U.S. patent application number 14/215866 was filed with the patent office on 2015-09-17 for integrated smoke monitoring and control system for flaring operations.
This patent application is currently assigned to Honeywell International Inc.. The applicant listed for this patent is Honeywell International Inc.. Invention is credited to Bilal Abdallah, Annemarie Diepenbroek, Mohamed M. Ibrahim, Chinmaya Kar, Viswanath Talasila, Vijendran G. Venkoparao.
Application Number | 20150260397 14/215866 |
Document ID | / |
Family ID | 54068487 |
Filed Date | 2015-09-17 |
United States Patent
Application |
20150260397 |
Kind Code |
A1 |
Talasila; Viswanath ; et
al. |
September 17, 2015 |
INTEGRATED SMOKE MONITORING AND CONTROL SYSTEM FOR FLARING
OPERATIONS
Abstract
A flare monitoring and control system monitors parameters that
affect the amount of smoke generated during a flaring operation.
The system receives data relating to the parameters, and analyzes
the data relating to the parameters. The system predicts an
impending increase in the amount of smoke generated during the
flaring operation, and varies a value of one or more parameters to
prevent the impending increase in the amount of smoke generated
during the flaring operation.
Inventors: |
Talasila; Viswanath;
(Bangalore, IN) ; Kar; Chinmaya; (Bangalore,
IN) ; Ibrahim; Mohamed M.; (Kayalpatnam, IN) ;
Venkoparao; Vijendran G.; (Bangalore, IN) ;
Diepenbroek; Annemarie; (Sydney, NJ) ; Abdallah;
Bilal; (Khobar, SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Honeywell International Inc. |
Morristown |
NJ |
US |
|
|
Assignee: |
Honeywell International
Inc.
Morristown
NJ
|
Family ID: |
54068487 |
Appl. No.: |
14/215866 |
Filed: |
March 17, 2014 |
Current U.S.
Class: |
431/14 ; 431/15;
431/202 |
Current CPC
Class: |
F23G 2207/10 20130101;
F23N 5/18 20130101; F23N 2229/20 20200101; F23N 2223/08 20200101;
F23G 2207/112 20130101; F23N 2241/12 20200101; F23G 7/085 20130101;
F23N 5/003 20130101; F23N 5/242 20130101; F23N 2239/04 20200101;
F23N 5/022 20130101; F23G 2208/10 20130101; F23G 2209/141 20130101;
F23N 2231/10 20200101 |
International
Class: |
F23N 5/24 20060101
F23N005/24; F23N 5/18 20060101 F23N005/18; F23N 5/02 20060101
F23N005/02; F23G 7/08 20060101 F23G007/08; F23N 5/00 20060101
F23N005/00 |
Claims
1. A flare monitoring and control system comprising: a computer
processor operable to: monitor a plurality of parameters, the
parameters affecting an amount of smoke generated during a flaring
operation; receive data relating to the plurality of parameters;
analyze the data relating to the plurality of parameters; predict
an impending increase in the amount of smoke generated during the
flaring operation; and vary a value of one or more parameters to
prevent the impending increase in the amount of smoke generated
during the flaring operation.
2. The flare monitoring and control system of claim 1, wherein the
computer processor is operable to suggest preventative actions to
eradicate or decrease the impending increase in the amount of smoke
generated during the flaring operation.
3. The flare monitoring and control system of claim 1, wherein the
prediction of the impending increase in the amount of smoke
generated during the flaring operation is based on an
identification of a valve failure, a compressor problem, or a
suboptimal gas composition with respect to combustibility.
4. The flare monitoring and control system of claim 3, wherein the
identification of the compressor problem comprises one or more of a
shaft failure, a bearing failure, a blade failure, a surge failure,
a motor failure, and a gear failure.
5. The flare monitoring and control system of claim 4, wherein the
compressor problem comprises a time lag between the compressor
problem and starting a standby compressor, and wherein the computer
processor is configured to cause the standby compressor to start
immediately after the identification of the compressor problem.
6. The flare monitoring and control system of claim 1, wherein the
system monitors and controls an industrial plant.
7. The flare monitoring and control system of claim 6, wherein the
industrial plant comprises an oil or gas refinery or an oil or gas
separation plant.
8. The flare monitoring and control system of claim 1, wherein the
monitoring of the plurality of parameters comprises monitoring a
composition of a flare gas, and wherein the computer processor is
configured to inject one or more gases into the flare gas to modify
the composition of the flare gas.
9. The flare monitoring and control system of claim 1, wherein the
monitoring of the plurality of parameters comprises monitoring
steam/air injection quantity and quality, and wherein the computer
processor is configured to modify the steam/air injection
quantity.
10. The flare monitoring and control system of claim 1, wherein the
monitoring of the plurality of parameters comprises a first
monitoring of a flare image, a temperature at a liquid propane gas
(LPG) discharge, a LPG flow rate, an air/steam injection rate, an
air/steam quality, and a steam temperature; and wherein the
computer processor is configured to modify one or more of the LPG
flow rate, the air/steam injection rate, and the air/steam quality
as a function of the first monitoring.
11. The flare monitoring and control system of claim 1, wherein the
monitoring of the plurality of parameters comprises a second
monitoring of a compressor; and wherein the second monitoring of
the compressor involves one or more of vibration, noise, current,
speed, radar signal, flow, discharge pressure, ambient pressure,
discharge temperature, and ambient temperature; and wherein the
computer processor is configured to modify one or more of a
compressor inlet guide vane (IGV) angle, a compressor bleeding, and
a compressor motor speed or frequency as a function of the second
monitoring.
12. A flare monitoring and control process comprising: monitoring a
plurality of parameters, the parameters affecting an amount of
smoke generated during a flaring operation; receiving data relating
to the plurality of parameters; analyzing the data relating to the
plurality of parameters; predicting an impending increase in the
amount of smoke generated during the flaring operation; and varying
a value of one or more parameters to prevent the impending increase
in the amount of smoke generated during the flaring operation.
13. The flare monitoring and control process of claim 12,
comprising suggesting preventative actions to eradicate or decrease
the impending increase in the amount of smoke generated during the
flaring operation.
14. The flare monitoring and control process of claim 12, wherein
the predicting the impending increase in the amount of smoke
generated during the flaring operation is based on an
identification of a valve failure, a compressor problem, or a
suboptimal gas composition with respect to combustibility; wherein
the identification of the compressor problem comprises one or more
of a shaft failure, a bearing failure, a blade failure, a surge
failure, a motor failure, and a gear failure; and wherein the
compressor problem comprises a time lag between the compressor
problem and starting a standby compressor, and wherein the computer
processor is configured to cause the standby compressor to start
immediately after the identification of the compressor problem.
15. The flare monitoring and control process of claim 12,
comprising monitoring and controlling an industrial plant; wherein
the industrial plant comprises an oil or gas refinery or an oil or
gas separation plant.
16. The flare monitoring and control process of claim 12, wherein
the monitoring of the plurality of parameters comprises monitoring
a composition of a flare gas, and comprising injecting one or more
gases into the flare gas to modify the composition of the flare
gas.
17. A computer readable medium comprising instructions to execute a
flare monitoring and control process comprising: monitoring a
plurality of parameters, the parameters affecting an amount of
smoke generated during a flaring operation; receiving data relating
to the plurality of parameters; analyzing the data relating to the
plurality of parameters; predicting an impending increase in the
amount of smoke generated during the flaring operation; and varying
a value of one or more parameters to prevent the impending increase
in the amount of smoke generated during the flaring operation.
18. The computer readable medium of claim 17, comprising monitoring
steam/air injection quantity and quality; and modifying the
steam/air injection quantity.
19. The computer readable medium of claim 17, wherein the
monitoring of the plurality of parameters comprises a first
monitoring of a flare image, a temperature at a liquid propane gas
(LPG) discharge, a LPG flow rate, an air/steam injection rate, an
air/steam quality, and a steam temperature; and modifying one or
more of the LPG flow rate, the air/steam injection rate, and the
air/steam quality as a function of the first monitoring.
20. The computer readable medium of claim 17, wherein the
monitoring of the plurality of parameters comprises a second
monitoring of a compressor; and wherein the second monitoring of
the compressor involves one or more of vibration, noise, current,
speed, radar signal, flow, discharge pressure, ambient pressure,
discharge temperature, and ambient temperature; and modifying one
or more of a compressor inlet guide vane (IGV) angle, a compressor
bleeding, and a compressor motor speed or frequency as a function
of the second monitoring.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the monitoring and
controlling of flaring operations in industrial plants.
BACKGROUND
[0002] A flare is a pressure safety relief device used to ensure
that emergencies occurring in a plant (e.g., process upsets,
compressor failures, etc.) do not compromise the safety and
integrity of the plant. Such emergencies may require disposal of
large volumes of hydrocarbons, and flaring is the best and
practically the only option in these situations. Furthermore, at
times, as part of a refining process, more fuel gas (e.g., propane,
butane) is produced than needed by the plants. Flaring eliminates
this excess process gas by burning it off rather than venting
potentially damaging hydrocarbons to the atmosphere.
[0003] In industry today, as far as it is possible, flaring is
avoided to prevent loss of valuable hydrocarbons as well as to
minimize environmental damage. The flaring process introduces two
major sources of pollution--smoke and noise. These two pollutants
are strictly monitored by various environmental agencies, and there
is an economical and societal need to reduce this significantly
through improved monitoring and control.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a block diagram of a root cause analysis for smoke
formation in a flaring operation.
[0005] FIG. 2 is a block diagram illustrating a monitoring system
and various monitoring parameters for flare monitoring, compressor
monitoring, and gas composition monitoring.
[0006] FIG. 3 is a flowchart of a monitoring and control system for
a flaring operation in an industrial plant.
DETAILED DESCRIPTION
[0007] In the following description, reference is made to the
accompanying drawings that form a part hereof, and in which is
shown by way of illustration specific embodiments which may be
practiced. These embodiments are described in sufficient detail to
enable those skilled in the art to practice the invention, and it
is to be understood that other embodiments may be utilized and that
structural, electrical, and optical changes may be made without
departing from the scope of the present invention. The following
description of example embodiments is, therefore, not to be taken
in a limited sense, and the scope of the present invention is
defined by the appended claims.
[0008] The present disclosure presents a comprehensive solution for
monitoring and controlling flaring operations. A root cause
analysis of various factors that necessitate flaring and the
specific factors that cause extensive environmental damage is
presented. An embodiment reduces the effects of the variables (or
sub systems) that are responsible for flaring and pollution.
[0009] There are several issues that many industrial plants have to
deal with today. One is the generation of heavy smoke during
flaring operations. Because of this heavy smoke, many industrial
plants are unable to meet strict environmental regulations. At
least one cause of the heavy smoke is an ineffective smoke control
system. Another issue is a lack of an automated monitoring solution
for compressors, valves, etc. In an embodiment, compressors are
monitored so as to prevent compressor failures, which will minimize
flaring. Another issue is the lack of online gas composition
estimation tools as part of the overall smoke control. In an
embodiment, gas composition is monitored, and if the composition is
detected as suboptimal (for good combustibility), an appropriate
gas mixture is added. Another issue is the significant financial
losses due to flaring and compressor problems.
[0010] In an embodiment, several modules can be integrated into a
flare monitoring and control system. The system can include a
monitoring module, relating to at least health monitoring and asset
monitoring. The system can also include a machinery control system.
The system can further include a field advisor that can monitor the
performance of various process and equipment parameters.
[0011] In many industrial plants today, existing smoke control
systems include steam injection. Such systems are automated, and
the smoke detection is performed using infrared (IR) cameras. Some
plants use air-assisted control. However, such control systems are
not efficient for several reasons. One reason is that such systems
do not take any inputs from other parts of the plant, for example,
compressors, valves, etc. Also, for systems that use IR cameras,
the control system takes input from the IR camera, which examines
the flare (controller is tuned with a simple rule that large flares
imply large smoke, and the converse), and releases an appropriate
amount of steam. Such a control action is reactive in the sense
that excess flaring or smoke is caused due to various
processes/equipment behaving sub-optimally--and the smoke is the
end result of complex failures in the plant or refinery. Also, the
control system can react only after smoke detection. Consequently,
there is a significant delay in control after the plant upsets,
which usually renders control ineffective. Thus, there is a need
for advanced monitoring techniques which can predict critical
failures in industrial and refinery processes and equipment, and
inform the control system of impending failures so that the control
system can respond better.
[0012] Consequently, one or more goals of one or more embodiments
include that the smoke that is generated during flaring should be
reduced and/or eliminated, compressor reliability should be
improved, and compressor tripping should be capable of prediction
so that lag time (usually about thirty minutes to an hour) between
the compressor tripping and a standby compressor starting should be
reduced. Addressing the issues of compressor reliability and trip
prediction will also help in reducing the smoke problem. Further,
one or more embodiments include that the gas composition monitoring
be made online and included in the overall smoke control loop.
[0013] A root cause analysis (with top-down approach) of smoke
formation can be used to investigate the generation of smoke during
flaring operations. The results of the root cause analysis can then
be used to address the issues enumerated in the previous paragraph.
FIG. 1 is a block diagram for a root cause analysis for smoke
formation during a flaring operation.
[0014] Referring to FIG. 1, the analysis begins at 110 with the
premise that there is a good deal of smoke and indeed too much
smoke during flaring operations. This large amount of smoke during
flaring can be contributed to and/or caused by at least three major
causes. First, at 120, the amount of flare gas can be large. Of
course, the more gas that there is to flare off, then the more
smoke will be generated. Second, at 130, the composition of the
particular gas that is being flared could create more or less smoke
than other gases. Third, at 140, in systems that use steam/air
injection, the quantity and quality of the steam/air could be
insufficient, thereby leading to unacceptable levels of smoke.
[0015] There are several reasons the amount of flare gas could be
large at 120. The large amount of flare gas could be the result of
a valve failure as indicated at 123, or it could be the result of
issues with a compressor at 125. The compressor issues at 125 could
further be the result of compressor reliability issues at 127,
which in turn could be the result of a shaft failure (127A), a
bearing failure (127B), a compressor blade failure (127C), a
surging failure (127D), a motor failure (127E), and/or a gear
failure (127F). The compressor issues at 125 could also be the
result of a time lag between a compressor tripping and the starting
of a standby compressor, as indicated at 129. As illustrated at
129A, this lag time could be because a tripping prediction system
is not in place. Additionally, as indicated at 129B, there may be
no automatic way of starting the standby compressor when there is
tripping. That is, the standby compressor must be manually
started.
[0016] Regarding smoke creation from the gas composition at 130,
the gas composition may not be monitored as indicated at 131, and
the heating value of the gas could reduce combustion efficiency as
indicated at 132. Both the gas composition and heating value of the
gas can contribute to increased smoke during flaring.
[0017] Finally, the quantity and quality of the steam/air in an
injection system could be insufficient. As illustrated at 142, the
amount of steam or air that is provided may not be controlled in
real time. Additionally, as indicated at 144, there may be
reliability issues with an air compressor, a nozzle, or a
valve.
[0018] The root cause analysis of FIG. 1 shows that there are at
least three reasons for (excessive) smoke formation. First, and
more specifically, there will likely be excessive smoke formation
when large volumes of flare gas are suddenly vented to the flare
stack due to plant upsets. Second, the composition of the flare gas
or its heating value affects the amount of smoke formation. Third,
the availability of sufficient control of steam/air flow affects
the amount of smoke formation.
[0019] There are three typical flows to the flare system. First,
there are emergency flows. Examples of an emergency flow include
pressure relief flows and emergency depressurization. Second, there
are episodic flows. Examples of episodic flows include venting that
is required for maintenance, and venting that is required for
regeneration and shutdown/startup operations. Third, there are
continuous flows. Examples of continuous flow are a sweep gas that
is put through the flare system piping, and pressure relief valve
leakages. In any of these typical flows to the flare system, the
amount of flare gas that is vented depends on the extent of valve
failures, compressor failures, and/or process upsets. For example,
if during normal conditions the flare gas flows at 4-6 million
cubic feet per minute (mmcfm), and the compressor trips, the flare
gas flow can increase to 150 mmcfm. This increase can cause
excessive flaring and result in smoke and noise formation.
[0020] Compressor tripping can happen because of various individual
component failures. When a compressor does trip, a standby
compressor is started. Thereafter, it can take 30-60 minutes to
reach steady state operating conditions. During this 30-60 minute
period, the flaring can become very large.
[0021] When the flare gas is comprised of individual gases with
high molecular weight, the smoke becomes thicker and black.
However, when the flare gas is comprised of gases of lower
molecular weight, the smoke becomes white and thinner. For example,
ethylene (molecular weight-18 28) produces lighter smoke compared
to butadiene (molecular weight.about.54). Also, the gas composition
changes the heating value of the gas, thereby affecting the
combustion efficiency, resulting in higher levels of smoke
creation. The steam quality with dryness factor and temperature can
also affect the quality of the smoke.
[0022] The quantity and/or quality of steam or air plays an
important role in the formation of the smoke. The failure of an air
compressor or nozzle can cause excessive smoke formation.
[0023] An embodiment addresses the various factors that cause smoke
and noise formation by integrating monitoring and control. In the
monitoring part of the system, there are several parameters of
interest. First, there is the reliability of the compressors.
Compressor reliability is monitored by analyzing a compressor's
vibration, noise, motor current, speed, performance parameters,
etc. Second, there is the composition of the flare gas. There exist
a few online techniques for detecting gas composition that are
known to those of skill in the art. One technique uses an infrared
(IR) sensor with appropriate filters for detecting spectral
responses of various gases. In another embodiment, catalytic type
combustible sensors are used. Laser gas detection systems are
another option for gas sensing. Finally, solid state sensors can be
used. Thus, there are a wide variety of options for online gas
(composition) sensing in refineries and other industrial plants.
Third, the monitoring involves monitoring steam quantity, steam
quality, and air flow. Fourth, the monitoring involves flare and
smoke monitoring. For smoke and/or flare detection, the two
standard approaches include using an IR sensor and a normal
charge-coupled device (CCD) sensor.
[0024] FIG. 2 illustrates a monitoring system 202A, 202B and
controlling parameters 204 for a flaring operation system 200. The
monitoring system 202A, 202B includes flare monitoring 232,
compressor monitoring 234, and gas composition monitoring 236. Data
that are input into the monitoring system 202A, 202B, and in
particular the flare monitoring 232, include flare images 210,
temperature at a liquid propane gas (LPG) discharge 211, an LPG
flowrate 212, an air/steam injection rate 213, a steam quality 214,
and a steam temperature 215. Data that are input into the
compressor monitoring 234 include vibration, noise, motor current,
speed, and radar signal 216, flow 217, discharge pressure 218,
ambient pressure 219, ambient air flow 219A, discharge temperature
220, and ambient temperature 221. Gas data 222 are input into gas
composition monitoring 236.
[0025] Based upon the data input into the monitoring system
(210-222), and in particular, the amount of smoke or flaring (210),
the various controlling parameters (251-258) are activated so as to
control the smoke or flare. For example, if the pilot flame is
visible (a blue color when LPG is used) during zero or low flaring,
then the LPG flow rate (251) could be adjusted based on the
requirement. Otherwise, the temperature of the pilot flame (211)
(measured via thermocouples) can also be used for controlling the
LPG flow rate. Similarly, if there is a large amount of smoke, then
the steam/air quality (253, 254) and quantity (252) can be varied.
The quality of air (253) can be controlled by providing an
appropriate amount of oxygen or any other gas. The composition of
the gas can also be varied using similar methods (258). The
compressor control systems can be surge controlling, where the flow
has to be varied using bleeding (256) or varying inlet guide vane
(IGV) angle (255) or changing speed (257). Therefore, an embodiment
using the integrated controls of FIG. 2 is effective for tackling
various types of and reasons for smoke.
[0026] As further illustrated in FIG. 2, a computer processor 250
executes the monitoring and control functions. The processor 250
receives input data from the monitoring system 202A via a sensor
260, and outputs control signals that affect the controlling
parameters 204. The input data from the monitoring systems 202A can
be stored in a database 270 for future consideration and analysis,
and the computer processor 250 can also output data, alarms,
reports, and other information to output device 280.
[0027] In summary, in the control system, the monitored variables
described above (210-222) form the inputs to the control system.
The control system executes the control of some compressor failure
modes like surge, the control of the flare smoke and noise (using
the air/steam control system (252, 253, 254)), and the control of
steam/air quality (253, 254). FIG. 2 is a centralized control
structure. In another embodiment, the monitoring and control system
is a distributed structure, wherein for example the compressor
control is local to the compressor location.
[0028] FIG. 3 is a flowchart of an example process 300 for
monitoring and controlling a flaring operation. FIG. 3 includes a
number of process and feature blocks 305-360. Though arranged
serially in the example of FIG. 3, other examples may reorder the
blocks, omit one or more blocks, and/or execute two or more blocks
in parallel using multiple processors or a single processor
organized as two or more virtual machines or sub-processors.
Moreover, still other examples can implement the blocks as one or
more specific interconnected hardware or integrated circuit modules
with related control and data signals communicated between and
through the modules. Thus, any process flow is applicable to
software, firmware, hardware, and hybrid implementations.
[0029] Referring to FIG. 3, at 305, a computer processor monitors
parameters affecting an amount of smoke generated during a flaring
operation. At 310, data relating to the parameters are received
into the computer processor. At 315, the computer processor
analyzes the data relating to the parameters. At 320, the computer
processor uses the data analysis to predict an impending increase
in the amount of smoke generated during the flaring operation. At
325, the computer processor varies a value of one or more
parameters to prevent or decrease the impending increase in the
amount of smoke generated during the flaring operation.
[0030] At 330, the computer processor suggests preventative actions
to eradicate or decrease the impending increase in the amount of
smoke generated during the flaring operation. The computer
processor may report to output device 280 that a liquid propane gas
flow rate (212) is either too low or two high, which may decrease
the efficiency of the plant, which in turn may increase the smoke
generated during flaring.
[0031] At 335, the prediction of an impending increase in the
amount of smoke generated during the flaring operation is based on
an identification of a valve failure or a compressor problem. As
indicated at 336, the identification of the compressor problem can
include a shaft failure, a bearing failure, a blade failure, a
surge failure, a motor failure, and/or a gear failure.
Additionally, as indicated at 337, the compressor problem can
include a time lag between the compressor problem and starting a
standby compressor. In an embodiment, this lag time issue can be
addressed by configuring a computer processor to cause a standby
compressor to start immediately or substantially immediately after
the identification of the compressor problem.
[0032] As indicated at 340, the flare monitoring and control system
can monitor and control an industrial plant, and as indicated at
341, the industrial plant can be an oil or gas refinery or an oil
or gas separation plant.
[0033] Block 345 indicates that the monitoring of the parameters
includes monitoring a composition of a flare gas, and that a
computer processor causes an injection of one or more gases into
the flare gas to modify the composition of the flare gas.
[0034] Block 350 indicates that the monitoring of the parameters
includes monitoring steam/air injection quantity and quality, and
that a computer processor causes a modifying of the steam/air
injection quantity.
[0035] Block 355 indicates that the monitoring of the parameters
includes a monitoring of a flare image, a temperature at a liquid
propane gas (LPG) discharge, a LPG flow rate, an air/steam
injection rate, an air/steam quality, and/or a steam temperature,
and that the computer processor causes a modifying of one or more
of the LPG flow rate, the air/steam injection rate, and the
air/steam quality as a function of the monitoring.
[0036] Block 360 indicates that the monitoring of the parameters
includes a monitoring of a compressor. Specifically, the monitoring
of the compressor includes the monitoring of one or more of
vibration, noise, current, speed, radar signal, flow, discharge
pressure, ambient pressure, discharge temperature, and ambient
temperature. The computer processor causes the modifying of one or
more of a compressor inlet guide vane (IGV) angle, a compressor
bleeding, and a compressor motor speed or frequency as a function
of the monitoring.
[0037] It should be understood that there exist implementations of
other variations and modifications of the invention and its various
aspects, as may be readily apparent, for example, to those of
ordinary skill in the art, and that the invention is not limited by
specific embodiments described herein. Features and embodiments
described above may be combined with each other in different
combinations. It is therefore contemplated to cover any and all
modifications, variations, combinations or equivalents that fall
within the scope of the present invention.
[0038] The Abstract is provided to comply with 37 C.F.R.
.sctn.1.72(b) and will allow the reader to quickly ascertain the
nature and gist of the technical disclosure. It is submitted with
the understanding that it will not be used to interpret or limit
the scope or meaning of the claims.
[0039] In the foregoing description of the embodiments, various
features are grouped together in a single embodiment for the
purpose of streamlining the disclosure. This method of disclosure
is not to be interpreted as reflecting that the claimed embodiments
have more features than are expressly recited in each claim.
Rather, as the following claims reflect, inventive subject matter
lies in less than all features of a single disclosed embodiment.
Thus the following claims are hereby incorporated into the
Description of the Embodiments, with each claim standing on its own
as a separate example embodiment.
* * * * *