Spray Fan Systems.
The spray fan system (nozzles, directional and reverse-flush spray blocks) creates an air flow across the working face, wets the dust and lubricates and cools the picks on the cutting head.

The CDC spray fan system has been well tried and tested and has given excellent service for many years. Its performance has been upgraded with a new design automatic back flush filter and reverse flow nozzles for easy cleaning to ensure that the system remains 100% reliable and effective. II think the word competent is usually applied to a person so I would leave effective in as it refers to a product rather than a person.

The spray fan system, comprising directional spray blocks backed up by a high pressure water system, attacks the coal dust at source - the coalface.”
Setting the Standard for Dust Suppression Technologies in Underground Mining