Beet juice evaporation and concentration system

Abstract

This utility model discloses a beet juice evaporation and concentration system, including a first-effect falling film evaporator and a second-effect falling film evaporator. The lower part of the first-effect falling film evaporator is connected to a first-effect falling film separator, and the lower part of the second-effect falling film evaporator is connected to a second-effect falling film separator. The secondary steam from the top of the first and second-effect falling film separators is combined and enters a first-stage compressor. After compression, part of the steam is used as a shell-side heat source for the first-effect falling film evaporator, and the other part enters a second-stage compressor for further heating and is then sent to the shell-side of the second-effect falling film evaporator as a heat source. This system adopts a double-effect falling film + two-stage steam recompression process to achieve low-temperature differential multi-pass evaporation, significantly reducing live steam consumption, reducing the number of equipment units and floor space, improving juice quality, and saving investment and operating costs.

Description

Technical Field

[0001] This utility model relates to an evaporation and concentration system, and more particularly to a beet juice evaporation and concentration system, belonging to the field of high-efficiency and energy-saving industrial technology. Background Technology

[0002] Sugar is one of my country's important products, ranking among the top five in the world in annual production, and is an important component of my country's economic development. White sugar production primarily uses sugarcane (tropical / subtropical) and sugar beets (temperate). Sugarcane grows in tropical and subtropical regions, while sugar beets are adapted to temperate climates. Fresh, highly mature sugarcane or sugar beets are selected as raw materials to ensure sugar content and quality.

[0003] The sugar-making process of sugar beets mainly includes washing, crushing, juicing, refining, evaporation, crystallization, and drying. In the evaporation section, multi-effect evaporation is currently the most commonly used evaporation technology.

[0004] Chinese patent CN109355440A discloses a system and process for continuous membrane production of beet sugar. In this process, the evaporation system is designed with five evaporation effects, concentrating the sugar juice through a series of evaporation effects. Throughout the production process, it is necessary to select and adjust appropriate evaporation temperatures to maintain a certain temperature gradient for optimal performance. The drawbacks of this technology are as follows: although membrane treatment increases the sugar juice concentration and reduces the processing requirements of the evaporation system, the evaporation system is essentially still a multi-effect evaporation process. Firstly, it requires five evaporation effects, resulting in a large footprint. Secondly, the first-effect evaporation requires a large amount of steam as an input heat source. Thirdly, the steam from the final effect is of low quality and difficult to utilize, generally being directly condensed, leading to heat waste. Finally, the increased number of devices during production makes operation more complex and increases the risk of malfunction. Utility Model Content

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, and such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0006] In view of the problems existing in the above and / or prior art, this utility model is proposed.

[0007] The purpose of this invention is to overcome the problems existing in the prior art and provide a beet juice evaporation and concentration system that can reduce system energy consumption, reduce the number of equipment, simplify the evaporation system, reduce operation difficulty, improve juice quality, and reduce equipment investment and operating costs.

[0008] To solve the above technical problems, this utility model provides a beet juice evaporation and concentration system, including a first-effect falling film evaporator 1 and a second-effect falling film evaporator 3. The lower part of the first-effect falling film evaporator 1 is connected to a first-effect falling film separator 2, and the lower part of the second-effect falling film evaporator 3 is connected to a second-effect falling film separator 4. The outlet of the beet juice raw material pipe G1 is connected to the first inlet at the upper end of the first-effect falling film evaporator 1 via a first-pass falling film feed pump B1. The first outlet at the lower end of the first-effect falling film evaporator 1 is connected to the second inlet at the upper end of the first-effect falling film evaporator 1 via a second-pass falling film feed pump B2. The second outlet at the lower end of the first-effect falling film evaporator 1 is connected to the third-pass falling film feed pump B2. Feed pump B3 is connected to the third inlet at the top of the first-effect falling film evaporator 1. The third outlet at the bottom of the first-effect falling film evaporator 1 is connected to the fourth inlet at the top of the second-effect falling film evaporator 3 via the fourth-effect falling film feed pump B4. The fourth outlet at the bottom of the second-effect falling film evaporator 3 is connected to the fifth inlet at the top of the second-effect falling film evaporator 3 via the fifth-effect falling film feed pump B5. The fifth outlet at the bottom of the second-effect falling film evaporator 3 is connected to the sixth inlet at the top of the second-effect falling film evaporator 3 via the sixth-effect falling film feed pump B6. The sixth outlet at the bottom of the second-effect falling film evaporator 3 is connected to the beet juice concentrate outlet pipe G3 via the discharge pump B7. The top secondary steam outlets of the first-effect falling film separator 2 and the second-effect falling film separator 4 are both connected to the inlet of the first-stage compressor 5. The outlet of the first-stage compressor 5 is connected to the shell-side steam inlet of the first-effect falling film evaporator 1 and the inlet of the second-stage compressor 6. The outlet of the second-stage compressor 6 is connected to the shell-side steam inlet of the second-effect falling film evaporator 3.

[0009] Furthermore, the shell-side condensate outlets of the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3 are respectively connected to the condensate tank 8, and the outlet of the condensate tank 8 is connected to the condensate return pipe G2 through the condensate pump B8.

[0010] Furthermore, the shell-side vacuum ports of the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3 are respectively connected to the suction port of the vacuum pump group 7 through the non-condensable gas discharge main pipe G4, and the outlet of the vacuum pump group 7 is open to the atmosphere.

[0011] Compared to the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following: 1. The MVR evaporation and concentration process is adopted, which abandons the traditional multi-effect evaporation process. First, it reduces the number of equipment and the system footprint, thus reducing the company's investment costs on land. Second, it can significantly reduce steam consumption. In the traditional multi-effect evaporation process, taking five-effect evaporation as an example, it takes about 0.3 tons of high-quality saturated live steam to evaporate one ton of water. However, this system can achieve zero steam consumption, which can reduce it by up to 100%. The actual consumption increases as the temperature of the sugar juice decreases.

[0012] 2. Sugar syrup is highly sensitive to temperature; it degrades and denatures at high temperatures, resulting in a darker color and decreased quality. Conventional multi-effect evaporation processes require selecting an appropriate temperature gradient. The first stage of evaporation has the highest temperature, necessitating direct heating with live steam, which carries the risk of overheating the syrup and affecting its final quality. This system maintains negative pressure evaporation through a vacuum system, ensuring the temperature remains within acceptable limits throughout the entire evaporation process and guaranteeing syrup quality. Furthermore, compared to high-temperature evaporation, low-temperature evaporation reduces the overall heat demand and energy consumption of the system.

[0013] 3. By adopting falling film evaporation, compared with the traditional evaporator where the sugar juice stays in the heat exchanger for a long time, it can pass through the heat exchanger in one go without staying in the heat exchanger to maintain the corresponding evaporation rate. This greatly reduces the residence time, improves the evaporation efficiency, and avoids the overheating problem that may be caused by prolonged heat exchange.

[0014] 4. A multi-pass falling film evaporator is adopted, which transforms the original single-pass falling film design into multi-pass falling film evaporation, optimizes the single falling film to multiple falling film, and optimizes the single top distribution to multiple distribution. The sugar juice evaporates step by step, which optimizes the problem of uneven liquid distribution on the large top distribution plate of the traditional falling film evaporator and improves the evaporation effect.

[0015] 5. A two-stage compressor design with one large and one small compressor in series is adopted. The steam from the outlet of the first-stage compressor is used for heating in a single-effect multi-pass falling film evaporator, while a portion of the steam is further heated and pressurized by the second-stage compressor before being used for heating in a second-effect multi-pass falling film evaporator. Compared to a conventional MVR design with a single compressor, this system firstly fully utilizes the compressor's temperature rise, significantly reducing the flow rate of the second-stage compressor, lowering the load by approximately 70%, and saving substantial electricity consumption, resulting in annual electricity cost reductions of millions of dollars and significant economic benefits. Secondly, a single high-temperature rise steam compressor requires a gearbox for speed increase, incurring at least 5% losses. Using a low-temperature rise compressor eliminates the need for a gearbox, directly avoiding losses and improving energy utilization. Finally, high-temperature rise compressors operate at high speeds, generating significant noise and exhibiting poor stability, making them less user-friendly for on-site maintenance personnel. This system design uses two low-speed compressors in series, meeting the temperature rise requirements while addressing the shortcomings of traditional solutions.

[0016] 6. This system features a stable, advanced, and efficient control system, automating the entire process of sugar juice production from low to high concentration. The system incorporates monitoring of key parameters such as flow rate, temperature, pressure, and sag at critical locations within the equipment, enabling precise control of the entire system. Corresponding alarms and emergency measures are also set within the control system to ensure safe operation. Full automation reduces on-site manpower requirements and human error, ensuring high-quality sugar juice while lowering production and operating costs. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein: Figure 1 This is a flowchart of the beet juice evaporation and concentration system of this utility model; In the diagram: 1. Single-effect falling film evaporator; 2. Single-effect falling film separator; 3. Double-effect falling film evaporator; 4. Double-effect falling film separator; 5. First-stage compressor; 6. Second-stage compressor; 7. Vacuum pump set; 8. Condensate tank; B1. Single-pass falling film feed pump; B2. Two-pass falling film feed pump; B3. Three-pass falling film feed pump; B4. Four-pass falling film feed pump; B5. Five-pass falling film feed pump; B6. Six-pass falling film feed pump; B7. Discharge pump; B8. Condensate pump; G1. Beet juice concentrate pipe; G2. Condensate recycling pipe; G3. Beet juice concentrate discharge pipe; G4. Non-condensable gas discharge main pipe. Detailed Implementation

[0018] In the following description of this utility model, the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not mean that the device must have a specific orientation.

[0019] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model will be further described below with reference to specific illustrations. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0021] like Figure 1As shown, the beet juice evaporation and concentration system of this utility model includes a first-effect falling film evaporator 1, a first-effect falling film separator 2, a second-effect falling film evaporator 3, a second-effect falling film separator 4, a first-stage compressor 5, a second-stage compressor 6, and a vacuum pump group 7. The tube bundles of the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3 are divided into multiple passes. The lower part of the first-effect falling film evaporator 1 is connected to the first-effect falling film separator 2, and the bottom outlet of the first-effect falling film separator 2 is connected to the first-pass discharge pipe of the first-effect falling film evaporator 1. The lower part of the second-effect falling film evaporator 3 is connected to the second-effect falling film separator 4, and the bottom outlet of the second-effect falling film separator 4 is connected to the fourth-pass discharge pipe of the second-effect falling film evaporator 3.

[0022] The outlet of beet juice stock solution pipe G1 is connected to the inlet of the first-stage falling film feed pump B1. The outlet of the first-stage falling film feed pump B1 is connected to the first-stage feed port at the top of the first-effect falling film evaporator 1. The first-stage discharge port at the bottom of the first-effect falling film evaporator 1 is connected to the inlet of the second-stage falling film feed pump B2. The outlet of the second-stage falling film feed pump B2 is connected to the second-stage feed port at the top of the first-effect falling film evaporator 1 through the second-stage feed pipe. The second-stage discharge port at the bottom of the first-effect falling film evaporator 1 is connected to the inlet of the third-stage falling film feed pump B3. The outlet of the third-stage falling film feed pump B3 is connected to the third-stage feed port at the top of the first-effect falling film evaporator 1 through the third-stage feed pipe. The third-stage discharge port at the bottom of the first-effect falling film evaporator 1 is connected to the inlet of the fourth-stage falling film feed pump B4.

[0023] The outlet of the four-pass falling film feed pump B4 is connected to the fourth-pass feed port at the upper end of the double-effect falling film evaporator 3 via a four-pass feed pipe. The fourth-pass discharge port at the lower end of the double-effect falling film evaporator 3 is connected to the inlet of the five-pass falling film feed pump B5. The outlet of the five-pass falling film feed pump B5 is connected to the fifth-pass feed port at the upper end of the double-effect falling film evaporator 3 via a five-pass feed pipe. The fifth-pass discharge port at the lower end of the double-effect falling film evaporator 3 is connected to the inlet of the six-pass falling film feed pump B6. The outlet of the six-pass falling film feed pump B6 is connected to the sixth-pass feed port at the upper end of the double-effect falling film evaporator 3 via a six-pass feed pipe. The sixth-pass discharge port at the lower end of the double-effect falling film evaporator 3 is connected to the inlet of the discharge pump B7. The outlet of the discharge pump B7 is connected to the beet sugar concentrate discharge pipe G3.

[0024] The top secondary steam outlets of the first-effect falling film separator 2 and the second-effect falling film separator 4 are both connected to the inlet of the first-stage compressor 5. The outlet of the first-stage compressor 5 is connected to the shell-side steam inlet of the first-effect falling film evaporator 1 and the inlet of the second-stage compressor 6. The outlet of the second-stage compressor 6 is connected to the shell-side steam inlet of the second-effect falling film evaporator 3.

[0025] The shell-side condensate outlets of the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3 are connected to the inlet of the condensate tank 8, the outlet of the condensate tank 8 is connected to the inlet of the condensate pump B8, and the outlet of the condensate pump B8 is connected to the condensate return pipe G2.

[0026] The shell-side vacuum ports of the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3 are connected to the suction port of the vacuum pump group 7 through the non-condensable gas discharge main pipe G4, and the outlet of the vacuum pump group 7 is open to the atmosphere.

[0027] The beet juice stock solution from beet juice stock solution pipe G1 has a temperature of approximately 83°C and a concentration of approximately 34%wt. It is fed by a first-stage falling film feed pump B1 to the first stage of a single-effect falling film evaporator 1 for evaporation and concentration. After the first stage of evaporation, the first-stage juice outlet temperature is approximately 84°C, and the juice concentration is approximately 38.6%. This juice is then fed by a second-stage falling film feed pump B2 into the second stage of the single-effect falling film evaporator 1 for further evaporation. The second-stage juice outlet temperature is approximately 84.3°C, and the outlet concentration is approximately 49%. The juice is then fed by a third-stage falling film feed pump B3 into the third stage of the single-effect falling film evaporator 1 for further evaporation. The third-stage juice outlet temperature is approximately 85°C, and the outlet concentration is approximately 55%. Finally, the juice is fed by a fourth-stage falling film feed pump B4 into the fourth stage of a double-effect falling film evaporator 3 for continued evaporation. The fourth-stage sugar juice exits at approximately 86°C with a concentration of approximately 61.6%. It is then fed by the fifth-stage falling film feed pump B5 into the fifth stage of the single-effect falling film separator 2 for further evaporation. The fifth-stage sugar juice exits at approximately 87°C with a concentration of approximately 67%. It is then fed by the sixth-stage falling film feed pump B6 into the sixth stage of the single-effect falling film separator 2 for further evaporation. The sixth-stage exit temperature is approximately 88.5°C with a concentration of approximately 72%. Finally, the sugar juice is discharged from the evaporation system via the discharge pump B7 and the beet juice concentrate discharge pipe G3, for further processing in the subsequent crystallization process.

[0028] The secondary steam generated by the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3 is 82°C. It passes through the first-effect falling film separator 2 and the second-effect falling film separator 4 respectively to separate the entrained sugar juice. The separated sugar juice is returned to its respective falling film evaporator, while the clean secondary steam is collected and enters the first-stage compressor 5 for compression. The first-stage compressor 5 performs work, raising the temperature and pressure of the secondary steam to 90.5°C. At this point, most of the steam is sent to the shell-side steam inlet of the first-effect falling film evaporator 1 as a heat source, while a small portion is sent to the second-stage compressor 6 for further compression, raising the temperature and pressure to 97°C, and then sent to the shell-side steam inlet of the second-effect falling film evaporator 3 as a heat source.

[0029] After heat exchange in the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3, the secondary steam condenses into water. The condensate flows by gravity into the condensate tank 8, and the condensate in the tank is sent to other water use points through the condensate pump B8 and the condensate return pipe G2.

[0030] The sugar syrup contains some non-condensable gases, such as oxygen and carbon dioxide, which are released along with the steam during evaporation. Most of the steam condenses into water in the first-effect falling film evaporator 1 and the second-effect falling film evaporator 3. The remaining non-condensable gases in the system are extracted and discharged by the vacuum pump group 7. At the same time, a negative pressure is established in the system to maintain low-temperature evaporation.

[0031] The above description is merely a preferred embodiment of the present utility model, showing and describing the basic principles, main features, and advantages of the present utility model. It is not intended to limit the scope of patent protection of the present utility model. Those skilled in the art should understand that the present utility model is not limited to the above embodiments. In addition to the above embodiments, the present utility model may have other implementations without departing from the spirit and scope of the present utility model. Various changes and improvements to the present utility model are also possible. All technical solutions formed by equivalent substitutions or equivalent transformations fall within the scope of protection claimed by the present utility model. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents. Technical features not described in the present utility model can be implemented by or using existing technology, and will not be elaborated here.

Claims

1. A beet juice evaporation and concentration system, comprising a first-effect falling film evaporator (1) and a second-effect falling film evaporator (3), wherein the lower part of the first-effect falling film evaporator (1) is connected to a first-effect falling film separator (2), and the lower part of the second-effect falling film evaporator (3) is connected to a second-effect falling film separator (4), characterized in that: The outlet of the beet juice stock solution pipe (G1) is connected to the first inlet of the upper part of the first-effect falling film evaporator (1) via a first-pass falling film feed pump (B1). The first outlet of the lower part of the first-effect falling film evaporator (1) is connected to the second inlet of the upper part of the first-effect falling film evaporator (1) via a second-pass falling film feed pump (B2). The second outlet of the lower part of the first-effect falling film evaporator (1) is connected to the third inlet of the upper part of the first-effect falling film evaporator (1) via a third-pass falling film feed pump (B3). The third outlet of the lower part of the first-effect falling film evaporator (1) is connected to the fourth-pass falling film evaporator (1). The feed pump (B4) is connected to the fourth inlet of the upper part of the double-effect falling film evaporator (3). The fourth outlet of the lower part of the double-effect falling film evaporator (3) is connected to the fifth inlet of the upper part of the double-effect falling film evaporator (3) through the five-stage falling film feed pump (B5). The fifth outlet of the lower part of the double-effect falling film evaporator (3) is connected to the sixth inlet of the upper part of the double-effect falling film evaporator (3) through the six-stage falling film feed pump (B6). The sixth outlet of the lower part of the double-effect falling film evaporator (3) is connected to the beet juice concentrate outlet pipe (G3) through the discharge pump (B7). The top secondary steam outlets of the first-effect falling film separator (2) and the second-effect falling film separator (4) are both connected to the inlet of the first-stage compressor (5). The outlet of the first-stage compressor (5) is connected to the shell-side steam inlet of the first-effect falling film evaporator (1) and the inlet of the second-stage compressor (6). The outlet of the second-stage compressor (6) is connected to the shell-side steam inlet of the second-effect falling film evaporator (3).

2. The sugar beet juice evaporation concentration system according to claim 1, characterized in that: The shell-side condensate outlets of the first-effect falling film evaporator (1) and the second-effect falling film evaporator (3) are respectively connected to the condensate tank (8), and the outlet of the condensate tank (8) is connected to the condensate return pipe (G2) through the condensate pump (B8).

3. The beet juice evaporation and concentration system according to claim 1 or 2, characterized in that: The shell-side vacuum ports of the first-effect falling film evaporator (1) and the second-effect falling film evaporator (3) are connected to the suction port of the vacuum pump group (7) through the non-condensable gas discharge main pipe (G4), and the outlet of the vacuum pump group (7) is open to the atmosphere.

Images