U.S. patent application number 14/333637 was filed with the patent office on 2016-01-21 for boiler flue gas and oven exhaust economizer systems.
The applicant listed for this patent is Enervex Inc.. Invention is credited to Steen Hagensen, Bruce Works.
Application Number | 20160018113 14/333637 |
Document ID | / |
Family ID | 55074290 |
Filed Date | 2016-01-21 |
United States Patent
Application |
20160018113 |
Kind Code |
A1 |
Hagensen; Steen ; et
al. |
January 21, 2016 |
Boiler Flue Gas and Oven Exhaust Economizer Systems
Abstract
A representative mechanical draft system includes an in-line
draft inducer that comprises a motor and a backward-inclined
impeller. The mechanical draft system also includes an economizer
coupled to the in-line draft inducer, where the economizer
comprises a housing and a horizontally mounted heat recovery
unit.
Inventors: |
Hagensen; Steen; (Atlanta,
GA) ; Works; Bruce; (Atlanta, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Enervex Inc. |
Alpharetta |
GA |
US |
|
|
Family ID: |
55074290 |
Appl. No.: |
14/333637 |
Filed: |
July 17, 2014 |
Current U.S.
Class: |
122/20B ;
110/162; 126/312; 431/2 |
Current CPC
Class: |
Y02B 30/18 20130101;
Y02E 20/30 20130101; F23J 15/06 20130101; Y02E 20/363 20130101;
F24D 17/0005 20130101; F23L 17/005 20130101 |
International
Class: |
F24D 17/00 20060101
F24D017/00; F23L 13/00 20060101 F23L013/00; F23L 17/00 20060101
F23L017/00 |
Claims
1. A mechanical draft system, comprising: an in-line draft inducer
comprising a motor and a backward-inclined impeller; and an
economizer coupled to the in-line draft inducer, the economizer
comprising a housing and a horizontally mounted heat recovery
unit.
2. The system of claim 1, wherein the motor is a variable speed
motor and is mounted externally to a housing of the in-line draft
inducer.
3. The system of claim 1, wherein the economizer comprises at least
one bypass damper controlled by an actuator, wherein the actuator
is configured to control a position of the least one bypass damper
to control a flow of gases through the economizer.
4. The system of claim 3, wherein the at least one bypass damper
comprises a fin having a semi-circular cross section.
5. The system of claim 3, wherein the at least one bypass damper
comprises one of a butterfly damper and a multi-blade damper.
6. The system of claim 3, wherein the actuator is configured to
configure the at least one bypass damper in one of a neutral
position and a blocking position, wherein the neutral position
allows free flow of gases through the economizer, and wherein the
blocking position inhibits the flow of gases.
7. The system of claim 1, wherein the heat recovery unit comprises
a water-based radiator.
8. The system of claim 1, wherein the heat recovery unit is mounted
on a guide rail assembly within the economizer.
9. The system of claim 1, wherein the guide rail assembly is
horizontally disposed along a centerline of the economizer.
10. The system of claim 1, wherein the economizer further comprises
a tapered inlet for channeling exhaust flow.
11. The system of claim 1, wherein the tapered inlet is coupled to
a boiler unit and is configured to receive hot exhaust from the
boiler.
12. The system of claim 1, wherein the heat recovery unit comprises
rectangular plate fins and a plurality of die-extruded tube
collars.
13. A mechanical draft system, comprising: an in-line draft inducer
comprising a motor and a backward-inclined impeller; and an
economizer detachably coupled to the in-line draft inducer, the
economizer comprising a cylindrical housing for horizontally
mounting a heat recovery unit that partitions the housing into an
upper chamber and a lower chamber.
14. The system of claim 13, wherein the economizer further
comprises a dual-damper configuration controlled by separate
actuators, wherein each actuator is configured to control a
position of the corresponding damper to control exhaust flow
through the economizer.
15. The system of claim 14, wherein the actuator controls a
position of each damper to allow flue gases entering the economizer
to flow in one of two exhaust flow configurations, wherein the
first exhaust flow configuration comprises exhaust flow through
only one of the upper chamber and the lower chamber to bypass the
heat recovery unit, and wherein the second exhaust flow
configuration comprises turbulent exhaust flow through one of the
lower chamber and upper chamber, through the heat recovery unit,
and into the other chamber.
16. The system of claim 14, wherein the actuator is configured to
place each damper in one of a neutral position, a first blocking
position, and a second blocking position; wherein the neutral
position allows free exhaust flow, and wherein each of the first
and second blocking positions inhibits exhaust flow.
17. The system of claim 13, wherein the economizer further
comprises: a single damper disposed on one end of the economizer;
and a fixed end plate disposed on another end of the economizer;
wherein the damper is controlled by an actuator, wherein the
actuator is configured to control a position of the damper to
control exhaust flow through the economizer.
18. The system of claim 13, wherein the economizer comprises a
circular inlet and a circular outlet, wherein the circular inlet
and circular outlet each include mounting flange fittings.
19. A method implemented in a draft controller in a mechanical
draft system comprising an in-line draft inducer and an economizer,
the economizer comprising a heat recovery unit and a damper
assembly, the method comprising: in response to a heat recovery
request, increasing a fan speed of the in-line draft inducer based
on a predetermined draft set point value; upon reaching the draft
set point value, opening a valve of the economizer to allow fluid
to flow through the heat recovery unit; placing the damper assembly
in a closed position to channel exhaust flow through the heat
recovery unit; and in response to the damper assembly being placed
in a closed position, increasing the fan speed of the in-line draft
inducer to maintain the predetermined draft set point value.
20. The method of claim 19, further comprising: in response to a
temperature of the fluid flowing through the heat recovery unit
reaching a first predetermined temperature, placing the damper
assembly in a partially open position; and in response to a
temperature of the fluid flowing through the heat recovery unit
reaching a second predetermined temperature, placing the damper
assembly in a fully open position.
Description
BACKGROUND
[0001] There are many types of boilers, ovens, and other heat
generating appliances on the market that vent or exhaust
differently. An atmospheric boiler with a draft hood or draft
diverter relies on the natural draft, which typically range from
0.0 to 0.03 inch water column (inWC) draft. Even a small
restriction in the chimney flue can cause the boiler to fail or
prevent proper discharge of products of combustion.
[0002] A forced draft boiler used for steam or hot water has a
built-in fan to push products of combustion through the venting
system and the forced draft typically range from 0.0 to 0.5 inWC.
Other boiler types fall in between these two extremes. As a result,
it is generally a challenge to use flue gas economizers and they
are rarely used with atmospheric boilers. Economizers used with
forced draft boilers must generally be designed so that the
resistance never exceeds 0.3-0.4 inWC, thereby causing such
economizers to be voluminous and space consuming. This restriction
also limits the number of boilers a single economizer can serve.
Thus, in most applications, a dedicated economizer is needed for
each boiler even when exhausted through a single common
chimney.
[0003] Baking ovens and process ovens experience the same
challenges as boilers. Often, there is no driving force in the
exhaust stream, so it is very difficult to integrate a heat
recovery unit in the exhaust stream to recapture the heat in the
exhaust gases. In addition to the applications described above,
other processing equipment such as cooling systems, smokehouses,
drying equipment, brewing equipment, pasteurizers, etc. generate
hot exhaust. Most of these applications face serious challenges
when heat recovery is attempted, where such attempts often lead to
oven failures, unintended processing results, and so on. There is
therefore a need in the industry for devices capable of saving and
recovering energy.
SUMMARY
[0004] Various embodiments of a mechanical draft system are
disclosed. Briefly described, one embodiment of a mechanical draft
system includes an in-line draft inducer that comprises a motor and
a backward-inclined impeller. The mechanical draft system also
includes an economizer coupled to the in-line draft inducer, where
the economizer comprises a housing and a horizontally mounted heat
recovery unit.
[0005] Another embodiment of a mechanical draft system includes an
in-line draft inducer comprising a motor and a backward-inclined
impeller. The mechanical draft system also includes an economizer
detachably coupled to the in-line draft inducer, the economizer
comprising a cylindrical housing for horizontally mounting a heat
recovery unit that partitions the housing into an upper chamber and
a lower chamber.
[0006] Another embodiment is a method implemented in a draft
controller in a mechanical draft system comprising an in-line draft
inducer and an economizer, the economizer comprising a heat
recovery unit and a damper assembly. In response to a heat recovery
request, a fan speed of the in-line draft inducer is increased
based on a predetermined draft set point value. Upon reaching the
draft set point value, a valve of the economizer is opened to allow
fluid to flow through the heat recovery unit. The damper assembly
is placed in a closed position to channel exhaust flow through the
heat recovery unit, and in response to the damper assembly being
placed in a closed position, the fan speed of the in-line draft
inducer is increased to maintain the predetermined draft set point
value.
[0007] Other systems, methods, features, and advantages of the
present disclosure will be or become apparent to one with skill in
the art upon examination of the following drawings and detailed
description. It is intended that all such additional systems,
methods, features, and advantages be included within this
description, be within the scope of the present disclosure, and be
protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Many aspects of the disclosure can be better understood with
reference to the following drawings. The components in the drawings
are not necessarily to scale, emphasis instead being placed upon
clearly illustrating the principles of the present disclosure.
Moreover, in the drawings, like reference numerals designate
corresponding parts throughout the several views.
[0009] FIG. 1 illustrates a mechanical draft system that comprises
an economizer coupled to an in-line draft inducer according to
various embodiments of the present disclosure.
[0010] FIG. 2A illustrates a first exhaust flow configuration where
a turbulent exhaust flow is created such that flue gases flow
through the lower chamber, through the heat recovery unit, and then
into the upper chamber according to various embodiments of the
present disclosure.
[0011] FIG. 2B illustrates a second exhaust flow configuration
where the flue gases flow over and bypass the heat recovery unit
according to various embodiments of the present disclosure.
[0012] FIG. 3 is an exploded view of the in-line draft inducer of
FIG. 1.
[0013] FIG. 4A illustrates how the heat recovery unit is mounted on
a guide rail assembly within the economizer, where the guide rail
assembly is horizontally installed along a centerline of the
economizer.
[0014] FIG. 4B illustrates the heat recovery unit inserted into the
housing of the economizer and where the blades of the bypass damper
assembly are in a closed position to block the flow of flue gases
through the lower chamber of the economizer.
[0015] FIG. 5 illustrates NPT water connectors on a distal end of
the heat recovery unit.
[0016] FIG. 6 is a side view of the economizer of FIG. 1, where the
bypass damper assembly includes a series of lever arms that are
pivotally connected to the blades of the bypass damper
assembly.
[0017] FIG. 7 shows another embodiment of the bypass damper
assembly in the economizer, where the bypass damper assembly
comprises a single round damper blade.
[0018] FIG. 8 is a top view of the economizer and further
illustrates how the heat recovery unit is slidably inserted into
the economizer.
[0019] FIG. 9 is a side view of the economizer and further
illustrates how the heat recovery unit partitions the housing of
the economizer into an upper chamber and a lower chamber.
[0020] FIG. 10 is a flowchart illustrating an algorithm for
controlling the various components of the mechanical draft system
of FIG. 1 for facilitating the flow of flue gases according to
various embodiments of the present disclosure.
[0021] FIG. 11A illustrates how the economizer and the in-line
draft inducer are coupled together via a mating bolt flange and
where the mechanical draft system is attached to a chimney in a
substantially horizontal orientation according to various
embodiments of the present disclosure.
[0022] FIG. 11B illustrates how the economizer and the in-line
draft inducer are coupled together via mating bolt flanges and
where the mechanical draft system is attached to a chimney in a
substantially vertical orientation according to various embodiments
of the present disclosure.
[0023] FIG. 12 illustrates another configuration wherein the
economizer and the in-line draft inducer are separated from each
other in the chimney system according to various embodiments of the
present disclosure.
DETAILED DESCRIPTION
[0024] Embodiments of a mechanical draft system are disclosed that
comprise an economizer that may be either fan-powered with an
integrated draft fan or configured as a stand-alone unit. Reference
is made to FIG. 1, which depicts a mechanical draft system 102 that
comprises an economizer 104 coupled to an in-line draft inducer 110
according to various embodiments of the present disclosure. The
modulating fan-powered economizer 104 shown can be used in various
systems that include at least one appliance, such as, for example,
a boiler, oven, water heater, fireplace, and so on.
[0025] In the embodiment of FIG. 1, the economizer 104 includes an
inlet 101, an outlet 103 and a housing 105 positioned between the
inlet 101 and outlet 103. The inlet 101 and the outlet 103
facilitate the flow of flue gases entering the economizer 104. The
housing 105 may be constructed according to a round tube-type
design where the flow path through the housing 105 is linear. The
economizer 104 is equipped with a heat recovery unit 106 comprising
a radiator style heat recovery unit constructed with copper tubing
and fins. For other embodiments, the radiator style heat recovery
unit may be constructed with 316 stainless tubing and fins.
[0026] As shown, the heat recovery unit 106 is horizontally mounted
such that the main body portion of the heat recovery unit 106 is
perpendicular to the flue gas flow. The economizer 104 is further
equipped with a bypass damper assembly 108, where the bypass damper
assembly 108 may comprise a butterfly damper or a multi-blade
damper, as shown in FIG. 1. The bypass damper assembly 108 is
controlled by a variable position actuator in the economizer 104,
where the actuator configures the bypass damper assembly 108 to
direct the exhaust flow in one of two exhaust flow configurations.
In a first exhaust flow configuration, the flue gases flow pass
over and through the heat recovery unit 106. Specifically, a
turbulent exhaust flow is created such that flue gases flow through
the lower chamber, through the heat recovery unit 106, and into the
upper chamber, as shown in FIG. 2A.
[0027] In a second exhaust flow configuration, the flue gases flow
over and bypass the heat recovery unit 106, as shown in FIG. 2B.
This configuration prevents over-heating of the coils in case the
liquid inside the coils is not flowing or if the exhaust heat
exceeds the performance of the heat recovery unit 106. The
combination of the variable position actuator and the bypass damper
assembly 108 allow modulation of the exhaust air flow over the heat
recovery unit 106 so that a variable percentage of the exhaust air
can pass through the heat recovery unit 106 and the remainder
bypass the heat recovery unit 106.
[0028] Referring back to FIG. 1, a tapered inlet member 112 may be
coupled to the economizer 104 to further facilitate the channeling
of exhaust flow. The diameter of the tapered inlet member 112 is
constructed to allow the mechanical draft system 102 to be inserted
into any type of commercial chimney. As shown, the tapered inlet
member 112, the economizer 104, and the in-line draft inducer 110
may each include bolt flanges 113, 114, 115 for coupling the
tapered inlet member 112, the economizer 104, and the in-line draft
inducer 110 to each other.
[0029] Reference is made to FIG. 3, which is an exploded view of
the in-line draft inducer 110 of FIG. 1. The in-line draft inducer
110 may be installed in-line in the vertical or horizontal section
of a chimney or stack. In accordance with various embodiments, the
in-line draft inducer 110 includes a backward inclined centrifugal
impeller 112. The housing 119 of the in-line draft inducer 110 is
constructed of stainless steel and is equipped with an enclosed
variable speed motor. The centrifugal impeller 112 is an in-line
fan where the inlet and outlet are on the same centerline. With the
integration of a centrifugal impeller 112, the in-line draft
inducer 110 can handle a great deal of pressure resistance, which
is utilized in most applications to down-size ductwork. However,
the centrifugal may also be used to reduce the perceived resistance
in the economizer 104.
[0030] The backward inclined configuration of the centrifugal
impeller 112 places the motor on the outside of the air stream with
the centrifugal impeller 112 inside the housing 119, which is made
possible by installing the variable speed motor and centrifugal
impeller 112 at an angle. The variable speed motor and the
centrifugal impeller 112 form an integrated drive unit assembly
that can be removed from the housing 119 without removing the
entire in-line draft inducer 110 from the stack system. While FIG.
3 shows the in-line draft inducer constructed with bolt flanges
115, the in-line draft inducer may alternatively include slip
connection fittings.
[0031] FIGS. 4A and 4B further illustrate features of the heat
recovery unit 106 and the bypass damper assembly 108 of the
economizer 104 in FIG. 1. With reference to FIG. 4A, the heat
recovery unit 106 is mounted on a guide rail assembly 302 within
the economizer 104, where the guide rail assembly 302 is
horizontally installed along a centerline of the economizer 104.
The heat recovery unit 106 slides into the side of the housing 105
via the guide rail assembly 302 and a mounting flange secures the
heat recovery unit 106 to the housing 105 to prevent leakage.
[0032] It should be emphasized that while the heat recovery unit
106 is shown horizontally mounted in the economizer 104, the heat
recovery unit 106 may alternatively be vertically mounted in the
economizer 104. The heat recovery unit 106 includes a top face 310
and a bottom face (not shown) formed by a series of copper tubing
and fins. Referring briefly to FIG. 5, the heat recovery unit 106
also includes NPT (National Pipe Taper) water connectors 304 on a
distal end of the heat recovery unit 106.
[0033] The heat recovery unit 106 comprises rectangular plate fins
with a matrix of die-extruded tube collars. A sheet metal casing
provides rigidity to the fin-tube assembly prior to tube expansion.
After assembly, the tubes are expanded into the fin collars, which
allows for a gap-free connection maximizing heat recovery unit
performance and structural integrity. It should be appreciated that
the design is extremely compact and efficient, and the pressure
drop through the heat recovery unit may exceed 0.5 inWC.
[0034] Referring back to FIG. 4A, the bypass damper assembly 108
comprises a plurality of blades 308a, 308b, 308c that are
controlled by an actuator 301 configured to control a flow of gases
through the economizer 104 by controlling the position of each
blade 308a, 308b, 308c. FIG. 4A illustrates the blades 308a, 308b,
308c of the bypass damper assembly 108 in an open position to allow
flue gases to pass through the lower chamber formed by the heat
recovery unit 106 and the housing of the economizer 104 (when the
heat recovery unit 106 is fully inserted into the economizer 104.
FIG. 4B illustrates the heat recovery unit 106 inserted into the
housing 105 of the economizer 104 and the blades 308a, 308b, 308c
of the bypass damper assembly 108 in a closed position to block the
flow of flue gases through the lower chamber of the economizer
104.
[0035] Reference is made to FIG. 6, which is a side view of the
economizer 104. As shown, the bypass damper assembly 108 further
includes a series of lever arms 404a, 404b that are pivotally
connected to the blades 308a, 308b, 308c. The lever arms 404a, 404b
are coupled together via a connecting member 402. By controlling
the position of the lever arms 404a, 404b, the actuator 301 (FIG.
4A), is able to control the position of each blade 308a, 308b, 308c
and thus control the flow of flue gases through the chamber 410
formed by the heat recovery unit 106 and the housing of the
economizer 104.
[0036] FIG. 7 shows another embodiment of the bypass damper
assembly 108 in the economizer 104. For alternative embodiments,
the bypass damper assembly 108 may comprise multiple round
butterfly dampers, where the round damper blades are connected to a
central shaft. For other embodiments, the bypass damper assembly
108 may comprise a single round damper where the actuator 301 (FIG.
4A) controls the position of the round damper such that the round
damper is either in a neutral position or a blocking position,
where the neutral position allows free flow of gases through the
economizer 104, and where the blocking position inhibits the flow
of gases. As shown in FIG. 7, the bypass damper assembly 108 may
further comprise a fixed end plate 502 that is sealed. The fixed
end plate 502 forces the flue gases to flow over the heat recovery
unit when the damper assembly 108 is in a closed position.
[0037] FIG. 8 is a top view of the economizer 104 and further
illustrates how the heat recovery unit 106 is slidably inserted
into the economizer 104. FIG. 9 is a side view of the economizer
104 and further illustrates how the heat recovery unit 106
partitions the housing of the economizer 104 into an upper chamber
902 and a lower chamber 904. As described earlier in connection
with FIGS. 2A and 2B, the bypass damper assembly 108 (FIG. 1) is
controlled by a variable position actuator in the economizer 104,
where the actuator configures the bypass damper assembly 108 to
direct the exhaust flow in one of two exhaust flow configurations.
In a first exhaust flow configuration, the flue gases flow pass
over and through the heat recovery unit 106. Specifically, a
turbulent exhaust flow is created such that flue gases flow through
the lower chamber 904, through the heat recovery unit 106, and then
into the upper chamber 902.
[0038] In a second exhaust flow configuration, the flue gases flow
over and bypass the heat recovery unit 106. This configuration
prevents over-heating of the coils in case the liquid inside the
coils is not flowing or if the exhaust heat exceeds the performance
of the heat recovery unit 106. The combination of the variable
position actuator and the bypass damper assembly 108 allow
modulation of the exhaust air flow over the heat recovery unit 106
so that a variable percentage of the exhaust air can pass through
the heat recovery unit 106 and the remainder bypass the heat
recovery unit 106.
[0039] Reference is made to FIG. 10, which is a flowchart
illustrating an algorithm for controlling various components of the
mechanical draft system 102 of FIG. 1 for facilitating the flow of
flue gases according to various embodiments of the present
disclosure. For various embodiments, the following algorithm is
implemented in a mechanical draft system 102 with a damper assembly
108 (FIG. 1) on one end of the economizer 104 (FIG. 1) and a fixed
end plate 502 (FIG. 7) at the other end of the economizer 104.
Initially, when the mechanical draft system 102 is off, the damper
assembly 108 will be in an open position, and the inline draft
inducer 110 (FIG. 1) will be off. There will be no or at least very
limited flow of fluid through the finned tubes in the heat recovery
unit 106 (FIG. 1).
[0040] In block 1010, in response to a call for heat, the inline
draft inducer 110 begins operation and speeds up until a
predetermined draft set point in an external draft controller has
been reached. For some embodiments, the draft set point is
specified by the boiler manufacture. Specifically, the boiler
manufacturer publishes a draft range for the specific boiler, which
should be satisfied by the chimney/venting system. This set point
is then used as the draft set point.
[0041] In block 1020, once the draft set point has been reached,
the external draft controller releases the mechanical draft system
102 and allows the system to operate. In block 1030, an external
valve opens, and fluid will begin to flow through the heat recovery
unit 106. In block 1040, the actuator 301 will begin closing the
damper assembly 108 so that the hot products of combustion will
increasingly pass through the heat recovery unit 106. In block
1050, as the damper assembly 108 is closing and the products of
combustion is channeled through the heat recovery unit 106, the
inline draft inducer 110 will increase the fan speed in order to
overcome the additional pressure loss created by the air flow
through the heat recovery unit in order to maintain the
predetermined draft point.
[0042] In block 1060, with the hot products of combustion flowing
through the airside of the heat recovery unit 106, heat is
transferred through the finned tubes of the heat recovery unit 106
and eventually to the fluids flowing inside the tubes. In block
1070, if the fluid temperature increases to a predetermined
temperature (e.g., 200.degree. F.), the actuator 301 gradually
begins to open the damper assembly 108 to keep the temperature at
or below the predetermined temperature by allowing flue gases to
gradually bypass the heat recovery unit 106. Specifically, the
damper assembly 108 will go from a fully closed position to a half
open position and then to a fully open position.
[0043] In block 1080, if the fluid temperature reaches a second
predetermined temperature (e.g., 210.degree. F.), the actuator 301
completely opens the damper assembly 108 to allow the hot products
of combustion to completely by-pass the heat recovery unit 106 (as
shown in FIG. 2B) using "the path of least restriction" to prevent
the fluids from starting to boil.
[0044] In block 1090, when the mechanical draft system 102 begins
the process of turning off, the inline draft inducer 110 continues
to operate in a post-purge mode and the damper assembly 108 will
stay closed for a predetermined amount of time (e.g., 3 minutes),
thereby allowing the products of combustion to be cleared from the
heat recovery unit 106. In block 1100, after the post-purge period
passes, the actuator 301 will completely open the damper assembly
108.
[0045] Reference is made to FIGS. 11 and 12, which illustrate
different configurations in which the mechanical draft system 102
disclosed herein may be installed in a chimney system. In a first
configuration, the economizer 104 and the in-line draft inducer 110
are coupled together via mating bolt flanges 115 (FIG. 1), where
the mechanical draft system 102 is attached to a chimney in a
substantially horizontal orientation, as shown in FIG. 11A.
[0046] In FIG. 11B, the economizer 104 and the in-line draft
inducer 110 are coupled together via mating bolt flanges 115 (FIG.
1), where the mechanical draft system 102 is attached to a chimney
in a substantially vertical orientation. FIG. 12 illustrates
another configuration wherein the economizer 104 and the in-line
draft inducer 110 are separated from each other in the chimney
system. As shown, both the economizer 104 and the in-line draft
inducer 110 include a tapered inlet and a tapered outlet to
facilitate coupling to the ductwork.
[0047] It should be emphasized that the above-described embodiments
of the present disclosure are merely possible examples of
implementations set forth for a clear understanding of the
principles of the disclosure. Many variations and modifications may
be made to the above-described embodiment(s) without departing
substantially from the spirit and principles of the disclosure. All
such modifications and variations are intended to be included
herein within the scope of this disclosure and protected by the
following claims.
* * * * *