Stirling Engine

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Welcome to my web site

I was 72 years old when this picture was taken. My life as amateur telescope maker had come to an end, and my life as a retired person had started five years before. The 10 “ telescope in the middel has got a permanent place in my cottage 40 km away on the south coast. Here we can experience a spectacular sight of myriades of stars on a clear, nightly sky in august and september. In Skien where i live , the Milky Way is a seldom sight, due to the disturbance from all light and pollutions from the environment. For me is astronomy still mighty interresting, and the marvellous pictures from space , thanks to the Hubble telescope, still keeps the curiosity and pleasure alive. Links 1. My private life 2. My 42 years in chem. research 3. Machine tools making was my hobby 4. Counting particles from space 5. My way to 180 000 volts 6. Making a Sterling engine ? 7. Antigravity 8. Grandfathers experiment

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My private life I lost my dear Elin in august 1998 I am 83 years old, living alone in my own house, surrounded by a small and beatiful cat. My son Kjell Erik and his wife Ingvil settled in Molde, a city about 600 km north of Skien. They have both their physiotherapy education, now partly working in their trade, partly in school and health department in Molde. My three grandchildren Silje(27) Åsa (24) and Erlend (22 ) are still going through their respective studies at NTNU (Norwegian Technical Naturescientific University) in the city Trondheim.

We keep in good contact by e-mails and phone calls, and I get visits from them as often their jobs and studies allow. Their vacations in the summer time is often used to visit our woderful cottage , laying only 100 meters from the seaside with a magnific view out on the ocean. And it’s only 40 minutes car driving from my home. Take a look :

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Alow me to present my family:

This is my son Kjell Erik Tveten, b 16.febr.1956 After his physiotherapy study in Bergen, he has completed his education with Health Science as Major Subject. He works as independent physioterapeut , and has even a function as Teaching Supervisor at Molde High Scool, Health Division.

This is my daughter–in-law Ingvil Grytli, b 25.des.1956 After her physiotherapi study in Bergen, she works partly as physiotherapeut, partly as People Health Coordinator in Molde. For the time she has started to complete her education. Her final goal is a Master Degree , at the People Health Academy in Gøteborg.

4 This is my grandchild Silje Grytli Tveten, b 19.july 1981 Silje has studiet and worked with Graphic Design, now preparing for a Master Degree in Media, Communication and Information Technology at NTNU in Trondheim. She has been Art Director for UKAO 7, and is active in Trondheims Kvinnelige Studentersangforening.

This is my granschild Åsa Grytli Tveten, b 2.april 1984 Åsa goes through the Sivil Engineer Study at NTNU in Trondheim, Energy and Environment as major subjects. Plans to write a Master Subject concerning Industrial Ecology. She has been avtive in ISFiT and student revy EMIL. Just returned from a years stydy at Instituto Superior Téchnico in Lisboa.

This is my grandchild Erlend Grytli Tveten, b 26.september 1986 Erlend goes through the Sivil Engineer Study at NTNU in Trondheim, for the time Nano Technology. Earlier he studied Physics ans Mathematics, and even Music Technology. He had been very active in The Students Radio, in their program “Unillustrated Science.”

Now time has come to present myself, born 11.october 1925 Concerning my CV, take a look in the next link :

5 42 years contribution in Norsk Hydro’s Resarch Center at Herøya

My 42 years in Norsk Hydro’s Research Center After grammar school in Porsgrunn in 1944, I performed in 1946-47 my militar service in Norwegian Air Force, Comminication School in Oslo. After this, I had three semesters at Stockholms Tekniska Institut, Kemiteknisk Fackavdeling in 1948-49. I made an application for a job at the Resarch Center early in 1950, got an employment and startet my carrier on the 1. april 1950. The first task was a practicability study of the Kroll process for the production of a pure quality of titanium tetrachloride, based on the use of norwegian Ilmenitt as a raw material for production of the intermediate product, liquid titanium tetracloride. Few years earlier the production of magnesium metal had startet. Gradually I was involved in this prosess on the raw-material side, namely dolomit and sea water, where several problems needed better solutions. Step by step I moved forwards in the process link, trying to find the best solutions in the pellet production, where a mixture of fine powdered magnesium oxide was mixed with fine powdwered pit coal, added a magnesium chloride solution, and forming hardening pellet. These were dried and chlorinated, and a molt of liquid (600 ºC ) magnesium chloride could be tapped and lead to electrolyse baths for the produvtion of metallic magnesium. A very tough and contaminating process, creating a lot of environmental problems, with emissions of i.a. mercury and dioxines. A completely new and much cleaner process was under developing at the Research Center, where the Mg raw material was waste magnesium chloride brine from Kali Salz. We developed a cleaning process in a pilot plant, and a prosess for concentrating the purified brine by using a vertical tube stock evaporator. This hot brine at ca. 200 ºC was sprayed, first by nozzles, later in a special constructed sentrifuge. The so called prills were dried in fluid bed,and transportet as waterfree magnesium chloride granules to the electrolysis baths. This so called Brine Process was realized in a quite new plant. After some start up problems the regular production was a fact i 1980, taking over 40 % of our total metal production. The “Brine Process” had great environmental advantages, and initial plans for building a large plant in Canada was evaluated in 1987. The plant was estimeted for a yearly production of 60 000 tons Mg metal, and we began a comprehensive work with estimations, calculations and computations. The Mg-raw material this time was not a brine, but Chinese Magnesitt rock (magnesium carbonate), which had to be dissolved in concentrated hydrochloric acid to achieve a primary brine. For me this involved a lot of pilot plant investigations, including not only the chinese magnesite, but a lot of other imaginable magnesite qualities from other places around the world. The place for the plant became Becancour, close to the St.Lawrence river.

6 Due to several unlycky circumstances, such as a duty protection from USA, and serious budget overrun occured. Nevertheless, the plant got startet and produced magnesium metal as anticipated. Competition with cheap magnseium from numberless of dirty, badly contaminating Chinese “backyard-plants” became a heavy burden for our new and environmentally friendly plant, and it was shut down in 2007. Magnesium production at Herøya had long since been stopped, This happened on 25.october 2001, and about 600 persons lost their jobs. The cause ? Profitability became too low they said, and our general manager Erling Reiten in Norsk Hydro was no longer a popular person for us. On the 29. october 1992 my engagement in Norsk Hydro’s Research Center ended, I was 67 years old, and my retirement was a matter of fact.

The magnesium plant in Becancour

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Machine tools making was my hobby When the house was ready for my familys’s entry in 1966 and we startet a new way of living, the basement stood there, almost empty. A tempting challenge for investments in different kinds of machine tools could be a future goal, but strict economy did not allow for expences of that kind for many years. So what to do ? The answer was of course to build those machines by myself, and so it started. I don’t remember what came first, I guess it was the band saw (1974) but not quite sure. Anyhow, new machines showed up year by year,and possibilities for “fine wood-working” in my little basement workshop increased . Many kinds of furniture for home and cottage in selected woods was performed, to a great satisfaction for my wife, sometimes for my son and of course for my self !

Next machine was possibly the turning lathe for metals , which got a lot more of applacability later when a frequency convertor was installed for precise control of speed.

A thicknesser ( 1985) was the next step , I suppose. This one became a quite irreplaceable

8 machine to get plane surfaces out of sawn wood. And even the deep sound from this machine is like a professional one. I love her !

Next step got the name “long saw” .(1988) It has rolling support, high speed blade, and cuts almost everything, such as coarce planks, all kinds of plastics, thick aluminium an even magnesium. Iron and steel is not recommended, due to high blade speed.

And let me not to forget the appliceable turning lathe for wood (1983) For many years turning of bowls was an engaging hobby, and more than fifty bowls of unlike dimensjons, design and wood type were created her, most of them as gifts for happenings.

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Counting particles from space In “Scientific American”, febr. 2001 Shawn Carlson gave a description for how to build what he called a cosmic ray telescope. By using two home-made, identical Geiger-Müller detectors, and using what is called a coincidence coupling, it was possible to find the direction for particles which had passed both detectors, i.e. a kind of a telescope for ionizing particles. I got a spontaneous interest, this must be tried ! Building two identical detectors caused problems, evacuating and argon filling too, but the necessary high voltage equipment (1500 v) was less problematic. Cosmic particles from above or radiation from small pieces of Uraninit or Thorit was no problem. I had plenty of ionizing particles accessible. But no pulses from my two homr built detectors could be registered, neither directly nor from the coincidence circuit. A long series of homemade tubular GM-tubes were built and tried, but no response. So what to do now ? A good friend loaned me a GM –tube, and I happily observed that my electronic circuits functioned quite OK. I had to resignate, GM tubes must be purchased from some where. On Internet I found that Centronic Ltd. (Radiation Detectors Division) in England had just the type i needed, and from their Mike Bates I got a kindly e-mail , telling me about the complicated procedyres for producing relieable GM-tubes. I immediately ordered two GM-tubes ( ZP 1210), for a total price of Nkr. 2629,-. ( about $ 380,-) The GM-tubes were mounted on a plawood sheet, in a distance about 60 cm. They could be turned around an axis parallell to the axis of the earth. A pulse counter (Velleman building kit) was incorporated, and arrangements for amplifying and letting the coincident pulses from the GM-tubes move the membrane of a small speaker, connected to a ball pen,thus writing a curve on a rotating drum plotter (1 rot. per day). Now everything worked just as expected.

10 A serial of systematic observations started, a timer put inn particle counting 4 min every hour, and so I let it go, day after day. After a scrutiny of all the data I had achieved, I had to realize the following : Any spesific tendenses could not be unfolded ! Variations on direction for incoming coincident particles at moment time had seemingly no effect on particle rate. Particle presence at any time of the day had seemingly no kind of incidental system, in my opinion it all looked arbitrary. Not very uplifting for me ! The explanation turned up gradually: The cosmic proton particles colllides with our atmosphere, creating series of secondary particles. Among these are positive and negativer muons, beeing detectable at ground level. The figure here shows what happens :

The (yellow) muons are what I detected . They come in from unlike directions, giving no identification of incomig cosmic particles direction.

Well, in any case I had a lot of interestingly planning, met new challenges, new knowledge and plenty of funny handwork during this project.

11 I do’nt regret anything, and muons are still my friends.

My way to 180 000 volts

My interest for high tension started when I was 12-14 yars old. I got a coil from an old lorry, looking quite differet from coils today. It had a vibrator for pulsating the battery voltage to the primary coil. From the secondary coils windings came a stream of high voltage pulses, going to the spark plugs in the motor. The voltage could be thousands of volts, quite enough to give very painfull knocks in fingers. This voltage could fill old radio tubes with a mysterious blue light, very facinating to observe in semi-darkness. Later on the interest for radio showed up, but without high tensions, not practicing as an radio amateur with home built transmitter. High tensions showed up again when I on Internet in 1997 found a lot about building “Plasma Globes” by using a “flyback transformer” from a scrapped TV , those who build up the lines on the screen. More fascinating however was what “tesal-saved nerdes” could tell and show about their big and sofisticated tesla generators, produsing high frequent, with sparks in the hundred-thousand volts class. People like Kronjaeger, Jochen and StefanKluge cuntributed with the most, and had a countless suggestions on how to calculate, build and optimize their tesla generators. Warnings and cautions for fatal acccidents was often mentioned. Many people believe that due to the high frequenc the current would only pass the skin of a human beeing, not giving any harm. The truth is not so. The high frequence produced by home made tesla generators will always have a low frequent component due to the use of a so called OBIT-transformer (Oil Burning Ignition Transformer) , giving the wanted “starting voltage “ from the house mains net. The term tesla comes from the hungarian-american inventor Nicola Tesla (1857-1943). He developed the tesla transformer, the transformation of high voltage, 3-phase elctricity over long distances is credited Tesla and a long series of other inventions. He was a genius of his kind, and the all over the world use of 3-phase motors from

12 small to the biggest was his greatest contribution to the electrification of our civilization. Litt.: : The inventions, researches and writings of Nicolai Tesla , Thomas Commerford Martin, 1995.

Diagram for a simple tesla generator.

The OBIT transformer is the “mains xfmr”,nomally delivering 10 000 volts from its secondary coil. Sparks will arise between a circular group of copper tubes. I used 7 tubes with 28 mm outher diam. and 70 mm length.The spacing between tubes are 0.6-0.8 mm. During operation sparks will fill all these gaps, creating problematic heath. The construction with sparks distributed over 40 cm lenght of copper tubes solves this problem. Cap is a high voltage condenser. Different principles for such condensers are possible, but the simples way for home building is to fill common bottles (redwine bottles, 700 ml are very fine) with a sodium chloride solution, putting in a steel rod in the solution and seal the outlet, and gluing aluminium foil to the outer side of the bottle. The capacity for such a condenser will be about 0.8 nF. In my case I coupled 5 bottles in parallell, and measured the total capacity to be 4.2 nF.

13 A very covnvenient design for a primary coil is shown here :

My coil was made of 6.5 mm diam.(¼“) copper tube. For maximum transferred effect from primary to secondary coil it is crucial that frequency for these coils are as close as possible. A calculation of self inductance for the coils I used will be given here : The angle α is

30 º

h= 11.5

cm (4.52”)

W= mean.diam = R+½w = (7.5 + 20/2 = 17.5 cm (6.9”) n = 12 windings Calculated self induction (L) in μH (mikrohenry). Lv = 6.92 x 122 / ( 9x6.9 + 10x 4.52) = 6856 / 107.3 = 63.8 μH Lh = 6.92 x 122 / (8 x 6.9 + 11x 6.9) = 6856 / 131.5 = 52.3 μH L= sqr(( Lv x sin α )2 + ( Lh x cos α )2) = sqr ( 1017.6 + 2051) = 55.4 μH Resonnance freequency for my coil with a 4.2 nF (4200 pF) condenser will be :

f = 103 / 2π sqr ( 55.4 x 4200) = 1000 / 6.28 x 464.6 = 0.343 ): 330 KHz

14 The vertical coil is the secondary in this system. Its self induction was calculated as shown here :

L = h x n2 / 100 ( 10.0 + 0.43) = 7.6 x 9502 / 100 x 10.43 = 6576 μH or 6.58 mH.

The toroid at the top was later eplaced by a closed, 12 liters aluminium pot. The coil has an outher diameter of 7.6 cm, height 76 cm and 950 windings. The ratio between winding height and coil diameter is her 76/7.6 = 10.

The surface area of the coil was calculated as shown here :

Ox = (7.6 x π x 950 x 0.08 x π ) = 5695 cm2.

(wire gauge 0.8 mm diam.)

In practice only half of the vindings surface is estimate as capacity-giving. The area of a sphere with the area (5695/2=) 2847 cm2 has a radius of r= sqr ( 2847/ 4π =) 15 cm. Converted to capacity this will be (15/0.9=) 16.7 pF

Capacity for the big pot : Total outher surface was 3234 cm2, which is eqivvalent to a sphere with a radius : sqr(3234/ 4π =) 16 cm. Converted to capacity this is (16/ 0.9=) 17.8 pF.

Total capacity in the sec. circuit is ( 16.6 + 17.8 =) 34.5 pF A calculation on the resonans frequency in the sec. circuit gives:

f = 103 / 2π sqr ( 6576 x 35.4 ) = 1000 / 6.28 x 482.5 = 0.330 ): 330 KHz So far was my calculated resonans frequency for prim. and sec. circuits exactly the same, giving high hopes for optimal results. Well, I albeit met some trouble. The spark lengt was only 5-6 cm, corresponding to 50-60 000 volts. I felt there was basis for bigger potensial, and planned a more serious investigation. With good advices and support from my good friend Ottar, the following equipment was acquired : • • •

A funcion generator (Voltcraft MXG-9802A , Ebay) PC –scope from Velleman (PCS 64) An old computer (IBM Aptiva, bought in 1994)

The procedure for my measurements was as follows :

15 I made two “ loops” (a single turn isolated wire) , and hang them up around the vertical, secondary coil. The lower one was connected to the function generator, the upper to the PC-scope, which in turn was connected to the computor. Distance between the loops was seemingly not critical. The frequency was gradually endered/increased, and the amplitude I registered on the screen gave a fine view of the signal. When a resonans occured, an increased amplitud could clearly be seen. The resonans frequency i found here was measured to be 328 KHz , in very good harmony to my previous calculations. I got sparks about 16 cm length, i.e. about 160 000 volts. Raising the mains voltage from 230 to 250 volte gave a spark lengt of 18 cm, corresponding to 180 000 volts. And this is how my tesla generator looks like today. Not so very impressive, but I promise you, the spark is highly dangerous to touch. It spark has a sharp, hissing sound, and the smoke detector is affected, making additional noise in my basement. Perhaps it should be funny to enlarge to higher tensions and getting more “show” out of it, but my basement headrom is only 210 cm. No place for such adventures for me. Tesla-nerds in USA use big garages and halls to try out their large vonders, and find it very amusing taking pictures beeing in the midst of their impressive sparks . But such pictures are of course double-exposured !

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Making a Stirling Engine The Stirling engine is a heat engine whose heat-excange process allows for near ideal efficency in conversion of heat into mechanical movement Robert Stirling ( 1790-1878) was the inventor. At the end of the 20th century there were worldwide about 250 000 Sterling engines in use. Today, with with growing ecological conscience and ever-rising fuel costs, the undemanding and quiet Stirking engine is attracting renewed interest.

- and the Stirling motor principle is quite simple ,isn’ it ? I found lot of detailed descriptions about practical solutions were found on Internet, also showing a great diversity of constructions. Juste take look below : The most simple and funny version is perhaps the “Coffe-cup” : The amateur built version looks often something like this :

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and a proffesional one could looks like this

Stirling engine and generator set with 55 kW electrical output, for combined heat and power applications. What a challenge for me ! This had to be tried, no doubt about it ! The simplest version was nothing for me. A more advanced one could be the best choise, and I started my planning. I will not bother you with all details and the problems i met on my way. There was plenty of them in my construction, but gradually the engine got its ultimate form, and time was ready for a startup. But sorry, I never succeded getting my engine to function,whatever I tried to adjust and regulate. But believe me, I was very,very close up to a success. The engine made 3-4 strokes, so it “died”, time and again . What was the reason for my blunder? Probably a little too small diameters to overcome the frictions between sealing devices in my elegant construction. When piston-cylinder diameter increases with a factor of 2, the steam-exposed area on pistons will increase with a factor of 4 , and so also necessary force to overcome friction due to sealing devices. The contact surface between piston and cylinder will only increase with a factor of 2, letting forces for moving pistons up and down to increase with a factor of 2. Totally this means a doubling of forces to overcome the friction. Hope I’m right !

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Antigravity I guess everybody has felt some fascination looking at a spinning, humming top, quite unaffected rotating in its own way, seemingly having it’s own meaning of how to behave when you try to affect it’s stubborn behavier. In a physics book you could find an explanation for this phenomena like this : “When trying to affect the spinning, the axis of a gyroscope will make a movement perpendicular to the moment , trying to get it’s own spinning axis parallell to the moment “ This cleared up everything, didn’t it ? The gyroeffect comes into our lives in a lot of occations. When bicycling it allows you to drop the handbars and still keep the balance, provided the speed is suficcient. Apropos the bicycle, a wheel of this is the best to use for getting feelings of the sinister forces in gyroeffect. If you mount a handle at the outstanding axis on one side, takes a god grip and put the wheel in quick rotation with your arm outstretched, curious things happen. If you turn around your own axis, one of two things happen : Either will your arm be drawn down, or it will be liftet up. Which way depends of the direction you turn around. When i obeserved this phenomena, I got an ingeious idé : Give me two such wheels, one for each arm, and let me turn around my own axis, both arms outstanding. Either I will feeel a lift of my body, or feel my body beeing pressed down, dependent on the way of rotation. Standing on a short, motor rotated bench with a steady foothold, and correct turning direction for wheels and myself, I should feel a lifting force upon my body ! And what if I let a rack take over my place, and put in three motors for wheels and rack rotation ? Could such a system rise from the floor ? Yes. it had to, no question ! This impossible trick, lifting oneself up in the hair was within rich, and the physical laws for gravity had to be justified. The feeling of this possibility gave me a feeling of both delight and freight. What to do next ? Shortly after i read in New Scientist 20. oct. 1990 under the section Review, with the title : Gyroscopes remain the strangest of attractors, and a newly published book Beyond 2001, The law of physics revolutionized, written by an englishman, Sandy Kidd. immediately ordered this book, waiting impatient for the book to come. With shivering hands i opened it and started reading. Kidd describes how he got his idea, building a machine to develop gravity forces, able to lift itself up in the air. His book had no drawings or pictures of his invention. The only thing to observe was on the cover of this book, shown here.

19 His principle was seemingly exactly the same as I had in my thoughts, namely two quick rotating flywheels, spinning around a common, vertical axis. Kidds machine had a height of about 30 cm (one foot), and had a small gasoline motor. In the first part of his book he gives a description of what happened in his garage when he for the first time should start up his machine. He had locked the door, wished his wife good night, and she said to him : “You’ve nothing to loose, Go on”. His machine was hanged upp with spanners as balancing counterweights, and Kidd started the motor. The rotational speed could be regulated by the trottle, and the max.speed was about 9000 rpm. He increased the speed, step by step. What Kidd now experienced gave him a creepy feeling : His machine suddenly startet to arise to a certain level with a wail, fully challenging gravity. Kidd loosened spans, one by one, unil he had removed about 250 g (8 ounches) Then his machine started to lower. Kidds efforts to getting help for explanation and further development is well described in his book, but no person, even highly qualified in physics could give him any satisfactory explanation of his adventure. The interest for realizating my own idea was further strengtened, but in quite a different way than Kidd did. My two bicycle wheels was of course used, beeing turned around by identical sewing- machine motors. A third, some stronger motor turned the whole system around. Speed of motors could to some extent be regulated. And my big “clue” was : The machinery rested on three bathroom scales ! Would I get a glimpse into the mysterious gyroscopic heaven like Kidd, or would it all go down to the dogs ? I’ll tell you this now : I startet the wheels, got them spinning with moderate shaking. Lifting forces were still lying in wait. So motor C was gently started, continiously viewing my bathroom scales. The machinery began shaking, and the reading on scales became more and more blurred. The vertical axis speed increased, and gradually I felt that a formidable crasch might occur at any moment. The scales was impossible to read off, due to the vibrations. Of cours I colud let the whole ting go on to the bitter end, and experienced a horrible and complete crash, but instead I resignated and stopped the show. Later on I have done some philosophy around these events. For the first:

• • •

Had Kidd in his garage really observed what he describes ? Was it only free fantasy, or somerhing he only believed happened ? If he told the truth, why could’nt he later reproduce his experiment

20 I find no reason to doubt when he tells about qualified persons tatements, that no one were able to disprove his observations. Kidd wrote about it : “ the device gave a final, excrutiating howl and glided upwards until it howered three inches above the worktop” He writed later the following : “perhaps it had someting with harmonic resonans in the system to do “. Perhaps Kidd’s machine operated in a border land of physics when his machine suddenly rised. At least two things lacks:

• •

A physical/matematic theori that could calculate necessary speed and material strength that appears. The choise of right materials, shape /construction .

My little philosophy : Only a spinning giro can show us the right way to go, regardless to its surroundings. . They never mistakes in their strange cooperation with inner structure of the universe, because their forces are part of it. Did you ask what happened to my machine ? Sorry, it was disassambled, and no pictures were taken. Probably I felt a kind of shame. A picture of the sawing motors on the light-metal construction was however taken . Take a look :

With my best regards

Kjell W. Tveten