CN103757143A - Syrup clarification method - Google Patents

Abstract

The invention relates to a method for clarifying sugar juice, which belongs to the technical field of sugar juice clarification in the sugar industry. The sugar juice clarification method is the sugar juice air flotation clarification and membrane separation coupling technology to clean the sugar juice, including three main processes of sugar juice air flotation clarification pretreatment, sugar juice air flotation clarification, and sugar juice membrane separation system; The sugar juice is pre-treated by air flotation and clarification, that is, the sugar juice is filtered through a filter, lime, phosphoric acid is added to adjust the pH value, and the first-level heat treatment is carried out. The clear sugar juice obtained by air flotation clarification is firstly processed by the sugar juice filtration system, and then enters the high-efficiency sugar juice membrane separation system for clarification, and finally obtains clear sugar juice whose clarification quality is not lower than that of the traditional sugar making process, thus completing The clarification process of sugar juice. The technical process of the present invention mainly adopts air flotation clarification and membrane separation coupling technology, the method is simple and advanced, the residence time of sugar juice is short, the loss of sucrose is small, the clarification is stable and controllable, and the clarification efficiency is high. It is an effective measure for sustainable development and has a good application prospect.

Description

A kind of sugar juice clarification method

technical field

The invention belongs to a method for clarifying sugar juice by using air flotation clarification and membrane separation coupling technology. The sugar juice described in the sugar juice includes sugarcane initial press juice, sugarcane mixed juice, sugarcane exudate juice, beet exudate juice, and neutralized juice , intermediate sugar juice and concentrated syrup in the process of filtering juice and evaporation, used for clarification of sugar juice in sugar cane and beet sugar production, the residence time of sugar juice is short, the loss of sucrose is small, the clarification is stable and controllable, the clarification efficiency is high, and the sugar can be improved. The cleaning effect of the juice and the quality of the product are effective measures for the sugar factory to realize clean production and implement sustainable development, and it has a good application prospect.

Background technique

There are classic carbonation and sulfurous acid clarification processes for the mixed juice in the sugar factory. Due to the large discharge of filter sludge, low organic matter content and calcium carbonate content of more than 80%, the carbonation method has no agricultural value. At present, carbonation at home and abroad The filter mud of French sugar factories is basically treated by wet discharge or dry discharge, which has caused serious pollution to the environment. Due to the serious problem of filter sludge pollution in the carbonic acid sugar production process, many sugar factories choose the sulfurous acid clarification process. The traditional sulfurous acid There are problems such as high sulfur fumigation intensity, low sugar juice clarification efficiency, long residence time of sugar juice in the settler, and easy bottom reversal in the operation and control of the settling tank. These problems need to be solved urgently.

Research on the traditional sulfurous acid clarification process has been going on, such as the use of semi-carbon and semi-sub-method sugarcane juice air flotation clarification and low-temperature phosphorus floating sugar juice clarification, which can remove sugar in sugarcane juice. Cane bran, starch, sucrose fat, sucrose wax, plant pigments, proteins and colloids and other non-sugar components are beneficial to the post-processing effect. Chinese Patent (Application No.) 201310082816.9 discloses a sugarcane juice clarification method, which uses part of the mixed juice to make foam, float and clear the separation combined with the rapid sedimentation method of sugar juice to clarify the sugar juice. Floating separation, secondary heating, sulfur fuming neutralization, neutralizing juice heating, and rapid sedimentation steps to obtain clear juice can stabilize the pH value of clear juice, avoid "bottom inversion" and "sucrose conversion" in sedimentation tanks, save production costs and reduce environmental pollution. Pollution, improve product quality; Chinese patent (application number: 201110360967.7) discloses a method for parallel production of nutritional sugar, flavor cane juice and feed materials with multi-stage membranes. The method uses multi-stage membrane filtration for the production of nutritional sugars.

The more advanced sugar solution clarification methods in foreign countries include ion exchange method and membrane separation method. Ion exchange method is widely used in foreign sugar refineries. Due to the complexity and high management requirements, domestic sugar refineries have not been well applied and promoted. Due to the many problems of membrane materials and membrane attenuation, the membrane separation method has not yet been demonstrated and applied in large-scale industrial white sugar production.

Therefore, there is an urgent need to develop a new process for cleaning high-efficiency sugar juice that can meet the requirements of my country's cultivated land white granulated sugar to solve these problems.

Contents of the invention

The invention provides a method for cleaning sugar juice by air flotation clarification and membrane separation coupling technology, which can solve technical defects such as waste pollution, low cleaning efficiency, low membrane flux, and short membrane service life in the traditional sugar production process. , and can obtain higher quality clear sugar juice.

The present invention is achieved through the following technical solutions.

A sugar juice clarification method, comprising three main processes of sugar juice air flotation clarification pretreatment, sugar juice air flotation clarification, and sugar juice membrane separation system, characterized in that: firstly, the sugar juice is subjected to air flotation clarification pretreatment, that is, the sugar juice Carry out filter screen filtration, add lime, phosphoric acid to adjust the pH value and primary heat treatment. After the treatment, the sugar juice enters the sugar juice air flotation clarification system for treatment, that is, after the pretreatment, the sugar juice is added again to adjust the pH value of lime or phosphoric acid Juice or part of the sugar juice is bubbled, flocculants and clarifiers are added to remove the non-sugar network in the sugar juice, and the floating clear sugar juice obtained by the air flotation clarification treatment system is first processed by the sugar juice filtration system, and then enters the high-efficiency sugar juice Clarify in the membrane separation system, and finally obtain the clear sugar juice whose clarification quality is not lower than that of the traditional sugar making process, thus completing the clarification process of the sugar juice.

The sugar juice includes sugarcane initial press juice, sugarcane mixed juice, sugarcane exudate juice, sugar beet exudate juice, neutralized juice, filtered juice, intermediate sugar juice in the evaporation process and concentrated syrup.

The sugar juice is subjected to air flotation and clarification pretreatment. The filter mesh of the filter system is 100-800 mesh, adding lime and phosphoric acid to control the pH value in the range of 6.0-11.0, and the phosphoric acid value is _P2O per kilogram of sugar juice The number of ₅ mg is calculated in the range of 200-450 mg, and the temperature after one heating is in the range of 50-65 °C.

In the sugar juice air flotation clarification system, the process index control of adding lime again is that the pH value is in the range of 7.0 to 8.5, and the total value of phosphoric acid in the sugar juice is in the range of 400 to 500 mg calculated as ₅ mg of _P2O per kilogram of sugar juice. The flocculant used is a polymer flocculant for sugar, the amount of flocculant is 2-10ppm to the amount of sugar juice, and the amount of clarifying agent for sugar is 0.1%-10% to the amount of sugar juice.

The filtration precision of the sugar juice filtration system after air flotation clarification is in the range of 5-40 microns, the filtration membrane precision of the sugar juice membrane separation system is in the range of molecular weight 2000 to 2 microns in membrane pore size, and the filter screen filtration system and membrane separation system are suitable for temperature In the range of 45 to 110 degrees, the Brix of the processed sugar juice is in the range of 10 to 78oBx.

The quality of the clear sugar juice obtained by the sugar juice clarification method is not lower than that obtained by the traditional sugar clarification method.

The present invention has strong adaptability, and when the non-sugar components in the sugar juice of different regions, different varieties and different raw materials are quite different, the high-efficiency clarification can be completed by simply adjusting the main operating parameters in the operation process, which is effective. Facilitate the realization of automatic control. Compared with the existing sugar juice clarification process, the invention is beneficial to reduce production energy consumption and improve product quality.

Compared with prior art solutions, the present invention has the following characteristics and progress:

1. Use low-temperature air flotation to clarify sugar juice, adjust the pH value twice, improve the efficiency of air flotation clarification, and meet the pH value requirements of the traditional evaporation process, without having to go through the sulfur fumigation process for clarification again;

2. Using filter screen filtration and membrane separation method to clean sugar juice can replace the traditional sugar clarification production process, which can improve sugar recovery, product quality and product food safety, improve membrane separation flux, and prolong membrane service life.

Attached picture

Fig. 1 is a process flow diagram of the present invention.

Detailed ways

The specific embodiments of the present invention will be described in further detail below in conjunction with the accompanying drawings, but this does not constitute any limitation to the present invention.

A sugar juice clarification method, comprising three main processes of sugar juice air flotation clarification pretreatment, sugar juice air flotation clarification, and sugar juice membrane separation system, characterized in that: firstly, the sugar juice is subjected to air flotation clarification pretreatment, that is, the sugar juice Carry out filter screen filtration, add lime, phosphoric acid to adjust the pH value and primary heat treatment. After the treatment, the sugar juice enters the sugar juice air flotation clarification system for treatment, that is, after the pretreatment, the sugar juice is added again to adjust the pH value of the sugar juice, all the sugar juice or Part of the sugar juice is foamed, flocculants and clarifiers are added to remove the non-sugar network in the sugar juice, and the floating clear sugar juice obtained by the air flotation clarification treatment system is first processed by the sugar juice filtration system, and then enters the high-efficiency sugar juice membrane separation Clarify in the system, and finally get the clear sugar juice whose clarification quality is not lower than the traditional sugar making process, thus completing the clarification process of the sugar juice.

The sugar juice is sugarcane mixed juice, the Brix is 16.5 ± 0.5oBx, the sugar juice is subjected to air flotation clarification pretreatment, the mesh number of the filter screen filter system is 200 mesh, adding lime and phosphoric acid to control the pH value at 8.0 ± 0.2, After the first heating, the temperature is 58±0.5°C; adding lime or phosphoric acid to the sugar juice air flotation clarification system to control the process index is that the pH value is 7.5±0.1, and the total value of phosphoric acid is calculated as ₅ mg of P ₂ O per kg of sugar juice. 400±10mg, the amount of flocculant to the amount of sugar juice is 3ppm, the amount of sugar clarifier to the amount of sugar juice is 2±0.2%; the filtration accuracy of the filter filter system is 10 microns, and the filtration accuracy of the sugar juice membrane separation system is 0.2 microns .

The sugar juice clarification process is as follows: the sugar juice is firstly pretreated, and the pretreated sugar juice is pumped to the sugar juice pH adjustment reaction box again, and then flows to the whole juice foaming box and clarifier and flocculation reaction box, and then passes through the sugar juice The air flotation clarification tank is used for clarification treatment, the scum is heated to about 85°C and washed into the mud tank, the floating sugar juice is filtered through a curved sieve (80 mesh) and then flows into the floating clear sugar juice tank, and the floating clear sugar juice passes through the sugar juice delivery pump Sent to the filter filter system for automatic filtration, the obtained filtered clear sugar juice is sent to the membrane separation system by a booster pump for precise cleaning treatment, the permeate is the clean sugar juice, which is sent to the evaporation system after secondary heating; The collected liquid flows back to the mixed juice box and then enters the whole juice bubble making box for another air flotation treatment.

The sugar factory mixed juice was measured, the turbidity was 29886.00 MAU, the color value was 3157.82 IU, and the simple purity was 81.15; after the traditional sulfurous acid treatment, the turbidity was 103.56 MAU, the color value was 1808.34 IU, the simple purity After being treated by air flotation-membrane separation method, the turbidity was 83.27 MAU, the color value was 1773.96 IU, and the simple purity was 82.42, indicating the quality of clear sugar juice clarified by air flotation clarification and membrane separation coupling technology: clear juice and The purity difference of the mixed juice is close to that of the traditional method, and the turbidity and color value indicators of the sugar juice are good, which fully meets the quality of the traditional clarification process.

Claims (6)

1. A sugar juice clarification method, comprising three main processes of sugar juice air flotation clarification pretreatment, sugar juice air flotation clarification, and sugar juice membrane separation system, characterized in that: firstly, the sugar juice is carried out air flotation clarification pretreatment, that is, The sugar juice is filtered through a filter, added lime, phosphoric acid to adjust the pH value and first-level heat treatment. After the treatment, the sugar juice enters the sugar juice air flotation clarification system for treatment, that is, after the pretreatment, the sugar juice is adjusted by adding lime or phosphoric acid again. All or part of the sugar juice is foamed, flocculants and clarifiers are added to remove the non-sugar network in the sugar juice, and the floating clear sugar juice obtained by the air flotation clarification treatment system is first processed by the sugar juice filtration system, and then enters the high-efficiency The clarification in the sugar juice membrane separation system finally obtains the clear sugar juice whose clarification quality is not lower than that of the traditional sugar making process, thus completing the clarification process of the sugar juice. 2. A kind of sugar juice clarification method according to claim 1, is characterized in that: described sugar juice comprises sugarcane press juice, sugarcane mixed juice, sugarcane exudate juice, beet exudate juice, neutralization juice, filter Juice, intermediate juice from the evaporation process and concentrated syrup. 3. A method for clarification of sugar juice according to claim 1, characterized in that: said sugar juice is subjected to air flotation clarification pretreatment filter screen filter system with a mesh number of 100-800 mesh, adding lime and phosphoric acid The pH value is controlled in the range of 6.0-11.0, the phosphoric acid value is calculated in the range of 200-450 mg based on ₅ mg of P ₂ O per kg of sugar juice, and the temperature after one heating is in the range of 50-65°C. 4. A method for clarification of sugar juice according to claim 1, characterized in that: in the sugar juice air flotation clarification system, the technological index control of adding lime again is that the pH value is in the range of 7.0 to 8.5, and the total phosphoric acid in the sugar juice is The value is in the range of 400-500 mg based on ₅ mg of P ₂ O per kg of sugar juice. The flocculant used is a polymer flocculant for sugar. The amount of flocculant is 2-10 ppm for sugar juice. The amount of sugar juice is 0.1% to 10%. 5. A method for clarification of sugar juice according to claim 1, characterized in that: the filtration accuracy of the juice filtration system after air flotation clarification is in the range of 5 to 40 microns, and the filtration membrane accuracy of the juice membrane separation system In the range of molecular weight 2000 to membrane pore size of 2 microns, the filter screen filtration system and membrane separation system are suitable for temperatures in the range of 45 to 110 degrees, and the Brix of sugar juice is in the range of 10 to 78oBx. 6. A method for clarifying sugar juice according to claim 1, characterized in that: the quality of clear sugar juice obtained by the method for clarifying sugar juice is not lower than that obtained by traditional sugar refining methods.

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