... the 80%dust,improve working environment. I use: coal injection ,dust-fall,coal preesure reduction,coal-crack,methane drainage,etcII. Function1. moisture enters ... ,releasing some gas,and reducing the gas content in the coal body;2. It can reduce the 80%dust,improve workers ... will expand to come to purpose of hole sealing and coal breaking. 2.The device can be used for several times ...