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In the previous article, the author talked about how Parsons used new machining tools and techniques to make gears, and the application of the steam turbine in electric generators. Here, he discusses the first axial flow compressor.
Parsons thought correctly after he had invented the reaction steam turbine that the expansion process could be reversed and a multi-stage axial flow air compressor would be possible by reforming the rotating blades to become fans and then stage by stage air could be compressed. He invented the axial flow compressor in 1901 and called it “The Turbo-Blowing Engine”. At a normal speed of 3000 RPM the compressor-blower put out 10 psig and delivered 21,000 cfm of free air. He built a number of these highly successful blowing machines for steel mills.
At 3600 RPM the machine would put out 19 psig. These machines were oil-free and far superior to the old reciprocating compressors because they gave a continuous and steady flow compared to the pulsating flow of the reciprocating ones. The cross-sectional drawing shows that there were about 15 stages of rotating and stationary blading. These machines were truly axial flow compressors.
Parsons also designed and built three-stage axial flow exhaust machines for the blast furnace industry. These exhaust compressors only produced about 3 psig of pressure and were also driven by steam turbines at 8000 RPM and only delivered about 3 psig of hot exhaust flow. Nevertheless, they were in reality, axial flow compressors. These air blowers and exhaust blowers were not very efficient, being only about 70 %. These machines were only used for a few years and then centrifugal blowers took their place, which were about 78 % efficient.
Investigation of internal combustion gas turbines
In 1903, Parsons thought that the steam turbine cycle could be simplified by eliminating the boiler and condenser if firing could be done directly before the turbine expander. He and his associate Stoney ran experiments by expanding hot air through a nozzle and then measuring the downstream temperature. He found out that there was no temperature change because of the impact of the gas on the measurement device. He therefore thought that the internal combustion gas turbine could not be made; but it turned out that he was wrong. However, it took many years until 1936 before it became a reality with the introduction of the Houdry process by BBC.
Nevertheless, Parsons did invent and develop two components of the gas turbine, the reaction steam turbine that could be used to expand combustion air to produce power. He also invented the axial flow compressor that was used by BBC for the first gas turbines, starting with the Houdry unit in 1936 and followed by the stand alone 4000 KW turbine generator set in 1939.
Parsons started building steam turbine electric generator sets in 1890 in his first shop at the Heaton Works of Messrs. C. A. Parsons and Company, about two miles to the east of Newcastles-on-Tyne. After the success of his small ship “Turbinia” in 1897 he expanded to make steam turbines to power ships by building a second manufacturing facility at his Marine Turbine Works at Wallsend-on-Tyne. He continued to manufacture steam turbines and later ship gears at both plants for both applications of power generation and ship propulsion.
Parsons was quite generous with his patents and steam turbine designs and gave licenses to a number of other companies including Brown Boveri of Switzerland and Germany, George Westinghouse in the United States and John Brown in England. Parsons actually could not keep up with the demand for his turbines and fortunately he was willing to offer his patents and designed to these other companies to help satisfy the need for this new power producer which was a huge step forward from the 100-year-old James Watt recip steam engine.
General Electric did not license the Parsons reaction steam turbine designs and instead decided to use the US Curtis impulse patents to start manufacturing vertical shaft steam turbines to compete against Westinghouse. It was only a few years until GE realized that it was much better to produce horizontal shafted turbines and so dropped the vertical arrangement. Also, after the Parsons patents expired, GE started applying reaction blading downstream of one or two impulse sets of blades to give better expansion efficiency.
Parsons activity (1911-1931)
Parsons played an important part in the development of efficient search lights for the Naval and Military technicians by producing at reasonable cost silvered reflectors and increased the size of the small reflectors to ones over 7 feet in diameter. He produced search lights of all kinds and designs.
Then in 1921 Parsons became interested in optical lenses and acquired a controlling interest in the firm of Ross Ltd. of Clapham, London, well known for making binocular and other optical devices. Prior to this, England had to import most of these devices for war purposes. He bought out the whole company and re-named it ‘The Parsons Optical Glass Company.’ He made many improvements in making lenses and established his company as a leader in making quality English optical glass. He was responsible for increased interest in telescopes and astronomy.
In 1925, he bought out the old Grubb and Sons Company of Dublin. He invented the Auxetophone, a device for the amplification of music and vocal sounds without any tone-distortions. He also worked on making artificial diamonds, the work that led GE to actually make artificial diamonds. He was a truly a great inventor.
Parsons had the courage to take on the responsibility by 1910 of making 70,000 HP steam turbines for the Lusitania and Mauretania increasing the power needed from 14,000 HP. He was a modest and kind man, and had many honors bestowed upon him. Parsons died on February 11, 1931, while on a cruise in the West Indies, at the age of 77 years. He gave the World the wonderful steam turbine that we use today to generate electric power the world over and to propel our many large ocean-going vessels.
Steam turbine development after 1911
The steam pressure used at the time of 1911 was low of about 150 psig and the superheat was no more than perhaps 100 oF. The steam turbine blading was made out of copper. Then came steel tubing which made possible higher pressure and temperature boilers for the steam turbine. Steel was then used to make turbine blading. Advancements were made in the steam cycle such as re-heat and feed water regeneration. The steam pressures and temperatures shot way up as we know.
Looking back over a 25-year period from 1885 to 1910, a number of great inventions and developments took place that greatly advanced civilization. There was of course the Parsons revolutionary steam turbine. The airplane was invented by the Wright brothers. Tesla invented the AC motor and other AC devices and invented the radio. Westinghouse, GE and BBC put AC power across. Edison came up with his gadgets such as motion pictures. Then Ford came out with his mass produced model T and the assembly line. All these things and many others took place in this short time frame.
Finally, the World would not have the 60% efficient combined steam and gas turbine cycle that is the electric generating system of the future burning the newly-found environmentally-friendly shale natural gas produced by fracking we now have available today if it were not for the development of the steam turbine by Sir Charles Algernon Parsons.
Ivan G. Rice was past chairman of the South Texas Section of ASME (1974 - 75), past chairman of the ASME Gas Turbine Division (now IGTI) (1975 - 76). A Life Fellow Member of ASME and Life Member of NSPE/TSPE, he has authored many articles and ASME papers on gas turbines, inter-cooling, reheat, HRSGs, steam cooling and steam injection.