U.S. patent application number 10/171911 was filed with the patent office on 2003-12-18 for cellular microbead filter for use in water recirculating system.
This patent application is currently assigned to Cornell Research Foundation, Inc.. Invention is credited to Timmons, Michael B..
Application Number | 20030230246 10/171911 |
Document ID | / |
Family ID | 29732886 |
Filed Date | 2003-12-18 |
United States Patent
Application |
20030230246 |
Kind Code |
A1 |
Timmons, Michael B. |
December 18, 2003 |
CELLULAR MICROBEAD FILTER FOR USE IN WATER RECIRCULATING SYSTEM
Abstract
A water recirculating system for use in producing fish. The
water recirculating system includes a fish raising tank that
provides an environment for fish to grow and a supply system to
deliver contaminated water from the fish raising tank to a
filtration system. The filtration system includes a chamber with a
hydraulic loading area that is divided into a plurality of cells
with smaller hydraulic loading areas. Filter media is positioned in
each cell to filter the contaminated water received from the fish
raising tank. A delivery system returns the filtered water back to
the fish raising tank.
Inventors: |
Timmons, Michael B.;
(Ithaca, NY) |
Correspondence
Address: |
SCHWEGMAN, LUNDBERG, WOESSNER & KLUTH, P.A.
P.O. BOX 2938
MINNEAPOLIS
MN
55402
US
|
Assignee: |
Cornell Research Foundation,
Inc.
|
Family ID: |
29732886 |
Appl. No.: |
10/171911 |
Filed: |
June 14, 2002 |
Current U.S.
Class: |
119/226 |
Current CPC
Class: |
A01K 63/045
20130101 |
Class at
Publication: |
119/226 |
International
Class: |
A01K 063/04 |
Claims
What is claimed is:
1. A filtration system comprising: a chamber that includes a
hydraulic loading area divided into a plurality of cells with
smaller hydraulic loading areas; and filter media positioned in
each of the cells to filter water passing through the cells.
2. The filtration system of claim 1 wherein the water is unable to
flow between cells as the water passes through the microbeads.
3. The filtration system of claim 1 wherein the filter media is
spherical microbeads with diameters between 1 mm and 3 mm.
4. The filtration system of claim 3 wherein the microbeads have a
density that is between 8 kg/cubic meter and 48 kg/cubic meter.
5. The filtration system of claim 1 wherein the microbeads within
each cell have a depth between 15 cm and 60 cm.
6. The filtration system of claim 1 wherein the chamber has a
rectangularly-shaped hydraulic loading area as water passes through
the filer media and each cell has a square-shaped hydraulic loading
area.
7. The filtration system of claim 1 wherein each cell has a
hydraulic loading area less than 2.3 square meters.
8. A filtration system comprising: a chamber that includes a
hydraulic loading area divided into a plurality of cells such that
each cell has a hydraulic loading area less than 2.3 square meters;
and microbeads positioned in each cell to filter water passing
through the chamber, the microbeads being spherical and having
diameters between 1 mm and 3 mm.
9. The filtration system of claim 8 further comprising a plurality
of nozzles positioned above the filter media within the chamber to
supply water to each cell in the chamber.
10. The filtration system of claim 8 wherein the microbeads have a
density that is between 8 kg/cubic meter and 48 kg/cubic meter and
the microbeads within each cell have a depth that is between 15 cm
and 60 cm.
11. The filtration system of claim 8 wherein the hydraulic loading
area of the chamber is rectangularly-shaped and the hydraulic
loading area of each cell is square-shaped.
12. The filtration system of claim 8 further comprising a receiving
tank to receive water from the chamber.
13. The filtration system of claim 12 wherein the chamber is at
least partially immersed in the receiving tank.
14. The filtration system of claim 8 wherein the water in each cell
is isolated from the water in the other cells as the water flows
through the microbeads.
15. A filtration system for use in a water recirculating system,
the filtration system comprising: a chamber that includes a
hydraulic loading area divided into a plurality of cells such that
each cell has a hydraulic loading area less than 2.3 square meters;
microbeads positioned in each cell to filter water passing through
the chamber, the microbeads being spherical and having diameters
between 1 mm and 3 mm, wherein the microbeads have a density that
is between 8 kg/cubic meter and 48 kg/cubic meter and the
microbeads within each cell have a depth between 15 cm and 60 cm; a
plurality of nozzles positioned above the microbeads within the
chamber to supply contaminated water to each cell in the chamber;
and a receiving tank for holding filtered water received from the
chamber, the chamber being at least partially immersed in the
receiving tank.
16. The filtration system of claim 15 wherein the water in each
cell is isolated from the water in the other cells as the water
flows through the microbeads.
17. The filtration system of claim 15 further comprising an air
passage positioned above the filter media to pass air by the water
to strip carbon dioxide from the water.
18. The filtration system of claim 15 wherein the microbeads are
polystyrene.
19. The filtration system of claim 15 wherein the chamber includes
8 cells.
20. The filtration system of claim 15 wherein each cell has a
perimeter greater than 6 meters.
21. The filtration system of claim 15 wherein the chamber has a
hydraulic loading area greater than 4.6 square meters at a location
where water passes through the filter media.
22. A water recirculating system for use in producing fish
comprising: a fish raising tank for holding water that provides an
environment for fish to grow; a supply system to deliver
contaminated water from the fish raising tank; a filtration system
that includes a chamber with a hydraulic loading area that is
divided into a plurality of cells with smaller hydraulic loading
areas and filter media positioned in each cell to filter water
received from the supply system; and a delivery system that
transports filtered water from the filtration system back to the
fish raising tank.
23. The water recirculating system of claim 22 wherein the
filtration system includes a plurality of nozzles positioned above
the filter media within the chamber to supply contaminated water to
each cell in the chamber.
24. The water recirculating system of claim 22 wherein the
filtration system includes a receiving tank for storing filtered
water received from the chamber, the chamber being at least
partially immersed in the receiving tank.
25. The water recirculating system of claim 22 wherein the
hydraulic loading area in each cell is isolated from the hydraulic
loading area in the other cells such that water does not flow
through filter media in more than one cell.
26. The water recirculating system of claim 22 wherein the filter
media is spherical microbeads with a diameter between 1 mm and 3 mm
and a density that is between 8 kg/cubic meter and 48 kg/cubic
meter, the microbeads within each cell having a depth between 15 cm
and 60 cm.
27. The water recirculating system of claim 22 wherein each cell
has a hydraulic loading area less than 2.3 square meters.
28. The water recirculating system of claim 22 wherein the delivery
system that transports filtered water from the filtration system to
the fish raising tank is a pumping system.
29. The water recirculating system of claim 22 wherein the fish
raising tank is a pond.
30. A method of recirculating water for use in a fish raising tank,
the method comprising: delivering contaminated water from the fish
raising tank to a filtration system that includes a chamber with a
hydraulic loading area that is divided into a plurality of cells
with smaller hydraulic loading areas; filtering the contaminated
water using filter media positioned in each cell to produce
filtered water; and delivering filtered water from the filtration
system back to the fish raising tank.
31. The method of claim 30 wherein filtering the contaminated water
using filter media includes filtering the contaminated water using
spherical microbeads with diameters between 1 mm and 3 mm and a
density between 8 kg/cubic meter and 48 kg/cubic meter.
32. The method of claim 30 wherein delivering contaminated water
from the fish raising tank includes delivering contaminated water
to a plurality of nozzles positioned above the filter media within
the chamber and uniformly dispersing the contaminated water over
the filter media.
33. The method of claim 30 further comprising stripping carbon
dioxide from the contaminated water.
34. The method of claim 30 wherein filtering the contaminated water
using filter media includes supplying heterotropic bacteria living
on the filter media with fine organic solids in the contaminated
water resulting in water polishing.
35. A method of improving capacity in a filtration system that
includes microbeads floating in chamber, the method comprising
dividing a hydraulic loading area of the chamber into cells with
hydraulic loading areas that are smaller than the hydraulic loading
area of the chamber.
36. The method of claim 34 wherein dividing the hydraulic loading
area of the chamber into cells includes dividing the hydraulic
loading area of the chamber such that water does not flow through
microbeads in more than one cell.
Description
TECHNICAL FIELD
[0001] This application relates generally to filtration systems
and, more particularly, to a water recirculating system for use in
producing fish.
BACKGROUND
[0002] Raising fish in water recirculating systems requires
nitrification treatment systems that maintain acceptable levels of
ammonia and nitrite within a water supply. A water recirculating
system needs to be able to oxidize an ammonia load that is
generated by fish as a result of daily fish feedings.
[0003] FIG. 1 illustrates one type of prior art filtration system
10 that maybe used in a water recirculating system. The filtration
system 10 includes a chamber 12 that contains microbeads 14.
Microbeads 14 are sufficiently buoyant such that they float on top
of filtered water 16 that collects in the bottom of chamber 12. The
microbeads 14 on the bottom are partially submerged in filtered
water 16 because they support the weight of the microbeads 14
located above them.
[0004] Contaminated water 18 is delivered to filtration system 10
from a number of potential sources, including fish raising tanks
where the water supply is contaminated with unsatisfactorily high
ammonia loads. Contaminated water 18 is supplied to chamber 12 from
above microbeads 14 using any method that uniformly distributes
contaminated water 18 over microbeads 14, such as nozzles 13
arranged in a uniform pattern. Gravity forces contaminated water 18
downward through microbeads 14 where it collects in the bottom of
chamber 12. Contaminated water 18 applies a force to microbeads 14
as it impacts microbeads 14 such that contaminated water 18
submerges some additional microbeads 14. An exit pipe 20 circulates
filtered water 16 back to the contaminated water source.
[0005] Microbeads 14 provide a substrate for bacterial growth
during operation of filtration system 10. The bacteria on
microbeads 14 utilize the ammonia and nitrite as nutrients for even
further bacterial growth. The bacterial growth on microbeads 14
also tends to reduce the buoyancy of microbeads 14. Heterotropic
bacteria living on the same beads utilize fine organic solids as
nutrients for growth resulting in water polishing and general
improvement in water quality.
[0006] One disadvantage of using a system 10 that includes
microbeads 14 is that such systems are limited in size. In systems
with large chambers, the strong buoyancy of microbeads 14 causes
microbeads 14 to short circuit the flow of water through microbeads
14 in some areas of the chamber. Short circuiting the flow of water
through microbeads 14 inhibits the ability of the bacteria on
microbeads 14 to oxidize ammonia loads in the water passing through
microbeads 14.
[0007] The size limitations associated with conventional filtration
systems that include microbeads makes it necessary to utilize
several chambers when oxidizing commercial ammonia loads (e.g., 9
kilograms TAN per day) that are generated from commercial fish
feedings (e.g., 300 kilograms per day). The large number of
chambers that are required to handle commercial ammonia loads adds
unwanted expense to systems that include microbeads 14.
SUMMARY
[0008] A filtration system having a chamber with a hydraulic
loading area that is divided into a plurality of cells such that
each cell has a hydraulic loading area less than 2.3 square meters.
The system further includes a filter media, such as microbeads,
positioned in each cell to filter water passing through the
chamber. In some embodiments, the microbeads are spherical and have
diameters between 1 mm and 3 mm.
[0009] The size limitation of conventional microbead filter systems
is addressed by dividing the hydraulic loading area in a large
chamber into cells with smaller hydraulic loading areas. The
smaller hydraulic loading area through each cell promotes efficient
filtering by bacteria that grows on the microbeads in each
cell.
[0010] Another aspect relates to a water recirculating system for
use in producing fish. The water recirculating system includes a
fish raising tank that provides an environment for fish to grow. A
supply system, such as a pumping system, delivers water from the
tank to a filtration system. The filtration system includes a
chamber with a hydraulic loading area that is divided into a
plurality of cells with smaller hydraulic loading areas. Filter
media, such as microbeads, are positioned in each cell to filter
the water received from the supply system. A delivery system
returns the filtered water back to the tank.
[0011] These and other aspects, embodiments and features will
become apparent from the following description and the referenced
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a prior art filtration system that
includes microbeads.
[0013] FIG. 2 illustrates a water recirculating system.
[0014] FIG. 3 is a section view of a chamber in the water
recirculating system of FIG. 2 taken along line 3-3.
DETAILED DESCRIPTION
[0015] The following detailed description refers to the
accompanying drawings. In the drawings, like numerals describe
substantially similar components throughout the several views.
These embodiments are described in sufficient detail to enable
those skilled in the art to practice the present subject matter.
Other embodiments may be utilized and changes may be made. The
scope of the present subject matter is defined only by the appended
claims, along with the full scope of equivalents to which such
claims are entitled.
[0016] FIG. 2 illustrates one embodiment of a water recirculating
system 50 that includes a filtration system 52. Filtration system
52 includes a chamber 54 having a hydraulic loading area that is
divided into a plurality of cells 56A-H (see FIG. 3) with smaller
hydraulic loading areas. A filter media, such as microbeads 58, is
positioned in each of the cells 56A-H to filter water that passes
through the cells 56A-H.
[0017] As used herein, hydraulic loading area is a cross-sectional
area of a particular portion of the filtration system 52 that is
transverse to the flow of water through that particular portion. As
shown in FIG. 3, the hydraulic loading area in chamber 54 is equal
to dimension A multiplied by dimension B. In the sample embodiment
shown in FIG. 3, the hydraulic loading area of each cell is
dimension X multiplied by dimension Y (shown for cell 56H only).
The size of cells 56A-H may be the same, or varied, depending on
the application where filtration system 52 is being used.
[0018] Filtration system 52 may further include a plurality of
nozzles 60 positioned above microbeads 58 within chamber 54. A
supply system 57 may be used to transport contaminated water from a
water source, such as a fish raising tank 55. The contaminated
water is supplied to nozzles 60 for uniform distribution above each
cell 56A-H in chamber 54. In some embodiments, the supply system is
a pumping system.
[0019] Chamber 54 is at least partially immersed in a receiving
tank 62 that holds filtered water after it passes through
microbeads 58. A delivery system 64 circulates the water back to
fish raising tank 55. In some embodiments, delivery system 64 is a
pumping system and fish raising tank 55 is a pond.
[0020] In one example embodiment, the water in each cell 56A-H is
isolated from the water in the other cells 56A-H as the water flows
through microbeads 58. In such example embodiments, the water is
unable to flow between cells 56A-H as the water passes through
microbeads 58.
[0021] The microbeads may be polystyrene, or any other material
that adequately filters a particular contaminated water supply. In
some embodiments, microbeads 58 are spherical and have a diameter
between 1 mm and 3 mm. The density of each microbead may be between
8 kg/cubic meter and 48 kg/cubic meter. Although specific shapes,
sizes and properties are described for microbeads 58, it will be
appreciated by those of ordinary skill in the art that any
microbeads which are calculated to achieve the same purpose may be
substituted for the specific microbeads described herein.
[0022] In some embodiments, microbeads 58 are positioned within
each cell 56A-H such that microbeads 58 have a depth D between 15
cm and 60 cm. The depth D of microbeads 58 will depend on such
factors as the size of microbeads 58 and each cell 56A-H in
addition to the flow rate of the water through microbeads 58.
[0023] In the example embodiment shown in FIG. 3, chamber 54 has a
rectangularly-shaped hydraulic loading area as water passes through
microbeads 58 and cells 56A-H have either a square or
rectangularly-shaped hydraulic loading area. Each cell 56A-H may
have a hydraulic loading area less than 2.3 square meters and/or a
perimeter greater than 6 meters. In some embodiments, chamber 54
has a hydraulic loading area greater than 4.6 square meters while
each cell 56A-H has a hydraulic loading area less than 2.3 square
meters. Although specific shapes and sizes are shown and described
for chamber 54 and cells 56A-H, it will be appreciated by those of
ordinary skill in the art that chamber 54 and cells 56A-H may have
any shape and size that adequately functions in filtration system
52. In addition, the number of cells may vary to suit particular
applications.
[0024] Filtration system 52 may also include an air passage 64
positioned above microbeads 58. A fluid source 65 forces a fluid,
such as air, to pass by the water before it drops onto microbeads
58. Passing air by the water strips undesirable carbon dioxide from
the water before the water passes through microbeads 58. Carbon
dioxide is extremely soluble in water such the carbon dioxide
stripping may be necessary in some recirculating applications. In
some embodiments, fluid source 65 may be integrated with a
ventilation system of the building where filtration system 52 is
located.
[0025] Although specific embodiments have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that any arrangement which is calculated to achieve the
same purpose may be substituted for the specific embodiments shown.
This application is intended to cover a water recirculating system
in applications other than those related to fish raising, including
mining, municpal and home wastewater treatment, car washes, laundry
mats and other similar applications.
[0026] It is to be understood that the above description is
intended to be illustrative, and not restrictive. Combinations of
the above embodiments, and other embodiments will be apparent to
those of skill in the art upon reviewing the above description. The
scope of the present subject matter should be determined with
reference to the appended claims, along with the full scope of
equivalents to which such claims are entitled.
* * * * *