Thomas Savery
Thomas Savery (* 1650 in Shilstone , Devonshire , † May 1715 in London ) was an English engineer and inventor .
Thomas Savery originally dealt with shipbuilding , so he invented a ship propulsion system using a paddle wheel . Later he turned to pump technology .
The steam pump
Savery built on Denis Papin's atmospheric piston steam cylinder and designed a pistonless steam pump for which he received an English patent with a term of 14 years on July 2, 1698 under the name The Miner's Friend . The name of the pump is the result of a problem of the time: the pit water had to be pumped out of the mines . This was done manually or by horse- powered göpeln and water arts . As the mines grew in size and depth, this drainage became the determining factor in the profitability of the mine. On June 14, 1699, Savery was able to demonstrate a model of his steam engine at a meeting of the Royal Society . In the same year, the Fire Engine Act (law on fire-powered machines) extended the term of protection for all relevant patents in parliament : Savery's patent did not expire until 1733. The lack that his patent contained neither a functional description nor a sketch, he remedied beside the mentioned demonstration with the treatise The Miner's Friend; or, An Engine to Raise Water by Fire ("miner's friend or a machine for raising water by fire"). Even his patent, which was extended during the term, extended in general to all machines that lift water with the help of fire.
Working principle
Savery's construction is a direct-acting pump, in which the water vapor generated in a steam boiler lifts the water directly through its expansion and reduction in volume when it cools.
The pump consists of a pressure vessel which is connected to the suction (inlet) and pressure line (outlet) via check valves b and c. If the hot steam from the steam boiler flows into the container via control valve a and expands in the process, it presses part of the water in the container into the pressure line via a check valve. Now the steam supply is stopped and the steam begins to condense, the check valve in the pressure line closes. With further condensation, a negative pressure arises in the pressure vessel, which opens the non-return valve of the suction line and sucks water into the pressure vessel. The incoming water increases the condensation. When the control valve is opened, steam flows into the pressure vessel again and the work cycle begins again.
To accelerate the condensation, the pressure vessels were externally cooled with water, this increased the pumping frequency, so the pump ran faster. The Savery pump also works with just one pressure vessel; however, the construction with two pressure vessels has the advantage that the steam removal from the steam boiler is more even. Furthermore, the pumping capacity naturally doubles with twice the steam consumption. Even if the control valve on the demonstrators could be operated by hand, the series devices were controlled by floats . During operation, the pressure vessels are alternately acted upon by a control valve with steam.
Problems and efficiency
Savery was convinced of the efficiency of his machine; However, it had some serious shortcomings: it could only lift the water column by 12 meters; For greater depths, several pumps had to be connected in series. At the time, the required steam pressure was at the limit of what was feasible, for which not only the soldered joints but also the steel and the rivets used at the time were responsible. Therefore the pumps and especially the steam boilers had to be repaired frequently. Due to the design, the steam also heated the water to be pumped. This resulted in a thermodynamic efficiency in the per thousand range, so that the pump could practically only be used in or near coal mines due to its large coal requirement.
Cooperation with newcomers
Savery's patent was so broad that it could impose a partnership on Thomas Newcomen , who invented the technically superior atmospheric steam engine in 1712 . Just like Papin's, Newcomen's steam engine is a piston-cylinder system.
Further developments
It was not until 1872 that the principle of the piston-free steam pump was decisively further developed in the form of the pulsometer .
Web links
Individual evidence
- ^ WHG Armytage: A Social History of Engineering . Westview Press, 1976, ISBN 0891585087 , p. 86.
- ↑ Thomas Savery : The Miner's Friend: Or, an Engine to Raise Water by Fire . S. Crouch, London 1827, p. 65.
- ^ JA Ewing: Encyclopaedia Britannica , 9th edition, Volume 22, Charles Scribner's Sons, New York 1887, p. 473.
| personal data | |
|---|---|
| SURNAME | Savery, Thomas |
| BRIEF DESCRIPTION | English engineer and inventor |
| DATE OF BIRTH | 1650 |
| PLACE OF BIRTH | Shilstone , Devonshire |
| DATE OF DEATH | May 1715 |
| Place of death | London |