IRIS S550 Applications Manual Download Page 7

The cable wiring on the other end going to the
signal processor is easier to do. The cable should
be prepared in a similar way to the plug end
particu larly the shield from the WHT wire. Make
sure the shield doesn't touch the other terminals.

SIGHT ING OF VIEW ING HEAD

The sighting of the viewing head should be
parallel to the cen terline of the burner in the
direction of the flame. The sight pipe should be
mounted as close to the cen terline as possible; the
idea is to sight along the flame rather than across
the flame. This will help prevent drop outs of the
flame under changing load condi tions.

Utilizing a sighting or the sight pipe aimed at the
root of the flame (where the turbulent combustion
air mixes with the flame) is a good starting point
for optimizing the sighting. Using a swivel mount
to “zero-in” on the highest signal will assure
maximum performance. Make sure the diameter
of this sight pipe is large enough to allow a
reasonable field of view. The S550’s has two
angles of view, one for the IR detector, which is
1.0

° 

and one for the UV detector which is about

3.0

°; 

 this trans lates into a circle of view that

varies with the viewing distance as shown in the
following table.

Dis tance Dis tance

Di ame ter of

IR view

Di ame ter of

UV view

ft

inches

inches

inches

2

24

.64

1.3

3

36

.73

1.9

6

72

1.45

3.8

12

144

2.90

7.6

18

216

4.35

11.4

Detecting flame in a sulfur recovery unit can
present problems for flicker type flame monitors
such as the IR detector in the S550 viewing head.
The IR detector will detect natural gas used for the 
warm-up of the reactor. Usually the combustion
air is turbulent enough to cause a good flicker

signal. When the sour gas is intro duced and the
natural gas shut down the flame signal may drop
off or drop out entirely. The reason for this is that
there is a complete change in the flicker content
for the existing viewing head sighting. If this is the 
case, then one should try and optimize the flame
signal for the sour gas by “zeroing-in” on this
flame, not the warm-up burner.

After optimizing the sighting for the sour gas one
may find that the signal level is too low on the
natural gas. One should then try the UV detector
for this appli cation. It may be necessary to use two 
sets of set points for flame ON and flame OFF, one 
set for proving and detecting the natural gas flame
and the other for proving and detecting the sour
gas flame. The switch-over from Channel A to
Channel B should be done when removing the
natural gas burner. This can be imple mented from
the burner control system. This switch-over and
the use of Channels A and B with their
independent settings is explained in the section

ASSIGNING DIFFERENT S550 SETTINGS TO
CHANNEL A and B

 on page 9.

IR DETECTOR

The IR detector responds to the flicker content in
the flame. Flame flicker is caused by the
combustion, or forced air injected into the flame.
This combustion air can be mixed with the fuel
(pulverized coal) or can be intro duced separately.
In either case, forced air at high velocity is intro 

-

duced in such a way as to aid the combustion
process. This air is usually made turbulent by
causing it to swirl with spin vanes located in the
burner barrel.

Flame flicker is created when this turbulent air
mixes with the flame. It is composed of random
frequencies from zero Hz to over 2,000 Hz. The
amount of high frequency flicker (above 200 Hz)
is dependent on the fuel and burner. The amplitude 
of the flicker frequencies always follows an
exponential curve with zero frequency having the
highest amplitude and the higher frequencies the
lowest. The amplitude level of the higher
frequencies is usually 40dB down (factor of 100)
from zero Hz or DC.

PAGE 7

IRIS MODEL S550 APPLICATION MANUAL

Summary of Contents for S550

Page 1: ...PAGE 1 IRIS MODEL S550 APPLICATION MANUAL FLAME MONITORING SYSTEM MODEL S550 S552 S556 VIEWING HEAD APPLICATION MANUAL ...

Page 2: ... ARE STORED 8 ASSIGNING DIFF S550 SETTINGS TO A B 9 USING TWO VIEWING HEADS PER AMPLIFIER 9 BEFORE MAKING ADJUSTMENTS 10 NEW P520 P522 FRONT PANEL 10 CALIBRATING THE S550 10 EXAMINING RESULTS GAIN SETTINGS CALIB 10 CHECKING OR CHANGING UV GAIN 11 CHECKING OR CHANGING IR FILTER 11 CHECKING OR CHANGING IR GAIN 11 MANUAL SETUP OF THE S550 12 RETURN TO DEFAULT SETTINGS 12 ANGLE OF VIEW 13 GENERAL COMM...

Page 3: ...Filter Selection 1 8 b IR gain 0 699 When it comes to features like CAL which will be described later the operator is only given those choices which are appropriate For example he does not have to choose between calibrating with the UV sensor or the IR sensor in CAL he is only offered the choice of calibrating with the IR sensor or not This is shown in the FLOWCHART OF S552 PROGRAMMING Figure 4 on...

Page 4: ...processors Also the earlier IR sensitive family members had only 4 high pass filters to choose from the S550 has 8 S511 S512 S550 LL 36 Hz 1 16 Hz L 71 Hz 2 24 Hz M 105 Hz 3 33 Hz H 186 Hz 4 52 Hz 5 75 Hz 6 100 Hz 7 155 Hz 8 215 Hz TECHNOLOGY USED IN THE S550 The UV and IR sensors in the S550 share a common optical axis efficiently by using a unique dichroic beamsplitting mirror Over 80 of the ult...

Page 5: ...PAGE 5 IRIS MODEL S550 APPLICATION MANUAL ...

Page 6: ...e done as follows Remove the plug from its packaging and layout the components 1 Strip 2 inches of the cable outer cover from the cable removing any cellophane wrap or filler material and strip the insulation from the shielded wire if insulated over shield a full 2 inches to expose shield 2 Slide the shield back until a bulge develops close to where the wire exits the cable outer covering 3 Carefu...

Page 7: ... entirely The reason for this is that there is a complete change in the flicker content for the existing viewing head sighting If this is the case then one should try and optimize the flame signal for the sour gas by zeroing in on this flame not the warm up burner After optimizing the sighting for the sour gas one may find that the signal level is too low on the natural gas One should then try the...

Page 8: ...ition the zone of higher UV intensity does not overlap the same zones of adjacent or opposing burners so that with proper sighting discrimination is predictable As a general rule the sighting of the S550 when using the UV detector will be more likely a line of sight than the IR flicker detector which will read flame signals bouncing off the side of the sight pipe and other reflectors Sometimes the...

Page 9: ...n the signal level so if the associated S550 and signal processor has been previously calibrated it will be necessary to calibrate the processor again so that the gain settings will be correct If the discrimi nation is still not satisfactory then try an orificing disc with a smaller diameter hole Generally speaking orificing should always be considered when the burner s are large 50K lbs of steam ...

Page 10: ...manually changing S550 settings when the desired channel is not selected press the push button for the desired channel and then proceed During the process of examining or changing the S550 settings with the Channel A and B NO and YES push buttons the red LED for the channel which the changes apply will be blinking One should visually check which channel push button is lighted when the S550 setting...

Page 11: ...ture one does not have the option of working with the channel that is not selected by the external input 3 Bring the firing rate of the burner to a low fire condition 4 If the flame relay has not pulled in adjust the flame on off set points so it does pull in 5 Decide whether to calibrate using the UV or IR sensor See earlier sections on I R DETECTOR and UV DETECTOR At the front panel of the P520 ...

Page 12: ...r all of the initial setup proce dures described in this manual Further infor mation on how these filters can affect the discrimi nation ratio is found in the P520 APPLICATION MANUAL and in the P522 APPLICATION MANUAL in the section MULTIBURNER REQUIREMENTS For further information please call the factory or contact IRIS Systems Inc See page 13 for contact information CHECKING OR CHANGING IR GAIN Y...

Page 13: ...tinue reducing the gain in steps of 100 until the displayed reading is reduced Then set the gain so the reading is in the 1000 to 1400 range If the IR sensor was not saturated one can skip paragraph 5 below 5 If the S550 was saturating one should check the aiming of the S550 again using the LED on the back of the housing to adjust the viewing angle of the head for a maximum pulse rate If the LED p...

Page 14: ...vative product that this is the ultimate state of the art flame monitor The way it works has been described only in a general sense and obviously the algorithms implemented by the embedded controller software are proprietary and will not be made public Any existing P520 or P522 signal processor can be upgraded to an S550 compatible processor by changing the controller chip and the front panel TECH...

Page 15: ...PAGE 15 IRIS MODEL S550 APPLICATION MANUAL Figure 1 Figure 2 ...

Page 16: ...IRIS MODEL S550 APPLICATION MANUAL PAGE 16 Figure 3 ...

Page 17: ...PAGE 17 IRIS MODEL S550 APPLICATION MANUAL Figure 4 ...

Page 18: ...PAGE 18 IRIS MODEL S550 APPLICATION MANUAL Figure 5 ...

Page 19: ...PAGE 19 IRIS MODEL S550 APPLICATION MANUAL 5 June 1997 ...

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