U.S. patent application number 14/396892 was filed with the patent office on 2015-04-30 for processing unit and method for separating hydrocarbons from feedstock material.
The applicant listed for this patent is Fulcrum Environmental Solutions Inc.. Invention is credited to Phillip Cauley.
Application Number | 20150118101 14/396892 |
Document ID | / |
Family ID | 47664721 |
Filed Date | 2015-04-30 |
United States Patent
Application |
20150118101 |
Kind Code |
A1 |
Cauley; Phillip |
April 30, 2015 |
PROCESSING UNIT AND METHOD FOR SEPARATING HYDROCARBONS FROM
FEEDSTOCK MATERIAL
Abstract
The present invention relates to systems and methods for
reducing fouling of a surface of an optically transparent element
(102) with a light source. According to one aspect, the invention
is a system including an LED (108) for emitting UV-C radiation, a
mount for directing emitted UV-C radiation toward the optically
transparent element (102), and control circuitry for driving the
LED (108). The system may be used to remove a desired amount of
biofilm.
Inventors: |
Cauley; Phillip; (Flint,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Fulcrum Environmental Solutions Inc. |
Edmonton |
|
CA |
|
|
Family ID: |
47664721 |
Appl. No.: |
14/396892 |
Filed: |
April 25, 2013 |
PCT Filed: |
April 25, 2013 |
PCT NO: |
PCT/CA13/50318 |
371 Date: |
October 24, 2014 |
Current U.S.
Class: |
422/6 ;
250/492.1 |
Current CPC
Class: |
A61L 2/10 20130101; F21V
21/00 20130101; C10G 31/06 20130101; C10G 1/045 20130101 |
Class at
Publication: |
422/6 ;
250/492.1 |
International
Class: |
A61L 2/10 20060101
A61L002/10; F21V 21/00 20060101 F21V021/00 |
Goverment Interests
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Federal funds awarded by the National Science Foundation
under Grant Nos. OCE-0942835 and OCE-0737958 contributed to making
this invention. The U.S. Government has certain rights herein.
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2012 |
CA |
2775338 |
Claims
1. A system for reducing fouling of a surface of an optically
transparent element subjected to a marine environment, the system
comprising: an LED for emitting UV-C radiation; a mount for
directing emitted UV-C radiation toward the optically transparent
element; and control circuitry for driving the LED.
2. The system of claim 1, wherein the optically transparent element
is selected from the group consisting of a window and a lens.
3. The system of claim 1, wherein the emitted UV-C radiation has a
wavelength in a range of about 265 nm to about 295 nm.
4. The system of claim 1, wherein the mount is disposed on a side
of the optically transparent element proximate the surface.
5. The system of claim 4, wherein the LED is disposed in a
watertight enclosure.
6. The system of claim 5, wherein the watertight enclosure
comprises a UV transparent port.
7. The system of claim 1, wherein the mount is disposed on a side
of the optically transparent element remote of the surface.
8. The system of claim 7, wherein the optically transparent element
comprises a UV transparent material.
9. The system of claim 1, wherein the control circuitry is adapted
to maintain a constant duty cycle of the LED.
10. The system of claim 9, wherein the duty cycle is at least about
10%.
11. The system of claim 1, wherein an attenuated dosage reaching
the surface is at least about 0.5 kJ/m.sup.2.
12. The system of claim 1, wherein a kill efficiency at the surface
is at least about 95%.
13. A method for reducing fouling of a surface of an optically
transparent element subjected to a marine environment, the method
comprising the steps of: providing an LED source for emitting UV-C
radiation; driving the LED source to emit UV-C radiation; and
directing emitted UV-C radiation toward the optically transparent
element.
14. The method of claim 13, wherein the optically transparent
element is selected from the group consisting of a window and a
lens.
15. The method of claim 13, wherein the emitted UV-C radiation has
a wavelength in a range of about 265 nm to about 295 nm.
16. The method of claim 13, wherein the emitted UV-C radiation is
directed on a side of the optically transparent element proximate
the surface.
17. The method of claim 16, wherein the LED is disposed in a
watertight enclosure.
18. The method of claim 17, wherein the watertight enclosure
comprises a UV transparent port.
19. The method of claim 13, wherein the emitted UV-C radiation is
directed on a side of the optically transparent element remote of
the surface.
20. The method of claim 19, wherein the optically transparent
element comprises a UV transparent material.
21. The method of claim 13, wherein the LED is driven to maintain a
constant duty cycle.
22. The method of claim 21, wherein the duty cycle is at least
about 10%.
23. The method of claim 13, wherein an attenuated dosage reaching
the surface is at least about 0.5 kJ/m.sup.2.
24. The method of claim 13, wherein a kill efficiency at the
surface is at least about 95%.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S.
Provisional Patent Application Ser. No. 61/671,426 filed on Jul.
13, 2012, the disclosure of which is hereby incorporated herein by
reference in its entirety.
FIELD OF THE INVENTION
[0003] The present invention relates generally to antifouling
systems and, more specifically, to antifouling systems operating in
situ with an LED light source.
BACKGROUND OF THE INVENTION
[0004] The growth and feeding of biofouling organisms (e.g.,
forming a hard substrate community) inhibits the operational
characteristics of industrial objects, such as lenses. Several
approaches are used to address this problem, including using
coatings. However, in many circumstances a coating will not work.
For example, windows of a submerged precision optical instrument
cannot be coated due to concerns with obstructing the clarity of
the windows, thereby affecting the instrument's measurements.
Another approach is to remove the organisms manually, e.g., by
scrubbing wiping akin to a windshield wiper, but the use of
mechanical components can increase the opportunities for failure
and introduce additional complexity and cost into the system.
[0005] Maintaining an uncompromised visual connection through the
window is particularly important in many communications systems.
For example, scientists are deploying unmanned underwater vehicles
(UUV) that, due to their mobility, can expand the reach of seafloor
observatories. These UUVs typically carry sensors on-board and
operate autonomously, carrying out pre-programmed missions. While
certain types of UUVs are tethered by cable to the seafloor
observatories, the tethered UUVs have a short range of motion and
are limited by the length of the tether. Scientists are also
deploying un-tethered UUVs which may be controlled wirelessly by an
acoustic communication system or an optical communication system.
Acoustic communication systems, however, tend to be limited by low
bandwidth and high latency, and do not permit video or other
high-rate data transfers.
[0006] Accordingly, there is a need to provide an antifouling
device that prevents and/or removes organisms from a surface in a
marine environment. There is also a need for such a device to
remove the organisms from a window while maintaining the integrity
of the window for accurate sensor readings and communications.
SUMMARY OF THE INVENTION
[0007] The present invention relates to systems and methods for
reducing fouling of a surface of an optically transparent element
with a light source. By using LEDs, such a system may be more
efficient, have a longer lifetime, and be more compact than
traditional systems. The systems and methods may be further
augmented by varying wavelengths and duty cycle.
[0008] According to one aspect, the invention relates to a system
for reducing fouling of a surface of an optically transparent
element subjected to a marine environment. The system includes an
LED for emitting UV-C radiation, a mount for directing emitted UV-C
radiation toward the optically transparent element, and control
circuitry for driving the LED.
[0009] In accordance with one embodiment of the above aspect, the
optically transparent element is a window or a lens. The emitted
UV-C radiation may have a wavelength between about 265 nm and about
295 nm. The mount may be disposed on a side of the optically
transparent element proximate the surface. The LED may be disposed
in a watertight enclosure, which may have a UV transparent port. In
other embodiments, the mount may be disposed on a side of the
optically transparent element remote from the surface, and the
optically transparent element may be made of a UV transparent
material. In additional embodiments, the control circuitry is
adapted to maintain a constant duty cycle of the LED, which may be
at least about 10%. An attenuated dosage reaching the surface may
be at least about 0.5 kJ/m.sup.2. A kill efficiency at the surface
may be at least about 95%.
[0010] In another aspect, the invention relates to a method for
reducing fouling of a surface of an optically transparent element
subjected to a marine environment. The method includes providing an
LED source for emitting UV-C radiation, driving the LED source to
emit UV-C radiation, and directing emitted UV-C radiation toward
the optically transparent element.
[0011] In accordance with one embodiment of the foregoing aspect,
the optically transparent element is a window or a lens. The
emitted UV-C radiation may have a wavelength between about 265 nm
and about 295 nm. In some embodiments, the emitted UV-C radiation
is directed on a side of the optically transparent element
proximate the surface. The LED may be disposed in a watertight
enclosure, which may have a UV transparent port. In other
embodiments, the emitted UV-C radiation is directed on a side of
the optically transparent element remote from the surface. The
optically transparent element may be made of a UV transparent
material. The LED may be driven to maintain a constant duty cycle,
which may be at least about 10%. In additional embodiments, an
attenuated dosage reaching the surface is at least about 0.5
kJ/m.sup.2. A kill efficiency at the surface may be at least about
95%.
BRIEF DESCRIPTION OF THE FIGURES
[0012] Other features and advantages of the present invention, as
well as the invention itself, can be more fully understood from the
following description of the various embodiments, when read
together with the accompanying drawings, in which:
[0013] FIG. 1A is a schematic, perspective, semi-transparent view
of an optical modem, in accordance with one embodiment of the
invention;
[0014] FIG. 1B is a schematic plan view of the optical modem of
FIG. 1A;
[0015] FIG. 1C is a schematic cross-sectional view of the optical
modem of FIG. 1A taken along line C-C in FIG. 1B;
[0016] FIG. 2 is a schematic diagram of a timer circuit for use
with the optical modem of FIG. 1A, in accordance with one
embodiment of the invention;
[0017] FIG. 3 is a schematic side view of an experimental setup for
testing the effectiveness of UV LEDs, in accordance with one
embodiment of the invention; and
[0018] FIGS. 4A-4E are photographs of substrates subjected to
different UV wavelengths over a period of time.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The invention may be better understood by reference to the
following detailed description, taken in conjunction with the
figures. Various embodiments of the invention relate to a system
for eliminating biofilm on a surface. Other configurations and
variants will be apparent to those skilled in the art from the
teachings herein.
[0020] FIG. 1A depicts an optical modem (or transmitter assembly)
100 with a system 101 for reducing fouling of a surface of an
optically transparent element 102 in a marine environment. The
outer surface of the optically transparent element may be in
contact with marine fluid, making this surface particularly
vulnerable to developing biofilm that supports larger organism
bio-fouling. The system 101 may be configured to remove/prevent the
formation of biofilm. The optically transparent element 102 allows
for the transmission of light therethrough, enabling communications
and sensors reliant on optics to operate within the interior of the
optical modem 100, but which can be obstructed through the
formation of biofilm and related organisms. Embodiments of this
invention are suitable for use with various systems and methods of
optically communicating underwater, including those described in
U.S. Pat. No. 7,953,326, which is hereby incorporated herein in its
entirety.
[0021] The optically transparent element 102 may be located on an
end cap 104 of the optical modem 100. The optically transparent
element 102 can take many different forms, including a window or a
lens (e.g., flat or curved). The end cap 104 may include one or
more mounts 106 extending from an upper side thereof These mounts
106 may be disposed near the periphery of the end cap 104, as
depicted in FIG. 1B. The mounts 106 may be adapted to house an
ultraviolet (UV, including UV-C) light-emitting diode (LED) 108 at
a distal end thereof, such as within a watertight enclosure to
protect the LEDs 108 from the surrounding marine fluid. These LEDs
108 may provide light in a variety of wavelengths, including
wavelengths from about 265 nm to about 295 nm, though greater and
lesser wavelengths may be produced, as well. The enclosure may have
a UV transparent port so that UV light from the LEDs 108 may pass
through the enclosure to the optically transparent element 102. The
mounts 106 may be configured to direct emitted UV-C radiation from
the LEDs 108 toward the optically transparent element 102, for
example, by angling the distal end of the mounts 106 with the LEDs
108 inward and downward toward the optically transparent element
102. With the mounts 106 and the LEDs 108 on the exterior of the
optically transparent element 102 (i.e., in the marine fluid), they
are proximate the surface to be irradiated. The LEDs 108 may be
used alone or in conjunction with others, as described below.
[0022] In certain embodiments, LEDs 110 may be mounted on an
interior of the optically transparent element 102, remote from the
surface to be irradiated, requiring any light intended to reach the
surface to first pass through the material of the optically
transparent element 102. To allow UV radiation to reach the
surface, the optically transparent element 102 may be made of a UV
transparent material. The interior LEDs 110 may be used alone or in
conjunction with the exterior LEDs 108.
[0023] The LEDs 108, 110 may be controlled by a timer/driver
circuit 201, as depicted in FIG. 2. The control circuit 201 may
control the duty cycle of the LEDs 108, allowing a user to control
the period of time the LEDs 108, 110 are on (and thus when they are
off). The circuit 201 may maintain a constant duty cycle of the
LEDs 108, 110 for a period of time, e.g., 80 minutes on and 12
hours off. The duty cycle may be set to any period of time,
including at least about 10% of on time compared to total time. The
system 101 may be configured to dose the surface with a
predetermined amount of light energy and density (e.g., about 0.5
kJ/m.sup.2) and/or to achieve a desired kill efficiency (e.g., at
least about 95%).
[0024] A light emitting array 112 may be used to communicate with
another optical device. In some embodiments, the array may be a
receiver instead of, or in addition to, being an emitter, and may
replace the light emitting array 112 referred to throughout the
specification. The various embodiments of the array may be used for
transmitting or receiving optical signals. The electronics
controlling the LEDs 108, 110 and/or the electronics controlling
the light emitting array 112 may be located on a mounting flange
114 extending from a lower side of the end cap 104. The mounting
flange 114 may be protected from the exterior environment by a
housing 116 and an additional end cap 118. Each of the end caps
104, 118 may have a bore 120, 122 respectively formed therethrough
to provide passage into the optical modem 100, such as for
electrical wiring, as depicted in FIG. 1C. If necessary, these
bores 120, 122 may be covered or sealed to preclude introduction of
marine fluid into the housing 116.
[0025] To use the system 101, the user may pre-program a control
circuit 201 to drive the LEDs 108, 110 to emit UV-C radiation. This
may be done on a set schedule, as part of a constant duty cycle, or
on demand. When an appropriate amount and type of UV-C radiation is
directed toward the optically transparent element 102, biofilm
formed thereon is removed.
[0026] FIG. 3 depicts an experimental setup 301 for comparing the
effects of two separate wavelengths of deep UV LEDs on the growth
of biofilms. The purpose of the experiment was to assess the
effectiveness of both 265 nm and 295 nm UV LEDs for the purpose of
eliminating the primary biofilm that supports larger, obtrusive
biofouling on an underwater substrate or window. This experiment
was intended to test LEDs as sources of deep UV, as well as to
determine the threshold dosages required to prevent fouling.
Previous tests disclosed that high doses of .about.260 nm UV
emitted from lamps would keep a substrate sufficiently clear. LEDs
are of particular interest due to their efficiency, long lifetime
(when driven properly), and compact size.
[0027] The experimental setup 301 includes an LED 308 (one 265 nm
LED and one 295 nm LED in separate assemblies), a housing 316 with
a window 304 for the LED 308 to project through, and a substrate
330 mounted to the housing with connectors 332. Also included, but
not depicted, are a timer circuit, a current driver circuit, a
power supply, underwater cable connectors, Subconn MCIL2M
connectors, general radio connectors, and 5''.times.8''
enclosures.
[0028] The common timer circuit was programmed to a predetermined
duty cycle (i.e., 80 minutes on, 12 hours off). The housings 316,
one containing a 265 nm LED and the other a 295 nm LED (both with
individual driver circuits), were sealed by screwing on their
respective Lexan.TM. substrates 330a, 330b (SABIC Innovative
Plastics; Pittsfield, Mass.). The housings 316 were then connected
to their respective cables, and dangled underwater approximately 1
m below the low-tide line for optimal sunlight and constant
submersion. The cables were then connected to the LED timer
circuit, powered by a 12V DC power supply. The date and time were
noted, and the substrates 330a, 330b were left to be fouled. Every
few days, the housings 316 were recovered and the substrates 330a,
330b were removed without disturbing any potential growth. The
underside of each substrate 330a, 330b was then studied for signs
of growth and photographed (see FIGS. 4A-4E). The substrates 330a,
330b were reinstalled and the housings 316 were again submerged.
This process was repeated until the amount of accumulated
biofouling indicated that the current duty cycle was less or more
than adequate, ordinarily a period of four weeks.
[0029] The first test configuration, with a duty cycle of 20 min on
and 12 hr off (2.5%), was insufficient for antifouling purposes.
Growth on both substrates 330a, 330b was reduced within the
irradiated radii, but not completely. After two weeks, barnacles
had appeared on the windows 304 of both housings 316, a clear sign
of inadequate dosage.
[0030] The second test configuration, with a duty cycle doubled to
40 min on and 12 hr off (5%), yielded interesting results. While
the substrate 330a radiated with 265 nm UV showed little
improvement with the doubling of dosages, the more powerful yet
less effective 295 nm LED 308 was much more successful. A slight
biofilm did form on the 295 nm substrate 330b within its irradiated
radius, but it was clearly more effective than the 265 nm,
lower-power LED 308. Neither window 304 supported any kind of
growth.
[0031] A third test configuration, as indicated in Table 1, was
configured with a duty cycle of 80 min on and 12 hr off (10%). This
time, both substrates 330a, 330b were kept completely clear of
fouling, and there was no discernible difference between the
effects of the two wavelengths of LEDs 308.
TABLE-US-00001 TABLE 1 LED Configuration for Dataset #3 Worst-Case
Attenuated .lamda. Kill P.sub.o Duty Dosage Dosage (nm) Efficiency
(.mu.W) Cycle (kJ/m.sup.2)* (kJ/m.sup.2) 265 95% 300 80 min ON 12
hr 1.37 0.49 OFF 295 25% 500 80 min ON 12 hr 2.29 0.82 OFF
*Research suggests that 0.5 kJ/m.sup.2 will eliminate 98% of
microorganisms.
[0032] FIGS. 4A-4E represent the substrates 330a, 330b throughout
the experiment. In each of FIGS. 4A-4E, the substrate 330a exposed
to 265 nm is on the left and the substrate 330b exposed to 295 nm
is on the right. FIG. 4A is a photograph taken on day 1 of the
experiment, FIG. 4B on day 6, FIG. 4C on day 19, FIG. 4D on day 22,
and FIG. 4E on day 33 (the final day).
[0033] Based on the results of this experiment, one 295 nm UV LED
308 appears to perform just as well or better than a 265 nm UV LED
308 on the same duty cycle, and is therefore more cost effective,
as 265 nm LEDs 308 typically cost more than 295 nm LEDs 308 (e.g.,
$229 for 265 nm, $149 for 295 nm). Dosages of 265 nm UV for
antifouling may start at 1.37 kJ/m.sup.2, and for 295 nm UV may
start at 2.29 KJ/m.sup.2. These dosages may provide a starting
point which a user may back off to a threshold dosage, or may be
increased by a user to provide a safety factor in irradiation.
[0034] To properly ensure transmission of shortwave UV, a specialty
UV transparent window 304 may be used. For wavelengths in the
250-300 nm range, quartz and fused-silica may be suitable material
choices. If an internal cleaning system is desired to prevent
fouling on a window 304, the window should be designed for such an
application to ensure UV reaches the surface at risk of biofouling.
Alternatively, the antifouling system may be external and
self-contained. Consideration may also be given to the fact
shortwave UV may be subject to high attenuation losses in typical
ocean waters, which somewhat limits the distances from the LED to
its target substrate for which the LED can be effective.
[0035] For this experiment, the shortest possible path length
(approximately 1.7 cm) of UV through water was chosen to minimize
attenuation losses. While the attenuation coefficients for this
range of UV in the waters at the test location were not known, a
worst-case scenario estimate with a theoretical coefficient of 0.36
showed that the attenuated dosage to the 265 nm substrate would
have been 0.49 kJ/m.sup.2 for the 80 min duty cycle. This may
explain why the lower-duty cycles did not appear to be effective;
the dosage required to kill 98% of microbes is 0.5 kJ/m.sup.2.
However, in a different environment, the lower-duty cycles may be
sufficient.
[0036] The experiment results suggest that both 265 nm and 295 nm
UV LEDs 308 may be effective for antifouling purposes. As 295 nm
LEDs tend to be less expensive and equally effective, they may be a
preferred choice for the tested duty cycle. It is expected that
experimentation with different wavelengths may produce different
results. For example, a threshold dosage determined by reducing the
UV dosage until one wavelength outperforms the other may be tested
at different frequencies to develop a more versatile system that
administers less obtrusive, seconds-long dosages at a higher rate.
A decrease in off time would allow for lower dosages, decreasing
the time for biofilms to accumulate between doses.
[0037] Various embodiments and features of the present invention
have been described in detail with particularity. The utilities
thereof can be appreciated by those skilled in the art. It should
be emphasized that the above-described embodiments of the present
invention merely describe certain examples implementing the
invention, including the best mode, in order to set forth a clear
understanding of the principles of the invention. Numerous changes,
variations, and modifications can be made to the embodiments
described herein and the underlying concepts, without departing
from the spirit and scope of the principles of the invention. All
such variations and modifications are intended to be included
within the scope of the present invention, as set forth herein. The
scope of the present invention is to be defined by the claims,
rather than limited by the forgoing description of various
preferred and alternative embodiments. Accordingly, what is desired
to be secured by Letters Patent is the invention as defined and
differentiated in the claims, and all equivalents.
* * * * *