Oil skimmers are simple, dependable and effective tools for removing oil, grease and other hydrocarbons from water and coolants. Often, an oil skimmer by itself can achieve the desired level of water purity.

In more demanding situations, oil 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.

As with any piece of industrial equipment, there are guidelines that should be followed to promote optimal efficiency, as well as a long, trouble free operational life. Let’s take a look at a few tips that will help you get the most out your oil skimmer.

A skimmer is most effective when there is no turbulence in the media

Skimmers rely on the differences in specific gravities between oil and coolant or water that causes oil to float on top of water. In applications where turbulence is present, the process of oil rising to the top will be prolonged, with some oil remaining below the water until conditions allow gravity to ultimately prevail. Operating the skimmer predominantly during quiet times will give oil the chance to rise to surface and allow the unit to operate more effectively.

Keep a spare belt and wiper blades on hand

Being prepared for the unexpected is always good practice. While blades and belt are typically very durable and trouble free, you never want to be in a situation where the skimmer must be taken out of service until a new belt or wiper blades arrive from halfway across the country.

Choose a belt that is long enough so that the tail pulley is submerged when the liquid level is at its lowest point

Water and coolant levels can vary over time. Therefore, the skimmer needs to be capable of collecting oil when the levels are at their lowest. Taking the time to correctly size the belt prior to purchasing the unit will save a lot of headaches down the road.

Properly size the skimmer to the size of tank

Skimmers operate by breaking surface tension which allows oil to be attracted to the belt. If a unit is undersized, it will not have the strength to disrupt the surface tension of the liquid, meaning that oil will never make it to the belt. Sizing of the unit should always be based on the overall area of the tank, not the volume of oil that is expected in the tank. This will guarantee that the skimmer will be capable of overcoming the surface tension that is present for the given tank area.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

You are just one step away from downloading Abanaki's most detailed resource on our oil skimming equipment. Simply click at the button to get your ultimate guide now.

Oil skimmers are tremendously versatile, especially when the wide range of venues where they are called upon to operate is considered. Basically, anywhere oil and water have the potential to mix presents an opportunity for a skimmer to be put to good use, keeping oil out of water or coolant so that it can be recycled, re-used, or safely discharged.

The applications where these unsung workhorses perform are numerous, with skimmers being called upon to keep oil out of the places it does not belong, such as machinery coolant, bilge tanks, and wastewater that is discharged from parking garages. While there are differences in design from one skimmer vendor to the next or variations based upon their application, all skimmers ultimately rely on the differences in specific gravity and surface tension in oil and water to allow them to attract and capture oil. A rotating disc or belt is then used to collect the oil, where it can then be recycled or reused.

Make sure the skimmer is mounted level

It is strongly recommended to take the time during the initial installation to check that the skimmer is mounted and fastened securely in an orientation that is level. This is especially critical for skimmers with free-hanging belts to ensure proper tracking over the pulleys. This will promote better performance and reduce premature wear on the belt, wipers, pulleys, and motor.

Proper positioning of wiper blades is essential

Maintaining the proper amount of tension on the wiper blades is key to optimizing skimmer performance. Striking a balance that allows the blades to contact the belt in a manner that allows them to remove the majority, if not all of the oil from the belt is ideal. Over tightened wiper blades will cause premature wear on blades. Under-tightening leads to poor recovery results, as the oil collected by the belt is not fully removed as the belt passes over the wipers.

Run the skimmer when oil is present

While this may seem like a rather obvious point, running a skimmer constantly may actually be counterproductive, because it increases the likelihood that coolant or water will be picked up by the belt. A timer or an oil in water sensor can be employed to optimize skimmer operating efficiency by controlling the times when the unit is running.

Oil Skimmers Get the Dirty Jobs Done

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

You are just one step away from downloading Abanaki's most detailed resource on our oil skimming equipment. Simply click at the button to get your ultimate guide now.

The location, shape, and capacity of a tank or water impoundment are major factors in choosing the right oil skimmer. Also consider fluctuations in water level, turbulence and possible emulsions. Although oil skimmers do not cause emulsions, they can 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 your 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 oil skimmer where the largest amount of oil accumulates. Consider a means of directing oil towards the oil skimmer such as a floating boom or baffle plate.

Location/Installation

The physical location and characteristics of the tank and collection container are important. Does skimmed oil need to be pumped from the oil skimmer to the container? Will oil skimmer access for periodic maintenance be a problem? How much mounting space is available? Are tank or container modifications required? Cheap oil skimming systems quickly lose appeal when costs for additional components, increased maintenance and expensive tank modifications are involved.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Abanaki Model 8 Belt Skimmer in Operation

I have numerous totes that only need oil skimmed out every once in a while. Do you have oil skimmer that easily movable?

A good fit for this application usually ends up being our Tote-It belt oil skimmer. At about 40 pounds, this unit is easy to carry from one tote to the next. This belt oil skimmer comes in different belt widths and lengths to help customize how much oil will need removed and the tank dimensions.

This level of mobility can eliminate the need for having one belt oil skimmer for every tote or trying to carry around a more cumbersome unit to each tank.

When should I use a belt skimmer and when should I use a tube skimmer?

Belt Skimmers provide the highest pickup rates because belts have more surface area than tubes. Belt skimmers may be mounted on a frame over a sump, pit, or pond, or they may be mounted directly to the top or side of a tank. The pulley is located near the bottom and the belt extends above the fluid surface, accommodating fluctuating fluid levels. Belts are easier to manufacture than tubes and therefore come in a wider variety of materials to meet the specific requirements of the application and the type of oil to be removed. The belt-and-pulley design is simple and reliable, enabling belt skimmers to be used in harsh applications with little maintenance, even in high or low temperatures.

The Tubetastic line of Tube Skimmers can be used in the same applications as belt skimmers, however they have certain advantages. Tubes are useful in applications where there is no top access to the coolant sump. The tube breaks the surface of the oil laden coolant causing oil to stick to the tube. The oil is then wiped off and discharged into the oil collection container.

The Oil Viper Tube Skimmers use a tube that floats on the fluid surface and collects free floating oils in water depths as shallow as a few inches. Increased removal rates over other tube skimmers are achieved because its clean-wipe system ensures the tube is oil-free when it returns to the tank.

My oil skimmer isn’t picking up oil from my coolant sump like it did a few days ago. What is going on?

Your coolant may contain rust inhibitors that are coating  the metal belt causing a barrier between the the belt and the  oil. Try changing to a synthetic belt material such as Elastomer  or Polymer. Rust inhibitors do not affect them.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Oil skimmers usually incur a low initial cost, install easily, offer rugged construction, reliable operation and minimal upkeep. Training personnel for operation, monitoring and routine maintenance is nil.

Still, there are different types of skimmers, and each application requires some analysis to make the best selection. Also, the water collection system must be set up properly in order to get maximum performance from the skimmer.

Reservoir Design

Because skimming acts on floating oil, the water must be in a reservoir where separation can occur. The reservoir should be designed with quiet areas, weirs and sufficient volume to allow adequate residence time for oil/water separation. Avoid turbulence by having water return to the reservoir below the liquid surface at as low a velocity as practical. 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 medium to improve removal efficiency.

Turbulence

All skimmers work more efficiently in quiet water with a relatively thick oil layer. The greater the turbulence, the lower their efficiency due to emulsification. Turbulence also affects the physical performance of a skimmer. For example, a tube-shaped medium may get kinked due to turbulence, which could cause damage or impair its drive mechanism.

Mop type oil skimmers may require a tail pulley with its axle secured to the side of the tank. Belt types may be fitted with a tether or stabilizer bar assembly to resist twisting of the tail pulley.

Skimmer Reliability and Maintenance

Skimmers require a certain amount of routine maintenance, primarily periodic cleaning and checking wiper blade adjustment. Easy removal of safety covers shielding the moving medium and its pulleys will reduce maintenance time.

In terms of drive designs, those with separate gear reducers tend to be somewhat more robust than unitary gear motor drives. Chain drives, which are found on a few models, need to be lubricated regularly and the chain should be protected from debris and other impediments.

Installing an Oil Skimmer

The biggest installation issues are the amount of space required and cost. With regards to space, there are two areas that need to be considered: mounting area and water surface area. Installation of a suction skimmer also may involve sensors and a control box.

Moving medium skimmers require some sort of rigid mount on or near the reservoir. Some require the drilling of holes into the tank, which can be costly, depending on the reservoir design. Because of drive design, drum types tend to require more elaborate mounting methods and space. Belt, disk, tube and mop drive units consume a moderate amount of space.

An advantage of some belt skimmer drives is the use of a flat surface mount or bracket, neither of which require tank modifications. Mounting stands, brackets and adapters help make skimmer installations easier and faster.

Portability is a plus in some applications. For example, in plants and mobile equipment service shops, a portable skimmer can sometimes service both a parts washer and a drain water retention sump.

Belt and disk type skimmers tend to be the best designs for portability, and can be made small enough to weigh only a few pounds.

As most hydrocarbons spread fairly quickly over the top of water, it is not necessary to use more of the surface than the skimmer medium contact area. However, a skimmer’s design may actually take up more of the surface than the minimum required. A drum skimmer may require up to five square feet depending on drum size.

A tube skimmer requires four to five square feet due to the tube snaking out over the surface of the liquid. Unless a mop medium is constrained by a tail pulley, it moves around and takes up surface real estate. This is particularly true when there is turbulence.

Disk skimmers generally require from one-half to one square foot of liquid area.

Belt skimmers require from a few square inches to about one square foot, which is determined by the belt width and diameter of the tail pulley.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Abanaki Model 8 Belt Skimmer in Operation

Choosing an oil skimmer best suited for your application will maximize oil removal while minimizing capital outlay and oil skimming operation costs. In selecting an oil skimmer is to know what you need or expect your removal capacity to be.

Capacity should be based on the maximum amount of oil to be removed within the shortest available time. For instance, total oil influx may be 200 gallons in a 24 hour period, which averages about 8.3 gallons per hour. But if most of it comes during a single eight hour plant shift, you will probably need a removal rate that is three times as high, especially if you are trying to prevent an unwanted 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.

Rating

Oil skimmers usually have an oil removal rate expressed in gallons per hour. The rate varies with oil viscosity, so Abanaki rates skimmers using SAE 30 weight motor oil at 65°F (18°C). When specifying removal capacity, it is better to err on the high side to allow for peaks in the oil influx.

Water Content

All oil skimmers pick up some water with the oil they remove. Some designs, particularly suction skimmers, pick up more water than others. 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. An Oil Concentrator® or decanter installed at the oil skimmer discharge port provides secondary oil/ water separation that can reduce water content to nearly zero.

Residual Oil

An oil skimmer continues to remove oils as long as they are present. Depending on oil influx rate and the oil skimmer's removal rate, residual oil in the water may be as low as a few parts per million. When residual oil reaches this level and further reduction is required, it may be more practical to use a secondary removal method following skimming, such as membrane filtration.

Portability

Oil skimmer portability is a plus in some applications. For example, in plants, mobile equipment service shops, and at remediation sites, a portable oil skimmer can sometimes service multiple machines, sumps, or wells.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

HOW TO TELL WHAT SKIMMER YOU NEED FOR YOUR MACHINE COOLANT

Have you ever looked at your coolant and wondered what type skimmer would work best in your machine sump? In this video, we talk about what oil skimmer works well in various coolant applications.

How exactly does an oil skimmer work? Do I have to place the skimmer directly where the oil is collecting?

An oil skimmer is a device that uses a belt, tube, or disk placed directly into the product containing oil. The belt, tube, or disk attracts the oil by breaking the surface tension of the water and then runs back to the machine to be wiped clean. If your skimmer is sized right, it will be able to pull the free-floating oil from anywhere in the tank or pit. Oil skimmers should be purchased more by size than by the volume of oil to ensure you are able to skim from the whole surface area.

How can I fix the slipping belt on belt skimmer?

Check to make sure there are no obstructions on the belt as it passes through the wipers. Check to make sure that the tail pulley (bottom roller) turns freely and is free from obstruction. Sometimes the coolant/oil combination in the application can be extremely slippery, making the belt slip. Try adding a ½˝ spacer between the stabilizer bar spring and the mounting base plate to provide extra tension on the belt. The added resistance should keep the belt from slipping.

How many parts per million (ppm) will the oil skimmer get my oil level down to?

Abanaki oil skimmers have satisfied EPA requirements of leaving less than 5 ppm of oil in water. In addition, with an Abanaki Oil Concentrator, the oil skimmer will pick up less than 1% water with the removed product.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

What is the best belt for oil skimmer?

There is a great deal of variance in applications where belt skimmers are present. Figuring out what would be the best belt material for your belt skimmer will depend on a few factors. For the most part, belts pick up the oil in the same fashion so the big difference is finding what will give you the longest operating life. 

The two factors that play into your belt choice the most is your combination of temperature and pH levels. This will typically dictate the use of a steel, elastomer, or polymer belt. When rust inhibitors are present in your application, you will want to stay away from steel because the belt can get coated in the inhibitors reducing the pick-up rate. It is best to call with details of the application and ask your Abanaki representative what will work best with your belt skimmer.

Is it too much water in your oil skimmers?

Sometimes there are situations where your oil skimmer will collect water. If you are running your skimmer 24/7 and the tank or pit runs out of oil, your skimmer will pick up whatever is remaining in the tank, and most of the time that will be water or coolant.

There is a way to prevent this and that is by utilizing an oil water separator(concentrator) in conjunction with your oil skimmer. The oil water concentrator attaches to the skimmer and helps in further separating the water/coolant from your oil. This unit is placed on the back of the skimmer. The skimmed material is drained into the concentrator and then it separates the water from oil. You can then drain the water back into the tank or well through one hose, and the oil drains from another.

Is there a test that I can do to see if a skimmer will pick up my oil?

Yes. The simplest way to test if your oils will be picked up by the skimmer is to stick a PVC pipe or steel rule in the water where the contaminated oil is located and pull it out. The oil that sticks to the pipe or rule indicates that an Abanaki oil skimmer will work in the application.

Call 440-543-7400 to speak with one of our technical sales representatives to specify the proper oil skimmer for your particular application.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Learn how Abanaki oil skimmers help you save by "taking just a little off the top."

Selecting and sizing your next oil skimmer correctly is important – the wrong decision can cost your facility thousands over the long term. 

Watch this webinar.

There are several things to consider when choosing a belt or tube material for your oil skimmer. Some plastics will not stand up to heat or strong chemicals. Certain metal belts will not skim coolants effectively. Smooth belts do no pick up floating emulsified oils. Specific plastic belts do not last in heated applications, while other types of plastic belts will.

What is the maximum amount of oil to be removed, and the shortest period of time available to do it? Capacity should be based on the maximum amount of oil to be removed within the shortest available time. For instance, total oil influx may be 200 gallons in a 24-hour period, which averages about 8.3 gallons per hour. But if most of it comes during a single 8-hour plant shift, you will probably need a removal rate that is three times as high, especially if you are trying to prevent an unwanted 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.

Oil Skimmer Belt, Tube, and Disk type

Capacity is not affected by length. Choose a length that: assures contact with the liquid at its lowest level; allows easy mounting of the oil skimmer where oil discharge is convenient; and has good access for routine service. Abanaki’s ability to supply oil skimmers with long belts, and lift skimmed oil well over 100 feet with no loss in capacity or efficiency, is important to many users.

The chart below indicates the appropriate belt for the most common applications. The guidelines below are general, actual performance of the belts will depend on the variables of each application. Heat, for example, increases a belt’s sensitivity to pH levels.

Wiper Blades

Abanaki offers different materials to suit a variety of operating conditions. The standard is Nitrile (also known as Buna-N), which is appropriate for about 80% of all applications. Optional materials are designed for applications with harsh operating conditions. The materials include: CRV (very high chemical resistance), ceramic hybrid (excellent lubricity and moderate chemical resistance), and stainless steel wipers.

What type of wiper blades are the best? The charts below illustrate characteristics of each material.

Motor Types

All Abanaki oil skimmers are designed with standard, industrially rated, continuous duty motors and fully enclosed speed reducing drives. Most of these oil skimmers can be specified with the following motor options:

• Any standard or exceptional electrical requirement
• Explosion proof
• Drip proof
• Tropicalized
• Dirty duty
• Food service
• Wash down duty
• DC motors
• ATEX/European motors

What type of motor do you require? The following are the standard motors available with Abanaki belt oil skimmers:

Optional Components

Abanaki offers various options to adapt to different applications. Some of the most common options are listed below:

• Mounting Stands
• Concentrators
• Heated Decanter
• Yokes and Chains
• Heater Hood for Outdoor
• Belt Retainer

Understanding and choosing the appropriate oil skimmers components can be difficult. If you are faced with an unusual requirement, contact us about the availability of special motors, controls and drive components.

To learn more about oil skimmers, please contact our experts at 440-543-7400 or visit our website: www.abanaki.com

Abanaki Model 8 Belt Skimmer in Operation