To cope with the problem of “the re-entrainment into the hopper of fine dust particles in an inner vortex flow due to the agitation of separated particles" occurring in conventional cyclone separators, some researchers have proposed the adding of a straight pipe at the bottom of the separator, thereby allowing dust-laden air to enter the pipe for further separation.

This paper introduces briefly the manufacture technique and method of penstock s welding, examination and hydrolic test, in view of several major parts of open pipe of the Tianhu hydropower station, such as straight pipe, bifurcated pipe and expansion joint.

Based on the research results of experts,sets out from momentum,and analyses the momentum change of liquid and solids,and puts forward calculation models of settling slurry velocity distribution and friction loss in vertical pipeline.

The computation results show that the effect of density to laminar bottom layer in vertical pipeline is obvious and is bigger than that of viscosity, which can not be ignored.

The correlation of various parameters of soilds on pneumatic coveying in vertical pipeline and the reason of solids choking were presented.

Taking the object of transporting carbon black,analyzed the transportation pressure losing of level pipe、vertical pipe and bend pipe of the pneumatic transportation pipe line,gained the pres-sure losing formula of the three sorts of pipe line.

Hydraulic hoist of solid coarse particles in the vertical pipe is used in oil extraction, chemical engineering, ocean mining, coal mining and silt cleanup and so on.