U.S. patent application number 10/909453 was filed with the patent office on 2005-12-01 for monitoring of flames using optical fibers and video camera vision system.
Invention is credited to Ganeshan, Ram.
Application Number | 20050266363 10/909453 |
Document ID | / |
Family ID | 35425742 |
Filed Date | 2005-12-01 |
United States Patent
Application |
20050266363 |
Kind Code |
A1 |
Ganeshan, Ram |
December 1, 2005 |
Monitoring of flames using optical fibers and video camera vision
system
Abstract
This invention relates to a flame detection method and
apparatus. More specifically, this invention relates to a flame d
on method and apparatus designed for simultaneously monitoring
several flames of different types such as pilot flames and main
flames of differing sizes and intensity. These detected flames can
be in one combustion unit or in several combustion units such as
industrial furnaces or ground flares. The underlying principle of
the invention is to collect and transmit light from each of the
flames by use of optical fibers and to insect the collected light
by a video camera vision system at the other end of the optical
fibers and to transmit the "live" images of the glows as well as
the "on/off" status of the burners to the control room, through
modern electronic communication techniques such as Ethernet and/or
wireless radio units.
Inventors: |
Ganeshan, Ram; (Sugar Land,
TX) |
Correspondence
Address: |
RAM GANESHAN
105 NORTH HALL DRIVE
SUGAR LAND
TX
77478
US
|
Family ID: |
35425742 |
Appl. No.: |
10/909453 |
Filed: |
August 2, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60520535 |
Nov 17, 2003 |
|
|
|
Current U.S.
Class: |
431/79 |
Current CPC
Class: |
F23N 2237/04 20200101;
F23N 2229/14 20200101; F23N 2229/20 20200101; F23N 2229/16
20200101; F23N 5/082 20130101 |
Class at
Publication: |
431/079 |
International
Class: |
F23N 005/08; F23N
001/00 |
Claims
What is claimed is:
1. A method for monitoring the status of a combustion unit having
at least one burner, comprising the steps of: (a) Installing an
optical fiber with tip its tip in or on the housing of the burner,
collecting the light from the flame of the burner on the tip of the
said optical fiber and transmitting said light to the tip of the
other end of the said optical fiber. (b) Acquiring a digital image
of the glow at the end of the tip of the said optical fiber
corresponding to the flame of the burner. (c) Calculating a value
for the relative intensity of the light in a frame defining an area
of the image corresponding to the flame of the burner (d) Comparing
the relative intensity value against a tolerance range for the
frame (e) Generating an alarm state output if the relative
intensity range is outside said tolerant range
2. The method of the claim 1 wherein the area of the frame is
substantially less than a total area of the image
3. The method of claim 1 wherein a series of digital images are
acquired at periodic time intervals and steps (c) through (e) are
repeated for each digital image
4. The method of claim 3 wherein the periodic time intervals are
regular and wherein each is less than one second.
5. The method of claim 1 further comprising of generating a display
of the digital Image
6. The method of claim 5 further comprising operatively coupling
said alarm state output with said display to superimpose an alarm
state display over said image in the display.
7. A method for monitoring the status of a combustion unit having
at least one burner with a main burner flame and a pilot burner
flame, comprising the steps of: (a) Installing two optical fibers
with their tips in or on the housing of the burner, one to collect
the light from the said main flame and the other to collect the
light from the said pilot flame and transmitting the said lights to
the other ends of the fibers for the digital imaging of the two
glows at the tips of the optical fibers. (b) Acquiring a digital
image of the two said glows corresponding to the main flame and the
pilot flame. (c) Calculating the values for the relative
intensities of the frames defining the areas of the images
corresponding to the two flames (d) Comparing the relative
intensity values against individual tolerance ranges for the two
frames (e) Generating an alarm state output if the relative light
intensity value for each and any of the flames is outside its said
tolerance range.
8. The method of claim 7 wherein a series of digital images are
acquired at periodic time intervals and steps (c) through (e) are
repeated for each digital image
9. The method of claim 8 wherein the periodic time intervals are
regular and wherein each is less than one, second.
10. A method for monitoring the status of a combustion unit having
a plurality of burners, comprising the steps of: (a) Installing
optical fibers in or on the housing of every burner so that the
tips of the fibers inside the burners view the flames of the said
burners and collecting the light from the flames of the burners and
transmitting the light to the other end of the fibers (b) Acquiring
a digital image of the glows at the far end of the tips of the
optical fibers. (c) Calculating the values for the relative
intensities of the frames defining the areas of the images
corresponding to the flames of the burners (d) Comparing the
relative intensity values against a tolerance range for each frame
(e) Generating an alarm state output if the relative light
intensity value is outside said tolerance range.
11. The method of claim 10 wherein a series of digital images are
acquired at periodic time intervals and steps (c) through (e) are
repeated for each digital image
12. The method of claim 11 wherein the periodic time intervals are
regular and wherein each is less than one second.
13. A method for providing additional safety by having more than
one fiber in each optical fiber bundle while monitoring the status
of flames in a combustion unit with one or more burners, comprising
the steps of: (a) Making special optical fiber cables with two
optical fibers in parallel inside every bundle. (b) Installing such
said special cables in or on the housing of every burner. (c)
Setting the parameter in the vision system to recognize
"two-distinct glows" inside the frame designated for each specific
flame. (d) Programming the vision software to display "flame on" or
"pass" if the image has at least one "glow" and to display "flame
off" or "fail" if both the glows are absent. (e) Generating an
alarm state output if the specific flame has no "glows"
14. A method for monitoring the status of several combustion units
each having one or more burners, comprising the steps of: (a)
Installing optical fibers in every burner in all the said
combustion units with their tips in or on the burners to view the
flames of the said burners and collecting the lights from the
flames on the tips of said optical fibers and transmitting the said
lights to the tips at the other end of the fibers (b) Acquiring
digital images of the glows at the tips of the optical fibers
corresponding to the flames of the burners (c) Arranging the lights
received in groups corresponding to each of the said combustion
units from which they originated (d) Calculating the values for the
relative intensities of the frames in each said group defining the
areas of the images corresponding to the flames of the burners (e)
Comparing the relative intensity values against a tolerance ranges
for each of the frames. (f) Generating an alarm state output if the
relative light intensity value is outside said tolerance range.
15. The method of claim 14 wherein a series of digital images are
acquired at periodic time intervals and steps (c) through (e) are
repeated for each digital image
16. The method of claim 15 wherein the periodic time intervals are
regular and wherein each is less than one second.
17. Apparatus for monitoring the status of one or more combustion
units having a plurality of burners, comprising: Optical fibers
with tips designed for easy installation in or on a burner housing
at the light-receiving end and into a dark chamber box at the
light-displaying end A dark chamber box: All the light displaying
ends of the said optical fibers will be installed on one end plate
of this enclosure impervious to external light. A machine vision
camera will be installed at the other end of the said box for
acquiring a digital image of the plurality of glows from the flames
corresponding to the burners. Special vision software on a
computer: The special software enables analyzing the specific flame
monitoring application and programming it into the camera system.
The program is thus customized for each application as per its
needs. The said programmed software is capable of (1) Calculating
an array of light intensity values relative to a baseline light
intensity value for a plurality of frames, each frame defining a
sub-area of the digital image corresponding to the flame for one of
the burners, (2) Comparing the relative intensity values against a
tolerance range for each frame, and (3) Generating an alarm state
output for each relative light intensity value that is outside the
range The data communication module: This module is capable of
receiving and transmitting through the Ethernet the video images,
the data of the on/off status of all the flames, other statistical
data such as history of the monitored data, and the time of flame
failure. An Ethernet cable to physically connect the above referred
communication module at the camera end to the below referred
gateway module at the control room end. A communications gateway
module that can receive and send video images and data from several
camera vision systems. One or more video monitors in the control
room to display the live images of the light glows from the flames
of the burners, the on/off status on all the burners, and other
statistical and-historical data on the performance status of the
burners. An alarm system activated by the alarm state output.
18. The apparatus of claim 17 for monitoring the status of one or
more combustion units having a plurality of burners, wherein: High
speed Ethernet wireless radio transmitters and receivers are used
instead of hard wire ethernet cable connection for communication
between the camera and the control room.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] U.S. Pat. No. 6,278,374 B1
[0002] USPTO's Number for the provisional application of this
patent: 6052 0535
[0003] Provisional Application filing date: Nov. 17, 2003
FEDERALLY SPONSORED RESEARCH
[0004] Not applicable
SEQUENCE LISTING OF PROGRAM
[0005] not applicable
BACKGROUND OF THE INVENTION
[0006] Heaters, boilers, furnaces, flares, ovens, incinerators,
driers, heated baths and other combustion equipment have single or
multiple burners. The term furnace will be used in all of the text
below to cover all the combustion units mentioned above. Some large
heat capacity burners, both gas and oil fired, modulated and fixed
capacity, are fitted with smaller heat capacity pilot burners. In
many cases both Pilot and the Main flames are continuously
monitored for the safety of the furnace.
[0007] Well-known flame detection methods are Ultra Violet
scanners, thermocouples and flame rods. The currently available
flame detection technologies have several disadvantages. These are
listed here.
[0008] Ultra Violet (UV) Scanners
[0009] These provide flame control signals, depending on the
intensity of illumination detected, which varies directly with the
electrical current generated. They fail frequently if the flame
intensity or composition of the fuel fluctuates and/or dust settles
on the viewing glass of the scanner. Also the generated current is
very small in magnitude, in the order of micro-amps. UV scanners
are effective only with certain fuels whose combustion results in a
flame with a lot of UV component in it. This is a big limitation.
Oil fired burners, which make a good percentage of burners in the
world, cannot use them. In addition, the sensitivity of the UV
scanners reduces with shelf life and the operating life. Frequent
replacements are necessary.
[0010] The UV scanning technique also presents great difficulty
when desired to monitor pilot flames. Due to the small size of the
pilots and their inaccessible locations, great difficulties are
encountered in finding a suitable location for the scanner.
[0011] Flame Rods
[0012] Flame rods work on the ionization principle. The sensing end
of the flame rod is actually placed within the body of the flame.
But continued exposure to flame and high temperatures leads to
thermal degradation leading to extremely short lifespan, typically
a few months. Replacement and even maintenance are difficult since
the sensor locations and the insulated mounting arrangements are
difficult to access. Also the furnace has to be shut down for
inspection and repair. Such shutdowns result in high operating
costs for the facility.
[0013] Thermocouples
[0014] Thermocouples fail after sometime due to their close
proximity to the flame and pose similar difficulties as Flame Rods
to access and higher costs.
[0015] All the abovementioned flame sensors have the common
disadvantage of requiring multiple sensors for multiple burners,
since these sensors are capable of monitoring only one flame at a
time.
[0016] Video Camera Technology
[0017] In order to overcome the abovementioned disadvantages, the
author of this invention patented (see U.S. Pat. No. 6,278,374 B1)
a technology that uses a video camera in combination with vision
software to monitor the status of a multiple flames within one
furnace unit. Also with that technology multiple burners can be
monitored simultaneously and on a continuous basis. The camera is
set up directly on the furnace to view the flames through a view
glass mounted on the furnace.
[0018] However that technology has the following disadvantages:
[0019] One disadvantage of this method is the unavailability in
practice of such view glasses in desirable locations. A large
number of existing furnaces do not have sight ports where the
camera can be mounted to view the flames. Often existing or planned
sight ports are not ideally located to view all the burners. That
makes the method difficult to apply especially since installation
of a new sight port can be done only when the furnace is shut down.
Often a suitable maintenance shut down is typically scheduled in
intervals of several years. This difficulty results in continued
reliance on less reliable UV detection methods for flame monitoring
and control, raising safety concerns.
[0020] Even when such maintenance shut down is scheduled, mounting
of the camera in a suitable location requires extensive advance
planning and significant additional costs in the necessary
extension of the shut down period (leading to charges for lost
production), as well as in the costs of the modification itself.
The modification involves, at a minimum, steel work, refractory
patch up work and scaffolding inside the furnace etc. Also since
the cameras have to be located on top of the furnace in some cases,
ladders and platforms to access the sight port have to be provided.
They add to the cost in addition to a lot of engineering and
planning.
[0021] The camera has to be installed on the heater, and safety
considerations in facilities such as petroleum refineries, chemical
plants etc dictate that the camera and its accessories have to be
in explosion proof housing. This also increases the system cost
considerably.
[0022] Proposed Optical Fiber Technology
[0023] In contrast, the present invention allows the optical fiber
ends to be installed in or on the burner housings by drilling and
tapping the burner casing plate while the heater is in operation
rather than be dependent upon or wait for the installation of a
view port for mounting the camera.
[0024] Additionally, in many cases, the field of the camera does
not permit the entire range of burners to be viewed comprehensively
and allows viewing only a few burners well. This necessitates
installing multiple cameras on multiple sight ports on the same
furnace. This will increase the cost and make the controls more
complicated. The proposed invention solves that problem; one camera
can view all the optical fiber glows from all the burners
simultaneously.
[0025] Another disadvantage of the before mentioned patent is that
in many furnaces, such as industrial boilers, code regulations
require both the pilot flame and the main flame of all burners to
be monitored directly. A camera directly viewing the flames may
find it difficult to distinguish the presence of small pilot behind
larger main flame envelopes. The present invention can view the
glows from the pilot and the main flame individually and
simultaneously.
[0026] The principal advantage and a major breakthrough in the
monitoring technology due to the present invention of using fiber
optics is the extension of one camera's capability to monitor
several burners in several combustion units simultaneously. This
totally eliminates the use of dedicated camera for each and every
combustion unit separately as required by the author's previous
patent.
[0027] There exists, therefore, a need for a flame detection method
and apparatus that can utilize a single apparatus to concurrently
monitor and detect failure in one or more burners in one or more
combustion units.
SUMMARY
[0028] The present invention relates to a new technology in the
furnace flame detection, both in principle and in the choice of
detection equipments. Optical fibers are used to collect the light
from several flames from the burners at the furnace end and
transmit the light through a desired distance to a video camera
box, which is protected from external light sources and located in
a safe area and convenient place. Thus the operator at the control
center can conveniently and continuously view the "live" images of
the glows and the status data on the burners.
[0029] The uniqueness of this invention lies in the fact
[0030] That the sensor can be inserted while the furnace is in
operation
[0031] That the video camera is independent from the furnace
[0032] That it can be at a distance from the furnace
[0033] That it can be at a location convenient to the furnace
owner
[0034] That it can reliably and accurately sense small variations
in the intensity of the flame as evidenced by the intensity of
illumination, and
[0035] That it is a video camera that is set up to view the glows
at the tips of the optical fibers and not a UV scanner as in some
applications of the commercially available UV technology.
[0036] That a large number of burners from numerous different
combustion units can be monitored by a single camera vision
system.
BRIEF DESCRIPTION OF THE TECHNOLOGY
[0037] The technology to monitor flames using optical fibers and
the video camera using commercially available software will be
described here briefly. The light energy received from the flames
and transmitted to the far end tips of the fibers is viewed as
"glows" (the glows will look like "full moons") by the video
camera. The image of the glow from each of the flames is framed
inside an envelope termed as a region of interest on the monitor
screen. The vision software in the solid-state processor of the
camera system determines the presence or absence of the flame using
a few parameters. The first parameter looks for an object inside
the frame. This is a case of "presence or absence" determination;
"the presence of glow" confirms the presence of flame. The second
parameter is based on "the intensity of the glow". If the glow is
bright, the flame is strong. If it is dim, the flame is weak. The
software can distinguish hundreds of gradations within the range
between very dim and very bright.
[0038] The "presence of glow" and the "intensity of glow" are two
independent parameters in the flame analysis and decision making
process. Commercially available softwares have many other
parameters available to analyze the flame. The inspection results
as well as the live video images of the glows are transmitted to
the remotely located control room through modern communication
methods such as hard wired Ethernet cables and/or wireless radios.
The video camera views only the light brought to it by the optical
fibers from the burner flames. This feature brings with it a lot of
advantages and opens up a lot of application possibilities in the
industry; these will be elaborated in the text below.
DETAILS OF THE INVENTION
[0039] The light-receiving end of the optical fiber is located at
an ideal place in or on the burner housing to view the flame; the
tip of the fiber is usually inside a cool air stream. Dust will not
collect on the sensing head since there is a constant flow of air
across it. The fiber could be made of glass or silicon quartz
material, which can withstand high temperatures normally
encountered in the furnace. Stainless steel tube sheathing protects
the fiber on the sides. Such optical fiber cables are commercially
available.
[0040] The flame detection system has several self-checking
features.
[0041] 1. The fiber bundle inside the cable can have one or more
individual fibers. They display individual glows at the other end.
When two fibers are used, it will display two distinct dots of
glows within the circle at the other end. If one fiber should
develop a defect, for example due to a break in the fiber due to
long usage, the other fiber will be proving that the flame is
on.
[0042] 2. The camera views several tips simultaneously. The
camera's functionality is confirmed as long as the monitor displays
some glows from the fiber tips.
[0043] An Ethernet cable transmits the video signals of the glows
as well as the on/off data to a wireless radio transmitter near the
camera. A wireless radio receiver at the control room end far away
from the furnace receives such video signals and the on/off data
and transmits them to the video monitor screen and to the computers
(programmed logic controllers, commonly termed PLC, or the
Distributive Control System, commonly termed DCS). The PLC and the
DCS take further control action on the burners and/or the furnace.
The vision software system, the PLC and the DCS have the capability
to communicate with each other through the digital I/O inputs and
outputs of the system. Alternatively, the video signals and the
inspection data can be transmitted using hard cable connection,
instead of the "wireless radio", to the monitor through a
communication link module.
[0044] Digital data communication devices and wireless high-speed
radio transmitters and receivers are commercially available.
[0045] One has the option to select the appropriate vision
software, the communication devices, the wireless radios etc from a
large number of suppliers.
[0046] This invention has several major advantages over the
presently commercially available technologies.
[0047] The optical fibers bring the light to the camera. So the
camera can be at a convenient location e.g., control room, at a
distance and away from the flames. One need not look for a suitable
location on the heater for the camera.
[0048] Since each glow is a small circle (say 1/8.sup.th inch
diameter) several burners (or glows) can be simultaneously
monitored with one camera.
[0049] One camera system can literally monitor hundreds of burners
simultaneously. The ramifications of this statement are enormous.
It is conceivable to monitor several different heaters with
numerous burners in each one of them to be monitored by one system.
None of the present technologies can do that. This is a very
substantial step forward in flame and furnace monitoring
technology.
[0050] The economic advantages of this step will be large. It is
conceivable that an entire plant with tens of furnaces having
hundreds of burners can be monitored with one video camera system.
If the plant should desire redundancy for the sake of additional
safety a second system can be added costing only a minor fraction
of the investment for a similar protection with the present
technologies.
[0051] Another big advantage of this invention is that each burner
can be fitted with 2 optical fiber heads, for a small cost
addition, for back up and for redundancy. The second set of fibers
from all the burners can be viewed by a duplicate camera system and
give the plant additional margin of safety.
[0052] Another distinct advantage of this invention is that the
operator can see on the control room monitor the "live" images of
the glows and the status data on the burners.
[0053] Another major and very practical advantage of this system
over the patented video camera flame scanner system (U.S. Pat. No.
6,278,374 B1) is that the optical fiber ends can be installed in or
on the burner housing by drilling and tapping the burner bottom
plate while the heater is in operation whereas the other system is
dependent upon installing a view port for mounting the camera. This
is not possible while the heater is in operation, because of the
size of the view-ports (usually 4 inches pipe-size) necessary and
the safety issues involved.
Embodiments of the Invention
[0054] A preferred embodiment of the present invention provides a
method for monitoring the status of a combustion unit having at
least one burner. An optical fiber (OF in short) is installed in or
on the housing of the burner to receive the light from the flame.
The flame could belong to the main burner or the pilot burner. OF
transmits the light through the long length of a sheathed cable to
its other open end. This far end is inserted into a dark box so
that the camera can focus on the glow at its tip. The glow at the
tip of the OF will look like a full moon. A digital image of this
is acquired by the video camera. The vision software can use any of
the various parameters available to determine the presence or
absence of the flame based on the glow and its intensity. It can
define total absence of a glow as flame failure or a very weak glow
(based on the intensity parameter) as a flame failure. An alarm
state output is generated to inform the furnace operator of the
flame failure. The monitor in the control room will show the video
image of the glows as well as the inspection results.
[0055] Another preferred embodiment of the present invention
provides a method for monitoring the status of a main flame and a
pilot flame in a combustion unit having at least one burner. Two
optical fibers are located in the burner, one to sense the light
from the main flame and the other to sense the light from the
smaller pilot flame. The two far ends of the OF cables are inserted
into the dark chamber. A digital image of the two "full moons" is
acquired by the video camera. The decision making process to
declare a flame failure is the same as described in the first
embodiment above.
[0056] Yet another preferred embodiment of the present invention
provides a method for monitoring the status of flames in a
combustion unit having several burners. Optical fibers are run from
all the burners, (from both the main flame and the pilot flame of
each burner if so required), to the dark chamber. A digital image
of all the "full moons" is acquired by the video camera. The
decision making process to declare a flame failure is the same as
described in the first embodiment above.
[0057] Yet another preferred embodiment of the present invention
provides a method for monitoring the status of flames of a
plurality of burners from several independently operated combustion
units. Optical fibers are run from all the burners of the different
said combustion units, (from both the main flame and the pilot
flame of each burner if so required), to the dark chamber. A
digital image of all the "full moons" is acquired by the video
camera. The decision making process to declare a flame failure is
the same as described in the first embodiment above. The monitor
screen can have split sections to show the furnaces as separate
entities on the screen; monitoring results on flames belonging to
each furnace can thus be seen separately. Such split screen vision
technology is readily available.
[0058] Yet another embodiment of this invention provides for a
complete system to monitor the status of several flames, main
and/or pilot. The optical fibers installed in or on the burners
bring the light to the dark chamber. The camera vision system
inspects the images. The results of the inspection are communicated
through a physically routed Ethernet cable, if necessary over a few
hundred feet to another communication module in the control room.
This latter module sends the video images and the results to the
monitor. It can also send the data to the PLC and/or the DCS for
them to take further logical actions.
[0059] Yet another preferred embodiment of the invention provides
an apparatus for monitoring the status of a combustion unit or
combustion units having a plurality of burners. The apparatus
consists of optical fiber cables, a collection box for the far end
of the tips of the cables, a digital camera system that has an
embedded vision software, a communication module with Ethernet
technology, wireless high speed Ethernet radio transmitter and
receiver, a video monitor in the control room and digital I/O input
output boards, PLC and/or DCS. The optical fibers bring the light
of the flames to the dark chamber. The camera views the images. The
embedded vision software determines the intensity values and
compares them against the tolerance ranges. The inspection results
and the video images are sent through the communication module to
the radio transmitter. The radio receiver at the other end sends
the live video images and the on/off data to a module, which is a
communication gateway. This module sends the data to the monitor
screen, to the PLC and or the DCS. The monitor screen displays the
live images of the "full moons" indicating which of the burners are
on and which are off.
[0060] Other features and advantages, of the present invention will
be made clear to those skilled in the art by the following detailed
description of the preferred embodiments constructed in accordance
with the teachings of the present invention.
DRAWINGS--FIGURES
[0061] Closely related figures in the drawings have the same number
but different alphabetic suffixes.
[0062] FIG. 1 shows the furnace and its components.
[0063] FIG. 2 shows the plan view of the burners in the
furnace.
[0064] FIG. 3A shows a burner having the main flame without a pilot
flame. Some industrial burners do not have pilots. The optical
fiber 6 is installed to view the main burner.
[0065] FIG. 3B shows a burner having a main flame and a pilot
flame. Optical fibers are installed to view the main flame and the
pilot flame.
[0066] FIG. 3C shows two independent optical fibers to view each
flame.
[0067] FIG. 4 shows the monitoring of flames from two different
furnaces.
[0068] FIG. 5 shows the application of the invention to the main
burner flame. Note that the far ends of the optical fibers are
installed into the dark enclosure numbered as 10. To avoid crowding
of the sketch, only one burner is shown. The Camera 11 passes the
images to the communication module 12. Module 12 is connected to
the Ethernet wireless radio transmitter 13.
[0069] FIG. 6 shows the application of the invention to the pilot
flame of the burner. Note that optical fiber cable leads connect
each burner to the enclosure numbered as 10. To avoid crowding of
the sketch, only one pilot burner is shown. Items 11, 12 and 13 are
same as in FIG. 5
[0070] FIG. 7 shows the cut sectional view of the enclosure
numbered as 10. The combustion unit, in this example, has 4
burners.
[0071] FIG. 8 shows both the main burner flame and the pilot flame
being monitored by the invention system.
[0072] FIG. 9 shows a cut sectional elevation of the dark enclosure
numbered as 10. Note that there are 8 optical fiber heads, four for
the four main flames and four for the four pilot flames.
[0073] FIG. 10 shows the radio receiver 14 connected to the data
link module which sends the images of the glows and the pass/fail
information to the video monitor 16, to the PLC 21 (Programmable
Logic Controller) and/or to the DCS (Distributive Control System)
22.
[0074] FIG. 11 shows a complete system without the use of wireless
radios. The camera side communication module 12 is directly
connected to the monitor side communication module with an Ethernet
cable 23. This cable could be a few hundred feet long.
[0075] FIG. 12 shows a complete system using wireless radios
instead of hard wire Ethernet cable connection.
REFERENCE NUMERALS IN THE DRAWINGS
[0076] FIGS. 1 to 12
[0077] 1. Furnace
[0078] 2. Flame
[0079] 3. Burner body
[0080] 4. Main burner
[0081] 5. Pilot burner
[0082] 6. Optical fiber head at burner end
[0083] 7. Pilot flame
[0084] 8. Optical fiber cable
[0085] 9. Optical fiber head at camera end
[0086] 10. Dark Chamber Receptacle box for optical heads
[0087] 11. Video Camera with embedded vision software
[0088] 12. Communication module
[0089] 13. High speed Ethernet wireless radio transmitter
[0090] 14. High speed Ethernet wireless radio receiver
[0091] 15. Data link module
[0092] 16. Video monitor in the control room
[0093] 17. Live video images of the light glows from the flames
[0094] 18. Burner designation for result reporting
[0095] 19. Flame "on/off" inspection report
[0096] 20. Other statistical data such as time of failure etc
[0097] 21. Programmable Logic Controller
[0098] 22. Distributive control system
[0099] 23. Ethernet cable between the camera end and the control
room.
DETAILED DESCRIPTION: FIGS. 1 TO 12
[0100] The camera vision system for monitoring the status of the
flames in furnaces using optical fibers is illustrated in the FIGS.
1 to 12.
[0101] The purpose of the figures is to illustrate the invention.
The actual number of elements (example: number of burners, number
of optical fiber cables etc) will vary from case to case in
industrial applications. The furnace illustrated in the example has
4 burners. The furnace 1 has four burners.
[0102] Several different applications of flame monitoring are
described.
[0103] FIG. 4 shows simultaneous monitoring of the flames from
several furnaces
[0104] FIG. 5 shows monitoring of the main flame only.
[0105] FIG. 6 shows monitoring the pilot flame only.
[0106] FIGS. 8 and 9 show monitoring of both the main flame and the
pilot flame of several burners in the same furnace.
[0107] FIGS. 5,7 and 10:
[0108] Main Flame Monitoring:
[0109] Optical fiber ends 6 installed in or on the steel housings
of the burners receive light from the main flames 2 and transmit it
through the optical cables 8. The glow emitting ends of the optical
fibers 9 are installed on one end of a dark enclosure 10. FIG. 7
shows a cut section of the dark enclosure box showing the installed
optical fiber heads 9. The video camera vision system 11 views the
light glowing at the inside tips of 9. The software in the
processor of the vision system inspects the images and communicates
the "on/off" status as well as the live video images through the
communication gateway module 12 through the wireless high speed
Ethernet radio transmitter 13.
[0110] The radio receiver 14, the communication module 15, the
video monitor 16, the PLC (Programmable Logic Controller) 21 and/or
the DCS (Distributive Control System) 22 are in the control room at
a location far away from the furnace 1.
[0111] Information received by 14 is sent to the module 15. It
sends the data to a video monitor 16 in the control room. The
operator can see the "live" images of the "light glows" 17 and the
"on/off" data 18 and 19 on the screen. 18 lists the burners. 19
shows the inspection results.
[0112] FIG. 6:
[0113] Pilot Flame Monitoring
[0114] The technology is the same as in the case of main flame
monitoring except that the light receiving optical heads are placed
in or on the steel housing of the pilots. There are industrial
burner applications in which only the pilot flames are monitored.
This invention is applicable in such cases.
[0115] FIGS. 8 and 9:
[0116] Monitoring of the Main Flame and the Pilot Flame of the Same
Burner
[0117] The inspection method of this invention is applied to both
the main flame and the pilot flame of each burner. So the video
camera will be looking at 4 optical heads for the 4 main flames (in
this example illustration) and 4 optical heads for the 4 pilot
flames. This is shown in FIG. 9.
[0118] FIG. 11:
[0119] Complete System with Hard Wired Ethernet Cable 23 Between
Camera End and Control Room End.
[0120] This figure shows a complete system wherein the optical
fibers bring the light of the burners as glows to be inspected by
the camera. The communication between the module 12 at the camera
end and the module 15 at the control room end is through a hard
wired Ethernet cable 23. All other details are similar to the
description for the other figures listed above.
[0121] FIG. 12:
[0122] Complete System with Radio Transmitter and Receiver
[0123] This figure shows a complete system wherein the
communication between the camera end and the control room end are
through high speed Ethernet wireless radios. The radios replace the
hard wire 23.
* * * * *