Pit climate

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As mine air is known in mining underground, the effect of different climate components to the body of the people . The influencing components are the air temperature, the weather speed and the air humidity .

History

In 1905 Fritz Heise discovered the influence of the relative humidity of the weather on the mine climate. However, considering the individual physical quantities (temperature, humidity, etc.) is not very suitable from a physiological point of view. In 1920 Heise discovered that the increase in the amount of weather , the greatest possible drought and the lowest temperature of the weather, had a positive effect on the improvement of the mine climate. In addition, a cumulative climate measure, called the wet heat level, was defined. When determining the wet heat level, however, only the weather temperature and the air humidity were taken into account, the weather speed was not taken into account. This was not done until the 1920s by the US physiologist Constantin Prodromus Yaglou (1897-1960). Based on research, he defined the effective temperature as a climate measure from all influencing factors.

Basics

The condition of the weather flowing into the mine is changed as the depth increases . The air pressure and the temperature of the weather change. In addition, depending on the local conditions, there is an absorption of water vapor . All of these influencing factors lead to a worsening of the mine climatic conditions. This has a significant impact on the miners' performance . This is because people only feel comfortable in a relatively narrow range of humidity and ambient temperature. This area is called the comfort area in air conditioning. The human body always generates an excess of heat. This excess is greater, the more physical work is done. So that the human organism cannot be endangered by the build-up of heat in the body, the body must release the excess body heat into the environment. This happens through thermal radiation, convective heat transfer, water evaporation from the skin and through breathing .

The climatic factors

One of the main influencing factors on the mine climate is the weather temperature. A distinction is made between the dry temperature and the wet temperature . The dry temperature is influenced by various factors underground. The temperature of the mountains in the mine workings primarily affects the air temperature. The geothermal depth is decisive here . But the conveyed goods (e.g. the hard coal ) also have a higher temperature, which they give off to the ambient air. This then leads to an increase in the weather temperature at the operating points concerned. But machines, the operation of engines, the blasting operation and, ultimately, the heat output by the miners are also heat sources that have an influence on the temperature. High dry temperatures combined with low humidity create a warm, dry climate. In the incoming weather there is already a certain amount of humidity. Depending on the local conditions, the weather also comes into contact with water that escapes from the mountains or is otherwise present in the mine workings. The increased use of wet dust control measures also leads to an increase in the amount of free water in the mine workings. Part of the moisture is now absorbed by the heated air, which leads to an increase in the relative humidity of the weather. By absorbing moisture, the weather cools down. However, the high humidity leads to a warm, humid climate. The dry temperature in connection with the humidity and the weather speed are the determining factors for the effective temperature.

Impact on humans

The climatic factors have different effects on the human body. This is due to the fact that the human body has only limited possibilities for heat regulation, which are strongly influenced by the ambient temperature. The heat given off by radiation to neighboring cooler objects has only a negligible effect. This heat emission is positive up to 33 degrees Celsius, indifferent between 33 and 35 degrees and negative above 35 degrees. The heat dissipation through convection is much more effective. This form of heat dissipation depends on the temperature and the movement of the weather. A very large amount of heat is dissipated by evaporation of the water through the skin, lungs and airways. In particular, the heat dissipation through evaporation of sweat plays a major role. However, this form of heat dissipation depends on the saturation deficiency in the air and the speed of the weather. In a warm, humid climate, the human body can release less heat into the surrounding air by means of evaporation. For this reason, a warm and humid climate is perceived as less bearable than a warm, dry climate.

Countermeasures

Particularly in pits with depths of more than 1000 meters, the effective temperature is so great that, without measures to improve the mine climate, it would assume values ​​of over 32 degrees at certain operating points. At such operating points, the work of the miner is unreasonable. As early as 1905, the General Mining Act was amended to the effect that miners who worked at operating points above 28 degrees were allowed to work a maximum of six hours a day. Attempts are made to reduce the climatic effects through additional breaks, legally regulated permissible employment times and the length of shift times. In German mining, these measures are regulated in the Climate Mining Ordinance. On the basis of this regulation, employment bans can also be issued for certain climatically polluted operating points. But technical measures are also used to cool the weather . In the gold ore mines of South Africa, the weather technology focuses on the heat sources involved in the mine climate . Another measure is the increased cooling of the weather. The weather is cooled down by means of a weather cooling machine.

Individual evidence

  1. ^ A b c Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition. Glückauf Verlag, Essen 1988, ISBN 3-7739-0501-7 .
  2. ↑ Herbert Drost, Thomas Kessler: DSK Mine Saar Schacht Primsmulde - Central refrigeration system. In: Cast iron pipe technology. Volume 42, pp. 72-77.
  3. ↑ a b c Reinhard Wesely: The development of weather technology and explosion protection in the early 20th century up to the mine accident at the Anna II hard coal mine in Alsdorf on October 21, 1930. In: Anna. Sheet No. 23, November 2005, pp. 6-7.
  4. ↑ a b c d e f g h i j k l m n Ernst-Ulrich Reuther: Textbook of mining studies. First volume, 12th edition. VGE Verlag, Essen 2010, ISBN 978-3-86797-076-1 , pp. 61-64, 635-639, 707-710.
  5. ↑ F. Kogelheide: The fight against high weather temperatures by special design of the ventilation and the pit rooms. In: Glückauf, Berg- und Hüttenmännische magazine. Association for Mining Interests in the Oberbergamtsiertel Dortmund (Ed.), No. 41, 63rd year, October 8, 1927, pp. 1489–1497.
  6. ^ A b Commission of the European Communities: Mine gas, mine climate and weather management in the hard coal mining of the European Communities . Information conference from November 4 to 6, 1980, Verlag Glückauf, Essen 1980, pp. 352–353.
  7. ↑ a b c d e B. Stoces, B. Cernik: Combating high pit temperatures. Published by Julius Springer, Berlin 1931, pp. 2–3, 163–164.
  8. ^ A b c d e Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition. Springer Verlag, Berlin / Göttingen / Heidelberg 1961, pp. 622–627.
  9. ↑ a b c d Leo Brandt (Ed.), S. Schimanski: Status and evaluation of research work on temperature and humidity limits in mining work. In: Research reports from the North Rhine-Westphalia Ministry of Economics and Transport. No. 253, Springer Fachmedien, Wiesbaden, pp. 7–8.
  10. ↑ a b c d M. Deiß, V. Döhl, D. Sauer, F. Böhle, N. Altmann: Public measures as conditions of company activities for the humane organization of working life . Research reports from the Ministry of Economics and Transport in North Rhine-Westphalia, HdA project 01 HA 086-AV-TAP 0015, Institute for Social Science Research EV, Munich 1980, pp. 36–37.