Christian manz
The PSA Peugeot Citroën Group amazes the automotive world with a hybrid technology that combines a combustion engine with an element that injects air, but in such a way that it can function independently to propel the car. Surprising, right? But not so much if we take a look at the past.
Air, one of the four basic elements of our earth, has always attracted, and continues to attract, inventors as a source of propulsion for a vehicle. The time that the French Guy Negré has been trying to perfect his car powered exclusively by compressed air (an invention that has not yet yielded the desired results), finally makes clear that the idea works best in a hybrid way, that is, combined with other technology.
The Peugeot-Citroën Group has been perfecting its work with air for some time. In the Citroën DS, starting in 1955, high-pressure compressed air was used to drive the suspension, steering, brakes and semi-automatic gearbox. Three years later it was experimented with a Citroën 2 CV hybrid that combined compressed air with a traditional engine that, mainly, gave more and better combustion to gasoline.
This project was surprising, but not enough to develop this technology and direct it to mass production. Today, with all the progress made, it does seem to be an issue to consider.
Land boats
Air is the oldest propellant when it comes to moving something at a certain speed. Already in the China of the fourteenth and fifteenth centuries, the wind was used as a propelling force in vehicles that moved on land. The first of these artifacts with sails appeared in Europe in 1543. The Dutchman Simon Stevin showed that a four-wheeled vehicle could move at quite a speed when there was wind.
The Valencian engineer José Boscasa developed a tricycle with sails in 1802. Its inventor says verbatim:
[su_quote] "Its agent is the air, but failing that it is a handle that is easily handled ... it is comfortable and provides the greatest advantages which are to be able to travel without cavalry safely and promptly ... the air and the handle supplies everything; turns around and contains the alabitrio step of q. it governs it, smoothly and goes up the slopes without difference from any other carriage.
Other engineers tried to perfect the car moved by the wind, using blades of different sizes that transmitted their force to the wheels. The blades were flexible to adapt to the wind without having to depend on where the wind came from. Another idea was to use large kites ...
Compression
The next step was to enclose the air in tanks, compress it and use its force for propulsion. The Englishman Medhurst proposed in 1808 a locomotive coupled to a wagon with compressed air, while the Pinkus patent of 1825 supplied the motor element from a third rail to a locomotive. The Paris-St.Germain (1837) and Paris-Versailles (1844) lines used this type of train. In 1840 the French Antoine Andraud and Tessié du Montay made a powered car with a range of about 10 kilometers.
Compressed air supplied by a third rail was also used in the first trams: in Paris until 1903 thirteen regular lines operated with the system devised by the Polish engineer Mekarski. The next step was to bring compressed air to buses: the first circulated in 1900, completed by Tessier, Lawielle and Molas, with a range of about 30 kilometers. These same inventors also experimented with automobiles.
In favor of oil
When in 1893 the journalist Pierre Giffard published his proposal to organize what turned out to be, in 1894, the first automobile race in the world, the Paris-Rouen, he made it clear that any type of traction would be allowed except that which makes use of animals , which came to be steam, gas, gasoline, electricity ... 102 cars were presented, but only 21 were finally accepted.
There was a clear favoritism towards the gasoline car, which turned out to be the great sensation, which meant that there was no mention of other inventions: among the hundreds of cars that entered there were no less than five vehicles that ran on… compressed air! All of them were disqualified beforehand.
A great media stir was produced in 1899 by the American company Liquid Air, created in Cambridge (Massachusetts) with a capital of 1,5 million dollars to trade with a car powered by liquid air enclosed in a high pressure tank. Expansion of the air, returning to normal pressure, would move the piston of a single cylinder engine. Not much else is known about the company other than that a prototype came into circulation and that it was convinced that it had found the propulsion of the future. In 1901 it went bankrupt.
An alternative Maybach
Compressed air as a driving force continued to attract engineers and inventors. Wilhelm Maybach, the technical creator of the Mercedes automobile, experimented in 1906 with a compressed air engine for which he was granted a patent. This powertrain was not supposed to need a differential, clutch, or brakes. The patent made it clear:
[your_quote]
“A traction for vehicles that consists of a compressed air machine and an explosion machine… The compressed air machine directs its transmission to the rear wheels and can be operated by means of a single lever.
With it the driver opens and closes an exhaust valve located between the compressor and the compressed air motor. If you open the valve, the compressed air is blown out and the resulting friction in the gearbox serves to brake. When closing the valve, the vehicle moves again ... "
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The problems were multiple, the efficiency was terrible, but even so, a test vehicle was built, of which there are still photographs. The machine also exists in the Mercedes-Benz museum in Germany, and it has surely helped other technicians to study its details.
The first Portuguese car, built in 1911 by Alberto Antunes, had a compressed air engine. As the chronicles of the time say, based on an interview with the mechanic, the car needed a small 3 CV gasoline engine for starting and compressing the air; once with compressed air, which moved the pistons, and the car could circulate for a long time without refueling. According to Antunes, it had a force equivalent to 100 CV. Absolutely no noise (except at startup) and no emissions.
Overseas stories
In 1915 the Airmobile appeared in the United States, manufactured by the Rotary Air Brake Company of Los Angeles, declared the safest, simplest and easiest car in the world. It used a frictionless rotary motor, a compressor and compressed air motors; In this way, a four-wheel drive car was born that made it possible to eliminate the crankshaft, camshaft, flywheel, clutch, transmission, differential and brakes. Little else is known about the Airmobile because, like so many other inventions, it has succumbed to oblivion.
In the 20s Lee Barton Williams of Pittsburgh disclosed, without going into detail, that his car ran on compressed air. It started with a little gasoline until it reached 100 km / h, to then change its propulsion to air and be able to reach about XNUMX km / h.
The also American Roy J. Meyers carried out a test with his car in 1931 in Los Angeles; This had four large compressed air tanks in the back, with which it circulated through the city without any cost of fuel and at a practically zero cost. Meyers insisted that the tanks would give it a range of 500 miles (800 kilometers) at a speed of 56 km / h.
In 1933 a bulky bus was presented by WE Boyette of Atlanta that ran on the technology we bring to these pages today. It was an electric-compressed air hybrid. Electric motors were used for starting and to give the air a certain pressure; After a few kilometers, the vehicle was powered by compressed air. A compressor was in charge of filling the air, and a generator of keeping the batteries charged for the electric motors.
An engine for humanity
We have not found witnesses to this type of invention in the years to come. In 1967 the Italian Vittorio Sorgato was presented with an air-powered microcar enclosed in several tanks located under the frame. The little that is known about it is that its speed was about 50 km / h.
In the early seventies the Spanish inventor Enrique Sainz Santosjuanes, who had been perfecting an air motor for years, presented it to the public at the age of 85 saying, as published in the oldest magazine «Velocity», "I present it for anyone who wants to do something with it." We still don't know who picked up the glove ...
The black hand?
At the end of the last century, there were two great surprises. The South Korean company EnerGine Corp., located in Seoul, revealed that it had been working on a car powered by compressed air since 1969, carrying out the first real tests in 1984. Starting in 1992, the company patented its engine in ten countries. In the 1997 tests his vehicle managed to reach 40 km / h; in 2000 it reached 110 km / h, and in 2002 at 130 km / h.
The Koreans combined the compressed air with a battery-powered electric motor-compressor; in 2002 he showed up in Geneva, enthusiastic, ready to go ahead and start serial production of his model that was based on the Daihatsu Matiz. The only thing that was published, months later, was that the CEO of the company had been jailed for fraud.
At the end of 1998 the first data appeared on the project of the French engineer Guy Negré, who had patented an engine that could run on both gasoline and compressed air. In 1999, the first vehicles, with taxi-type bodywork, began to be assembled in Luxembourg, for months later to present the invention in Barcelona.
[your_quote]
“The air motor has two separate cylinders and a small hemispherical chamber. By lowering the piston in the first cylinder, air is drawn in from outside. As the piston rises, this volume is slightly compressed in the small hemispherical chamber. At this time, compressed air is injected into the chamber, which comes from the four cylinders that the vehicle carries, with a total of 300 m3 of compressed air at 300 bar.
The mixture of the air already in the chamber with the high-pressure air produces a significant suppression, since the compressed air tries to expand to regain its initial state. The expansion of this compressed air pushes the piston of the second cylinder downwards and produces the movement and force necessary to animate the vehicle. "
[/ su_quote]
This is how the technicians explained the operation of this engine. A lot has been written about MDIs over many years, and countless adjectives have been used to describe the idea, from revolutionary to fraudulent, from genius to impossible. The company sold factory concessions in many countries, including Spain, where it wanted to install at least eight production plants in different provinces.
High expectations
Guy Negré invited some journalists in 2003 to Barcelona to test the CityCat model (3.84 meters long with a family body, taxi, pick-up or van), and at the same time presented the new MiniCat, which is only 2,65 meters long. Both models made a good impression; However, the few meters that could be covered with the vehicle did not make its supposed autonomy clear. I was present and posted the following notes:
[your_quote]
“Guy Negré told us in November 2003 that there were only a few months to go before series production of his vehicles began in a new plant in Carros, near Nice (France), and then, little by little, production was brought to the first 33 assembly plants in different countries (including Spain).
Another 300 plants would be assembled shortly. In recent years its engine had advanced a lot, it no longer needed the help of a small fuel propellant (first project), nor a system of mixing compressed air with fresh air from the environment (second project).
[/ su_quote]
Now only with its four compressed air cylinders it would reach a range of 200 kilometers and a maximum speed of 110 km / h. The engine developed 25 hp of power and offered a torque of 59 Nm at 200 rpm. The recharge was intended to be carried out in normal service stations, which would have to invest in an industrial compressor that would recharge the cylinders in 3 to 4 minutes at a price of between 2 and 3 euros.
The car's sound was similar to that of a Citroën 2 CV, not very quiet but not unpleasant either; the exhaust pipe was cold and you could not perceive smoke coming out of it. Since they didn't let us see under the hood, The matter was not entirely clear, but the car did not have an electric motor attached. The explanations emphasized that the compressed air engine works the same as a gasoline engine, but instead of fuel, compressed air is injected at 40 bars and less than 25 degrees. Due to the difference in temperature, the air expands and causes the piston to move.
Negré insisted on the success of this mechanic, despite the fact that other experts said that the energy efficiency was insufficient due to physical reasons of the matter. The motor at the same time works as a compressor, but the air can also be compressed by plugging into the home electrical network; a total of 90.000 liters of air are compressed.
The Indian bet
2004 did not finally fire the starting shot. In those years, other engineers had already concluded that the compressed air system for propulsion had to be combined with other systems, and again different versions began to circulate. One of them spoke (in 2006) of an engine that would distribute the four times of an Otto cycle engine to two cylinders: while one would be in charge of compressing the air, working as a compressor, the other would serve for combustion.
In 2007 Guy Negré's MDI company signed a collaboration contract with the giant Indian consortium Tata. A year later, it sold the production licenses for its AirPod model to the Swiss company Catecar, which planned to manufacture more than 40.000 units. According to its president, Henri-Philippe Sambuc, MDI was not able to supply useful technology within two years, so they were forced to withdraw from the project. MDI officials, on the other hand, insist that the company was not sufficiently solvent to pay for the technology.
Anyway, now this Airpod or Tata-Airpod is in the hands of the Indians, which has been announcing for months that the compressed air car is ready for series production. The AirPod now appears to be the Tata of the future. Why is not yet on the street is leaving a lot of speculation and data that are difficult to verify. One of the latest rumors is that the "dark forces" have killed the person responsible for the invention in the Asian house.
And from there we come to the current invention of the Peugeot-Citroën Group, which we will not see in a model of the brand before 2016. The reason why it is not as dark as on other occasions, it is simply a matter of capital available to carry this development to perfection and production. It is one of the reasons why Peugeot has increased its capital with the help of the Chinese company Dongfeng.
In short, Peugeot technology consists of a compressed air accumulator. An air motor compresses air when the car decelerates, and expels it again when the car accelerates. This system reduces consumption, costs little money and is easy to install. It may work only for a few kilometers, but its true function is to assist a conventional engine.
We warn our readers that many information about air cars are found on the Internet, not always true and not well studied. But I am not right in this matter either, we will see in the future if this whole idea was again a dream, as the nuclear car was at the time, or if it is simply “hidden” from us by the great power of the oil lobby.
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