293/2003 Coll.
DECREE
Dated 28 August 2003
On detailed conditions and characteristics of explosives intended for use in
hazardous conditions or in hazardous environments and testing properties of these explosives
Czech Mining Office, pursuant to § 28 paragraph. 1 of Law no. 61/1988 Coll., On
mining, explosives and the State Mining Administration, as amended
Act no. 315/2001 Coll .: | ||
§ 1
Subject Matter
Decree provides detailed conditions for the use of explosives
risk conditions or in hazardous environments, their properties and checking
properties of these explosives.
§ 2
Basic concepts
For the purposes of this Decree
A) mine safe explosives - explosives, detonating cord and detonators
based on the examination of the properties meet the conditions set out in the Annex to this Decree
,
B) risk conditions - such temperature conditions, when the temperature at the point of use explosives
higher or comparable with the temperature vzbuchu
sensitive explosives used in these conditions, ^ 1)
C) risk environments - environments where explosive gases or dusts
, or mixtures thereof [for example, coal mines with
potentially explosive coal dust ^ 2) or gassy mines ^ 3) using a
ordered mine safe explosives. ^ 4)]
§ 3
Detailed conditions for the use of explosives in hazardous conditions or
risk environment, their properties and testing these properties
listed in the Annex hereto.
§ 4
Permission to use mine safe explosives
(1) Permission to first use each type of mining explosives
safe in hazardous environments or in hazardous conditions ^ 5)
be issued after the manufacturer or importer (hereinafter the "applicant") shall submit
Czech Mining Office:
A) assessment of conformity with the essential safety requirements ^ 6)
prepared by an authorized person providing services in the scope defined in
decision on authorization for the conformity assessment of explosives by
special legal regulation, 7) | ||
B) a technical dossier containing instructions for using mine-safe
explosives, basic technical parameters identifying miner
explosive and its qualitative characteristics and finding
prepared by an authorized person ^ 7) that the miner explosive meets the requirements
listed in the Annex hereto,
C) the nature of the risk environment or risk conditions in which
to be mine-safe explosive used.
(2) The Czech Mining Office will assess the documentation referred to in paragraph 1, and in case of doubt
determine the extent of additional testing
properties by type of risk environment or hazardous conditions in
which should be mine-safe explosive used . This
testing requirements for mine-safe explosives listed in Annex hereto
authorized entity under a special law. ^ 7)
(3) on the results of any examinations the applicant shall submit
Czech Mining Office document (finding), which must be stated whether
kind of mine-safe explosive meets the requirements set out in the Annex to this
decree.
(4) Special parameters of mine safe explosives intended for use in
hazardous conditions and in risky environment must also be included in
instructions. These parameters must be met throughout
use.
§ 5
Repealing provisions
Repealed
First Decree no. 246/1996 Coll., Laying down detailed conditions for authorization
explosives, explosive objects and aids in circulation and
checking.
Second Decree no. 60/2002 Coll., Amending Decree of the Czech Mining Office
no. 246/1996 Coll., Laying down detailed conditions for authorization
explosives, explosive objects and aids in circulation and
checking.
Third CBU decree no. 14/1969 dated 20. 1. 1969 Ref. 112/14/69, which
approving the use fiberglass poles charging TOKOZ (reg. In the amount
25/1969 Sb.).
Fourth CBU decree no. 20/1969 dated 8. 4. 1969 Ref. 1313/20/69 laying
authorized to use mine ohmmeter type KN-66 (reg. In the amount of 25/1969 Coll.).
Fifth CBU decree no. 40/1969 dated 16. 6. 1969 Ref. 2800/40/69 fixing
Allows the use ohmmeter type MX-10 (reg. In the amount of 7/1970 Coll.).
6th CBU decree no. 2/1970 dated 26. 1. 1970 Ref. 5087/69/2/70 laying
approve the type of explosives warehouse M 200 (reg. In the amount of 7/1970 Coll.).
7th CBU decree no. 13/1970 dated 13. 7. 1970 Ref. 3777/5/70 laying
to apply for blasting operations in Czechoslovakia pneumatic charging equipment
marked Bunz 1 C (Reg. In the amount of 7/1971 Coll.).
8th CBU decree no. 9/1971 dated 10. 5. 1971 Ref. 2384/9/71 laying
to apply security detonator pliers BRK-7 (reg. In the amount
27/1971 Sb.).
9th CBU decree no. 14/1976, no. 26/1976 p. v. Czechoslovakia dated 19. 7. 1976 Ref.
4388/15/76 authorizing the use in blasting rock mining
explosive DANUBAL 1 (Reg. In the amount of 25/1976 Coll., Publ. In the amount
7/1976 p. V. Czechoslovakia ).
10th CBU decree no. 17/1979, no. 1/1980 p. v. Czechoslovakia dated 27. 12. 1979 Ref.
1565/17/79 tester for permission to use the igniters ZRKA-1 (Reg. In
13/1980 Coll., Publ. In the amount of 1/1980 p. V. Czechoslovakia).
11th CBU decree no. 22/1980, no. 7/1981 p. v. Czechoslovakia dated 26. 11. 1980 Ref.
811/22/1980 for permission to use pyrozapalovač (reg. 13/1981 in the amount
Coll., Publ. In Chapter 2/1981 p. V. Czechoslovakia).
12th CBU decree no. 19/1980, no. 9/1981 p. v. Czechoslovakia dated 28. 11. 1980 Ref.
4448/19/1980 for permission to use electric instantaneous detonators SO-anti
(reg. In the amount of 13/1981 Coll., Publ. In Chapter 2/1981 p. V. Czechoslovakia).
13th CBU decree no. 15/1982, no. 7/1982 p. v. Czechoslovakia on 1 7th 1982 Ref.
540/15/1982 for permission to use explosives warehouse type M 100 (reg.
In the amount of 21/1982 Coll., Publ. In the amount of 2/1982 p. V. Czechoslovakia).
§ 6
Efficiency
This Decree shall take effect on 1 October 2003, with the exception of the provisions
§ 5 points 1 and 2, which come into effect on the Treaty of
Czech Republic's accession to the European Union.
Chairman:
Prof. JUDr. Ing. Macarius, PhD. vr
Arrival.
The basic requirements for a mine-safe explosives intended for use
in hazardous conditions and hazardous environments, and their testing
Art. 1 miner explosives
I. Mine-safe explosive is divided into:
First dust that meet test explosions and their limit load
not cause ignition of a mixture of coal dust and air of concentration
300 gm-3,
Second anti, whose marginal load must not cause the ignition of the explosive
mixture of methane and air at a concentration of 8.5 to 9.5 vol.% and the coal dust
air concentration of 300 gm-3 and divided by the degree
security in three categories ^ 8).
A) Category I - anti-explosive tests that meet
explosion in the bore mortar with potentially explosive mixtures of methane and air
coal dust with air
B) II. categories - anti-explosives which satisfy tests
blast at an edge of the reflective wall mortar in explosive mixtures with air
methane and coal dust in air (flute wall mortars
enclose an angle with the reflective wall 45 c.); explosives must also recognize
deflagration in 11 attempts in a row, with an escape nozzle
about 3.5 mm, or initiating a critical mass of dust lay M50
50% chance of an explosive deflagration must be
larger than 18.0 g,
C) III. categories - anti-explosive tests that meet
mortar explosion on the edge of a reflective wall in explosive mixtures with air
methane and coal dust in air (flute wall mortars
form with reflective wall angles 0 st. and 90 st .); explosive must also not deflagrate during
stations 11 experiments in a row, with escape
nozzle of 2 mm in diameter or critical mass initiating cartridges dust
M50 50% probability induce deflagration of explosives must be greater than | || than 21.0 grams.
II. Testing and classification of mine safe explosives in explosive mixtures
First The test chamber (FIGS. 1-4) is a steel cylinder with a diameter of 1 700-2
000 mm and length of at least 5000 mm. On one side is firmly closed
flat steel wall (front chamber) with a closable opening
diameter 300-400 mm and the other open (when tested in methane-air mixture
closes visor). The center hole on the axis of the chamber.
Chamber is provided with a device for filling and mixing the mixture of methane
air, for efficient airing after various tests, sampling
Samples of explosive mixtures from the chamber for hanging bags with coal dust and
apparatus for registering explosion of an explosive mixture (registration
explosion of an explosive mixture can use a special device or hang in the chamber
electric wire with PVC insulation ) and measuring temperature and relative humidity
air in the chamber.
Second Cylinder bore mortar is made of steel or fiberglass 12,040.1 in
which houses a core of steel 16540.7 mortars, in which the axis of the bore
minimum diameter of 42 mm. The ratio of the diameter of the bore diameter of the infeed
explosives shall not be greater than 1.5. The length of the bore is determined by the length
test load so that between the mouth of the bore and the face of the first cartridges from
mouth was free uncharged space of at least 100 mm.
Fig. 1. Schematic diagram of the test chamber and location vývrtového mortars at
testing dust and protiplynových explosives Category I
Fig. 2. Schematic diagram of the test chamber and edge placement mortars at
testing protiplynových explosives II. and III. category
Third Edge mortar roller is made of steel 12060.4 diameter of 230 mm and a length of 1
000-2 000 mm over the entire length rectangular recess width
wall at least 90 mm. It is necessary that the length of the mortar being greater than the length of the test
charges.
Fourth The reflective wall is a steel plate with dimensions of at least 2000 x 1000 x
20 mm.
Fifth Chassis for the location of the edge or vývrtového pestle with a reflective
wall in the position of FIGS. 1 to 4
Fig. 3 Scheme of the test equipment during testing explosives II.
Category
Fig. 4. Scheme placement test equipment for tests of explosives III.
Category
6th Gas for preparing mixtures containing methane in% vol .:
Methane - at least 85
Homologues of methane (other hydrocarbons) - maximum 2
Unsaturated hydrocarbons and hydrogen - the most 0.2
Air (nitrogen, oxygen and CO2) - balance to 100
Carbon dioxide - the most 2
7th Coal dust on Physical chemistry:
Volatile combustible - at least 28%
Ash (A) - more than 7%
Water (W) - a maximum of 2.5%
Of particle size distribution:
- Sieve residue having a diameter of 0.5 mm - maximum 1%
- Sieve residue mesh diameter 0.071 mm - maximum 25%.
8th Aperture for closing the chamber with a mixture of methane from
paper, polyethylene films, etc.
9th Mining interferometer or another instrument for measuring methane concentration
an accuracy of +/- 0.5%.
10th Oxygen for measuring the concentration of oxygen in the air
intended for use in potentially explosive atmospheres and measurement accuracy of at least +/- 0.5%.
11th Electric instantaneous detonators intended for use in potentially explosive environments.
12th Mine blasting or other source of direct current
intended for use in potentially explosive environments.
13th Aspiration psychrometer or other device for measuring temperature and relative humidity
. It is necessary that the accuracy of temperature measurements was
least +/- 1 st. C and a relative humidity of less than +/- 2%.
Test Preparation
14th It is necessary to test charge was infeed from the same batch.
Weight test load is at least:
500 g for dust explosive
600 g for anti-explosive category I
400 g for anti-explosive II. and III. category.
Weight charge is determined by the nominal mass infeed.
Division infeed to the test is permissible.
15th The test load of the dust and protiplynových explosives I.
categories is placed in a mortar vývrtového to the bottom of the bore to
individual cartridges touched, and priming cartridges were first
from the mouth of the bore (bottom detonators heading for the bottom of the bore ). Required that
between the mouth of the borehole and test an explosive charge was space without
seals of at least 100 mm.
16th The test load protiplynových explosives II. and III. category
placed in groove edge mortars so that individual cartridges
touching each other, the center of the charge was at half the length of mortars, priming was first
cartridges from the front chamber and the bottom of the detonator directed to the aperture.
17th Tests were carried out at 5 to 30 st.
C and relative humidity of 60-90%. These values are verified by measurements in the chamber before
spit charges.
18th Wear vývrtového mortars (enlargement of the bore of the original volume)
Not be greater than:
25% - in tests for placing explosives on the market
50% - in control tests.
When testing is necessary to bore mortar rotated by 120 st. 1/3
set bore wear limit. The volume of the bore is measured by using water
and measurement containers.
19th Explosive mixture of coal dust with air to create different
auxiliary explosive cartridges 50 g, placed inside a paper bag
coal dust. Bag with dust is attached in the longitudinal axis
chamber so that the bottom was distanced from the ceiling of the chamber 500 +/- 50 mm and
its lateral surface being spaced from the front chamber of 1000 +/- 50 mm.
Mass coal dust (mp) in grams is determined by the relationship:
mp = 300 V
Where in the chamber volume (m3)
300 coefficient (gm-3).
Auxiliary cartridges is the same explosive and the same production series as a major test
charge. Delays between the various auxiliary and main charge
EUR 1 000-1 100 ms.
20th Explosive mixture of methane to air creates an impregnating gas into the enclosed chamber
delivery orifice and its mixing with the air so that the concentration of methane was
9 +/- 0.5 vol% and was the same throughout the chamber
. It is necessary that the oxygen concentration in an explosive mixture
was less than 18%. The methane and oxygen is checked by measurement before
spit charges.
Testing and evaluation
21st Tests of mine safe explosives are evaluated
statistical methods to evaluate the results of tests, and it
explosive mixture for each separately.
22nd In tests of the dust and protiplynových explosives Category
with bores with mortar charges placed against the hole from the outside
chamber, FIG. 1
23rd In tests protiplynových explosives II. and III. category
edge with mortar bomb is placed within the chamber so that between the end faces
mortar and the entire chamber or orifice being at least 1
000 mm, Fig. 2.
24th In tests protiplynových explosives II. category edge
mortar is rotated so that its walls at an angle of 45 st.
the reflective wall, Fig. 3. The distance from the apex of the reflective wall at a right angle
mortar is 460 +/- 10 mm, the vertical distance between the apex of the right angle
mortars and the ceiling of the chamber is 1050 +/- 50 mm and the vertical distance between the upper edge
reflective walls and ceiling of the chamber is 110 +/- 10 mm.
25th In tests of explosives protiplynových III. category edge
mortar is rotated so that its walls at an angle of 0 st. and 90 st.
the reflective wall, Fig. 4. Distance reflective wall from the vertical edge
mortar is 200 +/- 10 mm, the vertical distance between the horizontal edge
mortars and the ceiling of the chamber is 1050 +/- 50 mm and
vertical distance between the upper edge of the reflective walls and ceiling of the chamber is 110 +/- 10 mm.
26th The explosive is considered satisfactory if the number of igniting an explosive mixture
no more than a maximum allowable number of ignitions in Tables 1 and 2
listed in mathematical and statistical methods to evaluate the results of tests
. It is required to comply with the test sample with a probability of at least
P = 97.5% p = 5%, and that for explosives marketed by
Table. 1 and output explosive tests according to Table. 2. When
periodic testing of explosives is required probability of at least
P = 97.5% p <= 20% according to table 1.
Record test
27th A record of the test includes:
A) nominal diameter and weight infeed,
B) The method used for testing
C) the weight of the test load,
D) depreciation vývrtového mortars in%
E) the number of tests and the number of igniting an explosive mixture
F) nominal diameter test chamber
G) The temperature and relative humidity in the chamber,
H) the physico-chemical and particle size distribution of coal dust,
I) the concentration of methane in the explosion chamber vol.%.
III. Testing the resistance of mine safe explosives deflagration
Generally
Deflagration mine safe explosives (explosive burning explosives) is
detonation transformation whose speed is less than the speed of sound in the flue
explosion. Deflagration mine safe explosives
is an undesirable phenomenon and in environments with a potentially explosive mixtures of gases or dusts
significantly increases the risk of ignition.
Deflagration Resilience means the ability to withstand explosive
conditions favorable for the formation of deflagration.
METHOD AND
Principle
First The bomb tested explosive coal dust surrounded and closed in
steel tube with a nozzle to escape the fumes are prescribed manner
ignites. After the burn ignition composition and extinction of
sparked charges is determined by measuring the length of neodhořelé explosive charge.
Purpose and significance tests
Second Test determines whether the test is resistant to explosive deflagration and
qualifies for an assessment of its application with blasting
work in an environment with coal dust and methane.
Apparatus
Third On trial is necessary:
Steel tube (Fig. 1) of length 400 mm, outer diameter 57 mm, thickness 3 mm wall
. On the front side, the pipe has a steel cap with holes for inlets
glow plug and an escape nozzle which is attached to the tube
cap nut on the other side the tube is sealed steel
threaded stopper.
Escape nozzle opening
A) an average of 3.5 +/- 0.1 mm, is designed for testing explosives protiplynových
increased safety (II. Category) - Fig. 2a)
B) an average of 2.0 +/- 0.1 mm, is designed for testing explosives protiplynových
increased safety (III. Category) - Fig. 2b).
Coal dust on physico chemical composition:
Volatile combustible - at least 28%
Ash (A) - more than 7%
Water (W) - a maximum of 2.5%
Of particle size distribution:
- Sieve residue having a diameter of 0.5 mm - maximum 1%
- Sieve residue mesh diameter 0.071 mm - maximum 25%.
Ignition composition, prepared from 1 g of coal dust and 19 g model
anti-explosive with increased safety (III. Category) of the composition
:
Nitroglyceroglykol (ie. A mixture of nitroglycerin and
nitroglycol 3 + 2) 9.0 +/- 0.1%
Potassium nitrate 58.6 +/- 0.2%
Ammonium chloride 31.0 +/- 0.2%
Wood flour 1.0 +/- 0.1%
Silioxid 0.4 +/- 0.1%
Particle size of potassium nitrate and ammonium chloride, were used to prepare a model
explosives, may not be greater than 0.2 mm.
Ignition composition may be used within 3 months from the date of preparation.
Incandescent filament made from a 250 mm resistance wire diameter of 0.8 mm
example. Ni / NiCr. The resistance wire is coiled into 7 turns an internal diameter of 4 mm
. The total resistance of the glow plug is 0.9 to 1.0 Ohm.
End glow spirals are the front stopper decorated in ceramic bushings that
is sealed with plaster.
Quartz sand with a particle size from 0.25 to 0.50 mm.
AC power source with a current of 12 A, e.g. conversion
transformer 24/220 V
Ammeter with a range of up to 15 A.
Ohmmeter with 0-5 Ohms.
Stopwatch.
Fig. 1. Scheme kits for testing of deflagration
Fig. 2. Conduct exit nozzle
Test preparation charges
Fourth Explosive charge test length 200 to 300 mm forms 1-2 cartridges.
Fifth From the head of one of the cartridges collected meat explosives in a length of 20 mm.
Length cartridges thus prepared for the test was measured at three different locations
a length gauge steel with millimeter division with an accuracy of +/- 0.5 mm
, calculate the arithmetic mean and the result is indicated in mm.
6th The removed portion of explosives replacing 20 g ignition composition.
The test procedure
7th A steel tube closed steel stopper is poured
required amount of dry silica sand and it is placed in charge of the test
explosive prepared according to section 5-7, ignition folds upwards.
Charge is shroudings coal dust.
8th Up front closure with attached heating coil is inserted escape
nozzle hole corresponding to the respective category of test explosives.
Front cap is attached to the pipe so that the glow coil was completely immersed in
ignition composition. Screwing the cap nut assembly
closed.
9th Pipe bombs to be placed in a protected area in the vertical position so that the front
cap pointing upwards and pins glow plug through
ammeter connects the power insulated wire from the power source. From cover
turns electric current of 12 A, which was allowed 180 seconds
flow through the heating coil and observing the course of the test.
Had ceased development of fumes and assembly cools tube disassembled and cleaned after
Measure the length neprohořelé cartridges and determines whether occurred
Any point in the test cartridges for its burning by more than 20 mm.
Evaluation tests
10th To evaluate the test applies the rules of mathematical statistics
applied in statistical methods to evaluate the results.
Explosive is resistant to deflagration when the total number of test
load (n) is the number of charges, which has been burn-off load above 20 mm
(x) less than or the same as for the parameters P = 90% and p = 20%
shown in table 1 below. required to deflagration when explosive showed 11
experiments in a row, with an escape nozzle of 3.5 mm diameter for
explosives II. category as an escape nozzle of 2 mm diameter for explosives
III. category.
Record test
11th A record of the test includes:
A) diameter and weight infeed tested explosives
B) the results of individual determinations
C) evaluation tests
D) any deviations test methods.
METHOD B
Principle
First Test charge explosive located in a closed bore steel
mortars, is subjected to heat and pressure exposure to fumes, which
released by burning smokeless powder cartridges located in a bore in
certain distance from the test charge explosives. The intensity of the heat and pressure
exposure varies the weight of smokeless powder. Ignition of dust
el realized. igniter. After exposure, the borehole open and visually
evaluate whether there is ignition and burn explosive charge.
Purpose and significance tests
Second Test determines whether the test is resistant to explosive deflagration and
qualifies for an assessment of its application with blasting
work in an environment with coal dust and methane.
Third Test can determine the actual level antideflagračních properties
explosives.
Apparatus
Fourth On trial is necessary:
) Test Equipment - deflagration mortar, Fig. 3, is a steel forging
cylindrical steel 12060.4 minimum diameter of 220 mm and a length
1450 +/- 25 mm equipped throughout length of the bore in the roll axis.
Bore diameter is 42 mm. Bore on both sides by special seals
cap. It consists of a steel flange and tapered sealing liner.
Flange is tightened to the face of mortar 6 screws. For a perfect seal between the bore
forehead mortars and sealing taper plug inserted seal (eg.
Klingerit, Teflon). Used seals must withstand exposure to high temperature and pressure exhaust
deflagration. On one side of the bore is tapered sealing
liner equipped with glands for mains connection. the fuse. From the other side
bore is conical sealing insert is provided with safety diaphragm
serving to relieve pressure in the event of a deflagration to detonation transition.
Bore is provided with two holes, one at a distance of 200 mm from the front mortars
serving for mounting a sensor for measuring the pressure and the second at
300 mm from the same face, culminating in a high pressure needle valve
which is used to release the pressure after the termination of the experiment.
Fig. 3rd deflagration mortar
B) nitrocellulose smokeless powder type Lovex S 011-01
used to induce heat and pressure pulse.
C) the pressure sensor with a measuring range of 0 to 25 MPa, e.g. piezoelectric
Kistler type sensor for measuring pressure in a borehole (not necessary).
D) paper weighing from 70 to 80 gm-2 for the preparation of the test charges
explosives.
E) Thin tube diameter of 35 +/- 2 mm PE film weighing about
100 gm-2 for the preparation of smokeless powder cartridges.
Test preparation charges
Fifth The bomb test blast with explosives prepared by filling in a paper sleeve
40 mm diameter made of paper under Section 4. d). The explosive
filled into the tube at the same density as was the original náložkách
and faces charges were sealed folded.
6th To prepare test explosives used 100 g of explosives. For
explosives with a higher content of nitroesters will use half the amount of explosives, ie. 50 g
.
The test procedure
7th Smokeless powder is weighed with an accuracy of 0.1 grams filled into welded PE film
accordance with Section 4 e). El. igniter is then inserted into the dust so that its
pills were all immersed in dust and film undertakes
just above its surface.
8th Test charge explosive is placed into a bore mortar close to his mouth
. At a distance of 500 mm from the front load is placed smokeless cartridges
Dust electric supply conductors. the fuse is connected to the gland sealing
conical insert and the bore on both sides hermetically sealed.
Also closes the needle valve.
9th Contacts glands outside the device connects to the blasting and dust
ignites. The recording device monitors the pressure in the bore,
if the device is equipped with a pressure sensor.
10th After a sufficiently long waiting time, min. 20 minutes after the ignition
dust Carefully open the needle valve and release pressure in the bore. Then
a bore opens, pulls exposed explosive charge, if necessary. its remnants,
and carry out evaluation tests.
11th After each attempt to bore the head of mortars and sealing caps and clean
in the event of damage to replace the seal.
12th Unless otherwise determined by special requirements, the test must be carried out under the following conditions
:
Mortars temperature of 25 +/- 10 ° C. C
Relative air humidity of 70 +/- 25%.
13th If the conditions are complied with point 12 must be in the test protocol
given the actual parameters of the test environment.
14th When selecting samples for the test, the procedure
random selection.
15th The time between the preparation of samples for testing and its implementation
not influence the test results.
Evaluation tests
16th Test to detect explosives resistance deflagration expressed
critical mass of smokeless powder M50 required to elicit
deflagration.
17th Critical mass (M50) means the quantity of smokeless powder in
[g] that with 50% probability causes deflagration of explosives.
18th Mine-safe explosive II. category is resistant to deflagration
if a critical mass initiator lay dust M50 is greater than 18.0 grams
.
19th Mine-safe explosive III. category is resistant to deflagration
if a critical mass initiator lay dust M50 is greater than 21.0 grams
.
20th The evaluation of whether a deflagration explosive charge or not, the
done visually by the appearance of the test load, or recorded during
pressure in the bore.
21st During the test procedure according to the methodology of "Up and down" and change
the portion of smokeless powder. Recommended step is 1.0 grams.
Calculation
22nd Calculation of the critical mass of smokeless powder M50
required to induce deflagration is performed according to the formula
+ - - +
| A |
M50 = xo + d | - - 0.5 |
| N |
+ - - +
23rd Standard deviation is calculated with the following formula:
+ - 2 - +
| N x B - A |
S = 1.62 x L | ------------ + 0.029 |
| 2 |
| N |
+ - - +
Quantities N, A and B are given by the expressions:
kkk 2
N = sum of her total i.ni A = B = sum i .ni
i = 0 i = 0 i = 0
And individual symbols stand for:
X0 is the smallest mass at which deflagration was recorded,
i is the number representative of the number of steps from the smallest weight
d is the step size,
k is the index to the largest mass of dust in which was recorded | || deflagration,
it is the number of experiments at the weight of dust xi, where
was recorded deflagration.
Record test
24th A record of the test must contain:
A) identification and description of explosives
B) the date of manufacture of the test explosives
C) date of the test,
D) mortars temperature and relative air humidity during the test,
E) calculation
F) as a result of a critical mass of smokeless powder (M50) to 50%
chance of an explosive deflagration and its standard deviation
(s).
Note: For testing the resistance to the deflagration of explosives is
using method A; if the checking results
this method is unsuitable, a method B.
Satisfactory results with testing method B then
He considers crucial.
Miner explosives must also fulfill the requirements for the content of toxic fumes
explosion (CO + NOx) up to 50 dm3.kg-1 test
explosive under normal conditions (eg. Temperature 0 Wed C and a pressure of 101 32
psi) for detonating the detonator ability minimum standard no. 8, on
transmission of detonation and detonation stability.
Art. 2 miner igniting agents
I. Miner detonating
Miner detonating must have satisfactory resistance to ignition
explosive environment and its initiation cardinality must be sufficient to initiate
Mine safe explosives. Miner detonating cords must meet these requirements
checking:
A) the section of detonating cord lengths 4 m at both ends inserted into infeed
100 g mine safe explosives II. categories and horizontally hung in the detonation chamber
experimental tunnels, for example. according to Art. 1, Part II. Point 1
cartridges in paper or PE foil aperture is adjusted miner detonator.
When firing cord must be ignition of methane-air mixture
concentration of 9.0 +/- 0.5%. The test was performed with five samples.
B) Section cord length of 1 meter laterally adjusts miner
detonator and pushed into vývrtového mortar 42/1 200 mm located outside
detonation chamber test table so that the detonator was at the mouth of mortars.
When firing cord must be ignition of methane-air mixture
concentration of 9.0 +/- 0.5%. The test was performed with five samples.
C) The cord length of 1 meter at one end adjusts
mine safety fuse, the other end of the side rails lay
mine-safe explosive. Required to be in the shot detonating reliably
led to the detonation of explosive cartridges. The experiment was performed 3 times for each
mine-safe explosive contemplated to be used together with mine
safely detonating.
D) Detonating cords intended for use at elevated temperatures are tested,
that two sections of the cord length of 3 m is wound at a diameter of 10 cm and at three locations
outweigh tape. After storing for 3 hours at the desired temperature
use and the subsequent tempering at +20 st. C not at untangling cords
damage the packaging. Required that detonating
reliably detonated in initiating detonator # 8. The test is performed on two samples
.
II. Miner detonators
Miner detonators must exhibit the required degree of safety
against ignition of explosive atmospheres.
Checking mine detonators safe for use in explosive environments
.
Generally
First Safety detonators for use in hazardous environments means
such security is determined by the degree of sensitivity of detonators
ignite an explosive mixture of methane and air prescribed composition, under the conditions set forth
.
Second The temperature inside the detonation chamber throughout the test is maintained
range from 16 to 30 st. C. Other conditions set by the competent technical requirement test
kind of detonator.
Purpose and significance tests
Third From the test results, it can be judged whether the test shows the type of detonator
sufficient safety for use in mines or other workplaces
is a risk of an explosive mixture of methane and air.
Principle
Fourth The test detonator under the conditions specified below will bring an explosion and
determines whether it occurred in the explosion chamber or experimental gallery
small-box to the explosion of an explosive mixture.
Apparatus
Fifth To test the need:
A) For Method A:
detonation chamber experimental drifts, e.g. in FIG. 1, the steel roller
content circa 10 m3, length of at least 4000 mm, on the one hand, tightly closed
flat steel wall (bottom
detonation chamber). On the opposite side (mouth detonation chamber) closes
visor, required to maintain the explosive mixture in the chamber.
Fig. First test detonation chamber gallery
It is necessary that the detonation chamber devices for triggering detonators into
chamber for filling the methane mixing explosive mixture, sampling
explosive mixture and its effective airing after each ignition of an explosive mixture.
Detonation chamber can be equipped with sensors for registering
explosion of an explosive mixture, hangers thermometer and hygrometer. In the shell explosion
chambers can be portholes for observation and registration of accompanying events
during testing detonators.
B) For Method B:
Small-box with the detonation chamber 0.42 m3, is a steel sheet
open, without a wall, which aperture can be closed off.
Fig. 2nd Small-box
Box is equipped with a device for inserting detonators, filling methane, an explosive mixture
mixing, sampling explosive mixture and its effective
airing each time the ignition. Box can be equipped with sensors for registration
explosion of an explosive mixture, curtain for hygrometer and thermometer.
C) For methods A and B:
- Screen - is made of a material which retains an explosive mixture in
Detonation chamber and ignition of explosive mixtures in bursts, eg. Paper
PE-foil etc.,
- Blasting - cleared for mines with a danger of an explosive
environment or other suitable source of electrical current flow with the times
maximum of 4 ms; Tests el. detonators electric detonators suitable for
source of ignition,
- Instantaneous electric detonator with aluminum ferrules
to determine the sensitivity of the explosive mixture
- Gas for the preparation of an explosive composition containing in% vol .: methane least 85
homologs methane (other hydrocarbons) not more than 2 hydrogen and unsaturated hydrocarbons
more than 0.2 air (nitrogen, oxygen, CO2) residue 100
carbon dioxide exceeding 2
- Bottles for sampling an explosive mixture of methane and air,
- Interferometer or another instrument for measuring methane concentration
with an accuracy of +/- 0.3% vol.
METHOD AND
The preparation of explosive mixtures
6th Into the detonation chamber closed curtain is impregnated methane
such amount that its concentration in the chamber was maintained in the range of 8.5 to
9.5 vol.% Methane in air. Explosive mixture is thoroughly mixed so
to the entire volume of the chamber homogeneous.
Checking explosive mixtures
7th Content of methane in the explosive mixture was checked by appropriate
metanoměru, for example. Interferometer or infraanalyzátoru
with an accuracy of measurement +/- 0.3 vol.% Methane in air.
The test procedure
8th Before starting the test must detonation chamber
rid of all the impurities. After closing the aperture is filled with methane in an amount corresponding to the desired composition
explosive mixtures in paragraph 6. The temperature in the detonation chamber
corresponds to the provisions of section 2.
9th The test detonator is placed in a detonation chamber vertically so that
located approximately in the middle of the width and length and 2/3 the height of the chamber.
Before firing first, fifth and tenth test detonators in a series of 10 detonators fired individually
explosive mixture and mix a check made
its composition according to claim 7. Upon mixing of the explosive mixture
detonator to explode. In one chamber is full explosive mixtures can
described individually tested 10 detonators.
10th After testing a series of 10 detonators and after the test is performed
aluminum detonator firing in the explosion chamber, where it is required to occur
perfect explosion explosive mixture. If no explosive mixture
brought aluminum detonator to explode, do not recognize the results of the tests
valid.
Evaluation tests
11th Result of tests to evaluate the statistical methods
evaluation of test results by reliability coefficients P ap
listed in the technical requirements of the test detonators.
Detonator meets the conditions of the tests, if the total number of samples tested
(n) is the number of samples in which there was a spark (x)
lower or equal than shown in Table. 1 Mathematics and statistics
methods for evaluating the test results for the required parameters P ap
otherwise suitable. Required to comply with the test samples with
probability of at least P = 95% and p = 10%.
METHOD B
12th Proceeding as in method A except that instead of the detonation chamber
experimental tunnel used small-box.
Record test
13th A record of the test includes:
A) data about used test equipment
B) temperature and relative humidity of the air test area,
C) the number of tests and the number of igniting an explosive mixture
D) the nature and degree of timing detonators.
Note: A test method is mandatory for testing mine
safe detonators for use in explosive environments.
Test Method B is informative.
Art. 3 statistical methods to evaluate the results of tests
The evaluation
Statistical methods to evaluate the results of tests can be applied in cases
if it is to be verified that the samples tested
meet the conditions of the tests, with the proviso that the probability of unsatisfactory result
exceed p%, while the estimate this upper limit has to be made with the probability P
%.
Reliability coefficient P claim APV percentages may be selected from
Table. 1 in which the selected coefficients are the probabilities
number of attempts (n) assigned to the maximum permissible number
unsatisfactory results (x).
Table. 1
----------------------------------------------- --------------------------------
p% P% -------
-------------------------------------------------- ----------------------
80 90 95 97.5 99.5
-------------------------------------------------- ---------------------
xnxnxnxnxn
---------------------------------------------- ---------------------------------
20 0 8 0 11 0 14 0 17 0 24
1 14 1 18 1 22 1 26 1 34
2 21 2 25 2 30 2 34 2 43
3 27 3 32 3 37 3 41 3 51
4 33 4 38 4 44 4 48 4 59
5 39 5 45 5 50 5 55 5 66
------------------------------------- ------------------------------------------
10 0 16 0 22 0 29 0 36 0 51
1 29 1 38 1 46 1 54 1 72
2 42 2 52 2 61 2 70 2 90
3 54 3 65 3 76 3 85 3 106
4 66 4 78 4 89 4 100 4 122
5 78 5 91 5 103 5 114 5 137
------------------------------------- ------------------------------------------
5 0 32 0 45 0 59 0 72 0 104
1 59 1 77 1 93 1 110 1 146
2 85 2 105 2 124 2 142 2 182
3 110 3 132 3 153 3 173 3 216
4 134 4 158 4 181 4 202 4 248
5 157 5 184 5 208 5 230 5 279
-------------------------------------
1 ------------------------------------------ 0161 0230 0 299 0 368 0 528
1 299 1 388 1 473 1 555 1 740
2 427 2 531 2 628 2 720 2 924
3 551 3 667 3 773 3 874 3 1,094
4 671 4 798 4 913 4 1,022 4 1,256
5 790 5 926 5 1,049 5 1,164 5 1,411
------------------------------------- ------------------------------------------
Where P% reliability allegations that the probability
the occurrence of unsatisfactory results does not exceed the specified
limit pv%
p upper limit of the confidence interval for
the probability of unsatisfactory results
experiment in%
n number of consecutive attempts in a series
x allowable number of experiments which will
the unsatisfactory outcome marks in a series of attempts
Table no. 2
----------------------------------------------- --------------------
p% P% -------------------
------------------------------------------------ || | 90 95 97.5 99.5
-------------------------------------------------- ---------
xnxnxnxn
---------------------------------------------- ---------------------
20 1 1 1 1 1 1 1 1
2 3 2 3 2 2 2 2
3 7 3 5 3 4 3 3
4 10 4 8 4 7 4 5
5 14 5 11 5 10 5 8
6 17 6 15 6 13 6 10
7 21 7 18 7 16 7 13
8 25 8 22 8 20 8 16
--------------------------------------- ----------------------------
10 1 1 1 1 1 1 1 1
2 6 2 4 2 3 2 2
3 12 3 9 3 7 3 5
4 19 4 15 4 12 4 9
5 26 5 21 5 18 5 13
6 33 6 28 6 24 6 18
7 40 7 35 7 30 7 23
8 48 8 42 8 37 8 29
--------------------------------------- ----------------------------
5 1 3 1 1 1 1 1 1
2 11 2 8 2 6 2 3
3 23 3 17 3 14 3 8
4 36 4 29 4 23 4 15
5 50 5 41 5 34 5 24
6 64 6 54 6 46 6 33
7 79 7 69 7 58 7 43
8 94 8 83 8 73 8 54
--------------------------------------- ----------------------------
1 1 11 1 6 1 3 1 1
2 54 2 36 2 25 2 12
3 111 3 83 3 64 3 35
4 176 4 139 4 111 4 70
5 245 5 200 5 165 5 111
6 317 6 264 6 223 6 158
7 392 7 332 7 285 7 208
8 468 8 402 8 349 8 262
--------------------------------------- ----------------------------
Method of evaluation according to Table. 1 requires, particularly for higher reliability
claims relatively large number of experiments, it is therefore required
Evaluation for approval tests during the (first)
placing on the market, or tests of the same severity. The method also in the approval
tests admits the occurrence of a limited number of unsatisfactory results
over a specified number of attempts, the number of permissible nonconforming
results in different types of tests may be limited in advance, for example.
On two unsatisfactory results in the third occurrence in the test
been discontinued.
During routine examinations approved product should be checked whether
avoid a change in the quality of the product or test conditions, when
which the product can no longer be regarded as satisfactory. Evaluation is
be carried out at the same reliability coefficient P ap by
table no. 2, which carried the numbers of experiments (n) assigns the maximum admissible number
unsatisfactory results, in which the product is not to be regarded
unsatisfactory. Evaluation according to Table. 2
required particularly for the final examination for explosives relative
security is not required but the test results of the same parameter u
same product totalized long (preferably from 1 1 to 31 12.
current year) match the values in table No. 2.
Example:
Miner explosives and approval tests on the relative
mine safety in methane-air mixture at the weight load 1000 g
posted to the proposed P = 97.5% p = 5% satisfactory results (ie. 0 || | ignitions / 72 attempts event. 1 inflammation / 110 attempts event. 2 inflammation / 142
attempts). Thus, it was with 97.5% confidence demonstrated that the possibility of inflammation
methane mixtures with charge 1000 g of not more than 5%.
In tests of final inspection, carried out under the same conditions was achieved
:
First Prod. file - burnt 2/6 attempts
Second Prod. file - 0 ignitions / 6 attempts
Third Prod. file - 1 inflammation / 6 attempts.
The result is not yet satisfactory (3 burnt / 18 attempts).
Miner explosive B approved under the same conditions, reported a
output control tests the following results:
First Prod. file - burnt 2/6 attempts
Second Prod. file - burnt 2/6 attempts.
Although each file separately are satisfactory overall result is not satisfactory
(total 4 burnt / 12 attempts), it is necessary to interrupt production and
examine the production process and event. test conditions.
Before further manufacturing (e.g. after the deficiencies in the manufacturing process
) are to be checked for explosives ranging indicator
probability P = 97.5% p = <20% according to Table. 1. In
case adjustment of physical properties (e.g. particle size component explosives
etc.) must also check the content of toxic fumes
explosion, detonation capacity, transmission of detonation, and the detonation velocity.
1) For example, § 89, 167, 171 of Decree no. 72/1988 Coll., On the use of explosives
.
2) § 152 of the Decree No.22 / 1989 Coll., On health and safety at
and operational safety in mining activities and in conquering
unrestricted minerals underground.
3) § 79 of Decree no. 22/1989 Coll., As amended by Decree no. 330/2002 Coll.
4) § 87-129 Decree no. 72/1988 Coll.
5) § 28a par. 2 Act no. 61/1988 Coll., On mining activities,
explosives and the State Mining Administration, as amended by Act no. 315/2001 Coll.
6) § 12 of Act no. 22/1997 Coll., On technical requirements for products and
amending and supplementing certain acts as amended by Act no. 71/2000 Coll. and
Act no. 205/2002 Coll.
7) § 11a of the Act no. 22/1997 Coll., As amended by Act no. 71/2000 Coll. and Act No.
. 205/2002 Coll.
8) § 108 et seq Decree no. 72/1988 Coll.
