Automatic sealing system for goaf along gob-side entry retaining

The existing sealing methods for goaf along gob-side entry retaining mainly focus on building sealing walls and sealing wall cracks. The construction period is long and repeated, which consumes a lot of labor costs, has a low degree of automation, and is prone to secondary damage. In order to solve the above problems, an automatic sealing system for goaf along gob-side entry retaining has been designed. The system uses flexible sealing airbags as carriers, placing uninflated airbags between the sealing wall and individual hydraulic pillars in the goaf. The system inflates the airbags to make them in contact with the roof and floor of the goaf and the outer side of the sealing wall in the goaf. The intelligent perception of mine pressure causes deformation of the surrounding rock of the roadway, and the shape of the airbag changes flexibly at any time. That is, when the internal pressure of the airbag rises and exceeds the rated pressure of the safety relief valve, it automatically releases the airbag gas to reduce the volume. The airbag re tightly adheres to the roof and floor surrounding rock. It achieves the effect of continuous sealing of the goaf and suppresses the leakage of dangerous gases in the goaf. The on-site test results show that the safety relief valve opens normally when the internal pressure of the flexible sealing airbag reaches about 4 kPa and stops venting when it reaches about 2.7 kPa. Flexible sealing equipment can sense changes in pressure and shrink its volume to adapt to the shape of surrounding rock, allowing for long-term and sustained sealing of goaf. After the installation of flexible sealing equipment, it has a high degree of adhesion with the sealing wall in the goaf. The volume fraction of gas in front of the sealing wall is reduced by 0.13%, effectively suppressing gas overflow.