1. CRYOGENIC GRINDING

2. OBJECTiVES • INTRODUCTION • PROBLEMS IN CONVENTIONAL GRINDING • WORKING • ADVANTAGES OF CRYO GRINDING • EXPERIMENTAL STUDIES • APPLICATION

3. 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.

4. 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

5. 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

6. 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

7. Now….elimination of all these problems are required……..But………. HOW..???

8. Here comes the necessity of CRYOGENIC GRINDING…..also known as Freeze Grinding

9. 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.

10. 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

11. WORKING 06/09/2010

12. 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

13. RESULTS OF EXPERIMENTAL STUDIES 1. Volatile oil content & flavor component Example : pepper

14. 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

15. APPLICATION OF CRYO-GRINDING • recycling of composite materials • Thermoplastics • Thermo sets • Adhesives & waxes • Explosives • Spices

16. Hence we can conclude …..

17. Thank you …

18. QUESTIONS ? ?