Rigid Seals Research Articles

Designing on Magnetic Seal Ash-Unloader without Abrasion

The rigid seals currently being used for the ash unloading device with the impeller under the hopper of the electrostatic precipitator are easy targets of wear and tear. In addition, the airproof capability of these seals is not perfect. In this light, an advanced powder magnetic seal design which installs permanent magnets at the top of the vane and utilizes the magnetism of Fe3O4 in fly ash to seal the space between two vanes is discussed in this paper. In the self-designed device, three categories of permanent magnet parameters and four kinds of powders with respective with respective magnetic powder mass fractions of 7%, 9%, 12%, and 15% were chosen. The airproof capability was also measured. The results show that this device has excellent airproof capability, can withstand wear and tear, and has a low replacement frequency.

A review of sealing technologies applicable to solid oxide electrolysis cells

This article reviews designs and materials investigated for various seals in high temperature solid oxide fuel cell “stacks” and how they might be implemented in solid oxide electrolysis cells that decompose steam into hydrogen and oxygen. Materials include metals, glasses, glass–ceramics, cements, and composites. Sealing designs include rigid seals, compressive seals, and compliant seals.

Verschleiß selbsttätiger Pumpenventile durch abrasive Suspensionen

AbstractWear of automatic pump valves by abrasive suspensions. In pumping of abrasive suspensions with reciprocating displacement pumps against high pressures, the pump valves prove to be subject to serious wear. Wear of the piston seal can usually be avoided by washing or by separating membranes. Pump valves are fitted with elastic or rigid seals. To resist corrosion and temperature effects, frequently the only possible approach is to finish them in metallic or carbide materials. The major kinds of wear are demonstrated by a tribological study. The rates of wear found for a real valve model with a high pressure experimental setup depend upon the pressure and frequency of reciprocation. A hardness‐dependent region of instability exists where wear scoring arises. The volume wear rate for various arrangements of materials and abrasive particles exhibits a crest/trough nature. A design strategy and construction aspects are considered and compared with practical experience.

Behavior of Hydrostatic and Hydrodynamic Noncontacting Face Seals

In this paper, the pressure generation and static stability of face-type seals are discussed and an expression is developed to estimate the effectiveness of hydrodynamic action in these seals. Some design data are presented for the hydrostatic step seal, hydrostatic-orifice compensated seal, hybrid spiral-groove seal, and the shrouded Rayleigh step seal. These data are applicable to large-diameter seals for compressible fluids. The seal ring distortions due to initial imperfection, pressure, and thermal expansion are discussed. Approaches to estimate and to minimize the effects of these distortions are outlined. Finally, the ability of a face seal to track the vibrations of the runner is also discussed and methods required to determine the dynamic tracking for rigid or flexible seals are described.