Automated Flow Control Mechanism of Liquid Nitrogen in Cryogenic Grinding

Nagabhushan, E and Sudhir, V. and Sunil, C.R and Sunil, K. (2010) Automated Flow Control Mechanism of Liquid Nitrogen in Cryogenic Grinding. [Student Project Report]

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Abstract

This Dissertation / Report is the outcome of investigation carried out by the creator(s) / author(s) at the department/division of Central Food Technological Research Institute (CFTRI), Mysore mentioned below in this page.

Item Type:	Student Project Report
Additional Information:	Cryogenic grinding technique involves cooling a material below its embrittlement temperature using liquid nitrogen. Embrittled material grinds easily and very fine particle size is obtained. Compared to ambient temperature grinding, cryogrinding uses significantly less power to achieve substantial throughputs. The embrittlement temperature varies from material to material and correspondingly the amount of the cryogenic fluid fed should change The volume of liquid nitrogen is controlled pneumatically by regulating an air pressure valve. The project is aimed at automating the flow control of liquid Nitrogen based on the user specified temperature by designing a suitable embedded system. The flow-control is achieved by rotary action of the stepper motor which is coupled to the air pressure regulator valve. By continuous monitoring of the feedback temperature, the stepper motor is rotated accordingly to regulate the air pressure in order to attain the intended brittle temperature in the grinding zone to facilitate cryogenic grinding. The extent of automation involved in the project is such that the user just enters the required temperature using a personal computer and all the related operations are performed without any human effort. Once a particular temperature is entered, the system adjusts by itself the flow to reach the specified temperature and stabilizes by maintaining it, forming a feedback control system. The feedback control system is automated using a microcontroller based user friendly embedded system.
Uncontrolled Keywords:	Cryogenic grinding; liquid Nitrogen; automating, flow control
Subjects:	600 Technology > 05 Chemical engineering > 05 Unit Operations
Divisions:	Food Engineering
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	14 Jul 2010 09:50
Last Modified:	28 Dec 2011 10:16
URI:	http://ir.cftri.res.in/id/eprint/9555

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