Oil skimmers are the apparatus that is used to remove oil that is floats on the surface of any fluid. These skimmers merely float on the fluid, unaffected by the fluid itself, and are designed to attract the floating oil in the fluid. The materials that used in manufacturing the oil skimmers are likely to attract the only oil from the fluid, and not the fluid itself. While oil skimmers are largely used to extract unwanted oil from the fluid, in some cases, they are also used to pre-treat the liquid, as it reduces the overall cost of cleaning the fluid. These skimmers are used on the fluids in preliminary stages to extract as much oil as possible prior to the company employing costly and lengthy procedures to do the same.

Oil skimmers are of many different kinds. There are six major types - namely belt, drum, disk or barrel style, mini tube or large tube, mop and floating suction skimmers. These skimmers are specially designed based on the laws of gravity and surface tension in order to function. The belt skimmer uses a steel belt for the process of cleaning the fluid. The belt is gently lowered into the fluid and it moves through specialized wiper blades, which removes oil from either side of the fluid, as it goes through it.

The disk oil skimmers are designed to function in a slightly different pattern. As the name conveys, these skimmers use a disk, which rotates through the fluid and the oil is whisked off the fluid and deposited into a collection container inside the skimmer. The disadvantage in using this kind of skimmer is they are not practical for places with shallow fluids of fluctuating fluid levels, as the entire disc needs to be submerged to do the cleaning job well.

The next type of oil skimmers is the barrel or drum skimmer, which are quite similar to the disk skimmers, but instead of a disk, a rotating drum is used. The advantages of these skimmers are mainly that they are more durable and are capable of moving more water than disk skimmers. Fluctuating liquid levels, however, are still challenging for the barrel style skimmers.

The mop oil skimmers make use of specially designed ropes to extract the oil from the fluid. The process involves dipping of the ropes into the fluid and removes the fluid and the oil. As the ropes go into the drive unit, pinch rollers are used to wring the ropes dry. The primary disadvantage is that when these are used with the highly viscous oils, the ropes in these oil skimmers tend to lose their effectiveness and get matted down and adding to the maintenance costs, as the replacement mops are costly.

The last two kinds of oil skimmers are the large tube skimmers and the floating suction skimmers. The tube uses a plastic hose that moves over the liquid's surface, drawing the oil through the large tubes. This can be used only on large surfaces, but for smaller surfaces mini tubes can be used in a similar manner. The floating suction skimmers come in an assortment of designs, but each sort includes a floating intake and they are most effective when there are thick layers of oil to be removed.

The oil skimmers are excellent and most effective apparatus to separate oil from any fluid. They are simple devices, but do an excellent job on what they are designed to do. In addition, they are easy to repair, maintain and clean, and therefore, the efficiency of oil skimmers depends largely on how they are maintained. The better you keep your skimmer, the better and longer it will work.