Ash Drum

The Basics of Oil Skimming – How It Gets Done with the BP "Big Spill/Leak" in the Gulf

At SkimOil, Inc. we make and sell oil skimmers and oil water separators.

The purpose of this OilyNews newsletter is to give you a short overview of oil skimming and the equipment and a few of the ways to get it done…NOT to sell you oil skimmers—but we would!

We do NOT usually sell to the spill response contractors, except when there are spills, and unlikely as it is—when they need more of our type skimmers NOW. The spill contractors already have a LOT of skimming equipment and containment boom. They have HUGE buying power so they get it on the "relative cheap" and then they store it and keep it ready—WITH TRAINED TEAMS—standing by.

American companies who have a lot of oil to spill or leak, must have a registered spill plan with the EPA or 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 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 rotary 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.

The oil skimmer business on a daily basis is like most others… long moments of routine—interrupted by short bursts of chaos and madness. Business is good without big spill incidents, thank you. But do keep in mind… we always have a lot of skimmers in stock— ready to go NOW!

We don't have the time to go into great detail here and now—but we'll be sending out more "OilyNews" updates on skimming as the BP/Deepwater Horizon exploration rig Gulf oil spill and blowout proceeds—which it's certain to do.
God help us all if the weather doesn't help!

What's an oil skimmer and how is it different from an oil water separator?
The short version is that oil skimmers are for removing free floating (gross) 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. Today we're talking oil skimmers and the types available.

Spill response contractor equipment is mostly like our industrial skimmers—just much larger and heavier duty.

Selective Floating Skimmers Give You Oil Only!

These skimmers give you as little as 3% water—but the Gulf oil right now is being emulsified with up to 50/50 water—YIKES

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 some-where 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.

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 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.

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 pickup 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 surface skimmer.

The surface of the liquid is going to be drawn 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 be drawn 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 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 FWS 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, 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 surface. If this floating weir skimmer is sitting in pure oil—you can move huge amounts of oil fast without getting water along with it!

Here are some general application ideas about which skimmer to use where:

 

Floating Oil Skimmers

- Hook a hose to it and put it into the water.

- Hook the other end of the hose to a pump—start skimming!

- Capable of high recovery rates—usually measured in gallons per minute.

- Floating drum skimmers—for removing a lot of oil without water—FAST or use with very heavy oils—the toughest and most effective skimmers made. Hydraulic or air powered.

- Floating disc skimmers—same as above but somewhat more delicate—probably not so good where it gets moved around a lot. Hydraulic or air powered.

- Floating weir skimmers—real workhorse-type skimmers, the only skimmer that will remove sheen or floating stuff other than oil. Works great with a vac truck or AOD pumps.

 

Hard-Mounted / Installed Skimmers

- Low recovery rate—usually measured in gallons per hour.

- Belt skimmers: electric, great for reaching down into a pit or well or tank and lifting the oil to the surface. Requires no pump. Usually rather lower recovery rates—low maintenance.

- Rope mop wringer skimmers: have a LOT more surface area than belts; the rope usually looks like a squirrel tail, often used/stretched across a pond or tank, has wringer rollers—won't tolerate high solids content. Electric, air or hydraulic powered. Higher maintenance.

- Tube type skimmers: same idea as above—uses a hose-like tube that dances on the surface to gather oil. Recovery rates to 40 gph. Low maintenance.

 

As always—experience helps with skimmer applications. SkimOil, Inc. has all the skimmer technologies known to man. This is what we do all the time, so we can bring highly specialized knowledge and experience to your requirement—giving you the right technology so we can get it right—the first time. If you need a skimmer—FAST—or in a while, CALL!

Learn more about oil skimmers here:

http://www.skimoil.com/oil_skimmers.htm

Learn more about oil water separators here:

http://www.skimoil.com/oil_water_separators.htm

About the Author

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.

 

Phone:  (314) 579-9755
Fax:  (314) 558-9253

Website:  http://www.skimoil.com
E-mail:  info@skimoil.com

 

Ash Drum

Comments are closed.