How to Get Oil Off Water - The Basics of Oil Skimming

Oct. 25, 2010 - PRLog -- At SkimOil, Inc.® we make and sell oil skimmers and oil water separators - and want to give you a short overview of oil skimming and the equipment and a few of the ways to get it done.

Most people who use our skimmers are using them for industrial or process applications where oil may be leaked or spilled—but it’s usually in contained areas, where they have some control and can keep it from getting off their property.

Who uses skimmers?
American companies who have a lot of oil to spill or leak, must have a registered spill plan (SPCC) with the EPA and USCG.

Our normal customer base for this type of skimming includes refineries, well sites and the petroleum industries, but also included are steel mills, power plants, metal fabricators, chemical plants, wastewater treatment plants but also oddly enough—food oil facilities, cereal manufacturers, and even cardboard manufacturers and coffin makers. There’s a lot of oil that has to be cleaned up.

Consider—almost every elevator in the USA has a pit under it to catch any oil that could leak into it. Our Oilsmart switches and Oilsmart alarms keep that oil from being pumped out into the environment. The Clean Water Act makes it illegal to put more than 15 ppm of oil into our waters. Big fine$ await polluters.

American companies who have a lot of oil to spill or leak, must have a registered spill plan (SPCC) with the EPA and USCG. These companies who own or handle the oil usually have an agreement with Oil Spill Response organizations (OSRO’s), contractors who have a LOT of trucks and boats stationed all around the country full of spill equipment on standby. These are usually highly trained professional teams—but the brunt of the work is done by the local labor pool with lower cost manual labor, sometimes with minimum OSHA 40-hour training.

People with oil to spill often have their own equipment and trained "First Response Teams," but that’s usually just until the (OSRO) spill response contractor gets onsite. Often at a spill scene, the on-site coordinators or "agency overseeing things" sometimes decide they need more of a certain type of floating weir skimmers or floating drum skimmers… we like that, but most of our day to day business is industrial or process type skimming and not needed for sudden service.

What’s an oil skimmer and how is it different from an oil water separator?
http://www.skimoil.com/oil_skimmers.htm

Oil skimmers are for removing free floating oil from the surface of water, while oil water separators are flow thru devices for removing free and un-emulsified oils from a moving stream of water—sometimes down to a parts per million (ppm) level.

Ocean Spill response contractor equipment is mostly like our industrial skimmers—just much larger and heavier duty. For skimming at or near shore—the skimmers you’ll see here and at www.skimoil.com are the common tools in every spill contractor’s arsenal.

Selective Floating Skimmers Give You Oil Only!
These skimmers give you as little as 3% water!

The selective type oil skimmer is always motor driven and operates by introducing to the oil—a surface (metal or plastic) that the oil is highly attracted to and sticks to. This surface, being a belt or mop or tube or drum or disc, is then rotated around (by the motor) to an oil removal spot, and then wiped or wrung or scraped off, allowing the oil to run off by gravity flow to a sump or tank or trough or somewhere else for eventual removal. The water does not like (very much) the plastic or metal rotating element (drum?)—so you don’t have to dispose of as much water!

Case in point: our floating drum skimmers (FDS) float on the surface of the water/oil and the drum (air or hydraulic driven) rotates slowly thru the oil, getting covered with oil, then rotating around then scraped off by a "doctor" blade allowing the oil to flow into the sump where it collects—then gets pumped away. Consider this to be a two part operation—skimming and pumping.
http://www.skimoil.com/drum_skimmer.htm

Skimming is removing the oil from the surface—and the pumping part moves that oil to storage. If you’re skimming, you gotta’ keep pumping it off or the floating skimmer will turn into a submarine.

These floating drum skimmers are the most efficient way of moving a LOT of oil FAST—and not give you as much water to deal with. These drum skimmers only need a few inches of water to float in. Even our smallest industrial drum skimmer "The Steelmax" which is only 2.5' x 3.5' can skim an amazing 20 gallons of oil per minute—now you can see why you have to keep pumping it out! Very few people have this much oil to skim.

Floating drum skimmers are available to skim as much as 200 GPM.
http://www.skimoil.com/drum_skimmer.htm

An industrial floating drum skimmer can skim from 30-60 GPM—and it’s only 3' x 5' and can be thrown in the back of a pick-up by just two men. These drum skimmers are so FAST that they are the tool of choice on spills…but the oil has to be touching the drum—not always so easy to do.

Sometimes as you’ve seen on the news videos—the oil is not a contiguous mass—it’s fragmented and broken up by waves and wind action, making the drum skimmer not so effective.

But when it’s in oil, a big drum skimmer is an awesome picture—imagine being able to skim 3-4 barrels of oil per minute (100-200 GPM)—without getting much water! It’s all a function of the large amount of surface area on the drums—as long as they touch the oil. These are serious skimmers.

NON-Selective Skimming—
Floating Weir Type Surface Skimmers

Now onto the non-selective type skimmers which do give you a lot of water to deal with. These floating weir type skimmers are like a floating vacuum head—creating a low spot on the surface of the oil/water—allowing everything on the surface near it—to run into that floating low spot. Think of it as a stand pipe or floating drain on the surface.

The FWS floating weir skimmer attracts and influences the surface all around the skimmer—it’s a pure gravity surface skimmer.
http://www.skimoil.com/floating_weir.htm

Click here to see video!
http://www.skimoil.com/floating_weir.htm

The surface of the liquid is going to flow into the mouth or weir and goes down it’s drain which is the suction line to a remote pump. Whatever is on the surface (oil/feathers/fish/trash/water) is going to flow into the skimmer sump by the movement of the water or surface flow across the weir. These skimmers don’t have any motor driven rotating elements, BUT they do require use of a remote pump or vac truck or other suction source to pump away everything that’s running into that floating surface drain. Make no mistake, these will give you a lot of water to deal with if you have little surface oil—but they are FAST and flow rates can range from a few GPM up to hundreds of gallons per minute. Our FWS381 that’s 3' x 4' will skim the surface at up to 400 GPM. We can scale that up to 1000 GPM!

In the ideal world, if you had unlimited storage tanks, this would be the best skimmer, but it gives you a lot of water to deal with along with the oil. Getting rid of oily water is tough itself, giving you a whole new problem with disposal and requires an oil water separator (a flow thru device for separating oil from a moving stream of water).

The floating weir skimmers are also used to skim or remove floating stuff other than oil—such as floating fly ash in power plants, floating duck weed in ponds, grass/ plastic pellets and anything else that floats on the surface and that can be influenced by the motion of water moving across the weir. If this floating weir skimmer is sitting in pure oil—you can move huge amounts of oil fast without getting water along with it! Remember this is a surface removal device.

Call SkimOil® at (314) 579-9755 or e-mail: info@skimoil.com.
http://www.skimoil.com

Oil skimmers and oil water separators in stock now!

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Skimoil, Inc. is a specialty design/manufacturer & distributor of marine & industrial pollution control equipment & systems. We specialize in oil skimmers, oil water separators & wastes reduction for the manufacturing, steel mill, & marine industries.