Skimmers are devices that are used to recover spilled oil from the water’s surface. They can be self-propelled, used from the shore, or operated from vessels. There are three types of skimmers and their effectiveness depends a great deal upon conditions at sea. If the water is moderately rough or choppy, the skimmers usually recover more water than oil. Each type of skimmer has both advantages and disadvantages which depend upon:
- The type of oil being recovered.
- The condition of the sea during cleanup.
- The presence of ice or debris in the water.
Types of Skimmers
Weir Skimmers
These skimmers use a dam or enclosure which is positioned at the interface of the oil and water. The oil, which is floating on the surface, will spill over the dam and be trapped in a well that is inside. The goal is to trap more oil than water. Then, the trapped mixture is pumped out through a pipe or hose to a storage tank for recycling or disposal. These skimmers have a tendency to become jammed and clogged by floating debris.
Suction Simmers
These skimmers operate like a household vacuum cleaner and suck up oil through wide floating heads. Then the sucked up oil is pumped into storage tanks. These skimmers are quite efficient but they, too, become clogged with debris and require constant observation. These suction skimmers perform best on smooth water where oil has collected against a boom or a barrier.
Oleophilic Skimmers – Oil Attracting Skimmers
These skimmers use long belts, disks, or continuous mop chains of oil attracting materials, which blot the oil up off the water’s surface. Then, the oil is squeezed out or scraped off into a recovery tank. Oleophilic skimmers have the advantage of flexibility, which allows them to be used on spills of any thickness. Certain types, like the chain or ‘rope-mop’ skimmer, work well on water that is choked with debris or ice.
Skimmers may not be carried by your regular industrial supply company and may have to be ordered from specialty companies.
Rope Pom Pom Skimmer
This is an oil attracting skimmer. It was developed for the recovery of thick, oil-based liquids and has thousands of individual strands. These strands are capable of holding oils that are 10 to 50 times their weight and it works well at below freezing temperatures. This skimmer can be used in oil/water separators and is very efficient in cleaning up around stumps, rocks, or pilings. If the pom poms are on a rope, they can be secured to the shoreline for use in open water. These skimmers or sweeps are quite cost effective and are important to have on hand for any facility that maintains oil next to an open waterway.
Ultra Passive Skimmer
This is a unique polymer absorbent type of oleophilic skimmer, which bonds oil to its polymer matrix and prevents leaching. It will not cause ponding or clog with debris. This skimmer is smaller and floats on the water’s surface, continuously absorbing oil.