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