CRYOGENIC GRINDING 1 OBJECTi VES INTRODUCTION PROBLEMS IN
CRYOGENIC GRINDING 1
OBJECTi. VES • INTRODUCTION • PROBLEMS IN CONVENTIONAL GRINDING • WORKING • ADVANTAGES OF CRYO GRINDING • EXPERIMENTAL STUDIES • APPLICATION 2
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. 3
APPLICATIONS OF CRYOGENICS • In Gas Industry • As the source of gas • As Rocket propellant • In Biology • In Food Industry • In Electronics • In Medicines • In Grinding 4
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 • Grinding for material removal • Grinding for powdering 5
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 6
Now…. elimination of all these problems are required……. . But………. HOW. . ? ? ? 7
Here comes the necessity of CRYOGENIC GRINDING …. . also known as Freeze Grinding 8
CRYOGENIC GRINDIn. G 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. 9
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 10
WORKING 06/09/2010 11
ADVANTAGES OF CRYOGRINDING • 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 12
RESULTS OF EXPERIMENTAL STUDIES 1. Volatile oil content & flavor component Example : pepper SL No. Cryoground(%) Components 1 13. 00 Moisture Volatile oil 2 2. 61 3 Flavour compounds (relative concentration) Alpha pinene 1. 40 limonene 8. 30 Conventional ground(%) 11. 00 1. 15 0. 29 1. 18 13
2. Throughput of the mill Current required =6 A Working temperature =50°C Throughput of conventional grinding =22 kg/hr Throughput of cryogenic grinding =50 kg/hr i. e. throughput for cryogenic grinding is 2. 25 times more than conventional grinding 14
APPLICATION OF CRYO-GRINDING • recycling of composite materials • Thermoplastics • Thermo sets • Adhesives & waxes • Explosives • Spices 15
Hence we can conclude …. . 16
Thank you … 17
QUESTIONS ? ? 18
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