Steam bubble cavitation

Abstract

in Wiley InterScience (www.interscience.wiley.com).Generating hydrodynamic/ acoustic cavitation (Gogate et al.) for a useful purpose encompasses the following energy transformation steps: (1) Burning fuel in boiler. (2) Expanding the steam in a turbine generator. (3) Using electrical output from the generator to: (a) Pump water through a mechanical constriction (hydrodynamic cavitation), or (b) Operate ultrasonic transducer (acoustic cavitation). The combined loss, which is the mathematical product of each of the above step efficiencies, lowers the overall efficiency. An energy efficient method for generating useful cavitation is presented here. It suggests direct injection of steam (I) into sub-cooled water to produce cavitation, thereby eliminating the inefficiencies of the remaining steps (II and III). Cavitation produced by this technique was experimentally and numerically shown to produce collapse conditions similar to hydrodynamic/acoustic cavitation. Direct steam injection cavitation coupled with acoustic cavitation, exhibited 4-16 times greater energy efficiency as compared to acoustic cavitation alone. Similar effects have been numerically speculated for hydrodynamic cavitation.

Flow regime maps and optimization thereby of hydrodynamic cavitation reactors

“…1) and model of Tomita-Shima (for bubble wall Mach no. Mahulkar et al 21 have investigated cavitation induced by injection of steam jet in subcooled water using numerical model for hydrodynamic cavitation. Chatterjee 18 has reported experimental and numerical studies in controlling hydrodynamic cavitation in the shear layer downstream of a sudden expansion.…”

“…Sharma et al 20 have modeled the reactiondiffusion kinetics of a cavitation bubble in flow downstream of an orifice. Mahulkar et al 21 have investigated cavitation induced by injection of steam jet in subcooled water using numerical model for hydrodynamic cavitation. For greater details on literature on hydrodynamic cavitation, we refer to the reader to state-of-the-art reviews by Gogate 22,23 and Gogate and Pandit.…”

Hydrodynamic Cavitation for Food and Water Processing

“…Also, the energy efficiencies for the processes based on the introduction of steam can be much higher as compared to the generation of hydrodynamic cavitation using alterations in the flow and pressure in a fluid ). Mahulkar et al (2008) have shown that direct injection of steam into sub-cooled water can be effectively used to produce cavitation with much higher energy efficiencies as compared to conventional technique of generation of hydrodynamic cavitation. It has also been reported that cavitation produced by this technique was experimentally and numerically shown to produce collapse conditions similar to hydrodynamic cavitation.…”

Electrostatic Force of Repulsion Assists p-p Nuclear Fusion

“…A recent study shows that if a steam bubble is introduced in a cold water pool, due to a fast condensation of the steam from the surface of this bubble a phenomena similar to the cavitational collapse of the bubble occurs. The steam bubble cavitation process was more efficient compared to conventional processes because of the elimination intermediate energyinterchange process [11]. The crystal formation due to cavitation has been attributed to a number of factors such as, 1) local temperature increase, 2) pressure changes leading to rapid cooling rates (10 7 -10 10 k•s -1 ), 3) concomitant shockwaves, which will overcome energy barriers to nucleation and promote crystal nucleation and its growth even at a modest super saturation level [12].…”