Development of experimental stand for research of foci of self-heating in free-flowing environments

Abstract

For study the conditions of occurrence and rules of the development of foci of self-heating in friable media, including cacked, a pilot booth for identifying mutual correlation of thermo-physical characteristics of the investigated medium and external parameters has been elaborated. The stand allows managing processes in the test environment: to provoke the emergence of self-heating hearths and vary the intensity of their development, and to record the spatial-temporal distributions of temperature and humidity which restore interesting features of the environment. Capacity for studying the granular medium is a vertical cylinder where the axisymmetric problem is implemented due to emergence of self-heating chamber in the thickness of the medium being studied – on the axis of the container symmetry. The center is created at the specified location by the granular medium of delivery of moisture by the special channel and heating the given place to the desired value. Heat removing from the source of self-heating is carried out at the expense of transfer of heat the coolant located in the heat taking tube. The heat taking tube is placed inside the heat sink system which is a sectional tube that is installed in the thickness of granular material under study. To eliminate uncontrolled flows of heat from self-heating chamber for heat removal system the pipe section located outside the chamber provoking self-heating are made of material with low thermal conductivity. The section located in the focal zone is made of high thermal conductivity material. To improve the thermal contact between the tube and the inner heat taking surface thermally conductive heat sink section the intermediate coolant system has been used. Contact of intermediate coolant in the space between heat taking tube and the inner surface of the thermally conductive heat sink section of the system is automatic when removal from the source of self-heating heat is necessary.