The study scientific farming "RICE DRYING TO MECHANICAL Minimise" ThistrainingmanualbroughttoyoubyCARDprojectVIE026/025 – NongLamUniversityHCMC – TheUniversityofQueensland,Australia MECHANICALRICEDRYINGTO MINIMISE 1. Higher rice quality and longer storage period: less cracked grain, higher head rice yield. COMPARISONOF  EFFICIENCY  Ismechanicalrice dryingbetterthansun drying?! TRAININGMANUAL    2. More active, less weather dependence (alternative sun and rain , flood ) Cost: Mechanical rice drying cost is not too high as compared to sun drying: • Mechanical drying: 40-50 VND/kg; • Sun drying: 30-40 VND/kg (sunny day); 120-130 VND/kg (rainy day). Sun drying (high labor cost, large area required for drying, weather dependen t, …) 3. Less grain losses due to attacks of pests, rodents, poultry… Quality: Mechanical dried rice is better in terms of: • Increase in head rice recovery • Decrease in grain losses. Mechanical drying (less labor required, more active…) …it is sunn y It’dbettertoapply mechanicalricedrying evenif Economic efficiency: higher benefit than sun drying (66-76 VND/kg after expenditure deduction). 4. Cost-saving and issues regarding labor force, small space required for drying. Contactinformation:Dr.TruongVinh,ProjectLeader,HeadDepartmentofChemicalEngineering,NongLamUniversityHCMC,Tel:0 8 ‐7242527/724503 0 ThistrainingmanualbroughttoyoubyCARDprojectVIE026/025 – NongLamUniversityHCMC – TheUniversityofQueensland,Aus t ralia Contactinformation:Dr.TruongVinh, ojectLeader,HeadDepartmentofChemicalEngineering,NongLamUn versityHCMC,Tel:0 VARI ARE Pr i 8 ‐7242527/724503 0   NORMAL and REVERSIBLE AIRFLOW FLAT BED DRYERS  OPERATIONTECHNIQUE  1. Paddy loading Load a uniform moisture content paddy to dryer (set-back feeding, don’t trample upon paddy)Æ level the surface of paddy load. Thickness of paddy for flat bed drying, airflow upward: 30-35cm; reverse downward: 60-70cm. 2. Furnace burning Husk furnace: Spread husk, set husk on fire until husk burned outÆ start the dryer. Coal furnace: Use fire-wood to set coal on fire Æ start the dryer. 3. Drying air checking: Drop a paper on the surface of paddy, and then speed dryer up gradually; + Drying-airless if a paper is still on the surface of paddy + A paper flies upon the surface of paddy 2-3 cm indicating drying air sufficiency Drying air should be widespread over the surface of paddy mass. 4. Dry Use tempe 42 o C; Higher rice qu Lower drying ing temperature monitoring OUSTYPESOFDRYERS CURRENTLYUSING thermometer to monitor drying rature: : food rice 45 o C; seed rice: drying temperature results in lower ality; drying temperature leads to longer timeÆ energy cost. 5.Grai - Grai drying: interva - Air r drying fan, c metal benea airflow n mixing or air reversal n mixing: applied for normal flat-bed switch off the fan, mix paddy in 2h l. eversal: Applied for reversible airflow : Stop the heat supply, switch off the over paddy by the plastic sheet or lid, open both drying air outlet th and air distribution tube upper for going through. 6. Red After paddy over-h ucing drying temperature a paddy reversal, continue to dry at 38 o C to prevent the bottom layer eating. 7. Air Stop h contin before blowing eating when paddy is dried uniformly, ue air blowing 45 mins for cooling finishing up the drying batch. Caution drying t rice rec increas For exa recover recover : Drying paddy “properly” uses appropriate emperature and air volume so that high head overy is obtained. Drying paddy “improperly” es the level of losses due to grain breakage. mple, drying 100 kg paddy: Drying “properly”: s 62 kg “rice 10%”; Drying “improperly”: s 50-54 k g “rice 10%” Nong Lam University, HCM city – The University of Queensland, Australia- CARD Project 026/VIE05 Contact Address: CARD 026/VIE05 Office ment - Nong Lam University, HCM city, Tel.: 08-7242527/ 7245030, Email: cnhh@hcmuaf.edu.vn Chemical Engineering Depart RICE HARVESTING METHODS: MINIMISING LOSSES There are 4 common harvesting methods: 1. Manual cutting Æ field drying, manual collecting Æ machine, threshing Advantages: Low threshing energy due to short rice stem, independent of soil condition and the degree of rice lodging, high cleanness of rice Disadvantagess: High grain losses, low capacity, large number of labourers – poor rice quality if raining before threshing 2. Cutting by reaper Æ field drying, manual collecting Æ machine, threshing Advantages: The machine is not heavy, high capacity (1-6 ha/day); it can work in the soft soil field - high cleanness of rice, low investment, high mobility Disadvantagess: Long rice stem leading to high threshing energy, lager grain losses, large number of labourers for collection, hard to harvest lodged rice, poor rice quality if raining before threshing 3. Cutting by reaper Æ combine collecting and threshing Advantages: The reaper is not heavy, high capacity (1-6 ha/day); it can work in the soft soil field, high cleanness of rice, high mobility Disadvantagess: Large investment; long rice stem leading to high threshing energy, difficult to harvest lodged rice, poor rice quality if field drying is applied before collecting. 4. Harvesting by combine harvester Advantages: High capacity- save time and labourers, good rice quality, limited rice cracking. Disadvantagess: Low mobility when using caterpillar- depending on soil firmness - difficult to harvest lodged rice – hard to maintain the harvester, high investment CONSIDERED ISSUES WHEN INVESTING AND USING THE COMBINED HARVESTER: - Selection of appropriate harvesting method and harvester type for high capacity should base on soil conditions and cultivated season. - Movability of combine harvester on farm depends on its weight and the firmness of field soil base. Moving by caterpillar has lower mobility than others. - The machine has many complex components and parts. Thus, care, maintenance and operation of the machine should be carried out properly. SOME COMBINED HARVESTERS CURRENTLY USED IN THE MEKONG RIVER DELTA Company Operation width(m) Recommended field Vinappro Nhựt Thành Chín Nghĩa Út máy cày 1,2 1,3 1,5 1,9 Narrow, soft soil Narrow, soft soil Moderate field, dry soil Moderate to large field Nong Lam University HCM city, Viet Nam – Queensland University, Australia - CARD 026/VIE05 Project For more information, contact Dr. Truong Vinh, Head Chemical Engineering Department - Nong Lam University, HCM city Tel.: 08-7242527/ 7245030, Email: cnhh@hcmuaf.edu.vn OPTIMUM HARVESTING TIME Famers agreed that late harvesting caused reduction in head rice yield Variety Season Growing time Wet 88 90 92 94 96 98 OM1490 Dry 88 90 92 94 98 104 Wet 88 90 92 94 96 98 OM2718 Dry 88 90 92 94 96 98 Wet 86 88 90 92 94 96 OM2517 Dry 82 84 86 88 90 92 Wet 86 88 90 92 94 96 OM4498 Dry 87 89 91 93 95 97 Jasmine Wet 94 96 98 100 102 104 AG 24 Wet 86 88 90 92 94 96 IR50404 Wet 88 90 92 94 96 98 Late harvesting Early harvesting The date of physiological maturity, good time for harvesting What are rice losses? Losses from harvesting ? Losses from drying, storage ? Losses from milling ? Harvesting time experiments More broken rice (Late harvesting) More head rice (correct harvesting) 80 – 85% of rice is ri p e Reasons for late harvesting: lack of labour, harvesting is concentrated in a short time… Solution methods: - Mechanical harvesting - To plant varieties with different maturities in the same location 1. Harvesting after maturation date increased cracking fraction and reduced head rice yield 2. A late harvesting of 4-6 days reduced 7- 28% head rice yield equivalent to a loss of 600.000 – 2.100.000 VND/ha Encouraged harvesting time (shade red color) This training manual brought to you by CARD Project 026/VIE-05 – Nong Lam University HCMC – The University of Queensland, Australia Trainin g manual RICE MILLING TECHNOLOGY Project Co-ordinators: Australia- Bhesh Bhandari and Shu Fukai, The University of Queensland, Australia Vietnam: Truong Vinh, Head Department of Chemical Engineering, Nong Lam University HCMC; Tel: 08-7242527/7245030 Selecting appropriate rice milling system and technology in production scale Milling quality enhanced Size of millin g p lant versus millin g q ualit y Milling plant Head rice Cracked rice Broken rice Bran Husk Small 48% 19% 3% 10% 21% Medium 52% 14% 3% 10% 21% Lar g e 55% 13% 3% 10% 20% Larger production scale, less cracked grains. Brown rice milling quality in small scale plant Huskers Head rice Cracked rice Broken rice Bran Husk Disc 47% 19% 3% 10% 21% Rubber roll 51% 17% 3% 9% 20% Combined 49% 18% 3% 9% 21% Coffee type 43% 23% 2% 10% 22% Huskers Head rice Cracked rice Broken rice Bran Husk Disc 50% 16% 4% 9% 21% Rubber roll 54% 13% 3% 10% 20% Combined 53% 14% 3% 10% 20% Brown rice milling quality in medium scale plant Corresponding milling capacities for large, medium & small scales are above 4 tons/h, 1-4 tons/h, and below1 ton/h, respectively. Combined type is the combination of disc and rubber roll huskers. Husker Head rice Cracked rice Broke n rice Bran Husk Combined 55% 13% 3% 9% 20% Using combination of 2 huskers for brown rice milling Disc husker is applied firstly to mill p add y Rubber roll husker is applied secondly for unhusked rice Enhance milling capacity, reduce maintenance cost, low cracked g rains. Milling system for white rice consists of 3 units of cone shape mill. Each unit removes bran layers consecutively. Rice milling and polishing system, capacity 5 tons/h. Brown rice milling quality in large scale plant Stone m ill Coffee mill Coffee husker: capacity 0.2 ton/h, high cracked grains, low head rice yield, mobile. Disc husker: high cracked grains, low maintenance cost, capable of milling high moisture content rice. Cone shape mill: milling thoroughly, high cracked grains. Rubber r Cone shape mill o ll h usk e r Rubber roll husker: low cracked grains, low capacity, high maintainance cost. . The study scientific farming "RICE DRYING TO MECHANICAL Minimise" Thistrainingmanualbrought to youbyCARDprojectVIE026/025 – NongLamUniversityHCMC – The UniversityofQueensland,Australia . to sun drying: • Mechanical drying: 40-50 VND/kg; • Sun drying: 30-40 VND/kg (sunny day); 120-130 VND/kg (rainy day). Sun drying (high labor cost, large area required for drying, weather. start the dryer. Coal furnace: Use fire-wood to set coal on fire Æ start the dryer. 3. Drying air checking: Drop a paper on the surface of paddy, and then speed dryer up gradually; + Drying- airless