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Effects - Sean Currans – AG 21 August 2013

SOLAR FRUIT DRYING

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Effects - Sean Currans – AG 21 August 2013

Value Adding

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Effects - Sean Currans – AG 21 August 2013

Aftabi Raisins

Grower price Aftabi

$0.50 to $2.00/kg

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Effects - Sean Currans – AG 21 August 2013

Kishmish Raisins

Grower price = $2.00 to $5.00 / kg

Premium 25mm Shundukhani kishmish

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Kishmish Khana Tradition

Large 30 meter long Kishmish Khana• Estimate $12,000 cost to build• 13,500kg fresh Shundukhani yield 3,300kg kishmish

• 13,500 x $0.30/kg = $4,050 cost of grapes• 3,300 x $2.00/kg = $6,600 gross• 3,300 x $5.00/kg = $16,500 gross• Gross kishmish revenue - cost of grapes = added value

• $6,600 - $4,050 = $2,550 added value• $16,500 - $4,050 = $12,450 added value

• 30 days to dry grapes and traditionally one batch per season

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Improved Direct Solar Drying

• More sanitary• Faster drying• More productive

• “Direct” Solar• Maybe Kishmish if use p.metabisulfite?

• “Batch” process

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Critical Kishmish Parameters

What makes Kishmish raisins?

• Shundukhani grapes• Shade

– minimal Ultraviolet light

• Lower temperatures– Probably no higher than 38 Celsius

Should experiment with potassium carbonate and potassium metabisulfite

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Raisin Production

• Drying grapes– Heat– Air flow– Relative Humidity– Time

• Drying can be faster, if:– Higher temperatures are maintained 24/7– More airflow– Grapes are spread in thin layers– Some grape treatments are used

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Kishmish Khana / Kishmish Konex™?

Is Kishmish Khana necessary ?

Perhaps containers will be better?

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Effects - Sean Currans – AG 21 August 2013

Break & Questions

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Effects - Sean Currans – AG 21 August 2013

Technical Raisin Questions

Kishmish Raisin Quality1. If constant 38 Celsius temperature, will quality be

same?

2. If raisins are dried faster with more airflow, will quality be same?

3. If grapes are pre-treated to speed drying, will quality be the same?

• Potassium carbonate• Blanch hot water• Other

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Effects - Sean Currans – AG 21 August 2013

Conventional Dryer with Gas Heat

‘McKenzie’ Dryer• 1860kg fresh grape• 465kg Kishmish• $930-$2325 per load Kishmish• Guessing 48 hr per load at 38 Celsius

Estimate Cost to run• Electric fan = $1.00/hr• Gas heat= $5.00/hr

$6/hr x 48 hr = $288

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Effects - Sean Currans – AG 21 August 2013

Indirect Solar Drying

Containers• Inexpensive• Protects fruit from sun• Easy sanitation• Easy to modify to create indirect solar dryer

65 Celsius

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Effects - Sean Currans – AG 21 August 2013

Solar Container Dryer Estimates

Rough estimate:• 9,525kg fresh Shundukhani grapes = 2,116kg kishmish

• With high airflow only perhaps dry in 8 days

• With high airflow and solar collector with heat storage, perhaps dry in 4 days.

• 2,100 kg Kishmish x $2/kg = $4,200 in 8 days?

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Experiment Proposed

• Thin layer grapes• 80mm tray spacing• High speed fan airflow• container with solar collector or without

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Effects - Sean Currans – AG 21 August 2013

Small Scale Experiment Proposed

Small test box could make from wood• Thin layer grapes on mesh trays• 80mm tray spacing• High speed fan airflow• Keep grapes in dark• ensure fresh ambient airflow

How many hours to dry grapes into Kishmish raisins?

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Effects - Sean Currans – AG 21 August 2013

Break & Questions

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Effects - Sean Currans – AG 21 August 2013

Solar Dryer - only ambient heat

Insulated ducting

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Effects - Sean Currans – AG 21 August 2013

What is a Solar Collector?

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Effects - Sean Currans – AG 21 August 2013

Solar dryer -with collector only

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Effects - Sean Currans – AG 21 August 2013

What is Heat Storage?

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Effects - Sean Currans – AG 21 August 2013

Solar Collector and Heat Storage

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Effects - Sean Currans – AG 21 August 2013

Solar Dryer Workflow

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UNCLASSIFIED//FOUO

Effects - Sean Currans – AG 21 August 2013

Solar Container Dryer Estimates

Rough estimate:• 9,525kg fresh Shundukhani grapes = 2,116kg kishmish

• With high airflow only perhaps dry in 8 days

• With high airflow and solar collector with heat storage, perhaps dry in 4 days.

• 2,100 kg Kishmish x $2/kg = $4,200 in 8 days?

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Effects - Sean Currans – AG 21 August 2013

Questions

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Effects - Sean Currans – AG 21 August 2013

Summary

1. Anybody want to learn more?

2. Shall we build a small test dryer box?

3. Shall we build a pilot Kishmish Konex™?