| 摘要 |
842,974. Blowpipe burners. NORTH WESTERN GAS BOARD. April 10, 1957 [March 14, 1956], No. 7948/56. Class 75(1). A blowpipe or the like heating torch comprises a burner head 1 carried by a mixing tube 2 mounted at the outlet of a venturi tube 10 formed in a casting mounted on a recessed block 11 having two bores, the one having a valve 6 in alignment with the venturi tube 10 for feeding thereto through a bushing 4, air under pressure from an air supply inlet 7, the other bore, in communication with a fuel gas source at sub-atmospheric pressure through a valve 12, opening by a bushing 8 into the recess 9 in the block 11 surrounding the entrance to the tube 10 so that the air draws fuel gas from the sub-atmospheric pressure source. |
