SUGAR SUGAR TECHNOLOGY, CAKES TOPIC CENTRIFUGAL DRYING, PACKING AND PRESERVING

DEPARTMENT OF MECHANICAL AND TECHNOLOGY SUGAR SUGAR TECHNOLOGY, CAKES TOPIC: CENTRIFUGAL - DRYING, PACKING AND PRESERVING Instructors: Associate Professor Ph.D Nguyen Van Toan Class: Food Technology 52B Group: 03 Member : Hoang Thi Hong Luu Duong Vu Quoc Khanh Vo Thi Yen Linh Tran Thi Kieu Huong Tran Thi Ly Hue TABLE OF CONTENTS PART 1: CENTRIFUGAL 1.1 OVERVIEW .4 1.1.1 Purpose of sugar centrifuge 1.1.2 Centrifugal principle 1.2 TREATING YOUNG SUGAR BEFORE CENTRIFUGATION .8 1.2.1 The dilution of young sugar 1.2.2 Sugar heating .8 1.2.3 Devices containing young sugar before centrifugation .8 1.3 FACIAL SEPARATION CENTRIFUGE 10 1.3.1 Startup .10 Sinh viên: Nguyễn Thị Hương Lớp: Sử 1.3.2 K28C Charge .11 1.3.3 Molasses 11 1.3.4 Washing the sugar .12 1.3.5 Stop and discharge the road 14 1.4 FACTORS AFFECTING THE CENTRIFUGAL PROCESS 14 Huế, tháng 11/2007 1.4.1 Massecnite quality .14 1.4.2 Worker's operation techniques 15 1.5 CLASSIFICATION OF CENTRIFUGAL PROCESS 15 1.5.1 Single Centrifuge 15 1.5.2 Dual centrifuge 15 1.5.3 C line double bile (C line re-sieve) 16 1.6 LOW SUGAR TREATMENT AFTER CENTRIFUGATION 16 1.6.1 Road Lake 16 1.6.2 Recollection of cane sugar 17 1.6.3 Cane sugar screw conveyor .17 1.7 EQUIPMENT .18 1.7.1 Flat bottom Weston discontinuous centrifuge 18 1.7.2 Inertial continuous centrifuge 19 PART DRYING SUGAR 20 2.1 OVERVIEW 20 2.1.1 Purpose of sugar drying process .20 2.1.2 The principle of sugar drying 21 2.1.3 Methods of drying crystalline sugar 21 2.2 SOME EQUIPMENT IN THE SUGAR DRYING PROCESS .22 2.2.1 Equipment for conveying granulated sugar from centrifuge to sugar dryer 22 2.1.3 Rotary drum dryer 24 2.1.4 Fluidized bed dryers 25 PART 3: SUGAR PRESERVATION 27 3.1 Possible phenomena when storing sugar .27 LIST OF PICTURE Figure 1 Diagram of the centrifugal system with intermittent line A .5 Figure Diagram of the continuous centrifugation system for road B Figure Diagram of continuous centrifugation system for line C (centrifugation twice for line C) Figure Screw-type road distribution trough .10 Figure Sugar heating equipment 10 Figure Cane sugar screw conveyor 18 Figure Flat bottom Weston discontinuous centrifuge 19 Figure Inertial continuous centrifuge 20Y Figure Diagram of drying system and finished product 21 PART 1: CENTRIFUGAL 1.1 OVERVIEW Figure 1 Diagram of the centrifugal system with intermittent line A Assistive devices; Distribution trough; Intermittent centrifuge; Container for raw honey A; Container containing diluted bile A; Sand sugar A Bile pump B Bile pump B Figure Diagram of the continuous centrifugation system for road B Horizontal assistant; Distribution trough; Continuous centrifuge equipment; Container for bile B Bile pump C Bile pump C2 Resuscitation pump Molasses pump Figure Diagram of continuous centrifugation system for line C (centrifugation twice for line C) Horizontal assist device; Distribution trough; Continuous centrifuge equipment; C2 bile container; Return sugar barrel; Container for molasses 1.1.1 Purpose of sugar centrifuge Sugar centrifugation is the process of separating sugar crystals from molasses by centrifugal force in rotating vats at high speed After centrifugation, for young sugar A, you will get sugar A, brown molasses (raw honey A) and white bile (diluted honey A) The dissociation process relies on the centrifugal force field to separate the two solid-liquid phases into separate components 1.1.2 Centrifugal principle Young sugar is a suspension mixture (consisting of sugar crystals and molasses) In principle, to separate the solid phase from the liquid phase, the methods of centrifugation, gravity sedimentation, and centrifugal filtration are used However, young sugar has a large solid phase ratio and high viscosity, so to separate the sugar crystals from the molasses, people use centrifugal filtration and are based on the principle of centrifugal force 1.1.2.1 Centrifugal force - When an object rotates about an axis, a centripetal force is generated on the surface of the object towards the center of the axis of rotation According to Newton's 3rd law, the reaction of the centripetal force will have the same direction, same magnitude but opposite direction and that reaction is called centrifugal force So centrifugal force is the reaction of the centripetal force obtained when an object is rotated about an axis When the centrifuge rotates to make the granulated sugar (solid) in the young sugar separate from the molasses (liquid body), centrifugal force is used The rotating centrifuge plate generates centrifugal force, causing the honey to splash out through the side mesh of the machine, while the fine grained sand that does not pass through the mesh stays behind Bile in the young sugar is separated under the action of centrifugal force - To increase the centrifugal force, we can increase the diameter of the turntable or the number of revolutions and increase the rotation speed to make the centrifugal force increase faster than the diameter However, in practice, it is necessary to check the quality of materials to increase the speed and not exceed the maximum speed allowed 1.1.2.2 Dissociation value The effects of different centrifuges are compared by calculating the ratio between gravity and the centrifugal force that can be exerted on the centrifuge mass The relationship between centrifugal force and gravity is expressed by the dissociation value The dissociation value is the ratio of centrifugal force to weight, which is also the ratio of centrifugal acceleration to gravity This value represents the principal characteristic of the centrifuge f = F/G When designing a centrifuge, it is calculated to have the largest centrifugation value In the case of wanting to increase speed, it is necessary to reduce the size of the wheel reasonably to ensure the stability of the turntable 1.1.2.3 Centrifugal pressure When the centrifuge rotates, the sugar fed into the rotating plate is subjected to centrifugal force and pressed against the wall of the plate, the honey through the sugar crystal layer exits the floor hole on the plate wall and flows out Due to the pressure of centrifugal force, the sugar layer is pressed close to the mesh wall 1.2 TREATING YOUNG SUGAR BEFORE CENTRIFUGATION 1.2.1 The dilution of young sugar The high concentration of molasses, combined with the high stickiness of the molasses, makes the transport and distribution of young molasses more difficult To overcome it, it is possible to dilute the young sugar by adding hot water to the outlet of the aid tank to ensure an even distribution of water The amount of water to dilute is about 2% of the volume of young sugar 1.2.2 Sugar heating While diluting the young sugar it is inevitable that some crystals will be dissolved Heating is another combined or alternative means of reducing the viscosity of the raw sugar, thereby reducing the re-dissolving of the unresolved sugar According to studies, the viscosity of molasses decreases by 50% or the ability to break down bile increases by 50% when the temperature is increased by Heating can be done in the vat or by means of a coiled tube in a gully or rapid heating devices 1.2.3 Devices containing young sugar before centrifugation 1.2.3.1 Road distribution troughs The young sugar after semen is discharged into the distribution trough to stir well and distribute to the centrifuges The young sugar dispenser is almost like the small aid box placed above the centrifuges, also in the centrifuge array, must have a volume corresponding to the volume of young sugar enough to handle in 15 or 30 minutes The trough is in the form of a U-shaped or closed cylindrical horizontal cylinder, inside with a screw-type stirrer with a speed of < - rpm To prevent sugar crystals from settling to the bottom of the trough, a small stirrer with rake is installed at the bottom with a speed of rpm The trough is tilted towards the centrifuge and has a drain hole for each centrifuge Figure Screw-type road distribution trough In actual production, another type of trough is also U-barrel type but has a square hollow shaft with paddle-type stirrer suitable for feeding the granules to each centrifuge For road C, the distribution trough is usually a two-shell device or has a heating element with hot water to raise the temperature of the young road to reduce viscosity Or there is also a closed cylindrical horizontal distribution trough with a propeller-type stirrer, without a heating system, so this type is often accompanied by a device to heat the path before entering the centrifuge 1.2.3.2 Resistive road heating device Figure Sugar heating equipment Raw road distribution trough; Electric heating; Continuous centrifugation; Line load screw Heating the slope with a resistor has many advantages: - Simple - Easy temperature check - The length of the road is short -> Thus, reducing the risk of crystals being re-dissolved and fully adapted to continuous centrifuges The optimal heating limit in the aid box or in the distribution trough is about 50 - 55, but with the small line resistance heating device, it saves very little time at high temperature, so it can be easily raised to 57 flow rate of molasses In some cases, hot air is also put in a closed barrel to prevent sugar from cooling and speed up the flow of molasses 1.4.2 Worker's operation techniques The worker has full knowledge, mastering the technical basis of molasses separation operation: massecnite quality indicators, having the judgment the degree of separation and humidity of the refined sugar, knowing how to maximize the ability of the centrifuge, the centrifugal process will be highly effective in terms of sugar quality, reduce losses, save energy, electricity and water costs 1.5 CLASSIFICATION OF CENTRIFUGAL PROCESS 1.5.1 Single Centrifuge The centrifugal process is once sequenced according to the stages of bile sorting cycle Start, recharge, declassify, wash the road, stop the machine and discharge the sugar 1.5.2 Dual centrifuge Centrifuge twice In the first centrifugation without steam washing, also known as pre-centrifugation The bile removed is bile The sugar after separating the molasses is discharged into the sugar tank placed under the preliminary centrifuges Here, we create young sugar by mixing with a density higher in purity than its female bile or mixing with tea bile or hot water to the appropriate concentration for the centrifuge process Take this mixture of lake roads to the second bile, called a complete centrifuge, this time it is possible to wash water or wash steam The bile obtained is diluted bile The dual centrifuge method gives good quality sugar and bile is very well divided but it requires two centrifuges instead of one This bile-defecation process is often called re-sieve and is usually done for young C sugar 1.5.3 C line double bile (C line re-sieve) Purpose: + Increases the ability to recover roads and ensures the safety of erratic treatment of the end line for reuse + Remove a large amount of starch in sugar i.e increase the quality of sugar A, sugar B The C path through the preliminary centrifuge, the C sand road is discharged into the lake barrel here is recycled into magma The substance used for the road is bile B B bile is taken in the container and diluted 70°Bx and heated to 70°C Magma is pumped onto the distribution trough of the finished centrifuge Redistributed C sugar falls in the sugar lake barrel mixed with magma C The rich C bile from the finishing centrifuges is used to cook C, not cook B 1.6 LOW SUGAR TREATMENT AFTER CENTRIFUGATION 1.6.1 Road Lake The concept of sugar lake: using raw materials such as bile or hot water mixed with sand sugar obtained after centrifuging into a mixture of young sugar (magma) with the required concentration used to sift back to obtain higher quality sand sugar or to make varieties of cooking higher-grade young sugars In factories producing white sand sugar, cooking 3-system sugar, sand B sugar is lakeed into magma (diluted sugar) as the same as cooking young sugar A: Sugar B from the centrifuge is conveyed by screw to the sugar slurry device, sprinkled with sugar and given an appropriate amount of tea molasses or clean water, dilute B sugar into a lake with a concentration of 86-91% pumped onto the A-sugar-like container stored The concentration of diluted sugar should not be too high or too low, if too high, it is difficult to pump the lake road, if too low will dissolve part of the sugar at a serious level, affecting the production rate 1.6.2 Recollection of cane sugar The concept Cane sugar recovery: use hot water in combination with saturated steam if necessary to completely dissolve the sand sugar into a sugar solution with an appropriate concentration into a higher-grade raw material for cooking young sugar Cane sugar recovery is done when you want to train raw sugar in the white sand sugar factory to make the most of equipment, steam, electricity and water Normally, the C sand line passed through resuscitation device into syrup with a concentration equivalent to or higher than the concentration of tea density, preliminary filtration through the grid to remove impuritiestreated with SO2 for a second time to reduce color, along with molasses cooked with young sugar A Technology requirements:must completely dissolve the sand sugar into syrup with the appropriate concentration or it will interfere in the cooking of young A sugar 1.6.3 Cane sugar screw conveyor Load screws are used for low-level road transfer, round particles with high stickiness It is common to use the transport of sand B, sand road C to the equipment of road lakes and road regression Figure Cane sugar screw conveyor The type of screw conveyor consists of a U-shaped trough, in the trough is installed a chicken intestine spiral shaft, the two ends of the shaft are supported The trough body is relatively long so there is a mid-support pillow This type often abrasives road particles, so it is often used to transport low-level roads to road lake equipment or road regression 1.7 EQUIPMENT 1.7.1 Flat bottom Weston discontinuous centrifuge - This type of centrifuge is commonly used for sand road A and sand road B at a speed of 960 rpm or a highway centrifuge for road C at a speed of 1,450 1,850 rpm Figure Flat bottom Weston discontinuous centrifuge Mesh basket, Rotary, Support pillow, Cone, Ledge, Rotary barrel, Engine, Coupling, Engine stop brake The machine consists of a 6th rotating crankshaft attached to the 2th axis, the shaft together with the barrel Thanks to the 3-axis support pillow is freely compared to the barrel The bottom of the machine is covered with the tip of the 4th cone located on the 5th ledge When discharging the top of the cone is raised by hand The barrel rotates in a fixed shell The bile separates through the grid as the centrifuge flows into the middle of the mesh and the barrel case, and then flows into the container Normally, on centrifuges lined with copper mesh panels, the outer plate has a hole size of × mm, the inner plate has a hole size of 0.5 × mm On the lock to the shaft bearing with a rubber layer of cushioning allows the shaft to move slightly around the vertical position This is the advantage of centrifuges, because if the shaft is hard in the bearing when new material is inserted, especially in the case of uneven raw materials, the machine is islanded, vibrating the floor, the shaft is strongly bending The centrifuge rotates thanks to the engine via coupling Stop with brake In addition, on the machine there is a steam and water drainage system for washing the road 1.7.2 Inertial continuous centrifuge Figure Inertial continuous centrifuge The working principle of the centrifuge is constantly inertial type: continuous centrifuges are often placed on the ground The young path leads in through a fixed tube to the bottom of the rotating barrel Thanks to the young road centrifuge force splashed around the barrel wall, and horizontally the barrel will be moved upwards Bile splashes through the hole of the barrel wall, while the line is splashed out above the rotating barrel PART DRYING SUGAR 2.1 OVERVIEW Figure Diagram of drying system and finished product Centrifugal zone; Sugar dryer; Sieve; Packing area; Silo; Special sugar production zone; Transport vehicle; Warehouse 2.1.1 Purpose of sugar drying process After centrifugation, if washed with hot water, the initial moisture is 1-2% and the temperature is about 60°C; In the case of steam washing, the initial humidity is 0,7 – 1,0% and the temperature is about 80°C With such humidity and temperature it is not possible to bag and store To avoid the sugar from clumping and metamorphosing, and at the same time to make the color of the finished sugar shiny Therefore, it is necessary to perform sugar drying to bring the temperature of the road down to the ambient temperature and humidity to only 0,05%, in order to ensure product quality and safety requirements in storage and circulation on the road market Thus, the purpose of sugar drying is to bring sugar to the appropriate humidity, increase the storage time, make the finished sugar shiny, not damaged or deformed during storage 2.1.2 The principle of sugar drying Use the heat released from the sugar itself after centrifugation, or use hot air to evaporate the water on the road surface The main factors affecting the drying rate of sugar: The grain size of the granules of the granulated sugar and the thickness of the layer The drying time will be shortened as the water evaporation surface area of the sugar increases If the crystals are too small, the sugar layer is too thick, the moisture inside is difficult to diffuse, and the drying speed is small The amount of water contained in the sugar is dried: if the granulated sugar after centrifugation has high moisture, the drying time will be prolonged Air temperature and humidity: the temperature of the air is high, the relative humidity is low, the hygroscopicity is strong, the drying speed is fast However, the hot air temperature should not be too high because it will affect the quality of sugar after drying Drying equipment: different equipment structure, drying speed is also different 2.1.3 Methods of drying crystalline sugar 2.1.3.1 Natural drying Normally, the temperature of granulated sugar after coming out of the centrifuge is higher than 80oC, we cool it down naturally to an appropriate temperature Taking advantage of its own heat to make the sugar dry However, this method takes a long time, it is difficult to control the finished product, and when the moisture content of the sugar after centrifugation is unstable, it will affect the drying efficiency 2.1.3.2 Hot air drying Dry the air first, reduce its relative humidity, and then put it in the dryer to contact the granules to absorb their moisture For this method, the drying time is relatively short and the amount of moisture in the finished sugar can be controlled 2.2 SOME EQUIPMENT IN THE SUGAR DRYING PROCESS 2.2.1 Equipment for conveying granulated sugar from centrifuge to sugar dryer 2.2.1.1 Vibrating conveyors transporting sugar (Vibrating floor) Figure 2 Vibrating floor Sieve surface; Connecting rod; Eccentric swing arm; Eccentric wheel; Sugar after centrifugation; Vibrating chute Vibrating sieves are placed directly under the centrifuges The main task of the vibrating screen is to transport the sugar released from the centrifuge to the bottom of the bucket At the same time, the sugar will cool and dry a small part, when transporting the sugar, it will not be crushed Usually used to transport sand road A The vibrating sieve is a deep flat-bottomed steel trough, the sides of which are fitted with a number of tweezers with dynamic joints and through a motor with an eccentric arm that causes the chute to vibrate and move back and forth 2.2.1.2 Bucket Load In the sugar manufacturing industry, using a lifting bucket is a type of equipment used to transport bulk materials (sand lines) from low to high in the vertical direction Figure Bucket load lifting Bucket load; Chain load; Bucket load body; Sprocket The two bucket ends have a sprocket, on the chain with equal distances, install the buckets Drive the lifting bucket by the motor through the reducer When in motion, the bucket transports the sand at the bottom by the chain moving up and through the top of the tower, the bucket reverses direction and pours the free-falling sand, making the road dry naturally This type of bucket takes up a very small area, but the granulated sugar is easily broken, causes dust, and is difficult to handle and classify If using a conveyor dryer for natural drying, not use a lifting bucket Just use the vibrating sieve to direct the route to the dryer 2.1.3 Rotary drum dryer At present, rotary drum dryer is being widely used in the sugar drying industry Figure Rotary drum dryer Air intake door; Caloriphe; Loading door; Gears; Rotary barrel; Belt; Exhaust gas pipes; Conveyor belt; Door outlet after drying; 10 Transmission mechanism; 11 Engine The machine consists of a cylindrical barrel that is placed horizontally and tilted slightly from the ground from to 6° Box rests on belt thanks to the 11 support roller system, which can be moved by the transmission system 10 through gear rotating at - rpm The entrance to the dryer is from inlet to the revolving drum After drying and cooling, the sugar is taken out through door and transferred to the bagging unit by conveyor The air is heated by caloriphe unit moving in the same direction as the sugar The air exits the dryer through the recovery cyclone The air temperature in and out of the dryer can be controlled automatically Working principle of the machine: after the wet material is put into the machine from the top of the rotating barrel, the machine starts to rotate and the inner blades the job of stirring the ingredients The material is stirred so that it will be fully exposed to the hot air and the moisture will be removed During such turning and drying, the material is moved from the top of the rotating barrel to the end of the barrel and reaches the required dryness, and finally the material is released through the unloader 2.1.4 Fluidized bed dryers The structure of this type of dryer is similar to a vibrating type dryer Figure Fluidized bed dryers Distribution segment; The boiling segment; The selection screening section; Air chamber; Current guide plate; Micro-perforated sheet; Adjustable brake plate; Top cap; Air; 10 Road; 11 Powdered sugar; 12 Finished sugar;13 Lump sugar Figure Schematic diagram of fluidized bed dryer Wet road; Hot air; Cold air; Air out; Dry sugar Fluidized bed drying is air-buffer drying, fast drying speed, large production capacity Cane sugar is placed on plates with microscopic holes, hot air is blown through small holes from below the plates to contact the top surface granulated sugar When the speed of the air flow reaches a certain value, the sugar layer will be smooth and together with the air form a uniform mixed state that rises to the conveyor belt like boiling water At this point, the sugar layer separates from the conveyor belt with the buffer air layer below Due to the constant vibration drying machine, the sugar layer will move in a floating state in the airflow, reducing the friction of the sand line with the extremely small hole sheet, avoiding damage to the angle of the crystal making the brightness of the crystal particle relatively good Typical boiling floor dryer: total length 13m, width 1m, inside the division in segments: distribution segment, boiling segment and selection segment The road is transferred to the distribution segment, during which the road movement is evenly distributed At the end of the distribution section place the wiper to control the thickness of the sugar layer before going into the boiling section The boiling segment is made up of the air chamber, the extremely small hole plate and the top cover In the lower layer there are two curved air current plates for even distribution of air, avoiding affecting the rate of drying Hot air enters the air chamber downstairs, passes through the current through the extremely small hole to enter the boiling section, then gets through the line and discharges out from the top cover The sand line from the boiling section comes out through the selection section and divides into types of sugar of different sizes Advantage: High drying effect, usually drying at the boiling point for only 12 seconds The total drying and sieve time is 70-80 seconds + Average yield per hour of 7.61 tons of sand sugar is equivalent to the yield of 1,500 tons of sugarcane per day Shortcoming: + Materials for making extremely small perforated panels + Relatively large drying bins PART 3: SUGAR PRESERVATION After drying and cooling, the sugar is transported by conveyor system to sorting sieve and then to the sugar-containing funnels Then, pack 50 kg on the bott machine Use a conveyor belt or hand truck to carry the road into the warehouse As well as packaged preserved foods, sugar bags are arranged in rows in the warehouse, which can be stacked 4-5 m high The warehouse is dry, the air humidity is relatively in the storage maintained from 55-65% Walls and warehouse floor lined with damp materials, with shelves lined with sugar 3.1 Possible phenomena when storing sugar 3.1.1 The sugar is damp - This phenomenon most often occurs and is most important during storage The air entering the warehouse will condense to the surface of the sugar crystal, making the sugar moist 3.1.2 Baking sugar - The main reason is that the sugar when drying has not cooled has been packed When the external temperature drops suddenly, the saturated layer of water around the sugar crystals can reach oversaturation giving birth to new crystals, which bind together gradually forming pieces of sugar It could also be for many other reasons 3.1.3 Metamorphes - Some microorganisms and molds turn sugar into butiric acid and lactic, xitric, acetic acid - After the sugar is moist, there are many yeasts that make the sugar metabolize These microorganisms are available in sugar cane, during the production may not be completely destroyed, when encountering low temperatures and the appropriate environment they return to action, or due to their penetration from the external environment To prevent this phenomenon, in the technology pay attention to cleaning sugar cane bran, not extend the time of cleaning and drying sugar crystals 3.1.4 Reduced sugar composition - It is also caused by sugar moisture Because when moistened sugar is susceptible to microorganisms and can cause the metabolism of sugar ... quality sand sugar or to make varieties of cooking higher-grade young sugars In factories producing white sand sugar, cooking 3-system sugar, sand B sugar is lakeed into magma (diluted sugar) as... cooking young sugar Cane sugar recovery is done when you want to train raw sugar in the white sand sugar factory to make the most of equipment, steam, electricity and water Normally, the C sand line... young sugar A: Sugar B from the centrifuge is conveyed by screw to the sugar slurry device, sprinkled with sugar and given an appropriate amount of tea molasses or clean water, dilute B sugar