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Ventilators should know that they should be able to -- wind detectors
Release time:
2023-01-06
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Ventilators should know that they should be able to -- wind detectors
1. induction conditions
(1) The wind tester must be qualified through professional training and hold valid certificates.
(2) Master the "Coal Mine Safety Regulations" and the provincial and company methods, processes and precautions for mine wind measurement.And mine air volume, temperature and various gas concentration and other parameters of the provisions.
(3) Master the "Coal Mine Safety Regulations" and the provincial and company air volume distribution of mine ventilation systems and air use locations.situation.
(4) Master the basic parameters of mine wind measurement and the determination of the concentration of methane, carbon dioxide and other gases.Law.
(5) Understand the allowable concentration, over-limit hazards and prevention knowledge of various toxic and harmful gases underground.
(6) to understand the coal mine gas, coal dust explosion and fire prevention knowledge, and familiar with the mine disaster avoidance route.
2. preparation
(1) Check that the air meter switch, zero return device and pointer are flexible and reliable, and the shell and screws in various parts are not loose,The calibration curve of the wind meter is aligned, and the wind meter is within the calibration validity period.
(2) Check that the stopwatch switch and pointer are flexible and the timing is accurate.
(3) Check that the center hole and wall hole of the pitot tube are free from blockage, and the glass tube of the differential pressure gauge is free from damage and scale.Clear, all parts, screws and rubber tubes are complete, all knobs are flexible and reliable, and the liquid injected into the instrument conforms to the requirements.It is required that the mirror and needle tip of the compensated micro-pressure gauge are in good condition.
(4) check the gas detection instrument to complete components, electricity (gas) road smooth, airtight, clear spectrum.
(5) Before entering the well, the wind meter used must be brought according to the task (equipped with a non-conductive meter with a length of about 0.5m), stopwatch, thermometer, gas detector, tape measure, notebook, related instruments, etc.; Carry and useThe instrument must be handled with care to avoid collision.
3. operation method
Selection of (I) Underground Wind Measurement Location
(1) The underground wind measurement location should be selected in the mine wing, horizontal inlet and return air lane, mining area inlet and return air lane;The intake and return air roadways of the mining face; the underground blasting material storage and the main air chamber; and other air needs to be measured.of the location.
(2) The wind measurement in the main air duct shall be carried out in the wind measurement station.
(3) when measuring the wind at the place where there is no wind measuring station, it must be selected in the roadway with regular section, good support, no empty roof,There is no slice, no obstacles in the roadway 10m before and after, no change in roadway section, no turning place, and each measuring point is brokenThe surface must be calibrated regularly (the location with wind station shall be corrected once every quarter; No wind station location, eachThe section of the roadway is measured during the secondary wind measurement; when the wind is measured in the roadway with pipelines, wind cylinders and debris accumulation,Take the net section area of the roadway).
(II) sequence of operations
When the wind is measured at the location of the wind measuring station, the air volume can be measured directly according to the regulations. In the absence of wind stationsWhen measuring the wind at the location, the section of the roadway should be measured accurately first.
(1) Before measuring the wind, hit the wind meter counter and stopwatch pointer to zero.
(2) According to the measured location of the wind speed and roadway section, select the appropriate wind meter and wind measurement method.
(3) When measuring the wind, the air volume of each measuring point shall not be measured less than 3 times.
(4) After wind measurement, timely and accurately convert the measurement data and make records.
(5) After the wind measurement is completed, the concentration of methane and carbon dioxide, atmospheric pressure, temperature and humidity at the measuring point are measured.degrees, etc.
(6) The measured data shall be recorded in the wind measurement record, and the wind measurement board shall be filled in at the same time.
(7) Count all kinds of measuring instruments, and leave the measuring point to enter the next measuring point after confirming that the instruments are complete.189
(8) Fill in the wind measurement report after the well is lifted.
(9) Submission.
(III) measurement method
1. The method of measuring wind position is the sideways method. When measuring the wind by the sideways method, the anemometer shall be backed in the wind measuring section.Stand on the roadway wall, hold the wind meter and straighten your arms in the vertical direction of the wind flow. The blades of the wind meter face the wind flow and are in contact with the wind.The flow is vertical and moves uniformly within the section.In order to eliminate the influence of human body on wind speed, the measured wind speed should be multiplied by the correction coefficient:
k= (s-0.4）/s
(11-1）Where k-correction coefficient;
s -- section area of roadway for wind measurement, m2;
0.4-the area occupied by the wind worker, m2.
2. There are two methods of wind measurement: fixed-point wind measurement and line wind measurement.
(1) When the wind is measured at fixed point, the roadway section is 10 m.2Above 120s; roadway section in 4~10 m2 Measure 60s.
(2) Line wind measurement: the wind meter shall be in accordance with the specified line and time (60s、120s）Move at a constant speed. According to the size of the broken area, the line is divided into four-wire method, six-wire method, circuitous eight-wire method, 12-point method, etc,
(3) According to the wind speed of the measured location, select the appropriate wind meter (micro-speed wind meter 0.3~0.5 m/s, medium speedWind meter 0.5~10 m/s, high-speed wind meter 10 m/s above) for air volume measurement
(4) Return the counter pointer of the wind meter to zero first, wait for the impeller of the wind meter to rotate for about 10~30s, and start the wind at the same time.The meter counter and stopwatch shall be measured and closed at the same time at the end of the measurement. The wind meter shall be opened and stopped with the stopwatch,Stop in unison.
(5) When measuring the wind, the movement of the wind meter on the wind measurement route must be stable and uniform.
(6) The number of air volume measurements at each measured location is not less than 3 times, and the average value is calculated, and the measurement error is notMust be greater than 5%, otherwise it must be measured again.
(7) Record and convert the measurement results in time, and re-measure if problems are found.
(8) When measuring the wind, the concentration of gas and carbon dioxide, atmospheric pressure, temperature, etc. shall be measured at the same time.Fill in the wind test plate in time, and record the original data in the wind test record.
(IV) the air volume of the main ventilator and the main parameters of the mine.
(1) When measuring the wind at the outlet of the main fan, the wind measuring section of the axial fan should be selected at the annular diffuser break.Surface, using the principle of equal area ring to arrange measuring points in the section;At the outlet of the diffuser, the measuring points shall be arranged in the section according to the grid state, and the average value shall be taken after 3~5 measurements.
(2) The effective air volume of the mine is calculated according to the following formula:
Qeffective= ∑Q I^Q dig I^Q adit I^Q Other
(11-2）Where Qeffective-mine effective air volume, m3/min；
^Q I-sum of measured air volume of each coal mining face, m3/min；
^Q dig I-sum of air volume supplied by full air pressure to each heading face, m3/min；
^Q adit I-sum of measured air volume of each independent ventilation chamber, m3/min；
^Q Other-sum of measured air volume at other locations, m3/min。
(3) The effective air flow rate of the mine is calculated according to the following formula:
E=Qeffective/QTotal advance× 100%
(11-3）
Where, E-mine effective air flow rate,%;
Qeffective-mine effective air volume, m3/min；
QTotal advance-total mine air intake, m3/min；
(4) The calculation of the external air leakage of the mine can be carried out according to the following formula:
△Qexternal leakage=∑QMain pass I-∑QTotal return I(11-4）
Where △Qexternal leakage-air leakage outside the mine, m3/min；
∑QMain pass I-Sum of the discharge volume of each main Tongrui machine, m3/min；
∑QTotal return I-sum of air volume of each return shaft, m3/min；
(5) The external air leakage rate of the mine is calculated according to the following formula:
L=∑Qexternal leakage/∑QMain pass I× 100%(11-5）
where L -- air leakage rate outside the mine,%;
∑Qexternal leakage-sum of air leakage outside the mine, m3/min；
∑QMain pass I-sum of exhaust air volume of each main fan, m3/min；
(6) when calculating the effective air volume of the mine and the air leakage volume, the air volume should be converted into the air volume under the standard state, which can be pressedThe following formula is calculated:
QStandard=QMeasurement×ρMeasurement/ 1.2(11-6）
Where QStandard-Air volume under standard condition, m3/min；
QMeasurement-air volume at the measurement site, m3/min；
ΡMeasurement-air density at the measurement location, kg/m3;
1.2-mine air density under standard conditions, kg/m3.
Determination of Working Parameters of (V) Local Ventilator
(1) when measuring with an air meter, first in the roadway 10m in front of the suction outlet of the local ventilator (A-A in fig. 11-2Section) use the wind meter to measure the wind speed, obtain the air volume value; Then in the roadway 5m after the local ventilator (Figure 11-2Section B- B) measure the wind speed with the wind meter to obtain the air volume value; The air volume difference between section a and section B is that of the local ventilatorWorking air volume.
(2) When measuring with pitot tube and differential pressure meter, add a section of air duct to the suction outlet of local ventilator for measuring air section(Figure 11-3), the measurement section is selected at A and B. In order to obtain the average wind speed, the principle of equal area ring can be used to measure the wind speed.6~10 measuring points are arranged in the measuring section. After measuring the velocity and pressure values, the average wind speed is calculated by the following formula:
(11-7）Where VAll-average velocity of section, m/s;
ρ -- Air density at the measuring point, kg/m3;
hvi-Speed pressure value measured at each measuring point, Pa;
n -- the number of measuring points arranged in the same section
The air volume is obtained according to the average wind speed.
(3) When the inlet and outlet of the local ventilator are directly measured with a high-speed wind meter, the hand-held wind meter is close to the protectionThe net is measured by moving evenly within the full section of the suction port for 1min according to the winding method. The wind measurement personnel shall stand on one side,Do not face the suction port directly.
(4) When measuring the air volume of the heading face supplied by the full air pressure, the measuring point must be selected at the suction outlet of the local ventilator.The first 10m air inlet lane is shown in the A- A section in fig. 2.
(5) The air volume measurement of the heading face must be carried out in the roadway 10-20m outside the outlet of the air duct, suchThe C- C section in Figure 2 can also be measured by the C- C section in the air cylinder (Figure 2) using a pitot tube and a differential pressure gauge.(6) The arrangement of measuring points for measuring the air leakage rate of the air cylinder at 100 meters is shown in Figure 3. Pitot tube and differential pressure meter are used first.Measure the air volume of section B and C respectively. The air leakage rate of the air duct at 100 meters is calculated according to the following formula:
P100=（Qf-Q) /(Qf×L)× 100 × 100%(11-8）In the formula, P100-100 m leakage rate of the Swiss cylinder,%;
Qf-working air volume of local fan. m3/min；
Q -- air volume of heading face (amount at the end of the pipe),m3/min；
L -- Length of cylinder, m.
Determination of other parameters of (VI)
1. Pressure measurement
(1) Prepare pressure measuring instruments, tools and materials according to the measurement requirements.
(2) Check the pressure measuring instrument before entering the well. The empty box barometer must be calibrated, and the shell glass is not damaged,The scale and temperature correction table shall be complete, the measuring range shall meet the requirements, and the differential pressure gauge or compensation micro-pressure gauge shall not leak, and shall be installed.There is alcohol, the precision barometer has sufficient power, the value display is stable, the pitot tube is unblocked, and the rubber tube is gas.Good tightness.
(3) Selection of pressure measuring instruments. ① When measuring absolute pressure, use empty box barometer and precision barometer;When measuring relative pressure or differential pressure, use a U-shaped water column meter, a single-tube tilt barometer, and a compensated micromanometer;When measuring the static pressure difference, use a precision barometer; ② When using a precision barometer for measurement, the measuring point must be measured at the same time.Elevation and air density.
Note for pressure measurement:
(1) when measuring pressure with an empty box barometer, place the surface of the instrument box parallel to the wind flow direction and wait for 10 ~20min, while paying attention to the position of the pointer, while tapping the glass of the barometer by hand, until the pointer is stable, directlyRead off the atmospheric pressure at the measuring point.
(2) When using U-shaped differential pressure gauge or U-shaped inclined differential pressure gauge, inject distilled water or alcohol before measuring pressure, UThe liquid level on both sides of the tube is at the same level.
(3) When using a single-tube oblique differential pressure gauge, it is equipped with a pitot tube and a rubber tube, and the nozzle of the pitot tube should be in the right position.Air flow direction; When measuring, first level the instrument, turn the three-way knob to the pressure measurement position, and use a short rubber tube to eliminate the accumulation.The bubbles stored in the instrument, adjust the liquid level of the instrument to zero, determine the correction coefficient K value of the instrument, and thenConnect the "-" end of the upwind side measuring point Pitot tube to the "" end of the load gauge, and the "-" end of the downwind side measuring point Pitot tubeThe end is connected to the "-" end of the pressure gauge. After stabilization, the scale number is read out, and the measured reading is recorded in the record book. At the same timeRecord the calibration coefficient k value of the instrument during measurement, and the reading multiplied by k value is the pressure difference between the two measuring points.
(4) Use a single-tube inclined differential pressure gauge: when measuring, prevent water and debris from blocking the rubber tube, prevent vehicles,Equipment and pedestrians squeeze damaged rubber tubes; All contacts of instruments and rubber tubes should be tight to prevent air leakage from affecting the precision.degrees; be careful when walking with the differential pressure gauge to prevent damage and spillage of alcohol.
(5) When using a precision barometer (also known as a digital barometer) to measure pressure, turn the power switch""Source on" position, turn on the power; set the differential pressure gear to "0" position, and set the selector switch to "battery" position.The value displayed at this time is the voltage of the battery. When the value is less than the specified value, the battery should be replaced or charged.Electricity; After the battery voltage is normal, turn the selector switch to the "air pressure difference" position, and after the instrument is powered on for 15min,can start working.
When measuring absolute pressure, set the differential pressure sub-gear to "0" position, and set the selector switch to "air pressure" position,At this time, the algebraic sum of the number displayed on the instrument and the base marked by the instrument itself is the absolute pressure of the measuring point.(Note: The unsigned before the display number is positive, and the "-" sign is negative).
When measuring static pressure difference, set the differential pressure gear to "0" position, and set the selector switch to "air pressure difference" position,Turn the barometric pressure adjustment knob to make the digital display zero value; then move the instrument to the next measuring point, and the instrument displays the value.That is, the relative static pressure difference between the two measuring points. A positive value indicates that the second point is higher than the first point, a negative value indicates that the second point is lowerin the first point. If only the decimal point is lit on the digital display, it means that the difference exceeds the measuring range of the instrument.The differential pressure gear is rotated to the "" 200 "or"-"200 position, and the actual air pressure difference shall be PAir pressure difference=±200±P ′GasDifferential pressure (P ′Air pressure differenceis the barometric pressure difference shown on the display).
Precautions for using precision barometer:
(1) After the power is turned on, the instrument can work at least 15min later.
(2) When the indication value of the air pressure difference is bounced back and forth by the change of the air pressure, the reading shall be the average within the range of the indication value.Value.
(3) When determining the static pressure of the airflow with a large flow rate, the static pressure pipe should be parallel to the airflow direction as much as possible.
(4) After the instrument is used, the power switch should be turned off and the power supply should be cut off.
(5) If the instrument fails, it should be sent to the repair department for maintenance, and do not replace the components casually.
2. Determination of relative humidity
(1) The relative humidity of air ψ(%) can be measured with a hand-cranked hygrometer or a fan hygrometer.
(2) The two thermometers of the humidity tester shall be in good condition, and the key, gauze, drip pipe and phase checking in the box shall be in good condition.The board for humidity shall be complete.
(3) The hand-cranked hygrometer has two identical thermometers, and gauze moistened with purified water (the wetting procedure is notDripping water is appropriate) wrapped outside the mercury ball of any thermometer;196 Rotate the 120 at a constant speed for 1~2min, and read the readings of the dry and wet thermometers after the value is stable;The reading difference between dry and wet thermometers and the reading of dry thermometers, and the relative humidity ψ is obtained from the relative humidity check table.Value.
(4) Use the fan humidity timer, use the wind to start the fan to form an airflow with an air speed of 2 m/s,After the value of the hygrometer is stable, read the readings of the dry and wet thermometers, and then check the humidity meter to obtain the relative humidity.Degree meat value.
(5) The following items should be paid attention to when operating the hygrometer: ① Personnel cannot breathe into the instrument; ② Must beThermometer numerical change after the stability of the reading; ③ rotating fan hygrometer wind, do not too tight, too strong,to prevent breaking the hairline.
3. Measurement of air density
Use an empty box barometer to measure the atmospheric pressure of the air, and use a hygrometer to measure the dry temperature and relative humidity of the air.The air density is calculated according to the following formula:
Ρ=(0.003458～0.003473）P/T(11-9）In the formula
Old-air density, kg/m3;
P-atmospheric pressure, Pa;
T-absolute air temperature, K;
T-dry thermometer reading, ℃.
4. Temperature measurement
(1) Use a thermometer with a minimum division of 0.5 ℃ and corrected for measurement. When measuring, the thermometerTo leave the human body or other heating body more than 0.5m; To be measured for a period of time after the thermometer readings are stable, recordThe thermometer shall be read and filled in on the plate;
(2) Temperature measurement of tunneling face shall be carried out at 2m of face head-on; Temperature measurement of working facevolume, 15m from the coal wall in the return air lane;The test shall be carried out at the air return port for no less than 8min each time.
4. considerations
(1) The mine shall conduct a comprehensive wind measurement at least once every 10 days. The location, location and cycle of wind measurement shall beThe chief engineer of the mine shall be determined according to the actual situation and must comply with the relevant regulations.
(2) Wind measurement should be carried out at a special wind measurement station. When wind measurement is carried out at a place without a wind measurement station, roadway break should be selected.It is carried out in a straight roadway with regular surface, no empty roof, no obstacles, no water drenching and no turning within 10m before and after.
(3) In the determination of the back air lane of the mining face, the back air lane of the driving face, the air leakage rate of the air duct andThe main inlet and return air volume at the return air side of each chamber shall meet the requirements of wind measurement.
(4) When measuring the wind, avoid the time when pedestrians in the roadway and frequent driving, and avoid the time when the damper switch is frequent nearby.During the wind measurement, no personnel or vehicles shall pass.
(5) When measuring the wind, the dial of the wind meter always faces the side of the wind meter, and the wind meter can clearly see the pointer of the wind meter.Rotate clockwise.
(6) All kinds of wind meters must be equipped with non-conductive meter rods with a length of about 0.5m to measure the wind of large section roadways.Use the meter lever when measured.
(7) When measuring wind, the wind meter should not be too close to the human body and the roof, side and bottom of the roadway, and should be kept above 200mm.Distance.
(8) When measuring the wind in the inclined roadway, the wind meter impeller and the wind flow direction must always be vertical.
(9) In case of locomotives and people passing through or the air door is opened, you must wait for a certain period of time until the air flow is stable.After the wind measurement.
(10) The blades of the wind meter shall not contact with other objects, turn upside down or blow with the mouth. The wind meter shall be put into use after use.The box shall not be handed over to non-wind measurement personnel for management.
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