"paul smith purses " Basic theoretical knowledge o

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Basic theoretical knowledge of mine ventilation air
Section Chapter mine mine mine
the main component of the air mainly by air oxygen (O2), nitrogen (N2), carbon dioxide CO2 composition, their volume percentage is 20.96%, respectively, 79%, 0.04%
an oxygen (O2)
colorless, tasteless, odorless gas, is heavier than air (relative density of air is 1.05) to combustion and to help people breathe.
oxygen concentration of not less than 20%;
in general, the oxygen demand in the rest of 0.2 ~ 0.4L/min; at work when the oxygen is 1 ~ 3L/min.
O2 concentration of 17% of the rest had no effect on the work of breathing difficulties
15% strong heartbeat and breathing, rapid heartbeat, inability to work
10-12% when the loss of consciousness, coma, life-threatening
6-9% when a short loss of consciousness, respiratory arrest, death
two nitrogen
colorless, tasteless, odorless inert gas, the relative air density is 0.97, mine is mainly used for fire fighting .
mainly from underground mines in the blast, and the decay of organic matter in the emission coal.

Third, carbon dioxide CO2
CO2 colorless, Luedaisuanwei gas, heavier than air and often accumulate in the roadway floor, soluble in water, slightly toxic. When the higher concentration of CO2 in the air will reduce the O2 concentration asphyxiation.
main sources: personnel respiration, oxidation, combustion, explosion, coal and rock in the pouring
airway, the concentration of more than 0.75% must immediately identify the reasons for processing; mining area return airway, mining face return airway concentration more than 1.5%, the mining face airflow at 1.5% concentration, must be stopped work, the withdrawal of personnel, measures to deal with.
four mine detection methods
air sampling analysis by gas chromatography in the laboratory, precise but complicated to operate for a long time, generally used for detection of underground fire area or need to accurately determine composition of the air component of the occasion.
Rapid Determination portable devices (O2); than the long tube-type II mine detection of harmful gases in the air of harmful gases in the mine
have carbon monoxide (CO), hydrogen sulfide (H2S), sulfur dioxide (SO2) , nitrogen dioxide (NO2), ammonia (NH3), hydrogen (H2), methane (CH4) and so on.
one, mine air of harmful gases and their basic properties
(a) carbon monoxide (CO)
basic nature of the colorless, tasteless, odorless gas, the relative density of air is 0.97, slightly soluble in water, fire, explosion (13-17%).
are highly toxic; human hemoglobin in the blood and the affinity of CO and oxygen affinity than it 250-300 times a large.
concentration of 0.016% after a few hours, headache, heartbeat, ringing in the ears and other minor symptoms
0.048% 1H poisoning
0.4% within a short period of slight loss of consciousness, seizures, death within 30 minutes
1% of the 1-3 minutes it will die
poisoning symptoms there was a cherry red mucous membranes and skin
the main source of mine: blasting, mine fire, gas and coal dust explosion (explosion concentration up to 2 -4%). According to statistics,"the cat puma ", in mine fire, gas and coal dust explosion in a staff of about 70% -75% of deaths are caused by CO poisoning.
density is 1.19, soluble in water, when the concentration of 4.3% -46% of the explosive. Are highly toxic, the blood oxygen while the eyes and respiratory tract have a strong stimulating effect, can cause pulmonary edema.
the main source of mine: rotting organic matter, sulfur mineral water.
, a highly toxic, are miners known as the
SO2 + H2O = H2SO3
the main source of mine: the oxidation of sulfur minerals and burning sulfur coal in the emission.
soluble in water (generated nitric acid) can cause pulmonary edema.
the main source of mine: explosives.
the hydrogen concentration should not exceed 0.5%
.
Second, measures to prevent harmful gases endanger
(1) to enhance ventilation (2) to strengthen inspection (3) gas extraction (4) use of water cannons blasting spray or mud
(5) strengthen management; closed set specification (6) to carry self-help (7) Emergency weather conditions

Section underground underground underground climate is air temperature, humidity, wind speed and integrated the three people given the comfort level of
1, the temperature
℃, K,
T = 273.15 + t
downhole temperature by surface temperature, temperature of the rock formation, oxidation and heat and water evaporation absorbs heat, air compression and expansion, ventilation intensity factors into the warm air cool in summer and winter routes

2, humidity
(1) absolute humidity fa (g/m3)
(2) relative humidity
= 100fa/fs,%
when = 0 for dry air; when = 100% saturated air; fa2
W = W1-W2 = Q1 × fa1-Q2 × fa2
= 1000 × 17.56-1100 × 12
= 4360g/min
= 4360 × 60 × 24
= 6.3t / d
air density: the unit volume with the quality of the gas, Kg/m3.
wet air from the dry air and vapor composition, its density ρ is the mass per unit volume of gas has, Kg/m3.

t-wet measured air temperature ℃;
Ps, P-saturated water vapor of the absolute pressure,"short prom dresses 2011 ", moist air is absolutely static, Pa.

temperature measurement requirements:
1, heading face, the face should be 2 meters away from the head back in the romantic;
2, longwall face, return airway from work face 10 to 15 meters back to the romantic in;
3, mechanical and electrical chamber, chamber air return crossing back to romantic in;
4, the temperature of the measuring point should be close to the body, heat or refrigeration equipment, at least distance of 0.5 m;
temperature measurement of time, generally from 8:00 to 16:00 time frame.
mine ventilation
Section Chapter the basic task of
mine ventilation air continuously into the mine to the ground, while the air pollution discharge process is well outside the mine ventilation

The basic task of mine ventilation:
(1) an adequate supply of fresh air underground
(2) exclude or dilute the toxic gases in mines and dust
(3) to create a good working environment
(4) improve the resilience of the mine tunnel airflow
division:
1, divided roadway romantic: a stand of roadway from the end of each bracket and Lane roadway space of 50mm romantic; no stent (shotcrete, puzzle Xuan) roadway from the tunnel top, bottom, to help the roadway space for the 200mm romantic.
2, Merry coal face: from the coal wall, top and bottom of the 200mm (less than 1m of thin coal seams to 100mm) and gob cut top line as the boundary of the range of romantic work the coal face.
3, the coal face back to the romantic: coal from the coal face of coal mining beyond the 10m line the wall face return airway airflow.
4, heading face romantic: the heading face to the duct exit this section of roadway romantic.
5, heading face back to the romantic: the heading face return air side of the tunnel exit duct romantic.
6, mining face local accumulation of gas: beyond the romantic mining face, the gas concentration to 2% of its volume more than 0.5m3 of space gas accumulation.
7, a location 20 m (10m) near the Merry: refers to a location on the lower of 20 m (10m) romantic.
Section
mine mine ventilation system ventilation system ventilation is mine, the main fan of the working methods, ventilation and ventilation network
a general term, ventilation fans ventilation is the main work method, and a draw-out, push-type, mixed type.
ventilation is the ventilation shaft and into the return air shaft arrangement, a centralized
(tied, points out)
diagonal (wings, partition)
type
mixed region type
network is: romantic connection through the form of roadway
series parallel diagonal
Second, the coal face ventilation:
1) U-type back style has the advantage of simple, reliable, leakage is small, on the corner gas drawback is easily overrun. To strengthen the gas detection, using wind screens or other ventilation devices to prevent gas build-up limits.
U-based systems ahead of the forward roadway, its ventilation and the length of the short head alone; drift maintenance less time; Lane offshoot in good care, air leakage is not significant, there are certain advantages. In addition, U-forward style gob gas is not flock to the face, while the flock back to the wind drift. But U-forward style than retreating big gob of air leakage, the effective face amount of wind is small, and the prevention of spontaneous combustion negative.
2) Z-type Backward gob gas is not pouring into the face and flock back to the wind drift. Z-forward style of gob gas then flock to the face, especially on a large corner gas concentrations.
ventilation system is simple and can eliminate the work surface corner of the gas accumulation. The disadvantage is the limited ability of ventilation.
in the face and gob gas emission volume must increase the ventilation tunnel, increasing the ventilation capacity to form a Y-shaped, double-Z-, W-, H-type face and other more complex ventilation system. Y-system in the coal face at both ends of the tunnel are into the wind. Which became a face in the back over the duct, leading to the mining area boundary back up the mountain wind; the case of wing mining area, mining area is adjacent to the back leading up the mountain wind.
3) W-type system for high gas long face or double face. From the middle and lower part of the drift into the wind,"paul smith ties ", the upper drift back to the wind, on the lower face are the MORALS; but the upper wind speed is high,"christian louboutin prive " Can read a car, the dust-adverse; on the corner gas may be overrun. Therefore, a large gas emission, often with the upper and lower drift into the wind, drift back to the middle of the wind; or vice versa, Lane into the air from the middle, upper and lower drift back to the wind, in order to increase air flow, to increase production.
W-type systems face a large U-shaped air flow than double the romantic movement in the face of the short distance, temperature rise is small, will help cool the hot face. W-forward systems roadway maintenance in the mined-out area, air leakage big gob gas emission volume is also large.
W-type back style is fully mechanized coal face of high gas an important form of ventilation.
Third, the anti-wind
mine is a targeted anti-air inlet section of the mine fire disaster of ventilation technology.
normal for the air flow 40%. Mine at least once each quarter should be anti-air facilities, the annual exercise should be carried out in an anti-wind; major changes in the mine ventilation system, should be an anti-air exercise.
Fourth, the basic knowledge of mine ventilation
1. Pressure
keep hot air molecules and earth gravity, the air has the ability to do work outside, or on the wall surface and showing the pressure, that is, air pressure, also known as atmospheric pressure Po
pressure units of Pa,"paul smith purses ", mmH2O, bar, atm
1mmH2O = 9.80665Pa
1bar = 105Pa
1atm = 101324.96Pa
1Pa = 1N/m2
1mmHg = 13.6mmH2O
the air along the underground roadway movement of air pressure difference generated as mine ventilation pressure.
underground air pressure lower than atmospheric pressure is called negative pressure, otherwise known as positive pressure.
(1) Static pressure: the air molecules all the time for the chaotic thermal motion of the wall presented pressure.
static characteristics
a. whether static or flowing air has a static air pressure;
b. romantic in the static pressure at any point to the same value, and perpendicular to the active surface;
c. romantic static size (which can be measured with a meter) to reflect the romantic unit volume has the power to make the static pressure can be outside the number. If that pressure is romantic 101332Pa, refers to romantic 1m3 with 101332J static pressure energy.
(2) digital pressure
objects in Earth's gravity field due to gravity, the location has a different energy called gravitational potential energy, referred to the characteristics of potential energy potential energy

a. potential energy is relative to a datum to which it has energy, it changes along with the selected base-level changes. But the potential energy difference of value.
b. potential energy is a potential energy, it is in the Department of Foreign weak effect, that pressure is not present, it is not as static as a direct measurement with the instrument.
c. potential energy and static pressure can be transformed into each other, to follow when conducting energy into the energy conservation law.
(3) dynamic pressure
When the air flow when the pressure is called dynamic pressure appear that speed or pressure, using symbols hv said unit Pa.

dynamic pressure calculation unit volume of air has the kinetic energy is: Evi = ri × V2 × 0.5
where: ri - I point the air density, Kg/m3;
v- -I point the air velocity, m / s.
dynamic pressure characteristics
a. only for directional flow of air that has the dynamic pressure, so the dynamic pressure has a direction.
b. dynamic pressure is always greater than zero. The role of surface flow direction are exposed to the maximum dynamic pressure (ie, flow direction of the dynamic pressure on the true value); when the role of the angle between the surface and the flow direction, its sense of the dynamic pressure value is less than the true value of dynamic pressure.
c. at the same flow cross-section, due to the uneven distribution of wind speed, wind speed does not equal the points, so the dynamic pressure value range.
d. dynamic pressure is a cross-section of the cross-section average wind speed
(4) total pressure
any point in the airflow duct, the flow direction in its static and dynamic pressure exist, and that both the romantic point of the total pressure, namely: total pressure = static pressure + dynamic pressure.
as absolute and relative static pressure of the points, so the total pressure is also divided into absolute and relative.
A, the absolute total pressure (Pti) Pti = Pi + hvi
B, the relative total pressure (hti) hti = hi + hvi = Pti-Poi
Description: A, relative to the total pressure has positive and negative points;
B, either through positive or negative pressure ventilation, Pti> Pi hti> hi.
(5) tunnel airflow continuity
When the depth is less than 1000m, the romantic little change in density, can be regarded as incompressible fluid.
Q1 = Q2
S1 × V1 = S2 × V2
where Q1, Q2-section 2 of the air flow, m3 / s
S1, S2-sectional area of ​​1, 2, m2
V1, V2-section 2 of the wind speed, m / s
five. Ventilation airflow resistance
When the flow in the roadway, the roadway of the week performance for the block wall of the romantic role, referred to as air resistance.
friction: air flow along the roadway or underground pipe flow, generated due to air viscosity and air friction between the air and roadway within a week of intramural resistance arising from friction.
h where h =
Morocco Morocco - roadway friction, Pa
Q-air flow through the tunnel, m3 / s
- roadway friction coefficient, N • s2/m4
L-tunnel length, m
U-tunnel perimeter (U =, trapezoid = 4.16,
half garden arch = 3.90, three hearts arch = 3.85), m
S-tunnel section area, m2
local resistance
air flowing through the tunnel, some local sites, and the impact of other reasons due to eddy currents caused by the energy loss
3. Drag-reducing measures
①. Expand the roadway cross-section
②. Use a smaller perimeter roadway
③. Reduce roadway length
④. Wind tunnel to avoid excessive
⑤. Cross-section as possible to avoid a sudden increase or reduce the
⑥. Right-angle bend as much as possible to avoid Shui
⑦. Possible to avoid a sudden bifurcation, converging
⑧. Reduce wind speed
⑨.
Two management deposits, ventilation
natural ventilation: the use of air pressure generated by natural conditions, the air flowing in the underground tunnel ventilation.
natural pressure of factors: temperature, depth, density
III. Mine ventilation



1. Series features: large total air resistance, air pollution incident the previous paragraph will be under the influence of romantic.
2. Advantages of parallel ventilation
(1) the total drag in parallel, the total resistance, low power consumption
series parallel comparison
(2) are parallel to the new wind tunnel airflow
(3) occurs if a tunnel accident,"new jordan releases ", the rest of the roadway impact small
(4) parallel the wind tunnel can be adjusted as needed
3. Diagonal roadway romantic unstable and may reverse or no wind
K =
K = 1, BC Lane no wind
K> 1, C → B
K 10m / s)
medium-speed (0.5 ~ 10m / s)
low speed (0.3 ~ 0.5m / s)
Table = n / t
style table - table speed, m / s
n-wind meter readings
t-determined time, s
= A + b
where - true wind speed (after deducting the wind speed error of the table), m / s
a, b-constants
Second, the choice of location
wind wind station
Fourth, wind method
1, sideways method
2, the face of law
average wind speed is calculated by:
= K
type of K-correction factor, sideways law K = ( S-0.4) / S, head-law K = 1.14

five roadway wind
Q = S
Q-roadway where air flow, m3 / s
S-test Wind off site roadway area, m2
- Roadway average wind speed, m / s
six wind wind Notice Table
(1) wind reading errors appear in Table reversed
(2 ) table away from the wind can not too close
(3) wind measured value table even move in order to avoid too large or too small
(4) a cross-section wind of not less than three times, each error is less than 5%
(5) used in the table with the measured wind speed to adapt to
(6) people, vehicles obsolete unexpected
(7) throttle open unexpected
(8) anti-wind when the roof fall, shock
(9) non-wind instruments squeeze
(10) style sheet from the bottom pitch about 200mm, from the state of about 200mm, the first line from the state is not greater than 200mm. Each line that the distance should be uniform.
seven, smoke method
When wind speed is less than 0.1 ~ 0.2m / s when
= KL / t
type of K-correction factor, taking 0.8 ~ 0.9
L-smoke through distance, m
t-smoke through time, s fourth
a roadway air leakage control, air leakage causes
leakage was mainly due to leakage caused by pressure at both ends of region
Second, the leakage of air leakage according to the classification of
mine sites can be divided into external and internal leakage
air leakage in accordance with the nature of the distribution of air leakage can be divided into a continuous distribution of local air leakage and air leakage
Third, measure the leakage of mine Air flow indicator is mine all mine sites independent of the wind with the wind and
Example: A mine the total air volume of 800 m 3 / min, main fan air volume 840 m 3 / min. There are two coal face, each supply air volume 200 m 3 / min; have a spare face, for the air volume 100 m 3 / min; have two heading face, each supply air volume 100 m 3 / min; a mining area and the winch room of a transformer chamber, each air supply of 60 m 3 / min. Which a coal face in series with a heading face ventilation, and the remaining air with the wind sites are independent, non-self-ventilated other locations, calculate the mine air leakage indicators.
Because there is a coal face in series with a heading face ventilation, air volume when calculating the effective mine count only one, choose two of the largest amount of wind, that is, 200 m 3 / min.
Mine Air flow = 200 × 2 +100 +100 +60 × 2
= 720 m 3 / min air flow rate of effective mine
= 720 × 100% / 840
= 85.7%
mine the amount of external air leakage rate
= (840-800) × 100% / 840 = 4.8%
mine the amount of internal leakage rate
= (800-720) × 100% / 840 = 9.5%
Chapter III Section ore mine dust control

a basic knowledge of dust, mineral dust classification
dust: particles less than 1mm in diameter coal particles, coal dust in the general content of less than free sio2 1%.
rock dust: particle diameter less than 5mm of rock particles, dust in the general content of free sio2 less than 1%.
respirable dust: mainly refers to the fine particle size of less than 5μm particles, it can enter the lungs through the area of ​​human upper respiratory tract, leading to the cause of pneumoconiosis.
dust accumulation: the thickness of the underground tunnel there are more than 2mm, the length of more than 5 meters of continuous coal dust.
main tank (heavy) by 400L/m2, auxiliary tank (light) calculated by 200L/m2 water.
tank shed axis perpendicular to the roadway, by the erection of roof lateral, and meet
Second, the mineral dust hazards
1. polluted industrial sites, the introduction of occupational diseases;
2. some of the mineral dust in can explode under certain conditions;
3. speed machine wear and shorten the life of precision instruments.
4. to reduce the visibility of industrial sites and increase the occurrence of accidents.
Second, the and management level, to prevent air, gas, coal and natural ignition accidents, safety management is formulated standardized assessment rating system.
participate in the second evaluation rating must meet the following conditions:
work well for the production of coal in the business, mine ventilation and safety standards must meet the following conditions:
mine must use mechanical ventilation, the installation of two sets of equal ability main fan; mine ventilation ability to meet production requirements, without the ability to produce the phenomenon of super-ventilated.
mine must be conducted annually of carbon dioxide emission levels and gas appraisal.
monitoring system must be equipped with mine, and ensure that the system is operating normally.
1, there are regular ventilation design, ventilation system reasonable and reliable:
2, mine must be mechanical ventilation, install two sets of the same capacity of the main fan and anti-air unit; mine ventilation ability to meet production requirements, without the ability to produce the phenomenon of super-ventilated. Each product has at least two accessible mine ground to the safety of pedestrians exit.
3, the mine must be conducted annually of carbon dioxide emission levels and gas appraisal.
4, must be equipped with mine monitoring system, and ensure that the system is operating normally. Check the contents of the third assessment

l, ventilation systems:
2, local ventilation:
3, gas management:
4, underground blasting management:
5, air safety monitoring:
6, prevention and treatment of coal (rock) and gas (carbon dioxide) to highlight;
7, gas drainage:
8, Prevention of spontaneous combustion;
9, ventilation:
10, comprehensive anti- dust
11, management system.
fourth assessment unit:
well as the basic assessment of the natural unit.
Article inspection and scoring methods, see Table:
1, according to test results, the major items over 90 points and above a mine; 80 points and above for the two mines; 70 points and The above three mines: 60 minutes or more for the four mines.
2, check the large item, check the minimum score of major items of mine rating points.
3, to determine the level of the year: the four-quarter average score rating points classification.
4, to inspect each item missing sub, not excluding the check; check the breakdown of the lack of small items in order to check the breakdown of the item scores of other small percentage of conversion points. Principle points of the item points deducted last.
5,"paul smith designs " 豪情之后呜咽的老是女人, at the same level in order to check the 11 major items in order of average score ranking. Where the gas drainage, the implementation of prevention and treatment of coal (rock) and gas (carbon dioxide) to highlight the measures of the mine, for every a in the above average and then add 2 points ranking.
6, the inspection period, for every Killed three people eligible to cancel the rating.