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| CYLINDRICAL OIL-WATER SEPARATORS |
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OWS / POWS
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FEATURES
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| McTighe Industries cylindrical
oil-water separators are designed to separate free oils and grease
from wastewater. Standard sizes range from 350 gallons to 30,000
gallons with flowrates from 45 to 4405 gpm. Larger engineered systems
are available. Due to the inherent strength of the cylindrical design,
these separators are well suited for buried installations. We also
offer heavy duty saddle and skid mounting for installations above
grade or in a vault. There are two main cylindrical separator configurations
McTighe offers - our standard separator model OWS
- and our Petro Pak* equipped separator
model POWS. |
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| Both separators
include highly efficient corrugated plates to coalesce floating
oils and grease. The POWS 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 side
of the separator. |
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| * The OWS model separator has been
designed and proven to produce 15 part
per million or less free oil in the effluent under normal
operating conditions.* |
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| * The POWS model separator has
been designed and proven to produce 10
part per million or less free oil in the effluent under
normal operating conditions.* |
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OPERATION
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| 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 separator behind the sludge
baffle. The following provides a basic description of the flow path
through the standard McTighe cylindrical oil-water separator. |
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| 1. Inlet |
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| 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. |
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| 2. Distribution Chamber and
Corrugated Plate Separator |
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| The distribution chamber reduces
the separator velocity and spreads out the flow in an even manner
across the cross sectional area of the separator. As influent passes
over the inlet Corrugated Plate Separator, the tumbling action of
the oil-laden water passing over the corrugations causes the oil
droplets to separate from the wastewater stream. The benefits of
the Corrugated Plate Separator have been established for decades.
The concept of passing floatable industrial liquids over a single,
corrugated plate at a perpendicular position to the inlet flow is
known as the Buffalo-Morse Principle. |
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| An additional
benefit provided by this plate is that it allows sludge or heavy
solids to break away from oil droplets and to settle to the bottom
of the McTighe separator. The interior hydraulics of the separator
carry the solids downstream where they collect behind our sludge
baffle. |
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| 3. Corrugated Parallel Plate
Separator |
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| 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 corrugate parallel plates have also 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 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. |
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| The patented McTighe Industries
cylindrical separator incorporates an inclined arrangement of corrugated
plates stacked upwards at a 45o angle (30o angle for 350 and 550
gallon separators). The inclined plates allow solids and sediment
to drop out of the plates to prevent build-up and possible plugging
problems. The McTighe corrugated plates are also adequately spaced
(Do we want to add plate spacing - 2.75" - or "greater
than 2.5""?) to prevent plugging from other objects such
as rags, trash, grass clippings, etc. There is an open area beneath
our Corrugated Parallel Plate pack that allows sediment to pass
downstream of the plates and accumulate behind a sludge baffle. |
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| 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 increase
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. |
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| 4. Separation Chamber |
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| In the McTighe separator, the corrugated
plates are at the inlet end of the separator to maximize the distance
between the plates and the outlet pipe. 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 volumes
requiring treatment. |
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| 5. McTighe Petro Pak* Coalescer
on POWS Models Only |
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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.
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6. Outlet
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| 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. |
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* NOTE:
Normal Operating Conditions are as
follows
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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 40 degrees F to 140 degrees
F. Contact McTighe Industries on applications where influent
requirements exceed the stated limits.
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| These are the standard
operations, separators may be specifically modified to meet special
applications. See Special Configurations for additional separator
layouts. |
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| 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 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.
Question Regarding deviations from originally intended use of McTighe
Industries Oil-Water Separators should be directed to: |
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| ACCESS |
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| Standard OWS
units are provided with one (1) UL approved 30" Interior Diameter
round access manway (24" ID for OWS-350 and OWS-550) that includes
extension, cover, gasket and bolts . We can provide interior ladders,
quick release clamps in lieu of bolts and other diameters (18",
36", and 42" for example.) |
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| Standard POWS
units are provided with one (1) UL approved 24" Interior Diameter
round access manway and one (1) UL approve rectangular access manway.
(Separator models POWS-350 and POWS-550 have one (1) 24" square
manway and one (1) manway is also available on separator models
through POWS-3000.) Manway(s) includes extension, cover, gasket
and bolts. See separator drawing for rectangular manway dimensions.
Interior ladders, quick release clamps in lieu of bolts and other
sizes are available. |
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| DRAWING DESCRIPTION |
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| McTighe provides professional
CAD blueprint drawings for every oil-water separator order we process.
The CAD drawings include all accessory information that is provided
with the separator at the time of purchase. |
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| The Catalog cut drawings
for our OWS (drawing No. OWS-1-0 dated May 20, 1997) and POWS (drawing
No. POWS-1-0 dated May 22, 1997) model oil-water separators provide
details on our standard oil-water separator configurations. The
flowrates, oil storage volumes and dimensions can be modified to
match site and performance conditions. |
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| See Special Configurations
(Section 2), Above Grade Installation (Section 2), 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. |
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