Sump

From Wikipedia, the free encyclopedia

A sump is a low space that collects an often-undesirable liquid(s) such as water or chemicals.

An example is the oil sump of a gasoline engine. The oil is used to lubricate the engine's moving parts and it pools in a reservoir, known as a sump, at the bottom of the engine. The sump means the engine has to be mounted slightly higher to make space for it, and oil in the sump can surge during hard cornering, starving the oil pump; for these reasons, race engines are "dry sumped" using scavenge pumps and a swirl tank to separate oil from air which is also sucked up by the pumps. ^[1]

Another example might be the lowest point in a basement into which any water that seeps in flows. If this is a regular problem, a sump pump that moves the water outside of the house may be used.

One common example of a sump is in an aquarium, mainly a reef system. The sump sits below the main tank and is used as a filter, as well as a holding place of unsightly equipment such as heaters and protein skimmers. The main advantage of having a sump plumbed into an aquarium is the increase of water in the system, making it more stable and less prone to fluctuations of pH and salinity.

Sump is a term used in caving to describe a submerged passage. Sumps necessarily end normal exploration by cavers. Exploration can be continued only by cave diving as happened repeatedly in the recent exploration of Voronya-Krubera, or by emptying the sumps of their water, siphoning the water away through use of hoses. This is, of course, only practical in upstream sumps, as downstream sumps require cave diving in order to reach a lower level to allow the water to be siphoned off. Upstream sumps have been successfully emptied using hoses to siphon water out of them at the Sinkhole Dersios (-164m) during 2005. The water was sent deeper into the sinkhole and the emptied sumps revealed virgin passage behind them. A third method, emptying the sumps by pumping is only really practical when the sumps are close to the cave entrance, as at the sinkhole Peleta (-493m) in Greece. Pumping the water away will require that the inward flow of water into the sump be less than the rate at which the pump empties it, as well as a suitable place to collect the emptied water. At Peleta, the water was emptied outside the entrance to the sinkhole. During the rescue at Sarkhos Cave (-220m) in 2002, the water was collected by pumping, slightly above the flooded sump through the construction of a suitable watertight area some meters higher than the sump. Some manuals mention the use of explosives or other forms of force to empty sumps, but the ecological damage thus done to the fragile cave environment very rarely, if ever, justifies the use of such methods.

[edit] References