Thermo-Electric Generators

Thermo-Electric Generators

Left: The Clamond Thermopile: plan view.

The solid sectors A were made of the alloy, while the cooling fins F were made of sheet iron to act as cooling fins for the cold junctions.

From "Electricity in The Service of Man", a much longer book than "Electricity in The Service of Chameleons"

Left: The Clamond Thermopile: reality.

Note gas feed with tap running into the centre of the pile.

This example is in the History Museum of the University of Pavia in Lombardy, Italy.

Left: The Clamond Thermopile: section.

Showing the multiple annular burners in the centre of the pile. Gas enters through tube T.

According to the French journal La Nature for 1874, one of these piles was in use at the printing works of the Banque de France, presumably for electroplating.

Picture from La Nature 1874.

Left: The Improved Clamond Thermopile: 1879

The EMF of this pile was no less than 109 Volts, with an internal resistance of 15.5 Ohms. The maximum power output was therefore 192 Watts, at 54 Volts and 3.5 Amps.

This pile was fired by coke. The hot junctions were at C, while the cold junctions D were cooled by sheet iron as in the original design above. What purpose was served by the tortuous path T-O-P taken by the hot gases is unclear, because there seem to have been no hot junctions in the inner sections. This beast was 98 inches high and 39 inches in diameter. It was a very serious piece of machinery, quite capable of delivering a lethal voltage.

The second version of the Clamond and Mure pile used the alloy of Marcus (Zn 66.6% and Sb 33.3%) for the negative material, and iron for the positive material. It surpassed all other similar piles and won the Gold Award of French National Industry. In 1876, the "Thermo-Electric Generator Company" (France) began the mass production of Clamond's thermopiles. But soon it turned out that generators had serious problems: the thermocouples melted, oxidized rapidly, and exfoliatied. This affected the pile's efficiency...

Clamond needed four years to develop new thermoelectric materials and improve the construction of the vulnerable elements. His new "Clamond Improved Thermopile" was based on the alloy of bismuth and antimony (negative material) and on iron (positive material). This efficient and powerful generator was 'free of all imperfections of its prototypes' and was the considered the best pile of that time.

On May 1879, the new Clamond's generator was presented to the French Academy of Sciences.

From "Electricity in The Service of Man" Further details come from Rankin Kennedy. The pile shown here was described by Clamond before the Paris Academy in 1879. It had 3000 elements, and at 20 elements to generate 1 Volt it should have given 150 Volts unloaded. It consumed 22 pounds of coke per hour. From Volume 4 of "Electrical Installations" by Rankin Kennedy