Flotation demonstration
Description
Demonstration of flotation by Catherine P. Foster, Upper Tigris Archaeological Research Project (Kenan Tepe, Turkey). Machine based on standard Siraf-type flotation tank (Nesbitt and Samuel 1989; Williams 1973). The machine was operated on a level concrete walkway situated within a shady corner of the fire station yard in Bismil, Turkey. Water derived from an adjacent well where water was continuously pumped into a small holding tank and flushed away toward the river via a man-made sluice. A second electric generator pumped water from the holding tank into the flotation machine through a 1-inch valve.
Creator(s)
Bradley J. Parker, Catherine P. Foster
Date
2007
Duration
3:46
Compression
.MOV
Director
Bradley J. Parker
Transcription
This is our flotation tank, her name is Brooke. It basically consists of a large metal drum and you have two side trays, which hold two meshes: one is a 1-mm mesh, the smaller one is .25 mm mesh, and inside the tank here we have a 1-mm mesh. The idea with flotation is that we fill the tank with water, and our water comes from our local spring source, it will go through the motorized pump located here and then injected into the tank through these valves. Now once we add the sediment to the water, small carbonized seeds and other flotation remnants will come to the top and we’ll bring the water level all the way up to the spout and the water will be gently going over the spout in a kind of waterfall effect.
This is our sample; it derives from a house floor. What we’ve done is put it in a bucket and measured the volume and now we are going to introduce it into the flotation tank. Go very slowly because you don’t want to splash. And what you will see almost instantly is that charred seed and charcoal will come to the top. Now if you get too much in there you want to make sure and add more water and you can do that by adjusting the valves that are on the side and also the sludge outlet that we have on the bottom.
Once we’ve added our sample to the flotation tank you want to gently agitate it with your hand being very careful and what you’ll begin to see are charred seeds and charcoal that float to the top of the water.
Once the heavy fraction has been cleared of all sediment, I’m going to close the sludge valve so the tank will fill up. Once the tank is filled you’ll see the water will begin cascading out and into the nested sieves that we have at the side of the tank. What will begin to happen is that the charred seeds and charcoal will then begin flowing into the nested sieves.
This is our sample; it derives from a house floor. What we’ve done is put it in a bucket and measured the volume and now we are going to introduce it into the flotation tank. Go very slowly because you don’t want to splash. And what you will see almost instantly is that charred seed and charcoal will come to the top. Now if you get too much in there you want to make sure and add more water and you can do that by adjusting the valves that are on the side and also the sludge outlet that we have on the bottom.
Once we’ve added our sample to the flotation tank you want to gently agitate it with your hand being very careful and what you’ll begin to see are charred seeds and charcoal that float to the top of the water.
Once the heavy fraction has been cleared of all sediment, I’m going to close the sludge valve so the tank will fill up. Once the tank is filled you’ll see the water will begin cascading out and into the nested sieves that we have at the side of the tank. What will begin to happen is that the charred seeds and charcoal will then begin flowing into the nested sieves.
Contributor
Catherine P. Foster
Citation
Bradley J. Parker, Catherine P. Foster, "Flotation demonstration," in MicroCommons, Item #61, http://www.microcommons.org/items/show/61 (accessed June 19, 2013).
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