U.S. patent number RE36,896 [Application Number 09/224,846] was granted by the patent office on 2000-10-03 for fluid treatment system and process.
This patent grant is currently assigned to Trojan Technologies Inc.. Invention is credited to Jan M. Maarschalkerweerd.
United States Patent |
RE36,896 |
Maarschalkerweerd |
October 3, 2000 |
Fluid treatment system and process
Abstract
A fluid treatment system includes one or more radiation sources
arranged in an irradiation zone with a treatment zone through which
fluid to be treated passes and is irradiated. The radiation zone
has a closed cross section to maintain the fluid within a
predetermined maximum distance form he radiation source.
Preferably, the irradiation zone comprises a reduced
cross-sectional area perpendicular to the direction of fluid flow
and thus the fluid flow velocity is increased through the
irradiation zone.
Inventors: |
Maarschalkerweerd; Jan M.
(London, CA) |
Assignee: |
Trojan Technologies Inc.
(CA)
|
Family
ID: |
26701640 |
Appl.
No.: |
09/224,846 |
Filed: |
December 31, 1998 |
PCT
Filed: |
March 04, 1994 |
PCT No.: |
PCT/CA94/00125 |
371
Date: |
October 17, 1994 |
102(e)
Date: |
October 17, 1994 |
PCT
Pub. No.: |
WO94/20208 |
PCT
Pub. Date: |
September 15, 1994 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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026772 |
Mar 5, 1993 |
5418370 |
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Reissue of: |
318858 |
Oct 17, 1994 |
05590390 |
Dec 31, 1996 |
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Current U.S.
Class: |
422/186.3;
422/24; 422/906 |
Current CPC
Class: |
C02F
1/325 (20130101); C02F 2201/3227 (20130101); C02F
2201/324 (20130101); C02F 2201/326 (20130101) |
Current International
Class: |
C02F
1/32 (20060101); B01J 019/12 (); C02F 001/32 () |
Field of
Search: |
;422/186.3,24,906 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
75569/81 |
|
Dec 1981 |
|
AU |
|
21042/92 |
|
Feb 1994 |
|
AU |
|
23892A |
|
Feb 1981 |
|
EP |
|
421296 |
|
Feb 1911 |
|
FR |
|
14626 |
|
Jan 1912 |
|
FR |
|
434069 |
|
Jan 1912 |
|
FR |
|
855521 |
|
Nov 1952 |
|
DE |
|
2213658 |
|
Oct 1973 |
|
DE |
|
3441535 |
|
Jun 1986 |
|
DE |
|
55-159778 |
|
Dec 1980 |
|
JP |
|
56-37043 |
|
Apr 1981 |
|
JP |
|
57-501911 |
|
Oct 1982 |
|
JP |
|
59-150589 |
|
Aug 1984 |
|
JP |
|
62-263690 |
|
Nov 1986 |
|
JP |
|
63-104696 |
|
May 1988 |
|
JP |
|
63-137793 |
|
Jun 1988 |
|
JP |
|
63-173394 |
|
Nov 1988 |
|
JP |
|
1-176490 |
|
Jul 1989 |
|
JP |
|
1-274894 |
|
Nov 1989 |
|
JP |
|
1-284385 |
|
Nov 1989 |
|
JP |
|
2-174989 |
|
Jul 1990 |
|
JP |
|
2-214589 |
|
Aug 1990 |
|
JP |
|
3-22587 |
|
Mar 1991 |
|
JP |
|
3-288543 |
|
Dec 1991 |
|
JP |
|
4-122463 |
|
Apr 1992 |
|
JP |
|
5-504912 |
|
Jul 1993 |
|
JP |
|
6-47593 |
|
Dec 1994 |
|
JP |
|
8-17935 |
|
Feb 1996 |
|
JP |
|
1385661 |
|
Feb 1975 |
|
GB |
|
82/01703 |
|
May 1982 |
|
WO |
|
94/02680 |
|
Feb 1994 |
|
WO |
|
Other References
"Ultraviolet Systems Prove Their Germ-Fighting Merit", D. Hodges,
reprinted from Florida Specifier, Apr. 1994. .
"The UV Effect on Wastewater", R. Fahey, Water/Engineering &
Management, Dec. 1990. .
"UV Disinfection At The Northfield Water Pollution Control Plant A
Case History", G. Lindroos and O. Karl Scheible. .
"Hydraulic And Microbiological Characterization Of Reactors For
Ultraviolet Disinfection Of Secondary Wastewater Effluent", by
Th.J. Nieuwstad, et al., Wat. Res. vol. 25, No. 7, pp. 775-783,
1991. .
"Municipal Wastewater Disinfection", Design Manual,
EPA/625/1-86/021, Oct. 1986. .
"Ultraviolet Treatment Of Secondary Wastewater Effluent: An Interim
Report", George Baer, Public Works, Feb. 1979. .
Calgon Carbon Motion, Sep. 7, 1999. .
Die Katadyn UV-Verfahrer zur Keimreduktior im Abwassen, Office
National de la Propriete Industrielle, 1.sup.st Addition, Au Brevet
d'Invention Sketch of UVPS System Allegedly Installed in Lebanon,
Mo. WWTP, Jul. 1988..
|
Primary Examiner: Jenkins; Daniel J.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Parent Case Text
This application is a 371 of PCT/CA94/00125 filed 4 Mar. 1994 an is
a continuation-in-part of Ser. No. 08/026,572, filed Mar. 5, 1993,
now U.S. Pat. No. 5,418,370.
Claims
What is claimed is:
1. A gravity fed fluid treatment system comprising a fluid inlet, a
fluid outlet, an irradiation zone disposed between the fluid inlet
and fluid outlet, and at least one radiation source assembly
comprising at least one radiation source and a support therefor,
the at least one radiation source being elongate and having a
longitudinal axis substantially parallel to the direction of fluid
flow through the irradiation zone and being fully submersed in
fluid flow through the irradiation zone, the support being disposed
upstream or downstream of the irradiation zone, the irradiation
zone having a closed cross-section to confine fluid to be treated
within a predefined maximum distance from the at least one
radiation source, said closed cross-section being less than a
cross-section of said fluid inlet.
2. A system according to claim 1, wherein said support has a
longitudinal axis which is disposed in the fluid inlet
substantially perpendicular to the fluid flow.
3. A fluid treatment system according to claim 1 wherein the
cross-sectional area of said irradiation zone is less than the
cross-sectional area of said fluid inlet and the cross-sectional
area of said fluid outlet.
4. A fluid treatment system according to claim 3 wherein the
cross-sectional area of said irradiation zone is less than the
cross-sectional area of the fluid inlet and said irradiation zone
is disposed in a treatment zone including a transition region
connecting said fluid inlet to said irradiation zone, said
transition region reducing pressure loss in said fluid between said
inlet and said irradiation zone.
5. A fluid treatment system according to claim 3 wherein the
cross-sectional area of said irradiation zone is less than the
cross-sectional area of the fluid outlet and said irradiation zone
is disposed in a treatment zone including a transition region
connecting said fluid outlet to said irradiation zone, said
transition region reducing pressure loss in said fluid between said
outlet and said irradiation zone.
6. A fluid treatment system according to claim 2 wherein the
cross-sectional area of said irradiation zone is less than the
cross-sectional areas of said fluid inlet and said fluid outlet,
said irradiation zone being disposed in a treatment zone including
first and second transition regions, said first transition region
connecting said fluid inlet to said irradiation zone and said
second transition region connecting said irradiation zone to said
fluid outlet, said first and second transition regions reducing
pressure loss in said fluid between said fluid inlet and said
irradiation zone and between said irradiation zone and said fluid
outlet, respectively.
7. A fluid treatment system according to claim 6 wherein said at
least one radiation source assembly comprises at least one
ultraviolet lamp and a support therefor.
8. A fluid treatment system according to claim 7 wherein said
.Iadd.at least one .Iaddend.radiation source assembly includes a
sleeve about a portion of the exterior of each .[.of.]. said at
least one ultraviolet lamp.
9. A fluid treatment system according to claim .[.6.]. .Iadd.1
.Iaddend.wherein said longitudinal axis is substantially vertical
and said .[.first transition region.]. .Iadd.system .Iaddend.alters
a substantially horizontal fluid flow through said fluid inlet to a
substantially vertical fluid flow through said irradiation
zone.
10. A fluid treatment system according to claim 9 wherein said
.[.second transition region.]. .Iadd.system .Iaddend.alters said
substantially vertical fluid flow through said .[.first.].
irradiation zone to a substantially horizontal fluid flow through
said fluid outlet.
11. A fluid treatment system according to claim 7, wherein said
longitudinal axis .Iadd.of said at least one radiation source
.Iaddend.is substantially horizontal.
12. A fluid treatment system according to claim 1 further including
cleaning means to remove undesired materials from the exterior of
said at least one radiation source assembly.
13. A fluid treatment system according to claim 12, wherein said
cleaning means comprises a cleaning sleeve surrounding said at
least one radiation source assembly, said cleaning sleeve being
movable between a retracted position wherein a first portion of
said at least one radiation source assembly is exposed to said
fluid flow and an extended position wherein said first portion of
said at least one radiation source .Iadd.assembly .Iaddend.is
covered by said cleaning sleeve.
14. A fluid treatment system according to claim 13 wherein said
cleaning sleeve includes a chamber surrounding and in contact with
the exterior of said at least one radiation source assembly, said
chamber being supplied with a cleaning solution suitable to remove
undesired materials from the exterior of said at least one
radiation source assembly.
15. A fluid treatment system according to claim 14 wherein said
cleaning sleeve includes a seal between the exterior surface of
said at least one radiation source assembly and said cleaning
sleeve, said seal removing a portion of said undesired materials
from the exterior of said at least one radiation source assembly
when said cleaning sleeve is moved between said retracted and
extended positions.
16. A fluid treatment system according to claim 14 wherein said
supply of said cleaning solution is pressurized to said cleaning
sleeve and said cleaning sleeve is extended to said extended
position by said pressure.
17. A fluid treatment system according to claim 16 wherein said
cleaning sleeve is retracted to said retracted position by the
removal of said pressurized cleaning solution from said cleaning
sleeve.
18. A fluid treatment system according to claim 6 including a first
radiation source assembly located upstream of and extending into
said irradiation zone and a second radiation source assembly
located downstream of and extending into said irradiation zone.
19. A radiation source module for use in a fluid treatment system
comprising:
a first support member;
at least one radiation source assembly extending from said first
support member; and
a second support member extending from said first support
member,
wherein said at least one radiation source assembly extends from
said first support member substantially parallel to said second
member, said second support member extending from said first
support member and having a free end to affix the radiation source
module in the fluid treatment system.
20. A radiation source module according to claim 19 wherein said
second support member extends from said first support member to a
greater extent than said at least one radiation source
assembly.
21. A radiation source module according to claim 19 wherein said at
least one radiation source assembly comprises an ultraviolet
source.
22. A radiation source module according to claim .[.20.]. .Iadd.21
.Iaddend.wherein said radiation source assembly further comprises a
sleeve about said ultraviolet source to provide an insulating gap
between said ultraviolet source and fluid passing therearound.
23. A radiation source module according to claim 19 wherein said
.Iadd.first .Iaddend.support member includes conduit means through
which an electrical power supply is provided to said radiation
source assembly.
24. A radiation source module according to claim 21 wherein at
least two of said ultraviolet sources are connected to each first
support member.
25. A cleaning apparatus for a radiation source assembly in a fluid
treatment system, comprising:
a cleaning sleeve engaging a portion of the exterior said radiation
source assembly and movable between a retracted position wherein a
first portion of said radiation source is exposed to a flow of
fluid to be treated and an extended position wherein said first
portion of said radiation source assembly is completely or
partially covered by said cleaning sleeve, said cleaning sleeve
including a chamber in contact with said first portion of said
radiation source assembly and being supplied with a cleaning
solution suitable to remove undesired materials from said first
portion.
26. A cleaning apparatus according to claim 25 further comprising
at least one seal between the exterior surface of said radiation
source assembly and said cleaning sleeve, said at least one seal
removing a portion of said undesired materials from the exterior of
said radiation source assembly when said cleaning sleeve is moved
between said retracted and extended positions.
27. A cleaning apparatus according to claim 25 wherein said supply
of said cleaning solution is pressurized to said cleaning
sleeve.
28. A cleaning apparatus according to claim 27 wherein said
cleaning sleeve is retracted to said retracted position by the
removal of said pressurized cleaning solution from said cleaning
sleeve.
29. A cleaning apparatus according to claim 25 wherein said
cleaning sleeve engages a portion the exterior of at least two
radiation source assemblies.
30. A cleaning apparatus according to claim 29 wherein said
cleaning sleeve is connected to at least one means to move said
cleaning sleeve between said retracted and extended positions.
31. A cleaning apparatus according to claim 30 wherein said at
least one means to move is hydraulically operated.
32. A cleaning apparatus according to claim 30 wherein said at
least one means to move is pneumatically operated.
33. A method of treating a fluid with at least one radiation source
assembly comprising at least one radiation source and a support
therefor, the method comprising the steps of:
(i) providing a gravity fed flow of fluid from a fluid inlet to a
fluid outlet, and irradiation zone being disposed between said
inlet and said outlet;
(ii) disposing the at least one radiation source assembly within
said irradiation zone such that the at least one radiation source
has a longitudinal axis which is substantially parallel to the flow
of fluid and the support is upstream or downstream of the
irradiation zone;
(iii) confining the flow of fluid such that it is within a
predefined maximum distance from and fully submerses the at least
one radiation source, said confining .[.source.]. .Iadd.step
.Iaddend.including the step
of confining the flow of fluid in a closed cross-section which is
smaller than a cross-section of the fluid inlet;
(iv) exposing the flow of fluid to radiation from the radiation
source; and
(v) feeding the flow of fluid from step (iv) to a fluid outlet.
34. A method according to claim 33, wherein said disposing step
includes the step of disposing the radiation source assembly
support such that its longitudinal axis is disposed in the fluid
inlet and is substantially perpendicular to the fluid flow.
35. A method according to claim 33 wherein the flow of fluid is at
a first velocity in said fluid inlet, a second velocity in said
irradiation zone and a third velocity in said fluid outlet.
36. A method according to claim 35 wherein said second velocity is
greater than at least one of said first velocity and said third
velocity.
37. A method according to claim 35 wherein said second velocity is
greater than both of said first velocity and said third
velocity.
38. A method according to claim 37 wherein said third velocity is
substantially equal to said first velocity.
39. A method according to claim 37 wherein prior to step (ii), the
fluid flow is .[.admired.]. .Iadd.admitted .Iaddend.to a transition
zone which increases the velocity thereof.
40. A method according to claim 37 wherein prior to step (v), the
fluid flow is admitted to a transition zone which decreases the
velocity thereof.
41. A method of removal of fouling materials from a radiation
source in situ in a fluid treatment system using a cleaning
apparatus comprising a cleaning sleeve engaging a portion of the
exterior said radiation source assembly and movable between a
retracted position wherein a first portion of said radiation source
is exposed to a flow of fluid to be treated and an extended
position wherein said first portion of said radiation source
assembly is completely or partially covered by said cleaning
sleeve, said cleaning sleeve including a chamber in contact with
said first portion of said radiation source assembly, comprising
the steps of:
(i) providing a supply of a cleaning fluid to a cleaning
chamber;
(ii) moving said cleaning chamber to said extended position;
(iii) maintaining said cleaning fluid in contact with said
portion;
(iv) allowing said cleaning fluid to facilitate removal of fouling
materials from the radiation source; and
(v) moving said cleaning chamber to said retracted position.
42. A method according to claim 41 wherein said cleaning chamber
includes a seal member in slidable engagement with said portion and
sweeping said portion to further remove fouling materials when said
cleaning chamber is moved to at least one of said extended position
and said retracted position.
43. A method according to claim 41 wherein said cleaning chamber
simultaneously contacts a like portion of at least two radiation
sources.
44. A method according to claim 41 wherein said cleaning chamber is
substantially continuously pressurized by said cleaning fluid and
contains inward spray means to remove the fouling materials from
the radiation source.
45. A method according to claim 41 wherein said cleaning chamber is
kept stationary and the radiation source is moved relative thereto
to remove the fouling materials from the radiation source.
46. A method according to claim 41 wherein said cleaning chamber
further comprises scouring means to increase rubbing against said
radiation source while in contact with the cleaning chamber.
.Iadd.
47. A gravity fed fluid treatment system suitable for installation
in an open fluid canal, said system comprising a fluid inlet, a
fluid outlet, an irradiation zone disposed between the fluid inlet
and the fluid outlet, and at least one radiation source assembly
comprising at least one radiation source and a support therefor,
the at least one radiation source being elongate and having a
longitudinal axis substantially parallel to the direction of fluid
flow through the irradiation zone and being fully submersed in
fluid flow through the irradiation zone, the support being disposed
upstream or downstream of the irradiation zone, the irradiation
zone having a closed cross-section to confine fluid to be treated
within a predefined maximum distance from the at least one
radiation source, said closed cross-section being less than a
cross-section of the open fluid canal upstream of said irradiation
zone..Iaddend..Iadd.
48. A gravity fed fluid treatment system suitable for installation
in an open fluid canal, said system comprising:
a fluid inlet;
a fluid outlet;
an irradiation zone disposed between the fluid inlet and the fluid
outlet; and
at least one radiation source assembly comprising at least one
radiation source and a support therefor, the at least one radiation
source being elongate and having a longitudinal axis substantially
parallel to the direction of fluid flow through the irradiation
zone and being fully submersed in fluid flow through the
irradiation zone,
the support being disposed upstream or downstream of the
irradiation zone,
the irradiation zone having a closed cross-section to confine fluid
to be treated within a predefined maximum distance from the at
least one radiation source,
wherein said closed cross-section causes the velocity of fluid flow
therein to be higher than a velocity of fluid flow in the open
fluid canal upstream of said irradiation zone..Iaddend..Iadd.49. A
system according to claim 48, wherein said support comprises a
vertically-extending member partially submersed in a fluid flow
area having a fluid flow velocity which is less than the fluid flow
velocity of the closed cross-section..Iaddend..Iadd.50. A system
according to claim 49, wherein the vertically-extending member is
movable to remove the at least one
radiation source from the irradiation zone..Iaddend..Iadd.51. A
system according to claim 49, wherein the at least one radiation
source is supported by a single vertically-extending
member..Iaddend..Iadd.52. A system according to claim 48, wherein
said closed cross-section has inner walls which are configured to
follow contours of the at least one radiation
source..Iaddend..Iadd.53. Apparatus for irradiating fluid in an
open fluid canal of a gravity-fed fluid treatment system,
comprising:
an irradiation zone disposed in the open fluid canal and having a
closed cross-section for confining the fluid flow, such that a
fluid flow velocity in the irradiation zone is higher than a fluid
flow velocity upstream of the irradiation zone in the open fluid
canal;
a plurality of elongate ultraviolet lamps disposed in the
irradiation zone with their longest axes substantially parallel to
the direction of fluid flow therethrough;
a plurality of supports for holding said plurality of ultraviolet
lamps in the closed cross-section irradiation zone, said plurality
of supports being positioned upstream of the irradiation zone in
the open fluid canal, each support being movable with respect to
the irradiation zone so that the ultraviolet lamps may be removed
from the irradiation zone;
a plurality of protective sleeves respectively disposed to cover
the plurality of ultraviolet lamps;
a plurality of sleeve cleaners, each disposed around an outer
surface of a corresponding sleeve; and
driving apparatus which drives the plurality of sleeve cleaners
along the
plurality of sleeves to clean the sleeves..Iaddend..Iadd.54.
Apparatus for irradiating fluid in a gravity-fed fluid treatment
system, comprising:
an enclosed flow zone which physically restricts the flow of fluid
therethrough as compared to a relatively less restricted flow zone
upstream of said enclosed flow zone;
a plurality of elongate radiation sources disposed within the
enclosed flow zone so that a longitudinal axis of each radiation
source is substantially parallel to a direction of the fluid flow
through said enclosed flow zone; and
a support member for holding one or more of said plurality of
radiation sources in the enclosed flow zone, at least a portion of
said support member being disposed outside of said enclosed flow
zone,
said enclosed flow zone having inner walls which are configured to
follow contours of portions of said plurality of radiation
sources..Iaddend..Iadd.5. Apparatus according to claim 54, wherein
said support member comprises a vertically-extending member
disposed in a fluid flow area which has a fluid flow velocity which
is less than a fluid flow velocity of the enclosed flow
zone..Iaddend..Iadd.56. Apparatus according to claim 55, wherein
the vertically-extending member is movable to remove the one or
more of said plurality of radiation sources from the enclosed flow
zone..Iaddend..Iadd.57. Apparatus according to claim 55, wherein
each of said one or more of said plurality of radiation sources is
supported by a single vertically-extending
member..Iaddend..Iadd.58. A system for treating fluid in an open
fluid canal of a gravity fed fluid system, comprising:
a closed cross-section irradiation zone in which the velocity of
fluid flowing therethrough is higher than the velocity of fluid
flowing in a zone upstream of said irradiation zone in the open
fluid canal;
a plurality of ultraviolet lamps disposed in said irradiation zone
parallel to a direction of fluid flow therethrough, said
ultraviolet lamps for treating the fluid flowing through the closed
cross-section irradiation zone; and
at least one support which holds one or more of the plurality of
ultraviolet lamps in the irradiation zone, the at least one support
being disposed upstream of the irradiation zone in the open fluid
canal,
wherein said closed cross-section irradiation zone is defined at
least in
part by a main body restricting fluid flow..Iaddend..Iadd.59. A
system according to claim 58, wherein said at least one support
comprises a vertically-extending member disposed in a fluid flow
area having a fluid flow velocity which is less than a fluid flow
velocity of the closed cross-section irradiation
zone..Iaddend..Iadd.60. A system according to claim 59, wherein the
vertically-extending member is movable to remove the one or more of
the plurality of ultraviolet lamps from the closed cross-section
irradiation zone..Iaddend..Iadd.61. A system according to claim 59,
wherein each of said one or more of the plurality of ultraviolet
lamps is supported by a single vertically-extending member.
.Iadd.62. A system according to claim 58, wherein said closed
cross-section irradiation zone has inner walls which are configured
to follow contours of the plurality of ultraviolet lamps disposed
in the irradiation zone..Iaddend..Iadd.63. A radiation module for
an open-canal gravity-fed fluid treatment system having an
irradiation zone, comprising:
a plurality of radiation sources for disposal in the irradiation
zone and having longitudinal axes which are substantially parallel
to a direction of fluid flow through the irradiation zone;
a vertically-extending support member coupled to said plurality of
radiation sources such that each radiation source is supported by a
single vertically-extending support member, said support member
holding the plurality of radiation sources in the irradiation zone,
said support member being movable with respect to the irradiation
zone so that said plurality of radiation sources may be removed
from the irradiation zone; and
cleaning means, movable in the direction of the longitudinal axes
of the radiation sources, for cleaning outer surfaces of the
radiation sources while said radiation sources are in the
irradiation zone..Iaddend..Iadd.64. A module according to claim 63,
further comprising an additional support member for coupling said
support member to the fluid
treatment system..Iaddend..Iadd.65. A module according to claim 63,
wherein said plurality of radiation sources are
horizontally-disposed, and wherein said vertically-extending
support member comprises a vertical member..Iaddend..Iadd.66. A
fluid treatment system for a gravity fed fluid canal through which
fluid to be treated flows, comprising:
a main body installed across the fluid canal such that the main
body is at least partly immersed in the fluid of said canal so as
to direct the fluid to an irradiation zone;
an irradiation zone through which the fluid flows before returning
to the fluid canal; and
at least one radiation source disposed in said irradiation zone to
treat fluid with radiation, said at least one radiation source
having its longest axis parallel to said fluid flow,
said irradiation zone having a closed cross-section to confine
fluid within a predefined maximum distance from the at least one
radiation source,
said irradiation zone having a cross-sectional area that is less
than that
of the fluid canal..Iaddend..Iadd.67. A system according to claim
66, further comprising a support member for supporting the at least
one radiation source in the irradiation zone..Iaddend..Iadd.68. A
system according to claim 67, wherein said support member comprises
a vertically-extending member partially submersed in a fluid flow
area having a fluid flow velocity which is less than a fluid flow
velocity of the irradiation zone..Iaddend..Iadd.69. A system
according to claim 68, wherein the vertically-extending member is
movable to remove the at least one radiation source from the
irradiation zone..Iaddend..Iadd.70. A system according to claim 68,
wherein said at least one radiation source is supported by a single
vertically-extending member..Iaddend..Iadd.71. A system according
to claim 66, wherein said irradiation zone closed cross-section has
inner walls which are configured to follow contours of the at least
one radiation source disposed in the irradiation
zone..Iaddend..Iadd.72. A system according to claim 66, wherein
said at least one radiation source is mounted on a support therefor
with the support being disposed in an area upstream or downstream
of said irradiation zone..Iaddend..Iadd.73. A fluid treatment
system for irradiating fluid flowing in an open fluid canal,
comprising:
an irradiation zone disposed in said open fluid canal to receive
the fluid flow from the open fluid canal;
said irradiation zone having a closed cross-sectional area that is
smaller than the cross-sectional area of the fluid flowing in the
open fluid canal;
a plurality of elongate ultraviolet lamps disposed in said
irradiation zone with the longest axis of each lamp being
substantially parallel to the direction of fluid flow; and
at least one vertically-extending support member for supporting
said plurality of ultraviolet lamps in the irradiation zone;
each of said plurality of ultraviolet lamps being supported by a
single vertically-extending support member;
said at least one vertically-extending support member being
disposed in an area upstream or downstream of said irradiation
zone..Iaddend..Iadd.74. A system according to claim 73, wherein the
closed cross-section causes a fluid flow velocity in the
irradiation zone to be higher than a fluid flow velocity in the
open fluid canal..Iaddend..Iadd.75. A system according to claim 73,
wherein said support member comprises a vertically-extending member
partly submersed in a fluid flow area having a fluid flow velocity
which is less than a fluid flow velocity in the irradiation zone
closed
cross-section..Iaddend..Iadd.76. A system according to claim 75,
wherein the vertically-extending member is movable to remove the
plurality of ultraviolet lamps from the irradiation
zone..Iaddend..Iadd.77. A system according to claim 73, wherein the
irradiation zone closed cross-section has inner walls configured to
follow contours of the plurality of ultraviolet
lamps..Iaddend..Iadd.78. A system according to claim 73, wherein
said vertically-extending support member is movably mounted with
respect to said fluid treatment system so that said ultraviolet
lamps may be moved into and out of said irradiation
zone..Iaddend..Iadd.79. A system according to claim 73, wherein
each said ultraviolet lamp is located within a sleeve, and wherein
said system further includes a cleaning member disposed about said
sleeve and which is reciprocally movable from a retracted position
to an extended position to clean the surface of said
sleeve..Iaddend..Iadd.80. A radiation source module for an open
fluid treatment system which includes a fluid inlet, and a fluid
outlet, comprising:
a vertically-extending support member for disposal in the
fluid;
a plurality of elongated radiation source assemblies extending from
said support member,
each of said radiation source assemblies being supported by a
single vertically-extending support member; and
another support member disposed outside of the fluid and extending
from said vertically-extending support member to movably position
said radiation source module in an irradiation zone in said fluid
treatment system..Iaddend..Iadd.81. A module according to claim 80,
wherein each elongated radiation source assembly includes an
ultraviolet lamp, and further comprises cleaning means for cleaning
each ultraviolet
lamp..Iaddend..Iadd.82. A module according to claim 80, wherein
said another support member is coupled to the fluid treatment
system..Iaddend..Iadd.83. A module according to claim 80, wherein
said vertically-extending support member comprises a vertical
member..Iaddend..Iadd.84. A module according to claim 80, wherein
said vertically-extending support member is movable with respect to
the irradiation zone so as to extract said plurality of radiation
source assemblies from the irradiation zone..Iaddend..Iadd.85. A
method of treating a fluid in an open canal system, comprising the
steps of:
(i) providing a gravity fed flow of fluid at a first velocity in
the open canal;
(ii) feeding the flow of fluid from the open canal through an
elongate irradiation zone at a second velocity which is greater
than the first velocity, the elongate irradiation zone having a
closed cross-section and having disposed therein an elongate
radiation source having a longitudinal axis substantially parallel
to the flow of fluid, the elongate radiation source being connected
to a support disposed in an area upstream or downstream of the
irradiation zone;
(iii) confining the flow of fluid at the second velocity within a
redefined maximum distance from the at least one radiation
source;
(iv) exposing the flow of fluid at the second velocity to radiation
from the radiation source; and
(v) feeding the flow of fluid from step (iv) to the open canal
downstream
of the irradiation zone..Iaddend..Iadd.86. A fluid treatment method
for a gravity fed fluid flow, comprising the steps of:
disposing a main body across an open fluid canal such that the main
body is at least partly immersed in the fluid of said canal;
directing fluid flow to an irradiation zone through which the fluid
flows before returning to the fluid canal;
disposing at least one radiation source in said irradiation zone,
said at least one radiation source having its longest axis parallel
to said fluid flow;
irradiating the fluid flow with the at least one radiation source
in the irradiation zone;
providing said irradiation zone with a closed cross-section to
confine fluid within a predefined maximum distance from the at
least one radiation source; and
providing said irradiation zone with a cross-sectional area that is
less
than that of the fluid canal..Iaddend..Iadd.87. A radiation source
module for use in a fluid treatment system comprising:
a single vertically-extending support member;
a plurality of radiation source assemblies extending from the
support member, the plurality of radiation source assemblies each
comprising at least one radiation source, the at least one
radiation source being elongate with its longitudinal axis
substantially parallel to a direction of fluid flow, the plurality
of radiation source assemblies being supported by the single
vertically-extending support member; and
fastening means to affix the radiation source module in the fluid
treatment system..Iaddend..Iadd.88. A gravity fed fluid treatment
system for an open canal, comprising:
an array of radiation sources disposed in an elongate irradiation
zone having a closed cross-section which provides a fixed geometry
to restrict fluid flow through the irradiation zone as compared to
a flow in the open canal, the array of radiation sources being
disposed substantially parallel to the fluid flow;
a fluid inlet upstream of the irradiation zone;
a fluid outlet downstream of the irradiation zone; and
at least one vertically-extending support for the array of
radiation sources, the at least one vertically-extending support
being partly submersed in the fluid flow upstream or downstream of
the irradiation
zone..Iaddend..Iadd.89. A gravity fed fluid treatment system
comprising:
an open canal for receiving a fluid flow;
an array of elongate radiation sources disposed substantially
parallel to the fluid flow;
an elongate irradiation zone surrounding the array of radiation
sources and having a closed cross-section to (i) restrict the fluid
flow within a predetermined maximum distance from the array of
radiation sources and (ii) to increase a fluid flow velocity in the
irradiation zone with respect to a fluid flow velocity in the open
canal; and
at least one support for the array of radiation sources disposed in
the open canal upstream or downstream of the irradiation
zone..Iaddend..Iadd. . A system according to claim 1 wherein said
at least one radiation source comprises a high intensity
ultraviolet lamp..Iaddend..Iadd.91. A module according to claim 19,
wherein said at least one radiation source assembly comprises a
high intensity ultraviolet lamp..Iaddend..Iadd.92. A method
according to claim 33, wherein said disposing step includes the
step of disposing a radiation source which
comprises a high intensity ultraviolet lamp..Iaddend..Iadd.93. A
system according to claim 47, wherein said at least one radiation
source comprises a high intensity ultraviolet
lamp..Iaddend..Iadd.94. A system according to claim 48, wherein
said at least one radiation source comprises a high intensity
ultraviolet lamp..Iaddend..Iadd.95. Apparatus according to claim
53, wherein each of said plurality of ultraviolet lamps comprises a
high intensity ultraviolet lamp..Iaddend..Iadd.96. Apparatus
according to claim 54, wherein each of said plurality of elongated
radiation sources comprises a high intensity ultraviolet
lamp..Iaddend..Iadd.97. A system according to claim 58, wherein
each of said plurality of ultraviolet lamps comprises a high
intensity ultraviolet lamp..Iaddend..Iadd.98. A module according to
claim 63, wherein each of said plurality of radiation sources
comprises a high intensity ultraviolet
lamp..Iaddend..Iadd.99. A system according to claim 66, wherein
said at least one radiation source comprises a high intensity
ultraviolet lamp..Iaddend..Iadd.100. A system according to claim
73, wherein each of said plurality of elongated ultraviolet lamps
comprises a high intensity ultraviolet lamp..Iaddend..Iadd.101. A
module according to claim 80, wherein each of said plurality of
elongated radiation source assemblies comprises a high intensity
ultraviolet lamp..Iaddend..Iadd.102. A module according to claim
87, wherein said at least one radiation source comprises a high
intensity ultraviolet lamp..Iaddend..Iadd.103. A system according
to claim 88, wherein each of the radiation sources comprises a high
intensity ultraviolet lamp..Iaddend..Iadd.104. A system according
to claim 89, wherein each elongate radiation source comprises a
high intensity ultraviolet lamp..Iaddend.
Description
TECHNICAL FIELD
The present invention relates to a method of treating fluid by
providing a gravity fed flow of fluid to an irradiation zone
comprising at least one radiation source and having a closed
cross-section which confines the flow of fluid within a predefined
maximum distance from the at least one radiation source.
The present invention also relates to a novel method of cleaning a
radiation source assembly located within a fluid flow wherein the
exterior of the source is swept by a cleaning member containing an
appropriate cleaning fluid.
The present invention also relates to a novel system for treating
fluid by exposing it to radiation. Specifically, the present
invention relates to a novel gravity fed system for treating fluids
comprising a treatment zone which includes a irradiation zone
configured to provide a fixed fluid geometry relative to the
radiation sources.
The present invention also relates to a novel radiation source
module for use in a fluid treatment system. Specifically, the
module includes one or more radiation source assemblies connected
to a support member and the support member is designed to permit
insertion and extraction of the
module from the treatment system while the system is in use. The
module is designed such that the radiation source assembly is
prevented from contacting surfaces within the treatment zone of the
system while being installed or removed.
The present invention also relates to a novel cleaning apparatus
for fluid treatment systems. Specifically, the cleaning apparatus
includes one or more cleaning members which may be swept over the
exterior of radiation source assemblies within the fluid treatment
system, the cleaning members containing a suitable cleaning fluid
which contacts the exterior of the radiation source assembly and
loosens and/or removes materials fouling the exterior of the
radiation source assembly.
BACKGROUND ART
Fluid treatment systems are known. For example, U.S. Pat. Nos.
4,482,809, 4,872,980 and 5,006,244 (assigned to the assignee of the
present invention), the contents of each of which are hereby
incorporated by reference, all describe gravity fed fluid treatment
systems which employ ultraviolet (UV) radiation.
Such systems include an array of UV lamp frames which include
several UV lamps each of which are mounted within sleeves extending
between two support arms of the frames. The frames are immersed
into the fluid to be treated which is then irradiated as required.
The amount of radiation to which the fluid is exposed is determined
by the proximity of the fluid to the lamps, the output wattage of
the lamps and the fluid's flow rate past the lamps. One or more UV
sensors may be employed to monitor the UV output of the lamps and
the fluid level is typically controlled, to some extent, downstream
of the treatment device by means of level gates or the like. Since,
at higher flow .[.rams.]. .Iadd.rates.Iaddend., accurate fluid
level control is difficult to achieve in gravity fed systems,
fluctuations in fluid level are inevitable. Such fluctuations could
lead to non-uniform irradiation in the treated fluid.
However, disadvantages exist with the above-described systems.
Depending upon the quality of the fluid which is being treated, the
sleeves surrounding the UV lamps periodically become fouled with
foreign materials, inhibiting their ability to transmit UV
radiation to the fluid. When fouled, at intervals which may be
determined from historical operating data or by the measurements
from the UV sensors, the sleeves must be manually cleaned to remove
the fouling materials.
If the UV lamp frames are employed in an open, channel-like system,
one or more of the frames may be removed while the system continues
to operate, and the removed frames may be immersed in a bath of
suitable acidic cleaning solution which is air-agitated to remove
fouling materials. Of course, surplus or redundant sources of UV
radiation must be provided (usually by including extra UV lamp
frames) to ensure adequate irradiation of the fluid being treated
while one or more of the frames has been removed for cleaning. Of
course, this required surplus UV capacity adds to the expense of
installing the treatment system.
Further, a cleaning vessel containing cleaning solution into which
UV lamp frames may be placed must also be provided and maintained.
Depending upon the number of frames to be cleaned at one time and
the frequency at which they require cleaning, this can also
significantly add to the expense of installing, maintaining and
operating the treatment system.
If the frames are in a closed system, removal of the frames from
the fluid for cleaning is usually impractical. In this case, the
sleeves must be cleaned by suspending treatment of the fluid,
shutting inlet and outlet valves to the treatment enclosure and
filling the entire treatment enclosure with the acidic cleaning
solution and air-agitating the fluid to remove the fouling
materials. Cleaning such closed systems suffers from the
disadvantages that the treatment system must be stopped while
cleaning proceeds and that a large quantity of cleaning solution
must be employed to fill the treatment enclosure. An additional
problem exists in that handling large quantities of acidic cleaning
fluid is hazardous and disposing of large quantities of used
cleaning fluid is difficult and/or expensive. Of course open flow
systems suffer from these two problems, albeit to a lesser
degree.
Indeed, it is the belief of the present inventor that, once
installed, one of the largest maintenance costs associated with
prior art fluid treatment systems is often the cost of cleaning of
the sleeves about the radiation sources.
Another disadvantage with the above-described prior art systems is
the output of the UV lamps. Unfortunately, the UV lamps in the
prior art systems were required to be about five feet in length to
provide the necessary wattage of UV radiation. Accordingly, the UV
lamps were relatively fragile and required support at each end of
the lamp. This increased the capital cost of the system.
Further, due to the somewhat limited output wattage of the UV lamps
in the prior art systems, a great number of lamps were often
required. For example, certain prior art installations employ over
9,000 lamps. Such a high number of lamps adds to the
above-mentioned costs in cleaning lamps as well as the cost of
maintaining (replacing) the lamps.
DISCLOSURE OF THE INVENTION
It is an object of the present invention to provide a novel method
of treating a fluid by irradiation which obviates or mitigates at
least one of the above-mentioned disadvantages of the prior
art.
It is a further object of the present invention to provide a novel
fluid treatment system which obviates or mitigates at least one of
the above-mentioned disadvantages of the prior art.
According to one aspect of the present invention, there is provided
a method of treating a fluid comprising the steps of:
(i) providing a gravity fed flow of fluid to a fluid inlet;
(ii) feeding the flow of fluid from the fluid inlet to an
irradiation zone comprising at least one radiation source and
having a closed cross-section;
(iii) confining the flow of fluid within a predefined maximum
distance from the at least one radiation source;
(iv) exposing the flow of fluid to radiation from the radiation
source; and
(v) feeding the flow of fluid from step (iv) to a fluid outlet.
According to another aspect of the present invention, there is
provided a method of removal of fouling materials from a radiation
source in situ in a fluid treatment system, comprising the steps
of:
(i) providing a supply of a cleaning fluid to a cleaning
chamber;
(ii) moving the cleaning chamber into contact with at least a
portion of the radiation source for a predetermined time period,
the cleaning chamber maintaining the cleaning fluid in contact with
the portion; and
(iii) removing the cleaning chamber from contact with the portion
of the radiation source after the predetermined time period.
According to another aspect of the present invention, there is
provided a gravity fed fluid treatment system comprising a fluid
inlet, a fluid outlet, and an irradiation zone disposed between the
fluid inlet and fluid outlet, the irradiation zone (i) including at
least one radiation source and, (ii) having a closed cross-section
to confine fluid to be treated within a predefined maximum distance
from the at least one radiation source assembly.
Preferably, the irradiation zone is disposed within a fluid
treatment zone including an inlet transition region and an outlet
transition region. The inlet transition region receives the fluid
flow from the fluid inlet and increases its velocity prior to entry
thereof into the irradiation zone. The outlet transition region
receives the fluid flow from the irradiation zone and decreases the
velocity of the fluid flow prior to its entry into the fluid
outlet. Thus, the fluid flow velocity is only elevated within the
irradiation zone to reduce hydraulic head loss of the fluid flow
through the system. It will be appreciated by those of skill in the
art that one or both of the inlet transition region and the outlet
transition region may comprise a tapered section (described in more
detail hereinbelow). Alternatively, a "bell-mouth" shaped inlet and
outlet may be utilized. In either case, the underlying result is a
reduction in hydraulic head loss.
According to another aspect of the present invention, there is
provided a radiation source module for use in a fluid treatment
system comprising: a support member, at least one radiation source
assembly extending from said support member; and fastening means to
affix the radiation source module in the fluid treatment
system.
According to yet another aspect of the present invention, there is
provided a cleaning apparatus for a radiation source assembly in a
fluid treatment system, comprising: a cleaning sleeve engaging a
portion of the exterior said radiation source assembly and movable
between a retracted position wherein a first portion of said
radiation source is exposed to a flow of fluid to be treated and an
extended position wherein said first portion of said radiation
source assembly is completely or partially covered by said cleaning
sleeve, said cleaning sleeve including a chamber in contact with
said first portion of said radiation source assembly and being
supplied with a cleaning solution suitable to remove undesired
materials from said first portion.
According to another aspect of the invention, there is provided a
radiation sensor assembly comprising: a sensor housing; a radiation
transmissive means within said housing and including a portion to
be exposed to a radiation source; a radiation sensor receiving
radiation from said transmissive means; and means to remove
materials fouling said portion.
As used herein, the term "gravity fed" encompasses systems wherein
the hydraulic head of the fluid is obtained from changes in the
altitude of the fluid. It will be understood that such systems
comprise both systems which are naturally gravity fed and systems
wherein the altitude of the fluid is altered via pumps or other
mechanical means to provide a gravity feed.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will be described with
reference to the accompanying drawings, in which:
FIG. 1 illustrates a side section of a prior an fluid treatment
device;
FIG. 2 illustrates an end section of the prior an fluid treatment
device of FIG. 1;
FIG. 3 illustrates a side section of a first embodiment of a
horizontal fluid treatment system in accordance with the present
invention;
FIG. 4 illustrates a radiation source module for use with the
system of FIG. 3;
FIG. 5 illustrates an expanded view of the area indicated at A in
FIG. 4;
FIG. 6 illustrates a portion of another embodiment of a radiation
source module for use with the system of FIG. 3;
FIG. 7 illustrates an expanded view of the area indicated at B in
FIG. 6;
FIG. 8 illustrates a side section of a second embodiment of a
vertical fluid treatment system in accordance with the present
invention; and
FIG. 9 illustrates a radiation sensor assembly.
BEST MODE FOR CARRYING OUT THE INVENTION
For clarity, a brief description of a prior art fluid treatment
device will be presented before discussing the present invention.
FIGS. 1 and 2 show a prior art treatment device as described in
U.S. Pat. No. 4,482,809. The device includes a plurality of
radiation source modules 20, each including a pair of frame legs 24
with UV lamp assemblies 28 extending therebetween. As best shown in
FIG. 2, a plurality of lamp modules 20 are arranged across a
treatment canal 32 with a maximum spacing between lamp modules 20
which is designed to ensure that the fluid to be treated is
irradiated with at least a predetermined minimum dosage of UV
radiation.
While this system has been successful, as discussed above it
suffers from disadvantages in that the arrangement of the lamp
modules 20 makes maintenance of the device relatively labour
intensive. Specifically, replacing lamps or cleaning the sleeves
surrounding the lamps is time consuming and expensive. Also, for
treatment to continue when a lamp module is removed, it is
necessary to provide redundant lamp modules to ensure that the
fluid still receives the predefined minimum dosage of radiation
increasing the cost of the system. Further, depending on the
quality of the fluid and its flow rate, significant numbers of
lamps and sleeves may be required per unit of fluid treated.
Another disadvantage of this prior art system is the difficulty in
controlling fluid level relative to lamp modules 20 at higher flow
rates.
Accordingly, while the above-described prior an systems have been
successful, the present inventor has been concerned with improving
fluid treatment systems to overcome some of these disadvantages.
The present invention will now be described with reference to the
remaining Figures.
Referring now to FIG. 3, a fluid treatment system in accordance
with the present invention is indicated generally at 100. The
system 100 includes a main body 104 which is installed across an
open fluid canal 108 such that the all of the fluid flow through
canal 108 is directed through a treatment zone 112. Main body 104
may be precast concrete, stainless steel or any other material
suitable for use with the fluid to be treated and which is
resistant to the type of radiation employed.
The lower surface of main body 104 includes a central section 116
which extends downward with leading and trailing inclined sections
120 and 124, respectively. A corresponding upraised central section
132 is located on a base 128 of canal 108 beneath central section
116 and includes leading and trailing inclined sections 136 and
140, respectively. Central section 132 may be part of main body 104
or may be part of base 128 (as illustrated).
As can be clearly seen in FIG. 3, sections 116 and 132 form a
narrowed irradiation zone 144, while sections 120 and 136 form a
tapered inlet transition region and sections 124 and 140 form a
tapered outlet transition region.
As will be apparent, irradiation zone 144 presents a closed
cross-section to the fluid to be treated. This provides a fixed
geometry of the fluid relative to irradiation sources (described
hereinafter) to ensure that the fluid is exposed to the predefined
minimum radiation from the irradiation sources. Those of skill in
the art will appreciate that the inner walls of irradiation zone
144 could be designed and configured to substantially follow the
contours of the portions of radiation source modules 148 disposed
therein in order to maximize treatment efficiency at the farthest
points from the radiation source.
At least one of the upstream and downstream faces of main body 104
includes one or more radiation source modules 148 mounted thereto.
Depending on the fluid to be treated, the number of modules 148
provided may be varied from a single upstream module 148 to two or
more modules 148 across both the upstream and downstream faces of
main body 104.
Preferably, main body 104 further includes a radiation sensor 152
which extends into irradiation zone 144 and a fluid level sensor
156 which monitors the level of fluid in the inlet side of
treatment zone 112. As is known to those of skill in the art, if
the level of fluid in the system falls below fluid level sensor
156, an alarm or shutdown of the radiation sources will occur, as
appropriate. A standard fluid levelling gate 150 is also provided
downstream of main body 104 to maintain a minimum fluid level in
treatment zone 112.
As best shown in FIGS. 4 and 5, each radiation source module 148
includes a radiation source support leg 160, a horizontal support
and guide member 164 (optional), a connector box 172 and one or
more radiation source assemblies 176 adjacent the lower extremity
of support leg 160. Each radiation source assembly 176 includes a
high intensity radiation source 180 which is mounted within a
hollow sleeve 184 by two annular inserts 188. Of course, it will be
apparent to those of skill in the art that in some circumstances
radiation sources assemblies 176 will not require a sleeve and
radiation source 180 may be placed directly in the fluid to be
treated.
Each sleeve 184 is closed at the end distal support leg 160 and is
hermetically joined to a mounting tube 192 connected to support leg
160. The hermetic seal between sleeve 184 and mounting tube 192 is
accomplished by inserting the open end of sleeve 184 into a mount
196 which is
hermetically fastened to the end of mounting tube 192. A rubber
washer-type stopper 200 is provided at the base of mount 196 to
prevent sleeve 184 from breaking due to it directly contacting
housing 196 as it is inserted. A pair of O-ring seals 204, 208 are
placed about the exterior of sleeve 184 with an annular spacer 206
between them.
After sleeve 184, O-ring seals 204, 208 and annular spacer 206 are
inserted into mount 196, an annular threaded screw 212 is placed
about the exterior of sleeve 184 and is pressed into contact with
mount 196. The threads on screw 212 engage complementary threads on
the interior of mount 196 and screw 212 is tightened to compress
rubber stopper 200 and O-ring seals 204 and 208, thus providing the
desired hermetic seal.
The opposite end of each mounting tube 192 is also threaded and is
mated to a screw mount 216 which is in turn welded to support leg
160. The connections between mounting tube 192 and screw mount 216
and between screw mount 216 and support leg 160 are also hermetic
thus preventing the ingress of fluid into the hollow interior of
mounting tube 192 or support leg 160.
Each radiation source 180 is connected between a pair of electrical
supply conductors 220 which run from connector box 172 to radiation
source 180 through the inside of support leg 160 and mounting tube
192.
As best shown in FIGS. 4 and 5, a cleaning assembly 224 is also
included on each radiation source assembly 176 and mounting tube
192. Each cleaning assembly 224 comprises a cylindrical sleeve 228
which acts as a double-action cylinder. Cylindrical sleeve 228
includes an annular seal 232, 234 at each end of the sleeve. Seal
232, which is adjacent support leg 160, engages the exterior
surface of mounting tube 192 while seal 234, which is distal
support leg 160, engages the exterior surface of radiation source
assemblies 176.
The exterior of mount 196 includes a groove in which an O-ring seal
236 is placed. O-ring seal 236 engages the inner surface of
cylindrical sleeve 228 and divides the interior of cylindrical
sleeve 228 into two chambers 240 and 244. Chamber 240 is connected
to conduit 248 and chamber 244 is connected to conduit 252. Each of
conduits 248 and 252 run from connector box 172, through the
interior of support leg 160 and through the interior of mounting
tube 192, to mount 196 where they connect to chambers 240 and 244,
respectively.
As will be readily understood by those of skill in the art, by
supplying pressurized hydraulic oil, air or any suitable fluid to
chamber 240 through conduit 248, cylindrical sleeve 228 will be
urged toward support leg 160 and will force fluid out of chamber
244 and into conduit 252. Similarly, by supplying pressurized fluid
to chamber 244 through conduit 252, cylindrical sleeve 228 will be
urged toward sleeve 184 and will force fluid out of chamber 240 and
into conduit 248.
Conduit 252 is connected to a supply of an appropriate cleaning
solution, such as an acidic solution, and conduit 248 is connected
to a supply of any suitable fluid, such as air. Thus, when it is
desired to clean the exterior of sleeve 184, pressurized cleaning
solution is supplied to chamber 244 while fluid is removed from
chamber 240. Cylindrical sleeve 228 is thus forced to an extended
position distal from support leg 160 and, as cylindrical sleeve 228
moves to its extended position, seal 234 could also sweep loose
foreign materials from sleeve 184.
When the cylindrical sleeve 228 is in its extended position, the
cleaning solution in chamber 244 is brought into contact with the
exterior of radiation assemblies 176, which forms the interior wall
of chamber 244, and the cleaning solution chemically decomposes
and/or removes the remaining foreign materials which are fouling
radiation assemblies 176. After a preselected cleaning period,
fluid is forced into chamber 240, the pressure on the cleaning
solution is removed from chamber 244 thus forcing cylindrical
sleeve 228 to a retracted position adjacent support leg 160. As
cylindrical sleeve 228 is retracted, seal 234 again could sweep
loosened foreign materials from the surface of radiation assemblies
176.
As will be understood by those of skill in the art, the
above-described cleaning assembly 224 may be operated on a regular
timed interval, for example once a day or, where the quality of the
fluid being treated varies, in response to variations in the
readings obtained from radiation sensor 152.
Each radiation source module 148 can be mounted to main body 104 by
horizontal support member 164 which has a predefined
cross-sectional shape and which is received in a
complementary-shaped bore 256 in main body 104. The predefined
shape is selected to allow easy insertion of horizontal support
member 164 into bore 256 while preventing rotation of horizontal
support member 164 within bore 256.
As can been seen in FIGS. 3 and 4, the length of horizontal support
member 164 is selected such that horizontal support member 164
extends from support leg 160 to a greater extent than does
radiation source assembly 176. In this manner, radiation source
assembly 176 is maintained well clear of the inlet or outlet
transition regions as the radiation source module 148 is being
installed. This arrangement mimimizes the possibility of damage
occurring to the radiation source assembly 176 from impacting it
against other objects while installing radiation source module 148
and this is especially true if fluid is flowing through system 100.
Due to the resulting required length of horizontal supports 164,
bores 256 are horizontally staggered on opposite faces of main body
104.
When horizontal support member 164 is fully seated within bore 256,
electrical power connectors 264, cleaning solution connectors 268
and fluid connectors 272 on connection box 172 are brought into
engagement with complementary connectors on an enclosure 276. The
engagement of connectors 264 and 272 with the complementary
connectors on enclosure 276 also serves to maintain horizontal
support member 164 within bore 256. Enclosure 276 may conveniently
contain ballasts to supply electrical power for radiation sources
180 and pumps and storage vessels (not shown) for cleaning fluid
and pressurized fluid for cleaning assemblies 224.
Recent improvements in radiation source technology have now made
radiation sources of greater intensity available and devices which
are filamentless are available. In comparison, prior art UV lamps
employed in fluid treatment systems had rated outputs in the order
of 1 watt per inch and were five feet in length.
As these greater intensity radiation sources emit more radiation,
fewer radiation sources are needed to treat a given amount of
fluid. As is known to those of skill in the art, the dosage of
radiation received by the fluid is the product of the radiation
intensity and the exposure time. The intensity of the radiation
varies with the square of the distance the radiation passes
through, but the exposure time varies linearly with the fluid flow
velocity. Accordingly, it is desired to maintain the fluid to be
treated as close as possible to the radiation sources. This
requires either many low intensity radiation sources arranged
within a large treatment area or fewer high intensity radiation
sources arranged within a smaller treatment area For reasons of
efficiency, minimizing expense and for mitigating the
above-mentioned requirement of accurately controlling fluid level,
the latter alternative has been adopted by the present inventor as
described above. Irradiation zone 144 is designed to present a
closed cross-section to the fluid flow thereby ensuring that the
fluid to be treated passes within a predetermined maximum distance
of a minimum number of high intensity radiation sources 180. The
flow rate of fluid through irradiation zone 144 can be increased so
that an acceptable rate of fluid treatment is maintained with a
minimum number of high intensity radiation sources.
Thus, the present system has been designed to minimize the size of
irradiation zone 144 while elevating the fluid flow velocity to
obtain the desired rate of treatment. Thus, the flow rate through
irradiation zone 144 is higher than in prior an treatment devices
which are typically designed to operate at flow rates of 2 feet per
second or less. In contrast, the present system may be operated at
a flow rate through irradiation zone 144 of up to 12 feet per
second.
As is known to those of skill in the art, pressure head losses
through a fluid conduit are a function of the square of the fluid
flow velocity. Thus, high flow velocities result in increased head
loss and may result in unacceptable fluctuations in the fluid level
in the treatment system. Accordingly, the present system may be
provided with inlets and outlets having large cross-sections to
minimize head losses and to facilitate insertion and removal of
radiation source modules as will be discussed below. The actual
irradiation zone 144 is a relatively short length of reduced
cross-section and is connected to the inlets and outlets by
respective transition regions. In this manner, a desired relatively
high flow rate through the irradiation zone 144 may be accomplished
and hydraulic head losses minimized.
Other advantages provided by the present invention include
simplified maintenance, as the radiation source assemblies may be
cleaned of fouling materials in situ, and relatively easy removal
of radiation source modules for maintenance or radiation source
replacement. Further, the capability of in situ cleaning minimizes
or eliminates the requirement for otherwise redundant radiation
sources to be provided to replace those removed for cleaning and it
is contemplated that the elevated velocity of the fluid through the
irradiation zone will reduce the mount of fouling materials which
adhere to the radiation sources.
Another embodiment of a radiation source module 148B and a cleaning
assembly 300 is shown in FIGS. 6 and 7 wherein like components of
the previous embodiment are identified with like reference
numerals. As most clearly shown in FIG. 7, sleeve 184 is
hermetically scaled to mounting tube 192 at housing 196 in a manner
very similar to the embodiment shown in FIG. 5. However, in this
embodiment cleaning assembly 300 comprises a web 304 of cleaning
rings 308 and a pair of double-action cylinders 312,314. Each
cleaning ring 308 includes an annular chamber 316 adjacent the
surface of sleeve 184 and cleaning rings 308 are swept over sleeves
184 by the movement of cylinders 312,314 between retracted and
extended positions.
As with the embodiment shown in FIG. 4, conduits 320 and 324 run
from connector box 172 (not shown) through support leg 160 to
cylinders 312 and 314 respectively. When fluid is supplied under
pressure through conduit 320 to cylinder 312, the cylinder's piston
rod 328 is forced out to its extended position. As will be
understood by those of skill in the art, as piston rod 328 is
extended by the supply of fluid to the chamber 332 on one side of
the piston 336, fluid is forced out of the chamber 340 on the
second side of the piston 336 and passes through connector link 344
to chamber 348 of cylinder 314 forcing its piston rod 328 to also
extend and the fluid in chamber 352 to be forced into conduit
324.
In order to ensure that piston rods 328 travel synchronously,
cylinders 312 and 314 are designed such that the volume of fluid
displaced per unit of stroke of piston 336 in cylinder 312 is equal
to the volume of fluid received per unit of stroke of piston 336 in
cylinder 314. As will be understood by those of skill in the art,
this is accomplished by selecting appropriate diameters for each of
the two cylinders or the cylinder rods. As will be further
understood by those of skill in the art, an one way compensator
valve 356 is employed at the end of the extended stroke of the
pistons 336 to further compensate for the any difference in the
total volume of fluid which may result between chambers 332 and 352
and between chambers 348 and 340.
In a similar fashion, to retract piston rods 328, pressurized fluid
is supplied to conduit 324 and a second compensator valve 356 is
employed to compensate for the any difference in the total volume
of fluid which may result between chambers 332 and 352 and between
chambers 348 and 340 at the end of the retraction stroke.
It is contemplated that annular chambers 316 will be filled with a
predetermined quantity of suitable cleaning fluid which could be
changed at appropriate maintenance intervals, such as when
servicing the radiation sources. Alternatively, annular chambers
316 could be supplied with cleaning solution via conduits run
through the hollow center of piston rods 328. Another alternative
is to provide annular chambers 316 in a sealed configuration to
contain cleaning fluid which can be replaced when necessary.
Further, the cleaning solution could be circulated through hollow
piston rods 328, chamber 332 and annular chambers 316. By providing
appropriate baffling means (not shown) within annular chambers 316,
the cleaning fluid could enter through the lowermost hollow piston
rod 328, circulate through cleaning rings 308 and exit through
uppermost hollow piston rod 328.
While FIGS. 4, 5 and 6 illustrate specific embodiments of the
aspect of the invention relating to cleaning apparatus for a
radiation source assembly, other designs will be apparent to those
of skill in the an without departing from the spirit of the
invention.
For example, it is possible to employ a single, double-action
cylinder in combination with a hollow cylinder rod that is very
rigidly mounted through its cylinder rods on a plurality (e.g. 2 or
4) of cleaning rings 308. Further, it is possible to pump cleaning
fluid (e.g. water) through hollow piston rods toward and into
annular chambers 316 while moving the cylinder back and forth. If
annular chambers 316 were outfit with suitable spray nozzles or the
like, it would possible to apply a spray or jet stream across the
surface of the irradiation chamber thereby facilitating cleaning of
sleeve 184 of the radiation source.
Another design modification involves prefilling annular chambers
316 with a suitable cleaning fluid and modifying the chambers to
provide a closed wiping assembly. This would allow for the use of
various translation means to move the annular chambers 316 back and
forth over sleeve 184 of the radiation source. For example, it is
possible to utilize a double-acting, single cylinder that merely
translates annular chambers 316 back and forth over sleeve 184 of
radiation source. Of course it will be apparent to those of skill
in the art that the annular chambers should be mounted rigidly to
the translation means to avoid jamming of the entire assembly
resulting in damage to sleeve 184.
As will be further apparent to those skilled in the art, in the
embodiments described above, it is possible to reverse relative
movement between the radiation source and the cleaning mechanism.
Thus, the cleaning mechanism could be mounted rigidly with the
treatment zone in the present or any other system, and the
radiation source would be translated back and forth with respect
thereto.
Another preferred embodiment of the present invention is shown in
FIG. 8. In this embodiment a treatment system 400 includes a main
body 404 with a lower surface which, with a base wall 406, defines
a treatment zone 408. Treatment zone 408 comprises an inlet
transition region 412, a first irradiation zone 416, an
intermediate zone 420, a second irradiation zone 424 and a tapered
outlet zone 426. As is apparent from the Figure, outlet zone 426 is
lower than inlet zone 412 to provide some additional hydraulic head
to the fluid being treated to offset that lost as the fluid flows
through the treatment system. It will be apparent to those of skill
in the art that, in this configuration, the requirement for level
controlling gates and the like is removed as the treatment zone 408
also performs this function through the positioning of its inlet
and outlet.
Main body 404 could also include bores 430 to receive vertical
support members 434 of radiation source modules 438. Radiation
source modules 438 are similar to the above described radiation
source modules 148 but are configured for vertical positioning of
the radiation source assemblies 442. Radiation source assemblies
442 include sleeves 446 which are connected to mount stubs 450. Of
course, as mentioned above, it will be understood that in some
circumstances the radiation source assemblies 442 will not require
a sleeve and may instead be placed directly in the fluid to be
treated.
As mount stubs 450 are located above the maximum level of fluid in
treatment system 400, the connection to sleeves 446 need not be
hermetically sealed and may be accomplished in any convenient
fashion. Of course, as the connection point between sleeves and
mount stubs 450 is above the level of fluid within the system, the
interior of sleeves 446 will not be exposed to fluid.
Mount stubs 450 are in turn connected to support arms 454 which are
attached to vertical support members 434. Radiation sources 458 are
located within sleeves 446 and are connected between electrical
supply lines (not shown) which are run from connectors 462, through
hollow support arms 454 and mount stubs 450 and into sleeve 446.
Connectors 462 connect with complementary connectors on enclosure
466 which may include a suitable power supply and/or control means
for proper operation of the radiation sources 180 and cleaning
supply systems, if installed.
In this embodiment, service of on source modules 438 is
accomplished by lifting the radiation source modules 438 vertically
to remove them from the fluid flow. While not illustrated in FIG.
8, it is contemplated that in some circumstances the cleaning
assemblies described above will be desired and it will be apparent
to those of skill in the art that either of the cleaning assembly
embodiments described herein, or their equivalents, can be
favourably employed with this embodiment of the present invention.
Alternatively, it is contemplated that when the sleeves 446 require
cleaning, a radiation source module may simply be removed by
lifting it vertically.
As described above, fluid treatment systems typically include a
radiation sensor 152 to monitor the intensity of radiation within
an irradiation zone. These sensors include a radiation transmissive
window behind which the sensor proper is mounted and the window is
inserted into the fluid flow. Of course, as with radiation source
assemblies 176 (442), this window becomes fouled over time.
FIG. 9 illustrates radiation sensor assembly 500 in accordance with
another aspect of the present invention. Sensor assembly 500
includes a cylindrical body 502 in which a bore 504 is formed. A
radiation sensor element 508 is located at the interior wall of
bore 504 adjacent to a rod 512 which is radiation transmissive and
which extends from a front face plate 514 attached to body 502.
Sensor element 508 is hermetically sealed from fluid by O-rings 516
which are adjacent sensor element 508 and by O-ring 520 which
surrounds rod 512 at the connection point between front face plate
514 and body 502. The electrical leads 524 from sensor element 508
exit the rear of body 502 through bore 528.
Since the exposed end of rod 512 will become fouled over time, face
plate 514 also includes a cleaning jet 532. Cleaning jet 532 is
hermetically connected to bore 536 with O-ring 538, through body
502, which is in turn connected to a supply of pressurized cleaning
fluid (not shown) such as an acidic solution, water or air.
When pressurized cleaning fluid is pumped applied to bore 536,
cleaning jet 532 directs the cleaning fluid onto the exposed
surfaces of rod 512 to remove fouling materials. To prevent damage
to cleaning jet 532, rod 512 and to streamline fluid flow, a shroud
is also provided.
Radiation sensor assembly 500 may be mounted in a sleeve connected
to the treatment zone of a fluid treatment system as will be
apparent to those of skill in the art. Radiation sensor assembly
500 can be maintained within such a sleeve by a set screw (not
shown) which is received in keyway 540. Of course, as is known by
those of skill in the art, for accurate results it is desired that
rod 512 be orientated substantially perpendicular to the radiation
sources 180 being monitored.
It is contemplated that in normal use, radiation sensor assembly
500 will be cleaned by supplying a predetermined amount of cleaning
solution or water at predefined time intervals, to cleaning jet
532.
It should be understood that, while exemplary embodiments of the
present invention have been described herein, the present invention
is not limited to these exemplary embodiments and that variations
and other alternatives may occur to those of skill in the art
without departing from the intended scope of the invention as
defined by the attached claims.
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