From ventilation Book

2. INTRODUCTION
 Title :Heat source in mine .
 Name :Muhammad Owais Afridi
 REG#:13PWMIN0691.
 Semester :8th
 Department: Miningengineering.

3. Sources of heat in mine:

4. Heat sources in mine :
 There are eight potential sources of heat in mine
.
 Several or all may contributes heat to
underground environmental condition.
 1)adiabatic compression in shafts and near
vertical openings
 Very similar to the effect of gas in compressor
,air entering a mine into shaft and heat is flow
downward. if no interchange in the heat or
moisture of air. Air takes place in the shaft, the
compression takes place adiabatically

5. continuo:
 The rate of increase in temperature is nearly
constant and it is approximately 5.5 ºF per
1000 feet
 2)ROCKS SURROUNDING OPENINGS
 The temperature of sub surface rock rises
steadily with depth .
 In most climate , the rock temperature
ceases to be affected by surface
temperature and is taken as constant for
reference at about 50ft beneath surface.

6. Continue:
 It than increase with depth at approximately
a uniform rate in a given local called
geothermal gradient.
3] Metabolism in human being:
 Chemical and oxidation processes within
human body called metabolism produce
much heat.
 This is liberated from the body into the air by
convection ,radiation or evaporation.

7. Continue:
 The amount of heat liberated by a man is
depend upon the man activity and the
environmental condition .
 It may vary from 400Btu/hr for a man to
800Btu/hr for man working.
 4)Oxidation:
 Oxidation of timber and mineral can produce
heat in the mine .
 In the coal mine they may consist 80% to 85%
of the total load.

8. Continue:
 In ore mine having a high sulfide content the
liberation of heat is too high and some time
causes hazard fire.
 5) Machinery and light:
 All the inefficiency in the power operated machine
is called power losses ,these power losses directly
or indirectly converted to heat through friction.
 Compressor , ITC causes the heat in mine .
 The heat produce by lighting lamp is generally
small .carbide lamp liberated 200 Btu/hr heat
while safety lamp is less.

9. Continue:
 6]blasting:
 Half of the heat in mine is produce by the
detonation of high explosive.
 This is usually a significant cause of
temperature rise in mine.
 Blasting during off shaft or lunch time
minimize this effect.

10. Continue:
 7]Rock movement:
 Movement of ground due to geologic causes or
mining subsidence is another source of heat .
 Caving or collapse of waste or ore in stops area
is the common cause of heat liberation due to
ground movement.


11. Continue:
 8}Head losses in Air way:
 All the friction and shock losses in air flow is
converted in heat in mine .
 All the static head in mine is converted in heat
in mine.

12. Thank you.