Double-barrel type centrifugal device and caramel pigment preparation system comprising double-barrel type centrifugal device

Abstract

The utility model discloses a double-barrel centrifugal device and a caramel pigment preparation system comprising the double-barrel centrifugal device, the double-barrel centrifugal device comprises an inner barrel and an outer barrel, and a cavity for material liquid to flow is formed between the outer wall of the inner barrel and the inner wall of the outer barrel; a material liquid inlet is formed in the upper part of the outer barrel; a stirring mechanism is arranged in the inner barrel; a dispersing plate is arranged at the lower part of the stirring mechanism; through holes communicated with the cavity are distributed in the wall of the lower part of the inner barrel; a light phase liquid outlet and a heavy phase liquid outlet are formed in the upper part of the inner barrel; and the crude caramel pigment liquid is subjected to high-efficiency and low-energy refining. The caramel pigment preparation system comprises a heating tank, a nanofiltration membrane device, the double-barrel centrifugal device, a standing barrel, an Mvr evaporation device and the like. A continuous passage for preparing and storing the caramel pigment is formed among the raw material storage tank, the heating tank, the nanofiltration membrane device, the double-barrel centrifugal device, the standing barrel, the Mvr evaporation device and the caramel pigment product storage tank. And the stability, orderliness and the like of the caramel pigment preparation process are ensured.

Description

Technical Field

[0001] The utility model specifically relates to a double-barrel centrifugal device and a caramel pigment preparation system containing the double-barrel centrifugal device, belonging to the technical fields of comprehensive utilization of xylose mother liquor resources and caramel pigment preparation. Background Art

[0002] In the preparation process of xylose, it includes processes such as de-alkalization of hemicellulose raw materials, acid hydrolysis, decolorization, electrodialysis, ion exchange, evaporation crystallization, centrifugation, etc. Among them, the sources of hemicellulose raw materials mainly include: one is using corncobs as raw materials; the other is using waste alkali liquor containing hemicellulose from chemical fiber factories (such as: CN102643935A, CN109112233A, CN112195209A, and CN110564898A, etc.). Compared with corncobs, the waste alkali liquor containing hemicellulose has advantages in terms of procurement and transportation costs. However, correspondingly, it further involves de-alkalization and desalting treatments and has relatively strict requirements for processes such as decolorization, electrodialysis, ion exchange, evaporation crystallization, and centrifugation. At the same time, a specific waste liquid is formed: xylose mother liquor. Among them, xylose mother liquor is formed in processes such as evaporation crystallization and centrifugation. Xylose mother liquor includes xylose with a concentration of 40 - 50%, mannose with a concentration of 15 - 25%, glucose with a concentration of 8 - 12%, and xylan with a concentration of 8 - 12%. Through practice, it is found that this waste liquid can form caramel pigment after specific processing.

[0003] Generally, caramel pigment is a complex reddish-brown or blackish-brown mixture condensed from sugar raw materials (such as maltose, sucrose, molasses, etc.) during heating and dehydration, and it is a semi-natural food coloring agent widely used in food in China.

[0004] Although the prior art CN216614473U discloses "a system for co-producing xylitol and caramel pigment using xylose mother liquor", which includes a raw material tank, a filter, a nanofiltration membrane device, a first ion exchange device, a chromatographic separation device, a refined hydrogenation component, and a browning reaction component connected in sequence through pipelines, the processes such as ion exchange, chromatographic separation, refinement, and browning reaction involved in it have high requirements for control conditions; and when performing ion exchange treatment, it brings a large amount of COD to the wastewater, thereby significantly increasing the wastewater treatment cost.

[0005] Therefore, there is a need for a device that can better cooperate with the process of preparing caramel pigment from xylose mother liquor, reduce waste liquid discharge, and ensure the purity of caramel pigment. Summary of the Invention

[0006] In order to overcome the deficiencies of the prior art, a double-barrel centrifugal device and a caramel pigment preparation system containing the double-barrel centrifugal device are proposed. In this technical solution, through the setting of the double-barrel centrifugal device, the crude caramel pigment liquid is refined efficiently and with low energy consumption; then, it is arranged in the preparation system, and a continuous passage for the preparation and preservation of caramel pigment is formed among the raw material storage tank, the heating tank, the nanofiltration membrane device, the double-barrel centrifugal device, the static bucket, the Mvr evaporation device and the caramel pigment product storage tank, which can be better coordinated with the caramel pigment preparation process and ensure the stability and orderliness of the caramel pigment preparation process, etc.

[0007] In order to achieve the above technical purpose, the following technical solution is proposed:

[0008] The first object of this technical solution is to provide: a double-barrel centrifugal device, including an inner barrel and an outer barrel sleeved outside the inner barrel. The inner barrel and the outer barrel are arranged on the same central axis, and a cavity for the flow of the material liquid is formed between the outer wall of the inner barrel and the inner wall of the outer barrel;

[0009] The outer barrel is cylindrical and is hermetically arranged. A material liquid inlet is provided at the upper part of the outer barrel;

[0010] The inner barrel is in the shape of a tank body and is hermetically arranged. A stirring mechanism is provided inside the inner barrel, and a dispersion plate is provided below the stirring mechanism; through holes communicating with the cavity are distributed on the wall of the lower part of the inner barrel. A light-phase liquid outlet and a heavy-phase liquid outlet are provided at the upper part of the inner barrel. One end of the light-phase liquid outlet pipe extends towards the central axis direction, and the other end of the light-phase liquid outlet pipe is connected to the static bucket;

[0011] The heavy-phase liquid outlet is located above the light-phase liquid outlet.

[0012] Further, the height-diameter ratio of the inner barrel is 5 to 10:1. Among them, the "height-diameter ratio" specifically refers to the proportional relationship between the height and the inner diameter.

[0013] Further, a maintenance observation hole is provided at the upper part of the inner barrel, which is convenient for the staff to observe the internal situation of the inner barrel for timely maintenance and cleaning, etc.

[0014] Further, a sewage discharge valve is connected to the bottom of the outer barrel, which is convenient for timely discharging the sewage in the outer barrel, thereby ensuring the orderliness and stability of the centrifugation process.

[0015] Further, an installation seat is provided below the outer barrel, and the inner barrel is fixed on the installation seat.

[0016] Further, the stirring mechanism includes a main shaft and stirring blades arranged on the main shaft. The dispersion plate is arranged below the stirring blades; the main shaft extends out of the inner barrel, and the main shaft is connected to the motor through a coupling, and a speed reducer is provided between the coupling and the motor.

[0017] Further, the stirring blades are arranged on the main shaft in a detachable manner, facilitating the maintenance, replacement, and cleaning of corresponding components.

[0018] The second objective of this technical solution is to provide a caramel pigment preparation system containing a double-barrel centrifugal device, including a heating tank, a nanofiltration membrane device, the double-barrel centrifugal device, a static tank, and an Mvr evaporation device. The feed inlet of the heating tank is connected to a raw material storage tank, and the raw material storage tank is connected to the xylose mother liquor outlet in the xylose production system.

[0019] The nanofiltration membrane device is arranged at the rear side of the working station of the heating tank, and the heating tank is connected to the nanofiltration membrane device.

[0020] The double-barrel centrifugal device is arranged at the rear side of the working station of the nanofiltration membrane device, and the cut-off liquid outlet on the nanofiltration membrane device is connected to the double-barrel centrifugal device.

[0021] The static tank is arranged at the rear side of the working station of the double-barrel centrifugal device, and the light-phase liquid outlet of the double-barrel centrifugal device is connected to the static tank.

[0022] The Mvr evaporation device is arranged at the rear side of the working station of the static tank, the static tank is connected to the Mvr evaporation device, and the Mvr evaporation device is connected to the caramel pigment product storage tank.

[0023] A continuous path for the preparation and storage of caramel pigment is formed among the raw material storage tank, the heating tank, the nanofiltration membrane device, the double-barrel centrifugal device, the static tank, the Mvr evaporation device, and the caramel pigment product storage tank.

[0024] Further, the nanofiltration membrane device uses a nanofiltration membrane with a molecular weight below 300.

[0025] Further, a filtrate temporary storage tank is also arranged at the rear side of the working station of the nanofiltration membrane device. The filtrate outlet on the nanofiltration membrane device is connected to the filtrate storage tank, and the filtrate storage tank is connected to the raw material storage tank and / or the heating tank.

[0026] Further, the preparation system further includes a spray drying tower, which is arranged between the Mvr evaporation device and the caramel pigment product storage tank.

[0027] Further, there are three double-barrel centrifugal devices, and the heavy-phase liquid outlet of the upper double-barrel centrifugal device is connected to the feed inlet of the lower double-barrel centrifugal device.

[0028] In this technical solution, the raw material storage tank, the heating tank, the nanofiltration membrane device, the cut-off liquid temporary storage tank, the filtrate temporary storage tank, the double-barrel centrifugal device, the static tank, the Mvr evaporation device, the spray drying tower, and the caramel pigment product storage tank are connected through transfer pumps and pipelines. Moreover, through the settings of transfer pumps, pipelines, pressure monitoring instruments, temperature detection instruments, etc., precise automatic control is achieved.

[0029] In this technical solution, positional relationships such as "external", "between", "upper part", "inner part", "lower part", "one end", "the other end", "above", "bottom", "inside", "below", "on", "outside", "rear side of the work station", etc. are defined according to the actual use situation, which are common terms in this technical field and also common terms for those skilled in the art during actual use.

[0030] Adopting this technical solution brings the following beneficial technical effects:

[0031] First, in the present utility model, a double-barrel centrifugal device is used for centrifugation, which can effectively separate the liquid material (crude caramel pigment liquid) into a heavy-phase liquid and a light-phase liquid, that is, to carry out high-efficiency and low-energy refining to ensure the quality and purity of the subsequent final product caramel pigment.

[0032] Second, in the present utility model, a continuous passage for the preparation and storage of caramel pigment is formed among the raw material storage tank, the heating tank, the nanofiltration membrane device, the double-barrel centrifugal device, the static bucket, the Mvr evaporation device and the caramel pigment product storage tank, which can better cooperate with the caramel pigment preparation process and ensure the stability and orderliness of the caramel pigment preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the structure diagram of the double-barrel centrifugal device in the present utility model;

[0034] Figure 2 It is the top view of the double-barrel centrifugal device in the present utility model;

[0035] Figure 3 It is the equipment layout diagram of the preparation system in the present utility model;

[0036] In the figure, 1 is the raw material storage tank, 2 is the heating tank, 3 is the nanofiltration membrane device, 4 is the intercepted liquid temporary storage tank, 5 is the Mvr evaporation device, 6 is the caramel pigment product storage tank, 7 is the filtrate temporary storage tank, 8 is the double-barrel centrifugal device, 80 is the inner barrel, 81 is the outer barrel, 82 is the cavity, 83 is the inlet for the crude caramel pigment liquid, 84 is the stirring mechanism, 840 is the main shaft, 841 is the stirring blade, 85 is the dispersion plate, 86 is the through hole, 87 is the outlet for the light-phase liquid, 88 is the outlet for the heavy-phase liquid, 9 is the static bucket, 10 is the spray drying tower, 11 is the coupling, 12 is the motor, 13 is the reducer, 14 is the pipe for the light-phase liquid to flow out, 15 is the mounting seat, 16 is the maintenance observation hole, 17 is the sewage discharge valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] The technical solutions in the embodiments of the present utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0038] Embodiment 1

[0039] This embodiment provides a double-barrel centrifuge device 8, as Figure 1-2 shown, which includes an inner barrel 80 and an outer barrel 81 sleeved outside the inner barrel 80. The inner barrel 80 and the outer barrel 81 are arranged on the same central axis. A cavity 82 for the flow of the material liquid is formed between the outer wall of the inner barrel 80 and the inner wall of the outer barrel 81;

[0040] Outer barrel 81: It is cylindrical and is hermetically arranged. A material liquid inlet is provided at the upper part of the outer barrel 81;

[0041] Inner barrel 80: It is in the shape of a tank body and is hermetically arranged. A stirring mechanism 84 is provided inside the inner barrel 80, and a dispersion plate 85 is provided below the stirring mechanism 84; Through holes 86 communicating with the cavity 82 are distributed on the lower wall of the inner barrel 80. A light-phase liquid outlet 87 and a heavy-phase liquid outlet 88 are provided at the upper part of the inner barrel 80. One end of the light-phase liquid outlet pipe 14 extends towards the central axis direction, and the other end of the light-phase liquid outlet pipe 14 is connected to the static barrel 9; The heavy-phase liquid outlet 88 is located above the light-phase liquid outlet 87. Preferably, the height-diameter ratio of the inner barrel 80 is 5-10:1. Among them, the "height-diameter ratio" specifically refers to the proportional relationship between the height and the inner diameter;

[0042] In addition, a maintenance observation hole 16 is provided at the upper part of the inner barrel 80, which is convenient for staff to observe the internal situation of the inner barrel 80 for timely maintenance, cleaning, etc. A sewage discharge valve 17 is connected to the bottom of the outer barrel 81, which is convenient for timely discharging the sewage in the outer barrel 81, thereby ensuring the orderliness and stability of the centrifugation process. An installation seat 15 is provided below the outer barrel 81, and the inner barrel 80 is fixed on the installation seat 15.

[0043] Regarding the installation of the inner barrel 80, specifically, an installation seat 15 is provided below the outer barrel 81, and the inner barrel 80 is fixed on the installation seat 15.

[0044] The double-barrel centrifuge device 8 is used in the process of preparing caramel pigment from xylose mother liquor. Among them, the involved working principles include:

[0045] 1. Using xylose mother liquor (the xylose mother liquor includes xylose with a concentration of 40 - 50%, mannose with a concentration of 15 - 25%, glucose with a concentration of 8 - 12%, and xylan with a concentration of 8 - 12%) as the raw material, heating it to 75 - 85°C, and performing nanofiltration through the nanofiltration membrane device 3 to obtain a retentate and a filtrate. The retentate is a crude caramel pigment solution with a xylose content of 40 - 50 g / L, a xylose concentration of 4 - 5%, and a xylose purity of 25 - 30%.

[0046] 2. The crude caramel pigment solution enters the outer barrel 81 of the double - barrel centrifuge device 8 in a tangential direction. Through a delivery pump, the crude caramel pigment solution obtains an initial centrifugal force rotation speed.

[0047] 3. The crude caramel pigment solution enters the bottom of the outer barrel 81 through the cavity 82, and then enters the inner barrel 80 through the through - hole 86 on the inner barrel 80. Rotating through the stirring mechanism 84 and the dispersion plate 85 inside the inner barrel 80 helps the crude caramel pigment solution rotate inside the inner barrel 80 and form a heavy - phase region, a mixing region, and a light - phase region.

[0048] 4. A light - phase liquid outlet pipe 14 and an impurity heavy - phase outlet are provided at the upper part of the inner barrel 80. Since the height - to - diameter ratio of the inner barrel 80 is 5 - 10:1, during the residence of the crude caramel pigment solution in the inner barrel 80, the light - phase of the semi - refined caramel pigment solution tends to be distributed along the inner diameter of the inner barrel 80 ring, and the heavy - phase impurities tend to be distributed on the inner wall of the inner barrel 80. Therefore, by setting the light - phase liquid outlet pipe 14, the purpose of extracting the caramel pigment solution is finally achieved. Since the inner and outer barrels 81 are designed as sealed tanks, the centrifugal force applied to the outer barrel 81 will push the crude caramel pigment solution to continuously and automatically discharge the corresponding liquids in the light - phase region and the heavy - phase region. Finally, the refining of the crude caramel pigment solution is realized.

[0049] Example 2

[0050] On the basis of Example 1, in this example, the stirring mechanism 84 is further limited to ensure that it can be better coordinated with the inner barrel 80 layout, and at the same time, the refining of the feed liquid is completed efficiently and with high quality.

[0051] The stirring mechanism 84 includes a main shaft 840 and stirring blades 841 provided on the main shaft 840. The dispersion plate 85 is provided below the stirring blades 841. The main shaft 840 extends outward from the inner barrel 80. The main shaft 840 is connected to the motor 12 through a coupling 11, and a speed reducer 13 is provided between the coupling 11 and the motor 12.

[0052] Among them, the stirring blades 841 are provided on the main shaft 840 in a detachable manner, which is convenient for the maintenance, replacement, and cleaning of the corresponding components.

[0053] Example 3

[0054] On the basis of Embodiments 1-2, the present embodiment provides: a caramel pigment preparation system containing a double-barrel centrifuge device 8, as Figure 3 shown, including a heating tank 2, a nanofiltration membrane device 3, the double-barrel centrifuge device 8, a static tank 9 and an Mvr evaporation device 5. The feed inlet of the heating tank 2 is connected to the raw material storage tank 1, and the raw material storage tank 1 is connected to the xylose mother liquor outlet in the xylose production system; the nanofiltration membrane device 3 is arranged at the rear side of the working station of the heating tank 2, and the heating tank 2 is connected to the nanofiltration membrane device 3; the double-barrel centrifuge device 8 is arranged at the rear side of the working station of the nanofiltration membrane device 3, and the cut-off liquid outlet on the nanofiltration membrane device 3 is connected to the double-barrel centrifuge device 8; the static tank 9 is arranged at the rear side of the working station of the double-barrel centrifuge device 8, and the light-phase liquid outlet 87 of the double-barrel centrifuge device 8 is connected to the static tank 9; the Mvr evaporation device 5 is arranged at the rear side of the working station of the static tank 9, the static tank 9 is connected to the Mvr evaporation device 5, and the Mvr evaporation device 5 is connected to the caramel pigment product storage tank 6;

[0055] A continuous path for the preparation and storage of caramel pigment is formed among the raw material storage tank 1, the heating tank 2, the nanofiltration membrane device 3, the double-barrel centrifuge device 8, the static tank 9, the Mvr evaporation device 5 and the caramel pigment product storage tank 6.

[0056] In addition, the raw material storage tank 1, the heating tank 2, the nanofiltration membrane device 3, the cut-off liquid temporary storage tank 4, the filtrate temporary storage tank 7, the double-barrel centrifuge device 8, the static tank 9, the Mvr evaporation device 5, the spray drying tower 10 and the caramel pigment product storage tank 6 are connected through a transfer pump and pipelines, and further, through the settings of transfer pumps, pipelines, pressure monitoring instruments, temperature detection instruments, etc., precise automatic control is realized.

[0057] Embodiment 4

[0058] On the basis of Embodiment 3, in this embodiment, the filtrate obtained by the nanofiltration membrane device 3 is further processed, that is, the corresponding equipment layout is proposed:

[0059] A filtrate temporary storage tank 7 is further arranged at the rear side of the working station of the nanofiltration membrane device 3. The filtrate outlet on the nanofiltration membrane device 3 is connected to the filtrate storage tank, and the filtrate storage tank is connected to the raw material storage tank 1 and / or the heating tank 2. Further reduce the discharge of waste liquid, improve the utilization rate of xylose mother liquor, and at the same time, improve the yield of caramel pigment, etc.

[0060] Embodiment 5

[0061] On the basis of Embodiments 3-4, in this embodiment, in order to prepare caramel pigment powder, that is, the equipment involved is further arranged as follows:

[0062] The preparation system further includes a spray drying tower 10, and the spray drying tower 10 is arranged between the Mvr evaporation device 5 and the caramel pigment product storage tank 6.

[0063] Example 6

[0064] Based on Examples 3 - 5, in this example, in order to prepare caramel pigment powder, the equipment involved is further arranged as follows:

[0065] There are three double - barrel centrifugal devices 8. The heavy - phase liquid outlet 88 of the upper double - barrel centrifugal device 8 is connected to the feed inlet of the lower double - barrel centrifugal device 8. Finally, the recovery of caramel pigment in the heavy - phase impurities is realized, thereby improving the yield of caramel pigment.

[0066] Example 7

[0067] Based on Examples 3 - 6, this example provides: a preparation process of caramel pigment.

[0068] Specifically, it includes the following steps:

[0069] S1: Using xylose mother liquor as raw material, heating it to 75 - 85°C;

[0070] Among them, the xylose mother liquor includes xylose with a concentration of 40 - 50%, mannose with a concentration of 15 - 25%, glucose with a concentration of 8 - 12%, and xylan with a concentration of 8 - 12%;

[0071] S2: Passing the heated material into the nanofiltration membrane device 3, controlling the temperature at 40 - 45°C and the pressure at 28 - 32 bar to obtain a retentate and a filtrate. The retentate is the crude caramel pigment solution;

[0072] Among them, the retentate includes caramel pigment molecules, macromolecular colloids, and heterosaccharides. The xylose content is 40 - 50 g / L, the xylose concentration is 4 - 5%, and the xylose purity is 25 - 30%; the refractive index of the retentate is 15 - 20, and the conductivity of the retentate is 25000 - 30000 μs / cm;

[0073] In the filtrate, the xylose content is 50 - 60 g / L, the xylose concentration is 5 - 6%, and the xylose purity is 55 - 60%; the refractive index of the filtrate is 10 - 13, and the conductivity of the filtrate is 200 - 300 μs / cm;

[0074] In the nanofiltration membrane device 3, a nanofiltration membrane with a molecular weight below 300 is used, which can filter out most components that do not belong to caramel pigment (such as xylose, glucose, etc.), improving the purity of caramel pigment; if the molecular weight is greater than this value, it cannot effectively intercept caramel pigment, causing some caramel pigment to over - react repeatedly and affecting the quality of caramel pigment;

[0075] S3: Using the double - barrel centrifugal device 8 to centrifuge the obtained retentate to obtain a semi - refined caramel pigment solution; then, standing still to obtain a refined caramel pigment solution;

[0076] Among them, the centrifugal rotation speed is 60 - 200 r / min, and the standing time is 10 - 30 min; preferably, three - stage continuous centrifugation is carried out to improve the yield of caramel pigment;

[0077] S4: Under the conditions of a temperature of 65 - 75 °C and a negative pressure of 0.040 - 0.050 MPa, the obtained refined caramel pigment liquid is evaporated and concentrated to a refractive index ≥ 70; then, spray - dried at a temperature of 120 - 150 °C to obtain refined caramel pigment powder.

[0078] The caramel pigment powder obtained as above is detected, and the results are shown in Table 1 below.

[0079]

Claims

1. A double-barrel centrifugal device, characterized in that, It includes an inner barrel (80) and an outer barrel (81) sleeved outside the inner barrel (80). The inner barrel (80) and the outer barrel (81) are arranged on the same central axis. A cavity (82) for the flow of the material liquid is formed between the outer wall of the inner barrel (80) and the inner wall of the outer barrel (81). The upper part of the outer barrel (81) is provided with a material liquid inlet. A stirring mechanism (84) is arranged inside the inner barrel (80), and a dispersion plate (85) is arranged below the stirring mechanism (84). Through holes (86) communicating with the cavity (82) are distributed on the wall of the lower part of the inner barrel (80). The upper part of the inner barrel (80) is provided with a light-phase liquid outlet (87) and a heavy-phase liquid outlet (88). One end of the light-phase liquid outlet pipe (14) extends towards the central axis direction, and the other end of the light-phase liquid outlet pipe (14) is connected to the static barrel (9). The heavy-phase liquid outlet (88) is located above the light-phase liquid outlet (87).

2. The double-barrel centrifugal device according to claim 1, wherein, The height-diameter ratio of the inner barrel (80) is 5-10:

1.

3. The double-barrel centrifugal device according to claim 1, characterized in that, An installation seat (15) is arranged below the outer barrel (81), and the inner barrel (80) is fixed on the installation seat (15).

4. The double-barrel centrifugal device according to claim 1, characterized in that, The stirring mechanism (84) includes a main shaft (840) and stirring blades (841) arranged on the main shaft (840). The dispersion plate (85) is arranged below the stirring blades (841). The main shaft (840) extends outside the inner barrel (80), and the main shaft (840) is connected to the motor (12) through a coupling (11), and a speed reducer (13) is arranged between the coupling (11) and the motor (12).

5. The double-barrel centrifugal device according to claim 4, wherein, The stirring blades (841) are arranged on the main shaft (840) in a detachable manner.

6. A caramel pigment preparation system containing a double-barrel centrifugal device, characterized in that, It includes a heating tank (2), a nanofiltration membrane device (3), a double-barrel centrifugal device (8) described in any one of claims 1-5, a static barrel (9) and an Mvr evaporation device (5). The feed inlet of the heating tank (2) is connected to the raw material storage tank (1), and the raw material storage tank (1) is connected to the xylose mother liquor outlet in the xylose production system. The nanofiltration membrane device (3) is arranged at the rear side of the working station of the heating tank (2), and the heating tank (2) is connected to the nanofiltration membrane device (3). The double-barrel centrifugal device (8) is arranged at the rear side of the working station of the nanofiltration membrane device (3), and the cut-off liquid outlet on the nanofiltration membrane device (3) is connected to the double-barrel centrifugal device (8). The static barrel (9) is arranged at the rear side of the working station of the double-barrel centrifugal device (8), and the light-phase liquid outlet (87) of the double-barrel centrifugal device (8) is connected to the static barrel (9). The Mvr evaporation device (5) is arranged at the rear side of the working station of the static barrel (9), the static barrel (9) is connected to the Mvr evaporation device (5), and the Mvr evaporation device (5) is connected to the caramel pigment product storage tank (6). A continuous passage for the preparation and storage of caramel pigment is formed among the raw material storage tank (1), the heating tank (2), the nanofiltration membrane device (3), the double-barrel centrifugal device (8), the static barrel (9), the Mvr evaporation device (5) and the caramel pigment product storage tank (6).

7. The caramel pigment preparation system containing a double-barrel centrifugal device according to claim 6, characterized in that, The nanofiltration membrane device (3) uses a nanofiltration membrane with a molecular weight below 300.

8. The caramel pigment preparation system containing a double-barrel centrifugal device according to claim 6, characterized in that, A filtrate temporary storage tank (7) is further provided at the rear side of the working station of the nanofiltration membrane device (3). The filtrate outlet on the nanofiltration membrane device (3) is connected to the filtrate storage tank, and the filtrate storage tank is connected to the raw material storage tank (1) and / or the heating tank (2).

9. The caramel pigment preparation system containing a double-barrel centrifugal device according to claim 6, characterized in that, The preparation system further includes a spray drying tower (10), and the spray drying tower (10) is arranged between the Mvr evaporation device (5) and the caramel pigment product storage tank (6).

10. The caramel pigment preparation system containing a double-barrel centrifugal device according to claim 6, characterized in that, There are three of the double-barrel centrifugal devices (8), and the heavy-phase liquid outlet of the upper double-barrel centrifugal device is connected to the feed inlet of the lower double-barrel centrifugal device.

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