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Cooling to the point

Natural Paddy & Rice conservation by grain cooling

Ralph E. Kolb

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GRAIN COOLING

A riskless long term storage of paddy or rice without quality losses,

achieved by cooling with conditioned ambient air in a range of 13 to 18°C

in approx. 3 weeks after harvest, independent of the weather conditions!

to save the quality of Paddy & Rice !

What do we understand by Paddy & Rice cooling conservation ?

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GRAIN COOLINGCooling -process

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GRAIN COOLINGAir distribution (in silo cells with conical outlet)

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GRAIN COOLINGGRANIFRIGORTM at honey comb silos

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GRAIN COOLINGWarehouse cooling

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GRAIN COOLING

• Minimization of respiratory losses (dry substance)• Protection against damages and development of insects

• Protection against microbes and fungi

• No discoloring (yellowcoloring) of the rice

Why grain cooling ?

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GRAIN COOLINGLosses of dry substance

Grain respiration - the totals formula for the chemical process:

C12H22O11 + 12 O2 → 12 CO2 + 11 H2O + 1,567 x 10-3 kWhCarbohydrates + Oxygen → Carbon dioxide + Water + Heat

This process depends on the product moisture content and temperature.

Mass balance for the respiration of 1 kg carbohydrates:

1,000g + 1,122.81g → 1,543.86g + 578.95g + 16.48 MJCarbohydrates + Oxygen → Carbon dioxide + Water + Heat

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GRAIN COOLINGLosses of dry-substance (acc. to Jouin)

14,5%

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GRAIN COOLINGCalculation of dry substance losses by respiration

DataGrain Type PaddyMoisture Content of Grain 14.5 [%]Grain temperature 30 [°C]Grain price 300 [EUR/t]Storage period 4 [months]Storage quantity 10,000 [t]

Formula

Grain loss [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*

ResultPaddy loss [t] Monetary loss [EUR]

grain stored at 30°C 87.8 26,325grain stored at 25°C 43.9 13,163grain cooled to 10°C minimal (< 1) ---------

* correction of husk

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GRAIN COOLING

Lesser grain borer

Triboliumcastaneum

Insects

maize weevilSitophilus zeamais

granary weevil

Sitophilus granarius

rice weevil

Sitophilus oryzae

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GRAIN COOLING

Grain weevil population growth

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GRAIN COOLINGInsect infestation

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GRAIN COOLINGDevelopment of damaging insects

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GRAIN COOLINGDevelopment of various mould fungi

Fusarium culmorum 400 x

Aspergillus glaucus

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GRAIN COOLING

Humid air which is coming in contact with dry grain will lead to wetting

of the grain.

Risks of ventilation with ambient air

Never introduce moist air into dry grain !

Never introduce warm air into cooler grain !

Specially high wetting of the grain will take place when in addition the

air temperature is higher then the temperature of the grain.

Paddy and rice are hygroscopic !

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GRAIN COOLINGSorption isotherm of paddy

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GRAIN COOLING

• Reduction of the drying costs

• The product is treated more carefully – without resulting in crack

Combination drying - cooling

...during the cooling process grain looses moisture

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GRAIN COOLINGCombination drying - cooling

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GRAIN COOLINGCombination drying - cooling

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GRAIN COOLINGGRANIFRIGORTM with air ducts connection

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GRAIN COOLING

GRANIFRIGORTM

at twin operation

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GRAIN COOLING

• Risk-free long-term storage without quality loss

• Minimizing respiration losses

• Protection from insects and their damage

• Avoiding expensive and chemical treatment like fumigation

• Protection from fungi and their mycotoxins

• Reduction from drying costs

• No yellow discoloration because of over drying

• Higher head rice recovery because of less fissures and cracks

Advantages of grain conservation by cooling

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GRAIN COOLING

Thank you for your attention !

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GRAIN COOLING

Rice/ Paddy - Cooling to the point

GRANIFRIGOR™Natural Conservation