Patent ID: 9732612
Date: 2017-08-15
CPC Classifications: E21D

Claim:
1. A barrier forming apparatus for forming a barrier between an exposed tunnel face and a tunnel boring machine, the barrier being formed by the application to the tunnel face of a barrier mixture comprising two highly reactive first and second components, said barrier forming apparatus including: a first reservoir for storing the first component; a second reservoir for storing the second component; an applicator having an applicator outlet and an applicator inlet; a mixing chamber having a first port that is in fluid communication with said first reservoir, a second port that is in fluid communication with said second reservoir and a third port that is in fluid communication with said applicator inlet; clearing means that is adapted to expel residue barrier mixture contained in said applicator and said mixing chamber through said applicator, including a third reservoir for storing a clearing fluid, said third reservoir being in fluid communication with said applicator, and supply means for providing a regular flow of the clearing fluid to said applicator, and control means having monitoring means for monitoring the resistance to the flow of the clearing fluid through said applicator outlet, and actuation means for actuating the production of the barrier mixture in said mixing chamber and its subsequent disbursement by said applicator, whereby production of the barrier mixture may occur if there is no resistance to the flow of clearing fluid passing through said applicator outlet or the level of resistance does not exceed a predetermined limit.