CRYOGENIC GRINDING
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OBJECTiVES
•INTRODUCTION
•PROBLEMS IN CONVENTIONAL GRINDING
•WORKING
•ADVANTAGES OF CRYO GRINDING
•EXPERIMENTAL STUDIES
•APPLICATION
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CRYOGENICS
The term “ Cryogenics” originated from the Greek word which
means creation or production by means of cold. Cryogenics is
the study of very low temperatures or the production of the
same.. Liquid nitrogen is the most commonly used element in
cryogenics and is legally purchasable around the world.
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APPLICATIONS OF CRYOGENICS
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In Gas Industry
As the source of gas
As Rocket propellant
In Biology
In Food Industry
In Electronics
In Medicines
In Grinding
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GRINDING
The process is carried out with a grinding wheel made up of grits for
removing materials from work piece surface.
Grinding can be classified into two types
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Grinding for material removal
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Grinding for powdering
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PROBLEMs IN CONVENTIONAL
GRINDING PROCESS
• High heat generation
• Introduction of tensile residual stress
• Less tool life
• Clogging and Gumming of the mill
• Oxidation
• Loss of Etheric oil in Spice grinding
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Now….elimination of all these problems are required……..
But……….
HOW..???
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Here comes the necessity of
CRYOGENIC
GRINDING
…..also known as Freeze Grinding
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CRYOGENIC GRINDInG
Cryogenic grinding involves cooling a material below its
embrittlement temperature with cryogenic fluid. Typically
Liquid Nitrogen or in certain applications, liquid Carbon
Dioxide is used.
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This process has several benefits
• Ability to process soft or elastic material
• Increased productivity
• Low Power Consumption
• Smaller size particle
• Minimal loss of volatile component
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WORKING
06/09/2010
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ADVANTAGES OF CRYOGRINDING
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Increased throughput & power saving
Finer particle size
More uniform particle distribution
Lower grinding cost
No heat generation
Provides an inert atmosphere
Reduced grinding force
Provide clean and pollution free environment
Prevent oxidation
Possibility of fine grinding of difficult spices
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RESULTS OF EXPERIMENTAL STUDIES
1. Volatile oil content & flavor component
Example : pepper
SL No.
Components
Cryoground(%)
Conventional
ground(%)
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Moisture
13.00
11.00
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Volatile oil
2.61
1.15
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Flavour compounds
(relative concentration)
Alpha pinene
limonene
1.40
8.30
0.29
1.18
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2. Throughput of the mill
Current required
=6A
Working temperature
=50°C
Throughput of conventional grinding
=22kg/hr
Throughput of cryogenic grinding
=50kg/hr
i.e. throughput for cryogenic grinding is 2.25 times more
than conventional grinding
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APPLICATION OF CRYO-GRINDING
• recycling of composite materials
• Thermoplastics
• Thermo sets
• Adhesives & waxes
• Explosives
• Spices
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Hence we can conclude …..
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THank you …
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QUESTIONS ? ?
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