DEVICE FOR MINIMIZING HAZARD OF IGNITION OF GAS MIXTURE WITH USE OF TUNNELING MACHINES OF PARTIAL CUTTING Russian patent published in 2001 - IPC

FIELD: mining; applicable in minimizing hazard of ignition of gas mixtures in operation of tunneling machines with nozzles supplying air and/or water-air mixtures. SUBSTANCE: device has nozzles for throwing of air and/or water-air mixtures. Nozzles are installed on nozzle holder connected with cutting jib. At least some quantity of nozzles in any position of cutting jib covers angle of tunneling machine up to 45 dwg in direction of breast. Nozzles may be installed in nozzle holder for turning. Nozzle holder and/or nozzles may be installed for turning depending on position of turning of jib. Nozzle holder or nozzles may be installed for their separate engagement. Nozzles directed to floor may encompass horizontal zone from both sides of cutting heads over central angle of less than 90 deg as measured in projection on floor. Exit angles in top view on horizontal zones may cover angle of 30 deg inside, and up to 60 deg outside as measured from parallel longitudinal axis of tunneling machine through vertex of these angles. In addition to nozzles directed to floor and horizontally oriented nozzles, nozzles directed upward to breast may be installed with discharge of mixture by these nozzles not less than 33 vol.% of other nozzles. Air may be blown at velocity of more than 75% of sound velocity. Water and air flow rate may be selected within 1: 250-1:2000 l/min. Water is supplied at pressure higher than that of air supply. Velocity of impact of air jet may be set no more 1.0 m/s. EFFECT: reliable prevention of ignition of gas mixture liberating from broken rocks without considerable consumption of cooling water and softening of ground. 10 cl, 6 dwg