U.S. patent application number 13/862088 was filed with the patent office on 2013-08-29 for slurry feed system and method.
This patent application is currently assigned to SIEMENS INDUSTRY, INC.. The applicant listed for this patent is James Paul Harshman, Timothy Frank Matheis, Michael Sumner Murphy. Invention is credited to James Paul Harshman, Timothy Frank Matheis, Michael Sumner Murphy.
Application Number | 20130220431 13/862088 |
Document ID | / |
Family ID | 45465949 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130220431 |
Kind Code |
A1 |
Matheis; Timothy Frank ; et
al. |
August 29, 2013 |
SLURRY FEED SYSTEM AND METHOD
Abstract
The invention can provide or facilitate systems and methods for
feeding a slurry and, in particular, to systems and methods for
treating wastewater streams with a slurry having periodic flushing
of conduits.
Inventors: |
Matheis; Timothy Frank;
(Palmetto, FL) ; Harshman; James Paul;
(Brandenton, FL) ; Murphy; Michael Sumner;
(Sarasota, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Matheis; Timothy Frank
Harshman; James Paul
Murphy; Michael Sumner |
Palmetto
Brandenton
Sarasota |
FL
FL
FL |
US
US
US |
|
|
Assignee: |
SIEMENS INDUSTRY, INC.
Alpharetta
GA
|
Family ID: |
45465949 |
Appl. No.: |
13/862088 |
Filed: |
April 12, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12835322 |
Jul 13, 2010 |
8430112 |
|
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13862088 |
|
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Current U.S.
Class: |
137/2 ; 137/1;
137/15.05; 137/561R |
Current CPC
Class: |
Y10T 137/0424 20150401;
Y10T 137/8593 20150401; Y10T 137/4259 20150401; C02F 2209/06
20130101; C02F 2209/40 20130101; C02F 1/66 20130101; Y10T 137/877
20150401; C02F 2209/03 20130101; C02F 2101/101 20130101; Y10T
137/0324 20150401; Y10T 137/4252 20150401; C02F 1/008 20130101;
Y10T 137/0318 20150401; C02F 1/685 20130101; B08B 9/0325 20130101;
B08B 9/032 20130101; C02F 2209/02 20130101; Y10T 137/85978
20150401; C02F 2209/09 20130101; Y10T 137/85986 20150401; C02F
2303/02 20130101 |
Class at
Publication: |
137/2 ;
137/15.05; 137/561.R; 137/1 |
International
Class: |
B08B 9/032 20060101
B08B009/032 |
Claims
1. A method of controlling odor in a wastewater stream comprising:
introducing a treating slurry for a predetermined treating period
through a conduit to the wastewater stream; introducing a flushing
fluid to the conduit for a predetermined forward flushing period;
and introducing the flushing fluid to the conduit for a
predetermined reverse flushing period.
2. The method of claim 1, wherein the predetermined forward
flushing period is in a range of from about 60 seconds to about 180
seconds and the predetermined reverse flushing period is in a range
of from about 20 seconds to about 120 seconds.
3. The method of claim 1, wherein the predetermined treating period
is in a range of from about 30 minutes to about 120 minutes.
4. The method of claim 1, further comprising measuring one or more
parameters of at least one of the wastewater stream, the treating
slurry, and the source of the treating slurry.
5. The method of claim 4, wherein the measured parameter is
selected from the group consisting of flowrate, pH, pressure,
temperature, volume of the treating slurry, pump speed, and
viscosity.
6. The method of claim 5, further comprising adjusting a flowrate
of the treating slurry based at least in part on the measured
parameter.
7. The method of claim 1, further comprising: measuring a
wastewater stream parameter and a treating slurry parameter;
identifying a control profile based at least in part on the
wastewater stream parameter and the treating slurry parameter; and
regulating addition of the treating slurry into the wastewater
stream based at least in part on the control profile.
8. The method of claim 1, further comprising generating an alarm
condition when a magnitude of a difference between at least one
expected value and at least one measured parameter of the system
exceeds a predetermined tolerance value.
9. A computer readable medium including computer readable signals
stored thereon defining instructions that, as a result of being
executed by a controller, instruct the controller to perform a
method of wastewater odor control comprising: generating at least
one first control signal in a treating mode; generating at least
one second control signal in a flushing mode; identifying a first
triggering condition that initiates generation of the second
control signal; and identifying a second triggering condition that
re-initiates generation of the first control signal.
10. The computer readable medium of claim 9, wherein identifying
the first triggering condition comprises: monitoring a duration of
an elapsed treating time during which the first control signal is
generated; and comparing the duration of the elapsed treating time
to a target treating period.
11. The computer readable medium of claim 10, wherein identifying
the second triggering condition comprises: monitoring a duration of
an elapsed flushing time during which the second control signal is
generated; and comparing the duration of the elapsed flushing time
to a target flushing period.
12. The computer readable medium of claim 9, wherein identifying
the first triggering condition comprises: measuring a flowrate of a
treating slurry introduced into the wastewater; and comparing the
measured flowrate to an expected flowrate of the treating slurry to
be introduced into the wastewater.
13. A method of facilitating odor control of a wastewater stream
comprising: providing a controller configured to actuate a pump
that is disposed to deliver a treating slurry to the wastewater
stream through a conduit.
14. The method of claim 13, further comprising storing a
predetermined treating period in the controller.
15. The method of claim 13, wherein the treating slurry comprises
at least one of calcium hydroxide and magnesium hydroxide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of pending U.S.
patent application Ser. No. 12/835,322, filed Jul. 13, 2010, titled
"SLURRY FEED SYSTEM AND METHOD," which is herein incorporated by
reference in its entirety for all purposes.
BACKGROUND OF INVENTION
Field of Invention
[0002] This invention relates to systems and methods for feeding a
slurry and, in particular, to systems and methods for treating
wastewater streams with a slurry having periodic flushing of
conduits.
SUMMARY OF THE INVENTION
[0003] One or more aspects of the invention can be directed to a
method of controlling odor in a wastewater stream comprising
introducing a treating slurry for a predetermined treating period
through a conduit to the wastewater stream. The method can comprise
introducing a flushing fluid to the conduit for a predetermined
forward flushing period, and introducing the flushing fluid to the
conduit for a predetermined reverse flushing period. In certain
embodiments, the predetermined forward flushing period is in a
range of from about 60 seconds to about 180 seconds and the
predetermined reverse flushing period is in a range of from about
20 seconds to about 120 seconds. Additionally, the predetermined
treating period can be in the range of from about 30 minutes to
about 120 minutes. The method can further comprise measuring one or
more parameters of at least one of the wastewater stream, the
treating slurry, and the source of the treating slurry. The
measured parameter can be any one or more selected from the group
consisting of flowrate, pH, pressure, temperature, volume of the
treating slurry, pump speed, and viscosity. The method can further
comprise adjusting a flowrate of the treating slurry based at least
in part on the measured parameter. Even further, the method can
comprise measuring a wastewater stream parameter and a treating
slurry parameter, identifying a control profile based at least in
part on the wastewater stream parameter and the treating slurry
parameter and regulating addition of the treating slurry into the
wastewater stream based at least in part on the control profile. In
still further embodiments, the method can comprise generating an
alarm condition when a magnitude of a difference between at least
one expected value and at least one measured parameter of the
system exceeds a predetermined tolerance value.
[0004] In accordance with one or more embodiments, the invention
can provide a system for treating wastewater comprising a source of
a treating slurry and a pump disposed to deliver at least a portion
of the treating slurry to the wastewater. The system further
comprises a source of a flushing fluid, and a controller configured
to energize the pump in a treating mode that delivers the at least
a portion of the treating slurry to the wastewater, and further
configured to energize the pump in a first flushing mode that
introduces the flushing fluid to a conduit that connects the source
of the treating slurry to the wastewater, and to energize the pump
in a second flushing mode that introduces the flushing fluid to the
conduit. The controller can be further configured to actuate a
first valve, located downstream from the source of the treating
slurry and upstream of the pump, in an open position; a second
valve, located downstream of the pump, in an open position; and a
third valve, located downstream from the source of the flushing
fluid, in a closed position, when in the treating mode. The
controller of the system can be configured to actuate the first
valve and the third valve in an open position, and to actuate the
second valve in a closed position, when in the first flushing mode.
The controller of the system can also be configured to actuate the
first valve in a closed position, and to actuate the second valve
and the third valve in an open position, when in the second
flushing mode. The controller can be further configured to adjust a
flowrate of at least one of the treating slurry from the source of
the treating slurry and the flushing fluid from the source of the
flushing fluid. The source of the treating slurry can comprise a
mixer disposed to agitate the treating slurry. The treating slurry
can comprise an alkaline earth hydroxide. The flushing fluid can be
selected from the group consisting of water and an acidic solution.
The viscosity of the treating slurry can be less than about 1000
centipoise.
[0005] In accordance with one or more embodiments, the invention
can provide a computer readable medium including computer readable
signals stored thereon defining instructions that, as a result of
being executed by a controller, instruct the controller to perform
a method of wastewater odor control comprising generating at least
one first control signal in a treating mode, generating at least
one second control signal in a flushing mode, identifying a first
triggering condition that initiates generation of the at least one
second control signal, and identifying a second triggering
condition that re-initiates generation of the at least one first
control signal. Identifying the first triggering condition can
comprise monitoring a duration of an elapsed treating time during
which the first control signal is generated, and comparing the
duration of the elapsed treating time to a target treating period.
Identifying the second triggering condition comprises monitoring a
duration of an elapsed flushing time during which the second
control signal is generated, and comparing the duration of the
elapsed flushing time to a target flushing period. Identifying the
first triggering condition comprises measuring a flowrate of a
treating slurry introduced into the wastewater, and comparing the
measured flowrate to an expected flowrate of the treating slurry to
be introduced into the wastewater. Non-limiting examples of the
computer readable medium can include compact discs, flash memory
devices, hard discs, and floppy discs.
[0006] In accordance with one or more embodiments, a method of
facilitating odor control of a wastewater stream is provided that
comprises providing a controller configured to actuate a pump that
is disposed to deliver a treating slurry to the wastewater stream
through a conduit. The method can further comprise storing a
predetermined treating period in the controller. The treating
slurry can comprise at least one of calcium hydroxide and magnesium
hydroxide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings are not intended to be drawn to
scale. In the drawings, each identical or nearly identical
component that is illustrated in the various figures is represented
by a like numeral. For purposes of clarity, not every component may
be labeled in every drawing.
[0008] In the drawings:
[0009] FIG. 1 is a schematic illustration of a system in accordance
with one or more aspects of the invention; and
[0010] FIG. 2 is a flow chart illustrating a process for flushing a
system in accordance with one or more embodiments of the
invention.
DETAILED DESCRIPTION
[0011] The invention is not limited in its application to the
details of construction and arrangement of components, systems or
subsystems set forth in the description, including the various
examples or as illustrated in the drawings. The invention is
capable of other embodiments and of being practiced or of being
carried out in various ways. The terms used herein for the purpose
of description should not be regarded as limiting. The use of the
terms "comprising," "including," "carrying," "having,"
"containing," "involving," and the like are to be understood to be
open-ended, i.e., to mean including but not limited to. Only the
transitional phrases "consisting of" and "consisting essentially
of" shall be closed or semi-closed transitional phrases,
respectively, as set forth, with respect to the claims.
[0012] Use of ordinal terms such as "first," "second," "third," and
the like in the specification and claims to modify an element does
not by itself connote any priority, precedence, or order of one
element over another or the temporal order in which acts of a
method are performed, but are used merely as labels to distinguish
one element having a certain name from another element having a
same name, but for use of the ordinal term, to distinguish the
elements.
[0013] One or more aspects of the invention can provide or
facilitate wastewater treatment systems. One or more aspects of the
invention can advantageously provide or facilitate reducing costs
typically associated with operation of a wastewater treatment
system and, in some cases, increase the operational availability
and reliability thereof. The costs may include lost time due to
shutdown periods required to unclog conduits used to deliver
treating agents or treating slurries to a fluid, such as a
wastewater stream.
[0014] A "parameter" is typically a measured or calculated
quantity. Examples of parameters include, but are not limited to,
pH, time, flowrate, viscosity, temperature, pressure, tank level,
tank volume, concentration, oxidation-reduction potential,
turbidity, mass, and volume. Process parameters can also be
intrinsic quantities such as, but not limited to, expansion
coefficient, enthalpy, boiling point, freezing point, density,
thermal conductivity, and heat capacity. Parameters may involve an
indication or condition of a component of the treatment system of
the invention. For example, any of energize, open, de-energize,
close, or stand-by may be measured parameters in accordance with
some configurations of the invention.
[0015] A "triggering condition" or "trigger" refers to one or more
requirements, prerequisites, or restrictions that must be satisfied
before a change can be initiated or accepted. For example, a
threshold parameter can invoke a triggering condition by requiring
a parameter, which can be a measured, inferred, and/or calculated
quantity, to meet or exceed a predetermined value. The latter can
be a predetermined or preset constant but can also vary with
respect to the triggering condition or vary depending on a control
algorithm.
[0016] The terms "sewer" and "sewage collection system" refer to a
conduit, or a series and/or a network of conduits that may be
interconnected through one or more pumps or lift-stations. The
terms "treatment system" and "treatment facility" refer to any
system in which fluid, typically wastewater and/or sewage, is
treated, processed, or otherwise rendered to have at least one
undesirable constituent modified, removed, or a concentration
thereof, reduced therefrom.
[0017] In accordance with one or more embodiments, the systems and
techniques of the invention can be characterized as optimizing the
control of odor associated with a fluid, for example a fluid
associated with or containing waste products or wastewater derived
from coke ovens, asphalt, oil and gas, tanneries, food processing,
sewage, wastewater, paper mills, and other manufacturing
facilities. The systems and techniques of the invention can also be
characterized as providing a control system or controller or
utilizing a control system that allows for efficient and
cost-effective flushing of a wastewater treatment system or system
for controlling odor in a fluid or a wastewater stream to remove,
reduce, or minimize clogging associated with a treating agent or
treating slurry.
[0018] The systems and techniques of the invention can be further
characterized as providing one or more controllers or techniques
that can regulate the operation of one or more water treatment
systems including, but not limited to, water and/or wastewater
treatment systems that typically involve adding, to the fluid to be
treated, one or more treating agents, or treating slurries. The
systems and techniques of the invention can control or at least
effect control of addition of one or more of the treating agents or
treating slurries.
[0019] As exemplarily shown in FIG. 1, one or more embodiments of
the invention can be directed to a treatment system 100 containing
fluid to be treated, such as wastewater 112. System 100 typically
further includes a source of treating slurry and a source of
flushing fluid 116. The source of the treating slurry can be a tank
114 as depicted in FIG. 1 comprising a mixer 115 suitable for
maintaining the solids in suspension within the treating slurry. A
pump 118 is disposed to introduce treating slurry to wastewater 112
by pumping treating slurry from the source of treating slurry
through conduit 120, valve 122, conduit 124, conduit 126, conduit
128, conduit 130, valve 132, and conduit 134 to wastewater 112. The
pump 118 may also be used to introduce a flushing fluid into any
one or more of the conduits by pumping flushing fluid from the
source of flushing fluid 116 through conduit 136, valve 138,
conduit 140, and either conduits 142 and 143 or conduits 144 and
145 to flush at least part of the conduit comprising conduit 120,
124, 126, 128, 130, and 134. Typically, the treating slurry and
flushing fluid is pumped through the system for predetermined
periods of time. In certain embodiments, it may be desirable to
place the juncture of conduit 143 and conduits 124 and 126 as close
to tank 114 as possible. Likewise, it may be desirable to place the
juncture of conduit 145 and conduits 128 and 132 as close to the
wastewater 112 as possible.
[0020] Other configurations of the invention may not involve pump
118 to introduce flushing fluid from the source of flushing fluid
116. For example, if the source of flushing fluid is pressurized or
at least has a pressure greater than the pressure losses associated
with flowing the fluid through any of the conduits and valves, then
the pump may be bypassed.
[0021] Pumps used in the system and techniques of the invention can
be any pump suitable for delivering one or more treating agents or
treating slurries to a fluid, such as a wastewater stream. For
example, pump 118 can be a positive displacement pump such as a
peristaltic pump, a diaphragm pump, or a progressing cavity pump.
In certain embodiments, the pump may be a variable speed pump to
accommodate fluctuations in demand associated with treating the
fluid. The valves used in the system and techniques of the
invention may be any device that regulates the flow of fluid by
opening, closing or partially obstructing a passageway or conduit.
A valve in an open position or partially open position allows fluid
to flow in a direction of higher pressure to lower pressure. A
valve in a closed position prevents fluid from flowing
therethrough. The valves used in the present system in techniques
may include, for example, ball valves, butterfly valves, check
valves, ceramic disc valves, and piston valves.
[0022] A treating slurry can be used in the present invention for
treating a fluid such as a wastewater stream or any fluid in which
it is desired to have at least one undesirable constituent removed,
or a concentration thereof, reduced therefrom. The slurry may
comprise any mixture of solids suspended in a liquid, in which the
solids, and/or liquid are suitable for treating a fluid. The solids
and/or liquid may be suitable, for example, for removing at least
one undesirable component, or reducing a concentration of at least
one undesirable component from a fluid to be treated. The solids
may comprise particular treating agents, for example, alkaline
earth hydroxides such as calcium hydroxide, magnesium hydroxide,
and mixtures thereof. Other suitable treating agents may be used
such as nitrate containing species or other alkaline materials.
Particularly advantageous agents of the invention can affect at
least one characteristic of the fluid. Non-limiting examples of
treating agents include acids, bases, oxidizers, disinfectants, as
well as those commercially available as BIOXIDE.RTM. solution,
BIOXIDE.RTM. AE slurry, BIOXIDE-AQ.RTM. slurry, Alk AQUIT.TM. 25
slurry, and ODOPHOS.RTM. ferrous iron solution, each of which is
available from Siemens Water Technologies Corp., Warrendale,
Pa.
[0023] The liquid of the treating slurry utilized is typically
water, but can be any other suitable liquid for mixing the solids
component of the slurry, allowing the solids component to remain in
suspension to form a suitable slurry for introducing into a fluid
to be treated. The liquid may comprise components dissolved or
blended therein, such as additional treating agents such as
anthraquinone.
[0024] The slurry may comprise any mixture of solids suspended in a
liquid that may allow the slurry to flow through a conduit to be
introduced to a fluid to be treated. In certain embodiments, the
treating slurry can have a weight % of less than about 35%, about
30%, about 25%, about 20%, or about 15%, depending on the
particular solids and liquids utilized. The slurry may be referred
to as a milk, or a thin slurry having a weight percent of solids
that allows the slurry to readily flow. A milk of lime slurry may
refer to a treating slurry comprising calcium hydroxide or
magnesium hydroxide, or mixtures thereof, having a weight % of less
than about 15 weight % to about 30 weight %, more particularly,
about 20 weight % to about 25 weight %. In certain embodiments, the
treating slurry may have a viscosity less than about 1000
centipoises.
[0025] The flushing fluid utilized in the systems and techniques of
the invention can be any fluid suitable for introducing to a system
to cleanse, unclog, unfoul, rinse, wash, disinfect, scour, purge,
sterilize, dissolve or otherwise remove any solids accumulated in
any portion of the system including conduits, pumps and valves
between a source of a treating slurry and a fluid to be treated.
The fluid can be water or an acidic solution, such as a solution of
hydrochloric acid. The flushing fluid may be a dilute acid
solution, for example, a 1 to 10 dilution, a 1 to 100 dilution, or
a 1 to 1000 dilution of acid in water. In certain embodiments, the
flushing fluid utilized can be a solution of 1 part hydrochloric
acid solution to 100 parts water.
[0026] In certain embodiments, the flushing fluid can be compatible
with the fluid and solids of the treating slurry and/or the fluid
to be treated such that no chemical reactions occur between the
flushing fluid and the liquid and solid components of the treating
slurry, or between the flushing fluid and the components of the
fluid to be treated.
[0027] In operation of the treatment system 100, in a first mode,
or treating mode, treating slurry from tank 114 is delivered to
wastewater 112 using pump 118 through conduits 120, 124, 126, 128,
130, and 134. Valves 122 and 132 are in the open position, and
valve 138 is in the closed position. In a second mode, or a
flushing mode, flushing fluid from the source of flushing fluid 116
is delivered through valve 138 in an open position. In a forward
flushing mode, valve 132 remains in an open position, and valve 122
is in a closed position. Flushing fluid from the source of flushing
fluid 116 is delivered to wastewater 112 using pump 118 in the
forward direction, allowing the flushing fluid to be delivered
through conduits 136, 140, 142, 143, 126, 128, 130, and 134.
Flushing fluid may also enter conduits 124 and 145. Operating the
system 100 in this flushing mode allows removal of any materials
that may be inhibiting or reducing flow of treating slurry in a
portion of the system that delivers treating slurry to the
wastewater 112 through at least conduits 126, 128, 130, and 134 and
valve 132 to the wastewater. Check valves 146 and 148 prevent the
flow of treating slurry into conduits 142 and 144,
respectively.
[0028] In an additional or alternative second mode, or flushing
mode, flushing fluid from the source of flushing fluid 116 can be
delivered to wastewater 112 using pump 118 in the reverse
direction. In this reverse flushing mode, flushing fluid from the
source of flushing fluid 116 is delivered through valve 138 in an
open position. Valve 132 is in a closed position, and valve 122 is
in an open position. Flushing fluid from the source of flushing
fluid 116 is delivered to the source of treating slurry 114 using
pump 118 in the reverse direction, allowing the flushing fluid to
be delivered through conduits 136, 140, 144, 145, 128, 126, 124,
and 120. Flushing fluid may also enter conduits 143 and 130.
Operating the system 100 in this flushing mode allows removal of
any materials that may be inhibiting or reducing flow of treating
slurry in a portion of the system that delivers treating slurry to
the wastewater 112 through at least conduits 120, 124, 126, and 128
and valve 122 to the source of the treating slurry. As noted above,
check valves 146 and 148 prevent the flow of treating slurry into
conduits 142 and 144, respectively.
[0029] The treating slurry may be delivered to the water to be
treated for various predetermined treating periods, based on the
needs of the particular system. In some embodiments, the treating
period may be one day, while in other circumstances, the treating
period may be in the range of about 15 minutes to about 180
minutes, and more typically, the treating period may be in the
range of about 30 minutes to about 120 minutes. The flushing fluid
may also be introduced to the system for various predetermined
flushing periods. The predetermined forward flushing period and
reverse flushing period may be the same period of time or different
periods of time. For example, the forward flushing time period may
be in the range of about 30 seconds to about 180 seconds, while the
reverse flushing time may be in the range of about 10 seconds to
about 180 seconds. More typically, the predetermined forward
flushing time is in the range of about 60 seconds to about 180
seconds, and the reverse flushing time is in the range of about 20
seconds to about 120 seconds.
[0030] A secondary containment skid 154 is provided to contain any
leaks that may be associated with pump 118, and any one or more of
valves 122, 132, and 138, and any one or more conduits 120, 124,
126, 128, 130, 134, 136, 140, 142, 143, 144, and 145. A sensor 156
located in secondary containment skid 154 is in communication with
controller 150, and may allow for detection of any leaks that may
occur within the system. The leak may be detected based on a sensor
monitoring the level of liquid within the secondary containment
skid, which may trigger an alarm by sound, light, telephone,
internet, or other electronic communication to notify an operator
of a potential leak within the system.
[0031] The conduits referred to herein to introduce treating slurry
into the wastewater stream can be of any suitable diameter to
transfer the treating slurry through the system and into the
wastewater stream. In certain embodiments of the invention, the
conduits may be nominally 1/2 inch in diameter or less. The
suitable diameter may be based, in part, on the flowrate of the
treating slurry through the system, in that a higher velocity will
allow for a smaller diameter conduit. In conventional treatment
systems, it would not have been expected that a 1/2 inch diameter
conduit or hose could successfully transfer the treating slurry
into a wastewater stream as presently described herein due to
clogging that typically occurs when using a slurry having the
solids weight percent as used in the systems and techniques of the
present invention. However, based at least in part on the systems
and techniques of the present invention, a 1/2 inch diameter
conduit is suitable for successful delivery of treating slurry to a
fluid to be treated.
[0032] In certain embodiments, the controller 150 can facilitate or
regulate the delivery of treating slurry to the wastewater, or the
delivery of flushing fluid to the conduits. For example, a
controller may be configured to adjust the flowrate of the treating
slurry or the flushing fluid, actuate the valves, for example, in
an open position or a closed position, and to energize the pump,
for example, by adjust the pump speed, and starting or stopping the
pump. The controller can energize the pump in a treating mode to
deliver at least a portion of the treating slurry to a wastewater.
The controller may also be further configured to energize the pump
in a first flushing mode that introduces the flushing fluid to a
conduit that connects the source of the treating slurry to the
wastewater, and to energize the pump in a second flushing mode that
introduces the flushing fluid to the conduit.
[0033] The controller 150 may respond to signals from one or more
timers (not shown) and/or one or more sensors, exemplarily shown in
FIG. 1 as sensors 152 and 156 positioned at any particular location
within the fluid delivery system. The timers may be set to
predetermined periods of time, inputted by an operator, for periods
of time related to introducing the treating slurry to the fluid to
be treated, and/or for periods of time related to flushing of the
system, in at least one of a forward or reverse direction, which
may be stored in the controller. The predetermined periods of time
may vary based on the time of day, the week, month, or season, and
may be adjusted based on measured or calculated parameters of the
system. The predetermined periods of time may also be adjusted
based on operator input, such that if there is an immediate need to
adjust the predetermined periods of time, this may be accomplished
by an operator overriding the predetermined periods.
[0034] The treating mode and the flushing mode may also be
initiated based at least in part on a measured parameter of the
system. For example a sensor may be disposed to measure a flowrate
of the treating slurry that is introduced into the wastewater. The
sensor may be disposed in any conduit between the source of the
treating slurry and the wastewater. The controller may be
configured to compare the measured flowrate to an expected flowrate
of the treating slurry to be introduced into the wastewater, and a
change in mode may be initiated based on the comparison.
[0035] The controller can also comprise a control system that can
be used to match a treating slurry dose or flowrate to an actual
demand, e.g., odor control, of, for example, a fluid such as a
wastewater stream. The feed control system can dynamically feed a
treating slurry, e.g., a calcium hydroxide or magnesium hydroxide
slurry, based on a curve that matches continuously changing system
demands. This reduces overfeeding and underfeeding of the treating
slurry, thereby improving performance and reducing treatment
costs.
[0036] One or more embodiments of the systems and techniques of the
invention may be utilized, adapted, or otherwise incorporated into
and at least partially control, regulate, provide, maintain,
reduce, and/or eliminate one or more characteristics of a
wastewater system. In some cases, some embodiments of the invention
may be incorporated or utilized to facilitate treatment of
wastewater to change at least one characteristic thereof from
having an undesirable condition to having an acceptable condition
or quality. In particular instances, some control systems and
techniques of the invention may be utilized or incorporated in a
sewer, sewage collection system, or conveyance system of, for
example, a municipality, which typically include at least one
treatment facility wherein sewage or wastewater is treated. In
other cases, the present inventive systems and techniques may be
used in one or more subsystems of the sewage system. The invention,
however, is not limited in its application to wastewater systems
and/or components thereof. The invention may be utilized in other
municipal, commercial, and/or industrial operations that involve
monitoring, regulation, and/or management of at least one
characteristic of one or more process fluids and, in some cases, at
least one associated source of chemical or biological reactant or
agent, such as a treating slurry. Thus, although the various
aspects, features, and advantages of the invention are described
relative to a treatment facility, the invention is not limited to
such facilities and may be incorporated in such other operations.
Thus, the systems and techniques of the invention may be utilized
to regulate and at least partially change a water body or stream
from having an unfavorable condition to one having a preferred
condition. For example, the systems and techniques of the invention
may be utilized to control, regulate, and/or facilitate any of a
biological process, a chemical process, or combination thereof.
[0037] Further aspects and features of the invention advantageously
provide adaptive control approaches or methodologies to alter,
monitor, limit, restrict, manage, control, regulate, reduce, or
even minimize at least one characteristic of a treatment facility
or a component thereof. In other cases, however, the aspects and
features of the invention provide adaptive control approaches or
methodologies that increase or even maximize at least one
characteristic of a treatment facility or a component thereof. For
example, one or more aspects of the invention may be directed to
reducing or minimizing a concentration or activity of one or more
particular species, products, byproducts or properties of one or
more fluid streams in the treatment facility. Alternatively, some
aspects of the invention may be directed to increasing a
concentration of one or more particular species, products,
byproducts or properties of one or more fluid streams in the
treatment facility.
[0038] In one or more particular aspects, the invention can involve
a method of controlling addition of a treating agent into a fluid.
For example, one or more methods of the invention can comprise one
or more acts of measuring at a measurement site a process value of
a process parameter of the fluid and generating a first control
signal based on a control function and the process value. The
methods of the invention, in some cases, can further involve one or
more acts of introducing an amount of the treating slurry, based on
the first control signal into the wastewater, measuring at least
one operating parameter of a source of the wastewater, and
generating an expected operating value of the source of the
treating agent, typically based at least partially on the first
control signal. One or more methods of the invention can further
comprise one or more acts of measuring a plurality of process
values of the process parameter. In still other cases, one or more
methods of the invention can comprise one or more acts of
generating a plurality of control signals, preferably based on the
control function and the plurality of process values, and/or
generating a plurality of expected operating values of the source
of the treating agent, typically based at least partially on the
plurality of control signals as well as, or in conjunction with,
one or more acts of generating an alarm condition, typically when a
magnitude of a difference between at least one expected operating
value and at least one measured operating parameter of the source
of the treating agent exceeds a predetermined tolerance value.
[0039] Still further aspects of the invention can be directed to
feed system, such as chemical feed systems. One or more systems of
the invention can comprise at least one sensor disposed to measure
a first parameter of a wastewater stream, such as, for example, the
pH, and to transmit a first measurement signal corresponding to the
first parameter. In some cases, the system may further comprise at
least one source of a treating slurry disposed to introduce the
treating slurry into the wastewater stream. Particularly preferred
embodiments of one or more systems of the invention can comprise
one or even a plurality of controllers, wherein at least one
controller is in communication with the at least one sensor and at
least one, or the same controller is in communication with at least
one source of one or more treating agents. One or more controllers
can, in some systems of the invention, be configured to receive at
least one of the first measurement signal from the sensor and a
second measurement signal corresponding to a measured parameter of
at least one source of the treating slurry. The measured parameter
of the at least one source of the treating slurry may be, for
example, the level of the treating slurry in the tank housing the
treating slurry. Further, at least one, but typically the same,
controller can be configured to transmit to at least one source of
the treating agent at least one control signal based at least in
part on a control function and the first measurement signal.
[0040] As noted, the measured parameter can be representative of a
level of the wastewater stream. For example, the at least one input
device can comprise at least one sensor that provides at least one
measured value corresponding to a pH of the wastewater stream
downstream of the point of addition of the treating slurry.
Typically, it would be desirable to maintain the pH of the
wastewater stream to be treated in the range of about 7.5 to about
9.0.
[0041] In other examples, the measured parameter can be a
concentration of a species in the wastewater stream. The species
may include sulfides, such as hydrogen sulfide, iron sulfide,
dimethyl sulfide, and dimethyl disulfide; mercaptans; and other
odorous species or compounds located in wastewater streams.
[0042] In some embodiments of the invention the pH sensor is
disposed to measure a pH of, for example, a wastewater stream, and
transmit at least one corresponding measured pH value to at least
one controller of the system. In further pertinent embodiments of
the invention, at least one controller can then be configured to
generate at least one composite average pH curve based on at least
one of the measured pH value and, in particularly advantageous
cases, also be configured to identify a triggering condition based
at least partially on the composite average pH curve and a
currently measured pH value. One or more sensors can be remotely
disposed from a point of introduction of the treating slurry into
the wastewater stream. The triggering condition can be realized
when, for example, a difference between the composite average pH
curve and the current measured pH exceeds at least one
predetermined tolerance value. Indeed, some preferred embodiments
of the invention involve at least one controller that is
configured, or at least is configurable, to adjust the control
signal based on at least one triggering condition. Other sensors
may be disposed to measure other parameters of the system to
produce composite curves based on at least one other parameter, and
to be used advantageously in the systems and methods of the
invention.
[0043] Further embodiments of the invention utilize one or a
plurality of sensors configured to measure and preferably provide
an indication of an operating parameter or a component or subsystem
of the systems of the invention. As noted, the operating parameter
can be a state or condition and the sensor can thus provide an
indication or representation of the component or subsystem. For
example, one or more systems of the invention can comprise at least
one sensor disposed to measure a flowrate or pressure of the
treating slurry at various points throughout the system, the
current driving one or more pumps of the system, or the temperature
of the wastewater stream.
[0044] In some cases, the flowrate of the treating slurry can be
measured to further improve the control techniques of the
invention. For example, flow pacing techniques may be further
utilized to adjust the rate of treating agent introduced into the
wastewater stream. Such techniques typically determine a treating
slurry dosage rate based on, for example a typical or design
flowrate, and further decreases the dosage rate during periods of
relatively increased wastewater flow or increases in the dosage
rate during periods of relatively reduced wastewater flow.
Typically, the dosage rate can be reduced relative to a normal
control basis because the amount of time the wastewater remains in
the sewage collection system decreases, which in turn decreases the
potential or amount of sulfide produced during transit. In
contrast, simple flow pacing techniques inappropriately tends to
increase the dosage rate during high flow periods when it should be
decreasing the dose rate so as to reflect the reduced system
demand. Thus, some embodiments of the invention can comprise
utilizing a residence time of the wastewater as a basis for
controlling addition of a treating slurry. As noted, controlling
addition of the treating slurry can be based on the measured
process value, typically relative to a corresponding demand value
of a control function. The control function can further incorporate
adjusted flow pacing techniques of the invention to adjust, during,
for example, relatively high fluid flow rates, the control signal,
and effectively reduce the dosage rate of the treating slurry by
nesting the flow pacing algorithm. The systems and techniques of
the invention, however, can be practiced in other ways. For
example, the adjusted flow pacing approach of the invention can be
utilized to control a first pump configured to introduce a first
treating slurry into the wastewater stream, or a portion of one or
more treating agents into the wastewater stream at a first dosage
rate, whereas the generated control signal based on the measured
process value representing a concentration of one or more odorous
species and a demand value can be utilized to control a second pump
configured to introduce a second treating slurry or treating agent
or the first treating slurry at a second dosage rate.
[0045] The control function, or feed profile, can comprise a
plurality of demand values. In some embodiments of the invention, a
plurality of demand values can be used to constitute an array of
demand values that can at least partially define one or more
control functions. Particularly advantageous aspects of the
invention can be facilitated by utilizing at least one measured
value from at least one input device and a control function or at
lest one demand value thereof. For example, in some embodiments of
the invention, at least one process parameter is monitored to
provide a measured process value. The process value corresponding
to a demand value of a control function can then be utilized to
control and provide a corresponding control signal. For example, a
measured value at the first hour, or other time interval, of a day
can be used with a demand value assigned for the same hour, or
other time interval. If an hourly array of demand values is
predefined or predetermined, through measurements or otherwise, and
provided, then the process parameter can be measured hourly and the
corresponding measured value, along with the corresponding hourly
demand value can be used to provide a control signal. The control
signal can then be utilized to, for example, energize one or more
pumps or actuate one or more valves of one or more sources of a
treating agent. The systems and techniques of the invention can
thus control treatment based on a control function that can have a
plurality of control targets or set points.
[0046] In some embodiments of the invention, at least one of the
measured value and the operating parameter is determined
periodically, or upon demand. Thus, in some cases, a measured value
of a characteristic or condition of the wastewater stream is
measured in accordance with a predetermined schedule. For example,
the pH of the wastewater stream downstream of the point of
introduction of the treating slurry can be measured by at least one
input device at periodic intervals and thus provide a plurality of
measured values of at least one process parameter of the fluid. If,
for example, the process parameter is sampled hourly, then an array
comprising twenty-four periodic process values would be measured
daily. The array can also be configured based on a daily or weekly
demand profile. For example, a set of control points or demand
values can comprise one or more demand functions. Indeed, the
control function can be defined on a daily, weekly, monthly or
seasonal basis. In particular embodiments of the invention, a
control function is defined for each day of the week thereby being
adapted to accommodate, for example, seven sets of twenty-four
hourly demand values. The invention, however, is not limited to
embodiments involving hourly measurements and may be practiced
utilizing other sampling rates. Moreover, the sampling rates need
not be uniformly periodic and may be temporally asymmetrical in
which the sampling rate can be greater at certain periods of, for
example, an hour, day, week, or month relative to other periods of
the day, week, and/or month.
[0047] Further optimization can be realized during changes in the
diurnal flow profile commonly exhibited in municipal wastewater
systems. For example, the demand values can be dynamically adjusted
based on historically measured process values. The control
techniques of the invention can self-adjust at least one demand
value of one or more control function based on, for example, past
measured data. For example, if a measured process value is measured
or determined to be greater than an historical average, the systems
and techniques of the invention can adjust a corresponding hourly,
daily, weekly, or even monthly, demand value. The historical
average can be determined on a daily basis, e.g., as an average of
measured value of the corresponding hours of a day; on a weekly
basis, e.g., as an average of measured values of the corresponding
hours of a week; or even on a seasonal or yearly basis.
[0048] Safeguards can also be incorporated to ensure stable control
of the system. For example, the adjusted demand value can be
limited to a predetermined percentage of the original demand value,
such as, within about 10%. Other control limits may be utilized
including, but not limited to requiring operator confirmation of
any change in predefined demand values, or even requiring a
hierarchical approval relative to the magnitude of change. For
example, a relatively low percentage change, e.g., less than about
2% may be effected without approval, whereas an intermediate
percentage change, e.g., less than about 10% may be adopted with
operator-level approval, and any high percentage change, e.g.,
greater than about 10% may be incorporated with supervisory-level
permission.
[0049] In one or more embodiments of the systems and techniques of
the invention, at least one controller can be configured to
receive, for example, the second measurement signal and generate a
measured characteristic value of at least one operating parameter
of at least one source of the treating slurry. Further, at least
one controller can be further configured to generate an expected
characteristic value of at least one source of the treating slurry
based at least in part on at least one control signal, and/or to
determine a relative characteristic value based on the difference
between the measured characteristic value and the expected
characteristic value.
[0050] For example, as noted, the control systems and techniques of
the invention can generate a control signal based at least
partially on a measured value of a process parameter and a
corresponding demand value of a control function. The measured
value can be measured, for example, at a first minute and the
control signal can be based on a difference between the measured
value and the demand value as pre-designated for that first minute.
Other measurements of, for example, temperature, flowrate or other
parameters, can be performed every minute, or at other time
intervals, and would then be used along with corresponding demand
values. The plurality of periodic control signals can then be used
to generate an aggregate or total, corresponding to a treating
slurry dosage amount. The aggregate dosage amount can then be used
to estimate an expected operating parameter, condition, or value
of, for example, the source of the treating slurry. Some
embodiments of the invention further comprise one or more input
devices to monitor or measure at least one operating parameter of
the source of treating slurry. The aggregated dosage amount can
then be advantageously compared to the expected operating value or
parameter. If a difference between the measured and expected
operating conditions or values exceeds a tolerance, or a setpoint,
then one or more actions can be initiated by the systems and
techniques of the invention. For example, if the measured pH
exceeds the tolerance or setpoint, the flowrate of the treating
slurry is decreased. If the measured pH falls below the tolerance
or setpoint, the flowrate of the treating slurry is increased. For
example, if the difference exceeds a measurement error limit, then
an alarm condition can be generated and transmitted to one or more
output devices, thereby, in some cases, requiring the attention of
the operator.
[0051] Further embodiments of the invention may allow generation of
one or more control signals corresponding to a level of fluid in
the system, for example, a level of fluid in one or more subsystems
such as a tank within the system, or one or more skids such as a
containment skid for containing leaks that may occur within the
system. One or more sensors may monitor or measure the level of
fluid, and a control signal may be generated corresponding to this
measured level. The measured level can be advantageously be
compared to the expected operating conditions or parameter, and if
the difference between the measured and expected operating
conditions or parameter exceeds a tolerance, then alarm condition
can be generated and transmitted to one or more output devices to
allow for one or more actions to be carried out by an operator or
otherwise.
[0052] Further embodiments of the invention facilitate maintaining
a sufficient amount of the one or more treating slurries. In some
cases, the composite average and/or the measured operating
parameter of one or more sources of at least one treating slurry
can be utilized to initiate and/or notify when the stored amount of
treating slurry should be replenished. For example, when the
measured amount of the treating slurry in at least one source is at
or approaches a percentage of the total storage amount, the systems
and techniques of the invention can send a notification by, for
example, an alarm, and/or printed or electronic message. In some
cases, the condition for replenishing can be triggered relative to
an anticipated number of days of treating slurry remaining. This
condition can be determined based on, for example, the rate or
usage of a treating agent and the remaining volume.
[0053] In accordance with one or more embodiments of the invention,
the systems and techniques of the invention may be configured to
recognize conditions that obviates or reduces the need for treating
slurries. The systems and techniques of the invention can thus be
further configured to adjust, e.g., reduce or minimize, the control
signal during such reduced demand conditions. For example, rain can
increase the flow rate of the fluid in sewer systems. The increased
flow condition can be manifested as a direct flow meter measurement
and/or increased pump current draw. The increased flow rate,
depending on the amount of precipitation, can effectively reduce or
even eliminate the amount or dosage rate of treating slurry
because, as discussed above, of the effectively reduce fluid
residence time and/or, in some cases, because of dilution effects.
Thus, some embodiments of the systems and techniques of the
invention can be configured to recognize elevated fluid flow rates
associated with rain, which can also be referred to as rain curves.
Moreover, some embodiments of the invention contemplate adjusting
or controlling of the amount or dosage rate of the treating agent
based on the rainfall amount. For example, a flow sensor or pump
activity level can be utilized to measure a fluid flow rate; if the
measured flow rate increases in a relatively short period such as
within less than about six hours, and in contrast to a weekly or
monthly historical increase, then the treating slurry dosage amount
or rate can be reduced accordingly. Further embodiments contemplate
a staged control approach, utilizing, for example, a plurality of
rain curves to modify at least one output signal. For example,
during an abnormally high flow condition, a dosing reduction factor
can be initiated. Further rain curves can be used to define the
factors; typically, greater rainfall directs a larger adjustment
factor.
[0054] In some cases, the measured flow rate can be classified as
or according to a composite average flow rate. Further, a deviation
from the composite average flow rate, which can be defined as an
average, e.g., a moving average, of fluid flow rates, can be
utilized in adjusting the treating slurry amount or dosage rate.
For example, the treating slurry amount and/or dosage rate can be
reduced to a first level or percentage for a first predetermined
rainfall amount and to a second level or percentage for a second
predetermined rainfall amount. Further levels of adjustment can be
utilized as desired. Other embodiments may further utilize
safeguards to avoid false positive determination of rainfall
events. For example, a predetermined tolerance condition or value
may be used to validate a triggering condition indicative of the
rainfall event and/or avoid chattering nuisance. If, for example,
the amount or rate of fluid flow increases by certain predetermined
value, e.g., greater than about 10% of, for example, the composite
average flow curve, then a rainfall event is considered likely and
an adjustment of the amount and/or dosage rate would be accordingly
initiated. Other predetermined tolerance conditions or values may
also be utilized, alone or in conjunction with the above approach.
For example, the tolerance condition may require consecutive
elevated measured fluid flow rates, relative to the composite
average flow curve, before the triggering condition is recognized
or acknowledged.
[0055] Other nested or ancillary control loops may be incorporated
into or around the treating slurry dosage rate control block.
Analogous to adjusted flow pacing, the pH and/or temperature of the
fluid may be used to decrease, increase, or otherwise adjust the
control signal directed to, for example, the dosage rate of the
treating slurry. For example, where the temperature of the fluid is
elevated, especially relative to a baseline such as ambient
temperature or about 20.degree. C., the dosage rate can be
increased to counteract an increase in biological metabolic
activity. If biological activity can be considered to approximately
follow an Arrhenius temperature dependence, then the dosage rate
can be increased to accordingly compensate for a doubling of
activity or rate of generation of odorous species for every
10.degree. C. increase. Conversely, during colder periods, e.g.,
when the sewage fluid temperature approaches about 12.degree. C. to
about 13.degree. C., the control signal can be reduced to
accordingly accommodate reduced activity associated with lower
temperatures. Analogously, pH based adjustments may be utilized to
compensate odorous species generation during periods of higher and
lower fluid pH conditions. The pH and/or temperature adjusted
control blocks or algorithms can be nested with the any of the
other control blocks or algorithms.
[0056] The control signal, in some embodiments of the invention,
can actuate, activate, or otherwise facilitate energizing, and/or
de-energizing at least one unit operation of the systems and
techniques of the invention. At least one control signal, in some
embodiments, can involve time-splicing by comprising at least one
active component and at least one dormant component. In some cases,
for example, the control signal can be a composite signal
comprising a plurality of output drive signals, one or more of
which may, at any or desired period or cycle, energize or
de-energize at least one unit operation of the system. In such
cases, for example, the magnitude of the active component can,
preferably, be a function of a characteristic of at least one
component of the system of the invention and a control quantity.
For example, control signal, or an active component thereof, can,
at least partially, be based on a difference between a measured
parameter and a demand value. The control signal can, for example,
be based on the difference between the first measured parameter and
a corresponding demand value. Alternatively, or in accordance with
other embodiments of the invention, the control signal can be, at
least partially, defined as an active component of duty cycle
period. The duty cycle can comprise periods, typically alternating
active periods with dormant periods that energize and de-energize
at least one unit operation of a subsystem of the treatment system.
For example, the control signal can be comprised of a duty cycle
including at least one active period that instructs or otherwise
energizes an unit operation to, for example, perform a
predetermined procedure or task, and can further be comprised of at
least one dormant period that instructs or otherwise de-activates
the unit operation from performing the procedure.
[0057] The control signal may be manifested in terms of a duty
cycle having a predefined time period. Indeed, advantageous
embodiments of the invention can involve control signals that are
at least partially based on a duty cycle, having a plurality of
active and dormant periods. Particularly advantageous embodiments
involve control signals with duty cycles in which the temporal
magnitude of an active period is biased relative to the temporal
magnitude of a dormant period. For example, the duty cycle can be
predefined to be a one minute cycle, then an active period of the
control signal can be a fraction of one minute, e.g., six seconds
or 10% of the duty cycle; twenty seconds or about 33% of the duty
cycle; or thirty seconds or about 50% of the duty cycle. The
corresponding dormant period of the duty cycle would, respectively,
be 54 seconds or about 90% of the duty cycle; forty seconds or
about 66% of the duty cycle; or thirty seconds or about 50% of the
duty cycle. As noted, the duty cycle can be a predefined quantity
and is not limited to one minute cycles. For example, the duty
cycle can be predefined as three minutes, ten minutes, or even
sixty minutes. Defining a duty cycle can be established for each
dosing assembly or system and may even vary and be a function of
one or more factors including, for example, deviations from
expected values, such as errors in expected relative to actual
values, and even based on the time, day, month, and/or season.
[0058] The control signal may be further modified as desired by
applying one or more adjustment factors. For example, with respect
to an output signal directed to dosing one or more treating agents,
one or more dosing adjustment factors can modify the control
signal, typically, the magnitude and/or, in some cases, the
duration of the active component of the output signal. The dosing
adjustment factor can be applied to modify a rate or amount of
treating slurry introduced to the wastewater stream. For example, a
global dosing adjustment factor can be used to reduce the amount
and/or rate of a calcium hydroxide containing treating slurry by
about 5%, by about 10%, about 15%, or even by about 20%, depending,
for example, on one or a plurality of conditional requirements that
can trigger each level of adjustment. In some cases, a plurality of
dosing adjustment factors can be employed, any one or more of which
can have one or a plurality of conditions that must be present
before being activated. For example, a dosing adjustment factor can
conditionally be activated only during rainfall events, during a
predetermined part of a day, week, month, or year.
[0059] Various embodiments of the invention can further comprise
one or more acts of modifying at least one demand value of the
control function and/or generating an alternative control signal
based at least partially on the modified demand value and a second
measured process value of the process parameter. The process
parameter, in some particular embodiments of the invention, can be
representative of a concentration of an odorous species in the
wastewater stream. The measured first parameter in one or more
systems of the invention can be representative of a concentration
of a species in the wastewater stream. In one or more particular
embodiments directed to the systems of the invention, the control
function can comprise an array of demand values.
[0060] The controller may be implemented using one or more computer
systems which may be, for example, a general-purpose computer such
as those based on in Intel PENTIUM.RTM.-type processor, a Motorola
PowerPC.RTM. processor, a Hewlett-Packard PA-RISC.RTM. processor, a
Sun UltraSPARC.RTM. processor, or any other type of processor or
combination thereof. Alternatively, the computer system may include
specially-programmed, special-purpose hardware, for example, an
application-specific integrated circuit (ASIC) or controllers
intended for fluid delivery systems.
[0061] The computer system can include one or more processors
typically connected to one or more memory devices, which can
comprise, for example, any one or more of a disk drive memory, a
flash memory device, a RAM memory device, or other device for
storing data. The memory is typically used for storing programs and
data during operation of the system. For example, the memory may be
used for storing historical data relating to the parameters over a
period of time, as well as operating data. Software, including
programming code that implements embodiments of the invention, can
be stored on a computer readable and/or writeable nonvolatile
recording medium, and then typically copied into memory wherein it
can then be executed by one or more processors. Such programming
code may be written in any of a plurality of programming languages,
for example, Java, Visual Basic, C, C#, or C++, Fortran, Pascal,
Eiffel, Basic, COBAL, or any of a variety of combinations
thereof.
[0062] Components of the computer system may be coupled by one or
more interconnection mechanisms, which may include one or more
busses, e.g., between components that are integrated within a same
device, and/or a network, e.g., between components that reside on
separate discrete devices. The interconnection mechanism typically
enables communications, e.g., data, instructions, to be exchanged
between components of the system.
[0063] The computer system can also include one or more input
devices, for example, a keyboard, mouse, trackball, microphone,
touch screen, and other man-machine interface devices as well as
one or more output devices, for example, a printing device, display
screen, or speaker. In addition, the computer system may contain
one or more interfaces that can connect the computer system to a
communication network, in addition or as an alternative to the
network that may be formed by one or more of the components of the
system.
[0064] According to one or more embodiments of the invention, the
one or more sensors for measuring any one or more parameters of the
system and/or components may be connected to a communication
network that is operatively coupled to the computer system. Any one
or more of the above may be coupled to another computer system or
component to communicate with the computer system over one or more
communication networks. Such a configuration permits any sensor or
signal-generating device to be located at a significant distance
from the computer system and/or allow any sensor to be located at a
significant distance from any subsystem and/or the controller,
while still providing data therebetween. Such communication
mechanisms may be affected by utilizing any suitable technique
including but not limited to those utilizing wireless
protocols.
[0065] The controller can include one or more computer storage
media such as readable and/or writeable nonvolatile recording
medium in which signals can be stored that define a program to be
executed by one or more processors. The medium may, for example, be
a disk or flash memory. In typical operation, the one or more
processors can cause data, such as code that implements one or more
embodiments of the invention, to be read from the storage medium
into a memory that allows for faster access to the information by
the one or more processors than does medium.
[0066] Although the computer system is described by way of example
as one type of computer system upon which various aspects of the
invention may be practiced, it should be appreciated that the
invention is not limited to being implemented in software, or on
the computer system as exemplarily shown. Indeed, rather than
implemented on, for example, a general purpose computer system, the
controller, or components or subsections thereof, may alternatively
be implemented as a dedicated system or as a dedicated programmable
logic controller (PLC) or in a distributed control system. Further,
it should be appreciated that one or more features or aspects of
the invention may be implemented in software, hardware or firmware,
or any combination thereof. For example, one or more segments of an
algorithm executable by a controller can be performed in separate
computers, which in turn, can be communication through one or more
networks.
[0067] Further aspects of the invention can involve or be directed
to computer-readable media, or providing computer-readable media,
that facilitates the various features of the delivery system
described herein, including a computer readable medium that can
instruct a controller to perform a method of wastewater odor
control. The method can include generating at least one first
control signal in a treating mode, generating at least one second
control signal in a flushing mode, identifying a first triggering
condition that initiates generation of the second control signal,
and identifying a second triggering condition that re-initiates
generation of the first control signal. Identifying the first
triggering condition can include monitoring a duration of an
elapsed treating time during which the first control signal is
generated, and comparing the duration of the elapsed treating time
to a target treating period. In addition or in the alternative,
identifying the first triggering condition can include measuring a
flowrate of the treating slurry introduced into the wastewater, and
comparing the measured flowrate to an expected flowrate of the
treating slurry to be introduced into the wastewater. Identifying
the second triggering condition can include monitoring a duration
of an elapsed flushing time during which the second control signal
is generated, and comparing the duration of the elapsed flushing
time to a target flushing period.
[0068] FIG. 2 is a flowchart that exemplarily depicts the operation
of one or more systems and techniques according to one or more
embodiments of the invention. Although the operation of the system
is described primarily with respect to a water treatment method or
routine that may be executed by one or more controllers (e.g.,
controller 118 of FIG. 1), it should be appreciated that the
invention is not so limited, and many of the steps described below
may be implemented manually, by a person, for example, rather than
by one or more electronic, mechanical or electromechanical devices,
as discussed in more detail further below. Further other systems
and techniques of the invention can be implemented to facilitate
treatment or control of addition of one or more reactant species,
effect or control a reaction, regulate activity of one or more
subsystems, and/or provide a desired condition of the wastewater to
be treated, based on one or more characteristic functions.
[0069] Prior to entering the routines of FIG. 2, a user is
typically requested to input metrics based on a current, desired,
and/or acceptable quality of the wastewater stream to be treated,
or a current, desired, and/or acceptable quality of the conduits
for delivering the treating slurry to the wastewater stream.
Characteristics or parameters of the system that may be inputted
can be, for example, times associated with a treating routine that
allows for delivery of the treating slurry, and times associated
with one or more flushing routines, for example a forward flushing
routine and a reverse flushing routine. Other characteristics or
parameters may include pH, flowrate, temperature, concentration or
weight percent of the source of the slurry may also be inputted at
this time. For example, the user may be prompted to enter natural
parameters pertaining to the water system such as the water volume
and/or concentration of disinfecting species to be added as well as
parameters related to a desired water quality such as, but not
limited to, maximum and/or minimum allowed values for the pH of the
wastewater to be treated or a target pH as well as an acceptable
range or tolerance by which the pH value may fluctuate, maximum
and/or minimum values for the concentration of one or more treating
slurries or a target concentration of one or more treating slurries
as well as a tolerance by which such concentrations can rise and
fall. Where there are applicable mandated municipal, state, federal
or other government requirements or guidelines, or where there are
safety and/or environmental requirements or guidelines, such values
may likewise be entered. It should be appreciated that other
parameters may be entered such as, but not limited to, the
estimated flow rate of a stream comprised of the water to be
treated or make up water, as the invention is not limited to a
particular set of metrics. Moreover, physical parameters that may
impact treatment, such as a tolerable delay or smoothing time may
likewise be entered.
[0070] At step 272, the treatment routine 270 can be initiated to
allow delivery of the treating slurry to the wastewater stream. The
treatment routine monitors the time elapsed at step 274. Other
various parameters of the system may be measured, for example, by
one or more of the plurality of sensors. Other parameters that may
be measured at step 274 may include, but are not limited to, the
temperature of the water, the oxidation-reduction potential of the
water, the pH of the water, the concentration of the treating
slurry in the water, or any combination of these parameters. Other
parameters that may be measured at step 274 may include, for
example, operational information such as flow rate or fluid level.
One or more of the measured parameters of the water system may be
temporarily stored in the memory of the controller (e.g., RAM),
and/or stored in a less volatile form of memory of the controller,
for example, a storage system, to use as historical data which may
be utilized to effect various operations of the controller, as
discussed more fully below. In some cases, one or more of the
measured parameters can be directed to one or more output devices,
which can, for example, print and/or transmit the one or more
measured values to one or more locally and/or remotely located
systems, facilities, and/or stations. For example, the output
device can comprise a communication device, such as a transmitter,
that can effect a wired or wireless link or connection so that the
value of one or more measured parameters, which can be raw,
analyzed, or normalized, can be received or collected by one or
more corresponding receiving devices.
[0071] After monitoring the treating time and, optionally,
measuring any other properties of the system, the routine typically
proceeds to step 276, wherein the existing or current treating time
or other measured parameter is verified to assess whether a change
is appropriate. Time or measured parameter verification can be
performed by comparing time or one or more measured parameters to
the user entered input metrics or a corresponding calculated or
expected value. In particular, at step 276, the routine can
determine whether a change to a different routine is appropriate.
The routine assesses whether a triggering condition is present such
as whether the current elapsed time is the inputted elapsed time,
and if the current elapsed time is not the same as the inputted
elapsed time, for example, less than the inputted elapsed time,
then the routine moves on to step 278 to determine a treating agent
setpoint. The treating agent setpoint may be based on one or more
particular characteristics of the system, for example, the time of
day, the pH of the wastewater stream, the flowrate of the
wastewater stream, or the temperature of the wastewater stream or
the temperature of the treating slurry. The setpoint can further be
adjusted based on one or more particular characteristics of the
system, for example, the pH of the wastewater stream, the flowrate
of the wastewater stream, or the temperature of the wastewater
stream or the temperature of the treating slurry. Once the setpoint
has been determined, the pump is energized and treating agent is
added in step 280, based on the treating agent setpoint, and the
routine returns to step 276 to again ascertain as to whether a
change to a different routine is appropriate, e.g., whether another
triggering condition is present. If the current elapsed time is the
same as the inputted elapsed time, the routine proceeds to a new
routine, for example the forward flushing routine 282. If the
current elapsed time is not the same as the inputted elapsed time,
the routine proceeds to steps 278 and 280, and then again returns
to step 276.
[0072] Once the forward flushing routine 282 is initiated in step
284, the pump is energized and flushing fluid is added to the
system in step 286. In step 288, the forward flushing time is
monitored, and optionally, any other properties of the system are
measured. The routine typically proceeds to step 290, wherein the
existing or current treating time or other measured parameter is
verified to assess whether a change is appropriate. Time or
measured parameter verification can be performed by comparing time
or one or more measured parameters to the user entered input
metrics or a corresponding calculated or expected value. Based on
whether the appropriate flushing time has elapsed, the routine will
either return to step 286 to add more flushing fluid, or proceed to
a new routine, for example the reverse flushing routine 292, which
initiates a similar routine as routine 282 using steps 294 through
300 to flush the system in the reverse direction. The existing or
current treating time or other measured parameter is verified in
step 300 to assess whether a change is appropriate. Based on
whether the appropriate flushing time has elapsed, the routine will
either return to step 296 to add more flushing fluid, or proceed to
a new routine, for example the treating routine 270.
Example
[0073] The function and advantages of these and other embodiments
of the invention can be further understood from the example below,
which illustrates the utility of the one or more systems and
techniques of the invention but do not exemplify the full scope of
the invention.
[0074] This example demonstrates the utility of a flushing system
of the present invention that is implemented in a wastewater
treatment system that successfully controls odor downstream of the
system.
[0075] A treating slurry at a concentration of 35 weight % solids
was added at a lift station to control hydrogen sulfide emission
from a wastewater stream at the list station and downstream of the
station. The treating slurry feed rate is dependent, at least, on
the wastewater flowrate. Additional factors may include turbulence,
temperature, influent dissolved sulfides and alkalinity of the
wastewater.
[0076] The treating slurry feed system was constructed and
installed at the lift station site. This consisted of a 6150 gallon
storage tank, treating slurry mixing system, peristaltic pump,
VersaDose.TM. controller from Siemens Water Technologies Corp., and
a pH monitor. The treating slurry feed line was placed to feed into
a manhole about 50 feet upstream of the lift station. The treating
slurry feed at room temperature typically exhibited a pH of
12.4.
[0077] A 35 weight % treating slurry comprising calcium hydroxide
was delivered to the site and fed on a dosing curve. Feed continued
for 3 weeks when the feed control was changed to be driven by the
pH of the wastewater entering the lift station. Over the next few
weeks, the controller pH set point was adjusted upward until the
desired atmospheric pH was attained.
[0078] Once a pH set point was established and the required
treating slurry feed was determined, a slug of ten gallons of 50%
anthraquinone was added at the manhole to determine the effect of
adding anthraquinone in concert with the treating slurry.
[0079] To improve material handling, the treating slurry was
changed to a 25 weight % solids slurry. Approximately 4000 gallons
of treating slurry was contained within the storage tank, and
mixing of the treating slurry occurred intermittently, as needed.
The tank was also periodically rinsed to remove solids build-up on
the sides of the tank to prevent precipitation and agglomeration
that could contribute to clogging of the system. Water and calcium
hydroxide was added to the tank as necessary. The pH was monitored
and the feed rate was adjusted based on the pH. Additionally, the
flowrate of the treating slurry was measured and compared to a
calculated feed rate based on the measured treating slurry tank
level to detect clogging of the conduits of the system. Flushing
time intervals and time periods were adjusted based on the
detection of clogging within the system. The conduits of the system
were flushed with water at various intervals and for various
periods of time to determine optimal flushing operating conditions.
For this particular system, it was determined that optimal treating
periods were in the range of from about 30 minutes to about 120
minutes. It was also determined that optimal forward flush periods
were in the range of from about 60 seconds to 120 seconds, and
reverse flush periods were in the range of from about 60 seconds to
about 120 seconds. For example, the following table depicts
flushing intervals and time periods tested.
TABLE-US-00001 TABLE 1 Flushing operating conditions tested
Treating Period Forward Flush Period Reverse Flush Period Test
(min.) (min.) (min.) 1 60 120 120 2 90 120 120 3 90 16 120 4 90 26
180 5 90 26 180 6 120 26 180 7 120 26 180 8 60 30 180 9 60 30 120
10 60 35 120 11 60 240 120 12 60 250 120 13 15 60 60 14 15 90 90 15
15 120 180 16 15 120 170 17 15 720 180 18 15 35 180 19 60 60 60 20
60 60 180 21 30 60 60 22 25 60 60
[0080] The odor at a downstream lift station was observed to be
less by utilizing the odor control system. It is believed that the
flushing system utilized contributed to the successful control of
odor because the system is able to operate with minimal
interruption that can be typically associated with manual flushing
of the system.
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