air monitoring combustion air power boilers

1050 Hopper Avenue P.O. Box 6358 Santa Rosa, CA 95406 (707) 544-2706 (707) 526-9970 Fax www.airmonitor.com

Rev. 03/03/05

TABLE OF CONTENTS Power

Full Line Catalog Tab Type Document Name Part Number

1 BENEFITS OF AIRFLOW & COAL FLOW MEASUREMENT Paper ...............Why is it Important to Measure Combustion Airflow and Pulverized Fuel Flow? ...........11/99

2 COMBUSTION AIRFLOW MEASURING SYSTEMS Brochure...........VOLU-probe/SS Stainless Steel Pitot Airflow Traverse Probes ............................... 125-068 Brochure...........CAMS Combustion Airflow Management System .............................................. 125-009 Manual .............Combustion Airflow Measuring Station-Engineering & Design Manual.........................11/97 Brochure...........VELTRON DPT-plus Microprocessor Based Transmitter........................................ 125-025 3 PULVERIZED COAL FLOW MEASURING SYSTEMS Paper ...............NOx Reduction of a 165MW Wall-Fired Boiler Utilizing Air & Fuel Flow Measurement.... N/A Paper ...............Combustion Optimization of a 150MW (net) Boiler ...................................................... N/A Brochure...........Pf-FLO III Pulverized Coal Flow Measurement .......................................................11/04 Paper ...............Pf-FLO Reference Test at the Martin-Luther University Halle-Wittenberg .................... N/A 4 INDIVIDUAL BURNER AIRFLOW MEASURING SYSTEMS Paper ...............Accurate Burner Airflow Measurement for Low NOx Burners D.B. Riley ..................... N/A Paper ...............Balancing Low NOx Burner Airflows through the Use of IBAMS .................................12/98 5 CONTINUOUS EMISSIONS MONITORING SYSTEMS Brochure...........CEM Systems Continuous Emissions Monitoring .............................................. 125-491 6 COMBUSTION AIRFLOW APPLICATIONS Bulletin.............Measuring Primary Airflow (Raymond Bowl Mill) ..................................................... ICA-01 Bulletin.............Measuring Secondary Airflow (Venturi Replacement) .............................................. ICA-02 Bulletin.............Measuring Secondary Airflow (Airfoil Replacement)................................................. ICA-03 Bulletin .............Measuring Secondary Airflow (Tangentially Fired Boiler) .......................................... ICA -04 Bulletin.............Measuring Primary Airflow (Pressurized Mill).......................................................... ICA-05 Bulletin.............Measuring Individual Burner Airflow........................................................................ ICA-06 Bulletin.............Secondary Airflow Measurement (Cyclone Burner).................................................. ICA-07 Bulletin.............Secondary Airflow Measurement (Compartmentalized Burner Duct Work)................. ICA-08 Drawing ............Basic Layout of a Fossil Fuel Boiler .......................................................................... N/A Drawing ............Corner Fired Airflow Measuring Concept .................................................................... N/A Drawing ............Corner Fired Windbox Modifications .......................................................................... N/A Success Story ..Wisconsin Electric Power Company and AMC Power............................................. ISS-01 Success Story ..Consumers Power Company, ABB C-E and AMC Power......................................... ISS-02

November 23, 1999

WHY IS IT IMPORTANT TO MEASURE COMBUSTION AIRFLOWAND PULVERIZED FUEL FLOW?

AMC Power is a pioneer and leader in developing systems to accurately and reliablymeasure combustion airflow, with thousands of installations at virtually every utility inthe United States. While the reasons for improving combustion airflow measurementvary from power plant to power plant, there are common applications at all power plantsthat would greatly benefit from improved airflow measurement. In addition to its manyother benefits detailed below, use of our Pf-FLO pulverized coal flow measurementsystem has had the auxiliary effect of increased awareness of the need to more accuratelymeasure combustion airflow. This report is a compilation of the experiences had bypower plant managers who have installed our systems at their facilities, as well asinformation from published articles on combustion airflow. It will serve to explain thevarious plant enhancements that have been made by implementing AMC Power products.

AMC Powers VOLU-probes unique, patented ability to measure flow in short duct runsmakes it ideally suited to measuring all forms of combustion airflow. Figures 1 and 2 areboiler schematics that depict the typical points of airflow measurement. Figure 1 is awall-fired boiler and Figure 2 is a tangentially fired (T-Fired) boiler. One canimmediately note that the largest problem in measuring combustion airflow is the lack ofstraight duct runs.

Primary AirflowThe main function of primary air is to pneumatically convey the pulverized coal from themill to the individual burners. Primary airflow is also important to the performance oflow NOx burners. Most low NOx burner manufacturers stipulate that accurate primaryairflow measurement must be available in order to meet NOx performance guarantees.This requirement is placed on utilities because excess primary air will elevate flametemperature and therefore increase thermal NOx created at a burner. Primary air alsoaffects coal velocity and therefore the position of the flame relative to the burner tip. Formost low NOx burners both the flame temperature and position are critical to reducingNOx. As such, accurate primary airflow measurement and control has become a criticalcomponent in the process of minimizing NOx levels throughout the entire load range ofthe boiler operation. While decreasing primary air at lower loads is important tominimizing NOx, one must be aware that a minimum transport velocity has to bemaintained to avoid reaching the point where coal particles start falling to the bottom ofthe pipe in horizontal runs. This phenomenon, referred to as layout, can cause problemswith burner performance, coal pipe fires and slugging (or surging) of coal into theburners.

The NOx reduction benefit resulting from properly managed primary airflow is not justlimited to plants equipped with low NOx burners. Tight control of the primary air canhelp reduce flame temperature on any burner, place the flame where it needs to be foroptimum combustion, and reduce water wall damage caused by flame impingement onthe opposing furnace wall.

November 23, 1999

Location (A) is typical for a primary airflow station on a pressurized coal pulverizer(mill). In many cases, there is ample straight run after the hot and tempering air mix tomeasure at this location for the purpose of controlling the volume damper into the mill.Either VOLU-probes or a Combustion Air (CA) Station can be installed in the duct andused along with a Combustion Airflow Management System (CAMS) for generating amass flow output.

Locations (B) and (C) are hot and tempering primary airflow respectively. In addition tohaving the correct primary air volume to transport the coal particles to the burners,primary air temperature control is also important for drying the coal in the mill. In orderfor all surface moisture of the coal to be evaporated, mill outlet temperature must beaccurately measured and controlled by means of modulating the hot and temperingairflows. These flows can be measured individually using VOLU-probes or CA stations,and CAMS, with separate control of the hot and tempering air dampers, or they can besummed (by the CAMS) to give a total primary airflow signal, which can be used tocontrol mass flow of the air to the mill with the mill PA volume damper.

Bulk Secondary AirBulk secondary air is the airflow feeding the windbox, which is then distributed to theindividual burners. Most coal fired boilers have archaic flow measuring devices (if anyat all) such as venturis or airfoils, for measuring bulk secondary air. Airflow traversing,normally utilizing Pitot tubes (standard or S-type), is required to in situ calibrate venturisand airfoils. Since most Pitot traverse methods require more straight run than is typicallyavailable, accurate secondary airflow measurement does not exist at most power plants.More importantly, these inaccurate flow measuring devices, by nature of their design,create significant amounts of permanent pressure drop. By removing and replacing themwith AMC Power systems (usually VOLU-probes and CAMS), not only is measurementaccuracy improved, but an increase in plant output is also realized through the decrease inenergy consumption needed to overcome the pressure drop. In many plants that are FDfan limited the removal of foils and venturis and their replacement with AMC Powersystems has allowed them to increase MW output. FD fan limitation usually occurs inthe summer when less dense air prevents the fan from delivering the mass flow neededfor maximum MW generation. It is in the summer months that the demand for and valueof generated power is at its greatest, and therefore the economic justification of thismodification is most apparent.

Location (D) is typical for wall fired boilers. The preferred measurement location isdownstream of the fan, preheater and primary air takeoff (as shown), but it can be madein other locations if necessitated by duct layouts. On an opposed wall-fired unit,secondary airflow measurement may also be important to balancing front and rearwindboxes.

If the boiler has partitioned windboxes (Figure 3), balancing burner elevations alsobecomes important when attempting to reduce NOx and LOI, as well as addressingslagging problems.

November 23, 1999

Locations (F) through (I) are typical on four-cornered T-Fired boilers. In addition to thepossible FD fan limitation problems, many T-fired boilers have airflow balance problemsthat result in improper fireball positioning. Measuring and controlling secondary airflowto each corner can help position the fireball in the center of the furnace, therebyeliminating or reducing corrosion, LOI and/or NOx problems associated with having richand lean corners in the boiler rather than balanced combustion.

Individual Burner Airflow Measurement (IBAM)Though total secondary airflow can and should be accurately measured for boiler loadcontrol, the imbalances in secondary air delivered to the boiler via its multiple burnershas created performance and emission problems for effectively every utility. Whether itbe on open windbox boilers (Figure 1) , partitioned windbox boilers (Figure 3) or T-Firedboilers (Figure 2), burner-to-burner secondary air balancing has historically been difficultif not impossible to achieve. AMC Powers IBAMs are designed to be located in thesecondary air register or barrel of each burner so that airflow to each burner can bemeasured (see Figure 4), and subsequently adjusted or controlled by means of eachburners secondary air shrouds. Because most burner configurations do not allow forsufficient straight duct run (even for AMC Powers technology), AMC Power hasperformed wind tunnel testing/calibration that has facilitated the design and commercialdevelopment of the IBAM probe for most low NOx burner types. This allows for theimplementation of instrumentation that can be used to balance burners at start-up usingonly IBAMs. For T-fired units, secondary airflow measurement to the burners can beaccomplished by partitioning the corner windboxes and installing VOLU-probes at eachburner elevation (Figure 5). When AMC Powers CAMS are used, burner balancing canbe dynamically maintained online throughout the entire load range.

Overfire Air (OFA)Overfire air is introduced in the upper part of the furnace above the burners. Plants thatuse OFA operate their burners sub-stoichiometrically, and then extend the combustionprocess into the upper part of the furnace where OFA is introduced. Typically, OFA is20% of the total stoichiometric air. Because OFA is taken out of the windbox, it mostlikely affects (takes air from) some burners more than others, depending on the locationof the OFA take-offs. Measurement and adjustment of individual burner airflows istherefore even more important when implementing an OFA system. OFA measurementis accomplished using VOLU-probes or CA stations along with CAMS.

Cyclone BurnersThe most successful, widespread use of OFA with individual burner airflow measurementhas been on cyclone boilers (Figure 5). Cyclone burners come equipped with anineffective airflow measuring device that uses a perforated plate inlet screen to create alarge pressure drop. These inlet screens are field calibrated using a Pitot traverse in thehighly turbulent cyclone inlet, and as a result are not very accurate, prohibiting plantsfrom being able to balance airflow between cyclone burners. In the normal course ofoperation these screens often get damaged, further reducing their ability to provideuseable airflow measurement. Additionally, the permanent pressure drop (several inches

November 23, 1999

of water) induced by the inlet screens is a significant and unnecessary waste of FD fanenergy that can be put to better use. With the scheduled installation of selective catalyticreduction (SCR) systems into many cyclone boilers (and pulverized coal (PC) firedboilers), extra fan capacity will be required to overcome the hardware that will beinstalled in the ductwork. Removing flow obstructions such as the inlet screens (orventuris and foils on PC units) can help recover the extra fan capacity required. AMCPower developed a product specifically designed to measure airflow at the cycloneinlets (the VOLU-probe/VS-CI). This product has been tested for accuracy in a windtunnel using a full-scale 10 ft. cyclone inlet. By using the VOLU-probe/VS-CI in thesecondary air, VOLU-probes in the primary/tertiary air and CAMS, accurate airflowmeasurement can be performed, which allows for balancing or biasing of cyclones foroptimum efficiency while reducing emissions.

Pulverized Fuel Flow MeasurementIn addition to AMC Powers successes in the area of combustion airflow, the Pf-FLOpulverized coal flow measurement system is currently being applied at many utilitypower plants, giving them the ability to balance coal flow to their burners.

As previously stated, pulverized coal is pneumatically transported via the primary airfrom the mills to the burners, with one mill supplying pulverized coal to as many as eightindividual burners. The majority of mills use splitter boxes, mechanical separators ororifice plates to distribute pulverized coal to the individual burners. Although theintention of these devices is to ensure an equal mass flow of coal is delivered to eachburner, in practice the flow through each coal pipeline generally varies 20% or more.This unbalanced distribution of coal adversely affects the burners air-to-fuel ratio,leading to decreased combustion efficiency, furnace slagging, and irregular heat releasewithin the combustion chamber.

The Pf-FLO coal flow measurement system has been developed to determine the massflow distribution and transport velocity of pulverized fuels in the pipelines from the millto the individual burners. The Pf-FLO system enables the balancing of fuel mass flowdelivered to the burners. In combination with continuous measurement of burnersecondary airflow using AMC Powers IBAM, individual burner air-to-fuel ratios can becontrolled to achieve optimum combustion performance at varying loads, whilesimultaneously reducing both NOx and unburned carbon.

As you can see, AMC Powers equipment offers many performance enhancement andcost reduction solutions that address the two most important issues faced by the PowerIndustry today: NOx reductions as mandated by the Clean Air Act, and efficiencyimprovements needed to remain competitive in a deregulated market.

November 23, 1999

VOLU-probe/SSStainless Steel Pitot Airf low Traverse Probes

Proven solutions for a tough industry

The VOLU-probe/SS Stainless Steel Pitot Airflow Traverse Probeis ideally suited for new installations or retrofit applicationsrequiring accurate airflow measurement in locations having limitedstraight duct runs. Multiple sets of total and static pressure sensingports along the entire length of the VOLU-probe/SS traverse theairstream in a single line across the duct, and average the sensedpressures in separate manifolds. An array of VOLU-probe/SS

probes are used to properly sense the typically stratified flow toprovide an equal area traverse of an entire duct cross-section. TheVOLU-probe/SS is suited for clean or harsh and particulate ladenapplications, operating at temperatures ranging from 20 to 900F.As a primary flow sensing means, the VOLU-probe/SS can be usedin industrial process applications ranging from power generation(combustion airflow), fiber quenching, process drying, emissionmonitoring, etc.

Product Description

VOLU-probe/SS

When installed per AMC Power's Minimum InstallationRequirements (see back page), the minimum quantity and placementof VOLU-probe/SS airflow traverse probes shown below will produceassured measuring accuracies of 2-3% of actual airflow.

Accuracy

All recognized flow measurement standards (ASHRAEFundamentals, AMCA Publication 203, Industrial VentilationManual, 40CFR60, etc.) agree that accurate airflow measurement ishighly dependent upon the quantity and pattern of sensing points inthe airstream, and the relative position of the sensing points toupstream/downstream flow disturbances.

static sensor experiences a lower pressure (Ps part of Pt) of thesame magnitude, thereby canceling out the undesired effect ofpartial total pressure (Pt). It is this unique design of offset staticpressure and chamfered total pressure sensors (see Figure 1) thatmake the VOLU-probe/SS insensitive to approaching multi-directional, rotating airflow with yaw and pitch up to 30 fromstraight flow, thereby assuring the accurate measurement of thesensed airflow rate without the presence of an airflow straightenerupstream. This unique design of the VOLU-probe/SS is coveredby U.S. Patent No. 4,559,835.

How It Works

The VOLU-probe/SS operates on the Fechheimer Pitot derivativeof the multi-point, self-averaging Pitot principle to measure thetotal and static pressure components of airflow. Total pressuresensing ports, with chamfered entrances to eliminate air directioneffects, are located on the leading surface of the VOLU-probe/SSto sense the impact pressure (Pt) of the approaching airstream (seeFigure 2). Fechheimer pair of static pressure sensing ports,positioned at designated angles offset from the flow normal vector,minimize the error inducing effect of directionalized airflow. Asthe flow direction veers from the normal, one static sensor isexposed to a higher pressure (Ps + part of Pt), whereas the other

Figure 1 Figure 2

The VOLU-probe/1SS is designed for mounting in ducts or stacksby drilling two holes in opposing walls, without the need to enterthose structures.

The VOLU-probe/1SS is furnished with a threaded end support,gasketed washer and nut, and a mounting plate with signal take-offFPT connections, all fabricated of type 316 stainless steel.

VOLU-probe/1SS Externally Mounted

VOLU-probe/1SS & 2SS

The VOLU-probe/2SS is designed for larger ducts or stacks wherethe size permits entry for installation, or where duct externalaccessibility or clearance is insufficient to permit probe mountingfrom outside the duct.

The VOLU-probe/2SS is furnished with interior mounting and endsupport plates, and midpoint signal take-off FPT connections, allfabricated of type 316 stainless steel.

VOLU-probe/2SS Internally Mounted

VOLU-probe/SS Construction Options

VOLU-probe/SS Options

150 lb. Mounting Flange Probe End Supports

Temperature Probe Companion Mounting Plates

Construction Features

Stainless Steel Airf low Traverse Probes

Features

Provides for Equal Area Traverse. Each VOLU-probe/SScontains multiple total and static pressure sensors specifically andprecisely located along the length of the probe to provide an equalarea traverse of ducted airflow. For rectangular duct configurations,the sensors are spaced at equal distances along the probe. Forcircular duct configurations, the sensors are located at the centersof the equivalent concentric area along the probe.

True Velocity Pressure Measurement. The total and staticpressure components of airflow measured by the VOLU-probe/SScan be directly converted in velocity pressure (and velocity) withoutthe use of correction factors, thereby facilitating flow verificationwith a Pitot tube or other hand held instrumentation.

No Sensor Protrusions. The VOLU-probe/SS total and staticpressure sensors are all contained within the confines of the externalsurface of the probe. There are no protruding sensors to be bent,broken, or otherwise damaged during installation or possiblesubsequent removal for inspection or cleaning.

Rugged Construction Assures Long Service Life. The standardVOLU-probe/SS is fabricated from Type 316 stainless steel usingall welded construction. See Page 4 for construction options, andcontact Factory for alternate materials of construction such asHastelloy, Inconel, Kynar, PVC, etc.

No Air Straighteners Required. The VOLU-probe/SS uniquedual offset static pressure sensor and patented chamfered totalpressure sensor design permit the accurate measurement of theairflow rate in highly turbulent flow locations (with directionalyaw and pitch varying up to 30 from the duct's longitudinal axis)without the need for upstream air straightening means.

Offered in Two Models. The VOLU-probe/SS is offered in twobasic configurations to facilitate installation in new or existingducts or stacks; the Model 1 for external mounting, and the Model2 for internal mounting.

Negligible Resistance to Airflow. The VOLU-probe/SScylindrical configuration and smooth surface free of external sensorprotrusions permit the airstream to flow unrestricted around andbetween the installed traverse probes, creating a very minimal, ifnot negligible resistance to airflow (Ex: 0.046 IN w.c. at 2000 fpmair velocity).

Performs Equal-Weighted Averaging of Flow Signals. Throughthe use of separate averaging manifolds, the VOLU-probe/SSinstantaneously averages, on an equal-weighted basis, the multiplepressures sensed along the length of the probe, producing separate"averaged" total pressure and static pressures at the probe's externalsignal connections.

FPT Signal Connections

Offset Fechheimer Static Pressure Sensors

Integral 10 Gauge Mounting Plate

Chamfered Total Pressure Sensors

Note: VOLU-probe/SS locations shown are not ideal. The locations indicate the minimum clearance required from air turbulence producingsources. Wherever possible, the VOLU-probe/SS should be installed where greater runs of straight duct (or clearances) than shown belowexist.

Minimum Installation Requirements

125-068 (1/99)

VOLU-probe/SS

Suggested Specification

Provide where indicated an array of airflow traverse probes capableof continuously monitoring the stack or duct capacities (air volumes)it serves.

Each airflow traverse probe shall contain multiple total and staticpressure sensors and internally connected to their respectiveaveraging manifolds. The flow sensors shall not protrude beyondthe surface of each probe, and shall be the offset (Fechheimer)type for static pressure and the chamfered impact type for totalpressure measurement. The airflow sensing probe's measurementaccuracy shall not be affected by directional flow having pitch and/or yaw angles up to 30.

Each airflow traverse probe shall be fabricated of type 316 stainlesssteel, all welded construction, and shall be furnished with the flator curved plate mounting means. In addition, access ports andaccessory hardware shall be provided to facilitate external

installation of the probe and end support (if required), yet permittingeasy probe removal for inspection, etc.

The airflow traverse probe shall not induce a pressure drop in excessof 0.046 IN w.c. at 2000 FPM, nor measurably contribute to soundlevels within the duct. Total and static pressure sensors shall belocated at the centers of equal areas (for rectangular duct) or atequal concentric area centers (for circular ducts) along the probelength. The airflow traverse probe shall be capable of producingsteady, non-pulsating signals of total and static pressure withoutneed for flow corrections or factors, with an accuracy of 2-3% ofactual flow, over a velocity range of 400 to 4000 FPM.

The airflow traverse probe(s) shall be the VOLU-probe [1SS, 2SS]as manufactured by AMC Power, Santa Rosa, California.

3X 1.5X 5X 2X 1X 4X

CENTRIFUGAL FAN CENTRIFUGAL FAN VANE-AXIAL FAN DISCHARGE VANE-AXIAL FAN INLET DISCHARGE INLET

FANS DAMPERS

ELBOWS TAKEOFFS

DUCT TRANSITIONS

X X1.5X 2 2X 2

2X

90 VANED ELBOW ROUND SWEEP 3XELBOW

X5X 1X 2X 2 3X 1X

90 UNVANED ELBOW SWEEP ELBOW

1 X

X 1X 2

X

X 1X 2 1X 2

TRANSITION ANGLE: < -15 TRANSITION ANGLE: < -15 TRANSITION ANGLE: < -15 TRANSITION ANGLE: < -15

X2

( )Rectangular Duct: x = Circular Duct: x = Duct Diameter2 H x WH + W

P.O. Box 6358 Santa Rosa, CA 95406 TEL 800-AIRFLOW Fax 707-526-9970 www.airmonitor.com

CAMSCombustion Airflow Management System

TM


The AMC Power's CAMSTM Combustion Airflow ManagementSystem is designed to fulfill the need for a reliable and accuratemeans of flow measurement in combustion airflow applications.Combined into a single engineered package are the CAMMTMCombustion Airflow Management Module containing the

microprocessor based instrumentation to measure the airflow andmanage the purge cycle, and the AUTO-purge III to protect againstany degradation in performance of the duct mounted measurementdevice(s) due to the presence of airborne particulate.

Product Description

CAMS Combustion Airflow Management SystemTM

CAMMTM Performance Specification

Accuracy.0.1% of Natural Span, including non-linearity, hysteresis,and non-repeatability.

Stability.0.5% of Natural Span for six months.

Temperature Effect.Zero: None; corrected by AUTO-zero.Span: 0.015% of Full Span/F.

Power Consumption.54VA at 24VAC; 48VA at 24VDC; 108VA at 120VAC.

CAMMTM Functional Specification

Digital Output.Separate Form "A" dry contacts (maintained) forAUTO-purge activation and acknowledgment.

Digital Inputs.Separate dry contacts (momentary) for AUTO-purgeexternal start and purge interrupt commands.

Analog Outputs.Four standard outputs for flow, temperature, absolutepressure, and special function individually configurablevia jumper for 0-5VDC, 0-10VDC, or 4-20mADC.

Analog Inputs.Dual inputs are field configurable via jumper for 0-5VDC,0-10VDC, or 4-20mADC. One is reserved for temperatureinput; the other for use with special function.

AUTO-purge Management.AUTO-purge cycle is initiated via an external dry contact(momentary), or via an internal timer with field selectablefrequencies of 1 to 24 hours, in 1 hour increments.

Low Pass Filtration.Response time to reach 98% of a step change is adjustablefrom 2.0 to 250.0 seconds.

Power Supply.Standard 24VAC (20-28VAC) or 24VDC (20-40VDC),with automatic selection. Optional 120VAC (100-132VAC) via external UL listed transformer.

Overpressure and Static Pressure Limit.25 psig.

Automatic Zeroing.Accuracy. Within 0.1% of calibrated span.Frequency. Every 1 to 24 hours selectable on 1 hour

intervals.

Circuit Protection.Power input is fused and reverse polarity protected.

Span and Zero Adjustment.Digital, via internally located push-buttons.

Displays.Standard 4 line x 20 character LCD provides four lines ofdata display.

Temperature Compensation Selection.Push-button selection of linearized or nonlinear input.Choice of thermocouple (Type E, K, J, and T) or 100 ohmplatinum RTD temperature sensor type.

Pressure Compensation.Absolute pressure (atmosphere or duct static), up to60"Hg.

Humidity Limits.0-95% RH, non-condensing.

Temperature Limits.20F to 180F Storage.+40F to 120F Operating.

Special Functions Certification Rapid Stop Summed Flow Standard Yes Differential Flow NIST Traceable No

CAMMTM Construction Options

AMC Power's AUTO-purge III is designed for applications wherethe presence of airborne particulate might impair the measurementaccuracy of AMC Power's Combustion Air Station or VOLU-probearray. When activated by a CAMMTM or distributed control system,a combination of fail-safe valves are operated to introduce high

pressure/high volume air to the flow measuring device's sensingports for a short duration, while simultaneously isolating theCAMMTM from overpressurization. This periodic purging assistsin maintaining the sensing ports of the total and static pressuremanifolds in a clear, unobstructed condition.

Product Description

AUTO-purge III

NOTE: CAMSTM with Rapid StopTM option requires an enclosure that is 24" wide by 30" high.

NEMA 4X Stainless Steel Enclosure Vortex Cooler. Requires 80-100 psi air supply. Rapid StopTM

Power 24VAC 24VDC 120VAC

Optional Construction

Dimensional Specifications

Brass and Copper Construction All wetted tubing, fittings, and valves constructed of copper and/

or brass. Enclosure is NEMA 4 painted steel. External connection fittings are stainless steel FPT.

Standard Construction

AUTO-purge III

Sequence of Operation

Automatic line purging disconnects the CAMMTM from the processsignal lines at regular field selectable intervals and purges theairflow station or probe array with up to 125 psig air for shortperiods. This periodic purging assists in maintaining the sensingorifices of the total and static pressure manifolds in a clean,unobstructed condition.

A selectable timing sequence provided by the CAMMTM activatessolenoid pilot valve SV-1 which shuttles the CAMMTM isolationvalves (V-3 and V-4) and purge valves (V-1 and V-2). A simul-taneous output signal hold corresponding to the last measured inputis initiated by the CAMMTM and maintained until the purge cycleis complete.

When valves V-1/V-3 and V-2/V-4 operate, velocity pressure signallines to the CAMMTM are isolated, and high pressure purge air(AS1) is routed via the process signal lines (A and B) to the station/probe array, cleaning the total and static pressure sensing ports.

At the end of the purge cycle the CAMMTM withdraws its purgesignal, de-energizing SV-1 and causing valves V-1/V-2 and V-3/V-4 to reset after a short time delay to their normal position, therebyreconnecting the process signal lines to the CAMMTM. After ashort timed interval the CAMMTM signal hold is terminated andon-line signal processing resumes.

Purge Cycle Timing

CAMMTM Standard CAMMTM with Rapid StopTM

Schematic

IDENTIFICATION CODE

V-1,3 Pneumatically Piloted, 5-WayValve, Static (low) Pressure

V-2,4 Pneumatically Piloted, 5-WayValve, Total (high) Pressure

SV-1 Solenoid Operated, 5-Way ValveSV-2 Solenoid Operated, 3-Way ValveHV-1 Supply Air Shut Off ValvePI-1,2 Gauge, Supply Air Pressure,

0-160 psigPRV-1 Pressure Regulator

SV-3A,3B Solenoid Operated, 3-Way Valve(Optional for Rapid Stop)

CAMM Combustion Airflow Management ModuleTM


Removabletop cover.

External, unitary plug-interminal strips for field

wiring connections.

ON-OFF power switch.

Integral liquidcrystal display.

Aluminum NEMA 1enclosure.

Instrumentmounting bracket.

Features

Analog Communication. Each analog input and output signal canbe individually configured for 0-5VDC, 0-10VDC, or 4-20mADCby means of a single jumper.

Primary Signal Noise Filter. To eliminate background noise andpulsations from the flow signal, the CAMMTM is equipped with auser selectable digital low pass filter.

Air Density Correction. The CAMMTM is capable of performingboth air temperature and air pressure correction. Temperature inputis an analog signal from a remote temperature transmitter; non-linear temperature inputs can be linearized by the microprocessor.Process pressure is measured by means of an internal absolutepressure transducer connected to the transmitter static pressuresignal input.

AUTO-purge Management. The CAMMTM provides the capabil-ities of establishing purge frequency and duration while giving theuser a choice of either internally timed cycle frequency or externallytriggered purge initiation. During the purge cycle all transmitteroutputs are maintained at their last value prior to the start of thepurge cycle. Upon receipt of a dry contact input, the CAMMTMwill interrupt a purge cycle in progress and return to normaloperation.

Optional Rapid StopTM. The Rapid StopTM valving combined withpurge sequence timing in the CAMMTM permits a reduction of therecovery portion of an AUTO-purge cycle from a typical 30 secondsto as short as 5 seconds.

Accuracy. The CAMMTM is designed to maintain a measurementaccuracy of 0.1% of natural full span. For a span of 0 to 0.05 INw.c., this accuracy is equivalent to an output accuracy of 0.00005IN w.c. differential pressure or 0.90 FPM velocity.

Continuous Display of Process. All CAMMsTM are equipped witha 4x20 backlit liquid crystal display (LCD) for use during theconfiguration and calibration process, and to display four lines ofoutput data (Flow, Temperature, Absolute Pressure, or SpecialFunction) during normal operation, with each line individuallyscalable in user selectable units of measure.

Special Functions Capability. Built into the CAMMTM micro-processor is the capability to perform special application functionsinvolving two transmitters. Using a second transmitter as an input,the CAMMTM can compute the sum of, or differential between thetwo measured flows. The special function output can be bothdisplayed and provided as an analog output signal.

Microprocessor Based Functionality. The CAMM'sTM on-boardmicroprocessor performs the functions of operating parameterselection, transmitter configuration, input/output and display signalscaling, density correction, and transducer calibration. Input to themicroprocessor is via pushbutton.

High Turndown Ratio Operation. The CAMMTM, with its highlevel of accuracy and automatic zeroing circuitry, can maintain linearoutput signals on applications requiring flow measurementturndown of 10 to 1.


Installation Guide

Ambient Temperature

40F to 120F. For ranges above or below this ambient temperature, use of panel

heater and/or cooler is required.

Accumulator Tank (strongly recommended)

Requires coalescing filter, pressure regulator, and check valve atthe tank inlet.120 gallons All CA stations.120 gallons Multiple VOLU-probes having a combined length

greater than 10'. 80 gallons One or more VOLU-probes having a combined

length less than 10'.

Line from Accumulator Tank to AUTO-purge Panel

25' maximum length, /" pipe (minimum). Recommend locating accumulator tank as close as possible to

CAMSTM Panel.

Electrical Power Requirement

54VA at 24VAC; 48VA at 24VDC; 108VA at 120VAC. 120VAC, 10 amp when an optional enclosure heater is installed.

Air Requirement

80 to 125 psig at 100 CFM, oil and dirt free. 1 to 24 purge cycles per day, with a field selectable duration

between 30 and 120 seconds during which compressed air isreleased.

Line Size

If distance from CAMSTM Panel to Flow Measuring Station orProbes is less than 25', tube size to be /" O.D. Wall thicknessno greater than 0.065".

If distance from CAMSTM Panel to Flow Measuring Station orProbes is 25' to 50', tube size to be /" O.D. Wall thickness nogreater than 0.065".

If distance from CAMSTM Panel to Flow Measuring Station orProbes is greater than 50', tube size to be 1.0" O.D. Wall thicknessno greater than 0.065".

Purge Frequency

Dependent upon the particulate concentration in each application. Adjustable in hourly increments; once per day the minimum

frequency, and once per hour the maximum frequency.

Purge Cycle Duration

Dependent on sensing line size, length, and routing. Minimum: 60 seconds normal; 5 seconds with Rapid StopTM. Maximum: 150 seconds.

CAMS Combustion Airflow Management SystemTM

Field Wiring Diagrams

125-009-00 (5/00)

ENGINEERING & DESIGN MANUAL

For

MODEL CA

Combustion Airflow Measuring Systems

Combustion Airflow Measuring Systems

11/97Proven solutions for a tough industry

MODEL CA - COMBUSTIONAIRFLOW MEASURING STATION

PAGE NO.

AIRFLOW PROCESSING .............................................................................................................. 1

CONSTRUCTION STANDARD AND OPTIONAL ................................................................... 2

SUBMITTAL SHEETS

Combustion Airflow (CA) Station - Rectangular ............................................................................. 3 Combustion Airflow (CA) Station - Rectangular w/Sensing Manifold Cleanout Plugs ................... 4 Combustion Airflow (CA) Station - Circular ................................................................................... 5 Combustion Airflow (CA) Station - Circular w/Sensing Manifold Cleanout Plugs ......................... 6 AUTO-purge III ................................................................................................................................. 7 AUTO-purge III - Installation Guide ................................................................................................. 8 AUTO-purge III - Sequence of Operations .......................................................................................... 9

OPERATION & MAINTENANCE ............................................................................................... 10

COMBUSTION AIRFLOW (CA) STATION - DESIGN & INSTALLATION GUIDE ......... 11

VELOCITY VS. RESISTANCE CHART .................................................................................... 12

PHOTOGRAPHS OF STATIONS

Combustion Airflow (CA) Station - Circular .................................................................................. 13 Combustion Airflow (CA) Station - Rectangular w/Bellmouth ....................................................... 14

TABLE OF CONTENTS


Any physical structure placed across the flow of air in a ductwill impede the flow, the magnitude of which is a function ofthe size and shape of the structure and the quantity of airpassing through it. The AMC Power air processing stationswere developed to produce a minimum of restriction to airflowby utilizing special open parallel cell honeycomb structureswith free areas of 96% or more. These AMC Power airprocessing stations perform the basic conditioning functionsof straightening and equalizing the airflow.

The Model CA Combustion Airflow Measuring Station utilizesa 1" cell, hexagonal pattern, parallel cell, heavy duty weldedhoneycomb that functions as a combination air straightenerand equalizer. The 96%+ free area minimizes undesirablepressure drop on the airstream, while the 16 to 1 ratio of

peripheral area of each passage to its cross-sectional areaproduces a slight drag on the passing air. Since the drag orresistance to airflow varies with the square of the air velocity,the higher velocities are reduced while the lower velocities arepermitted to increase. In the illustration below, the arrowsrepresent the velocity magnitude after the air equalizingsection.

The process of air straightening simply removes the rotational,turbulent flow from the airstream, and directionalizes thatairflow while not significantly altering the velocity profile ofair passing through the material. Removal of rotational,multi-directional airflow is essential to the separation andaccurate measurement of the total and static pressures of theairstream.

AIRFLOW PROCESSING

1


STANDARD CONSTRUCTION

Casing. 3/16" carbon steel. Continuous welded seams. Casing depth is 12".

Flanges. Rectangular Stations: 2" wide, 90 degree formed flanges.Circular Stations: 3/16" x 2" barstock or 3/16" plate flanges, fusion welded.

Air Equalizer. 1" hexagonal, parallel cell equalizer-straightener 3" deep. .024" thick (24 ga) carbon steel.

Total Pressure Sensors and Manifold. All fabricated from Type 316 stainless steel, welded construction. Rectangular Stations: Multiple 5/64" I.D. impact sensors on " O.D. arms, connected to 1-1/8" O.D. averaging manifolds. Circular Stations: Multiple 5/64" I.D. impact sensors on multiple manifolds that are interconnected for signal averaging.

Manifold sizes on circular stations vary from " O.D. to 1" O.D. depending on unit diameter.

Static Pressure Sensors and Manifolds. All fabricated from Type 316 stainless steel, welded construction.

Rectangular and Circular Stations. Multiple 3/64" offset (Fechheimer) sensors on " O.D. averaging manifolds.

Internal Signal Lines. " O.D., Type 316 stainless steel tubing welded to sensor manifolds and extended beyond casing exteriorvia " stainless steel compression fittings.

Finish. All internal and external black steel parts are provided without any special finish.

Packaging. Assembled station is crated in appropriate plywood and/or composition board over the entire air entering and leavingopenings. Entire unit is crated in dimensional lumber for protection during shipment and storage.

CONSTRUCTION

OPTIONAL CONSTRUCTION

Manual Cleanouts. Each total and static pressure manifold arm is extended through the casing wall and terminates in a femalepipe thread and plug. Removal of the plugs permits cleaning of the manifold interiors with compressed air and/or wire brushing.

AUTO-purge Control Panel. An automatic high pressure air purge system, with valving, delay relays, timer, etc., toautomatically activate a compressed air purge of the mass flow traverse probes at pre-determined time intervals. The systemshall isolate the mass flow transmitter input signal lines, lock the transmitter output signal at the last sensed value, and applyhigh volume, high pressure air to the probe manifold via a permanently connected piped air source to dislodge any particulatebuild-up at the sensor holes, as well as to discharge any accumulated particulate that may have collected in the probe manifold.To maximize the effectiveness of the automatic air purge, each manifold shall be individually purged (one at a time). All valvesand electronic circuitry are mounted in a NEMA 4 enclosure.

Protective Coatings. Two coats of oxide paint primer on casing interior, exterior, and/or air straightener surfaces.

Temperature Sensors. Single or multiple point (depends on unit size) thermocouple or RTD probes can be included in themeasuring station to provide temperature readout and/or thermal adjustment for mass flow. Type, size, and temperature rangeof the thermal probe to be customer or factory specified as required for each application.

NOTE

Alternate special construction requirements such as 1/4" or 3/8" casing thickness, large flanges,alternate materials of construction (Type 316 or 316L stainless steel, hastelloy, etc.) are available.

Contact the factory to discuss any unique or special construction needs.

2

SUBMITTAL SHEET

P.O. Box 6358 Santa Rosa, CA 95406 (707) 544-2706 (707) 526-2825 Fax

SUB-Q005, Rev. 3 (7/99)

COMBUSTION AIRFLOW (CA) STATIONRECTANGULAR


Casing. 3/16" carbon steel, continuous welded.Flanges. 2" wide, 3/16" carbon steel formed 90.Air Straightener. 1" hexagonal cell, 3" deep, 0.022" thick, carbon steel.Total Pressure (T.P.) Manifolds. Type 316 stainless steel.Static Pressure (S.P.) Manifolds. Type 316 stainless steel.Signal Connection Fittings. 1/2" FPT, 316 stainless steel. (Units with more than 24 T.P. sensors require 3/4" FPT.)


1/4" carbon steel casing and formed flanges. Casing and flanges painted with iron oxide primer. Special flanges. Temperature sensor and transmitter capable of 4-20mA output. Factory drilled bolt holes. Bellmouth on air intake side.

DIMENSIONAL SPECIFICATIONS

3.2.4

SUBMITTAL SHEET


SUB-Q008, Rev. 3 (7/99)

COMBUSTION AIRFLOW (CA) STATIONCIRCULAR with Sensing Manifold Cleanout (C.O.) Plugs


Casing. 3/16" carbon steel, continuous welded.Flanges. 2" wide, 3/16" carbon steel, welded to casing.Air Straightener. 1" hexagonal cell, 3" deep, 0.022" thick, carbon steel.Total Pressure (T.P.) Manifolds. Type 316 stainless steel.Static Pressure (S.P.) Manifolds. Type 316 stainless steel.Signal Connection Fittings. 1/2" FPT, 316 stainless steel. (with more than 24 T.P. sensors require 3/4" FPT.)Manual Cleanout (C.O.) Plugs. 3/8" FPT, carbon steel.


" carbon steel casing and plate/bar flanges. Casing and flanges painted with iron oxide primer. Special flanges. Temperature sensor and transmitter capable of 4-20mA output. Factory drilled bolt holes. Bellmouth on air intake side.


3.4.2

SUBMITTAL SHEET

P.O. Box 6358 Santa Rosa, CA 95406 (707) 544-2706 (707) 526-2825 Fax www.airmonitor.com

SUB-M004, Rev. 7 (10/05)

AUTO-purge III


q Brass and Copper Construction All wetted tubing, fittings, and valves constructed of copper and/or brass.Enclosure is NEMA 4 painted steel.External connection fittings are stainless steel FPT.

q Stainless Steel Construction All wetted tubing, fittings, and valves are constructed of 316 stainless steel.Enclosure is NEMA 4 painted steel.External connection fittings are stainless steel FPT.


q NEMA 4X Stainless Steel Enclosure SV-1 / SV-2q Enclosure Heater. Requires 120VAC power supply. q 24VAC, 36VAq Vortex Cooler. Requires 80-100 psi air supply **. q 24VDC, 36VAq Continuous Enclosure Purge **. q 120VAC, 36VA** These options require a 24 X 24 enclosure.


8.28.2

SUBMITTAL SHEET


SUB-M009, Rev. 5 (8/01)

AUTO-purge IIIINSTALLATION GUIDE

Air Requirement.

80 to 125 psig at 100 CFM, oil and dirt free. 1 to 24 purge cycles per day, with a field selectable duration between 30 and 120seconds during which compressed air is released.

Line Size from AUTO-purge Panel to Flow Measuring Station or Probes.

Distance from AUTO-purge panelto flow measuring station air probe. Tube Size.

< 25' 1/2" S.S. tube25' - 50' 3/4" S.S. tube

> 50' 1.0" S.S. tube

Accumulator Tank (strongly recommended).Requires coalescing filter, pressure regulator, and check valve at the tank inlet.

120 gallons - All CA stations.120 gallons - Multiple VOLU-probes having a combined length greater than 10'.80 gallons - One or more VOLU-probes having a combined length less than 10'.

Line from Accumulator Tank to AUTO-purge Panel.

25' maximum length, " pipe (minimum). Recommend locating accumulator tank as close as possible to AUTO-purge panel.

Electrical Power Requirement.

None when used with an Air Monitor transmitter. (NOTE: This adds 36VA to the transmitter's power requirement.)24VAC, 36VA when not initiated by an Air Monitor transmitter.120VAC, 10 amp when an optional enclosure heater is installed.

Ambient Temperature.

40F-140F. For ranges above or below this ambient temperature, use of panel heater and/or cooler is required.

Purge Frequency.

Once/day minimum, once/hour maximum.

8.30.2

SUBMITTAL SHEET


SUB-M013, Rev. 7 (8/99)

AUTO-purge IIISEQUENCE OF OPERATIONS

IDENTIFICATION CODE

V-1,3 Pneumatically Piloted, 5-Way Valve, Static (low) PressureV-2,4 Pneumatically Piloted, 5-Way Valve, Total (high) PressureSV-1 Solenoid Operated 5-Way ValveSV-2 Solenoid Operated 3-Way ValveHV-1 Supply Air Shut Off ValvePI-1, 2 Gauge, Supply Air Pressure, 0-160 psigTB-2 Terminal Block, Purge Start Command from TransmitterPRV-1/FLTR-1 Pressure Regulator / Filter Assembly

SEQUENCE OF OPERATIONS

Automatic line purging interrupts airflow signal transmission atregular field selectable intervals and purges the station sensinglines with up to 125 psig air for short periods. This periodicpurging assists in maintaining the sensing orifices of the totaland static pressure manifolds in a clean, unobstructed condition.

A selectable timing sequence provided by the smart transmitteractivates solenoid valves (SV-1 and SV-2) which shuttles thetransmitter isolation valves (V3 and V4) and purge valves (V1and V2). A simultaneous output signal hold corresponding to thelast measured input is initiated by the transmitter and maintaineduntil the purge cycle is complete.

When valve V1/V3 and V2/V4 operate, the velocity pressure signallines (C and D) to the flow transmitter are isolated, and highpressure purge air AS1 is routed to the station (probes) sensinglines (A and B). The high pressure purge air cleans the flowsensing orifices of the flow station (probes) during the purgeduration.

At the end of the purge cycle the transmitter withdraws its purgesignal, de-energizing SV-1 and SV-2 and causing valves V3/V4and V1/V2 to reset after a short time delay to their normalposition, thereby reconnecting the process sensing lines to thetransmitter. After a short timed interval the transmitter signal holdis terminated and on-line signal processing resumes.

SCHEMATIC

8.32.2

SYSTEM DIAGRAMMATIC


In addition to being fabricated from durable, corrosion resistant materials, the Model CA Combustion Airflow Measuring Stationhas no moving components or parts that require periodic replacement or calibration. As such, the operation and maintenanceprocedures required for continued operation of the station are extremely limited.

The operating life of the Model CA Combustion Airflow Measuring Station is anticipated to be that of the operating life of theboiler or power facility.

OPERATION & MAINTENANCE

The Model CA Combustion Airflow Measuring Station hasa built-in air processing section (straightening andequalizing). This enables the station to be installed withoutthe long runs of straight ductwork upstream and downstreamof the station location (as required with the airfoils, otherprobe types, etc.). On new installations, this feature canpossibly reduce ductwork requirements by permitting thedesign to be condensed. Refer to Page 12 to obtain minimumrequirements for installation of the Model CA CombustionAirflow Measuring Stations.

The air processing section also assures that the automaticaveraging Pitot tube section will sense the duct flowaccurately, within 2 to 3% of the actual flow passing throughthe station and duct. Having no moving parts, the accuracyof the station is basic. It requires no field testing, verification,or periodic calibration.

The pressure drop, due to the presence of the station in theduct, is extremely low (refer to Page 1). At 2,000 fpm, theresistance to airflow of the Model CA Combustion AirflowMeasuring Station at 70 degrees is only 0.12 IN w.c. Thisis a small fraction of that of airfoils, orifices, etc., and ifproperly correlated back to the fan static requirements andselection, a considerable reduction in fan horsepower andsystem operating static can be made.

The presence of the air straightener/equalizer section alsobenefits the air pattern downstream of the station. By itselimination of rotational, turbulent airflow it can be of adecided benefit to the air distribution pattern. In applicationswhich are adjacent to the wind boxes (or ductwork take-offto them), this can be a decided help.

The multiple total and static pressure sensors of the ModelCA Combustion Airflow Measuring Station preclude theunlikely possibility of multiple sensors plugging due toairborne contaminants in the flow stream. However, shouldsome or many of the openings become blocked, the stationwill continue to average the remaining sensors to produce ausable and highly repeatable flow signal.

In particularly dirty applications or as a result of long termcontamination build-up, one or more of the individualsensors may become plugged. To correct for this problemwithout requiring internal cleaning or sensor manifoldremoval, all Model CA Combustion Airflow MeasuringStations can be equipped with sensor manifold cleanoutports accessible from outside the casing.

Manual cleaning can be accomplished by removing the endcaps on the sensing manifold(s) and cleaning them by meansof compressed air. Care must be exercised during manualcleaning with the fan system operating since accumulatedcontamination will tend to blow out of the ports of unitsinstalled on the pressure side of the fan.

Automatic cleaning can be accomplished using the AUTO-purge system, which consists of a series of valves, aprogrammable controller, and an interface with the signaltransmitter/controller contained in a NEMA 4 enclosure. Asource of high capacity 100 psi compressed air must beavailable at the installation site. The purge frequency isdetermined by the contamination level of the operatingsystem and is field set for a frequency range of once per dayto once per month.

10

SUBMITTAL SHEET


SUB-H014, Rev. 3 (3/97)

COMBUSTION AIR STATIONSMINIMUM INSTALLATION REQUIREMENTS

INSTALLATION CONSIDERATIONS. Installation factors to be considered when applying the Combustion Air Station are as follows:

Turbulent Airflow. The unique use of honeycomb airflow straightener in the Combustion Air Station will permit accurate flow measure-ment in the presence of moderate air turbulence. The distances from air turbulence producing fitt ings, transitions, etc.,shown below in the Minimum Requirements for Installation, are required to assure accurate Combustion Air Station operation.

Airborne Contaminants. Industrial applications containing airborne contaminants may require periodic manual or automatic cleaningusing compressed air applied via the signal fittings, and/or physical cleaning.

Direction of Airflow. The Combustion Air Stations will function only with the airflow passing through the air straightener section prior toentering the total and static pressure sensing section. To prevent improper installation, each Combustion Air Station is marked withan arrow indicating the required direction of airflow.

MINIMUM REQUIREMENTS FOR INSTALLATION. Note: Combustion Air Station locations shown are NOT ideal. They indicatethe minimum clearance required from air turbulence producing sources. Wherever possible, the Combustion Air Station should beinstalled where greater runs of straight duct (or clearances) than shown exist.

1X 1.5XX2

ROUND SWEEPELBOW

90 VANEDELBOW

2.5XX2

CENTRIFUGAL FANDISCHARGE

3X

FANS DAMPERS

TAKEOFFS

2.5X

1X

X2

2.5X

1.5XX2

SWEEP ELBOW90 UNVANED ELBOW

X24X

ELBOWS

DUCT TRANSITIONSX2

X2

X2

X2

TRANSITION ANGLE: < -15 TRANSITION ANGLE: < -15 TRANSITION ANGLE: < -15 TRANSITION ANGLE: < -15

( )Rectangular Duct: x = Circular Duct: x = Duct Diameter2 H x WH + W

3.6.1


Model CA Combustion Airflow Measuring Station

PHOTOGRAPHS

13

VELTRON DPT-plusMicroprocessor Based Ultra-Low RangePressure & Flow "Smart" Transmitter


The VELTRON DPT-plus transmitter is furnished with anautomatic zeroing circuit capable of electronically adjusting thetransmitter zero at predetermined time intervals while simul-taneously holding the transmitter output signal.

The automatic zeroing circuit eliminates all output signal drift dueto thermal, electronic or mechanical effects, as well as the need forinitial or periodic transmitter zeroing. For transmitters operatingin a moderately steady temperature location (thus no thermally

with Automatic Zeroing Circuit

VELTRON DPT-plus

Indication

Display. A backlit, graphical LCD providing three lines of datadisplay. Also used for programming.

Inputs/Outputs

Analog Inputs. Differential pressure (high and low), and 4-20mA,2-wire, internally or externally loop powered temperature signal.

Analog Outputs. Dual 4-20mA outputs, individually configurableas internally powered/non-isolated, or externally powered/isolated.

Digital Inputs. Digital contacts for AUTO-purge external start.

Digital Outputs. Dual Form A dry contacts rated for 3 amps at24VAC/VDC for optional HI/LO alarm; or dual Form A dry contactsfor AUTO-purge activation and acknowledgment.

Temperature Compensation Selection. Pushbutton selection oflinearized or non-linear temperature transmitter input for thefollowing temperature sensing types:

Type E 50 to 1750F 50 to 950C

Type T 50 to 750F 50 to 400C

Type J 50 to 2000F 50 to 1090C

Type K 50 to 2000F 50 to 1090C

RTD 50 to 1500F 50 to 815C

PowerPower Supply.Standard 24VAC (20-28VAC) or 24VDC (20-40VDC).Optional 120VAC (100-132VAC), via external transformer.

Power Consumption.Standard: 18VA at 24VAC; 13VA at 24VDC; 36VA at 120VAC.With AUTO-purge Management: 54VA at 24VAC; 48VA at

24VDC; 108VA at 120VAC.

Circuit Protection. Power input is fused and reverse polarityprotected.

Transmitter

Accuracy. 0.1% of Natural Span, including hysteresis,deadband, non-linearity, and non-repeatability.

Type. Differential pressure, flow, and mass flow.

Ranges. Natural Spans Bi-Polar Natural Spans0 to 25.00 IN w.c.0 to 10.00 IN w.c. 10.00 to 10.00 IN w.c.0 to 5.00 IN w.c. 5.00 to 5.00 IN w.c.0 to 2.00 IN w.c. 2.00 to 2.00 IN w.c.0 to 1.00 IN w.c. 1.00 to 1.00 IN w.c.0 to 0.50 IN w.c. 0.50 to 0.50 IN w.c.0 to 0.25 IN w.c. 0.25 to 0.25 IN w.c.0 to 0.10 IN w.c. 0.10 to 0.10 IN w.c.0 to 0.05 IN w.c. 0.05 to 0.05 IN w.c.

Span Rangeability. The calibrated span can be down ranged to40% of the Natural Span.

Stability. 0.5% of Natural Span for six months.

Temperature Effect. Zero. None; corrected by AUTO-zero.Span. 0.015% of Natural Span/F.

Mounting Position Effect. None; corrected through transmitterautomatic zeroing.

Span and Zero Adjustment. Digital, via internally locatedpushbuttons.

Low Pass Filtration. Response time to reach 98% of a stepchange is adjustable from 2.0 to 250.0 seconds.

Overpressure and Static Pressure Limit. 25 psig.

Automatic Zeroing.Accuracy. Within 0.1% of calibrated span.Frequency. Every 1 to 24 hours on 1 hour intervals.

Temperature Limits.20 to 180F Storage; +32 to 140F Operating.

Humidity Limits. 0-95% RH, non-condensing.

Performance Specifications

induced span drift), this automatic zeroing function essentiallyproduces a "self-calibrating" transmitter. The automatic zeroingcircuit will re-zero the transmitter to within 0.1% of its operatingspan; for a transmitter with a 0.02 IN w.c. operating span, thisrepresents a zeroing capability within 0.00002 IN w.c.

To permit manual calibration of the VELTRON DPT-plus, anelectronic switch is provided to permit manual positioning of thezeroing valve.


Ultra-Low Differential Pressure & Flow "Smart" Transmitter

Accuracy. The VELTRON DPT-plus is designed to maintain anaccuracy of 0.1% of Natural Span. For a span of 0 to 0.05 IN w.c.,this accuracy is equivalent to an output accuracy of 0.00005 INw.c. differential pressure or 0.90 FPM velocity.

Microprocessor Based Functionality. The VELTRON DPT-pluson-board microprocessor performs the functions of operatingparameter selection, transmitter configuration, input/output anddisplay signal scaling, and transducer calibration. Imbeddedsoftware performs span, flow, and 3-point "K" factor calculations.Input to the microprocessor is via pushbuttons.

Electronic Respanning. The VELTRON DPT-plus operating spancan be electronically selected anywhere between the Natural Spanand 40% of Natural Span, without having to perform recalibrationinvolving an external pressure source.

Air Density Correction. The VELTRON DPT-plus is capable ofaccepting a process temperature input to perform density correctionto volumetric or mass flow. Temperature input is a 4-20mA signalfrom a remote temperature transmitter; non-linear temperatureinputs can be linearized by the microprocessor. Temperature sensortype is software selectable from the following choices:Thermocouple types E, T, J, and K; or Platinum RTD.

High Turndown Ratio Operation. The VELTRON DPT-plus,with its high level of accuracy and automatic zeroing circuitry, canmaintain linear output signals on applications requiring velocityturndown of 10 to 1 (equal to a velocity pressure turndown of 100to 1).

Features

Continuous Display of Process. The VELTRON DPT-plus comesequipped with a multi-line, backlit, graphical LCD for use duringtransmitter configuration and calibration, and to display multiplemeasured processes in engineering units. The LCD provides oneline having 8 digits with double wide and double high characters,two 20 digit lines having standard size characters, and variousdescriptors for transmitter operating status.

Primary Signal Noise Filter. To eliminate background noise andpulsations from the flow signal, the VELTRON DPT-plus has auser selectable low pass digital filter.

AUTO-purge Management (optional). For "dirty air" applicationsrequiring the use of an AMC Power AUTO-purge system, theVELTRON DPT-plus provides the capabilities of establishing purgefrequency and duration while giving the user a choice of eitherinternally timed cycle frequency or externally triggered purgeinitiation. During the purge cycle all transmitter outputs aremaintained at their last value prior to the start of the purge cycle.

Hazardous Locations. The VELTRON DPT-plus is FactoryMutual and CSA approved for the following: Explosion Proof: Class 1, Division 1, Groups B, C, D. Dust Ignition Proof: Class II, III, Division 1, Groups E, F, G. Suitable for indoor and outdoor NEMA Type 4X hazardous

locations.

Enclosure. The VELTRON DPT-plus is packaged in a NEMA 4Xenclosure with standard industrial process connections.

High port 18 NPTfor pressure connection

14 NPT conduitconnections (2 places)

NEMA 4XField wiringend

Low port 18 NPTfor pressure connection

7.88(Max)

2

6.75(Max)

4.50(Max)

Standard LCDGraphical Display

Locknut

Calibration Port

Process Connections. Industry standard "-NPT ports on 2"centers on flanges. "-NPT ports on bottom of base.

Electrical Connections. Dual " conduit connections. Terminalstrip for field wiring and test points. External terminal strip withplug-in connectors.

O-Rings. BUNA N.

Physical Specifications

Electrical Enclosure. NEMA 4X aluminum body withNeoprene gaskets.

Paint. Polyurethane with epoxy primer.

Mounting. Flat and angle mounting brackets for 2" pipe.

Weight. 10.5 lbs.

125-025-00 (1/00)

VELTRON DPT-plus

Suggested Specification

The mass flow transmitter shall be capable of receiving flow signals(total and static pressure) from an airflow station or probe arrayequipped with a temperature sensing means, internally performdensity correction for the process temperature, and produceindividual outputs linear and scaled for standard air volume ormass flow, and temperature.

The mass flow transmitter shall contain an integral graphic LCDfor use during the configuration and calibration process, and becapable of indicating multiple process parameters (temperature,flow, dp, etc.) during normal operating mode. All transmitterparameter setting, zero and span calibration, and display scalingwill be performed digitally in the on-board microprocessor via inputpushbuttons.

The mass flow transmitter will be available in multiple naturalspans covering the range of 0.05 IN w.c. to 10.0 IN w.c. with an

accuracy of 0.1% of natural span. The transmitter shall be furnishedwith a transducer automatic zeroing circuit and be capable ofmaintaining linear output signals on applications requiring 10 to 1velocity (100 to 1 pressure) turndown. The transmitter shall becapable of having its operating span electronically selected withouthaving to perform recalibration involving an external pressuresource.

(Optional) The transmitter will provide the means of managing asystem for automatic high pressure purge of the airflow station orprobe array, with user selectable purge frequency and duration,while maintaining the last transmitter output during the purge cycle.

The mass flow transmitter shall be the VELTRON DPT-plus asmanufactured by AMC Power, Santa Rosa, California.

Mounting Configurations with Optional Brackets


Angle Mount to Horizontal Pipe Vertical Mount to Horizontal Pipe Mount to Horizontal Channel

Mount to Flat SurfaceVertical Mount to Vertical Pipe

Note: Mounting bracket kit includes-16 U-bolt, nuts, and washers for2" Schedule 40 pipe, plus 4 bolts andwashers to attach the transmitter to themounting bracket.

1 Copyright 2002 by ASME

Proceedings of IJPGC022002 International Joint Power Generation Conference

Phoenix, AZ, USA, June 24-26, 2002

IJPGC2002-26131

NOX REDUCTION OF A 165 MW WALL-FIRED BOILERUTILIZING AIR AND FUEL

FLOW MEASUREMENT AND CONTROL

Marion CherrySantee Cooper

Dave EarleyAMC Power

Combustion Technologies Corp.David SilzleAMC Power

ABSTRACTAs a result of increasingly stringent emissions limitations

being imposed on coal-fired power plants today, electric utilitiesare faced with having to make major compliance relatedmodifications to their existing power plants. While manyutilities have elected to implement expensive post-combustionNOx reduction programs on their largest generating units, in-furnace NOx reduction offers a less expensive alternativesuitable to any size boiler, to reduce NOx while also improvingoverall combustion. In-furnace NOx reduction strategies haveproven that, when used with other less expensive approaches(Overfire air, fuel switching, and/or SNCR), levels less than 0.15lb./MMBtu can be economically achieved. Furthermore, whenimplemented in conjunction with an expensive post-combustionSCR program, initial capital requirements and ongoing operatingcosts can be cut to save utilities millions of dollars.

For the purpose of developing a system-wide NOxreduction strategy, Santee Cooper, a southeastern U.S. utilityapplied pulverized coal flow and individual burner airflowmeasurement systems to Unit 3 at its Jefferies Station, a165MW, 16-burner front wall-fired boiler. The airflow

measurement system, in service for many years, applied a well-proven averaging Pitot tube technology to measure individualburner secondary airflow. The coal flow measurement systemutilized low energy microwaves to accurately measure coaldensity and coal velocity in individual coal pipes. Thecombination of these two systems provided the accuratemeasurements necessary for controlled manipulation ofindividual burner stoichiometries, giving the plant the ability toimprove burner combustion, yielding a reduction in NOx levelsapproaching 20%. Optimized burner combustion also resultedin a leveling of the excess O2 profile, which will enable the plantto pursue further reductions in excess air as well as stagedcombustion, thus allowing for further NOx reductions in thefuture.

How this program produced a significant NOx reduction willbe presented in detail in this paper. The paper will also discussthe effects on excess O2, opacity, and unburned carbon. Inaddition, this program will allow for future system-wide planningwith regard to possible SCR implementation.

Keywords: Coalflow, Combustion Optimization, NOxReduction.


REVIEW OF PF-FLO TECHNOLOGYTo obtain the mass flow of pulverized coal being

transported to a burner, one needs to know both theconcentration1 and the velocity of the coal in the burner pipe.The Pf-FLO system measures both the coal concentration andvelocity in each pipe, independent of both the measurementsperformed on the other pipes and the coal feeder information,resulting in coal velocity outputs for each pipe scaled in units offeet per second and mass flow outputs directly proportional tothe coal flow in each pipe.

Pf-FLO is a unique technology for online coal flowmeasurement in that it provides an accurate absolutemeasurement without need for in situ calibration. Other onlinecoal flow measurement systems require the use of fieldcalibration methods such as isokinetic sampling or rota-probing,which are known to be as inaccurate as 10%. The result ofutilizing these field calibration methods is a measurementsystem that can indicate balanced coal pipes when the actualmass flow distribution can vary as much as 20%. The Pf-FLOtechnology, requiring no calibration, produces an extremelyaccurate measurement of the coal flow to each burner.

Concentration

The concentration of the pulverized coal is measured usinglow power, low frequency microwaves, with each burners pipefunctioning as its own unique wave-guide. Since the coal flowin all pipes served by the same mill has the same fuel source,variables such as moisture content, fineness, coal type, etc., arethe same for all pipes. Therefore, the only variable pipe-per-pipeis the dielectric load, i.e., the concentration of the pulverized fuelin the section of pipe being measured. Starting with themeasured microwave transmission characteristic of each emptypipe, variations in the dielectric load caused by changing coalconcentration produce corresponding shifts in measurementfrequency, resulting in quantifiable values that are reported asthe absolute coal density in each pipe.

The concentration measurement is performed by twosensors aligned parallel to the longitudinal axis of the pipe; onefunctioning as the microwave transmitter, and the other as thereceiver, as shown in Figure 1. Located upstream anddownstream of the sensors are pairs of reflector rods, abrasionresistant, electrically conductive rods that prevent the

1 The term 'concentration' is meant as mass concentration or mass

density in this report.

microwave signal from leaving the measurement area and thenbeing reflected back in the form of microwave noise. The resultis a highly accurate measurement of coal concentrationregardless of particle distribution or the presence of roping.

Figure 1 Standard Sensor and Rod Arrangement

Velocity

The velocity of the pulverized coal is measured by thecross-correlation method, which is conceptually depicted inFigure 2. The same two sensors used for the measurement ofcoal concentration have a known separation distance.Stochastic signals created on the pair of sensors by the chargedcoal particles are nearly identical, but shifted by the time thepulverized coal needs to get from one sensor to the other. Asthe distance between the sensors is fixed, the velocity of thepulverized coal in the pipe can be accurately calculated.

Figure 2 Cross-Correlation Configuration


IBAM (INDIVIDUAL BURNER AIRFLOWMEASUREMENT) FLOW TECHNOLOGY

The flow measuring technology used for the IBAMs isbased upon AMC Powers VOLU-probe design (U.S. Patent4,559,835). The VOLU-probe operates on a Fechheimer-Pitotderivative of the multi-point, self-averaging pitot principle tomeasure the total and static pressure components of airflow, andrequires very little straight duct run to maintain an accurate flowsignal. Total pressure sensing ports, with chamfered entrancesto greatly lessen entrance effects, are located on the leadingsurface of the VOLU-probe to sense the impact pressure (Pt ofthe approaching airstream, refer to Figure 3). Fechheimer staticpressure sensing ports, positioned at designated angles offsetfrom the flow normal vector, minimize the error-inducing effect

of directional, non-normal airflow. As the flow direction veersfrom normal (Figure 4), one static sensor is exposed to a higherpressure (Ps + part of Pt) while the other is exposed to a lowerpressure (Ps - part of Pt). For angular flow where a = 30 offsetfrom normal, these pressures are offsetting and the pressuresensed is the true static pressure. It is this unique design of theoffset static pressure and the chamfered total pressure sensors(Figures 3 and 4) that makes the VOLU-probe (and IBAM)relatively insensitive to approaching multi-directional, rotatingairflow with yaw and pitch of up to 30 from normal, therebyassuring the accurate measurement of the sensed airflow ratewithout the presence of upstream airflow straighteners.

Figure 3

Figure 4


APPLICATION OF TECHNOLOGIES

Burner Airflow Measurement

In 1998, new Babcock Borsig Power (BBP) CCV II burnersas shown in Figure 5 were installed on Units 3 and 4 at SanteeCoopers Jefferies Station. As part of the low NOx burnerupgrade, IBAM probes were installed in the inner (secondary)and outer (tertiary) burner registers, as shown in Figure 6.Normally, a pair of IBAM probes are utilized in each burner airzone to achieve optimum measurement accuracy, but since

initial burner tuning was the extent of the original intended usefor the IBAM probes at this installation, only a single probe perair zone was installed by BBP. The separate probes forsecondary and tertiary airflow were individually connected togauges with a range of 0 to 3 inches w.c. to provide localindication of the measured differential pressures.

Figure 5 CCV II Burner



Burner Airflow Measurement (cont)

The IBAM probes were installed without automaticblowback (purge) systems typically used to keep the probesclean, and only limited manual blowbacks were performedduring the two-year period following the installation of the CCVII burners. Since flyash and airborne particulate were present inthe windbox, all probes were suspected to be experiencing atleast partial pluggage, with locations D2Secondary Air (SA),D2Tertiary Air (TA), C1TA, C2SA, C3-SA and C4-SAindicating near complete pluggage.

In July of 2001 during a boiler outage, all IBAMs weresubjected to a series of high-pressure purges followed by avisual inspection through the furnace side of the burners. Allsensing holes appeared to have been cleared. When the boilerwent back on line, the measured differential pressures wereelevated back to expected levels, but past experience with thisdegree of pluggage in probes that have not been maintainedover long periods of time often requires removal of the probes

for physical cleaning of the probe interior, or probe replacementto regain 100% of design performance. For IBAM probes usedfor frequent or on-line measurement, the use of an automatedblowback system would prevent this condition from everoccurring. Prior to the start of any subsequent test sessions,the IBAMs were again subjected to multiple high-pressurepurges to clear any accumulated flyash and particulate.

The IBAM differential pressure signals were converted intomass flow units of lbs/hr, using the cross-sectional area factorfor each register and a density value for the windbox air basedon the average windbox static pressure and temperature.Without the use of individual mass flow transmitters capable ofperforming continuous density compensation, it isacknowledged that the cumulative effect of partial probepluggage plus temperature and/or pressure variations within thewindbox could introduce some error into the calculation of airmass flow for the individual burners.

Figure 6 Sectional View of Burner



Burner Coal Flow Measurement

The Pf-FLO coal flow measurement system was installed onUnit 3 coal pipes. Unit 3 has four Atrita mills equipped withdrum feeders. Each mill feeds a separate burner row of fourburners through four individual coal pipes on this single wall-fired boiler. The Pf-FLO sensor arrays were installed in verticalor near vertical sections of coal pipe approximately 12 feet from

the mill outlets, as shown in Figure 7. After the standard systemcommissioning procedure, the Pf-FLO system began providingcontinuous measurement of coal velocity in units of feet persecond and mass flow in absolute units (a.u.) for each of the 16pipes. A general burner arrangement is shown in Figure 8below.

Figure 7 Pf-FLO Sensor Installation, Unit 3

Figure 8 Burner Arrangement, Unit 3


VALIDATION OF TECHNOLOGY

For the purposes of demonstrating the capabilities of theinstrumentation and becoming familiar with the boilersresponse to changes in feeder rate, secondary air adjustments,etc., a series of preliminary measurements and burneradjustments were performed before all burner settings werereturned back to normal operating positions in order to obtainbaseline data.

In addition to the measured airflow and coal flow, the boilerback-pass contains an excess oxygen grid consisting of four O2probes. The O2 probes are positioned to be representative ofeach column of burners. In the presented data, the O2measurement for each probe is shown above its correspondingcolumn of burners.

The following burner variables and data points wererecorded for each burner during each test session:

Secondary air swirl angle Tertiary air swirl angle Burner inlet damper (shroud) positionSecondary air IBAM DPTertiary air IBAM DPCoal mass flow in a.u.

Other boiler data collected during each test session were:

Four O2 probe measurements Primary air signals for each millFeeder signals for each millWindbox static pressureWindbox temperatureUnit MW load


VALIDATION OF TECHNOLOGY (cont)

Test Session 1 Flattening the O2 Profile

Test Session 1 was conducted on July 24-25, 2001. Prior tothe collection of baseline data, the ash hoppers were cleared.At the baseline test load condition, the hoppers collected ashfor one full hour. Samples of the accumulated ash were analyzedin the station lab and used as the baseline unburned carbon(UBC)data. After all subsequent burner and/or mill adjustments weremade to improve combustion, the ash hoppers were againcleaned out, and new ash was collected for an hour beforesamples were extracted for analysis.

The baseline data can be seen in Table 1 in the Appendix.Shown below in Table 2 is the baseline data after the IBAMdifferential pressure values were converted to air mass flow. Inaddition, a ratio of the air-to-fuel was calculated for each burnerto facilitate relative burner-to-burner comparison and pinpointboth rich and lean burners. Note that the air-to-fuel ratios usethe Pf-FLO mass flow measurement in a.u. (absolute units)rather than the normal lbs/hr.

.

O2 Grid: 2.40 % 3.65 % 4.66 % `4.59 %

A1 A2 A3 A4

Air Flow: 84078 lb/hr 89280 lb/hr 83115 lb/hr 80965 lb/hrFuel Flow: 6690 a.u. 5170 a.u. 6560 a.u. 7015 a.u.Air / Fuel 12.57 17.27 12.67 11.54

D1 D2 D3 D4


C1 C2 C3 C4


B1 B2 B3 B4


Date: 7/24/01Time: 10:30 PMLoad: 165 MW

Table 2 Baseline Data



Test Session 1 Flattening the O2 Profile (cont)

For Test Session 1, an objective of achieving an averageair-to-fuel ratio (relative lbs/hr to a.u.) of approximately 15 wasestablished. The burners that deviated the most from thataverage had their SA shroud position adjusted to allow for moreor less airflow, bringing the air-to-fuel ratio closer to the targetof 15. In addition to the SA shroud position changes, all of thedrum feeder rates and the PA on Mill B were adjusted to obtaina better balanced fuel distribution to each row of burners. Thefollowing adjustments were made in several steps:

Bias PA on Mill B down 3%Bias feeder speed on Mills A and B down 5%, Mills Cand D up 5%Close shrouds 10% on Burners A2 and D2, 15% onBurners C2 and D4, and 25% on Burner C4Open shrouds 10% on Burners A4 and B4, 15% onBurners B2 and B3, and 25% on Burner B1

All resulting changes in airflow and coal flow associatedwith the shroud and burner adjustments were measured by theIBAM and Pf-FLO systems. The data can be seen in Table 3 inthe Appendix. Shown below in Table 4 is the data after theIBAM differential pressure values were converted to air massflow and the burner SA to fuel ratios were calculated for eachburner.

Due to the windbox configuration and the SA points ofentrance into the windbox, it was difficult to get sufficient air toall of the burners, even with shrouds 100% open. Similarly, thecoal flow to a few of the burners could not be offset withenough air to obtain the targeted 14-16 range for air-to-fuelratios. Without having the ability to redistribute the coal flowamong the burners supplied by the same mill, neither theoptimization of fuel distribution to each burner nor the desiredburner stoichiometry could be obtained. These limitations,when combined with the fact that the O2 profile had beendramatically improved, led to a decision to halt makingadjustments to the fuel and air delivery, and move on to the NOxreduction phase of the project.

O2 Grid: 3.92 % 4.15 % 4.26 % 4.05 %

A1 A2 A3 A4


D1 D2 D3 D4


C1 C2 C3 C4


B1 B2 B3 B4


Date: 7/25/01Time: 1:30 AMLoad: 165 MW

Table 4 Results Data


VALIDATION OF TECHNOLOGY (cont)

Test Session 2 Reducing Excess O2

Test Session 2 was conducted September 12, 2001. Havingdemonstrated in Test Session 1 that the IBAM and Pf-FLOmeasurement systems were capable of being used to optimizecombustion and flatten the boilers O2 profile, the objective ofTest Session 2 was NOx reduction, since a flattened O2 profilepermits the safe reduction of excess air entering the boiler, and areduction in excess air generally produces reduced NOxemissions.

Unit 3 was first increased to near full load (to 162 MW) andheld at that load for the duration of the session, other than ashort duration reduction to 158 MW. The NOx levels from theCEMS were recorded on one-minute intervals. Similarly,baseline airflow, coal flow, and boiler parameters were recordedand can be seen in Table 5 in the Appendix. The derived airflowand air-to-fuel ratios are shown below in Table 6.

O2 Grid: 3.80 % 4.52 % 5.20 % 4.42 % 4.48 %

A1 A2 A3 A4 A TOTALAir Flow: 105643 lb/hr 94368 lb/hr 93648 lb/hr 90460 lb/hr 384119 lb/hr

Fuel Flow: 8290 a.u. 6080 a.u. 8050 a.u. 5660 a.u. 28080 a.u.Air / Fuel 12.74 15.52 11.63 15.98 13.67

PA Signal 4060Feeder Signal 46960

D1 D2 D3 D4 D TOTALAir Flow: 87485 lb/hr 76349 lb/hr 85601 lb/hr 89139 lb/hr 338574 lb/hr



C1 C2 C3 C4 C TOTALAir Flow: 89076 lb/hr 104106 lb/hr 84707 lb/hr 92792 lb/hr 370681 lb/hr



B1 B2 B3 B4 B TOTALAir Flow: 64880 lb/hr 73191 lb/hr 66797 lb/hr 77788 lb/hr 282656 lb/hr



Column Average Air Flow 347085 lb/hr 348015 lb/hr 330753 lb/hr 350179 lb/hr 1376032 lb/hrColumn Average Fuel Flow 25950 a.u. 22090 a.u. 25450 a.u. 18370 a.u. 91860 a.u.Column Average Air / Fuel 13.38 15.75 13.00 19.06 14.97

Date: 9/12/01Time: 10:00 AMLoad 162 MW



Test Session 2 Reducing Excess O2 (cont)

Based upon the results of Test Session 1, burner shroudpositions and feeder rates were adjusted with two purposes inmind; to maintain the flattened O2 profile previously achieved,and to obtain an element of fuel staging. The total fuel to eachrow of burners was adjusted to allow more fuel to be introducedto the boiler via the bottom row of burners and less fuel via thetop row of burners. The following adjustments were made:

Bias feeder speed on Mill A down 12%, Mill C up 12%Close shrouds 10% on Burner D2, 15% on Burner A2, and20% on Burners C2 and D4Open shrouds 10% on Burners A1 and C1, 15% onBurners B1 and D1, 20% on Burner C4 and 30% on BurnerB3.

With the target burner stoichiometry achieved and the O2stratification minimized, the final step taken was to reduce

excess air by reducing the FD Fan output, thus lowering totalburner SA. A safe series of incremental adjustments were madeand overall excess O2 was reduced. Baseline airflow, coal flow,and boiler parameters were recorded and can be seen in Table 7in the Appendix. The derived airflow and air-to-fuel ratios areshown below in Table 8. Testing was concluded atapproximately 4:45 p.m., and the

air monitoring combustion air power boilers

Documents

airflow measuring concept

primary airflow pressurized

na paper

primary airflow raymond

na brochure

na drawing

air fuel flow measurement

pulverized fuel flow