Weather door

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Weather door in the Bochum mining museum
Wooden weather door with horse transport

A weather door is a weather-engineering structure that is used in underground mining and tunneling to regulate the weather draft . The door completely closes a free weather cross-section. Weather doors are manufactured in different designs and from different materials . The execution of weather doors is mandatory.

Basics

In underground mining , it is necessary to provide adequate ventilation for all mine workings . For this purpose, the main flow of weather flowing in through the shaft must be divided and distributed according to the amount of weather required in the individual mine structures. If the weather was left to its own devices , they would find the shortest route to the extending weather shaft . In order to ensure ventilation in all mine workings, the weather flow must be appropriately directed and regulated with weather doors and other weather structures.

construction

Destroyed weather door of the Stolzenbach mine

Weather doors are made from wood in the past or now only from sheet steel , depending on requirements . There were also wooden doors that were covered with sheet iron. The choice of material used has changed over the years. Until the second half of the 20th century, weather doors were usually made of wood, today they are usually made of sheet steel. This is particularly due to the fact that wooden weather doors have serious disadvantages. In addition to their low mechanical strength, wooden weather doors also have a low level of resistance to external influences. Since wood can burn easily, wooden weather doors have little fire safety. For this reason, weather doors made of sheet steel are used in hard coal mining for safety reasons. In the case of main weather doors in particular, which are located in the downweather stream, the weather doors must be constructed in such a way that they are fire-proof . If weather doors are made of wood, the components are manufactured in such a way that the individual wood layers with their fibers cross each other. This construction achieves a good seal in the door cross-section. Weather doors consist of the actual door leaf and a frame surrounding the door leaf. The door frame will be built into the route to the extent of the route expansion . If the route is larger, the weather doors will be built with two leaves.

Door types

A basic distinction is made between two types of weather doors: weather doors that divide the weather flow and weather doors that change the direction of the weather flow. Weather doors that divide the flow of weather usually have an adjustable passage opening. Such weather doors are known as power distribution or throttle doors. Weather doors that guide the flow of weather and influence it in its direction are called power line or barrier doors. Such doors close the entire cross-section of the route .

Throttle doors

Weather doors, which are used as throttle doors, are constructed in such a way that the actual door leaf is installed in a solid frame. In the fixed frame there is a variable opening above the door leaf. This opening is provided with a slide with which the free cross-section can be adjusted as required. The slide has the disadvantage that it can also be changed by unauthorized persons. In consideration of possible accumulations of firedamp , the adjustable opening must be placed as close as possible to the ridge area . In order to increase the partial flow through the throttle door, additional openings must be created in the throttle door. If the weather is even greater, the entire door leaf must be removed.

Barrier doors

Barrier doors must be designed in such a way that they shut off the flow of weather completely. Depending on the requirements, they are installed in a frame made of wood or iron. This frame is sealed at the joints with a wall or other sealing material. To seal the door against the frame or against a second door, the doors are covered with a cloth made of canvas in the area of ​​the hinged door edges. Leather or felt strips are also often attached to the door edge area. In order to be able to achieve the tightness of the door frames over a longer period of time, even with mountains under pressure , the frames are designed in such a way that the masonry partially yields to the pressure through inserted wooden blocks. Another possibility is the installation of sliding frames. A permanent seal cannot be achieved in sections subject to pressure. Weather doors installed there must be reworked at certain intervals. Several weather doors must always be installed one behind the other so that when the weather door is opened there is no unwanted change in direction of the weather train or a weather short circuit . How many doors are arranged one behind the other depends on their importance for the weather distribution and the pressure difference. Several weather doors arranged one behind the other are called a weather lock.

Lineup

Weather doors must be set up so that the weather train can push them shut. The rule here is that the weather door must always open to the incoming weather stream. In mine workings, where a change of the weather direction is possible, two doors opening in different directions are built one behind the other at a certain distance. This ensures that the weather train always presses at least one of the weather doors. So that the weather door closes automatically, either the frame is installed at a slight angle or the door hinges are slightly offset. However, such measures are only effective to a limited extent and have no effect when the door is completely open. In order to close the doors securely, they are fitted with springs or weights and thus automatically closed.

Web links

Commons : Weather door  - collection of pictures, videos and audio files

Individual evidence

  1. ^ A b Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .
  2. ^ Heinrich Veith: German mountain dictionary with evidence. Published by Wilhelm Gottlieb Korn, Breslau 1871.
  3. ↑ a b c d e f Fritz Heise, Fritz Herbst: Textbook of mining studies with a special focus on hard coal mining. First volume, fifth improved edition, published by Julius Springer, Berlin 1923.
  4. ^ A b c d e f g h i Heinrich Otto Buja: Engineering Handbook Mining Technology, Deposits and Extraction Technology. 1st edition, Beuth Verlag GmbH Berlin-Vienna-Zurich, Berlin 2013, ISBN 978-3-410-22618-5 .
  5. ↑ a b c d e Gustav Köhler: Textbook of mining science. 6th improved edition, published by Wilhelm Engelmann, Leipzig 1903.
  6. ↑ a b c d Emil Stöhr: Catechism of Mining Studies. Lehmann & Wentzel bookstore for technology and art, Vienna 1875.
  7. ↑ a b c d e f g h i Carl Hellmut Fritzsche: Textbook of mining science. First volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1961.
  8. ^ A b Ernst-Ulrich Reuther: Textbook of mining science. First volume, 12th edition, VGE Verlag GmbH, Essen 2010, ISBN 978-3-86797-076-1 .