CN104831002B - A kind of sugar clarification production line - Google Patents

Abstract

A sugar clarification production line includes a mixed juice tank, a horizontal screw centrifuge, a first heating device, a sulfur fumigation device, a second heating device, a multi-stage ceramic membrane ultrafiltration system and a plate and frame filter press connected in sequence. In the present invention, only a small amount of lime and SO ₂ are added in the clarification process of the sugarcane mixed juice. Since the added SO ₂ is less, the sulfur content in the finished sugar is very small, and the color value is low, the purity is high, and the ash content is low, thereby It ensures that the finished sugar can meet the needs of high-end customers. In addition, in the sugarcane juice clarification process, ceramic membrane ultrafiltration is used for clarification. Due to the small membrane resistance caused by scaling on the ceramic membrane, the membrane permeation flux of the ceramic membrane for filtering sugarcane juice is relatively large, and the flux decay rate of the ceramic membrane is slow. , can maintain a high membrane flux filtration, thereby prolonging the membrane cleaning cycle and reducing the frequency of membrane cleaning.

Description

A sugar clarification production line

technical field

The invention relates to the technical field of sugar refining engineering, in particular to a sugar refining clarification production line.

Background technique

my country is the third largest sugar producing country in the world, with an annual output of more than 10 million tons of white granulated sugar. At present, according to different sugar clarification processes, there are mainly two methods for producing farmland white granulated sugar: the first is the sulfurous acid method, and the second is the carbonic acid method. Although these two methods can produce white granulated sugar meeting national quality standards, there are more or less deficiencies in both the sulfurous acid method and the carbonic acid method. The sulfurous acid method adds more _SO2 as a clarifying agent in the clarification process, resulting in more sulfur residues in the finished sugar, which has certain limitations for high-end customers; while the carbonic acid method requires a large amount of lime as a clarifying agent, And produce a large amount of strongly alkaline filter mud that is difficult to handle, which is not conducive to ecological protection. This is also the reason why some domestic sugar factories have adopted the "two-step method" to produce high-quality white sugar in recent years. However, the "two-step method" has a long production process, high equipment investment costs, and high energy consumption, so it cannot be widely used. .

With the development of society and the continuous advancement of science and technology, membrane separation technology, a physical separation process, has attracted widespread attention from sugar producers. Separation membranes can be divided into inorganic membranes and organic membranes according to their manufacturing materials. Based on the advantages of inorganic ceramic membranes such as high mechanical strength, high chemical stability, high temperature resistance, corrosion resistance, oxidation resistance, strong anti-microbial ability, high separation precision and easy cleaning, it is widely considered to be the most suitable for industrial sugar production. membrane material.

According to relevant literature reports, there are sugarcane sugar factories to send the clarified sugarcane juice obtained after mixing juice (sugarcane juice) through adding ash, coarse filtration, and ceramic membrane ultrafiltration to clarify successively to evaporate and boil sugar. This method directly filters sugarcane juice with ceramic membranes to obtain clarified juice, which saves a series of complicated clarification procedures such as sulfur addition, ash addition, and precipitation in the sugar production process, thereby greatly shortening the entire sugar production process. There are many deficiencies: (1) although this method can obtain the sugarcane clarified juice with clear and transparent color and little turbidity, it is difficult to retain some pigments with less molecular weight due to ceramic membrane ultrafiltration, and these small molecular pigments In the sucrose crystallization process, it is a kind of pigment that is easy to attach to the surface of sucrose crystals. Therefore, the white sugar produced by this method has a high color value, and its color value is between 500 and 600IU. It is difficult to achieve the national first-class white sugar color. value (≤150IU); (2) In the traditional sulphite sugar clarification process, although its removal rate of colored substances is small, the SO ₂ introduced by it affects the pigment in the sugar through redox The action of the reaction bleaches it, thereby inhibiting the attachment of small molecular pigments on the surface of sucrose crystals during the sugar crystallization process, and the amino acids and reducing sugars in sugar juice are prone to Maillard reactions to generate Maillard pigments, and Maillard pigments also It is a pigment that is easily attached to the surface of sucrose crystals, and the presence of sulfur can inhibit the occurrence of Maillard reaction. Therefore, the color value of white granulated sugar produced by the traditional sulfite sugar clarification process is better than that of the above-mentioned membrane clarification process. much lower. Therefore, the sugar obtained by this method can only be used as raw sugar, and high-quality sugar can be obtained through further refining, but this must greatly increase the production cost, which is not generally accepted by sugar factories.

In order to process the clarified sugarcane juice obtained by membrane filtration into white sugar with better quality, in the invention patent CN103725802A, the inventor sequentially passes the sugarcane juice through coarse filtration, ceramic membrane fine filtration, organic membrane pre-concentration, ion exchange resin desalination and decolorization , MVR evaporates, concentrates, and crystallizes to obtain refined sugar. Although this method can obtain refined sugar with better quality, it also has many problems: (1) the pH value of sugarcane juice is generally around 5.6, which is acidic, and the inventor has not used milk of lime (or other substances) to The pH of sugarcane juice is adjusted to be around neutral before processing, which will lead to serious conversion loss of sucrose during processing, thereby reducing the recovery rate of sucrose; (2) using organic nanofiltration or organic reverse osmosis membrane to concentrate sugarcane juice, the flux is relatively low Small size, low concentration ratio, and easy pollution, which not only increases the time of sucrose processing, leads to more sucrose conversion, but also increases the investment cost of equipment; (3) The decolorization of ion exchange resin belongs to fine decolorization, and the color value of sugarcane juice is generally in the 1500～2500IU, the color value is high, which not only increases the load of ion exchange resin but also reduces the life of ion exchange resin, and the resin is polluted quickly and regeneration is difficult; (4) the conductivity of sugarcane juice is 3000～6000us/cm In order to remove the salt in sugarcane juice, the load of desalting resin will be larger, and the investment cost of equipment will be larger. Moreover, although the conductivity of sugarcane juice is larger, it has little impact on the sugar production process, and it is not necessary to spend a lot of money to convert it (5) The evaporation section uses steam to heat the cane juice, so that after the cane juice is boiled, the water evaporates to achieve the purpose of concentration. At present, sugar factories generally use a five-effect pressure vacuum evaporation system to change the water that needs to be evaporated from clear juice to syrup. It is about 65% to 80%. It needs to consume more steam, and also produces a large amount of secondary steam (juice steam). The temperature of the secondary steam is still high, which can be used for heating juice or boiling sugar. Therefore The evaporation section is not only a consumer of steam, but also a supply station of low-pressure steam. At the same time, it also supplies hot water to other departments of the sugar factory, so it is called the second boiler of the sugar factory. The MVR evaporator replaces the five-effect pressure of the traditional sugar production process. Although vacuum evaporation can obtain a lower evaporation temperature, thereby obtaining better quality syrup, but the MVR evaporation temperature is lower, and the pressure and temperature of the secondary steam generated by it are much lower than the five-effect pressure vacuum evaporation, which can be used The efficiency is low. If the exhaust steam from the boiler cooling and decompression is directly used as heating or sugar cooking steam, the energy consumption will be very high.

Therefore, if the traditional sulfite sugar clarification process can be coupled with membrane separation technology, the pH value of the sugarcane juice should be adjusted to neutral and alkaline before the sugarcane juice enters the ceramic membrane, and then the sugarcane juice is subjected to low-intensity sulfur Smoke the sugarcane juice so that the sulfur fumigation strength of the sugarcane juice is 4-6mL, and then enter the ceramic membrane ultrafiltration to obtain the clarified sugarcane juice, and finally send the clarified sugarcane juice to evaporation concentration, boiling sugar crystallization, and then you can get white sugar with good quality . The sugarcane juice obtained by this method has a small amount of sulfur to protect the color, which can not only inhibit the generation of Maillard pigment, but also prevent the small molecule pigment from adhering to the surface of the sucrose crystal. The sugarcane clarified juice produced has low color value, high purity, With low turbidity, high-quality farmland white granulated sugar comparable to that of carbonic acid can be finally obtained.

Contents of the invention

The purpose of the present invention is to provide a sugar clarification production line, which solves the problem of the poor clarification effect of the traditional sulfite sugar clarification process, high sulfur content and low quality of the finished sugar, and the color of the finished sugar obtained by processing sugarcane juice with traditional membrane separation technology. High technical issues.

In order to achieve the above object, the present invention adopts the following technical solutions:

A sugar clarification production line includes a mixed juice tank, a horizontal screw centrifuge, a first heating device, a sulfur fumigation device, a second heating device, a multi-stage ceramic membrane ultrafiltration system and a plate and frame filter press connected in sequence.

A first buffer tank is connected between the decanter centrifuge and the first heating device, a second buffer tank is connected between the sulfur fumigation device and the second heating device, and the second heating device and the multi-stage ceramic membrane ultrafiltration system A third buffer box is connected between them.

The inlet of the mixed juice box is connected with the squeezing and extracting section of the sugarcane sugar factory and the lime milk tank, the outlet of the mixed juice box is connected with the inlet of the decanter centrifuge, the outlet of the decanter centrifuge is connected with the inlet of the first buffer tank, and the outlet of the first buffer tank It is connected with the inlet of the first heating device, the outlet of the first heating device is connected with the sugar juice inlet of the sulfur fumigation device, the sugar juice outlet of the sulfur fumigation device is connected with the inlet of the second buffer tank, the outlet of the second buffer tank is connected with the inlet of the second heating device, and the The outlet of the second heating device is connected to the inlet of the third buffer tank, the outlet of the third buffer tank is connected to the inlet of the multi-stage ceramic membrane ultrafiltration system, the permeate outlet of the multi-stage ceramic membrane ultrafiltration system is connected to the inlet of the sugarcane clarified juice storage tank, and the sugarcane clarification The outlet of the juice storage tank is connected to the evaporative concentration and sugar boiling crystallization section, the concentrated solution outlet of the multi-stage ceramic membrane ultrafiltration system is connected to the inlet of the plate and frame filter press, and the filtrate outlet of the plate and frame filter press is connected to the inlet of the first buffer tank.

The first heating device includes a first tube-and-tube heat exchanger, a second tube-and-tube heat exchanger, and a third tube-and-tube heat exchanger connected in series, and one of the heaters plays the role of washing and replacing in rotation.

The second heating device includes a fourth tube-and-tube heat exchanger, a fifth tube-and-tube heat exchanger, and a sixth tube-and-tube heat exchanger connected in series, and one of the heaters plays the role of washing and replacing in rotation.

The sulfur fumigation device includes a first vertical sulfur fumigation device and a second vertical sulfur fumigation device connected in parallel, wherein one sulfur fumigation device plays the role of washing and replacement in rotation.

The sulfur gas inlet of the sulfur fumigation device is connected with a sulfur dioxide gas supply source.

The multi-stage ceramic membrane ultrafiltration system is a five-stage parallel ceramic ultrafiltration membrane, and each stage of ceramic membrane is composed of two membrane modules, one of which plays the role of washing and replacement in rotation.

Compared with the prior art, the present invention has the beneficial effects:

(1) Only a small amount of lime and SO ₂ are added in the clarification process of sugarcane mixed juice. Because the added SO ₂ is less, the sulfur content in the finished sugar is very little, and the color value is low, the purity is high, and the ash content is low, thereby It ensures that the finished sugar can meet the needs of high-end customers. In addition, in the sugarcane juice clarification process, ceramic membrane ultrafiltration is used for clarification. Due to the small membrane resistance caused by scaling on the ceramic membrane, the membrane permeation flux of the ceramic membrane for filtering sugarcane juice is relatively large, and the flux decay rate of the ceramic membrane is slow. , can maintain a high membrane flux filtration, thereby prolonging the membrane cleaning cycle and reducing the frequency of membrane cleaning.

(2) A multi-stage ceramic membrane ultrafiltration system composed of five-stage parallel ceramic ultrafiltration membranes is adopted. Each stage is composed of two membrane modules, and one stage acts as a replacement wheel for washing, ensuring the long-term performance of the ceramic membrane ultrafiltration system. Time to run stably.

(3) A decanter centrifuge is used to coarsely filter sugarcane juice. Compared with traditional sugarcane juice coarse filtration equipment such as drum sieve, curved sieve and vibrating screen, the decanter centrifuge has compact structure, high separation efficiency and large production capacity. , Less auxiliary equipment and so on.

(4) Before the sugarcane juice enters the ceramic membrane ultrafiltration system for clarification, adjust the pH value of the sugarcane juice to 7.5-7.8, and then carry out low-intensity sulfur fumigation on the sugarcane juice, so that the sulfur fumigation intensity of the sugarcane juice is controlled at 4 Between ~6mL, it has the following advantages: a. The pH value of sugarcane juice after adding lime milk to adjust is slightly alkaline, after sulfur fumigation, heating, ultrafiltration and other processes, its pH value will drop to 7.0 ~ 7.2, and then Then the clarified sugarcane juice is sent to evaporation concentration and boiled sugar crystallization, thereby preventing the sugarcane juice from the technical problem of more sucrose conversion due to the low pH in the processing process; b. In the traditional sulfite sugar clarification process It is necessary to add more SO ₂ (sulfur fumigation intensity is 25-30mL) to react with milk of lime to generate more CaSO ₃ precipitates to absorb non-sugar impurities in sugarcane juice to achieve the purpose of clarifying sugarcane juice. Due to the addition of sulfur More often lead to more sulfur residues in the final finished sugar, thereby affecting the quality of the finished sugar, and the present invention uses ceramic ultrafiltration membranes to remove the absolute sulfur in sugarcane juice on the basis of the existing sulfite sugar clarification process. Most of the non-sugar impurities, and add a small amount of SO ₂ to the sugarcane juice, because the sugarcane juice has sulfur to protect the color, it can not only inhibit the formation of Maillard pigment, but also prevent the small molecule pigment from attaching to the surface of the sucrose crystal, and the produced Sugarcane clarified juice has low color value, high purity, and low turbidity, and finally high-quality farmland white sugar comparable to carbonation can be obtained.

(5) After the membrane concentrate is processed by a plate and frame filter press, it is then returned to the coarsely filtered sugarcane juice storage tank to avoid the problem of waste due to direct draining of the concentrate.

Description of drawings

Fig. 1 is the schematic diagram of the sugar clarification production line of the present invention.

In the picture: sugarcane sugar factory pressing and extracting section 1; lime milk tank 2; mixed juice tank 3; horizontal screw centrifuge 4; first buffer tank 5; first tube-and-tube heat exchanger 6; second tube-and-tube heat exchanger Heat exchanger 7; third tubular heat exchanger 8; first vertical sulfur fumigation device 9; second vertical sulfur fumigation device 10; second buffer tank 11; fourth tubular heat exchanger 12; Five-tube heat exchanger 13; sixth tube-type heat exchanger 14; third buffer tank 15; multi-stage ceramic membrane ultrafiltration system 16; sugarcane clarified juice storage tank 17; plate-and-frame filter press 18; evaporation and concentration 19. Sugar boiling crystallization section 19; sulfur dioxide gas supply source 20.

Detailed ways

The technical solution of the present invention will be further elaborated below through examples.

Example 1

A sugar clarification production line, including a mixed juice box 3, a decanter centrifuge 4, a first heating device, a sulfur fumigation device, a second heating device, a multi-stage ceramic membrane ultrafiltration system 16, and a plate and frame filter press connected in sequence Machine 18.

A first buffer tank 5 is connected between the decanter centrifuge 4 and the first heating device, a second buffer tank 11 is connected between the sulfur fumigation device and the second heating device, and the second heating device and the multi-stage ceramic membrane A third buffer tank 15 is connected between the ultrafiltration systems.

The inlet of the mixed juice box 3 is connected with the pressing and extracting section 1 of the sugarcane sugar factory and the lime milk tank 2, the outlet of the mixed juice box 3 is connected with the inlet of the decanter centrifuge 4, and the outlet of the decanter centrifuge 4 is connected with the inlet of the first buffer tank 5 Connection, the outlet of the first buffer tank 5 is connected with the inlet of the first heating device, the outlet of the first heating device is connected with the sugar juice inlet of the sulfur fumigation device, the sugar juice outlet of the sulfur fumigation device is connected with the inlet of the second buffer tank 11, and the second buffer tank 11 The outlet is connected to the inlet of the second heating device, the outlet of the second heating device is connected to the inlet of the third buffer tank 15, the outlet of the third buffer tank 15 is connected to the inlet of the multi-stage ceramic membrane ultrafiltration system 16, and the multi-stage ceramic membrane ultrafiltration system 16 is transparent The liquid outlet is connected to the inlet of the sugarcane clarified juice storage tank 17, the outlet of the sugarcane clarified juice storage tank 17 is connected to the evaporative concentration, sugar boiling and crystallization section 19, the outlet of the concentrated solution of the multi-stage ceramic membrane ultrafiltration system 16 is connected to the inlet of the plate and frame filter press 18 Connection, the filtrate outlet of the plate and frame filter press 18 is connected to the inlet of the first buffer tank 5 .

The first heating device includes a first tube-and-tube heat exchanger 6 , a second tube-and-tube heat exchanger 7 and a third tube-and-tube heat exchanger 8 connected in series, and one of the heaters plays the role of washing and replacing in rotation.

The second heating device includes a fourth tubular heat exchanger 12 , a fifth tubular heat exchanger 13 and a sixth tubular heat exchanger 14 connected in series, and one of the heaters plays the role of washing and replacement in rotation.

The sulfur fumigation device includes a first vertical sulfur fumigation device 9 and a second vertical sulfur fumigation device 10 connected in parallel, wherein one sulfur fumigation device plays the role of washing and replacement in rotation.

The sulfur gas inlet of the sulfur fumigation device is connected with a sulfur dioxide gas supply source 20 .

The multi-stage ceramic membrane ultrafiltration system 16 is a five-stage ceramic ultrafiltration membrane in parallel, and each stage of ceramic membrane is composed of two membrane modules, one of which plays the role of washing and replacement in rotation.

Example 2

This embodiment is an example of actual production using the sugar clarification production line described in Example 1, and the specific steps are as follows:

(1) Liming: adding milk of lime with a concentration of 8.0 ° Be to the mixed juice of the sugarcane sugar factory, adjusting the pH value of the sugarcane juice to 7.6, preventing the sucrose in the sugarcane juice from converting under acidic conditions, resulting in the loss of sucrose, and obtaining limed cane juice;

(2) Coarse filtration: Utilize a decanter centrifuge with an aperture of 50.0 μm to filter the ash-added sugarcane juice to obtain the coarsely filtered sugarcane juice;

(3) Heating for the first time: heating the coarsely filtered sugarcane juice to 55°C with a shell and tube heat exchanger, which is beneficial to the absorption of SO by the sugarcane juice in the next step of sulfur fumigation process, and obtaining the sugarcane juice heated for the _first time;

(4) Sulfur fumigation: Utilize the sulfur fumigation device to carry out sulfur fumigation to the sugarcane juice heated for the first time to obtain sulfur fumigation sugarcane juice with a sulfur fumigation intensity of 4 mL;

(5) Second heating: heat the sulfur-smoked sugarcane juice to 80-90°C with a tube-and-tube heat exchanger to obtain the second heating sugarcane juice;

(6) ceramic membrane ultrafiltration clarification: the second heating sugarcane juice is carried out ultrafiltration clarification with a multi-stage ceramic membrane ultrafiltration system with a membrane pore size of 0.05 μm, to obtain clarified sugarcane juice and membrane concentrate;

(7) Evaporation and crystallization: After the clarified sugarcane juice is concentrated by evaporation and crystallized by boiling sugar, white granulated sugar can be obtained;

(8) Recovery of the membrane concentrate: filter the membrane concentrate with a plate and frame filter press, mix the filtrate with the coarsely filtered sugarcane juice, and repeat steps (3) to (7).

The sulfur fumigation device described in step (4) is two parallel vertical sulfur fumigation devices, one of which plays the role of washing and replacement in rotation.

The operating parameters of the ceramic membrane in step (6) are as follows: the transmembrane pressure difference is 0.1-0.3Mpa, the membrane surface flow velocity is 4-5m/s, and the filtration temperature is 80-90°C.

The multi-stage ceramic membrane ultrafiltration system described in step (6) is a five-stage ceramic ultrafiltration membrane connected in parallel, and each stage of ceramic membrane is composed of two membrane modules, one of which plays a role of washing and replacement in rotation.

The plate and frame filter press described in step (8) needs diatomite filter aid.

The physical and chemical indexes of the white granulated sugar processed in embodiment 2 are shown in the following table:

^* The National Standard of the People's Republic of China GB317-2006

Example 3

This embodiment is another example of actual production using the sugar clarification production line described in Embodiment 1, and the specific operation steps are as follows:

(1) Liming: adding milk of lime with a concentration of 8.5 ° Be to the mixed juice of the sugarcane sugar factory, adjusting the pH value of the sugarcane juice to 7.5, preventing the sucrose in the sugarcane juice from converting under acidic conditions, resulting in the loss of sucrose, and obtaining limed cane juice;

(2) Coarse filtration: Utilize a decanter centrifuge with an aperture of 150.0 μm to filter the ash-added sugarcane juice to obtain the coarsely filtered sugarcane juice;

(3) Heating for the first time: heating the coarsely filtered sugarcane juice to 65°C with a shell and tube heat exchanger, which is beneficial to the absorption of SO by the sugarcane juice in the next step of sulfur fumigation process, and obtaining the sugarcane juice heated for the _first time;

(4) Sulfur fumigation: Utilize the sulfur fumigation device to carry out sulfur fumigation to the sugarcane juice heated for the first time, to obtain sulfur fumigation sugarcane juice with a sulfur fumigation intensity of 6 mL;

(5) Second heating: heat the sulfur-smoked sugarcane juice to 80-90°C with a tube-and-tube heat exchanger to obtain the second heating sugarcane juice;

(6) ceramic membrane ultrafiltration clarification: the second heating sugarcane juice is carried out ultrafiltration clarification with a multi-stage ceramic membrane ultrafiltration system with a membrane pore size of 0.10 μm, to obtain clarified sugarcane juice and membrane concentrate;

(7) Evaporation and crystallization: After the clarified sugarcane juice is concentrated by evaporation and crystallized by boiling sugar, white granulated sugar can be obtained;

(8) Recovery of the membrane concentrate: filter the membrane concentrate with a plate and frame filter press, mix the filtrate with the coarsely filtered sugarcane juice, and repeat steps (3) to (7).

The sulfur fumigation device described in step (4) is two parallel vertical sulfur fumigation devices, one of which plays the role of washing and replacement in rotation.

The operating parameters of the ceramic membrane in step (6) are: transmembrane pressure difference of 0.1-0.3 MPa, membrane surface flow velocity of 4-5 m/s, and filtration temperature of 80-90°C.

The multi-stage ceramic membrane ultrafiltration system described in step (6) is a five-stage ceramic ultrafiltration membrane connected in parallel, and each stage of ceramic membrane is composed of two membrane modules, one of which plays a role of washing and replacement in rotation.

The plate and frame filter press described in step (8) needs diatomite filter aid.

The physical and chemical indexes of the white granulated sugar processed in embodiment 3 are shown in the following table:

^* The National Standard of the People's Republic of China GB317-2006.

Claims (6)

1. A clarification production line for sugar refining, characterized in that it comprises a mixed juice box, a horizontal screw centrifuge, a first heating device, a sulfur fumigation device, a second heating device, a multistage ceramic membrane ultrafiltration system and a plate frame filter press; A first buffer tank is connected between the decanter centrifuge and the first heating device, a second buffer tank is connected between the sulfur fumigation device and the second heating device, and the second heating device and the multi-stage ceramic membrane ultrafiltration system A third buffer box is connected between them; The inlet of the mixed juice box is connected with the squeezing and extracting section of the sugarcane sugar factory and the lime milk tank, the outlet of the mixed juice box is connected with the inlet of the decanter centrifuge, the outlet of the decanter centrifuge is connected with the inlet of the first buffer tank, and the outlet of the first buffer tank It is connected with the inlet of the first heating device, the outlet of the first heating device is connected with the sugar juice inlet of the sulfur fumigation device, the sugar juice outlet of the sulfur fumigation device is connected with the inlet of the second buffer tank, the outlet of the second buffer tank is connected with the inlet of the second heating device, and the The outlet of the second heating device is connected to the inlet of the third buffer tank, the outlet of the third buffer tank is connected to the inlet of the multi-stage ceramic membrane ultrafiltration system, the permeate outlet of the multi-stage ceramic membrane ultrafiltration system is connected to the inlet of the sugarcane clarified juice storage tank, and the sugarcane clarification The outlet of the juice storage tank is connected to the evaporative concentration and sugar boiling crystallization section, the concentrated solution outlet of the multi-stage ceramic membrane ultrafiltration system is connected to the inlet of the plate and frame filter press, and the filtrate outlet of the plate and frame filter press is connected to the inlet of the first buffer tank. 2. The sugar clarification production line according to claim 1, wherein the first heating device comprises a first tubular heat exchanger, a second tubular heat exchanger and a third tubular heat exchanger connected in series. Heaters, one of which plays the role of washing and replacing. 3. The sugar clarification production line according to claim 1, wherein the second heating device comprises a fourth tubular heat exchanger, a fifth tubular heat exchanger and a sixth tubular heat exchanger connected in series. Heaters, one of which plays the role of washing and replacing. 4. The clarification production line of sugar refining as claimed in claim 1, wherein said sulfur fumigation device comprises a first vertical sulfur fumigation device and a second vertical sulfur fumigation device connected in parallel, wherein one sulfur fumigation device plays a round wash Replacement role. 5. The sugar clarification production line according to claim 1, wherein the sulfur gas inlet of the sulfur fumigation device is connected to a sulfur dioxide gas supply source. 6. The clarification production line for sugar refining as claimed in claim 1, wherein the multi-stage ceramic membrane ultrafiltration system is a five-stage parallel ceramic ultrafiltration membrane, and each stage of ceramic membrane is composed of two membrane modules, of which there is a It plays the role of wheel washing replacement.