third measurement data, the subsequent process step being a thickening step (6) or a crystallisation step (7) or a separation step (8); and / or wherein for the provision of the raw juice (14) an extraction step (2) is carried out to obtain the raw juice (14) from sugar beet cossettes (11), wherein at least one process parameter of the extraction step is set in dependence on the first measurement data and / or the second measurement data and / or the third measurement data.

15. Sugar production plant having a juice purification device configured to add to a raw juice (14) - in a first liming step (3) - milk of lime first, to obtain a mixture of raw juice and milk of lime (15), and add to the mixture of raw juice and milk of lime (15) - in a first carbonation step (4) - carbon dioxide, to obtain a mixture of raw juice and precipitated non-sugars (16), and subsequently filter - in a first filtration step (5) - the mixture of raw juice and precipitated non-sugars (16), to obtain a first thin juice (17), optionally, to the first thin juice (17) - in a second liming step (3') - milk of lime is added to obtain a mixture of first thin juice and milk of lime (25), and optionally, to the first thin juice (17) or the mixture of first thin juice and milk of lime (25) - in a second carbonation step (4') - carbon dioxide is added to obtain a mixture of first thin juice and precipitated non-sugars (26), and the mixture of first thin juice and precipitated non-sugars (26) - in a second filtration step (5') - is filtered to obtain a second thin juice (27), comprising at least one first sensor device (21, 21') for acquiring first measurement data relating to the mixture of raw juice and milk of lime (15) and / or the mixture of first thin juice and milk of lime (25) during or after the first and second liming step (3, 3') respectively, and / or at least one second sensor device (22, 22') for acquiring second measurement data relating to the mixture of raw juice and precipitated non-sugars (16) and / or the mixture of first thin juice and precipitated non-sugars (26) during or after the first and second carbonation step (4, 4') respectively, and / or at least one third sensor device (23, 23') for acquiring third measurement data relating to the first and / or second thin juice (17, 27), characterised in that the first sensor device (21) comprises a first optical image acquisition device and the first measurement data comprise first image data, and / or the second sensor device (22) comprises a second optical image acquisition device and the second measurement data comprise second image data, and / or the third sensor device (23) comprises a third optical image acquisition device and the third measurement data comprise third image data, wherein a geometric property of the particles and / or air inclusions contained in the respective raw juice or thin juice is determinable on the basis of the first, second and / or third image data.