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Sendzimir Split Housing Mill Design

While Sendzimir has long championed the monoblock housing mill design because its inherent strength and stiffness make it unlike any other mill housing in the world, the Sendzimir split housing mill design offers several benefits as well! This design is especially convenient for wider strip widths and for Silicon Steel Rolling.

Mill Stiffness

One beneficial aspect of the split housing mill design is that the stiffness of the mill housing, or Mill Modules (metric tons per millimeter stretch), is comparable to our monoblock housing. The stiffer the mill is, the tighter the gauge tolerance is, and the flatter the strip shape is. Thus, it is easier for the mill operators to control both parameters during the rolling process.

While our Monoblock housing has the strongest mill modules for a ZR 21 mill, at 496 MTons/mm, the Sendzimir split housing design is the second stiffest at 320 MTons/mm, which makes it an ideal choice for projects that require a combination of strength and wider strip widths.

Our split housing design is unique in the industry because the two housing halves are pre-stressed together prior to rolling to a number higher than the maximum RSF (Roll Separating Force). Thus, the housing appears to be a monoblock housing for all practical purposes. The mill housing can be opened for roll change and for clearing strip wrecks, or for any other reason. In addition, housing spacers can be placed between the two halves so that a slightly larger work roll can be implemented. Lastly, load cells can be placed between the housing halves so that an actual RSF can be calculated.

Sendzimir Avoids Common Split Housing Mill Missteps

In more recent years, various competitors have attempted to similarly offer customers the idea of a split housing mill in a 4-High housing. In theory, this idea would be incredibly convenient, as the split housing could be easily separated vertically for clearing strip wrecks using the upper or lower screwdown cylinders. Unfortunately, this split housing in a 4-High housing design has a very low overall mill modulus, and subsequently loses the major advantages of the Sendzimir design. The resulting design is unnecessarily complicated, and therefore, more prone to maintenance issues over time. Sendzimir avoids these complications and instead focuses our energies on producing simpler, more streamlined designs that maximize mill strength.