The results of the simulation indicate:compared with cyclone in other domain, the secondary flow of the preheating cyclone with pentagonal inlet and three core volute structure is relatively weaker.

With the condition of the basic hypothesis, the approximate calculation formula was worked out on the gas folwing speed in the tubular centrifugal ventilator.

The reactor pressure vessel composed of spherical top and lower heads, upper and lower flanges, bolts, cylinder and two O-rings, as a static indeterminate system has been studied.