- Published in Milestones.
Alfred Büchi’s career was probably already planned out before he was born. His father worked for Sulzer, a mechanical engineering company that he would later work for too as head of the diesel engine research department.
Büchi studied at the Federal Polytechnic Institute of Zurich, graduating in 1903, before starting a succession of engineering jobs in Belgium and the UK. It was during this time that he began experimenting with turbocharging technology to improve the efficiency of the combustion engine.
Büchi stated in his 1905 patent that internal combustion engines have very low efficiency because two-thirds of the energy is lost through exhaust heat. He wanted to capture that heat and use it to improve the engine.
His design for a “highly supercharged compound engine” was simple, using an axial compressor, radial piston engine and axial turbine on a common shaft.
The technology’s principles were identical to those of today’s turbochargers. Power was increased by forcing additional air into the cylinders, with the heat from the exhaust gas used to drive the turbine.
When Büchi returned to Switzerland he was taken on by Sulzer, working in the diesel engine research department, but he never stopped investigating the benefits of turbocharger technology.
In 1911 an experimental turbocharger plant was opened to explore the technology further, and Büchi produced the first prototype in 1915. He demonstrated how it could be used on aircraft to counter the problem of reduced engine power levels in the thin air at high altitudes. It was a disaster.
Although the turbocharger worked, it was less than reliable and could not maintain the boost pressure required. This meant that, although he approached companies such as Brown Boveri (now ABB) in Baden to take the technology on, none was interested because it was considered “undesirable and uneconomical”.
The failure of his demonstration didn’t deter the persistent engineer, and he continued his work, filing a second “scavenging patent” in 1915.
It was to be another 10 years before Büchi succeeded in producing a turbocharger that worked – consistently.
He had always maintained that combustion engines just weren’t efficient enough, and in 1925 he succeeded in mating a diesel engine to one of his turbochargers, improving the efficiency by more than 40%.