2. 1/15/2019
OIL Water Separation
Can-Am has been providing Separation Technology to a variety of industries for over 40 years
We are proud to be the Canadian representatives of Highland Tank
We specialize in custom solutions for Hydro Power Generators
Can-Am Instruments

3. GENERAL DISCUSSION AND THEORY OF OIL-WATER SEPARATION:
In 1845, an English mathematician named George Stokes first described the
physical relationship that governs the settling of solid particles in a liquid (Stokes’s Law, 1845). This same relationship also governs the rising of light liquid droplets (oil) within a different, heavier liquid (water).
Assumptions Stokes made in his calculation were:
1) Particles are spherical
2) Particles are the same size
3) Flow is laminar, both horizontally and vertically. Laminar flow in this context
means flowing gently, smoothly, and without turbulence.

4. How this applies to OWS
Separators operate on the principle of density. Materials lighter than water (such as oils) will float while materials heavier than water (such as grit and sediment)
will sink. Water acts as the separating
layer between the light and heavy layers.

5. The rise rate of oil droplets is also governed by Stokes's Law
The rise rate of oil droplets is also governed by Stokes's Law. If the droplet
size, specific gravity, and viscosity of the continuous liquid are known, the rise
rate may be calculated.
To calculate the size of an empty vessel gravity separator, it is first necessary
to calculate by the use of Stokes's Law the rise velocity of the oil droplets. The
size of the separator is then calculated by considering the path of a droplet
entering at the bottom of one end of the separator and exiting from the other
end of the separator. Sufficient volume (residence time) must be provided in
the separator so that an oil droplet entering the separator at the bottom of the
inlet end of the separator has time to rise to the surface before the water
carrying the droplet exits the opposite end of the separator.

6. When the droplets coalesce, they do not form flocs as the solid particles can,
but coalesce into larger droplets. Interfacial tension (sometimes referred to as
surface tension) of the liquid tends to make the droplets assume spherical
shapes since this is the smallest possible shape for a given mass. This is
convenient for a separator designer because it is required by Stokes’s Law.
It is very difficult to be sure of maintaining laminar flow (as required by Stokes’s
Law) in large empty-tank separators because of the turbulence problem. For this reason, coalescing modules are used to ensure laminar flow
and therefore a system that behaves according to Stokes’s Law.

7. Oil Water Separator Animation

8. A properly designed plate coalescer will:
• Enhance the separation of oil from water through added horizontal surface area and by creating less turbulent flow.
•Amplify the difference in densities by providing longer path for the fluid to travel.
• Minimize the distance an oil droplet needs to travel to find another oil droplet
• Promote coalescence; as the oil droplets collect they coalesce with other droplets and the larger droplets rise more rapidly to the water’s surface.

9. Aboveground Oil/Water Separators
Rectangular HT/HTC:

10. CORELLA™ What is CORELLA™?
CORELLA™ is a removable, inclined parallel flat/corrugated plate coalescer with removable plates.

11. design performs better
New CORELLA™
“self-cleaning”
design performs better
than traditional
plate coalescers.

12. SELF-CLEANING PLATE PACK
CORELLA®
SELF-CLEANING PLATE PACK

13. IMPINGEMENT COALESCER
PETRO-SCREEN
IMPINGEMENT COALESCER

14. Start-Up
Confirm proper venting in accordance with applicable plumbing and safety codes.
Wiring complies with all applicable electrical and fire codes.
Service personnel must comply with all established MOL codes and regulations.
All electrical equipment, connections and wiring must be protected from submergence and infiltration of water.

15. Start-Up Fill the OWS with clean, fresh water.-> Dec 3rd
OWS is full when water drains out of the Outlet.
To ensure that no blockage exists, allow water to flow through the facility drain which leads to the OWS Inlet.
Check the Outlet Pipe to make sure that water is flowing through the OWS.
Check the Inlet Pipe and facility’s drain for water backup.

16. General OWS Cleaning Procedures
If not properly maintained, the OWS may malfunction.
Important: It is recommended that the OWS be cleaned as needed or at least inspected once a year.
Keep inspection and maintenance logs and have them available for ready reference.

17. Maintenance
For optimum performance, maintenance is required as needed or at least:
When Bottom sludge in tank is X" deep;
X is determined by the size of the OWS
The effluent exhibits an oil sheen or contains high contaminant levels.
When there has been a spill
When there has been a High Oil Alarm
When there has been a leak alarm

18. Maintenance
WARNING: Never enter an OWS or enclosed space, under any condition, without proper training and equipment.

19. Maintenance
Be sure to inspect and replace manway gaskets as necessary when the OWS is shutdown for maintenance.
The coalescer plates and packs can be removed for cleaning or can be cleaned from above using a hot-water pressure wash with extension wand.
Mechanical lifting is required to remove the Petro Screen coalescer packs in larger OWS.

20. Maintenance OWS are designed for long-term, trouble-free operation.
Periodic inspection of upstream trench drains, sand interceptors, and traps is required
Inspect inside of the OWS for sand, trash, sludge and oil build-up
Sample effluent for oils and other contaminants in accordance with local codes and permits

21. Maintenance
Initially inspect OWS after a heavy rainfall to check for signs of oil.
If the OWS has no oil buildup within the year and only bottom sludge has built up it may be sufficient to vacuum the sludge from the sediment chamber and refill OWS with clean water.
Power down the Control Panel to prevent alarms

22. Sludge Cleanout with a full OWS
If the object is to remove sludge only without emptying the OWS then verify the depth of sludge with a gauge stick
Place gauge stick into the OWS through the 3” FNPT Cleanout in the 2nd cover plate from the inlet.
Slowly lower the gauge stick until it comes into contact with the sludge blanket. Mark the stick. Push the stick downward until it comes into contact with the Striker Plate on the OWS bottom. Mark the stick. The sludge depth is the difference between the two measurements.
Sludge removal is recommended if the depth is 12” or more

23. Sludge Removal Procedures (for full OWS)
Place a 3" diameter or smaller suction hose inside the OWS through the cleanout or remove the cover plate (2nd from the inlet)
Lower hose to exact sludge/water interface location.
Suction out the sludge while slowly lowering the suction hose nozzle until it comes into contact with the Striker Plate on the OWS bottom.
Refill with clean water.
Power up the Control Panel

24. Oil Removal Procedures
Close the Upstream and Downstream Valves
Oil should only be removed during non-flow conditions to ensure pure oil draw-off.
If only a small amount or ‘sheen’ of oil is evident then suitable sorbent material can be used to remove the oil.
If the High oil alarm has been activated you can use the Oil pump out pipe to remove the oil.
Open the Upstream and Downstream Valves
Refill OWS with clean water

25. Major Oil Spill Response Procedures
Important: A major oil spill is a spill which exceeds the normal oil storage capacity of the OWS. High-High Oil alarm
In the event of a major spill, notify proper authorities as required by federal, provincial, and local laws.
After a major oil spill, the OWS should be emptied, cleaned, and refilled with clean water.

26. OWS Cleaning Procedures
Power down the Control panel to prevent alarms
Inlet and effluent pipe valves should be closed.
All oil must be removed from the OWS.
Using a Vacuum Truck start sucking the oil at the surface DO NOT Plunge the Vacuum hose to the bottom or middle of the tank.
Continue removing the oil until water only remains
Any oil recovered from the OWS should be recycled or disposed of in accordance with federal, provincial, and local codes and regulations.

27. Sediment Chamber Cleaning
Remove manway cover to the Sediment Chamber.
Remove remaining contents of OWS.
Remove the accumulated waste with a suction hose.

28. Sediment Chamber Cleaning
Direct a high pressure hose downward to loosen any caked oily solids on OWS sides and bottom.
Attach spray nozzle wand extension to the high pressure hose.
Direct spray downward and toward the velocity head diffusion baffle
loosen up any caked oily solids that may have accumulated on inlet head.
Direct the spray to the OWS wall sides, top and bottom.
Remove the slurry with the suction hose.

29. Oil Water Separator Chamber Cleaning
Remove the Oil Level Sensor.
Clean the Oil Level Sensor if dirty.
Use mineral spirits to remove accumulated oil, grease, or sludge.
Check the Oil Level Sensor
Place the Oil Level Sensor in a safe area to prevent damage.

30. Oil Water Separator Chamber Cleaning
Remove manway cover over the Oil Water Separation Chamber.
Remove the accumulated waste with a suction hose.

31. Oil Water Separator Chamber Cleaning
Flush the Parallel Corrugated Plate Coalescer Corella™ from the outlet side to direct debris to Sediment Chamber.
Direct the spray to the OWS wall sides, top and bottom.
Rotate the nozzle sufficiently and often so that all areas are reached with the spray.
Suction out the slurry

32. PETRO-SCREEN™ Coalescer Cleaning
Petro Screens CAN be cleaned in place or removed for cleaning.
Mechanical lifting equipment is required to remove the Petro Screens in this unit.
Petro Screens at Lower Notch are stacked horizontally and each has two lifting lugs
Attach a hook and chain (or strap) to each Lifting Lug on the Petro Screen and remove the pack by lifting vertically.
Continue until Petro Screens have been removed and are above grade.

33. PETRO-SCREEN™ Coalescer Cleaning
Place Petro Screens on oil absorbent blanket or sheet plastic.
The packs should be moved to a convenient location upstream of the separator and washed to remove any gummy deposits.
Flush the coalescer packs from both sides.
Let coalescer packs stand and dry.

34. PETRO-SCREEN™ Coalescer Cleaning
Visually inspect the OWS interior and components for any damage.
If any visual damage exists, contact Highland Tank or Can-Am Instruments for further instructions.
Reinstall the coalescer packs.
The coalescer packs must be installed sitting on top of the bottom steel channel supports.

35. PETRO-SCREEN™ Coalescer Cleaning
Improper installation will result in separator malfunction.
Re-attach the cover.
Install the Oil Level Sensor
Refer to OWS Start-Up Instructions for proper refilling and restarting procedures.
Power up the control panel

36. Petro Screen Coalescers
The Petro Screens are NOT Filters
They are designed to attract, coalesce and ‘wick’ to the surface small oil globules that have not coalesced on the Corella plates
Typically by the time the Petro Screens need to be cleaned the entire separator should be emptied and cleaned as well.

37. Proactive Maintenance Cycle
For the first year the separator should be inspected regularly to establish if there is any build up of oil or sludge/sediment
Inspection should also be carried out after a major storm or if a spill event is suspected.
A log of the findings will establish if there is a requirement for increased inspections

38. Questions?

40. Technical assistance 1-800-215-4469 Ext 225
Fax:
Can-Am Instruments Ltd.
2851 Brighton Rd. Oakville, ON L6H 6C9