In chocolate production, stuffing box packing is used for sealing, but this causes high temperatures. The stuffing box packing and shaft therefore wear very quickly, and the maintenance effort is enormous.
CHALLENGE – No need for conventional air barrier seals to prevent sealing gas from entering the chocolate, only small installation space available, use of PFAS-free materials
High product leakages (25kg/d) occurred when mixing grain flour with minerals and stones. In addition, the sealing gas consumption was very high and the seal wore out within a short time.
CHALLENGE – Search for a more efficient sealing solution
Shaft Seal for Screw Compressor
Recompression of Boil off gas
Recompression of boil off gas on LNG tankers can be done by oil-free screw compressors. In terms of economical and ecological reasons leakage should be minimized. Shaft seals for the boundary conditions are available, however not for the limited installation space.
CHALLENGE – sealing of high-pressure difference of two shafts very close to each other.
Depending on the compressor or turbine design, often split shaft seals are required. This means that mechanical dry gas seals are not applicable. When the process gas has to be prevented from leaking, usually oil flushed bushing seals in split design are applied. Such seals require complex auxiliary oil systems to maintain the oil pressure, to cool the flush oil and to clean the flush oil from process gas contaminations.
CHALLENGE – replacement of an oil buffered bushing seal by a gas buffered carbon ring seal in split design.
Typically, titanium or nickel-based alloys like Hastelloy are used when components get in contact with acid gases. Due to competition the price pressure for low pressure blowers is very high. Reducing the cost for the seals while maintaining the same quality is necessary.
CHALLENGE – Sealing of a blower for nitrogen containing hydrochloric, nitric and formic acid.
In respect to rotor dynamics the distance between the two bearings of an axial turbine needs to be as small as possible. Thus, sealings with a short axial length are necessary. Simultaneously the sealing performance needs to be kept high.
CHALLENGE – Sealing of a propane turbine for an organic rankine cycle (ORC) utilizing geothermal energy.
