CMR 2017 (Ventilation) Quick Revision
CMR 2017 (Ventilation) Quick Revision
In this article, an attempt is made to summarise some
important regulations of the Ventilation chapter (Chapter XII) of CMR, 2017 in
an easy to read and understand language so that one can do a quick revision (Although
it is advised for anyone to gave gone through the regulations in their original
form before reading the summary):-
Reg. 153. Standard of ventilation–
(1) The owner, agent, and manager shall ensure that-
(a) Air
quantity ≥ 6 m3/min per person employed in the district on the largest
shift or Air quantity ≥ 2.5 m3/min per
tonne of daily output, whichever is
larger, passes along the last ventilation connection in the district.
(b) Oxygen
percentage in air ≥ 19%
Carbon Dioxide percentage in air ≤ 0.5% or any noxious gas in quantity likely to
affect the health of any person
(c) Inflammable
gas(mainly CH4) percentage ≤ 0.75% in the general body of the return air and Inflammable
gas(mainly CH4) percentage ≤ 1.25% in any place in the mine
(d) Wet Bulb
Temperature(WBT) ≤ 33.5o centigrade, and if WBT is > 30.5o centigrade, then airspeed ≥ 1m/sec
(e) Air
samples and temperature readings shall be taken at least once every 30 days
and the results
shall be recorded to ensure compliance with clauses (b), (c), and (d).
But where special conditions exist, the Chief Inspector may
approve a ventilation scheme which may differ from the above provisions by an
order in writing, subject to such conditions as he may specify therein.
(2) Mechanical
ventilator is compulsory for every belowground mine.
(3) If
according to the Regional Inspector the ventilation is not adequate, he may
require the installation and maintenance of such a mechanical ventilator as is
capable of producing adequate ventilation in the mine or part.
Reg. 154. Main mechanical ventilator(MMV), its drive, and
fittings.–
(1) Every main
mechanical ventilator’s distance from the opening of the shaft or incline at
any point
≥10 meters.
(2) Electricity
supplied to the MMV will be through a separate circuit than that of the mine.
(3) Two
different sources of power to be provided for the MMV.
(4) Pressure
recording instrument near the MMV.
(5) Reversal of air has to be possible.
(6) Air Lock to be constructed at shaft or incline where person or material are transported.
Reg. 155. Restriction on installation of mechanical ventilator belowground.–
(1) No booster
fan in fiery seam or II and III degree gassiness seam, unless manager is
satisfied that it is necessary after ventilation survey in parts likely to be
affected.
(2) And 7 days
prior notice is to be given to Regional Inspector before such installation.
Reg. 156. Installation and maintenance of mechanical ventilator.-
(1) Mechanical
ventilator and booster fan shall be examined every 7 days
(2) Quantity
of air shall be measured every 14 days at every main intake and return, split,
and ventilation district.
But in case of non-fiery seam or degree I gassy seam, the
quantity can be measured every 30 days.
Reg. 157. Standing orders.–
(1) For every ventilator belowground except auxiliary fan, the manager shall submit standing orders specifying the action that shall be taken with respect to the withdrawal of persons from the mine or part thereof within a period of 30 days of the installation to the Regional Inspector,
(2) The
Regional Inspector may approve or require some alterations.
(3) A copy of
the standing orders in suitable language shall be displayed at conspicuous
places in the mine, both above and below ground.
Reg. 158. Splits and airways.–
(1) Mine shall
be divided into districts to ensure separate and independent current of fresh
air.
(2) The intake
shall be so arranged as to travel away from stagnant water.
(3) Districts
shall have two independent intake airways, one of which shall be for traveling.
However, Regional
Inspector may exempt from this requirement in special conditions.
(4) At least
two doors shall be provided between the main intake and main return airway
connection if it is not sealed.
Reg. 159. Brattices, doors, stoppings, and air-crossings.–
(1) Any doubt
about the adequacy of these ventilation devices shall be settled by Chief
Inspector.
(2) The space
between the frame of every ventilation door and the roof and sides of the
roadway shall be built up with masonry or concrete, not less than 25
centimeters in thickness.
(3) Ventilation
doors shall be self-closing.
(4) If passage
through doors is frequent, there shall be a door attendant.
(5) Ventilation
stopping thickness:
a) If not reinforced:- not less than 25cm
b) If reinforced:-
not less than 15cm
(6) In case of
a mine having problems of fires or spontaneous heating along with the working
of coal seams of degree 2 or degree 3 gassiness, the Chief Inspector may
require the construction of explosion-proof ventilation stoppings at such
places as may be specified by him.
(7) The
thickness of partitions and walls of air-crossings
a) If not reinforced:- not less than 25cm
b) If reinforced:- not less than 15cm
(8) Examination of every airway, air crossing, and door shall be done once at least 14 days
Reg. 160. Velocity of air current–
|
Degree of
gassiness |
Place where velocity
of air is to be measured |
Velocity of air
(m/min) |
|
First, second or third
degree |
Immediate outbye
ventilation connection from the face. |
30 |
|
First or second
degree |
(i) 4.5 meters from any face
whether working or discontinued on the intake side of the brattice or |
30 |
|
|
partition. (ii) 7.5
meters outbye of the discharge end of an air pipe. (iii) At
the maximum span of a longwall face. |
15 60 |
|
Third degree |
(i) 4.5
meters from any face whether working or discontinued on the intake side of
the brattice or partition. (ii) 7.5
meters outbye of the discharge end of an air pipe. (iii) At
the maximum span of a longwall face: |
45 25 75 |
Reg. 161. Auxiliary fans.-
(1) Should
supply adequate quantity of air within 3 meters of the face or blind end.
(2) Conditions
for installation of two or more auxiliary fans in the same ventilation district
shall be specified by the Chief Inspector.
Reg. 162. Precautions against fire in ventilation appliances.-
(1) Fireproof housing for the mechanical ventilator.
(2) In the case of every fan other than an auxiliary fan,
the coal or other carbonaceous material exposed in the sides, roof, and floor
shall be covered with masonry or other fire-resistant sealant as protection
against fire, for a distance of not less than 5 meters in every direction from
the fan
Reg. 163. Ventilation plans to be brought up-to-date.–
(1) When any major alteration in ventilation system (like
erection of stopping etc), the ventilation plans have to be brought up to
date
Reg. 164. Obstructions, interruptions, and alterations.-
(1) No
material or debris shall be allowed to accumulate in any level, drive,
crosscut, roadway, or any other part of the workings below ground so as to
impede the ventilation.
(2) Every
roadway and working belowground which is not adequately ventilated shall be
fenced or barricaded so as to effectively prevent persons entering the same.
Reg. 165. Precautions against gas during de-watering and
re-opening.-
(1) Dewatering
or reopening operations shall take place under the supervision of a competent
person.
(2) During
such operations, Safety lamps shall be used.
Reg. 166. Precautions against inflammable and noxious gases.–
(1) For the purpose
of this regulation, inflammable gas shall be deemed to have been found or
detected when it is indicated:-
Degree 1 gassiness:- 0.1% of CH4 Degree 2 gassiness:- 0.5%
of CH4 Degree 3 gassiness:- 1.25% of CH4
(2) If gas is detected in any part of mine persons are to be
withdrawn and the place shall be fenced immediately.
Reg. 167. Inspection of unused working for gas.–
(1) Unused workings shall be inspected every 7 days in 2,3
degree gassiness or fiery seam and results of such inspections shall be
recorded
Reg. 168. Safety lamps to be used in belowground mines.–
(1) Only approved lamps or lights shall be used or permitted
to be used belowground in any mine.
Provided that the Chief Inspector
may exempt any mine or part thereof from the operation of this regulation under
special conditions.
Reg. 169. Determination of percentage of inflammable gas and of environmental conditions.-
(1) Approved apparatus to be used for the
determination of inflammable gas percentage.
(2) Gas
samples to be analyzed within 3 days of taking them.
(3) Determination
of CH4 percentage shall be made once every 7 days:
a) If
determination shows CH4 > 0.8%, determination shall be made every 24 hrs
b) If
determination shows CH4 < 0.6%, determination shall be made every 30 days
(4) After any
alteration in the ventilation system is done, the determination of CH4
percentage shall be made within 24 hrs
(5) Power
supply to be cut if CH4 > 1.25%
Reg. 170. Monitoring devices.-
(1) The Chief
Inspector may require approved environmental monitoring devices to continuously
record information regarding environmental conditions to be installed
belowground.
(2) The chief
inspector may also require analysis of mine air samples by gas chromatography
or other equivalent technique.
Reg. 171. General precautions in gassy mines.–
(1) Extension
of gallery not more than 3m from ventilation connection, unless current of air
is coursed up to a point within 3m of the face by means of brattice, tubes,
etc.
(2) No narrow
main or advance gallery shall be driven more than three meters ahead of the
widened gallery.
(3) Every
stopping shall be substantially built and every air crossing should be able to
withstand an explosion.
(4) Air
current which ventilates goaved or disused area, shall not ventilate working
face.
(5) No major
alteration in the ventilation system shall be made without permission of the
Regional Inspector
Reg. 172. Contrabands.–(It means items which are illegally
imported)
(1) In
belowground mines, No person shall have any cigar, cigarette, biri, or other
smoking apparatus, or any match or mobile phone or other unapproved apparatus
of any kind capable of producing a light, flame, or spark in his possession.
(2) A
competent person shall be authorized to check every person going in mine for
contrabands.
Reg. 173. Underground relighting stations.–
(1) In every mine, lamp stations for relighting safety lamps
may be fixed by the manager at suitable places belowground and every such
station shall be marked RELIGHTING STATION, which shall be situated in a main
intake airway, and shall be placed in charge of a competent person.
Post a Comment