Persian windmill
The Persian windmill is a type of horizontal windmill , i.e. H. a windmill with vertical upright rotor axis of rotation . It bears its name because of its historical origin in Persia .
history
The history of the Persian windmill can be traced back to the 7th century. This makes it the oldest known type of windmill. The Chinese windmill is probably the older, but not yet undisputedly proven variant of an equally vertical axis windmill .
In some regions of the former Persia, Persian windmills are still used today. They can be found particularly in the Iranian - Afghan border area. Here you use the strong "wind of 120 days" , which blows with great constancy from the north in the summer months. Most numerous are the mills in the Iranian regions Khorasan (provinces North and Razavi Khorasan ) and Sistan and here again on the plateau of Zosan, south of Khaf . Probably the most famous group of mills is here in Nashtifan ( 34 ° 25 ′ 56.3 ″ N , 60 ° 10 ′ 30.9 ″ E ). The name of the place itself (Nashtifan) means "biting wind" .
Function and design
The Persian windmill rotates on a vertical shaft and drives the millstone attached to it below . A vestibule shaped like half a tower covers one half of the wind turbine. Since this construction is firmly aligned with the main wind direction, only this one wind direction can be used. The drive elements standing as flat, straight blades in a star shape around the rotor axis of rotation are made up of wooden planks; wooden frames covered with mats or branches are also used as drive surfaces in the wood-poor area.
The Persian wind turbine is a propulsion or resistance runner , similar to the cup anemometer . However, lift runners with aerodynamic wings, blades or sails, such as the Savonius rotor , Darrieus rotor or even the Chinese windmill with its junk sails ( lug sails ) that adjust themselves to the wind, are more powerful . All of these types have the common feature of the Persian windmill: the vertical rotor shaft to which the blades, sails or blades are attached.
literature
- Michael Harverson: Persian Windmills . Bibliotheca Molinologica, Volume 10. The International Molinological Society , Reading 1991, ISBN 90-73283-03-5 .
Web links
Individual evidence
- ^ H. Tale: History of Iran's Wind Energy Technology . In: Events . Magazine. September 6, 2004. Tehran, Iran 2004 ( full text on events.ir). Full text ( memento of the original from October 22, 2007 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Snekooei: The world's oldest windmills in Iran; still working! (Video) YouTube , accessed May 4, 2011 .
- ↑ Photos: Centuries-old Windmills of Nashtifan in Iran. Payvant, November 21, 2010, accessed May 4, 2011 .
