U.S. patent application number 12/570327 was filed with the patent office on 2010-02-04 for liquid filtration system.
This patent application is currently assigned to ROYAL ENVIRONMENTAL SYSTEMS, INC.. Invention is credited to Carsten Dierkes.
Application Number | 20100025313 12/570327 |
Document ID | / |
Family ID | 46330111 |
Filed Date | 2010-02-04 |
United States Patent
Application |
20100025313 |
Kind Code |
A1 |
Dierkes; Carsten |
February 4, 2010 |
Liquid Filtration System
Abstract
In some embodiments, a filtration system may include one or more
of the following features: (a) a housing having a bottom portion, a
middle portion coupled to the bottom portion and all upper portions
and a cap coupled to the upper portion, (b) a sediment storage area
within the bottom portion, (c) a separator area within the middle
portion, (d) a porous filter within the upper portion, (e) an
access hatch within the cap, (f) an inlet pipe for allowing storm
water within a middle chamber, (g) an outlet pipe for allowing
filtered water to be discharged from the filtration system, and (h)
a central pipe being a passageway through the porous filter.
Inventors: |
Dierkes; Carsten; (Munster,
DE) |
Correspondence
Address: |
NIKOLAI & MERSEREAU, P.A.
900 SECOND AVENUE SOUTH, SUITE 820
MINNEAPOLIS
MN
55402
US
|
Assignee: |
ROYAL ENVIRONMENTAL SYSTEMS,
INC.
Stacy
MN
|
Family ID: |
46330111 |
Appl. No.: |
12/570327 |
Filed: |
September 30, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12027092 |
Feb 6, 2008 |
7632403 |
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12570327 |
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11043379 |
Jan 26, 2005 |
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12027092 |
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Current U.S.
Class: |
210/170.03 ;
210/255; 210/470; 210/496 |
Current CPC
Class: |
C02F 1/281 20130101;
C02F 1/001 20130101; E03F 1/00 20130101; C02F 1/5236 20130101; C02F
2301/026 20130101; Y10T 29/49826 20150115; C02F 2103/001 20130101;
E03F 5/0404 20130101 |
Class at
Publication: |
210/170.03 ;
210/255; 210/496; 210/470 |
International
Class: |
C02F 1/28 20060101
C02F001/28; E03F 5/00 20060101 E03F005/00; C02F 1/62 20060101
C02F001/62 |
Claims
1-34. (canceled)
35. A stormwater treatment apparatus comprising: (a) a shaft having
a bottom, at least one sidewall and a top spaced from the bottom by
the at least one sidewall, and a stormwater inlet port formed
through the at least one sidewall at a predetermined distance above
the bottom; (b) an inlet pipe disposed in the inlet port and
oriented to produce a circular flow of stormwater within a portion
of the shaft located below the inlet port for facilitating
sedimentation of solid contaminants present in the stormwater; (c)
a pervious concrete filter dimensioned to abut the at least one
sidewall and is horizontally disposed within the shaft at a
location above the stormwater inlet port, the filter being modular
and porous; and (d) an outlet in the at least one sidewall located
above the level of the pervious concrete filter whereby stormwater
exiting the shaft must first pass through the filter.
36. The stormwater treatment apparatus as in claim 35 wherein the
shaft is cylindrical and the bottom includes a frusto-conically
shaped recess.
37. The stormwater treatment apparatus as in claim 35 wherein the
porous concrete filter contains at least one chemical additive for
adsorbing or precipitating a dissolved pollutant that may be
present in the stormwater.
38. The stormwater treatment apparatus as in claim 37 wherein the
chemical additive is selected from a group consisting of ferric
oxide, hydroxides and zeolite.
39. The stormwater treatment apparatus as in claim 35 wherein the
filter comprises first and second layers of pervious concrete
sandwiching at least one of an ion exchange or an ion adsorbing
medium therebetween.
40. The stormwater treatment apparatus as in claim 39 wherein the
ion adsorbing medium is selected from a group consisting of
limestone, expanded clay, or recycled concrete intermixed with iron
oxides, iron hydroxides and zeolite.
41. A filtration system, comprising: a modular housing having a
bottom portion, a middle portion stacked upon the bottom portion
and an upper portion stacked upon the middle portion, and a cap
coupled to the upper portion; a sediment storage area within the
bottom portion; a separator area within the middle portion; a
molded filter of porous concrete within the upper portion; and an
access hatch within the cap.
42. The filtration system of claim 41, wherein the porosity of the
filter becomes finer as water travels from a middle chamber to an
upper chamber.
43. A modular filter, comprising: a single layer of a plurality of
multi-shaped filter elements made of a porous concrete, pores
decrease in size in a flow direction in a continuous manner; and a
sealant to seal together the plurality of multi-shaped filter
elements.
44. The modular filter of claim 43, wherein the filter elements are
a combination of substantially shaped rectangular filter elements
and substantially sector shaped filter elements.
45. The modular filter of claim 43, wherein the filter elements
include an iron compound.
46. The modular filter of claim 43, wherein pores of the filter
elements absorb hydrocarbons and dissolved heavy metals.
47. The modular filter of claim 43, wherein the filter elements are
retained within a filtration system.
48. The modular filter of claim 47, wherein the filter elements are
retained in an upper portion of the filtration system.
49. The modular filter of claim 48, wherein the filter elements are
supported by supports.
50. The modular filter of claim 49, wherein at least one of the
supports is a beam support which extends across the upper portion
of the filtration system anchored into a wall.
51. The modular filter of claim 50, wherein at least one support is
a channel support which supports the filter elements.
52. The modular filter of claim 43, further comprising a handle
coupled to at least one of the filter elements.
53. The modular filter of claim 43, wherein pores of the filter
elements absorb dissolved heavy metals.
54. The modular filter of claim 43, wherein pores of the filter
elements absorb phosphates.
Description
I. CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a Continuation-in-Part of U.S.
patent application Ser. No. 11/043,379, filed on Jan. 26, 2005,
titled Filter Element for Water Loaded with Solid Particles and
Dissolved Toxic Substances and Purification System Equipped with
Said Filter Element, listing Carsten Dierkes as inventor, herein
incorporated by reference in its entirety.
II. FIELD OF THE INVENTION
[0002] Embodiments of the present invention generally relate to
fluid filtration systems. Particularly, embodiments of the present
invention relate to water filtration systems. More particularly,
embodiments of the present invention relate to filtration systems
for removing pollutants and other materials.
III. BACKGROUND
[0003] Surface runoff is a term used to describe the flow of water,
from rain, snowmelt, or other sources, over the land surface, and
is a major component of the water cycle. Runoff occurring on
surfaces before reaching a channel is also called a nonpoint
source. If a nonpoint source contains manmade contaminants, the
runoff is called nonpoint source pollution. A land area which
produces runoff draining to a common point is called a watershed.
When runoff flows along the ground, it can pickup soil contaminants
such as petroleum, pesticides (e.g., herbicides and insecticides),
or fertilizers becoming discharge or nonpoint source pollution.
[0004] Urbanization increases surface runoff, by creating more
impervious surfaces such as pavement and buildings, not allowing
percolation of the water down through the soil to the aquifer. It
is instead forced directly into streams or storm water runoff
drains, where erosion and siltation can be major problems, even
when flooding is not. Increased runoff reduces groundwater
recharge, thus lowering the water table and making droughts worse,
especially for farmers and others who depend on water wells.
[0005] When antlhropogenic contaminants are dissolved or suspended
in runoff the human impact is expanded to create water pollution.
This pollutant load can reach various receiving waters such as
streams, rivers, lakes, estuaries and oceans with resultant water
chemistry changes to these water systems and their related
ecosystems. Further, there is considerable surface runoff in
natural systems from animal wastes being entrained in runoff or
from natural sediment loading in the absence of human alteration of
the land. In underdeveloped countries the proportion of runoff
attributable to natural factors has greater dominance, principally
due to the lack of isolation of water supplies from potential
runoff carrying animal waste.
[0006] Environmental issues associated with runoff include the
impacts to surface water, groundwater, and soil through transport
of water pollutants to these systems. Ultimately these consequences
translate into human health risk, ecosystem disturbance, and
aesthetic impact to water resources. Some of the contaminants
creating the greatest impact to surface waters arising from runoff
are petroleum, substances, herbicides, and fertilizers.
Quantitative uptake by surface runoff of pesticides and other
contaminants has been studied since the 1960s, and early on contact
of pesticides with water was known to enhance phytotoxicity. In the
case of surface waters, the impacts translate to water pollution,
since the streams and rivers have received runoff carrying various
chemicals or sediments. When surface waters are used as potable
water supplies, they can be compromised regarding health risks and
drinking water aesthetics (e.g., odor, color, and turbidity
effects). Contaminated surface waters risk altering the metabolic
processes of the aquatic species they host; these alterations can
lead to death, such as fish kills, or alter the balance of
populations present. Other specific impacts are on animal mating,
spawning, egg and larvae viability, juvenile survival, and plant
productivity.
[0007] Storm water runoff from building roofs, parking lots,
roadways, etc., picks up contaminants harmful to the environment if
allowed to pass, untreated, into rivers, streams, aquifers and the
like. The EPA has data suggesting polluted storm water runoff is a
leading cause of impairment to the nearly 40% of surveyed U.S.
water bodies which do not meet water quality standards. Over land
or via storm sewer systems, polluted runoff is discharged, often
untreated, directly into local water bodies. The pollutants may
include solids including sand, gravel, grass, leaves, and the like.
It is also known storm water runoff can pickup various nutrients,
including phosphorous, potassium, and nitrates from lawn and
agricultural fertilizers and heavy metals, including cadmium, zinc,
copper, lead, nickel, chromium from metal building roofs, gutters,
downspouts, and the like. Storm water runoff from roadways and
parking lots include polycyclic, aromatic hydrocarbons from oils
and motor fuels. Of course, significant concentrations of solids
and dissolved pollutants should not be discharged to ground water
or open watercourses. Also, the introduction of this water into the
city sewer system is not desired, since a corresponding capacity
must be reserved in this sewer treatment facility for this
purpose.
[0008] In the case of groundwater, the main issue is contamination
of drinking water, if the aquifer is abstracted for human use.
Regarding soil contamination, runoff waters can have two important
pathways of concern. Firstly, runoff water can extract soil
contaminants and carry them in the form of water pollution to even
more sensitive aquatic habitats. Secondly, runoff can deposit
contaminants on relatively pristine soils. creating health or
ecological consequences.
[0009] Mitigation of adverse impacts of runoff can take several
forms: land use development controls aimed at minimizing impervious
surfaces in urban areas, erosion controls for farms and
construction sites; flood control programs; and chemical use and
handling controls in agriculture, landscape maintenance, industrial
use, etc.
[0010] Chemical use and handling has become a focal point mainly
since passage of NEPA (National Environmental Policy Act) in the
U.S. States and cities have become more vigilant in controlling the
containment and storage of toxic chemicals, thus preventing
releases and leakage. Methods commonly applied are: requirements
for double containment of underground storage tanks; registration
of hazardous materials usage; reduction in numbers of allowed
pesticides; and more stringgent regulation of fertilizers and
herbicides in landscape maintenance. In many industrial cases,
pretreatment of wastes is required to minimize escape of pollutants
into sanitary or storm water sewers.
[0011] The U.S. Clean Water Act (CWA) requires local governments in
urbanized areas (as defined by the Census Bureau) to obtain storm
water discharge permits for their drainage systems. Essentially
this means the locality must operate a storm water management
program for all surface runoff entering the municipal separate
storm sewer system. EPA and state regulations and related
publications outline six basic components each local program must
contain: public education (informing individuals, households,
businesses about ways to avoid storm water pollution); public
involvement (support public participation in implementation of
local programs); illicit discharge detection and elimination
(removing sanitary sewer or other non-storm water connections);
construction site runoff controls (e.g., erosion and sediment
controls); post-construction (i.e., permanent storm water
management controls; and pollution prevention and "good
housekeeping" measures (e.g., system maintenance). Other property
owners which operate storm drain systems similar to municipalities,
such as state highway systems, universities, military bases and
prisons, are also subject to the permit requirements.
[0012] Surface runoff is not the only contaminate. Industrial
process waters and contained water are polluted liquids providing
potential hazards to the environment. Natural made contaminates,
such as animal waste, also provide potential hazards to water
supplies.
[0013] For liquids, such as water, loaded with solid particles and
dissolved toxic substances, it is desirable to have a structurally
simple filter element, performing as a purification system, which
effectively removes the solid particles and particulate toxic
substances from the liquid without great expense.
IV. SUMMARY OF THE INVENTION
[0014] In some embodiments, a filtration system may include one or
more of the following features: (a) a housing having a bottom
portion, a middle portion coupled to the bottom portion and an
upper portion, and a cap coupled to the upper portion, (b) a
sediment storage area within the bottom portion, (c) a separator
area within the middle portion, (d) a porous filter within the
upper portion, (e) an access hatch within the cap, (f) an inlet
pipe for allowing storm water within a middle chamber, (g) an
outlet pipe for allowing filtered water to be discharged from the
filtration system, and (h) a central pipe being a passageway
through the porous filter.
[0015] In some embodiments, a filtration system may include one or
more of the following features: (a) a housing having a bottom
portion, a middle portion coupled to the bottom portion and an
upper portion, and a cap coupled to the upper portion, (b) a
sediment storage area within the bottom portion, (c) a separator
area within the middle portion, (d) a filter within the upper
portion, the filter being a molded body of porous concrete, (e) an
access hatch within the cap, (f) a water inlet opening into the
upper portion and a water outlet opening from the upper portion,
and (g) a pre-filter leading to the water inlet for leaves and
refuse.
[0016] In some embodiments, a storm water treatment apparatus may
include one or more of the following features: (a) a shaft having a
bottom, at least one sidewall and a top spaced from the bottom by
the at least one sidewall, and a storm water inlet port formed
through the at least one sidewall at a predetermined distance above
the bottom, (b) an inlet pipe disposed in the inlet port and
oriented to produce a circulatory flow of storm water within a
portion of the shaft located below the inlet port for facilitating
sedimentation of solid contaminants present in the storm water, (c)
a pervious concrete filter member dimensioned to abut the at least
one sidewall and is horizontally disposed within the shaft at a
location above the storm water inlet port, (d) an outlet in the at
least one sidewall located above the level of the pervious concrete
tilter member whereby storm water exiting the shaft must first pass
through the filter member, (e) an annular baffle overlaying the
frusto-conically shaped recess in the bottom of the shaft, and (f)
a cleanout passage extending from a location proximate the top to
the frusto-conical shaped recess.
[0017] In some embodiments, a method of constructing a filtration
system may include one or more of the following steps: (a) forming
a housing hating a bottom portion, a middle portion, an upper
portion, and a cap, (b) coupling the bottom portion having a
sediment storage area within the bottom portion to the middle
portion having a separator area within the middle portion, (c)
coupling the middle portion to the upper portion having a porous
filter within the upper portion, (d) coupling the upper portion to
the cap having an access hatch within the cap, and (e) forming an
inlet pipe for allowing storm water within a middle chamber.
[0018] In some embodiments, a method of constructing a filtration
system may include one or more of the following steps: (a) forming
a sediment storage area adjacent a bottom of a housing, (b)
locating a separator area above the sediment storage area and below
a porous filter, (c) coupling a cap having an access hatch above
the porous filter, (d) forming an outlet pipe for allowing filtered
water to be discharged from the filtration system, (e) traversing a
central pipe through the porous filter, and (f) inserting an inlet
pipe into the housing at an angle above the separator.
V. DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a sectioned, pictorial view of a storm water
filtration system constructed in accordance with an embodiment of
the invention;
[0020] FIG. 2 is a side cross-sectional view of an upstream sump
structure in an embodiment of the present invention;
[0021] FIG. 3 is side cutaway profile view of a filtration system
in an embodiment of the present invention;
[0022] FIG. 4 is a side view of a porous concrete filter and
overflow pipe which makes up internal components of a filtration
system in an embodiment of the present invention;
[0023] FIG. 5 is a top view of FIG. 4;
[0024] FIG. 6 is a view of a filter support beam in an embodiment
of the present invention;
[0025] FIG. 7 is a side view of the filter support beam shown in
FIG. 6;
[0026] FIG. 8 is a side sectional view of a cyclonic separator
portion of a filtration system in an embodiment of the present
invention.
[0027] FIG. 9 is a schematic depiction of filtration, adsorption
and precipitation processes within a filtration system's filter in
an embodiment of the present invention;
[0028] FIG. 10 shows a cross-sectional view of a purification
system in embodiments of the present invention;
[0029] FIG. 11 shows a cross-sectional view of a seepage pipe of a
purification system according to FIG. 10;
[0030] FIG. 12 shows a flow process diagram of a method of
constructing a filtration system in an embodiment of the present
invention.
VI. DESCRIPTION OF THE EMBODIMENTS
[0031] The following discussion is presented to enable a person
skilled in the art to make and use the present teachings. Various
modifications to the illustrated embodiments will be readily
apparent to those skilled in the art, and the generic principles
herein may be applied to other embodiments and applications without
departing from the present teachings. Thus, the present teachings
are not intended to be limited to embodiments shown, but are to be
accorded the widest scope consistent with the principles and
features disclosed herein. The following detailed description is to
be read with reference to the figures, in which like elements in
different figures have like reference numerals. The figures, which
are not necessarily to scale, depict selected embodiments and are
not intended to limit the scope of the present teachings. Skilled
artisans will recognize the examples provided herein have many
useful alternatives and fall within thee scope of the present
teachings. While embodiments of the present invention are discussed
in terms of a water runoff filtration system, it is fully
contemplated embodiments of the present invention could be used in
most any liquid filtration system without departing from the spirit
of the invention.
[0032] Embodiments of the present invention can have a cylindrical
housing built in modular sections, beginning with a lower portion
consisting of a "sump" section and a cyclonic separator section
stacked on top of the sump section. A upper portion of the
cylindrical housing carries a filter and other components as
described below. The upper portion can be stacked directly on top
of the separator section. It is closed at the top by a "cap"
section. These modular sections can be made of pre-cast concrete
and collectively create a single cylindrical unit.
[0033] The upper portion can include an inlet pipe, a filter
section, an outlet pipe, and a cleanout pipe extending into an
opening through the filter section. The top or "cap" section can
include an access hatch.
[0034] When the upper portion is mounted on top of the separator
section, the inlet can be positioned so it will deliver
contaminated water into a region between the cyclonic separator and
the filter or, in other words, above the separator but below the
filter. The contaminated water swirls around above the separator,
allowing heavier sediments to precipitate and drop down into the
sump section. The water pressure which drives the incoming flow
then forces the contaminated water to flow up (or "up-flow")
through the filter, thus further removing contaminants. After
passing up through the filter into a chamber above the filter, the
filtered water is discharged via the outlet pipe.
[0035] This system has several advantages over previous designs
from the standpoint of cost of installation and maintenance.
Previous systems have been expensive to build and maintain. The
modular system described above is easy to install. The cleanout
pipe permits easy and direct access to accumulated sediment or
sludge in the sump section by a maintenance person. It is located
so the maintenance person can open the access hatch and have
direct, line of sight access to the sump section for easily pumping
it clean via conventional mechanical suction devices.
[0036] The system disclosed here is designed so the filter may be
periodically cleaned by reverse flushing the filter with water,
thus driving accumulated contaminates backward from the filter.
During maintenance and cleanout, the maintenance person will
typically pump out the sump section, reverse flush the filter, and
then pump the sump section clean a second time.
[0037] The filter can be, made of porous concrete. Occasionally,
the filter itself will become fouled to the point where it can no
longer be adequately cleaned by reverse flushing. Alternatively,
there may be a need to change to a different type or porosity of
concrete filter designed to remove a different set of contaminants
or to operate at a different flow rate. To accommodate easy filter
replacement the filter can be installed in fitted sections
horizontally across the upper portion of the housing. This makes it
easy to install and remove an otherwise heavy and bulky concrete
filter. The sections are sealed together by conventional insulating
foam or the like. The cap section of the cylindrical housing may be
lifted entirely from the filter structure in order to provide
access to the filter for a replacement operation. The modular
filter is also designed to be installed or replaced through the
access opening in the center of the cap section. This can enhance
the long term maintainability (see FIG. 5).
[0038] While removal efficiencies will vary depending on the makeup
of the concrete filter, the filtration system described here is
capable of exceeding both North American and European pollutant
removal standards.
[0039] Referring now to the drawings, and first to FIG. 1, shown
generally at 10 is a storm water filtration system constructed in
accordance with an embodiment of the invention. The filtration
system 10 is primarily composed of a cylindrical housing 12, a
porous concrete filter 14 (further described later), a
hydrocyclonic or "cyclonic" separator 16, an inlet pipe 18 and an
outlet pipe 20. All pipes used in this system are conventional. The
cylindrical housing 12 and cyclonic separator 16 can be made from
pre-cast concrete sections, or the like, as will be further
described below. However, cyclonic separator 16 can be made of
other materials including, but not limited to, fiberglass,
polymers, or aggregate without departing from the spirit of the
invention.
[0040] As best shown in FIG. 3, the cylindrical housing 12 is made
up of one or more different modular sections 12A, 12B, 12C, 12D
vertically stacked one on top of the other. While FIG. 3 shows
cylindrical housing 12 made up of four modular sections, it is
fully contemplated cylindrical housing 12 could be made up of most
any number of modular sections without departing from the spirit of
the invention. Section 12A makes up the top, or upper, portion of
the cylindrical housing 12; section 12B is the middle; section 12C
is the bottom; and section 12D is a cap resting on section 12A and
closing the top of cylindrical housing 12.
[0041] Each of the three stacked sections 12A, 12B, and 12C may
vary in size. By way of example, for a system designed for use in
flow applications where treatment flow is, but not limited to, less
than 0.8 cubic feet per second, and peak flow is, but not limited
to, 2.0 cubic feet per second or less, the approximate dimensions
would be as follows: (1) the internal diameter of the cylindrical
housing can be 60.0 inches; (2) section 12C functions as a sediment
basin or sump and can have sufficient vertical height to create 24
inches of sump space below section 12B; (3) section 12B is the
cyclonic separator section and can have a vertical height of about
12 inches; and (4) section 12A can have a height of about 72
inches. The overall height of system 10 is approximately 10 feet.
While specific dimensions have been given above, it is fully
contemplated most any of these dimensions could be altered without
departing from the spirit of the invention. These dimensions could
change depending on the filtration specifications needed or as
stated above the treatment flow necessary for filtration system
10.
[0042] As indicated above, section 12C provides a sediment storage
area 22 and makes up the bottom portion of filtration system 10. It
can be sloped toward center-bottom to allow sediment to settle in
the center of the cylindrical housing 12 for cleanout purposes.
Section 12B rests directly above and on section 12C. It carries the
cyclonic separator 16. Likewise, section 12A rests on top of
section 12B. For systems designed out of concrete, all of these
sections 12, 12B, and 12C have annular shoulders on their tops and
bottoms (e.g., numerals 15, 17 in FIG. 3) so one can be stacked on
top of another at the installation site. Annular shoulders 15 and
17 can also have rubber gaskets to provide water tight sealing.
This configuration allows system 10 to be pre-cast in sections
elsewhere and then transported to a worksite for assembly and
installation. For systems where filtration system 10 is designed
out of other materials such as fiberglass, stainless steel, or
other polymers, sections 12A, 12B, and 12C may be made of one
section and may not require the use of annular shoulders or
gaskets.
[0043] The cap 12D, which rests directly on top of section 12A, has
an access hatch 24. The access hatch 24 normally remains closed
until a maintenance person needs to access the interior of the
system 10 after assembly, typically to clean out the sediment
storage area or slump 22. The seams where sections 12A, 12B, 12C
fall below the invert of the outlet pipe 20 can also be sealed as
needed for no leakage (e.g., with rubber gaskets 15, 17). Inlet
pipe 18 and all piping network prior to the treatment unit below
the invert elevation of the outlet pipe 20 will also be required to
be watertight and leak free. This helps to maintain an internal
water surface elevation not to extend below the invert of the
outlet pipe 20, thus ensuring the constant submersion of the filter
14 at all times.
[0044] When system 10 is in use, untreated or unfiltered water
enters the cylindrical housing 12 through inlet pipe 18. Inlet pipe
18 is located below porous concrete filter 14 and just above
cyclonic separator 16 to deliver water directly into a middle
chamber 26 above the separator 16.
[0045] After entering cylindrical housing 12, inlet pipe 18 turns
at an angle of about 90 degrees (e.g., 27 in FIG. 1). This directs
incoming water into a continually swirling action above cyclonic
separator 16. The funnel like shape of cyclonic separator 16,
combined with the swirling movement of the water; promotes the
separation of solid substances mixed in the incoming liquid.
Separated solids then drop into sediment storage area or sump 22
where the water is calm and the solids are likely to never
re-suspend until they are suctioned out through maintenance. FIG. 8
sets forth a more detailed illustration of cyclonic separator 16.
As indicated above, separator 16 can be composed of concrete,
fiberglass, stainless steel, or polymers and fashioned to have a
shallow, funnel-like shape. Cyclonic separator 16 may be molded as
part of the entire cylinder section 12B.
[0046] Unfiltered water can enter via inlet pipe 18 and eventually
fill the space below filter 14. Water can then be forced upward and
through filter 14 into an upper chamber 28. Concrete filter 14,
which will be described in greater detail below, serves as both a
physical and chemical filter removing contaminants from the water.
When the water in chamber 28 reaches a sufficiently high level
relative to outlet pipe 20, it is discharged from filter system
10.
[0047] As should be clear by now, system 10 cleans contaminated
water in two stages. The first stage involves the separation of
sediments by gravitation as water enters system 10 and swirls
around above cyclonic separator 16. The second stage involves
up-flow filtration through concrete filter 14.
[0048] FIG. 9 generally depicts how concrete filter 14 operates.
Porous concrete filters can be designed to allow different flow
rates through them. In this instance, porous filter 14 includes an
iron compound causing filter 14 to act as both a physical and
chemical filter.
[0049] The pores in the filter 14 partly serve to physically
separate contaminants from the water. as indicated generally at 30
in FIG. 9. In addition, contaminants like hydrocarbons and
dissolved heavy metals are adsorbed by the internal surfaces
created by pores through filter 14. This is generally indicated at
32. In addition, the iron compound in filter 14 buffers and
promotes chemical precipitation of some dissolved contaminants, as
indicated at 34.
[0050] A uniqueness about the design described here is it has a
physical design that is easy to assemble and maintain. Concrete
filter 14 is also easy to replace which will eventually become
necessary as the system 10 ages.
[0051] In this respect, FIG. 5 shows:, physically, porous concrete
filter 14 can be made up of several distinct filter pieces or
sections, 14A-14G. These sections are supported inside section 12A
by a framework of individual beam supports 36, 38 and channel side
supports 40, 42. FIGS. 6 and 7 illustrate top and side views of The
two beam supports 36, 38 extend across the inside of cylindrical
section 12A. Each end 44, 46 of each beam support is anchored to
the inside wall of section 12A. These supports 36, 38 have small
rectangular supports 48, 50, 52 provide horizontal shoulders upon
which filter sections 14A-14G rest. The two channel supports (one
on each interior side of section 12A) have similar supports 54, 56;
providing shoulders for filter sections 14A-14B and 14E-14F,
respectively.
[0052] As illustrated in FIG. 1, each filter section 14A-14G has a
handle 58 for installation and removal. During assembly of the
various components of system 10, the framework described above is
connected to the interior walls of section 12A and individual
filter sections are installed on the frameworks The filter sections
are bonded together with a conventional sealing foam when
installed, but may be easily broken or cut apart when and if it
becomes necessary to remove them.
[0053] As illustrated in the various Figures, the system 10
includes a central pipe 60 creating a passageways through filter
sections 14A-14G. The top of central pipe 60 is usually above the
invert of the outlet pipe 20. As reflected in the drawings, outlet
pipe 20 has an open "T" section 62 on the inside of cylindrical
housing 12 allowing filtered water to pass out through outlet pipe
20.
[0054] During normal operation, as water "up-flows" through filter
14, into upper chamber 28 above filter 14, the water level will
rise until the filtered water exits via outlet pipe 20. In
extraordinary situations, such as extreme flooding, more
contaminated water may enter the cylindrical housing 12 at a rate
higher than the maximum flow rate filter 14 can handle. In such
case, unfiltered water may eventually rise up and spill over the
top of central pipe 60 until incoming flow levels are reduced.
[0055] FIG. 2 illustrates a separate, upstream sump structure,
indicated generally at 64, for separating heavier sediments before
contaminated water enters the cylindrical housing 12. The
contaminated water enters inlet pipe 66 into a tank 68 formed in
sections 70. 72. much like cylindrical housing 12. The outlet pipe
74 of the upstream sump stricture 64 is connected to the inlet pipe
18 of cylindrical housing 12. The sump structure 64 also has an
access hatch 76 for clean-out purposes.
[0056] In another embodiment a filter element consists of a molded
body of porous or pervious concrete and is a portion of a
purification system as a body through which water flows. The molded
body of concrete can have a pore ratio of 15% to 35% volume. The
molded body can consist of a single grain-size concrete with a
filter grain-size of 0.25 to 4.0 m. The concrete can consist of
natural or synthetic aggregates at 85% to 89% by volume and 11% to
15% by volume of binder, In one embodiment a blast furnace cement,
for example CEM III/A according to DIN 1164-1 (Deutsches Institut
fur Normung), may be used. However, it is contemplated a suitable
organic resin may be used as the binding agent. Suitable cements
for embodiments of the present invention contain 35% to 64% by
weight Portland cement clinker, 36% to 65% by weight granulated
blast-furnace slag, as well as 0% to 5% by weight of conventional
secondary components. To increase the adsorption action of the
filter additives such as iron oxides and/or iron hydroxides
(Fe(OH).sub.2) can be further added to the concrete 1%-15% by
weight, especially 3% to 7% by weight, relative to the binder
content, Other suitable additives can be, in particular, Fe(III)
oxides such as goethite, Fe.sub.2O.sub.3xH.sub.2O and/or hematite
(Fe.sub.2O.sub.3). It is better for the adsorption characteristics
for the concrete to contain tip to approximately 10% by weight of
aluminum oxides Al.sub.2O.sub.3 and/or layered silicates. At least
one layer of porous concrete has a CaO content of 7% to 10% in the
molded body to provide a sufficiently higher pH-value for the
chemical precipitation of heavy metal ions.
[0057] According to an embodiment of the invention, the filter
element is part of a purification system, in which the filter is
arranged as a partition between a lower and an upper compartment of
a treatment chamber, wherein a water feed opens into the lower
compartment and a water outlet issues from the upper
compartment.
[0058] The filter action of the filter element, according to the
invention, is determined by the size and the design of the pores.
The dissolved toxic substances are removed through adsorption, ion
exchange, chemical precipitation, and/or chelation through a high
CaO portion in the cement. To assist in adsortion chemical
precipitation and chelation, the porous body has as large a surface
as possible, relative to its volume. So the vast majority of
particles are filtered out through the depth of the filter, the
porous nature of the filter lends to maximizing the surface contact
time of the pollutant to the filter. For example, the molded body
could have an increasing fine porosity in the direction of flow. If
the filter element has a modular design then individual filter
parts can be replaced as needed. Solid particles are deposited on
the filter element from below since the water to be purified in the
purification system is forced to pass the filter element in the
upward-flowing current. Thus, the filtered-out particles separate
from the filter element and sink when the vertical current
subsides. For this reason, the lower compartment can preferably be
formed as a sedimentation space. In order to separate out the solid
particles as effectively as possible, a hydro-cyclone baffle with
sludge trap below it can be arranged in a sedimentation space. In
order to activate the action of the hydro-cyclone, the water feed
is made to flow into the lower compartment in a tangential
manner.
[0059] The filter element made in accordance with embodiments of
the invention and the purification system according to embodiments
of the invention are suitable for removal of particulate and
dissolved heavy metal ions such as Cu, Pb, Zn, Cd, and Ni from
contaminated water, in particular rainwater flowing down from metal
roofs and transport surfaces.
[0060] For the water outlet from the treatment chamber, there are
different possibilities. Thus, the water outlet can be formed by
porous parts of the chamber wall. Alternatively or additionally, it
can be formed using a discharge pipe. In this case, the pipe is
preferably, but not necessarily, designed as a seepage pipe and
embedded in a water-permeable filter material. According to the
predictable water accumulation, several such pipes can also be
connected to the upper section of the treatment chamber in a
parallel-facing or star-shaped arrangement. In this way, an
infiltration trench system known in the art, may be formed for the
seepage of the filtered water.
[0061] The pipe, like the filter element, may consist of porous
concrete. It then acts as a second filter stage, which in like
manner as the first filter stage of the filter element, can filter
out toxic substances not collected by the first stage.
[0062] The purification system represented in FIG. 10 shows three
generally vertical shafts arranged in the ground which are
connected to each other via pipes. A first shaft 100 may serve as
the pre-filter. A second shaft 200 encloses the main elements of
the purification system. A third shaft 300 serves as the control
and rinsing shaft. The second shaft 200 may have a cylindrical tank
adapted to be buried in the ground and is preferably formed from
concrete, much like a manhole structure used in sewer systems. It
is also contemplated shaft 200 may be fabricated from a suitable
polymer, as discussed above. Shaft 200 includes a removable cover
at the ground surface so the cover can be readily removed to
provide access to the interior thereof for maintenance and repair
purposes.
[0063] The water to be purified enters, via a pipe 400, a chamber
500 of shaft 100 and via a pipe 700, a lower compartment 900 of a
treatment chamber 800 of shaft 200. Lower compartment 900 is
separated from an upper compartment 110 of treatment chamber 800 by
a filter element 102 having a modular design and arranged as a
generally horizontal partition. A water inlet 120 of pipe 700 opens
tangentially into lower compartment 900, so a swirling flow is
generated. A 90 degree elbow attached to the end of pipe 700 may be
used to promote a desired circular flow pattern. Arranged
approximately at the center of lower compartment 900 can be a
funnel-shaped element 130 with a central opening 140, which joins
together with tangential inlet 120 forms a cyclone separator. The
swirling flow provides a greater dwell time for non-floatable
solids passing through sieve 600 to settle out. Via central opening
140, solid matter precipitating in lower compartment 900 call fall
down into a sludge trap 150, from which it can be periodically
suctioned by a maintenance worker via a disposal pipe 160. While
disposal pipe 160 is shown as running along side filter element
102, it can also be designed to pass through filter element
102.
[0064] Filter element 102 can be constructed in a modular manner,
perhaps similar to the discussion above, from one or more plates
consisting of no-fine texture, porous concrete with a high portion
of CaO component in the cement; The lower plates in a stack of such
filter plates can have a more coarse porosity than the upper
plates. Through this, the smaller solid particles of the water to
be purified, which flows through filter element 102 in the up-flow
process, are not already retained at the underside of filter
element 102, but rather disperse in the deeper lying layers. The
purified water reaches upper compartment 110 flowing off from there
into a control and rinsing chamber 190 of control and rinsing shaft
300, via water outlet 170 and a pipe 180. Pipe 180 is designed as a
seepage pipe and displays the cross section shown in FIG. 11. Like
filter element 102, pipe 180 can consist of porous concrete, in
particular with a pH-reactive floor of 320. Due to this floor of
320, the pH value of the water is increased to a value of 7 to 9.
Pipe 180 of porous concrete is shown as being embedded in a
so-called "infiltration trench", filling 210 consisting of a
special filter material. This facilitates a large-surface
distribution of the water to be drained away. It is to be
understood several such pipes 180 can be connected to both the
upper compartment 110 of shaft 200 and to the control and rinsing
chamber 190. There local laws or regulations forbid the use of
infiltration trenches, the filtered rainwater runoff can flow out
from chamber 110, via non-porous pipe into a municipality's storm
water server system.
[0065] In order to be able to receive an unexpectedly high volume
and, if need be, to discharge it unpurified, an overflow pipe 220
is shown leading from pre-filter chamber 500 into upper compartment
10 of treatment chamber 800. In a corresponding manner an overflow
pipe 230 is connected to control and rinsing chamber 190, in order
to allow water unable to seep to be discharged.
[0066] As FIG. 10 shows, the water outlet 170 is arranged so filter
element 102 lies below the water line. Prevented through this is a
drying out of filter element 102, and in particular. a caking in
filter element 102 of solid particles such as clays, etc., which
would negatively influence the effectiveness of filter element 102
and its service life and ability to be rinsed. Water can also be
introduced, via treatment chamber 800, in order to back-rinse
filter element 102 from time to time. The particles loosened from
filter element 102 then sink into sludge trap 150. In this way,
material deposited in pipe 180 can also be rinsed into the control
and rinsing shaft 190.
[0067] In accordance with embodiments of the present invention,
filter element 102 can comprise a porous or permeable concrete
material made from gravel or stone, cement (or any other bonding
agent such as a synthetic resin), water, but little or no sand, and
crushed quartz has been found to serve well as the aggregate. This
mixture creates an open cell structure allowing; storm water to
filter through the porous concrete layers. Depending on the blend,
stone size, head pressure and the thickness of the plates, the
porous concrete filter element 102 can pass 15 to 25 gallons of
water per minute through its open cells for each square foot of
surface area also depending on the designed head pressure. It is
fully contemplated the filter element 102 could pass any amount of
water per minute based upon many factors such as the blend, stone
size, thickness of the plates, head pressure, and concrete without
departing from the spirit of the invention. As indicated, the
pervious concrete may have a void structure of 20% to 250%,
allowing water to readily pass through it at the rate indicated.
The efficiency of removal of pollutants decreases with increasing
pore size of the filter element 102 or increasing flow rate due to
an increased head pressure. Where heavy metal concentrations in the
storm water are low, a higher flow rate can be achieved using
filter plates having a larger pore size. With larger pore sizes and
medium-to-high metal concentrations in the storm water runoff,
additives placed in the filter element 102 may be used to achieve
sufficient cleaning capacity to meet applicable standards. The lime
naturally occurring in cement renders the filter material alkaline
and reacts with certain pollutants, such as phosphates, to
precipitate and/or adsorb dissolved contaminants so they ultimately
become entrapped in the filter element 102 or settle out into the
sedimentation trap 150 at the base of shaft 200.
[0068] Hydrocarbons tend to become entrained in the pores of filter
element 102. Chemical additives can be blended with the cement or
resin used in forming the porous concrete to address selected
target pollutants For example, Fe.sub.2O.sub.3 in powder form
having a particle size less than 1 micron may be added to cement
prior to its being nixed with aggregate and water to form the
porous concrete. The presence of the Fe.sub.2O.sub.3 has been found
to enhance the ability of the filter plates to adsorb
phosphorous.
[0069] Iron oxides and hydroxides promote the chemical
precipitation of heavy metals as insoluble metal hydroxides and
phosphates as iron-phosphates. Also, they enhance the ability of
the filter 14 or filtration system 10 to adsorb pollutants. Other
additives may include limestone expanded clay and recycled
concrete.
[0070] Certain zeolites having an infinity to heavy metal ions can
also be blended in with the crushed rock or stone and cement in
mixture so the zeolite can be embedded directly in the filter
element 102. Alternatively, a layer of zeolite can be inserted in a
space between adjacent plates of porous concrete filter element
102. Suitable zeolites may include clinoptilolite, phillipsite, or
mordenite.
[0071] It is contemplated a slow release bactericidal agent can be
added to the concrete blend or added as an intermediate layer
between filter plates to kill various target bacteria, such as E.
Coli resulting from fecal pollution.
[0072] In operation storm water runoff from roads, parking lots,
building roofs, etc., flows into shaft 100 where leaves, sticks,
and other debris greater than the mesh size of sieve 600 are caught
for subsequent removal. Storm water carrying particles of dirt and
sand along with other dissolved pollutants flow through pipe 700
and through water inlet 120 into lower compartment 900 to create a
circulating flow promoting the settling out of non-floatable debris
into sump 150. As the storm water builds up in lower chamber 900,
it ultimately permeates through the porous concrete filter element
102 to reach the level of outlet pipe 180, In passing through
filter element 102, various pollutants are either trapped within
the filter element 102 or are precipitated out therefrom to end up
in the sump or sludge trap 150.
[0073] Be cause filter element 102 is constantly located under the
static liquid level maintained in the vessel, it prevents drainage
and resulting clogging of filter element 102 by fine sediments.
Also, the circulatory flow of water beneath filter element 102
provides a scrubbing action tending to remove solid particles and
oils from the undersurface of the filter element 102. The lifetime
of the porous concrete filter material necessarily depends on the
concentration of pollutants in the runoff water reaching shaft 200.
On average, the filter element 102 need only be replaced about
every two years. However, in many installations, much less frequent
replacement is required.
[0074] With reference to FIG. 12, a flow process diagram of a
method of constructing a filtration system 10 in an embodiment of
the present invention is shown. In filtration system 10
construction process 310 sediment storage area 22 could be formed
near the bottom of housing 12 at state 312. Separator 16 could then
be positioned above sediment storage area 22 at state 314. Porous
filter 14 can then be placed above separator 16 with inlet pipe 18
entering between filter 14 and separator 16 at state 316. Finally,
cap 12D with access hatch 24 could be coupled above filter 14
having outlet 20 located inbetween at state 318.
[0075] Thus, embodiments of the LIQUID FILTRATION SYSTEM are
disclosed. One skilled in the art will appreciate the present
teachings can be practiced with embodiments other than those
disclosed. The disclosed embodiments are presented for purposes of
illustration and not limitation, and the present teachings are
limited only by the claims follow.
* * * * *