Large ladle long nozzle protective casting nitrogen sealing device and manufacturing method

The invention provides a large ladle long nozzle protective casting nitrogen sealing device and a manufacturing method, and belongs to the field of continuous casting. The method comprises the following steps: step 1, assembling a long nozzle heat insulation lining basic mold and a long nozzle outer pipe basic mold; 2, long nozzle blank filling; 3, filling a heat insulation lining material; fourthly, the air outlet channel workpiece is taken out; 5, the cylinder is taken out; 6, covering a rubber cover, sealing, and carrying out compression molding; 7, nitrogen nozzles are arranged in the eight gas outlet channels correspondingly; 8, the long nozzle outer pipe is sleeved with the long nozzle heat insulation inner pipe; ninthly, the annular air chamber uniform workpiece is installed in a gap between the upper portion and the lower portion of the long nozzle inner and outer pipe so that the gap can be conveniently sealed; and 10, sealing the uniform workpiece of the annular air chamber by using a refractory mat