Abstract: Controlled recirculation ventilation technology can be widely used in low-content gas coal mines, and non-coal mines have the characteristic of low-content gas or no gas, which provide anvantages for the widely use of this technology.As long as dust at circulated air is effectively purified, superiority of this technology will be fully brought into play.In using this technology, it is usually considered that pollutants at recirculation working face is generated continuously and purifier is used to reduce dust at such processes as rock drilling, continuous oredrawing and continuous removal in recirculation ventilation system.After researching on the matching relationship between dust size in recirculation system and particle size of high-pressure spray, the layout form with spray head laying against the wind of 45°down, the diameter of spray head of 1.0 mm, the hydraulic pressure of spraying water of 7.5 MPa, and the interval distance of spray head 0.5m can reduce the dust with particle size of 10μm by 90%, which can meet the dust reduction requirements of circulation system.

Key words: Controlled recirculation ventilation system, Dust size, High-pressure spray, Dust reduction efficiency