Ventilation critical to DUNE success

The Oro Hondo shaft exhaust fan is essential to controlling airflow underground. Photo: Matt Kapust, SURF

From Deep Thoughts, January 17, 2017.

Air flows down the Yates and Ross shafts and is pulled through specific areas underground by two air shafts: Number 5 Shaft and the Oro Hondo. With the Deep Underground Neutrino Experiment (DUNE) just on the horizon, the reliability of the Oro Hondo ventilation system, in particular, is critical.

A direct drive, variable-frequency fan powered by a 3000 horsepower synchronous motor (it currently draws less than 400 hp), the Oro Hondo was built in 1986. Since then, it has undergone repairs and had parts replaced as needed and, in 2010, underwent a significant rebuild as Sanford Lab prepared to install the first physics experiments on the 4850 Level.

Deterioration of the shaft can inhibit airflow, so it was critical to understand the integrity of the wall rock, said Bryce Pietzyk, underground access director. However, because there is no conveyance in the shaft, Pietzyk turned to experts to find a way to get “eyes on” the rock from the surface to the current muck pile elevation. A special scanning method, developed by Professional Mapping Services, Firmatek and Mine Vision Systems, was lowered into the shaft to collect data on ground conditions.

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