/program/kjy/2006 08 30/ 10 1395 . shtml
Squeezing is an oil recovery method with a long history. As early as Yao Minshu, the State of Qi in the Fourth Association of Northern Jia Wei, there were records of oil squeezing. Wang Zhen's Agricultural Book in the Yuan Dynasty, Tiangong Wu Kai in the Ming Dynasty and Agricultural Administration Quanshu all recorded oil presses and methods of oil pressing.
In the lobby of a hotel in Chaoyang District, there is an oil press, which is said to be the most complete and largest manual oil press in China today. It comes from Chaling mountain area in Hunan. Its main part is made of a camphor tree that has been growing for 300 years. After being used locally for more than 200 years, it was moved here by the boss who likes to collect in this hotel.
Because there are abundant tea seeds in the mountainous areas of Hunan, local farmers will dry the tea seeds in the slack season, mash them, add straw to make oil cakes, fix them with iron hoops and put them into the press room of an oil press to extract oil.
In the horizontal wedge oil press, after the oil cake is put into the press chamber, the wooden blocks are stuffed into one side of the oil cake, and then the triangular wedge between the wooden blocks is hit with the hanging ram. When the wedge is driven into the press chamber, the wood blocks placed horizontally in the press chamber will produce extrusion force on the oil cake. Because this triangular wedge plays an important role in the process of oil extraction, this kind of oil press is called wedge oil press.
With the increase of power, clear tea oil will flow out. This kind of oil press can also squeeze peanuts, rapeseed and other oils, and can squeeze out hundreds of pounds of oil a day and a night.
According to experts' speculation, the big wedge oil press may have appeared in the Northern Song Dynasty, when it was already very advanced. It was their appearance that led to the emergence of real professional oil-squeezing workshops. In the long years of Song, Yuan, Ming and Qing dynasties, it was this kind of oil-squeezing equipment that provided sufficient edible oil for Kaifeng, Beijing, Nanjing, Hangzhou and other emerging metropolises.
Interview with Li Chenghao, Conon senior engineer of Samos Yuhuan Institute of Mechanical Technology, Beijing: According to accurate historical data, this old-fashioned wooden oil press has been popular in China for almost 700 years, and it may have existed for more than 1000 years. Until 1959 after liberation, there were150,000 wooden oil presses in China, accounting for 40% of the national output, reaching 65,438.
This traditional oil recovery method relies on manpower to complete most of the work, which is very labor-intensive. To make a cake, you have to bend six times. After eating the cake, three people bumped into each other, and all three were very tired. After the first one is done, you should take the cake down, tear it off and hammer it. Then you can grind it, and then you can make two cakes. Then you can hit three people. It's torture