The low viscosity of soundless cracking demolition agent (SCDA) slurries makes them difficult to use on rock and concrete breakage in horizontal and up holes, or wet holes. In this paper, self-swelling tablet cartridges are developed by use of additives including adhesive, wetting agent, water absorbent, and activator to SCDA powder through newly developed production technologies. The dosages of adhesive and wetting agent were optimized in the process of powder granulation. Their optimal addition amounts are 3.17% and 11.81%. The self-swelling tablet (SST) experiments and optimization tests show the hardness of SST improved with an increase in pressure and mold filling height. Subsequently, laboratory tests were conducted to determine the influence of the contents of water absorbent and activator on the SST water absorption, reaction temperature, and expansion pressure. The water absorption of SST was found to improve with an increase in water absorbent amount and particle size of the granules. The optimum dosage of the water absorbent is 10%. Based on the laboratory experiments, the optimum amount of additives in the SST is 5% for its best performance. The production of SST cartridges is in a safer and healthier environment compared to SCDA powder cartridges, and its production can be automated to reduce labour cost. Finally, the introduction of SST cartridges expands the scope of application of the SCDA to up holes, horizonal holes, and wet holes.

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For a Francis turbine, when operating at partial flow rate the fixed-pitch runner shows a strong swirl at the runner outlet which induces a helical vortex (so-called vortex rope) in the draft tube. The precessing vortex rope causes severe pressure fluctuation which effects the steady and secure operating of the turbine. Three-dimensional unsteady turbulent flow simulation with RNG k-ε turbulence model of complete flow passage of a model Francis turbine at partial discharge is performed. To verify the simulation, the model turbine is tested on the test rig at the Harbin Electric Machinery Co., Ltd. (HEC), China. An ideal result of the simulation is obtained. The simulation predicts the shape of the helical vortex successfully in the draft tube cone, and the predicted values of the pressure fluctuation frequencies and amplitudes agree well with the test data. The hydraulic disturbance method is introduced, i.e., injecting water with velocity circulation from the runner cone to reduce the pressure fluctuation in Francis turbine draft tube. The injected water with velocity circulation destroys the forming mechanism of vortex rope and eliminates the pressure fluctuation accordingly. The flow in the turbine with water injection is simulated, and it is indicated that with appropriate flow rate and velocity circulation water injection the pressure fluctuation in the draft tube is reduced effectively.