The computing element consisted of six outer surfaces, two of them were planes, two of them were cylinder surface segments, two of them were different helicoidal surfaces.

• 由于榨螺推料面倾角和背面倾角的存在，该计算单元的6个外表面中，有两个平面、有两个圆柱曲面片、还有两个不同的螺旋面。