Whirlwind

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A vortex duct is a special duct for mixing the air ( weather ) in mining . It is used in blind-ended tunnels (sections of the route) and similar places that are difficult to ventilate and that require special ventilation . In addition, vortex tubes prevent the formation of methane layers. Due to the Coanda effect used in these ducts , the ducts are also called 'Coanda vortex ducts'.

Basics

Methane can accumulate in certain areas with poor weather conditions, especially in the area of ​​the face , in specially weathered routes . Additional measures are often necessary in order to mix the mine gas escaping from the face, the ridges or the heaps with the weather. In addition to so-called air movers and flat jet nozzles, vortex pipes are also used to mix the weather.

Construction and installation

Vortex pipes (Coanda vortex pipes) consist of two to five meter long elements and are constructed in such a way that the axial weather outlet opening is closed. Instead, this vortex duct has special outlet slots that are arranged radially to the axis of the line. Due to the design and size of the slots, the amount of locally escaping weather can be freely selected. The weather escaping through these slits has high speeds and can thus prevent the formation of methane layers in the ridge area. In tunnel construction , the vortex pipe is used to dilute the dust locally. It is also used to ventilate the machine area during machine tunneling . The vortex duct is laid at the end of the duct at a certain distance from the face. The distance is determined using a special formula.

Individual evidence

  1. ↑ a b c d Walter Bischoff , Heinz Bramann: The small mining dictionary. 7th, revised and expanded edition. Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7 .
  2. ↑ a b c d Ernst-Ulrich Reuther: Textbook of mining science. First volume, 12th edition, VGE Verlag GmbH, Essen 2010, ISBN 978-3-86797-076-1 , pp. 605, 617–618, 696–697.

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