Stainless Steel Lasered Seal for Wet Steam Area of Low Pressure Final Stage Blade Tip, is comprised of neat regular hexahedron small honeycomb cell sealing ribbons on the inner surface of the static sealing ring. It is laser welded of nickel base sheet of the thickness of only 0.05 ~ 0.10 mm on the special molding equipment. The honeycomb belt according to the honeycomb seal ring size is welded to the mother seal body by vacuum brazing furnace through vacuum brazing technology to form the honeycomb seal.
The throttling principle of honeycomb seal is that when the airflow flows through the honeycomb, the vortex is formed under a certain velocity and gap to generate a damping effect.
However, in the actual operation condition, it cannot meet the conditions of vortex formation, and it is difficult to form a good vortex phenomenon.
Its structure is still a rigid seal, once rubbing will cause permanent wear and tear, and the clearance will increase. If the clearance is too small, it is easy to hold the shaft when lifting the machine, resulting in difficulties, and if the clearance is too large, the sealing effect is poor. Therefore, honeycomb is usually used in the wet steam area of low pressure final stage blade tip.
Very low cross coupling
Higher direct damping that labyrinth seals
More forgiving than labyrinth seals in the event of a rotor-stator rub
Variety of materials available to serve a wide range of applications
Capable of sustaining higher temperatures than conventional labyrinth seals
Welding device is three electrodes in the upper part, which carries five welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. There are five welders in every unit area to make sure the strength is enough and uniformly distributed based on electrodes welding of stack and resistance. The honeycomb core generally requires a good precision of welding process, high equipment control on the product and strict quality control during process. Stainless steel honeycomb is mainly for aerospace, high industrial application and civil areas, with the structure comprised of special foils (plates). Instead of general widely used adhesive bonding, stainless steel honeycomb is welded between those joint areas of the hexagonal shapes.
Welded honeycomb seals are an integral part which have to be used on existing aircraft engines and developing engines (turbofan, turboshaft engines and auxiliary power units). For the gas and steam turbines used in the power and oil/gas industries, as well as turbo-compressors should also be supported by this honeycomb seal.