GEAR FOR HYDRAULIC SEAM FRACTURE Russian patent published in 1994 - IPC

FIELD: extractive industry. SUBSTANCE: cylindrical bottle lowered on pipes is manufactured multichambered. Upper chamber is filled with combustible mixture, medium chamber is filled with solid fuel mixture and lower chamber is full of water. Medium and lower chambers have equal volumes and weakened section is fabricated with longitudinal cut on lower chamber not less than 1.0 mm deep of triangular shape. Its vertex is directed along radius to center of cylindrical bottle. Granulated mixture is composed of ammonium saltpeter and coal in proportion 7: 3 accordingly. Volume of upper chamber should be larger or equal to 0.2 of that of medium chamber. Length of chamber with weakening containing water should be larger or equal to diameter of borehole. EFFECT: improved efficiency of hydraulic seam fracture. 2 dwg