• Soft texture: The honeycombstrip is made of nickel-based high-temperature resistant alloy steel, ensuring no rotor damage in the event of rubbing contact.
• Excellent rigidity and high strength: The regular hexagonal honeycombstructure offers superior overall rigidity and strength, providing unmatched advantages over other seal types in high-temperature, high-pressure steam sealing applications.
• Significant moisture removal effect: For blade tip seals in high-humidity environments, drainage grooves are incorporated at the bottom of the honeycombholes to ensure moisture removal, effectively protecting the blades and extending their service life.
• Energy-efficient and high-performance: Years of extensive field practice, experimental testing, and mathematical model analysis demonstrate that under the same clearance and pressure differential, honeycombsteam seals reduce leakage by 50%–70% compared to conventional steam seals. The steam-blocking effect is particularly pronounced under higher pressure differentials.
• Excellentoperational stability: As steam enters the honeycomb holes, the numerous steam-filled holes exert a counteractive suppressing effect on the incoming steam flow. Simultaneously, a concentric sealing air cushion forms around the high-speed rotating shaft, enhancing vibration damping for the shaft and ensuring excellent operational stability of the turbomachinery unit.
• Short retrofit period with rapid results: Retrofitting with honeycombsteam seals requires no modification to the seal carrier or rotor.

Tilting Honeycomb Steam Seal

Based on the standard honeycomb steam seal, this design tilts the honeycomb grid at an angle β toward the air inlet. This technology enhances the sealing performance of the conventional honeycomb seal while introducing new sealing characteristics, making it the most advanced sealing technology in the field to date.

Advantages

Increased damping coefficient: On the inlet side of each individual honeycomb grid, the honeycomb grid is tilted at an angle β. As the airflow passes through the sealing chamber, the air flowing along the inclined sealing surface enhances the kinetic energy of the vortex within the chamber, further increasing the damping against leakage into the next sealing stage. As a result, the sealing effectiveness of each individual honeycomb sealing chamber is significantly improved.

Expanded volume utilization: After the leaking airflow expands and performs work through the throttling gap, it moves into the sealing chamber in a fan-shaped pattern, maximizing the use of the limited volume within the chamber.

Ferrite Floating-Tooth Honeycomb Steam Seal

The ferrite floating-tooth honeycomb steam seal replaces selected high teeth of the seal with ferrite material inlays, and replaces a section of the honeycomb strip with floating ferrite steam seal teeth. The ferrite material used is ferritic stainless steel, which, in its service state, is predominantly ferritic in structure. This type of steel offers several advantageous characteristics, including high thermal conductivity, low coefficient of thermal expansion, excellent oxidation resistance, and outstanding resistance to stress corrosion cracking.

Advantages

Tighter sealing clearance for improved sealing performance: As the ferrite tooth material does not damage the rotor in the event of rubbing contact, the radial clearance between the ferrite teeth and the rotor can be reduced by 0.15–0.25 mm compared to conventional labyrinth seals.

Reducing Type Honeycomb Steam Seal

Through extensive experience in retrofit projects, our company has developed the Reducing Type honeycomb Steam Seal based on the conventional honeycomb steam seal to meet the demands of the power market. Primarily applied to the gland areas of steam turbine units, this seal effectively addresses issues caused by inadequate gland seal performance, such as low-pressure vacuum deterioration and steam leakage from the gland seal.

Advantages

Based on the conventional honeycomb steam seal, a high-temperature resistant composite material inner ring is added. Under the action of springs and limit slots, this inner ring maintains a compensatory seal with the journal at “zero” clearance or a minimal clearance at all times.

On both sides of the inner ring sealing surface are concentric honeycomb strips, which serve to filter the airflow. Therefore, the movement space and sealing performance of the inner ring remain unaffected by steam quality or external contaminants, ensuring reliable sealing performance.

Application Range

Various types of steam turbine shaft end seals, balance piston seals, and diaphragm seals.

Partial Performance of Honeycomb Steam Seal Products