Proof of Concept
All the assertions made above rest on the simple fact that hot air rises and that convection currents can be harnessed to do work. No experimental work has been carried out and there is no direct research evidence to justify the claims made. There are however a wide range of examples that demonstrate that the theoretical principles described are valid.
When one looks up convection or convection currents in physics text books, there is very little information. Yet this is what drives the water cycle, causes sea breezes and land breezes, creates winds and climate. Nevertheless in physics, convection currents barely rate a mention.
Despite their overwhelming importance in nature, there is not a single industrial example I could find of the application of convection currents. They are important in cooling but there is no industrial process that attempts to harness the energy of convection currents. The nearest example perhaps is hot air balloons, where heat is used to raise a payload.
But we have thousands of years of experience of wood burning and the domestic coal fire. The combustion products are lighter than air and rise up the chimney drawing in fresh cold air which is heavier at the base. There is no example however of trying to harness the energy of the rising hot gases for mechanical energy or to make electricity.
There are however many examples of the use of thermal currents. The sport of gliding depends on strong thermal currents – it is well known that power stations provide wonderful thermals!! Many birds of prey and migrating birds that travel prolific distances seek out and depend on thermal currents. A rather bizarre but outstanding example of the use of thermals is by vultures in Tibet. It is custom not to bury the dead but to take the human body to the mountains to be devoured by vultures. They consume every part of the body but the large bones and skull present a problem. Vultures have learnt that in the morning there are strong thermal currents. A vulture will lift the skull in its talons, use its wings and thermals to acquire a great height and then lets go of the skull. As it crashes onto the rocks, it splits open giving the bird its food.
In the world’s oceans, convection currents are critically important. There are certain regions known as upwelling areas where volcanic activity on the ocean floor causes warm water rich in nutrients to rise to the surface. Upwelling areas are biologically prolific. Likewise arctic waters are very cold allowing warm waters beneath to rise. Because they are rich in nutrients, arctic waters are very fertile.
The above examples show that convection currents are extremely important in nature in the interface between biology/geography and physics. But what about combustion itself, is there any example of the importance of convection currents?
The firestorm that followed the intensive bombing of Dresden provides an outstanding example of the power of convection currents. The bombing caused hundreds of fires throughout the city – the hot combustion gases rising, drew in fresh air with winds of up to 100 mph creating a firestorm. There was a similar firestorm after the bombing of Hiroshima.
On a visit to the National Palace in Sintra, Portugal in 1994, I was extremely impressed by the tall chimneys. They must be the largest in Europe and the kitchen is of unique construction to deliver a large volume of cooked food. It is simply the principles of the domestic coal fire magnified 1,000 fold but I wondered immediately, why can’t we harness the energy in the rising hot gases inside the 100 ft high conical chimneys? The Pantheon in Rome is likewise a massively impressive simple structure.
As one enters the double door there is a strong draught of air coming in from the outside. It is because human activity inside the building and the very presence of 100-200 people generates heat. The warm air rises through the circular hole at its apex drawing in cold air at ground level.
The most outstanding proof of concept that I have found for the above ideas comes from a children's Science Encyclopaedia. Under the heading ‘Turbine’ which describes the operation of industrial turbines, is the illustration below:
This describes precisely the principles of the convector generator. The burning candles produce hot combustion products which rise. The current of hot gases can then rotate a turbine and go on to produce electricity. The demonstration is reminiscent of the lower school science experiment of cutting out a paper spiral, hanging it on a thread some distance above a burning candle to demonstrate the existence of convection currents. The above illustration proves that hot gases can produce rotation – it is then only a question of containment, changing the scale and improving efficiency.
The solar drier used in some developing countries gives another illustration of the principles of the convector generator. Warm air rises drawing in fresh air at the bottom of the drier – this is heated as it passes through the simple ‘solar panel’. The warm air then dries the rice grains. Such natural convection currents are precisely those described earlier in the sections on solar energy and roof solar electricity.
A further example is rotating vents sometimes placed over chimneys. They are to stop rain or nesting birds. As the flue gases pass through they cause vigorous rotation. This is the principle of heat energy producing rotation which could in turn generate electricity.
All the above examples illustrate the existence, nature and importance of convection currents. They confirm the principles adopted in devising the convector generator and its range of applications. No experimental work whatever has been undertaken and no patent application will be made or sought. The above summary is drawn from 500 pages of handwritten notes compiled from 1987 which will be made available in due course.
Dr Alan Williams
E-mail address: williams.a(AT)globalwarmingsolutions.co.uk