FEATURES

McTighe Industries rectangular oil-water separators are designed to separate free oils and grease from wastewater. Standard sizes range from 115 to 1440 gallons with flowrates from 20 to 150 gpm. Larger engineered systems are available. These separators are designed for installations above grade or below grade in a vault. There are two main rectangular separator configurations McTighe offers - our standard separator model CO - and our Petro Pak™* equipped separator model PCO.

Both separators include highly efficient corrugated plates to coalesce floating oils and grease. The PCO models include our enhanced Petro Pak™* coalescer to aid in removing small oil droplets that do not have enough buoyancy to be captured before entering the discharge end of the separator.

* The CO model separator has been designed and proven to produce 15 parts per million or less free oil in the effluent under normal operating conditions.*

* The PCO model separator has been designed and proven to produce 10 parts per million or less free oil in the effluent under normal operating conditions.*

OPERATION

Separation within the unit is perpetual on a last-in, last-out basis. As oily influent enters the oil-water separator, a corresponding amount of separated effluent is automatically discharged through the effluent pipe. Light oils will accumulate in the top of the separator and fluid or materials heavier than water will collect in the bottom of the 1st chamber. The following provides a basic description of the flow path through the three chambers of the standard McTighe rectangular oil-water separator.

1. Inlet and Interceptor/Distribution Chamber

The invert of the inlet pipe is above the static operating surface level of the separator to provide positive drainage of the inlet pipe. The inlet pipe is designed to conform to the flow capacity of the separator.

The Interceptor/Distribution chamber reduces the separator velocity and spreads the flow out in an even manner across the cross sectional area of the separator. Large free oil droplets collect at the operating surface of the Interceptor/Distribution chamber and are transferred through diffusion pipes into the Separating chamber.

Sediments or heavy solids fall to the bottom of the Interceptor/Distribution chamber as sludge for periodic removal.

2. Corrugated Parallel Plate Separator

The Corrugated Parallel Plate Separator within the McTighe oil-water separator vastly improves the efficiency of separation by enlarging the effective separation surface area through the use of multiple parallel corrugated plates.

The advantages of corrugated parallel plates have been known for decades thanks to initial research in the 1960's by Royal Dutch Shell Oil Company and Pielkenrod-Vinitex of the Netherlands. The main difference between McTighe and other companies that use corrugated plates is that we use a combination of separation technologies and provide a plate arrangement that is not only high performance, but is also maintenance friendly.

The McTighe Industries rectangular separator incorporates an inclined arrangement of corrugated plates stacked upwards at a 30° angle in the direction of flow spaced equal distance apart to prevent build-up and possible plugging problems.

The McTighe Corrugated Parallel Plate arrangement greatly reduces the distance an oil droplet has to rise for effective removal. Also, the sinusoidal flow path created by the plates creates oil droplet collisions resulting in increased oil droplet size. Under laminar flow conditions, buoyancy forces cause the oil droplets to rise and coalesce into sheets of oil on the underside of the plates where they creep up the surface and eventually break loose in the form of large oil globules. The rest of the separation chamber allows the oil globules to rapidly rise to the surface creating an oil layer.

3. Separation Chamber

In the McTighe separator, the separation chamber is designed to provide adequate volume for the coalesced oil droplets to reach the surface for effective separation. The separation chamber size increases in relation to the increasing wastewater volume requiring treatment.

4. McTighe Petro Pak* Coalescer on PCO Models Only

The McTighe Petro Pak* is designed to remove small oil droplets down to 20 microns in size that do not have sufficient buoyancy to reach the surface of the separator before entering the discharge region. The Petro Pak* coalescer in the McTighe separator is placed as far away from the corrugated plates as possible. This prevents the coalescer from experiencing a high oil loading from oil droplets that are large enough to separate before reaching the Petro Pak™*.

See our Petro Pak™ description sheet for more information.

NOTE: The CO models include steel channels and access for the possible addition of our Petro Pak* coalescer in the future.

6. Outlet Chamber

The discharge pipe opening is located at the furthest point distant from the inlet at the most quiescent zone of the separator. The invert of the outlet pipe establishes the static surface level of the separator. The outlet pipe is designed to conform to the flow capacity of the separator.

These are the standard operations; separators may be specifically modified to meet special applications. See Special Configurations for additional separator layouts.

McTighe Industries Oil-Water Separators are engineered and sized for specific rates of flow. Influent flow rates in excess of the units stated maximum gallons per minute flow rate will result in decreased separator efficiency. Also, each McTighe separator is designed and built to separate a particular type of influent as outlined at the time of purchase. The introduction of contaminated products not specified at the time of purchase may result in decreased separator efficiency. It is especially important that detergents are not allowed into the separator. Detergent emulsified oils must be chemically pretreated before entering the separator. Centrifugal or high speed pumps should not be used on the influent as they will create mechanically emulsified oils of less than 20 microns in size that will not readily separate. Questions regarding deviations from originally intended use of McTighe Industries Oil-Water Separators should be directed to:
McTighe Industries, 3405 S. Westport Ave., Sioux Falls, SD 57106. Phone: 888-776-0581 Fax: 605-362-3414

ACCESS

Access to all chambers of the separator, dependent on design requirements, is through two (2) 3" clean-out ports. In the event that major maintenance is required, the entire gasketed steel cover of the separator can be unbolted and removed. A separate gasketed steel cover is provided for direct access to the Petro Pak* and/or the steel channels for the Pak.

DRAWING DESCRIPTION

McTighe provides professional CAD blueprint drawings for every oil-water separator order we process. The CAD drawings include information on all accessories that are provided with the separator at the time of purchase.

The Catalog cut drawings for our CO (Drawing No. CO-1-0 dated May 28, 1997) and PCO (Drawing No. PCO-1-0 dated May 30, 1997) model oil-water separators provide details on our standard oil-water separator configurations. The flowrate, oil storage volume and dimensions can be modified to match site and performance conditions.

See Special Configurations (Section 3), Above Grade Installation (Section 3), Oil Removal Options (Section 4), and Accessory Information (Section 6) of this catalog for additional details on separator layouts and controls. McTighe can provide tailored CAD drawings and disks to specifying engineers and architects.

* Normal Operating Conditions.

The catalog flow ratings are based upon influents containing oils of 0.90 or lighter specific gravity, up to 20% (200,000 ppm) oil content in the water and temperatures of 40o F to 140o F. Contact McTighe Industries on applications where the influent requirements exceed the stated limits.