U.S. patent application number 09/925898 was filed with the patent office on 2002-03-07 for method and apparatus for removing oil from water including monitoring of adsorbent saturation.
This patent application is currently assigned to AMCOL International Corporation. Invention is credited to Berger, Michael A., Darlington, Jerald W. JR., Johnson, Michael R., Occhipinti, John, Robichaux, Elmo, Smith, Jeffrey J..
Application Number | 20020027106 09/925898 |
Document ID | / |
Family ID | 24836320 |
Filed Date | 2002-03-07 |
United States Patent
Application |
20020027106 |
Kind Code |
A1 |
Smith, Jeffrey J. ; et
al. |
March 7, 2002 |
Method and apparatus for removing oil from water including
monitoring of adsorbent saturation
Abstract
Apparatus in fluid communication with a water leg portion of a
hydrocarbon-contaminated water, e.g., a water leg portion of an
offshore drilling or production platform sump tank for conveying
water, separated from oil, into contact with organophilic media
canisters such that the hydrocarbons and other organic materials
commingled with the sump tank water will be adsorbed onto the
organophilic media and detected by the embedded probe in selected
canisters. The canisters are provided in a plurality of stacks and
are in fluid communication with a header disposed at the bottom of
the vessel housing the various stacks of canisters. Solids that do
not pass through the canisters are accumulated at the bottom of the
vessel and easily drained through a drain port. The water will pass
through the media and will be conveyed back to the ocean water
without contamination. At some point in time, the organophilic
media will become "spent" and at a certain "spent level", the
saturated condition of the organomedia will be electronically
detected by the embedded probe and alarm/control panel. The alarm
indicates that the "spent" organophilic media should be replaced
with fresh media or the spent media regenerated.
Inventors: |
Smith, Jeffrey J.; (New
Orleans, LA) ; Darlington, Jerald W. JR.; (Marengo,
IL) ; Johnson, Michael R.; (Mandeville, LA) ;
Occhipinti, John; (Mandeville, LA) ; Robichaux,
Elmo; (Cut Off, LA) ; Berger, Michael A.; (New
Orleans, LA) |
Correspondence
Address: |
MARSHALL, O'TOOLE, GERSTEIN, MURRAY & BORUN
6300 SEARS TOWER
233 SOUTH WACKER DRIVE
CHICAGO
IL
60606-6402
US
|
Assignee: |
AMCOL International
Corporation
|
Family ID: |
24836320 |
Appl. No.: |
09/925898 |
Filed: |
August 9, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09925898 |
Aug 9, 2001 |
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09706130 |
Nov 3, 2000 |
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09706130 |
Nov 3, 2000 |
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09352457 |
Jul 13, 1999 |
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6235201 |
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09352457 |
Jul 13, 1999 |
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09081976 |
May 14, 1998 |
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5935444 |
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Current U.S.
Class: |
210/691 |
Current CPC
Class: |
B01D 17/0202 20130101;
B01D 2201/0476 20130101; B01D 17/0214 20130101; B01D 29/114
20130101; B01D 35/143 20130101; B01D 29/54 20130101; C02F 1/681
20130101; B01D 29/52 20130101; Y10S 210/924 20130101; C02F 1/281
20130101; C02F 2101/32 20130101 |
Class at
Publication: |
210/691 |
International
Class: |
C02F 001/40 |
Claims
What is claimed is:
1. An apparatus for separating hydrocarbons from a liquid
containing water and hydrocarbons, the apparatus comprising: a
vessel connected to an inlet and an outlet; the inlet for conveying
the hydrocarbons and water into the vessel; the vessel further
comprising at least one permeable conduit, the conduit passing
through at least one cylindrical cartridge; the cartridge
comprising a permeable outer cover and a permeable inner tube, the
cartridge containing an organophilic media between the outer cover
and the inner tube, the liquid flowing radially inwardly through
the outer cover, through the media and through inner tube before
flowing into the conduit, the media providing intimate contact with
the liquid and adsorption of the hydrocarbon contaminant on the
media; the conduit being connected to a header and extending upward
from the header, the header being disposed inside the vessel and
being detachably connected to the outlet.
2. The apparatus of claim 1, wherein at least one of the cartridges
comprises means for monitoring the degree of remaining adsorption
capacity of the organophilic media.
3. The apparatus of claim 1, wherein at least one of the cartridges
comprises a probe comprising two spaced apart elements for
monitoring a property of the liquid flowing through the media; and
the elements being aligned parallel to the radially inwardly flow
of the liquid.
4. The apparatus of claim 1, wherein the vessel is secured to an
oil well platform support structure.
5. The apparatus of claim 1, wherein the vessel comprises an outer
fluid-impermeable housing, a plurality of permeable conduits
connected to the header and extending upward from the header and
within the housing, each conduit passing through at least two
cartridges with one of said cartridges stacked on top of the other
of said cartridges.
6. The apparatus of claim 2, further including means for providing
a visual or audible signal when the remaining hydrocarbon
adsorbance capacity, as measured by the property, reaches a
predetermined minimum value.
7. The apparatus of claim 1, wherein the header is detachably
connected to the liquid outlet by a plurality of removable
fasteners.
8. The apparatus of claim 1, wherein the vessel further comprises a
drain outlet, the drain outlet being disposed below the header, the
drain outlet for removing accumulated solids from the vessel.
9. A method of manufacturing an apparatus for separating
hydrocarbons from a liquid containing water and hydrocarbons, the
method comprising: providing a hollow cylinder having an open top
end, an open bottom end and an inside surface; welding a bottom
structure to the bottom end of the cylinder to enclose the bottom
end of the cylinder, the bottom structure comprising an inside
surface and a drain outlet with a valve disposed exterior to the
bottom structure for opening and closing the drain outlet, the
bottom structure further comprising a treated water outlet, the
treated water outlet comprising an inner end disposed inside the
bottom structure; coating the inside surface of the bottom
structure and the inside surface of the cylinder with a protective
coating; connecting a header to the inner end of the treated water
outlet; connecting at least one permeable conduit to the header;
and placing at least one cartridge on one of the conduits, the
cartridge comprising a permeable outer cover and a permeable inner
tube, the cartridge containing an organophilic media between the
outer cover and the inner tube, the permeable conduit extending
through the inner tube, the media providing intimate contact with
the liquid and adsorption of the hydrocarbon on the media;
attaching a removable top structure to the top end of the
cylinder.
10. The method of claim 9, wherein at least one of the cartridges
comprises means for monitoring the degree of remaining adsorption
capacity of the organophilic media.
11. The method of claim 9, wherein at least one of the cartridges
comprises a probe comprising two spaced apart elements for
monitoring a property of the liquid flowing through the media; and
the elements being aligned parallel to the radially inwardly flow
of the liquid.
12. The apparatus of claim 9, further comprising a plurality of
permeable conduits connected to the header and extending upward
from the header and within the housing, each conduit passing
through at least two cartridges with one of said cartridges stacked
on top of the other of said cartridges.
13. The apparatus of claim 10, further including means for
providing a visual or audible signal when the remaining hydrocarbon
adsorbance capacity, as measured by the property, reaches a
predetermined minimum value.
14. The apparatus of claim 9, wherein the header is detachably
connected to the inner end of the liquid outlet by a plurality of
bolts.
15. A method of separating water from a liquid comprising a
combination of water and a hydrocarbon contaminant comprising:
flowing the liquid into a filtration vessel comprising an outlet, a
header connected to the outlet, and at least one permeable conduit
connected to the header, the conduit passing through a plurality of
cylindrical cartridges, each cylindrical cartridge comprising a
permeable outer cover and a permeable inner tube, the cartridge
containing an organophilic media between the outer cover and the
inner tube, the media providing intimate contact with the liquid
and adsorption of the hydrocarbon contaminant on the media;
providing a pressure within the filtration vessel of greater than
atmospheric; and flowing the separated water through the conduit,
through the header and out through the outlet.
16. The method of claim 15, wherein at least one of the cartridges
containing a probe comprising two spaced apart elements for
monitoring a property of the liquid flowing through the media, the
elements being aligned parallel to the radially inwardly flow of
the liquid, and the method further comprises: transmitting a signal
from one of the elements to the other of the elements to measure a
property of the liquid flowing between the elements; and monitoring
the property whereby a change in the property provides a measure of
remaining hydrocarbon adsorbance capacity of the media.
17. The method of claim 16, wherein the elements are conductive and
the signal is bipolar voltage at a given frequency and the property
is resistivity or conductivity.
18. The method of claim 16, further including means for providing a
visual or audible signal when the remaining hydrocarbon adsorbance
capacity reaches a predetermined minimum value.
19. The method of claim 15, wherein the filtration vessel comprises
a plurality of permeable conduits extending within the housing,
each of the conduits being connected to the header, the conduits
extending upward from the header and within the housing, each
conduit passing through at least one cartridge.
20. The method of claim 15, wherein the header is detachably
connected to the outlet.
21. The method of claim 16, wherein the elements comprise a pair of
metallic hollow circle tips each connected to a separate electrical
conducting wire for conducting an electrical signal to a visual or
an audible control panel to provide a visual or audible signal from
which a relative degree of remaining adsorbance capacity of
hydrocarbons in the organophilic media can be determined.
22. The method of claim 17, wherein the elements are made from
stainless steel.
23. The method of claim 17, wherein the elements are made from
Hasteloy/Incanel.
24. The method of claim 16, wherein the property of the
liquid/media that is monitored is selected from the group
consisting of the electrical conductance and the electrical
resistance thereof.
25. The method of claim 18, wherein a pressure within the vessel is
at least 5 psig.
26. The method of claim 21, wherein a signal proportional to the
electrical conductance or electrical resistance of sea water is
first determined as a base point in determining the change in
electrical conductance or electrical resistance necessary before
regeneration or replacement of the organophilic media is
effected.
27. The method of claim 15, further comprising: collecting the
hydrocarbon and water in a settling vessel and allowing the
hydrocarbon and water to settle to form a lower water layer and an
upper hydrocarbon layer, the lower water layer including a portion
of the hydrocarbon contaminant; and draining a portion of the water
layer from the settling vessel, prior to flowing the lower water
layer, including the hydrocarbon contaminant into the filtration
vessel.
28. The method of claim 27, wherein the property of the drained
portion of the water layer that is monitored is selected from the
group consisting of the electrical conductance and the electrical
resistance thereof.
29. A filter for separating hydrocarbon contaminant from a liquid
containing water and said hydrocarbon contaminant, the filter
comprising: an outer cylindrical permeable cover having a top edge
and a bottom edge; an inner cylindrical permeable tube having a top
edge and a bottom edge; an annular bottom connecting the bottom
edge of the outer cover to the bottom edge of the inner tube; an
annular top connecting the top edge of the outer cover to the top
edge of the inner tube; a probe connected to one of the annular top
or the annular bottom at a middle position between the inner tube
and the outer cover, the probe comprising two spaced apart
elements, each element being connected to a wire lead, each wire
lead being connected to a control panel; and the outer cover of
organophilic clay being disposed in a space defined by the inner
tube, the annular top and the annular bottom, the organophilic clay
surrounding the probe.
30. The filter of claim 29, wherein the elements each comprise a
metallic hollow circle.
31. The filter of claim 30, wherein the elements are made from
stainless steel.
32. The filter of claim 30, wherein the elements are made from
Hasteloy/Incanel.
33. The filter of claim 30, wherein the elements are aligned
parallel to a radius defined by a common axis of the outer cover
and the inner tube and which extends between the two elements.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application
Ser. No. 09/352,457, filed Jul. 13, 1999, still pending, which is a
continuation-in-part of application Ser. No. 09/081,976, filed May
14, 1998, now U.S. Pat. No. 5,935,444.
FIELD OF THE INVENTION
[0002] The present invention is directed to an apparatus and method
for removing oil, hydrocarbons and other organic materials from
water, particularly industrial waste waters, ship bilge pump
waters, produced water and rainwater collected on offshore oil
drilling and production platforms, by adsorption with an oil
adsorbent, while electronically monitoring the adsorbent with an
embedded probe to determine when the adsorbent needs replacement.
More particularly, the present invention is directed to an
apparatus and method that includes relatively crude, gravity
separation of oil from the water and then contacting the separated
water, containing a small amount of hydrocarbons, such as oil and
grease, with an organophilic clay to purify the water. During
adsorption of the hydrocarbons, the adsorbent is monitored, by the
probe, to determine when the absorbent is saturated and should be
replaced or regenerated. Further, the present invention is directed
towards an improved vessel for housing a plurality of cartridges of
the organophilic clay with a removable header for directing
filtered water out of the vessel.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0003] Offshore drilling and production platforms used for
recovering oil from subterranean formations disposed beneath ocean
water includes a number of structural support legs for supporting a
plurality of work deck areas at substantial heights above the water
level, e.g., disposed from 40 to 100 or more feet above sea level.
During the recovery of oil at one or more of these work deck areas,
oil, grease and other hydrocarbons are unavoidably spilled onto the
deck area(s) and it is not permissible to discard these
hydrocarbons into the ocean water. Such work deck areas or platform
surfaces are constructed to be fluid-impermeable in order to
contain the spilled hydrocarbons on the work deck areas. These
hydrocarbons, such as recovered oil, grease, surfactants and other
organic contaminants, are directed from the work deck or platform
areas, either by water washing or rainwater, into a sump pump
container or sump tank where the water and oil separate by gravity
so that the water can be removed from a lower portion of the sump
tank, for conveyance back to the ocean, and the oil can be pumped
from an upper portion of the sump tank into an oil recovery
container so that the oil is not returned to the ocean.
[0004] These contained deck areas on offshore structures collect a
significant amount of water during periods of high rainfall. The
rainwater and entrained hydrocarbons, particularly recovered oil,
grease and surfactants, are conveyed to the sump tank or collection
tank through a gravity drain system from each of the work deck
areas. These sump tanks rely on retention time as the primary
oil/water separation mechanism in order to skim the lighter density
hydrocarbons from a top of the sump tank so that the water can be
returned to the ocean.
[0005] The sump tanks presently used on offshore platforms suffer
from a number of major drawbacks which result in significant
amounts of hydrocarbons, particularly oil, paraffins, grease, and
refined hydrocarbons being returned to the ocean causing
significant ecological contamination. One major drawback of the
presently used sump tanks is that they are designed for a maximum
of about three inches of rainwater per hour. It has been found that
it is not uncommon to experience eight to ten inches of rainfall
per hour in areas such as the Gulf of Mexico. Another major
drawback of the sump tanks presently used on offshore drilling
platforms is that a tank containing a layer of oil disposed above a
layer of water will lose the water by evaporation over an extended
dry period and the oil layer, as a result, will coat the inside
surfaces of the sump tank. This phenomena is known in the art as
sheening. As a result of the sump tank sheening, water generated
from even a modest rain shower, after this drying period, carries
the oil through a water leg or drain portion of the sump tank as
the water initially washes lower inner surfaces of the sump tank,
thereby carrying the oil to the ocean.
[0006] Another water treatment problem associated with offshore oil
platforms is the treatment of the aqueous solutions used in acid
fracturing processes. Specifically, acidic solutions are commonly
pumped down under pressure to cause fractures in the oil producing
regions of the formation. As these acidic solutions are returned to
the surface, they are often contaminated with oil or hydrocarbons.
As discussed above with respect to rainwater, the hydrocarbons must
be removed from the solutions before the water is returned to the
ocean.
[0007] Another problem associated with all auxiliary equipment used
on oil platforms is the need for equipment to be designed in a
space efficient manner. Specifically, auxiliary equipment,
including water treatment equipment, must be designed in as space
efficient manner as possible because horizontal square footage on
an oil platform is scarce. Therefore, there is a need for water
treatment equipment that can treat water at a fast rate, but which
is also space efficient.
SUMMARY OF THE INVENTION
[0008] In accordance with one embodiment of the present invention,
an improved apparatus is provided for separating hydrocarbons from
a liquid containing water and hydrocarbons. The apparatus includes
an improved vessel design. The vessel includes an inlet for
conveying contaminated water into the vessel and an outlet for
transporting treated water out of the vessel. A removable header is
connected to the outlet and housed within the vessel. Permeable
conduits are connected to the header and extend upward therefrom.
Cartridges containing organophilic media for adsorbing hydrocarbons
are then stacked on the permeable conduits. Each cartridge includes
a permeable outer cover, a permeable inner tube with the
organophilic media disposed therebetween. A pressure drop is
provided between the vessel inlet and the vessel outlet, and
therefore between the vessel inlet and the permeable conduits. As a
result, the contaminated liquid flows radially inwardly through the
outer cover of the cartridges, through the media and through the
inner tube of the cartridge before flowing into the conduit.
Intimate contact between the media and the contaminated liquid
results in adsorption of the hydrocarbon contaminents on the media.
The header is detachably connected to the treated liquid outlet
thereby facilitating removal of the header for replacement or
servicing. Accumulated solids, which do not pass through the
cartridges, are conveniently collected at the bottom of the vessel
and can be flushed out through a drain valve.
[0009] In accordance with another aspect of the present invention,
an improved method of manufacturing such a vessel is provided. A
bottom structure is welded to an open bottom end of a hollow
cylinder. The bottom structure includes a drain outlet with a valve
disposed exterior to the bottom structure for opening and closing
the drain outlet. The bottom structure also includes a treated
liquid outlet with an inner end disposed inside the bottom
structure. The inside surfaces of the bottom structure and the
cylinder are coated with a protective coating to resist corrosion
in the presence of salt water and very acidic or basic solutions. A
header is connected to the inner end of the liquid outlet and
contained within the bottom structure of the vessel. Permeable
conduits are then connected to the header and extend upward through
the cylindrical section of the vessel. Cartridges, like those
described above, are placed singly or are stacked one on top of
another with the permeable conduits extending through the inner
tubes of the cylindrical cartridges. The improved method enables
the weld connecting the bottom structure to the bottom end of the
cylinder to be easily coated with the protective coating. Further,
because a header is employed, the bottom of the vessel may be used
to accumulate solids that do not pass through the cartridges and,
because the bottom of the vessel is not needed to collect treated
water, a greater portion of the height of the vessel is utilized
for cartridges thereby increasing the treatment capacity of each
vessel.
[0010] In accordance with another embodiment of the present
invention, an apparatus and method are provided for treating or
polishing an organic compound-containing waste water with a
contained volume of organophilic media wherein the organophilic
media degrades with time due to continued adsorbance of the organic
compound(s) from the waste water onto the media.
[0011] In accordance with a preferred embodiment, the preferred
media is an organophilic clay and the contained volume of
organophilic clay includes a probe disposed within the
clay-containing vessel, in contact with the organophilic clay, for
monitoring an electrical property of the organophilic clay,
preferably by monitoring the electrical conductance or electrical
resistance of the organophilic clay and the electrical probe, to
obtain a visual or audible signal when it is time to regenerate or
replace the organophilic clay (before the organophilic clay has
adsorbed so much organic material that its capacity for further
adsorbance of organics is insufficient to provide effluent water of
sufficient purity). It is anticipated that radio frequency or
ultrasonic monitoring of the waste water being treated will serve
as suitable substitutes for electrical conductance or resistance
measurements.
[0012] In accordance with another embodiment of the present
invention, the above-described drawbacks of a sump tank system for
separation of water from oils and other hydrocarbons have been
eliminated by the apparatus and method of the present invention
wherein the sump tank water is conveyed for contact with an
organophilic media for final separation of hydrocarbons such as oil
and paraffins from the water collected on work deck areas of an
offshore drilling platform, preferably while the organophilic media
is monitored so that it can be replaced before it becomes
ineffective.
[0013] In brief, one aspect of the present invention is an improved
vessel design for accommodating organophilic cartridges in a more
space efficient manner. Specifically, the improved vessel design
includes an inlet and an outlet. A header is connected to the
outlet and disposed inside the vessel near the bottom thereof. The
header is connected to one or more permeable conduits that extend
upward therefrom. Organophilic media cartridges can then be stacked
on the permeable conduits. A pressure drop between the inlet and
the outlet causes the contaminated liquid to flow radially inwardly
through the permeable outer covers of the cartridges, through the
media, through the permeable inner tubes of the cartridges and into
the permeable conduits. Because intimate contact between the media
and liquid results in adsorption of the hydrocarbon contaminate on
the media, treated water passes through the inner tubes of the
cartridges and into the permeable conduits. The treated water then
flows down through the conduits, through the header and out of the
vessel through the outlet.
[0014] Another aspect of the present invention is to provide a
removable header connected to the treated fluid outlet and disposed
inside the vessel. By enabling the header to be removable, the
header may be removed and/or replaced when necessary. The
employment of a header avoids the use of the bottom of the vessel
for collecting treated fluid and thereby enables a greater
proportion of the height of the vessel to be used for stacked
filter cartridges thereby increasing the capacity of each vessel
while not increasing the horizontal footprint of the vessel.
[0015] Another aspect of the present invention is directed toward
an improved method for manufacturing vessels for accommodating
organophilic cartridges for treating hydrocarbon-contaminated
water.
[0016] Another aspect of the present invention is directed toward a
method of manufacturing an apparatus for separating hydrocarbons
from a water/hydrocarbon mixture. The manufacturing method includes
the steps of providing a hollow cylinder having an open top end, an
open bottom end and an inside surface, welding a bottom structure
to the bottom end of the cylinder to enclose the bottom end of the
cylinder. The bottom structure includes an inside surface with a
drain outlet with a valve disposed exterior to the bottom structure
for opening and closing the drain outlet. The bottom structure also
includes a treated water outlet which has an inner end disposed
inside the bottom structure. The method further includes the steps
of coating the inside surface of the bottom structure and the
inside surface of the cylinder with a protective coating,
connecting a header to the inner end of the treated water outlet,
connecting at least one permeable conduit to the header, and
placing at least one cartridge on the conduit. The cartridge
includes a permeable outer cover and a permeable inner tube through
which the conduit extends. The cartridge contains an organophilic
media between the outer cover and the inner tube. Intimate contact
between the media and liquid results in adsorption of the
hydrocarbon in the liquid on the media. Finally, the method
includes the steps of attaching a removable top structure on the
top end of the cylinder.
[0017] Yet another aspect of the present invention is directed
toward a method of separating water from a liquid that comprises a
combination of water and a hydrocarbon contaminate. The separation
method includes the step of flowing the liquid into a vessel that
includes an outlet, a header connected to the outlet and at least
one permeable conduit connected to the header. The conduit passes
through a plurality of cylindrical cartridges. Each cartridge
includes a permeable outer cover, a permeable inner tube and
contains an organophilic media between the outer cover and inner
tube. The method further includes the step of providing a negative
pressure gradient between a portion of the vessel exterior to the
cartridges and the inside of the permeable conduit thereby causing
the liquid to flow radially inwardly through the outer cover of
each cartridge, through the media and through the inner tube before
flowing into the conduit.
[0018] Another aspect of the present invention is directed to an
apparatus for monitoring adsorbance capacity of an organophilic
media by monitoring, continuously or periodically, a property of
the liquid being treated by the organophilic media, particularly
the electrical conductance or electrical resistance of the liquid
being treated. The liquid being treated by the organophilic media
for removal of hydrocarbons therefrom can be an industrial waste
water, ship bilge pump water, produced water, or, in a preferred
embodiment, sump tank water collected on offshore drilling
platforms (hereinafter collectively referred to as "waste water").
The organophilic media preferably is electronically monitored to
provide a recognizable audible or visual signal, preferably an
alarm, to indicate when the organophilic media should be
regenerated or replaced.
[0019] Another aspect of the present invention is to provide an
improved probe for monitoring the organophilic clay when
organophilic clay is used as the organophilic media. A probe in
accordance with the preferred embodiment of the present invention
is disposed within one of the cartridges and includes two spaced
apart elements for monitoring a property of the liquid flowing
through the clay. The elements preferably are aligned transversely
to the radially inward flow of the liquid through the clay. A
convenient property to measure is either the conductivity or
resistivity of the fluid by applying a voltage across the two
spaced apart elements. An increase in the resistivity or a decrease
in the conductivity of the organophilic clay will serve as an
indication that the organophilic clay contains hydrocarbon and
therefore the organophilic clay needs to be regenerated or
replaced. The probe should be placed within the canister and
adjacent to the inner tube of the canister as saturation of the
organophilic clay will begin from the outside or adjacent to the
permeable cover of the canister and proceed inward towards the
inner tube.
[0020] Another aspect of the present invention is to provide an
improved organophilic media canister for separating hydrocarbon
contaminate from water that provides an indication as to when the
organophilic media has become saturated with hydrocarbon and
therefore needs to be replaced or regenerated. The filter canister
of the present invention includes an outer cylindrical permeable
cover, an inner cylindrical permeable tube, an annular bottom
connecting bottom edges of the outer cover to the inner tube, an
annular top connecting top edges of the outer cover to the inner
tube and, in a preferred embodiment, includes a probe connected
between the inner tube and the outer cover, preferably connected to
one of the annular top or annular bottom at a middle position. The
probe includes two spaced apart elements. The spaced apart elements
are each connected to a wire lead. Each wire lead is connected to a
control panel. The elements preferably are aligned transversely to
a radial flow from the outer cover to the inner tube or, in other
words, transversely to a radius defined by a common axis of the
outer cover and the inner tube and which extends between the two
spaced apart elements. Finally, the filter cartridge includes
organophilic media disposed in the space defined by the inner tube,
the outer cover, the annular top and the annular bottom. The
organophilic media surrounds the probe and comes in intimate
contact with liquid flowing through the canister.
[0021] Another aspect of the present invention is to provide a
method of monitoring the changing adsorbance capacity of a
contained volume of organophilic media that is being used to treat
an organic compound-containing waste water for removal of organic
compounds therefrom such that a visible or audible signal is
provided as an indication of when to regenerate or replace the
organophilic media.
[0022] Another aspect of the present invention is to provide a new
and improved method and apparatus for complete separation of oil
from water admixed on an offshore oil well drilling platform so
that the separated water can be returned to the ocean without ocean
contamination, with an oil adsorbent, such as an organophilic
media, while monitoring the oil adsorbent for oil saturation.
[0023] Another aspect of the present invention is to provide a new
and improved method and apparatus for separation of oil and water
including a first gravity separation step that provides for
separation of water and oil by settling to provide layering of the
water in a layer below an oil layer and then draining the lower
water layer from the upper oil layer, and thereafter directing at
least a portion of the separated water layer through a vessel
containing an oil adsorbent for contact with the oil adsorbent for
removal (adsorption) of remaining hydrocarbons entrained with the
drained water layer, while electronically monitoring the oil
adsorbent for oil saturation, such as by installing an electrical
conductivity sensor within the oil adsorbent, such that a
measurement of electrical conductivity of the oil adsorbent
indicates the extent of adsorption capacity remaining in the oil
adsorbent.
[0024] Another aspect of the present invention is to provide a new
and improved method and apparatus for separation of oil and water
including a first gravity separation step that provides for
separation of water and oil by settling to provide layering of the
water in a layer below an oil layer and then draining the lower
water layer from the upper oil layer, and thereafter directing the
separated water layer through a vessel containing an organophilic
media for pressurized contact with the organophilic media, at a
pressure of about atmospheric, preferably at least 10 psig above
atmospheric, for removal (adsorption) of remaining hydrocarbons
entrained with the drained water layer.
[0025] The data of Table I show that, at atmospheric pressure and
up to less than 10 psig water pressure entering the organophilic
media-containing vessel, the effluent is cloudy and contains
detectable levels of oil:
1TABLE I EFFECT OF PRESSURE ON OIL ADSORPTION BY ORGANOPHILIC CLAY
Oil Influent Concentration Concentration via EPA Color of Pressure
and Color Method 413.1 Effluent Atmospheric 100 ppm, dark 27 ppm
Cloudy, dark 1 psig 100 ppm, dark 26 ppm Cloudy, dark 2 psig 100
ppm, dark 24 ppm Cloudy, dark 3 psig 100 ppm, dark 22 ppm Cloudy,
dark 4 psig 100 ppm, dark 21 ppm Cloudy, light 5 psig 100 ppm, dark
20 ppm Cloudy, light 10 psig 100 ppm, dark 12 ppm Clear 15 psig 100
ppm, dark 8 ppm Clear 20 psig 100 ppm, dark 4 ppm Clear 25 psig 100
ppm, dark 1 ppm Clear 30 psig 100 ppm, dark 1 ppm Clear 35 psig 100
ppm, dark Non detect Clear 40 psig 100 ppm, dark Non detect Clear
45 psig 100 ppm, dark Non detect Clear 50 psig 100 ppm, dark Non
detect Clear
[0026] The above and other aspects and advantages of the present
invention will become more apparent from the following detailed
description of the preferred embodiment read in conjunction with
the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a side view of an offshore oil well drilling
platform generally showing the oil and water separating apparatus
and method of the present invention attached to a platform support
structure with an alternative placement of a sump tank;
[0028] FIG. 2 is a side view of one embodiment of an oil and water
separating apparatus and method of the present invention;
[0029] FIG. 3 is a sectional view of an embodiment of a vessel
containing a plurality of organophilic media-containing cartridges
for efficient contact of hydrocarbon-containing water with an
organophilic media contained therein;
[0030] FIG. 4 is an elevational view of a preferred embodiment of a
vessel containing a plurality of organophilic media-containing
cartridges for efficient contact of hydrocarbon-containing water
with organophilic media contained within the cartridges;
[0031] FIG. 5 is a top plan view of the header of the vessel shown
in FIG. 4 and openings within the header for receiving permeable
conduits each of which can extend through a stack of filter
cartridges as shown in FIGS. 3 and 4;
[0032] FIG. 6 is a partially broken-away side view of an embodiment
of a sump water polishing unit of the present invention, containing
multiple, stacked cartridges (FIGS. 3 and 4), wherein one of the
cartridges is equipped with a probe for indicating when the
cartridge becomes saturated, or nearly saturated, with
hydrocarbons, so that the sump water can be directed into another
polishing unit while cartridges are replaced;
[0033] FIG. 7 is a sectional elevational view of a preferred
embodiment of a probe for placement within an organophilic
media-containing filter cartridge which provides a signal
indicating when the media of said cartridge is sufficiently
contaminated or saturated with hydrocarbon so as to need
replacement or regeneration;
[0034] FIG. 8 is a top plan view of the top cap of the probe shown
in FIG. 7;
[0035] FIG. 9 is a bottom plan view of the bottom cap of the probe
shown in FIG. 7;
[0036] FIG. 10 is an elevational view of one of the elements of the
probe shown in FIG. 7;
[0037] FIG. 11 is an elevational view of a preferred embodiment of
an organophilic media-containing cartridge shown in FIGS. 3 and
4;
[0038] FIG. 12 is a top plan view of the organophilic
media-containing cartridge shown in FIG. 11;
[0039] FIG. 13 is a sectional view of an annular bottom plate of an
organophilic media-containing filter cartridge made in accordance
with the present invention; and
[0040] FIG. 14 is a partial side plan view of a filter canister
illustrating the position of a probe therein.
[0041] It should be understood that the drawings are not
necessarily to scale and that the embodiments are sometimes
illustrated by graphic symbols, phantom lines, diagrammatic
representations and fragmentary views. In certain instances,
details which are not necessary for an understanding of the present
invention or which render other details difficult to perceive may
have been omitted. It should be understood, of course, that the
invention is not necessarily limited to the particular embodiments
illustrated herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] Turning now to the drawings, and initially to FIG. 1, there
is shown an offshore drilling platform generally designated by
reference numeral 10, including a work deck support structure 12
for supporting a plurality of stacked work decks at a substantial
height above an ocean water level 14. The work decks commonly
include a cellar deck 16 at a lowest work deck level, a second deck
18 located directly above the cellar deck 16, a third deck 20
disposed directly above deck 18, and a main deck 22 at an uppermost
work deck level. In extant offshore drilling platforms, a sump tank
24 has been connected to the drilling platform 10 at the cellar
deck level 16 and rainwater, including entrained hydrocarbons,
particularly oil, paraffins and surfactants have been directed from
all deck levels, which are contained so that rainwater and
entrained hydrocarbons do not spill over to the ocean, to drain by
gravity into the sump tank 24. It has been found that further
separation of hydrocarbons from rainwater is required for effective
elimination of ocean water contamination by providing a secondary
hydrocarbon recovery apparatus and method for organophilic media
treatment of the rainwater separated by gravity in the sump tank 24
or 24A.
[0043] In accordance with a preferred embodiment of the present
invention, it has been found that the apparatus and method of the
present invention function best when the sump tank 24A is disposed
on or near a boat landing deck level 26 (FIG. 1) of the offshore
drilling platform 10. However, the sump tank can also be disposed
at an upper level, in accordance with the present invention, as
indicated by reference numeral 24 in FIG. 1.
[0044] In accordance with a preferred embodiment of the present
invention, it has been found that the apparatus and method of the
present invention function best when the oil-contaminated water
treated in the organophilic media-containing vessel is pressurized
above atmospheric pressure, preferably to at least about 10 psig,
while in contact with the organophilic media. In accordance with an
important feature of the present invention, when the contaminated
water is pressurized to at least 5 psig, preferably to at least 10
psig, the effluent sent back to the ocean is clear (not cloudy) and
has surprisingly less remaining oil as a result of pressurized
contact of the oil-containing water with the organophilic
media.
[0045] Pressurized contact of the oil-containing water with the
organophilic media can be accomplished in a number of ways. One
method of establishing pressurized contact of oil-contaminated
water with the organophilic media, when used on an offshore
drilling platform, is by placement of sump tank 24A at the cellar
deck level 16, and by securing the organophilic media-containing
cartridge 44 at or near the boat landing deck level 26 (such that
at least a portion of the organophilic media-containing cartridge
44 is within about 10 feet of ocean level). Oil and other
hydrocarbons collected on the production decks 16, 18, 20 and 22
that may accumulate during dry weather on the inner surfaces of the
conduit 28 and inner surfaces of sump tank 24 can be separated from
the water that flows from the decks to the organophilic
media-containing cartridge 44 for recovery and separation in
accordance with the apparatus and method of the present
invention.
[0046] Other expedients for establishing pressure within the
organophilic media-containing cartridge 44 include installing a
valve 47 (FIG. 1), or 71 (FIG. 3) or other restrictions in the
effluent conduit 48 (FIG. 1) or 73 (FIG. 3).
[0047] Water and entrained hydrocarbons are conveyed via conduit 28
from the deck areas 16, 18, 20 and 22 along the platform
infrastructure or support leg 12 down to the sump tank 24 or 24A,
preferably sump tank 24A, for convenient servicing and/or
organophilic media cartridge replacement. Although placement of
sump tank 24A at this level has not been expedient with prior art
sump tank gravity water/oil separation, it is now expedient to
dispose the water/oil separation apparatus of the present invention
at or near the boat landing deck level 26 (such that at least a
portion of the sump tank 24A is within about 10 feet of ocean
level) since oil and other hydrocarbons collected on the production
decks 16, 18, 20 and 22 that may accumulate during dry weather on
the inner surfaces of the conduit 28 and inner surfaces of sump
tank 24A can be separated from the water that flows from the decks
to the sump tank 24A for recovery and separation in accordance with
the apparatus and method of the present invention.
[0048] Turning now to FIG. 2, there is shown another embodiment of
the hydrocarbon separation apparatus of the present invention that
includes a gravity separation sump tank 24A for gravity separation
of a lower level of water 28 from a floating layer of oil 30. The
water 29 is conveyed through a water outlet 32 disposed near a
bottom of the sump tank 24A through a water leg 34 in the shape of
an inverted U. The water leg 34 achieves gravity flow of water
through the water leg 34 only when the level of water within the
sump tank 24A reaches height h, above an uppermost or base portion
34A of water leg 34. The sump tank 24A includes an inner, contained
float valve housing 36 open at its top 38 for receiving oil from
oil level 30 when the level of liquid within the sump tank 24
reaches height h'. Float valve 40 is disposed within inner housing
36 and is connected to a pump (not shown) for pumping oil into an
oil recovery vessel when a floating ball portion 41 of float valve
40 rises to a predetermined level within inner valve housing 36 as
a result of oil entering inner vessel 36 when the liquid level h'
is reached within sump tank 24A. While h and h' are shown to be
approximately equal, h may be smaller than h' in order to achieve
water removal without oil pumping, as well known in the art.
[0049] In accordance with an important feature of the present
invention, a downwardly extending leg portion 42 of water leg 34 is
operatively interconnected to, and in fluid communication with, one
or more sump water polishing units 44 containing a volume of oil
adsorbent, particularly an organophilic media. The separated water
flows by gravity through water leg conduit 42 and is conveyed
through conduit 42 into sump water polishing unit 44 containing
organophilic media. The organophilic media within sump water
polishing unit 44 adsorbs the hydrocarbons, oil and other organic
materials entrained with the water flowing through conduits 42 and
44 for essentially complete hydrocarbon removal (less than about 10
parts per million, preferably less than about 1 part per million
organics after organophilic media treatment). The treated water
flows by gravity through water exit opening 46 in the sump water
polishing unit 44 and through exit conduit 48 back to the ocean
water 14.
[0050] It will be noted that FIG. 2 is a simplified drawing of an
actual apparatus which, preferably, would include a plurality of
vessels 44 connected downstream of one or more sock filters (not
shown). The vessels 44 would also be connected upstream of one or
more activated charcoal filters (not shown) or other suitable
filter as a final polishing step before the water is returned to
the ocean. Such sock filters and activated charcoal or carbon
filters are well known to those skilled in the art.
[0051] As shown in FIGS. 3 and 6, the sump water polishing unit 44
includes an outer, fluid-impermeable housing 48 having a water
inlet 42 interconnected through the housing 48 so that contaminated
water enters the polishing unit 44 and then enters the organophilic
media-containing vessels or cartridges 55, through a plurality of
apertures 56. The organophilic media-containing cartridge 55 is
water-permeable by virtue of the water flow apertures 56 that are
sized sufficiently small such that organophilic media granules do
not pass therethrough. Water entering the polishing unit 44 through
water inlet conduit 42 and apertures 56 flows radially inwardly
into longitudinal, axial, central conduits 50, 51, 52, 53 and 54,
each containing treated water-receiving apertures 57 for receiving
the organophilic media-treated water. Organophilic media contained
in cartridges 55 adsorbs any oil and organics contained in the
water and the clean water exits through exit openings 59, 61, 63,
65 and 67 in each stack of cartridges 55 and the clean water
collectively exits the housing 48 through exit conduit 69 and
through valve 71 and then is returned to the ocean via outlet
73.
[0052] Turning to FIG. 4, another embodiment of a vessel 100
containing stacks of cartridges, one of which is shown at 102. Each
cartridge stack includes a plurality of annular cartridges 104
through which a porous conduit 106 extends. The porous conduit 106,
instead of being connected to a porous tube sheet 111 as shown in
FIG. 3, instead is connected to a header 108 which is disposed
within a bottom section 110 of the vessel 100.
[0053] Turning to FIG. 5, the header 108 is connected to a filtered
water outlet 112 which includes a flange 114 which is connected to
the flange 116 of the header 108 by a plurality of fasteners, such
as bolts (not shown). The header is also supported within the
vessel, or more specifically, within the bottom structure 110 (see
FIG. 4) of the vessel by a plurality of supports shown at 118. The
header 108 includes a plurality of openings 120, each of which
receives a permeable conduit 106 (see FIG. 4). In the embodiment
illustrated in FIGS. 4 and 5, the header 108 is connected to 23
permeable conduits and therefore supports 23 stacks of cartridges
104. By providing the header 108 within the bottom structure 110 of
the vessel 100, the permeable tube sheet 111 shown in FIG. 3 is
eliminated and the bottom section 110 of the vessel can be used to
collect accumulated solids, or solids which do not pass through the
outer covers of the filter cartridges 104. A drain 122 is provided
for purposes of flushing out the accumulated solids which settle in
the bottom structure 110 of the vessel 100. In contrast, as shown
in FIG. 3, solids will accumulate on top of the tube sheet 111.
Thus, the solids must be removed from above the tube sheet 108
using one or more nozzle openings shown at 109 in FIG. 3. As shown
in FIG. 4, these additional nozzle openings are not required in the
vessel 100 because the accumulated solids are easily flushed down
the drain pipe 122.
[0054] Further, by utilizing the header 108 and eliminating the
tube sheet 11, the interior space of the vessel 100 is more
efficiently utilized. Specifically, a greater proportion of the
interior volume of the vessel 100 is available for stacking
cartridges 104. In contrast, the design shown in FIG. 3 requires
the cartridges to be stacked on top of the tube sheet 111 and the
filtered water to be collected in the bottom area 103 before
flowing out through the exit conduit 69.
[0055] Still further, the construction of the vessel 100
facilitates both the assembly and the painting or the application
of protective coating to the inside of the vessel 100.
Specifically, the bottom structure 110 is equipped with the drain
122 and the filtered water outlet 112. The bottom structure 110 can
then be welded to the cylindrical portion 124 of the vessel 100. At
this point, the inside surfaces of the cylindrical section 124 and
the bottom structure 110 can be painted with a protective coating
to prevent rust and corrosion caused by salt water and/or acidic
water. The welding seam shown at 126 can be easily coated with the
protective coating.
[0056] In contrast, the vessel 44 of FIG. 3 requires additional
painting steps depending upon when the tube sheet 111 is installed
in the cylindrical section 105 of the vessel 44. Specifically, both
sides of the tube sheet must be coated with the protective
material. After the bottom structure 103 is installed and welded
onto the cylindrical section 105, the weld seam 109 must be coated.
Thus, the additional openings 109 and manway opening 107 are
provided to make the necessary repairs to the inside surface of the
vessel 44 along the weld seam.
[0057] The preferred coating material for the vessels used to
separate hydrocarbon contaminants from water or non-acidic water
are modified epoxy phenolic materials. For example, a material sold
under the trademark CARBOLINE, Product No. 187-0500 is a suitable
material for a first coat for the vessels 44, 100 and a material
also sold under the trademark CARBOLINE, Product No. 187-C703 is
suitable as a second coat. For vessels used in acid flow back
operations, the preferred coating materials are mica filled novalac
vinyl esters. A suitable material for a first coat is sold under
the trademark SENTRY POLYMERS, Product No. 5302-HT and a suitable
material for a second coat is also sold under the trademark SENTRY
POLYMERS, Product No. 5302-HT.
[0058] As shown in FIG. 5, an extremely dense number of stacks of
cartridges 104 is provided by the header 108. Specifically, the
header 108, as shown in FIG. 5, includes 23 openings 120, and
therefore 23 porous conduits 106 and therefore 23 stacks 102 of
cartridges 104. Accordingly, the volumetric flow rate that can be
handled by the vessel 100 is substantially greater than the
volumetric flow rate that can be handled by the vessel 44. Of
course, smaller vessels with fewer stacks of cartridges and large
vessels with more stacks of cartridges are anticipated.
[0059] Organophilic Clay
[0060] The terms "organophilic clay" and "organoclay" are used
herein interchangeably to refer to various types of clay, e.g.,
smectites, that have organoammonium ions substituted for cations
between the clay layers. The term "organoammonium ion substituted"
refers to a substituted ammonium ion in which one or more hydrogen
atoms are replaced by an organic group. The organoclays are
essentially solid compounds that have an inorganic and an organic
phase.
[0061] The preferred clay substrates for use in this invention are
the smectite-type clays, particularly the smectite-type clays that
have a cation exchange capacity of at least 75 milliequivalents per
100 grams of clay. Useful clays for such purpose include the
naturally occurring Wyoming variety of swelling bentonite and
similar clays, and hectorite, which is a selling magnesium-lithium
silicate clay. The clays are preferably converted to the sodium
form if they are not already in this form. This can be effected by
a cation exchange reaction with a soluble sodium compound. These
methods are well-known in the art. Smectite-type clays prepared
synthetically can also be utilized, such as montmorillonite,
bentonite, beidelite, hectorite, saponite, and stevensite.
[0062] The organoclays useful in this invention also include those
set forth in U.S. Pat. No. 2,531,427 to Hauser. These organoclays
are modified clays which exhibit inorganic liquid, some of those
characteristics that untreated clays exhibit in water. For example,
they will swell in many organic liquids and will form stable gels
and colloidal dispersions.
[0063] Generally, the quaternary ammonium salt substituted onto the
clay has organic groups attached to the clay that will range from
aliphatic hydrocarbon of from 1 to 24 carbons to aromatic organic
molecules, such as benzyl groups that could have a host of groups
substituted on the benzyl ring. The number of benzyl versus
straight chain hydrocarbons substituted on the ammonium ion can
vary from 3 to 0 aromatic substituents per aliphatic substituent
(i.e., dimethyl dioctododecyl 0:2, methyl benzyl dioctododecyl 1:2,
dibenzyl dioctobenzyl 1:1, tribenzyl octadecyl 3:1, and methyl
dibenzyl octodecyl 2:1). The amount of quaternary ammonium salt
substituted on the clay can vary between 0.5% to 50% by weight.
[0064] Preferred organoclays useful in the invention comprises one
or more of the following types of quaternary ammonium
cation-modified montmorillonite clays: 1
[0065] wherein R.sub.1 is an alkyl group having at least 10 carbon
atoms and up to, for example, 24 atoms, and preferably having a
chain length of from 12 to 18 carbon atoms; R.sub.2 is hydrogen,
benzyl, or an alkyl group of at least 10 carbon atoms and up to,
for example, 24 carbon atoms, and preferably from 12 to 18 carbon
atoms; and R.sub.3 and R.sub.4 are each hydrogen or lower alkyl
groups, i.e., they contain carbon chains of from 1 to 4 atoms, and
preferably are methyl groups.
[0066] Other organoclays utilizable in the invention include benzyl
organoclays such as dimethyl benzyl (hydrogenated tallow) ammonium
bentonite; methyl benzyl di(hydrogenated tallow) ammonium
bentonite; and more generally quaternary ammonium cation modified
montmorillonite clays represented by the formula: 2
[0067] wherein R.sub.1 is CH.sub.3 or C.sub.6H.sub.5CH.sub.2;
R.sub.2 is C.sub.6H.sub.5CH.sub.2; and R.sub.3 and R.sub.4 are
alkyl groups containing long chain alkyl radicals having 14 to 22
carbon atoms, and most preferably wherein 20% to 35% of said long
chain alkyl radicals contain 16 carbon atoms and 60% to 75% of said
long chain alkyl radicals contain 18 carbon atoms.
[0068] The montmorillonite clays that may be so modified are the
principal constituents of bentonite rock, and have the chemical
compositions and characteristics described, for example, in Berry
& Mason, "Mineralogy," 1959, pp. 508-509. Modified
montmorillonite clays of this type (i.e., organoclays) are
commercially available from Southern Clay Products, Inc., Gonzales,
Tex. under such trade designations as CLAYTONE 34 and 40, and are
available from NL Industries, Inc., New York, N.Y. under such trade
designations as BENTONE 27, 34, and 38. Other organoclays useful in
the invention are the higher dialkyl dimethyl ammonium organoclays
such as dimethyl di(hydrogenated tallow) ammonium bentonite; the
benzyl ammonium organoclays, such as dimethyl benzyl (hydrogenated
tallow) ammonium bentonite; and ethylhydroxy ammonium organoclays
such as methyl bis(2-hydroxyethyl)octodecyl ammonium bentonite.
[0069] Oil-adsorption Monitoring Probes
[0070] The organophilic clay adsorbs oil, grease and other
hydrocarbon contaminants and, after a period of time, which depends
upon the flow rate and hydrocarbon contamination level of the
liquid contacting the organophilic clay, the clay becomes "spent",
or saturated with hydrocarbons to an extent that the clay cannot
further adsorb hydrocarbons to an extent that the effluent can be
legally disposed of back into the ocean. Presently, the regulations
do not permit water to be returned to the ocean if it contains more
than 29 ppm hydrocarbons. When the organophilic clay becomes spent,
the water/oil mixture is directed from the cannister containing the
spent clay and flow is contained through a cannister containing
fresh or regenerated organophilic clay.
[0071] In accordance with a preferred embodiment of the present
invention, it has been found that the organophilic clay within one
or more canisters 54 can be electronically monitored, continuously,
or periodically, to detect when the organophilic clay is spent, or
almost spent, e.g., within a short safety factor of becoming spent,
so that the water flow can be directed into another cannister while
regenerating or replacing the spent organophilic clay.
[0072] A waterproof probe 60 (FIG. 6), having two diametrically
opposed non-corrosive hollow circle conductor plates 62 and 64
extending from a probe body 66, is embedded in the organophilic
clay within one or more of the filter cartridges 55. The hollow
circle probe conductor plates 62 and 64 are at a "fixed" distance
from each other "d", e.g., from {fraction (1/2)}" to 1" apart. The
probe conductor body 66 preferably will be about 1" to 4" in length
and extend from a probe support structure 68. The probe support
structure 68 will be affixed to a central, treated-water outlet
conduit 50, 51, 52, 53 or 54 of the cartridges 55 (see FIG. 3).
Electrical wires 70 encased in a watertight jacket 72 will extend
from the probe body 66 and penetrate through a cable gland 73A
mounted in a cover 76 of cartridge 55 through a packing gland
connector 74. A cable jacket 72 provides a waterproof seal around
the electrical wires 70 and extends up from cartridge 55 through
the packing gland connector 74 and wires 70 will provide for
conveyance of an electrical signal from the probe 60 through the
cartridge 55 that houses the organophilic clay and, in a preferred
embodiment, will convey the electrical signal to a nearby probe
junction box 80 which then connects to a control/alarm panel
81.
[0073] It is estimated that a maximum of three probes per sump
water polishing unit (one per stack of cartridges 55) would provide
adequate sampling to determine the adsorbed condition of
organophilic clay in all of the canisters. After proper electrical
connections have been accomplished, DC power is applied to the
control/alarm panel 81 at a desired voltage. A precision calibrated
signal is applied to the probes 60. When sea water or other
non-hydrocarbon-contaminated reference water floods the cartridges
55, a measurement reference is established. The precision
voltage/frequency signal applied to the probes 60 may vary from a
very low frequency bipolar wave up to a frequency in the
"ultrasonic" range.
[0074] As the organophilic clay begins to adsorb oil from the oily
water flowing through the cannister, the sea water is displaced and
squeezed away from the electrical path of the hollow circle probe
plates 62 and 64. The conductance/resistance reference established
from non-hydrocarbon-contaminated water, e.g., sea water, flow is
compared to the data measured as the oil is accumulatively adsorbed
by the organophilic clay. Over time, the dielectric
conductance/resistance path changes--the conductance decreases and
the resistance increases. The electrical path between the hollow
circle probe plates 62 and 64 slowly changes to a higher
"dielectric" value, whereas the probe plates, dielectric and fixed
distance between the plates 62 and 64 now become a "capacitor". The
resulting wave shape and/or signal level produced by the
capacitance and/or conductance of the media (hydrocarbon-containing
seawater) is evaluated by the control/alarm panel 81. If the wave
shape and/or signal level meet a predetermined criteria, the
control circuitry of the panel 81 will issue an alarm signal
(digital or analog) that can be audible and/or visual and can
signal any telemetry or supervisory control and data acquisition
(SCADA) system.
[0075] A preferred embodiment of a probe 150 is illustrated in
FIGS. 7-10. Specifically, the probe body 150 includes two spaced
apart elements 152, 154. Each hollow circle probe tip element 152,
154 is connected to its own wire lead 156, 158. The wire leads,
which are insulated from one another, extend through a protective
jacket 160 and are connected to a probe junctionbox 80 and then
connected to a control panel as shown in FIG. 6. The elements 152,
154 extend into the probe body 162 and are supported by a top cap
164. A bottom cap is shown at 166 which includes a key 168 for
ensuring that the probe is properly aligned within the canister
104. Specifically, the probe is aligned so that the hollow circle
probe tips 152, 154 are aligned parallel to the radial flow of
fluid through the canister. Orthoganal alignment of the hollow
circle probe tips 152, 154 to the radial flow compromises the
performance of the probe. The hollow circle probe tip design allows
full circulation of sea water through and around the surface area
of the probe tips enabling a reliable measurement sample of the
media. As shown in FIG. 10, each probe preferably includes a hollow
circle portion 170 connected to a downwardly protruding shaft 172.
The preferred material for the elements 152, 154 is 316 stainless
steel. Another suitable material is Hasteloy/Incanel. The probe
body tube 162, top cap 164 and bottom cap 166 are made from Hylar
thermoplastic fluoropolymer. The probe tube 162 is about two-thirds
filled with a potting compound. One suitable potting compound is
sold by the Minnesota Mining and Manufacturing Company under the
trademark DP270 (Black Potting Compound).
[0076] FIGS. 11, 12 and 14 illustrate a typical filter cartridge
104. Each cartridge includes a permeable outer cover 130, a
permeable inner tube 132, an annular top 134 and an annular bottom
136. The space defined by the cover 130, tube 132, top 134 and
bottom 136 is filled with organophilic clay. Handles 138, 140 are
provided to facilitate the removal of the cartridges 104 from the
conduits 106 for regeneration of the clay or replacement of the
cartridges 104.
[0077] FIG. 13 is a sectional view of an annular bottom plate of a
cartridge 104. The outer cover 130 is accommodated between the lips
138, 140. The inner tube 132 is accommodated between the lips 142,
144. The probe 150 for evaluating the condition of the clay, or the
fluid flowing through the cartridge 104 is received in the opening
146.
[0078] From the above description, it is apparent that the objects
and advantages of the present invention have been achieved. While
only certain embodiments have been set forth, alternative
embodiments and various modifications will be apparent from the
above description to those skilled in the art. These and other
alternatives are considered equivalents and within the spirit and
scope of the present invention.
* * * * *