Its my presentation on Standards of ventilation and natural ventilation . I made the presentation very easy so everyone can understand about it.

1. Standards of ventilation
&
Natural ventilation
By,
Siby Lalachan
(1AY17MI032)

2. WHAT IS VENTILATION?
Ventilation is mainly used to control indoor air quality by diluting and
displacing indoor pollutants; it can also be used to control indoor temperature,
humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of
indoor environment.
WHY VENTILATION IS REQUIRED IN MINING?
Whenever an underground mine is
opened , so many harmful gases are
produced in it due to various types of
activities which is introduced while
mining operation.

3. REASONS
Some of them are :-
• Gases come out with mining minerals.
• Pollution occurs due to uses of different machineries.
• Human employed in mine produces Carbon Dioxide while breathing.
• Oxidation of different materials present in mine, etc
And, human are employed in mine
they needed fresh air and also to
dilute or remove the harmful and
toxic gases from the working places.
And for this we have to make
arrangements of ventilation.

4. Standards of ventilation

5. Standards of ventilation
It shall be the duty of the owner, agent or manager of every mine to take such steps as
are necessary to constantly provide in all parts of the mine belowground which are not sealed off,
adequate ventilation to clear away smoke, steam and dust, to dilute gases that are inflammable or
noxious so as to render them harmless, to provide air containing sufficient oxygen and to prevent
such excessive rise of temperature or humidity which may be harmful to the health of persons.
(1)
(2) For the purposes of securing adequate ventilation as specified in sub-regulation (1),
the owner, agent and manager shall ensure that-
in every ventilating district, not less than 6 cubic meters per minute of air per
person employed in the district on the largest shift or not less than 2.5 cubic meters
per minute of air per tonne of daily output, whichever is larger, passes along the last
ventilation connection in the district which means the in-bye most gallery in the
district along which the air passes;
(a)
(b) at every place in the mine where persons are required to work or pass, the
air does not contain less than 19 per cent. of oxygen or more than 0.5 per cent. of
carbon dioxide or any noxious gas in quantity likely to affect the health of any
person;

6. (c) the percentage of inflammable gas does not exceed 0.75 in the general body of
the return air of any ventilating district and 1.25 in any place in the mine;
(d) the wet bulb temperature in any working place does not exceed 33.5
degrees centigrade, and where the wet bulb temperature exceeds 30.5 degrees
centigrade, arrangements are made to ventilate the same with a current of air
moving at a speed of not less than one meter per second; and
(e) for ensuring compliance with the provisions of clauses (b), (c) and (d) of this
sub-regulation, air samples and temperature readings shall be taken at least once in
every thirty days and the results shall be recorded in a bound paged book kept for
the purpose:
Provided that at any mine or part, where special conditions exist, the Chief Inspector
may, by an order in writing and subject to such conditions as he may specify therein, approve a
ventilation scheme in variance with the aforesaid provisions.
(3)
(4)
In every mine, ventilation as specified in sub-regulation (2) shall be produced by a
suitable mechanical ventilator.
If with respect to any mine or part thereof the Regional Inspector is of the
opinion that the ventilation is not adequate, he may by an order in writing, require
the installation and maintenance of such mechanical ventilator as is capable of
producing adequate ventilation in the mine or part.

7. Natural Ventilation

8. Natural ventilation
How natural ventilation produced?
Consider that a level roadway
joins two shaft equal in diameter and of
equal depth from a level ground surface. If
the air in both shafts is at same
temperature and pressure, there are two
columns of air equal in weight which
balance each other and there will be no
flow of air one shaft to the other.
We can create flow of air by
creating pressure difference of both shaft
and air start flow from one shaft to
another.

9. It can be produced by following factors:-
1.Presence of firedamp, or stream purposely introduced in one of shaft, which
renders the air lighter.

10. 2.Presence of fire in one of the shaft.
The fire heats up the air which has
then less density

11. 3.Passage of cold water down one of the shafts; the cold air is more dense

12. 4.Movement of case in the shaft

13. 5.Unequal depth of shafts.

14. Thank
You