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Measurements of Velocity Profile in Headings with the Use of Integrated Hot-Wire... |
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Measurements of Velocity Profile in Headings with the Use of Integrated Hot-Wire Anemometric System Authors: P. Ligęza, E. Poleszczyk, P. Skotnicz
In this paper we have presented a hot-wire anemometric system constructed in Strata Mechanics
Research Institute, Polish Academy of Sciences, which was applied in practice to measure velocity profi le
in a selected cut of heading.
Hot-wire anemometric system for multi-point measurements of velocity fi eld is based on sensors
integrated with a signal conversion module. A Sensor matrix, so-called integrated heads, is connected
to a mobile measurement data collection system and placed in a given cut of a heading. Arrangement of
measuring probes in selected velocity fi elds and subsequent registration and conversion of signals from
given probes allow for a simultaneous measurement of temperature and velocity fi eld, turbulence intensity
and also for determination of volume stream.
Performed measurements had as an objective to evaluate metrological suitability of the measurement
system based on hot-wire anemometric integrated probes, in which a measuring element consists of miniature
platinum-ceramic sensors in specifi c conditions of heading. Hot-wire anemometric system was
used for measurement of distribution of air fl ow velocity module in a selected cut of a heading.
Measurements were performed in a cut of a cross heading 713, “Borynia” coal mine. Cross heading
was a major heading with a cut of 14 m2 – cross cut dimensions were 5 × 2.5 m. Four hot-wire anemometric
sensors placed on a special extension arm were used for measurement of instantaneous distribution
of velocity module .
Despite some discrepancies with literature sources results described in this paper confi rm that used
hot-wire anemometric measurement system allows for measurements within logarithmic substrata of
velocity distribution of stringing layer, which consequently allows for further assessment of local fl ow
phenomena in headings. In assessment of properties and metrological usefulness of applied hot-wire
anemometric system of integrated heads it must be emphasized that despite 90 minute long measurement
and data registration the system worked smoothly.
There may be certain conclusions on practical improvements of the system, however elements
used in the heads, which measure velocity are characterized with high mechanical resistance in special
conditions.
Keywords: hea |
2011