Page 1. Grain cooling for minimizing losses and preserving quality. GRANIFRIGOR TM grain cooling What is Grain Cooling Conservation?

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1 1 NATIONAL SUMMIT ON FOOD GRAINS STORAGE IN INDIA Grain cooling for minimizing losses and preserving quality What is Grain Cooling Conservation? A riskless long term storage of grain without quality losses, achieved by cooling with conditioned ambient air below 13 C in approx. 3 weeks after harvest or procurement, independent of the weather conditions! by Dr. Claus M. Braunbeck Manager Asia FrigorTec GmbH, Germany Principle of grain cooler GRANIFRIGOR TM with sun protection Page 1

2 2 GRANIFRIGOR TM with air ducts connection Why grain cooling? Minimization of respiratory losses (dry substance) Protection against damages and development of insects Protection against microbes and mould fungi Extended storage time / Flexibility Reduction of drying costs Grains live, breathe, and give off heat! Grain respiration - the totals formula for the chemical process: C 12 H 22 O O 2 12 CO H 2 O + 1,567 x 10-3 kwh Carbohydrates + Oxygen Carbon dioxide + Water + Heat Mass balance for the respiration of 1 kg carbohydrates: 1,000g + 1,122.81g 1,543.86g g +.48 MJ Carbohydrates + Oxygen Carbon dioxide + Water + Heat This process depends on the product moisture level and temperature. Source: Heat build-up, modification based on Jouin Page 2

3 3 Calculation of dry substance losses by respiration Data Formula Grain loss [t] = Result Grain Type Paddy Moisture Content of Grain 14.5 [%] Grain temperature 30 [ C] Grain price 300 [EUR/t] Storage period 4 [months] Storage quantity 10,000 [t] heat generation [MJ/t, day] x storage period [day] x storage quantity [t] 15,000 [MJ/t] x (1 moisture content of grain) x 0.8* Paddy loss [t] Monetary loss [EUR] grain stored at 30 C ,325 grain stored at 25 C ,3 grain cooled to 10 C minimal (< 1) * correction of husk Insect pest development Growth of selected organisms Source: Lacey J. Grain temperature ( C) Storage period (days) max. 3 weeks 12 Grain moisture content (%) Target values for grain! During the storage period, regular inspections and, if necessary, protective measures, are required. Page 3

4 4 Slowly reheating of cold stored grain because of: Only point contact of seeds Low convection of air between the seeds Low heat conductivity of grain substance Low water content of grain Energy consumption of grain cooling depending on: relative humidity and temperature of ambient air product temperature and moisture content adjusted cold-air temperature Practical values: 3-5 kwh per ton (moderate climate) 8-10 kwh per ton (tropical climate) Combination drying - cooling Combination drying - cooling Page 4

5 5 Advantages of grain conservation by cooling (Part 1) Risk-free long-term storage without quality loss Conservation of harvest freshness for outstanding taste Minimizing respiration losses Protection from insects and their damage Avoiding expensive and risky chemical treatment like fumigation Protection of organic grain Protection from fungi and their mycotoxin Reduction from drying costs and energy consumption No yellow discoloration because of over drying and low storage quality Higher head rice recovery because of less fissures and cracks Advantages of grain conservation by cooling (Part 2) Higher milling performance and efficiency Faster parboiling with brighter whiteness of rice Simplification of storage management Independent operation of weather conditions No aeration damage by rewetting of grain No breakage nor grinding loses by circulation Conservation of germination quality for fast grow and high yield Increase of revenue and improving of market position Short amortization period Thank you for your attention! Contact: Page 5