Half Sized Blog Element (Single Author Style)
Half Sized Blog Element (Multi Author Style)
The Scoop on Oil Skimmers: Determine the Right Design | Abanaki
The Scoop on Oil Skimmers: Select by Application
Full Sized Blog Element (Big Preview Pic)
For industrial oil skimming, there are six basic designs commonly used in moving media skimmers. (Suction skimmers are excluded, as they are generally unsuitable except for relatively thick (1/4 inch) layers of oil; otherwise they tend to ingest large amounts of water.)
In more demanding situations, skimming is a cost-effective means of removing most of the oil before using more complicated and costly treatments, such as coalescers, membrane filters and chemical processes.
Belt-Type Skimmers
Belt-type skimmers use an endless belt of stainless steel, elastomer or polymer medium, which is lowered into the tank or vessel to be skimmed. The belt passes through the fluid, and then through the skimmer’s resilient wiper blades where the oil is removed from both sides of the skimmer medium. Removal rate is not affected by belt length. The length is chosen to ensure contact with the liquid at its lowest level. The belt length should also allow easy mounting of the skimmer where oil discharge is convenient, and assure easy access for routine service. Lengths up to 100 feet or more are possible.
Mop Skimmers
Mop skimmers use an endless medium shaped like a rope that has mop-like tendrils that pick up the oil. As the medium leaves the liquid and enters the drive unit, it is pressed and wrung out with pinch rollers. For higher viscosity oils, this medium tends to mat down and lose effectiveness. Generally, a decantation system must be used with these units, as water pickup can be quite high. Also, replacement mops tend to be more expensive than belt type media.
Large Tube Skimmers
Large tube skimmers use a floating plastic hose that snakes out over the surface of the liquid and is then drawn back through the drive unit where oil is removed. This design requires a relatively large amount of fluid surface area for proper operation. Length considerations are the same as for belt skimmers; a typical tube diameter is 1 inch. 
Mini Tube Skimmers
Mini tube skimmers are very similar to the larger tube units, but typically have either a 3/16-inch or a 5/16-inch diameter tube. The 5/16-inch diameter is preferable as it has enough stiffness to not drag on the housing and prematurely wipe off oil when drawn into the unit. Pickup rates vary from 1 quart/hour to 1.5 gph, depending on diameter and speed. These units can be used where space is limited. Units that have the motor mounted underneath reduce the amount of space required over the rim of the tank to nearly zero.
Disk Skimmers
Disk skimmers rotate a disk-shaped medium through the liquid. Oil is wiped off and discharged into a collection container in a manner similar to belt skimmers. When specifying disk diameter, it is important to consider reach, the portion of the disk that actually gets immersed. Less disk area in the fluid means less oil removed. Obviously, fluctuating fluid levels can be a real problem.
Also, it is important to look at how much of the disk the wipers are actually wiping. If they wipe only 2 inches from the edge, then any reach into the fluid beyond 2 inches is wasted. As a result, removal capacities for disks can be relatively low.
Drum/Barrel Style Skimmers
Drum/barrel styles are similar to the disk type, but use a rotating drum-shaped medium. Compared to disk types, they are usually more rugged and have higher removal capacity. These units can also be rendered ineffective by fluctuating fluid levels.
When properly selected and applied, oil skimmers are highly economical solutions for separating oil from water to allow its reuse or safe disposal.
All of our coolant skimmers are rugged, reliable and low maintenance. Removal capacities range from 1 to 200 gallons per hour. Browse the types of oil skimmers and oil skimming accessories in our website www.abanaki.com or contact our experts at 440-543-7400 to find the right solution for your application.
Unfamiliar with our Oil Skimming products? Go to the Skimmer Selection page to view the types of oil skimmers for every application.
Watch this video to see how do industrial belt skimmers work.
There are several types of industrial oil skimmers. Choosing one best suited for your application will maximize oil removal while minimizing capital outlay and skimmer operating costs. You may define the application in terms of the following characteristics:
Operating Conditions
The performance and life of the pick-up medium, wiper blades, pulleys, etc. are affected by operating conditions. These include temperatures in and out of the liquid, the pH of the solution and the presence of solvents or other reactive chemicals.
Hazardous Materials
Applications involving flammable materials or explosive vapors require the use of explosion-proof (or air-driven) motors and controls.
Temperature/Viscosity
All skimmers require floating oil to be in a liquid, free-flowing state. (See Note 2 under Table 1 for an exception.) If the oil congeals or solidifies at ambient temperatures, the reservoir and/or skimmer will require heaters to maintain fluid flow.
Removal Rate
Skimmer removal rates, expressed in gph, vary with oil viscosity. Typically, manufacturers rate skimmers using SAE 30 weight motor oil at 65 degrees Fahrenheit (18 degrees Celsius). It’s wise to ask for test data, especially if your application involves a much different viscosity. Your skimmer selection should be based on the maximum amount of oil to be removed within the shortest available time. For instance, suppose total oil influx is 200 gallons a day. The calculated average would be 200/24 = 8.3 gph. However, if most of it comes during a single 8-hour plant shift, you probably need a removal rate three times that average, especially if you need to prevent the discharge of contaminated water to a sewer system. As a rule of thumb, specify approximately twice the maximum capacity you anticipate needing for normal conditions.
Skimmed Water Content
All oil skimmers pick up some water with the oil. Suction skimmers pick up more water than other types. High water content increases oil recycling and disposal costs. Generally, the ratio of water to oil decreases with thicker films of floating oil and slower moving pick-up media. A concentrator or decanter installed at the skimmer discharge port provides secondary oil/water separation that can reduce water content to nearly zero.
Residual Oil
A skimmer removes oil as long as it is present. Depending on oil influx rate and the skimmer’s removal rate, residual oil in the water may be as low as a few parts per million. When further reduction is required, a secondary removal stage such as membrane filtration may be needed.
Portability
In some plants mobile equipment service shops and at remediation sites, a portable skimmer can sometimes service multiple machines, sumps or wells.
Tank or Sump Characteristics
The location, shape and capacity of a tank or water impoundment are major factors in choosing the right skimmer. Also consider fluctuations in water level, turbulence and possible emulsions. Although skimmers do not cause emulsions, they may have trouble removing certain types.
Size/Design
Oil and water can emulsify when subjected to turbulence and other mechanical agitation. Avoid this by having water return to the tank below the liquid surface at as low a velocity as practical. Make sure the tank or sump provides quiet areas, weirs and sufficient volume to allow adequate time for oil/water separation.
Shape
Tanks without nooks and crannies for oil to accumulate in are best. If you have an irregular shape, put the skimmer where the largest amount of oil accumulates. Consider a means of directing oil toward the skimmer such as a floating boom or baffle plate.
Location/Installation
Questions to ask about the physical location and characteristics of the tank and collection container: Does skimmed material need to be pumped from the skimmer to the container? Will skimmer access for periodic maintenance be a problem? How much mounting space is available? Are tank or container modifications required? (Total skimmer system costs may involve additional components, tank modifications and skimmer maintenance.)
All of our coolant skimmers are rugged, reliable and low maintenance. Removal capacities range from 1 to 200 gallons per hour. Browse the types of oil skimmers and oil skimming accessories in our website www.abanaki.com or contact our experts at 440-543-7400 to find the right solution for your application.
Unfamiliar with our Oil Skimming products? Go to the Skimmer Selection page to view the types of oil skimmers for every application.
Watch this video to see how to remove a higher amount of tramp oil.
Abanaki Corporation Oil Skimming Division
17387 Munn Road
Chagrin Falls, OH 44023
Phone: (440) 543-7400
Email: skimmers@abanaki.com
Fax: (440) 543-7404
ISO 9001:2015 Certified Company
Terms and Conditions
The Scoop on Oil Skimmers: Determine the Right Design | Abanaki
The Scoop on Oil Skimmers: Determine the Right Design | Abanaki
The Scoop on Oil Skimmers: Select by Application | Abanaki
The Scoop on Oil Skimmers: Select by Application