The process flow of a sugar factory is: raw materials → juice extraction → clarification → evaporation → boiling sugar and crystallization → honey splitting → drying → sieving → packaging → storage \x0d\ 1.Juice Extraction \x0d\ China's sugar factories extract cane juice from sugarcane in three ways, namely, the pressing method, the oozing method and the milling and pressing method. These three methods are to destroy the sugar cane tissue cells containing sugar first. Sugar juice is then extracted by multiple pressing, multi-stage spraying or extrusion, respectively. Therefore, there is a difference between the equipment used in the various methods and their process conditions. \x0d\ Pressing method of extracting juice is a long history and relatively mature method. The main equipment used is the three-roll press. The cutting of cane before pressing is called the pretreatment of sugar cane. China's large and medium-sized sugar mills are usually equipped with two or three cane cutters, or cane cutters and rippers. The crushing of sugarcane with a ripper is currently used by only a few sugar mills in China, while it is more common in foreign countries. \x0d\ The exudation method is basically introduced from the sugar beet sugar production method or process. Practice has proved the superiority of sugarcane oozing method, not only lies in the low cost, low power consumption, safe operation, easy maintenance and management, and the sugar recovery rate is also very high. Therefore, the development of sugarcane juice extraction to the oozing method is inevitable. \x0d\ 2. Clarification\x0d\ The purpose is to improve the purity of the sugar juice by removing the non-sugar components, and to reduce its viscosity and color value, to provide high-quality raw molasses for the crystallization of boiled sugar. The traditional method of clarification used in sugar factories is simply to add lime as a clarifying agent to the sugar juice, so that some of the non-sugar precipitates and precipitates out, and after settling and filtration, the clear juice is produced, which is then sent to the evaporation station for evaporation and thickening to become syrup. \x0d\ There are three main processes involved in the clarification process, namely, heating of the cane juice, addition of clarifying agent and separation and precipitation. The main factors affecting clarification are the pH value of the cane juice, the heating temperature and the clarification time. The task of clarification can only be accomplished if these factors are well controlled so that as much sucrose as possible is retained while as much non-sugar is removed as possible. \x0d\ Sugar factory sugar production methods are generally named according to the clarification method, while the clarification method is named in accordance with the main clarifying agent used. At present, the world's sugar production method or clarification method, there are mainly lime method, sulfite method and carbonic acid method of three categories. In each category, according to the different processing steps and methods, and then divided into different methods. The more common ones are as follows: First, lime method. Which is divided into cold ash method, hot ash method, sub-ash method. Second, sulfite method. These include acidic sulfite method, alkaline sulfite method, neutral sulfite method, phosphoric acid sulfite method, intermediate juice sulfite method. Third, carbonic acid method. It can be divided into single carbonation, secondary carbonation, multiple carbonation, and intermediate juice carbonation. \x0d\ The three types of clarification methods mentioned above basically involve the addition of milk of lime and heat treatment, although the addition of lime and heating should be controlled in accordance with the requirements of the pH value. In addition, relatively new methods, such as ion exchange, are mostly used abroad for the production of refined sugar. Other methods such as electrodialysis, ultrafiltration and ion exclusion method are also under constant development. \x0d\ Lime method can only produce crude sugar with darker color, while white sugar for direct consumption can be produced by sulfite method. Although the white sugar produced by this method is inferior to that produced by the carbonic acid method in terms of whiteness and sugar yield, etc., the sulfite method is still widely used in large, medium and small cane sugar factories in China because it has the advantages of shorter process flow, less equipment and less amount of clarifying agent. In foreign countries, in the past decade or so, with the increase in consumption of refined sugar, many sugar mills using the sulfite method have been changed to the lime method, the production of crude sugar and then soluble refining. However, in the vast majority of developing countries, the sulfite method still occupies an important position. The use of lime and carbon dioxide as clarifiers to clarify cane juice is called the carbonic acid method. Carbonic acid method to remove the non-sugar than the sulfite method, the total recovery rate is also relatively high, and the finished product produced by the sugar purity is higher, lower color value, can be stored for a long time without discoloration. However, carbonic acid method also has some shortcomings, such as the process is more complex, need more mechanical equipment; also consume a lot of lime and carbon dioxide, so the production cost is higher. Especially in the sugar factory away from the limestone origin of the region, the promotion of carbonic acid method is subject to certain restrictions. \x0d\ 3. Evaporation\x0d\\ Before boiling sugar must be used to concentrate the sugar juice using multi-effect evaporation operation, sugar evaporation, which sucrose, reducing sugar and other non-sugar, in the temperature, pH and concentration and other conditions under the influence of the conditions, a series of chemical changes will occur. For example: sucrose conversion and coking, reducing sugar decomposition, scale build-up, etc. The laws of these chemical changes must be studied for better control. \x0d\ In general, the evaporation section must meet the requirements of the sugar production process and heat utilization and other aspects. First, to ensure syrup concentration. Second, reduce sugar loss. Third, slow down the rate of scale formation. Fourth, improve heat utilization and reduce heat loss. \x0d\ 4. Cooking and refining \x0d\ The crude syrup coming out of the final effect evaporation tank is then subjected to secondary sulfur fumigation, desaturation and filtration to achieve the purpose of bleaching and further clarification. After the second sulfur treatment of the syrup, known as clean syrup, generally still contains 35% - 45% of the water. Must be further concentrated and cooked to the precipitation of sucrose crystals, and make the crystal grain length to the size required. This process is called cooking sugar (or crystallization). The mixture of boiled sucrose crystals and sugar solution (mother liquor) is called sugar paste. Sugar paste is unloaded from the boiling sugar tank into the crystallization machine, after a gradual cooling process, to help the crystals continue to grow, so that the sucrose precipitation is more complete, which is called aided crystallization. The sugar paste after the crystal aid is sent to the centrifuge to separate the crystals from the mother liquor, which is called molasses separation. Sugar with hot air or other methods to remove water to meet the requirements of the moisture content, called drying. After drying sugar according to the size of the specifications with the sieve classification, called sieving. After sieving, the qualified sugar can be packaged as a finished product, and the separated molasses can be used as the raw material for the next level of sugar paste, and continue to be boiled and refined to the last level called waste molasses, i.e., by-products. \x0d\ A series of processes such as boiling, crystalizing, separating molasses, drying, sieving and packaging are the final section of sugar factory production, i.e. the boiling section. Good or bad work in this section has a great impact on product quality and sugar recovery. \x0d\ Boiling sugar and crystallization is the process of crystallization of sucrose. Auxiliary crystallization is the continuation of the crystallization process. Sugar paste in the end of cooking, especially the last section of the sugar paste, the crystal content has reached a certain level, the mother liquor concentration is high, low purity, so the sugar paste is very sticky, the crystallization speed is particularly slow, the ordinary sugar tank can not successfully complete the crystallization task, the need to move the sugar paste into the crystallization machine for crystallization, so that the grain as much as possible, to absorb the mother liquor of the sugar and grow, to complete the crystallization task. \x0d\crystallization principle: rely on the lowering of the temperature to maintain or increase the degree of supersaturation of the mother liquor, and enough time for the crystals to come into contact with the mother liquor. \x0d\ 5. Molasses Separation\x0d\ is the process of throwing out the molasses with the help of centrifugal force generated by the rapid rotation of the centrifuge, while the sucrose crystals remain in the sieve basket due to the obstruction of the sieve mesh. \x0d\ 6.drying\x0d\\ from the centrifuge out of the sugar, still contains 0.5% - 2.0% moisture, but also need to go through the drying and cooling, before packaging and storage, otherwise easy to moisture, caking deterioration, so that the sugar can not be stored for a long time. \x0d\ Granulated sugar contains moisture, will affect the quality of granulated sugar storage process changes. In the high concentration of sugar solution, microorganisms are unable to reproduce. Therefore, the ratio of non-sucrose fraction (non-spinosity) to water in the molasses liquid film remaining on the surface of granulated sugar grains will play a decisive role in the quality change of granulated sugar. That is, the high osmotic pressure of the molasses liquid film will be able to inhibit microbial growth. The ratio of water to non-sucrose sugar is often referred to as the "safety factor" (SF). \x0d\ At present, the separation of miscellaneous sugar in the sugar mill is mostly used in the steam washing method, so that from the centrifuge unloading sugar, the temperature of about 80 ℃, moisture content of about 0.5%, can be used to sugar from 80 ℃ down to room temperature when the heat itself will be released to the free moisture contained in the vaporization of sugar, so as to achieve the required moisture content of sugar standards, saving the air-heating equipment and air-blowing equipment. \x0d\ If the non-vaporized washing and separation of honey is used, the temperature of white granulated sugar is lower (50-60 ℃) and the moisture is higher (about 2%), so that it is necessary to dry the granulated sugar with hot air under the humid climatic conditions of the south, otherwise, it is difficult to ensure the quality of the product. The use of cold air and hot sugar temperature difference for natural cooling, so that the moisture of the wet sugar evaporation removed, until the sugar and the surrounding air temperature and humidity balance, this method is called natural drying. The air will be preheated, with hot air as a drying medium, so that the sugar trace moisture drying method, known as hot air drying. Natural drying method has been used in many sugar factories, the effect is better, the disadvantage is that the drying time is long, and in the centrifugal honey must be used when the steam wash to improve the temperature of sugar and reduce the moisture content of sugar, otherwise it will affect the drying efficiency. Hot air drying method, due to the short drying time, can shorten the length of the dryer, and the moisture of the finished sugar is also easy to control, therefore, is still used by some sugar factories. \x0d\ At present, the drying and cooling machine commonly used abroad are: rotary shutter type (also known as no coping rotary cylinder type) drying and cooling machine, vertical drying and cooling machine and boiling bed (also known as fluidized bed) drying and cooling machine three. \x0d\ 7. Screening \x0d\ from the dryer out of the sugar with a lot of lumps and sugar powder, etc., the grain size is not the same. In order to ensure product quality, so it is necessary to go through the screening and grading process, while the screening process can also make the sugar fully cooled, in order to facilitate packaging, storage. \x0d\ Sugar factory commonly used screening machine for the mechanical vibration screening machine, in the machine surface equipped with different specifications of the screen, screen installation method varies from plant to plant, generally in front of the smaller sieve holes, the back gradually increased. Sieving from too small granulated sugar and lumps of sugar cubes, factory commonly known as sugar head and sugar tail, to dissolve back, can not be used as a finished product factory. \x0d\ In foreign countries, the mechanical vibratory screening machine has been improved, the elastic rocker arm is no longer made of wooden slats, instead of spring coils, the latest change in the use of rubber columns, so that not only the structure is simple, easy to install and maintain, and the height of the equipment can also be reduced. In addition to mechanical vibration screening machine, foreign countries also use electromagnetic vibration screening machine and rotary screening machine. \x0d\ 8. Packaging \x0d\ After screening white sugar, unloaded into sugar bags by the sugar storage hopper, packaging. At present, China's sugar cane sugar factory production of white granulated sugar are used to plastic compilation bag packaging, and should be coarse, medium and fine grain white granulated sugar are packed separately, 50 kilograms per package. In large sugar factories have realized the packaging mechanization, automation, that is, in the storage of sugar under the bucket equipped with a lever-type automatic weighing, when the sugar bag full of 50 kilograms of sugar will automatically stop loading sugar, and then by the conveyor belt will be sent to the automatic weighing of the sugar packets to re-correct the weight, and then by the mechanical sewing machine for sewing, and then transported by the conveyor belt into the warehouse for storage. \x0d\ 9. Storage \x0d\ on the storage of sugar has a certain process requirements, otherwise it will be due to improper storage and the occurrence of deliquescence, caking, rancidity or discoloration and other accidents, affecting product quality. \x0d\ In the storage process of granulated sugar caking occurs mainly because of granulated sugar moisture content is too high (more than 1% above), which is often due to drying, packaging and warehouse temperature, humidity control is not normal and produce. In the drying process of sugar layer thickness control is not normal, so that the moisture content of sugar is not uniform, packaging into the warehouse will cause localized caking of sugar. Granulated sugar has not been sufficiently cooled for packaging and warehousing, warehousing and warehouse temperature difference is large, so that granulated sugar to absorb the moisture in the air and produce lumps. In addition, if the sugar package is stacked too high and under pressure, it will also cause caking. Souring is due to the presence of moisture and microbial action. White granulated sugar yellowing this is because the granulated sugar bleached with sulfite reduction, after a long time of storage due to the oxidation of the air and make the granulated sugar discoloration and yellowing. In order to prevent sugar deterioration in the storage process, the sugar warehouse address selection and sugar warehouse building should have certain requirements, and there should be a set of storage management system.