U.S. patent application number 14/674778 was filed with the patent office on 2015-08-13 for apparatus and method for increasing hydraulic capacity of a gravity sewer.
The applicant listed for this patent is The White Oak Partnership, LP. Invention is credited to Alan F. HASSETT.
Application Number | 20150225938 14/674778 |
Document ID | / |
Family ID | 53774467 |
Filed Date | 2015-08-13 |
United States Patent
Application |
20150225938 |
Kind Code |
A1 |
HASSETT; Alan F. |
August 13, 2015 |
APPARATUS AND METHOD FOR INCREASING HYDRAULIC CAPACITY OF A GRAVITY
SEWER
Abstract
A method for increasing hydraulic capacity of a gravity sewer
system includes installing a receiving structure within or
proximate to at least a portion of the gravity sewer system. The
receiving structure has at least one fluid inlet opening, at least
one liquid outlet opening, and at least one gas outlet opening. The
method further includes evacuating at least some of any gas within
the receiving structure through the at least one gas outlet opening
to create a vacuum within the receiving structure, receiving a flow
of at least liquid through the at least one fluid inlet opening of
the receiving structure and into the receiving structure, and
discharging at least some of the liquid from the receiving
structure through the at least one liquid outlet opening of the
receiving structure.
Inventors: |
HASSETT; Alan F.; (Newtown
Square, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The White Oak Partnership, LP |
Newtown Square |
PA |
US |
|
|
Family ID: |
53774467 |
Appl. No.: |
14/674778 |
Filed: |
March 31, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13967672 |
Aug 15, 2013 |
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14674778 |
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PCT/US12/25561 |
Feb 17, 2012 |
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13967672 |
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61995097 |
Apr 2, 2014 |
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61463456 |
Feb 17, 2011 |
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Current U.S.
Class: |
137/14 ;
137/203 |
Current CPC
Class: |
E03F 5/101 20130101;
Y10T 137/3102 20150401; E03F 5/08 20130101; Y10T 137/0396 20150401;
Y10T 137/0318 20150401; Y02A 10/30 20180101; Y10T 137/402 20150401;
E03F 1/007 20130101; Y02A 10/36 20180101 |
International
Class: |
E03F 5/08 20060101
E03F005/08; E03F 1/00 20060101 E03F001/00 |
Claims
1. A method for increasing hydraulic capacity of a gravity sewer
system, the method comprising: installing a receiving structure
within or proximate to at least a portion of the gravity sewer
system, the receiving structure having at least one fluid inlet
opening, at least one liquid outlet opening, and at least one gas
outlet opening; evacuating at least some of any gas within the
receiving structure through the at least one gas outlet opening to
create a vacuum within the receiving structure; receiving a flow of
at least liquid through the at least one fluid inlet opening of the
receiving structure and into the receiving structure; and
discharging at least some of the liquid from the receiving
structure through the at least one liquid outlet opening of the
receiving structure.
2. An apparatus for increasing hydraulic capacity of a gravity
sewer system, the apparatus comprising: a receiving structure
operatively connected to the gravity sewer system, the receiving
structure including: at least one fluid inlet opening operatively
connected to an upstream section of the gravity sewer system; at
least one liquid outlet opening operatively connected to a
downstream section of the gravity sewer system; and at least one
gas outlet opening; at least one vacuum device operatively
connected to the at least one gas outlet opening of the receiving
structure; and with no liquid evacuation device operatively
connected to the at least one liquid outlet opening.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of
U.S. patent application Ser. No. 13/967,672, filed on Aug. 15,
2013, currently pending, which is a continuation application of
International Application No. PCT/US2012/025561, filed Feb. 17,
2012, which was published on Aug. 23, 2012, under International
Publication No. WO 2012/112838 A1, and which claims the benefit of
U.S. Provisional Patent Application No. 61/463,456, filed Feb. 17,
2011 and entitled "A System and Method For Increasing Hydraulic
Capacity of an Existing Sewer for Use With Combined Sewer Systems
and Sanitary Sewer Systems," the entire contents of all of which
are incorporated by reference herein.
[0002] This application also claims priority to U.S. Provisional
Patent Application No. 61/995,097, filed on Apr. 1, 2014, entitled
"Apparatus and Method for Increasing Hydraulic Capacity of a
Gravity Sewer," currently pending, the entire contents of which are
incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0003] The present invention is directed generally to an apparatus
and method for increasing the hydraulic capacity of a sewer system.
More particularly, the present invention is directed to a receiving
structure positioned within or proximate to a gravity sewer system
for increasing the hydraulic capacity of the sewer system during a
period in which the gravity-flow capacity of the sewer system would
otherwise be exceeded.
[0004] Combined sewer systems were the "state-of-the-art" during
the early 20th century. In addition to the collection and transport
of municipal wastewater, these combined sewers were designed for
stormwater flows as well--therefore the term "combined." The design
of combined sewer systems included "overflow structures." When a
wet weather event (for example, a storm, heavy rain or snowmelt)
created stormwater flows which exceeded the design capacity (i.e.,
hydraulic capacity) of the combined sewer system, the excess flow
(i.e., the combined sewer overflow "CSO") would be intentionally
diverted to nearby surface water via these overflow structures.
[0005] Later in the 20th century, the "state-of-the-art" shifted to
the design and construction of separate sewers--individual sewer
systems for municipal wastewater and stormwater. The design
capacity of the sanitary sewer was intended to collect and
transport municipal wastewater from the service area. Experience
has shown that unintended water from non-municipal sources (i.e.,
stormwater) also enters the sanitary sewers. During wet weather
events these excessive flows create sanitary sewer overflows
("SSO") at locations which were not intentionally designed to
accommodate such overflows.
[0006] The current approach taken by the United States
Environmental Protection Agency ("USEPA") to deal with the issue of
CSO and SSO environmental impacts is based on legally-binding
"Consent Decree" agreements between the USEPA and the sewer system
entity--typically a municipal government or agency. The
individually-negotiated Consent Decrees include a scope-of-work and
schedule intended to reduce the frequency and volume of CSO during
wet weather events.
[0007] The scope-of-work includes an assessment and evaluation of
technically-feasible alternatives. Where increased hydraulic
capacity is needed in order to reduce the frequency and volume of
overflows, the typical alternatives often considered are parallel
sewers and/or tunnels. Such alternatives are often very expensive
solutions to deal with short-duration problems created by only a
few wet weather events annually.
[0008] Therefore, it would be desirable to create an apparatus and
method that alleviates or overcomes the above-described
disadvantages of conventional sewer systems. More specifically, it
would be desirable to create an attachment or addition to gravity
sewer systems that--when necessary or desired--increases the
hydraulic capacity of the sewer system, which is preferably an
established or existing gravity sewer system. The present invention
accomplishes the above objectives.
BRIEF SUMMARY OF THE INVENTION
[0009] Briefly stated, a preferred embodiment of the present
invention provides a system and method for increasing the hydraulic
capacity of a gravity sewer. A "receiving structure" of the present
invention is constructed at a downstream end of a section of sewer
which is in need of additional capacity. When the receiving
structure is caused to have an internal pressure less than
atmospheric pressure, the hydraulic gradient of the section of
sewer is increased; and, thereby its hydraulic capacity can be
increased and controlled.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] The following detailed description of preferred embodiments
of the invention will be better understood when read in conjunction
with the appended drawings. For the purpose of illustration, there
are shown in the drawings embodiments which are presently
preferred. It should be understood, however, that the invention is
not limited to the precise arrangements and instrumentalities
shown.
[0011] In the drawings:
[0012] FIG. 1 is a schematic view, partially in cross-section, of
two sections of a gravity sewer with sewer pipe or conduit between
adjacent manholes. The first sewer pipe 12 is relatively flat; and,
the second sewer pipe 16 is relatively steep. At full-flow, the
hydraulic gradients (14a and 14b) are parallel to the slope of each
sewer pipe. While normally depicted above the sewer pipe, in this
figure the hydraulic gradient is intentionally shown beneath the
sewer pipe in order to more clearly demonstrate the effect of the
present invention.
[0013] FIG. 2 is a schematic view, partially in cross-section, of
the first and second sewer pipes of FIG. 1 plus a receiving
structure (10). Also, at least one vacuum device 26 is connected to
gas outlet opening 22 of receiving structure 10. While normally
depicted above the sewer pipes, in this figure the overall
hydraulic gradient 14c is intentionally shown beneath the sewer
pipes in order to more clearly demonstrate the effect of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Certain terminology is used in the following description for
convenience only and is not limiting. The words "left," "top," "up"
and down," and derivatives thereof, designate directions in the
drawings to which reference is made. Unless specifically set forth
herein, the terms "a," "an" and "the" are not limited to one
element, but instead should be read as meaning "at least one." The
terminology includes the words noted above, derivatives thereof and
words of similar import.
[0015] Referring to the drawings, the first sewer pipe 12 of FIG. 1
has a maximum hydraulic capacity at full flow of a liquid, such as
water, which is determined by its size and material-of-construction
and its hydraulic gradient 14a. Likewise, the second sewer pipe 16
of FIG. 1 has a maximum hydraulic capacity at full flow of a
liquid, such as water, which is determined by its size and
material-of-construction and its hydraulic gradient 14b. It is
preferred that the second sewer pipe 16 will have a full-flow
hydraulic capacity which is greater than the first sewer pipe
12.
[0016] Flows in excess of the maximum hydraulic capacity of first
sewer pipe 12 will back-up and cause overflow conditions upstream
(i.e., to the left in FIG. 1) of first sewer pipe 12.
[0017] Referring to the drawings, FIG. 2 shows a downstream end of
first sewer pipe 12 of FIG. 1 connected to a receiving structure 10
as is the upstream end of second sewer pipe 16 of FIG. 1. Except
for these connections and outlet opening 22 to vacuum device 26,
the receiving structure 10 is otherwise preferably a completely
enclosed system or container; but, the present invention is not so
limited
[0018] The air within receiving structure 10 is caused by vacuum
device 26 to have an internal vacuum [the air pressure ("Pair") is
less than atmospheric pressure]. The equipment and controls for
these vacuum wastewater systems are well known by those skilled in
the art, and further description thereof is not necessary for a
full and complete understanding of the present invention.
Atmospheric pressure at sea level is approximately 14.7 psi which
is approximately equivalent to 34 feet w.c. (water column). In
other words, for example, a column of water 34 feet high would
create a pressure of approximately 14.7 psi at the base of the
column.
[0019] While a perfect vacuum is impractical for actual operation,
if the air within receiving structure 10 was eliminated in order to
create a perfect vacuum, the hydraulic gradient 14a at the
downstream end of first sewer pipe 12 in FIG. 1 would be lowered by
approximately 34 feet.
[0020] In actual practice, the design and operation of the present
invention will be site-specific and dependent upon creating the
increased hydraulic capacity desired. In actual practice, it will
be practical to operate so that the air pressure within the
receiving structure 10 is caused to be in-the-range-of
approximately 6/7 to 3/7 of atmospheric pressure thereby lowering
the hydraulic gradient at the downstream end of first sewer pipe 12
by approximately 5-20 feet and thereby substantially increasing the
hydraulic capacity of first sewer pipe 12 when compared with its
full-flow gravity capacity.
[0021] As shown in FIG. 2, at the upstream end of second sewer pipe
16 the hydraulic gradient 14c is also lowered by the same amount as
it is the at the downstream end of first sewer pipe 12. This
decreases the hydraulic capacity of the second sewer pipe 16 (when
compared to its full-flow gravity capacity) while still having a
hydraulic capacity equal or exceeding the increased hydraulic
capacity of first sewer pipe 12. Importantly, the result is to
create an overall hydraulic gradient 14c which is greater than the
gravity-flow hydraulic gradient 14a of first sewer pipe 12 thereby
creating a reduction in the frequency of overflows upstream of
first sewer 12.
[0022] Further, in "flat-to-steep" situations such as shown on FIG.
1 and FIG. 2, the increased hydraulic capacity in first sewer pipe
12 is accomplished without a pump or other liquid evacuation device
included among the apparatus. Avoiding pumps or other liquid
evacuation devices associated with receiving structure 10 obviates
the need for dealing with (via screens or similar devices) large
objects commonly found in the stormwater component of combined
sewer flows. This also eliminates the need for additional
equipment, operation and maintenance requirements for redundancy,
back-up power, controls, etc, associated with such pumps or other
liquid evacuation devices.
[0023] Another "flat-to-steep" situation can be found in combined
sewer system projects which include tunnels. Relatively flat
consolidation sewers intercept flow at CSO locations and transport
flow to (steep) tunnel drop shafts.
[0024] It is important to note that a preferred use of the present
invention is to temporarily increase the hydraulic capacity of
first sewer pipe 12--perhaps for only a few hours during each of
only a few wet weather events per year. Furthermore, the increase
in hydraulic capacity is preferably widely adjustable (by
selectively, for example, controlling the vacuum level in the
receiving structure 10) and can be tailored to match the conditions
created by specific wet weather events when they occur. The capital
and operating cost savings possible through the use of the present
invention are thought to be very significant when compared to the
very expensive alternatives of parallel sewers and/or tunnels for
the reduction of CSO and SSO frequency and volume.
[0025] As understood by those skilled in the art, an existing first
sewer pipe 12 and/or an existing second sewer pipe 16 such as
constructed years ago, for example, could be modified, adjusted
and/or retrofitted to accommodate or attach to one or more
receiving structures 10, which could be in series or in
parallel.
[0026] Finally, it will be appreciated by those skilled in the art
that changes could be made to the embodiments described above
without departing from the broad invention concept thereof. It is
understood, therefore, that this invention is not limited to the
particular embodiments disclosed, but is intended to cover
modifications within the spirit and scope of the present
invention.
* * * * *