Cavitation involves the formation of vapor cavities in a liquid. It usually occurs when a liquid is subjected to rapid changes of pressure that cause the formation of cavities where the pressure is relatively low. When subjected to higher pressure, the voids implode and can generate an intense shockwave. This process can be extremely energetic. In many cases this can cause significant damage to rotating machinery such as propellers, impellers and turbine blades. In our case this energy is put to good use.
Our system is designed to continuously harness the energy that is produced when cavitation bubbles are collapsed (crushed). It is based on solid, well understood and accepted physical principles. While it uses some fairly complex elements within its implementation, in principle it is astoundingly simple.
To summarize the process: generate massive amounts of cavitation vapor bubbles and compress them to an infinitesimal size within a very short time frame (milliseconds).
This begs the obvious question. “How do you generate massive amounts of cavitation bubbles and suddenly compress them?”
The answer comes in two parts.
Part 1: We generate the massive quantities of bubbles by injecting liquid water through a specially modified diesel fuel injector. Modern fuel injectors are designed to produce cavitation bubbles in their injection stream. The reason for this is to enhance dispersion of the fuel to improve combustion and hence engine efficiency.
The field of combustion engineering is replete with many scholarly articles detailing the physics of this process. It has been extensively modeled with computer programs. (you can go to fluid-research.com and view animations of this process).
Part 2: We crush the bubbles by impacting the injection stream in a proprietary impact chamber situated very close to the output of the injector. When high velocity water (> 1000 meters/sec) impacts a surface a shock wave is produced and enormous pressures develop within the impacted water droplet. In layman’s terms this is referred to as “water hammer” pressure.
If you open a valve where water is flowing and suddenly shut it off the inertia of the moving fluid causes a water hammer event. Similarly, the physics of this process are very well understood and documented. In our case the water hammer pressure can exceed 50,000 psi. More than enough to crush the cavitation bubbles down to almost nothing.
Now that you have crushed all of these bubbles and released all of this energy how do you harness this energy into something useful?
This answer also comes in two parts.
Part 1: The impact chamber is heated to well above the boiling point of water. Generally, temperatures greater than 400 degrees Fahrenheit. For that matter is can be heated to whatever temperature you want the steam at. The water changes to steam within milliseconds when the crushed cavitation bubbles generate intense heat.
All of the injection fraction is converted to steam. Our injectors typically output anywhere from .175 - .3 ml of water. All of this water is converted to steam. Because the process releases heat the transition from water to vapor does not cool the impact chamber. In actual fact it heats it up, significantly.
Part 2: The water that is converted to steam at the temperature of the impact chamber expands into an individual expansion chamber. A pressure relief valve is set to exhaust the steam when it exceeds the set point pressure of the valve.
The steam which exits the pressure relief valve accumulates in a conduit and is channeled into a prime mover. In our case this can be a reciprocating steam engine, similar to what became obsolete many years ago, or a modern steam turbine or rotary expander.
These devices can be connected to a generator set or anything else that produces useful energy.
You can watch a video of continuous steam production on our individual impact chamber prototype or an early multi chamber prototype. Watch a video of steam generation in action
The provisional patent describes a scalable system. By scalable we mean that groups of these 8 impact chamber assemblies can be ganged together to yield whatever the desired steam in pounds of steam per hour are required by the application. If the requirement is a 1 MW (megawatt) generator or a simple 15 kw (kilowatt generator) it is simly a matter of adding up the pounds of steam required per hour to generate this power (this is how steam is figured in the "world of steam engineering"). The system is comprised of three (3) major elements. These are respectively an impact chamber array, a triplex high pressure pump to feed the injector array and a control computer to manage the entire process.
That’s it. Simple enough, yet very useful in that you have produced this steam without a boiler, on demand and at a fraction of the energy required to produce this steam using conventional Rankine cycle (modified Carnot cycle) heating.