Teledyne 9700 User Manual

Flue Gas Analysis System
Model 9700Model 9700
Model 9700
Model 9700Model 9700
Flue Gas Analysis
SystemSystem
System
SystemSystem
InstrInstr
Instr
InstrInstr
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uction Manual
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TELEDYNE BROWN ENGINEERING
Analytical Instruments
P/N M48985
10/27/94
i
Model 9700
Copyright © 1994 Teledyne Brown Engineering Analytical Instruments
All Rights Reserved. No part of this manual may be reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any other language or com­puter language in whole or in part, in any form or by any means, whether it be electronic, mechanical, magnetic, optical, manual, or otherwise, without the prior written consent of Teledyne Analytical Instruments, 16830 Chestnut Street, City of Industry, CA 917491580.
Warranty
This equipment is sold subject to the mutual agreement that it is warranted by us free from defects of material and of construction, and that our liability shall be limited to replacing or repairing at our factory (without charge, except for transportation), or at customer plant at our option, any material or construction in which defects become apparent within one year from the date of sale, except in cases where quotations or acknowledgements provide for a shorter period. Components manufactured by others bear the warranty of their manufacturer. This warranty does not cover defects caused by wear, accident, misuse, or neglect. We assume no liability for direct or indirect damages of any kind and the purchaser by the acceptance of the equipment will assume all liability for any damage which may result from its use or misuse.
We reserve the right to employ any suitable material in the manufacture of our apparatus, and to make any alterations in the dimensions, shape or weight of any parts, in so far as such alterations do not adversely affect our warranty.
Important Notice
This instrument is intended to be used as a tool to gather valuable data. The information provided by the instrument may assist the user in eliminating potential hazards caused by the process that the instrument is intended to monitor; however, it is
essential that all personnel involved in the use of the instrument or its interface with the process being measured be properly trained in the process itself, as well as all instrumentation related to it.
The safety of personnel is ultimately the responsibility of those who control process conditions. While this instrument may be able to provide early warning of imminent danger, it has no control over process conditions, and can be misused. In particular, any alarm or control system installed must be tested and understood, both as to how they operate and as to how they can be defeated. Any safeguards required such as locks, labels, or redundancy must be provided by the user or specifically requested of Teledyne when the order is placed.
The purchaser must be aware of the hazardous conditions inherent in the process(es) he uses. He is responsible for training his personnel, for providing hazard warning methods and instrumentation per the appropriate standards, and for ensuring that hazard warning devices and instrumentation are maintained and operated properly.
TBE/AI, the manufacturer of this instrument, cannot accept responsibility for conditions beyond its knowledge and control. No statement expressed or implied by
this document or any information disseminated by the manufacturer or his agents is to be construed as a warranty of adequate safety control under the user’s process conditions.
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TELEDYNE BROWN ENGINEERING
Analytical Instruments
Flue Gas Analysis System
Table of Contents
1 Introduction
1.1 General..............................................................................1
1.2 Sample Conditioning..........................................................2
1.3 Oxygen Analyzer Section..................................................4
1.3.1 Standard Features .............................................. 1-4
1.3.2 Optional Features ...................................................7
1.4 Combustible Gas Analyzer Section....................................9
1.4.1 Operating Controls and Indicators ........................12
1.4.2 Recessed Secondary Controls..............................13
1.4.3 Meter Trim.............................................................13
1.4.4 Analog Output .......................................................13
2 Theory of Operation
2.1 Oxygen Analyzer................................................................1
2.2 Combustible Analyzer .......................................................3
2.3 Detector ............................................................................4
3 Installation
3.1 Electrical Connections .......................................................1
3.1.1 Power......................................................................1
3.1.2 Output Signal Voltage .............................................1
3.1.3 Alarm and/or Control Circuitry.................................3
3.1.4 Output Signal Current .............................................3
4 Operation
4.1 Startup of Oxygen Analyzer ...............................................1
4.1.1 Preliminary ..............................................................1
4.1.2 Meter Zeroing ..........................................................1
4.1.4 Initial Calibration and Equilibration..........................2
4.1.5 Operational Calibration ...........................................4
4.1.6 Routine Operational Calibration..............................5
4.2 Startup of Combustibles Analyzer......................................5
4.2.1 Procedure ...............................................................5
4.2.2 Span Gas ................................................................7
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Model 9700
4. 3 System Startup ..................................................................7
4.3.1 Analyzer Startup .....................................................7
4.3.2 Sample System Startup ..........................................7
5 Maintenance & Troubleshooting
5.1 Maintenance ......................................................................1
5.1.1 Routine Maintenance ..............................................1
5.1.2 Oxygen Cell Replacement ......................................1
5.1.3 Cell Warranty ..........................................................2
5.1.4 Spray Nozzle...........................................................3
5.1.5 Water Strainer .........................................................3
5.1.6 Filter Condensate Trap ...........................................3
5.1.7 Combustible Sensor................................................3
5.1.8 Pump.......................................................................4
5.2 Troubleshooting .................................................................4
5.2.1 General ...................................................................4
5.2.2 Oxygen Analyzer Section.....................................5
5.2.2.1 Inability to Calibrate ...................................5
5.2.3 Combustible Analyzer Section ................................6
5.2.3.1 Inability to Calibrate ...................................6
5.2.3.2 No Alarm With High Gas Level ..................7
5.2.3.3 Lamp Failure ..............................................8
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Appendix
Specifications.............................................................................1
Recommended Spare Parts List................................................3
Reference Drawings ..................................................................4
Response of Combustible Sensor to Various Gases .................5
Supporting Equipment for Flue Gas Analysis Systems..............7
General Maintenance for CC-2B Series Pumps ........................9
Maintenance ......................................................................9
Repair ................................................................................9
Supplementary Instructions for Servicing the CC-60B Flex-I-
Liner Pump ..............................................................................13
Replacing the Liner in the Flex-I-Liner Pump ..................14
TELEDYNE BROWN ENGINEERING
Analytical Instruments
Flue Gas Analysis System General Information
Introduction
1 Overview
The Model 9700 analyzer system (see Figure 1) is an integrally housed combination of analyzers designed to continuously monitor the two primary components of flue gas which are the best indicators of combus­tion efficiency and safe operation. Through use of volumetric percentage measurements of oxygen and combustibles, it is possible to optimize the air-fuel ratio and approach the idealized condition of stoichiometric com­bustion. Additionally, monitoring of combustibles will assure a safe margin to prevent combustible mixtures from approaching LEL levels as a result of a malfunction, before boiler startup, etc. When necessary, appropriate regulation of the combustion process can be made to reduce nitrogen oxide (NOx) emissions and resultant air pollution.
The system is composed of the necessary components to educt a flue gas sample, condition it for analysis, and monitor on a continuous basis the percentage content of oxygen and combustible gases (see Figure 2).
When required, multipoint configurations, which automatically monitor from two to twelve points on a time shared basis, are available. Multipoint sequencing utilizes a stepping switch/timer which operates in conjunction with a solenoid valve on each sample input to control the time duration of the inflow. Indicating lights plus a recorder output show which sample points are being monitored at any given time. Override switches can be operated to omit any number of sample points from the monitoring program. If necessary, time delays can prevent the inadvertent tripping of alarms during the sample sequencing.
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General Information Model 9700
2 Sample Conditioning
When the flue gas is drawn into the analyzer system, it enters at a relatively high temperature and carries a significant content of moisture, dirt and corrosives. The sample stream is preconditioned to cool the gases and remove contaminants. This processing of the sample assures clean and continuous operation of the instrument.
A sample stream of flue gas, drawn into the sampling system by negative pressure, flows through a two-way sample-calibration selector valve installed at the sample inlet. The valve is used to introduce sample gas into the system However, when the valve is rotated so that the handle index faces the inside of the case (open port), atmospheric air is drawn into a T-joint where a spray nozzle introduces a fine water mist. This mist cools and wets the sample. A strainer is built into the system to prevent the nozzle from being clogged by particulates in the cooling water.
Figure 1: Model 9700 Analyzer System
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Flue Gas Analysis System General Information
Next, the gas and water mixture enter the pump. The pump contains
no valves or packing and will handle the dirtiest of samples without any detrimental effect
Exiting the pump under positive pressure, the sample mixture is forced through a mixer which contains a series of baffles which function to thoroughly scrub the sample gas.
At the next stage of conditioning, the sample solution enters a separa­tor where water is gravitated to drainage. The scrubbed flue gas sample then exits the separator through a sample outlet and enters a filter-conden­sate trap for final removal of particulates and water before undergoing analysis.
The sample gas stream, having passed the final filtration trap, flows into a tee. Here, the stream is divided with most of the sample gas being vented to atmosphere, while the balance is routed to the oxygen analyzer section. Total flow rate is approximately 20 to 30 SCFH. A back pressure control valve is adjusted to permit proper flow past the oxygen analyzer sensor where the percentage of oxygen concentration in the flue gas sample is determined and displayed on the oxygen analyzer meter.
Following oxygen analysis, the sample passes to the combustible analysis section.
Figure 2: Sample Conditioning
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General Information Model 9700
3 Oxygen Analyzer Section
The analysis system (see Figure 3) employs a Model 326B Analyzer which features a TBE/AI unique, patented Micro-Fuel Cell oxygen sensor. This electrochemical transducer provides an electrical signal that is directly proportional (and specific) to the oxygen concentration in the gas phase immediately adjacent to its sensing surface.
The analyzer is capable of oxygen measurements as small as 0.05% and is unaffected by flow rate changes. Since the sensor is incapable of producing a significant electrical signal without the presence of oxygen, any measurable signal produced is “specific” to oxygen.
The Micro-Fuel Cell is completely enclosed, maintenance-free, and has a predictable life span that is covered by warranty. When the cell is expended, it is discarded in the same fashion as a worn-out flashlight battery. TBE/AI’s extensive line of Micro-Fuel Cell equipped oxygen­measuring instruments are all designed so that the sensor cell can be replaced in a matter of moments by nontechnical personnel without the use of tools.
3 .1Standard Features
The oxygen analyzer is housed in a fiberglass equipment case de­signed to resist the invasion of moisture and dust. The following features are standard in the Model 326B analyzer:
Three Ranges of Analysis
Three ranges of analysis are offered 0–5% (Lo), 0–10% (MED), and 0–25% (HI). Range control is achieved through the positioning of a panel-mounted RANGE selector switch; the switch also controls the power on/off to the analyzer. Since one of the three available ranges of analysis is always 0–25% O2. ambient atmospheric air (20.9% O2) can always be used to calibrate the analyzer. A CAL mark on the oxygen meter scale facilitates calibration. (Although the ranges selected best cover the oxygen content of flue gas, any three ranges of analysis, from 0–1% to 0–100%, can be provided. )
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Flue Gas Analysis System General Information
Figure 3: Oxygen Analyzer Section
Integral Meter Readout The analyzer is equipped with a 5" panel meter for direct
readout of the analysis. A linear scale (mirror equipped to eliminate parallax) promotes reliable, accurate readout of the analysis at any point on the scale. Resolution and accuracy of the meter eliminates the necessity of an accessory readout device, unless permanent recording or remote indication is required.
Output Signal A linear output signal of from 0–1mV dc to 0–1 V dc is
available for those applications requiring a remote indication and/or recording of the sample oxygen. Unless otherwise specified, the output signal will be 0–1 V dc.
Temperature Control and Compensation To eliminate the inaccuracies caused by varying temperature
conditions that are inherent in most methods of analysis em­ploying transducers, a system composed of a combination of temperature compensation and control is used in the analyzer.
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General Information Model 9700
To protect the Micro-Fuel Cell against damage from low ambient temperatures and reduce the range required of the compensation circuit, the analyzer is equipped with a thermostatically controlled heating system that will not permit the interior of the instrument to drop below 85 deg F.
To eliminate inaccuracies accompanying the positive temperature coefficient of the Micro-Fuel Cell, a specially selected thermistor and network of precision resistors are utilized to produce a negative coefficient of matching characteristics .
The variable element (thermistor) in the compensation network is physically located in the same assembly as the Micro-Fuel Cell so that both devices are exposed to essentially the same temperature conditions.
Integral Sample Pump Control Because the analyzer was essentially designed to measure the
oxygen content of flue gas, provisions for powering and controlling an electrically driven accessory sample pump have been built into the analyzer. Terminal strip connections as well as protective fusing are provided. Pump power is controlled through the same RANGE switch that controls analyzer power (see Dwg. B-l0913).
Modular Electronics The analyzer is equipped with integrated circuit (IC)
semiconductor electronics. Components are mounted on a plug­in printed circuit board, as are various optional electronic features, i.e., alarms and converter. Printed circuit assemblies are preset and adjusted for immediate replacement.
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Analytical Instruments
Flue Gas Analysis System General Information
3.2 Optional Features
The following optional features are available with the system.
Integral Alarm Circuitry One (Model 326B-1) or two (Model 326B-2) adjustable, full-
scale alarm and/or control circuits are available.
Control over an external circuit is achieved by a relay whose solenoid coil is operated by an electronic “comparator” circuit. The switch contacts of the relay (NC/C/NO) are available for interconnection with customer circuitry at the terminal strip within the analyzer. The control point at which the analyzer operates is determined by the setting of a calibrated dial-equipped potentiometer on the control panel.
The 0–10% range of the standard Model 326B is directly related to the decade nature of the turns-counting dial; the 0–5% and 0–2% ranges require a simple extrapolation exercise to determine the proper dial reading for a given oxygen level within the limits of their range.
The integral control circuitry can be arranged so the relay is energized above or below the setpoint. Unless otherwise specified, the control relay in a single setpoint instrument (Model 326B-1) will be energized downscale from the set position: relays in a double setpoint instrument (Model 326B-2) will be energized when the oxygen level is reading in the scale region-ion between setpoint #1 in the lower region of the scale) and setpoint #2 (in the upper portion of the scale). These configurations provide power supply as well as oxygen alarm information. The relays are arranged to be in an energized condition when the oxygen concentration of the sample is in the safe region of the scale.
The form “C” SPDT relay contacts are rated at 3 amperes (non-inductive).
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General Information Model 9700
E-to-I Converter A voltage (E) to current (I) conversion of the output signal
generated by the analyzer is available. This conversion allows I (current) to P (pneumatic) devices, as well as low-impedance current-operated indicating and/or recording and controlling instruments to be directly driven without the need of accessory equipment.
One of the following three ranges of current output is available:
1 to 5 mA dc,
4 to 20 mA dc
10 to 50 mA dc.
The designation 326B-I signifies an analyzer equipped with an E to
I converter.
Differential Power Supply Both integral alarm and E-to-I converter options are plug-in
printed circuit boards for quick replacing. When either or both of the options are employed in an instrument, a highly regulated differential power supply (also a plug-in printed circuit board) is included to supply the positive and negative voltage required by the semiconductor circuitry.
The basic Model 326B employs a simple unregulated power supply. The rectifying diodes and filtering capacitors are located on the same circuit board as the detection and amplifier circuitry. The alarm comparator and converter circuits, however, require that the supply voltage remain at a constant level to all circuitry in the interest of accuracy. When options are employed, the unregulated power supply components are deleted from the amplifier board, and the amplifier, as well as the option circuit, are fed from the regulated differential power supply.
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Flue Gas Analysis System General Information
4 Combustible Gas Analyzer Section
The combustibles analyzer (see Figure 4) is a compact detector for
reliably sensing all combustible gases. The analyzer consists of two parts:
(1) The control unit housing the calibration controls, analyzer
circuitry, meter readout, alarm relays and power supply.
2) The sensor unit including the sensor, flowmeters, valves and heater circuit. (Heater power is controlled through the same RANGE switch that controls oxygen analyzer power (see Dwg. B-l0913).
Figure 4: Combustible Gas Analyzer Section
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General Information Model 9700
The sample is sent through one side (SAMP) of twin indicating flowmeters. Since it is necessary that there is sufficient oxygen in the sample being analyzed to insure full combustion of any combustible gases present, the sample is blended, or diluted, with an equal amount of “clean” compressed air. The compressed air is introduced through the second (AIR) of the two flowmeters. Two flowmeters are used so that an equal volume of both sample and air flow can be visually set.
The flowmeters, valves, sensor and associated plumbing are installed within a temperature controlled box. Temperature is held at about 130 deg F to keep all components above the dew point of the sample gas.
The sample stream is routed past the combustible gas sensing element. This element is a low-temperature, catalytic bead type transducer in a constant current-excited Wheatstone Bridge circuit. Two legs of the bridge are exposed to the sample gas. The other two legs are passive elements in the control unit. Gas diffuses into the sensing element and oxidizes at the catalytic surface of the active or measuring bead, causing its temperature to rise. The reference bead is not catalytically coated and, consequently, is not heated by the combustibles. The difference in resistance of the otherwise matched pair of catalytic beads creates a signal in the bridge circuit. Use of the uncoated reference bead compensates for the effects of temperature variations, humidity changes, ambient pressure changes and variations in line resistance. The signal from the bridge is amplified and displayed on a meter with a 0–5% combustible range. A diagrammatic illustration of the combustible sensor is shown in Figure 5.
The beads are installed in a housing which has a flashback arrestor screen at the sensing aperture to prevent flame propagation back into the process.
Response of a catalytic bead sensor to a number of gases is shown in Table I.
An adjustable alarm can be set at any value within the full range. The latching or non-latching alarm relay can be wired to auxiliary lights, horns, fans, or used for equipment shutdown.
At completion of combustibles analysis, the sample stream is vented from the analysis circuit.
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Flue Gas Analysis System General Information
H
TABLE 1: Detector Response To GASES
COMPOUND LEL* RESPONSE FACTOR Methane 5.0 1.00
Hydrogen 4.0 0.86 Carbon Monoxide 12.5 0.32 Ethane 3.0 1.20 Ethylene 2.7 1.26 Acetylene 0.5 1.39 Propane 2.2 1.42 Propylene 2.0 1.33 Butane 1.9 1.54 Hexane 1.1 1.50 Cyclohexane 1.3 1.44 Heptane 1.05 1.59 Benzene 1.3 1.50 Pentane 1.5 1.45 Toluene 1.2 1.48 Ethylene oxide 3.6 0.76 Methyl Ethyl 1.8 0.96 Ketone Methyl Acrylate 2.8 0.59
* Taken from Fire Hazard Properties of Flammable Liquids,
Gases and Volatile Solids, National Fire Protection Agency.
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Figure 5: Combustible Gas Sensor
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General Information Model 9700
4.1 Operating Controls and Indicators
The POWER toggle switch is used to turn the combustible gas analyzer ON and OFF.
The meter displays the gas concentration at the detection point as a percentage of the combustible gas and is graduated from 0–5% combustibles.
The green SAFE light is illuminated during normal operation and indicates that the combustible gas sensing element is operating.
The red ALARM light is illuminated either when the combustible gas concentration rises above the adjustable ALARM setpoint, or in the event of a sensing element circuit malfunction. The two conditions can easily be distinguished by observing the meter reading. In a gas alarm, the meter pointer will be upscale above the predetermined level. In a malfunction type alarm, the meter needle will be pegged downscale below zero. A malfunction alarm will be caused by low or no sensing element current.
(optional) The blue FAILURE light is illuminated in the event of failure of the detector element. The internal buzzer will also be activated with this type of failure.
(optional) The amber CAUTION light is illuminated when the gas concentration rises above the adjustable CAUTION setpoint.
The BUZZER toggle switch enables the internal buzzer to sound if the unit goes into alarm.
Note: This switch is a three position switch. For units that do not contain
a "CAUTION ALARM" , this switch must be in the "full up" position to activate the AUDIO-BUZZER ALARM. The center and "full down" positions are "OFF" conditions.
The AUTO/MAN toggle switch determines the mode of the alarm relay. In the AUTO mode, the alarm relay will pull in and drop out automatically as the gas concentration goes above and below the setpoint. In the MANual position, the alarm relay will be in a latching mode such as to pull in if the gas concentration goes above the setpoint. The alarm system can be reset to normal by switching back to AUTO.
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Flue Gas Analysis System General Information
4.2 Recessed Secondary Controls
NOTE: The recessed potentiometric controls are provided for calibration
purposes. They should not be changed once calibration is estab­lished.
The SPAN control adjusts for manufacturing variations in sensitivity between elements and for various gases.
The ZERO control adjusts for zero meter reading with zero gas (air) flowing through the sample cell.
The ALARM control allows the point at which the unit goes into alarm to be adjusted anywhere between 0% and 5% combustibles as shown by the meter reading.
(Optional) The CAUTION control allows the point at which the unit goes into alarm to be adjusted anywhere within the range of the instrument as shown by the meter indication.
4.3 Meter Trim
The small potentiometer (P5) located on the main circuit board below the meter is used to trim the meter to full scale deflection at the rated output. The potentiometric control is set at the factory.
4.4 Analog Output
An analog (voltage or current) signal is provided for remote monitor­ing or recording. The type of signal is a customer option.
Voltage Output 0–1 Volt full scale or less.
NOTE: The remote meter or recorder should have an input impedance
greater than 1K-Ohm.
Current Output One of the following milliampere outputs may be
provided:
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General Information Model 9700
CURRENT MAX LOAD OUTPUT IMPEDANCE (mA) (Ohms)
4–20 1K
NOTE: The remote meter or recorder should have an input impedance less
than the indicated values.
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