36C10F18R0679-A00006007.pdf

INSTRUCTION AND OPERATION MANUAL

FOR GAS AND LIGHT OIL FUEL SYSTEMS

MANUFACTURED BY JOHN ZINK COMPANY, L.L.C.

PRINCIPLES OF OPERATION

The model RMB burner is designed to produce ultra low NOx emissions levels firing gas fuels. The patented burner design utilizes rapid mixing of fuel and air at the burner outlet to suppress the formation of prompt NOx and uses induced flue gas recirculation to suppress thermal NOx formation. The burner is capable of operating with NOx emissions as low as sub-9ppm, while providing stable and reliable combustion.

*Covered by one or more of the following patents:

U.S. Patent Numbers 5407347; 5470224; 4785680; 4932274. CA Patent Number 1279632. 09 06-1884

BURNER MUST BE INSTALLED, MAINTAINED, AND OPERATED BY TRAINED PERSONNEL. DO NOT

ATTEMPT TO OPERATE THE BURNER WITHOUT FIRST FAMILIARIZING YOURSELF WITH THESE

OPERATING INSTRUCTIONS! IMPROPER INSTALLATION, OPERATION, OR MAINTENANCE OF

THE EQUIPMENT MAY RESULT IN INJURY TO PERSONS, LOSS OF LIFE AND DAMAGE TO THE

EQUIPMENT.

THIS MANUAL IS PROVIDED TO SUPPLY GENERAL INFORMATION ON THE

OPERATION, AND MAINTENANCE OF THIS BURNER SYSTEM. HOWEVER, NOT

EVERY CONTINGENCY OF INSTALLATION, OPERATION, AND MAINTENANCE CAN

BE COVERED IN ANY MANUAL. THEREFORE, THE OWNER’S OPERATING AND

MAINTENANCE PERSONNEL SHOULD ALSO BE GUIDED BY GENERALLY ACCEPTED

INDUSTRY PRACTICE IN THE INSTALLATION, OPERATION, AND MAINTENANCE OF

THIS BURNER SYSTEM.

RMB UltraTM* and FRMBTM* ULTRA LOW NOx BURNER

NOTE:

WARNING!

TABLE OF CONTENTS

PART I MINIMUM INSTALLATION INSPECTION CHECKLIST

PART II GENERAL

PART III BURNER FAMILIARIZATION AND PRELIMINARY INSPECTION . . . 7

PART IV SYSTEM DESCRIPTION

General Burner Operation Principles of NOx Formation and Control Gas Piping Information Oil System Purging Oil Piping Information

PART V COMBUSTION SYSTEM ADJUSTMENTS

Air Inlet Louver Box Gas Pilot Ignitor Butterfly Gas Valve Gas Pressure Regulators Gas Pressure Switches Oil Drawer Assembly Oil Metering Valve Oil Supply Pressure Regulator Valve Low Oil Pressure Switch Characterized Linkage Air Flow Switch (Diaphragm)

PART VI BURNER START-UP

Flame Safeguard Installation Identification of Controls Ignitor Flame Scanner Air Positioners, Dampers and Linkage Dual Fuel Burners Start-up Settings of Burner Controls Gas Firing Tuning on Gas Automatic Operation on Gas Flame Considerations for Gas Firing Low and High Gas Pressure Switches Final O2 and CO Analysis on Gas Motor Running Current and Voltage Check Burner Safety Check on Gas Normal Operation on Gas Oil Firing Tuning on Oil Removal of oil gun for extended gas firing Flame Considerations for Oil Firing Low Oil Pressure Switch Final O2, CO and Smoke Analysis on Oil Cleaning of Oil System Components after Start-up Burner Safety Check on Oil Normal Operation on Oil

PART VII TROUBLE SHOOTING

Gas Ignitor Main Flame Ignition Failure Gas Firing Oil Firing

PART VIII SAFETY MEASURES

PART IX MAINTENANCE DETAILS AND SCHEDULE

Periodic Testing Recommended Check List

PART X SUPPLEMENTARY DATA

WARNING!

If you smell gas:

1. Open windows.

2. Don’t touch electrical switches.

3. Extinguish any open flame.

4. EVACUATE people from building.

5. Immediately call the gas supplier.

The use and storage of gasoline or other flammable liquids and vapors in open containers in the vicinity of this appliance is hazardous.

In accordance with OSHA standard 1910.147, all equipment, machines and processes shall be locked out prior to servicing.

Do NOT use TEFLON TAPE or compounds with TEFLON content as an oil or gas pipe sealant. TEFLON can cause valves to fail creating a SAFETY HAZARD. Warranties are nullified and liability rests solely with the installer when evidence of TEFLON is found.

If not installed, vented, operated and maintained in accordance with the manufacturer’s instructions, this product could expose you to substances in fuel or from fuel combustion which can cause death or serious illness and which are known to the State of California to cause cancer, birth defects or other reproductive harm.

Improper servicing of this equipment may create a potential hazard to equipment and operators.

BURNER COMMISSIONING AND SERVICING MUST

BE DONE ONLY BY FULLY TRAINED AND QUALIFIED

PERSONNEL.

Before disconnecting or opening up a fuel line and before cleaning or replacing parts of any kind:

■ Turn OFF the manual fuel shutoff valves including pilot gas cock, if applicable. If a multiple fuel burner, shut OFF all fuels.

■ Turn OFF all electrical disconnects to the burner and any other equipment or systems electrically interlocked with the burner.

GENERAL

❏ Is burner installed in accordance with applicable installation drawings?

❏ If a refractory combustion chamber is part of the installation, is it completely dry, cured, and ready for firing at full boiler input?

❏ Has the proper electrical voltage been connected to the burner control cabinet as shown on the burner material list?

❏ Has the burner wiring been checked for completeness and accuracy? Have 3-phase motors been properly wired and checked for correct rotation?

❏ Are the boiler mounted limit controls such as low water cutoffs, high limit controls, operating controls, modulating controls, etc., properly installed and wired?

❏ Are the boiler controls the right type and range for the installation?

❏ Is the boiler water supply, including feed pumps, properly connected and is boiler filled with water?

❏ Is sufficient load connected to the boiler so that it can be fired continuously at full rating?

❏ If boiler load is not connected, can steam be wasted so that boiler can be fired continuously at full rating without endangering personnel or equipment?

❏ If the installation is a hot water boiler, have the circulating pumps been completely installed, wired, and tested to assure proper operation so that the burner can be fired continuously at full rating?

❏ For new boiler installations, has the boiler been boiled out in accordance with the boiler manufacturer’s instructions?

❏ Have the boiler breeching connections to the stack been completed and are they open and unobstructed?

❏ Is draft control equipment required and, if so, installed?

❏ Have adequate provisions for combustion air been installed?

❏ Have the persons listed below been notified of the burner start-up date?

❏ Owner’s Representative

❏ Mechanical Contractor’s Representative

❏ Electrical Contractor’s Representative

❏ Service Organization’s Representative

❏ Boiler Manufacturer’s Representative

❏ Is all specified auxiliary equipment mounted and wired? This may include outdoor temperature controls, oil flow switches, space thermostats, water flow switches, motorized combustion air louvers, etc.

PART I

MINIMUM INSTALLATION INSPECTION CHECKLIST

GAS FIRING

❏ Are all gas train components installed and have they been properly selected, sized and assembled?

❏ Have properly sized vent lines been installed on all gas train components which require venting? This includes such items as pressure regulators, normally open vent valves, diaphragm valves, low and high gas pressure switches, etc.

❏ Have gas train piping and components been tested and proven gas tight?

❏ Have the gas lines been purged?

❏ Is the proper gas pressure available at the inlet to the controls which meets the requirement shown on the burner material list?

OIL FIRING

❏ Is the oil tank installed and filled with the proper type and grade of fuel oil as required by the burner material list?

❏ Is the proper oil pressure, temperature and viscosity available at the inlet to the controls which meets the requirements shown on the burner material list and/or oil system sheet?

❏ Have oil supply and return lines been properly sized to meet the maximum pumping capacity of the pump and has the system been purged and proven leak proof?

SIGNATURE OF INSPECTOR(S)

Name: ______________________________________________________ Date: ______________________

Name: ______________________________________________________ Date: ______________________

Name: ______________________________________________________ Date: ______________________

PART I: MINIMUM INSTALLATION INSPECTION CHECKLIST CONTINUED

■ Starting a burner is an event which normally culminates the efforts of several different contractors, manufacturers, utility and engineering concerns, sales and factory representatives, and others.

■ In order for the burner to operate safely and meet its design capabilities, the interfacing fuel, air, electrical, exhaust and plant heating control systems must be properly sized, selected, installed and tested.

Additionally, all conditions must be such that the heat generated by the burner can be safely used or wasted without endangering personnel or equipment.

■ It shall be the policy of John Zink Company, L.L.C. that no responsibility is assumed by the company nor any of its employees for any liability or damages caused by an inoperable, inadequate or unsafe burner condition which is the result, either directly or indirectly, of any of the improper or inadequate conditions described above.

■ To insure that a safe and satisfactory installation has been made, a pre-start inspection is necessary. This inspection must be performed by an individual who is thoroughly familiar with all aspects of proper boiler/burner installation and how it interfaces with overall plant operation.

■ Part I of this bulletin sets forth major inspection items that must be considered.

■ The results of this inspection will often times identify corrections that must be made prior to start-up as well as point out potential or long range problems in plant operation if corrections are not made.

■ Burner start-up is a serious matter and should not be viewed as a time for “crowd gathering” by unconcerned, uninformed or unauthorized personnel. The number of persons present should be held to an absolute minimum.

■ Instruction of operating and other concerned personnel should be done after the burner has been successfully fired and adjusted by a qualified service agency or factory start-up specialist.

NOTE

PART II

GENERAL

Installation requirements and instructions should always be covered in appropriate engineering drawings and specifications which detail the applicable building codes, etc. Information contained herein is to be used as a guide ONLY and not as the final authority.

NOTE

This inspection should be performed before the burner start-up specialist is called in. An incomplete or inadequate installation may require additional time and effort by start-up personnel and cause an untimely and costly delay.

BURNER FAMILIARIZATION

Study the following illustrations taking special note of the PART NAMES as shown in the call-outs.

Variations between systems are commonplace due to the many differences in job conditions and agency requirements.

This manual contains information applicable to a typical fuel system arrangement and is not intended to be representative of any specific agency or code criteria.

PRELIMINARY INSPECTION

The burner should be visually checked for damage and loose components as these conditions can occur during shipment, through improper handling, by tampering or through improper care and storage at the job site.

CHECK FOR:

❏ Obvious damage to housing, air inlet, and components mounted thereon.

❏ Tightness of fasteners, tube fittings, plugs, etc.

❏ Tightness of electrical terminals and connections.

❏ Tightness of adjustment mechanisms such as ball-joint swivel connectors and control arms.

❏ Accumulations of oil, dust, dirt, water or other foreign matter on, in, or near the burner.

PART III

BURNER FAMILIARIZATION AND PRELIMINARY INSPECTION

PART II: BURNER FAMILIARIZATION AND PRELIMINARY INSPECTION

FRMB (Integral Fan)

Lifting lug

Air servoFGR connection

Fan housing

Ignition transformer

Fan motor

Gas butterfly valve

Combustion head

Air inlet louver boxAir-FGR mixing box

Center-fire gas balancing valve

Air flow switch

RMB Ultra (Remote Fan)

Windbox

Gas servo

Combustion air duct connection

Gas butterfly valve

Ignition transformer

Pilot gas train

Combustion head

Center-fire gas balancing valve

Burner gas pressure gauge

See Combustion Air Fan Drawings and Instructions included with this manual for remote fan assembly details.

Burner Front Views (RMB Ultra and FRMB)

Outer refractory quarl

Inner refractory

Center-fire gas

Scanner port

Sight port

Gas pilot

Center-fire gas

Scanner port

Gas pilot

Site port

Swirl vanes

Inner refractory

Swirl vanes

Oil gun

Outer refractory quarl

Gas and Oil Burner

Gas Only Burner jmatecki Line jmatecki Line

GENERAL

The following data is pertinent to the burner start-up and should be carefully studied before any attempt to start the burner is made. This material is a part of the instructions manual which accompanies the burner.

■ Burner Material List

■ Burner Wiring Diagram

■ Flame Safeguard Bulletin

■ Gas System Schematic (Diagram 35-000204-40)

Air System Schematic (Diagram 35-000205-40 or Diagram 35-000212-40)

■ Combustion Air Fan Drawings and Instructions (if applicable)

■ Oil System Sheet (if applicable)

(1-gen-80.8 for air atomized oil systems or 1-gen-80.9 for steam atomized oil systems)

■ Manufacturer’s Data Sheets on Controls, Valves, Regulators, etc.

The above cited manual is “One of a Kind” in that it contains material covering your specific burner. To replace it, considerable time, special handling, and significant costs are involved. Accordingly, it should be handled with care and kept in a location free of dust and moisture.

BURNER OPERATION

The Rapid Mix Burner (RMB) is a state-of-the-art low NOx burner developed to meet current and future regulatory emissions requirements.

Combustion air is premixed with recirculated flue gas and then rapidly mixed with gaseous fuel just upstream of the burner throat. The high degree of mixing combined with the advanced swirl burner geometry, achieves optimal combustion efficiency, low emissions, and a compact, stable flame. The burner’s basic layout and principle of operation is shown in Figure 4-1.

It is important to note that once your burner is set up, tuned, and the controls are locked, the correct balance of air and FGR has been achieved. Changing the tuning parameters by untrained personnel can result in pulsation, flame instability, high emissions, or explosions. Although the interchangeability of air and FGR gives the burner added flexibility in controlling NOx emissions, it also means that equally careful control must be maintained over the FGR and excess air level both during the steady state and transient conditions.

Because of the rapid and complete mixing of the fuel and the combustion air, NOx emissions can be effectively controlled using recirculated flue gases (FGR) and excess air levels.

By designing in the proper FGR and excess air rate, NOx emissions can be reduced to extremely low levels. Because the burner operates with near ideal mixing, products of incomplete combustion such as CO and unburned hydrocarbons are virtually eliminated up to a 4:1 turndown range.

PART IV

SYSTEM DESCRIPTION

Do NOT use Teflon tape as an oil or gas pipe sealant. Teflon tape can cause valves to fail creating a safety hazard. Warranties are nullified and liability rests solely with the installer when Teflon tape is used. Use a pipe joint compound rather than Teflon tape.

WARNING!

Please read through these instructions and refer to the separate data sheets before attempting to start the burner.

NOTE

Do NOT operate burner with FGR system disconnected or non functioning.

As shown in Figure 4-1, the RMB can be supplied as a dual fuel burner and fired on oil or other liquids. NOx control with oil fuels is obtained by adjusting the liquid spray angle and number of injection holes to delay fuel and air mixing and the use of FGR to control thermal NOx. Simultaneous firing of liquid and gas fuels is not permitted at any time.

The RMB offers simplicity of operation combined with superior performance, with the following main feature and advantages.

■ Ultra-low NOx levels (as low as sub-9 ppm @ 3% O2), using gaseous fuels;

■ CO and hydrocarbon emissions typically less than 1 ppm;

■ Compact flame minimizing the potential for flame impingement.

PRINCIPLES OF NOx FORMATION

AND CONTROL

NOx emissions are one of the primary pollutant concerns from fossil-fuel fired boilers. The formation of NOx during the combustion of fossil fuels has been associated with three distinct mechanisms, generally referred to as “Thermal NOx,” “Fuel NOx,” and “Prompt NOx.” An understanding of the mechanisms involved in the formation of NOx can be used to control NOx emissions through combustion modifications. Combustion modifications can be implemented via the design of the combustion system and/or the selection of specific operating conditions. An understanding of the mechanisms of Thermal, Prompt, and Fuel NOx formation has also been used to develop correlations of NOx emissions for various burner types, boiler designs and different fuels. These correlations allow projections of NOx emissions to be developed for a given combustion system.

PART IV: SYSTEM DESCRIPTION CONTINUED

Figure 4-1

Thermal NOx refers to the NOx generated by the high temperature reaction of atmospheric nitrogen and oxygen present in the combustion air. The reaction rate is highly dependent on temperature, since high energy is required to break the nitrogen molecule’s chemical bond: Thermal NOx formation is primarily controlled by temperature and by residence time of the nitrogen in the flame zone. The formation of thermal NOx is dependent to a lesser extent on the availability of oxygen in the flame zone. Because Thermal NOx formation is so highly dependent on temperature, the flame environment and the furnace geometry can dramatically affect its formation. Heat reflected back into the flame from refractory covered walls, or high heat release rates in the boiler (BTU’s per cubic foot of furnace volume), will both tend to increase thermal NOx formation.

Fuel NOx is formed by the oxidation of organically bound nitrogen in the fuel during combustion. Fuel NOx formation is less sensitive to flame temperature than thermal NOx (since less energy is required to free up the nitrogen atom), but is strongly influenced by oxygen availability. Since Fuel NOx formation is directly related to the content of organically bound nitrogen in the fuel, the higher the fuel nitrogen content, the higher the fuel NOx generated. For combustion of fuel oil, both Fuel NOx and Thermal NOx mechanisms are important. For natural gas firing, however, only Thermal NOx and Prompt NOx are formed in any significant quantities, since natural gas contains negligible amounts of organic nitrogen. Some unusual gaseous fuels can contain chemically bound nitrogen, such as ammonia, that will form Fuel NOx.

Prompt NOx is formed during a two step process as a result of local sub-stoichiometric conditions within the flame.

Conventional low NOx burners lower thermal NOx, in part, through creating local sub-stoichiometric zones within the flame, this is often referred to as fuel staging or air staging. Sub-stoichiometric combustion results in the formation of CO, OH, and other radicals including HCN. HCN and similar products of incomplete combustion include Nitrogen as part of the molecule.

These compounds are later burned to completion as the air mixes with the flame; unfortunately, they readily burn to NOx.

Concisely put, the flame forms fuel bound nitrogen within the flame and converts it to NOx. Prompt NOx forms at very low concentrations in the 10 to 20 ppm range. It is important because it prevents conventional low NOx burners from ever reaching NOx levels less than 10 ppm. The RMB burner eliminates the formation of prompt NOx because the rapid mixing does not allow sub-stoichiometric conditions to form.

Combustion techniques that are employed in this burner to reduce NOx emissions include:

(1) Rapid Mixing

(2) Flame temperature reduction through the use of flue gas recirculation

Rapid Mixing is a NOx reduction technique that is described fully under prompt NOx immediately preceding this section.

Thermal NOx can be controlled by reducing the overall flame temperature. One effective technique is the use of flue gas recirculation (FGR). The addition of flue gas from the boiler or economizer exit to the combustion air acts to decrease the flame temperature and lower the local oxygen concentration. FGR can have a relatively minor impact on boiler performance if properly designed, although the increased fan power required for the recirculation must be considered. FGR can also cause unstable flames if used improperly.

The RMB burner is stable with 40% FGR or more. Under certain circumstances, this can be increased. Other effective means of reducing the flame temperature are lowering the combustion air temperature and lowering the FGR temperature. Both methods directly reduce the flame temperature.

GAS PIPING INFORMATION – The “E2” gas system is used for modulation firing, and is provided in a single point positioning linkage configuration and a linkageless parallel positioning configuration. It is used on RMB burners with 5,250 MBH to 105,000 MBH capacity and is used in conjunction with the “F8” and “F9” oil systems for combination gas-oil models.

DESCRIPTION

The “E2” linkage gas system uses motorized gas valves and a single modulating motor to provide a low fire to high fire gas flow and simultaneously regulate the combustion air available to the burner. Gas pressure is adjusted and maintained by a pressure regulator, which may be integrated with the motorized gas valves in some cases. Head or orifice pressure is varied by a butterfly metering valve linked to the modulating motor. The gas butterfly metering valve is opened for high fire and gas is delivered to the orifices at the pressure setting of the pressure regulator. The air louvers are also linked to the modulating motor, thus combustion air is increased proportionately as the orifice pressure increases.

At start-up the linkages are adjusted to provide the proper air-fuel ratio across the burner operating range.

The “E2” linkageless gas system uses motorized gas valves and a servo motor to provide a low fire to high fire gas flow.

A separate servo motor is connected to the air louvers and simultaneously regulates the combustion air available to the burner. Gas pressure is adjusted and maintained by a pressure regulator, which may be integrated with the motorized gas valves in some cases. Head or orifice pressure is varied by a butterfly metering valve. The gas butterfly metering valve is opened for high fire and gas is delivered to the orifices at the pressure setting of the pressure regulator. The air louvers are controlled in parallel by the air-fuel ratio controller, thus combustion air is increased proportionately as the orifice pressure increases. At start-up the fuel-air control curve is characterized to provide the proper air-fuel ratio across the burner operating range.

Flue gas recirculation (FGR) is piped from the exhaust of the boiler to a mixing box attached to the inlet of the combustion air fan. Suction from the fan provides the motive force to draw FGR to the fan, where it is then mixed with the combustion air. An FGR damper with its own modulating motor, or servo, controls the amount of FGR delivered to the fan inlet. This damper is modulated along with the firing rate of the burner by the FGR controller. At start-up the FGR control curve is characterized to provide the proper FGR rate across the burner operating range to achieve the desired NOx emission levels.

OPERATING SEQUENCE

The blower motor starts on a call for heat by the operating control and the pre-purge cycle begins. *At the end of pre-purge, the air louver must be in the closed (low fire) position for the low fire guarantee switch to close and allow ignition.

Also, at the end of pre-purge, the ignition transformer is energized and the pilot valves open, igniting the gas pilot.

The flame detector proves the flame and the main safety shutoff gas valves open, supplying gas to the orifices at the low fire setting of the butterfly metering valve and the burner ignites at the low fire rate.

The ignition transformer and pilot valve are de-energized.

After a short delay, the burner is released to modulate and the controller drives the fuel and air from the low fire position toward the high fire position to match the boiler load. At the same time the controller positions the FGR valve in parallel to control the NOx emissions.

As the boiler load is overcome, the controller drives the fuel, air and FGR back toward their low fire positions and the burner modulates over the range between low fire and high fire in response to the boiler load.

When the operating control is satisfied, the gas valves close and the blower motor is switched off, causing the burner to shut down and await the next call for heat.

The gas control equipment furnished and the minimum gas pressure required at the inlet to the controls are shown in the Burner Material List contained in the manual shipped with the burner.

Gas piping should be sized to provide the required minimum gas pressure at the main manual shutoff when operating at maximum input. Consult your local utility on any questions regarding gas pressure, piping pressure drops allowable and local piping requirements.

Gas piping should be installed in accordance with the American National Standard, ANSI Z223.1 and any other local codes which may apply. All gas piping should be tested after installation with air pressure or inert gas for at least three times the gas pressure that will be used.

The RMB burner uses very small gas orifices, which can be plugged by excessive dirt or debris in the gas system. To guard against this the piping ahead of the main manual shutoff shall include a 200 mesh strainer.

One of the most common oversights by an installer is failure to purge air, water, rust or other foreign matter from the fuel systems. DAMAGE TO BURNER, VALVES, PUMPS AND

OTHER COMPONENTS CAUSED BY RUST, WATER OR

FOREIGN PARTICLES IS NOT COVERED BY

WARRANTY.

* FGR valve should remain closed during purge cycle.

OIL SYSTEM PURGING

A standard method for purging oil systems is to remove the system pressure gauge (or plug where gauge would normally be installed) and temporarily install a piece of copper tubing long enough to drain into a bucket or other container.

The pump motor starter contacts are then manually depressed with a piece of wood or other non-conductor device and the pump allowed to run until purging is complete. There must be no sign of air, water, rust or other foreign matter in the flow.

If flow is not established within 2 minutes, the pump should be primed through the suction line. Reinstall gauge or plug after purging is complete.

Back off the back pressure regulating valve and oil pump relief valve to allow circulation at a few pounds pressure with all oil being returned to the tank. Run this way until entrained air is expelled then slowly build up the oil pressure in the circulating loop to 100 PSIG by tightening up the springs in these same valves.

The oil pump relief valve should be set to start opening at 5 to 10# above the setting of the back pressure regulating valve.

OIL PIPING INFORMATION - The F8 and F9 Oil Systems are used for modulating control in firing No. 2 fuel oil on gas-oil fired RMB and FRMB burners. Refer to Oil System Sheet included in the burner manual for application, description, and operating sequence of the applicable oil system.

FACTORY ADJUSTMENTS - The burner is adjusted at the factory to meet “dry run” conditions. Adjustments and initial settings must be checked prior to initial light-off and settings must be verified by combustion tests.

Depending on the model and capacity of the burner, various adjustment mechanisms control the air, fuel and FGR available for combustion, while others control the safe and reliable function of the gas-electric ignitor.

ADJUSTMENT MECHANISMS – Illustrations which follow show the items which are subject to adjustment.

Determine the applicability of each illustration to your burner, then proceed to familiarize yourself with the function of the item. Where a setting is indicated, verify the setting or make preliminary adjustments as necessary to facilitate initial start-up.

Adjustable air and fuel control mechanisms which modulate with the burner firing rate must be adjusted with the 0 to 90° actuator in the 0° position.

BURNER AIR AND FUEL

ADJUSTMENTS

Items 1 through 11

ITEM 1

ADJUSTMENT OF AIR INLET

LOUVER BOX

DESCRIPTION - The amount of air available for combustion is controlled by adjustable louvers located in the air box. The louvers are interconnected through a series of small linkage arms secured to a common drive rod.

HOW IT WORKS - See Figure 5-1. Louver opening and travel is controlled by adjusting the linkage mechanism from the actuator to obtain the desired opening and stroke. The actuator drives the louvers open or closed as the combustion control programs the burner firing rate to meet the boiler load.

ITEM 2

ADJUSTMENT OF GAS PILOT

IGNITOR ASSEMBLY

DESCRIPTION - The gas pilot ignitor is basically composed of:

1. An ignition electrode with insulator which generates an arc between it and the adjacent ground.

2. A fuel tube through which the gas is directed to the point of the electrical arc.

HOW IT WORKS - See Figures 5-2A and 5-2B.

A charge from a high voltage transformer is routed to the ignition electrode causing an intense arc to ground. The electrode is then immersed in a concentration of gas as the pilot solenoid valve opens allowing flow to the pilot. The arc ignites the gas, the electrical discharge from the transformer terminates and the pilot stands ready to ignite the main burner flame. On initial startup, pilot flame should be established with raw gas manual valve closed. After main pilot flame is set, raw gas manual valve must be opened enough to provide adequately sized and stable pilot.

PART V

COMBUSTION SYSTEM ADJUSTMENTS

Figure 5-1

PART V: COMBUSTIONS SYSTEM ADJUSTMENTS CONTINUED

Adjustment Procedure

Method I (High Turndown)

1. Use box end or socket wrench to loosen ball-joint connector.

2. To adjust low fire (minimum) air setting, loosen ball-joint connector holding drive rod and manually close all louvers.

3. Re-tighten ball-joint connector.

4. With a 3/32" Allen wrench loosen the set screws on the second from the top louver. Set the louver 3/8" open and tighten set screws.

Method II (Medium Turndown)

1. Use box end or socket wrench to loosen ball-joint connector.

2. To adjust low fire (minimum) air setting, loosen ball-joint connector holding drive rod and manually position louvers to obtain the desired opening, then re-tighten connector.

3. For initial start-up; position air inlet louvers so they are approximately 1/4" open.

To adjust amount of travel (stroke), loosen base of ball-joint connector located in slotted (louver) actuator arm and reposition to desired setting, then re-tighten connector.

A= Increases louver opening B= Reduces louver opening C= Slows opening of louver first 1" of travel D= Quickens opening of louver first 1" of travel E= Reduces louver opening F= Increases louver opening

NOTE

Air Inlet Louver Box

PART V: COMBUSTION SYSTEM ADJUSTMENTS CONTINUED

Figure 5-2A

Figure 5-2B

ITEM 3

ADJUSTMENT OF BUTTERFLY

GAS VALVE

DESCRIPTION - The butterfly gas valve is a fuel throttling device which proportions the gas in proper ratio to the combustion air. The valve is opened or closed by an actuator as the combustion control adjusts the burner firing rate to meet the boiler load.

HOW IT WORKS - See Figure 5-3. A centrally located disc turns within a cylindrical body which regulates the gas flow to the main burner flame. The butterfly valves used are the non-tight shutoff type.

Through a linkage system, or using a linkageless servo motor and air-fuel ratio controller, an actuator drives the valve open or closed in response to electrical signals from the combustion control. Since the amount of air available for combustion is controlled by the same actuator, or air-fuel ratio controller, a proper fuel-air ratio is maintained at all times.

ITEM 4

ADJUSTMENT OF GAS PRESSURE

REGULATORS

DESCRIPTION - Gas burners have two gas pressure regulators, one to regulate the pressure to the main flame and the other to regulate the gas pilot ignitor.

HOW IT WORKS - See Figure 5-4. Simply stated, gas flow is controlled by a spring of known load range which works against the supply (from the meter) gas pressure.

Accordingly, each regulator must be fitted with the right spring for it to function properly. Additionally, the tension on the regulator spring must be adjusted to obtain the exact gas pressure required at the inlet to the controls.

ITEM 5

ADJUSTMENT OF GAS PRESSURE

SWITCHES

DESCRIPTION - Gas pressure switches are pressure-actuated electrical switching devices designed for safety shutoff when gas pressures are either too low or too high.

HOW IT WORKS - See Figure 5-5. The pressure switch senses any change in gas pressure and, if properly adjusted, will transmit an electrical signal to the automatic shutoff valve and/or other interlocking devices when an unsafe condition exists. The burner will then re-cycle or completely shut down depending upon the flame safeguard used. Gas pressure switches are designed to operate over a specified pressure range; therefore, each switch must be selected to be compatible with the burner operating gas pressure and also to obtain the desired electrical features.

PART V: COMBUSTION SYSTEM ADJUSTMENTS CONTINUED

Figure 5-3

Figure 5-4

Figure 5-5

ITEM 6

ADJUSTMENT

OF OIL DRAWER

ASSEMBLY

DESCRIPTION - Oil burners have an assembly made up of vital oil and air handling components known as the “Oil Drawer Assembly”. Basically, this assembly contains the oil tubes, the atomizing nozzle(s), and backplate which secures the unit to the burner housing.

HOW IT WORKS - See Figure 5-6. The oil and air are delivered to the nozzle through a tube-within-a-tube arrangement.

The outer tube carries the air while the inner tube carries the oil.

Oil and air pressures are indicated by gauges located in the air/oil distributor block.

The air and oil enter the mixing chamber of the nozzle, then the atomized oil is forced out the nozzle into the stream of combustion air.

The burner distributes the combustion air through the atomized oil which is then ignited by the gas pilot ignitor.

ADJUSTMENT PROCEDURE

REMOVAL:

1. Tighten set screws to hold guide tube and oil gun securely in position.

2. Disengage fittings on oil supply and air lines.

3. Loosen set screws and remove oil gun through burner back plate.

4. Install cover plate provided onto guidetube end.

To re-install the oil gun, reverse the order of the steps outlined above.

In the following step, do not permit front end of drawer assembly to fall as the oil gun slides out of the guide tube. Nozzle may be damaged requiring repair or possible replacement.

CAUTION

PART V: COMBUSTION SYSTEM ADJUSTMENTS CONTINUED

Figure 5-6

Oil gun must be removed from the burner before firing gas and cover plate installed. If the oil gun is left installed durning gas firing, damage to the oil nozzle will occur.

ITEM 7

ADJUSTMENT OF

OIL METERING VALVE

DESCRIPTION - See Figure 5-7. Oil burner fuel control systems must deliver oil to the nozzle at reduced pressure for low fire. This is normally accomplished by diverting a portion of the oil pump delivery thru a bypass return line to the tank.

The amount of oil delivered to the nozzle versus that returned to the tank is controlled by a device which limits or meters flow, thus an oil metering valve is commonly used for this purpose.

HOW IT WORKS - Most oil metering devices work on the principle of limiting flow by constricting the area thru which the oil must pass. In order to vary the orifice area, mechanical movement must take place, thus the oil metering valve requires an actuator to do its job. By interconnecting a common actuator to the combustion air control and the oil metering valve, or using a linkageless parallel positioning controller, this allows the fuel (oil) to be proportioned in precise ratio to the amount of air available for combustion, This feature is essential on modulating type fuel control systems.

ITEM 8

ADJUSTMENT OF OIL SUPPLY

PRESSURE REGULATOR VALVE

DESCRIPTION - See Figure 5-8. Oil burners require a close regulation of the pressure at which oil is delivered to the nozzle. RMB/FRMB burners normally use an oil pump which has a separate pressure regulating valve.

HOW IT WORKS - Burner oil pumps are generally identified by the rate at which they can deliver (GPH), the pressure of the delivery (PSI) and the speed of rotation (RPM). The pump is usually capable of delivering more fuel than is required to meet firing requirements; therefore, the amount of oil delivered to the nozzle must be controlled. This control is accomplished through use of an adjustable pressure regulating valve which reduces flow to the nozzle by causing more oil to be returned to the tank. Like most regulators, flow is controlled by an adjustable spring and each regulator has a pressure range over which it will reliably operate.

PART V: COMBUSTION SYSTEM ADJUSTMENTS CONTINUED

Figure 5-7

Figure 5-8

See item 1 for adjustment notes.

ITEM 9

ADJUSTMENT OF LOW OIL

PRESSURE SWITCH

DESCRIPTION - See Figure 5-9. Low oil pressure switches are often times used to insure the oil pressure at the nozzle is adequate for proper atomization of the oil.

HOW IT WORKS - A pressure sensing device within the switch controls an electrical circuit normally interlocked with the flame safeguard causing the burner to recycle or shut down when the pressure sensed falls below the setting.

ITEM 10

ADJUSTMENT OF CHARACTERIZED

LINKAGE

DESCRIPTION - See Figure 5-10. Characterized linkage provides the mechanical means to fine tune the fuel input (flow) to the burner in order to achieve maximum fuel efficiency and reduce harmful stack emissions.

HOW IT WORKS - There are nine (9) adjustment screws which control the contour of a flexible metal track upon which a roller and plunger mechanism travel. This mechanism in turn controls the linkage to the fuel valve, providing the precise amount of travel to dispense the right amount of fuel to the burner as it modulates to meet load demand. The objective is to shape the flexible metal track into what amounts to a “combustion efficiency profile.”

ITEM 11

ADJUSTMENT OF AIR FLOW SWITCH

[DIAPHRAGM]

DESCRIPTION - See Figure 5-11. The air flow switch is used to prove the flow of combustion air from the blower assembly. It causes the fuel valve to close or fail to open upon loss of or inadequate combustion air.

HOW IT WORKS - The air flow switch is wired in series with the flame safeguard. When the blower starts, creating an air flow through the burner housing, the switch closes delivering electricity to the flame safeguard.

Figure 5-9

Figure 5-10

Figure 5-11

PART V: COMBUSTION SYSTEM ADJUSTMENTS CONTINUED

Table 6-1

RECOMMENDED PRE-FIRING CHECKLIST

RMB ULTRA FRMB

Correct Ignitor Location

Adequate Ignitor Air Supply

Purge Air to Scanner

Fan Outlet Damper Present N/A

Oil Gun Removed

Refractory Correctly Installed

Gas Line Cleaned

Gas Strainer Present

Min. and Max. RDL Properly Set

FGR Line and Valve Correctly Installed

Due to wide variations in engineering specifications, state and local codes, utility and insurance underwriters requirements, etc., the contents herein are of a general nature.

If additional information is required or if questions arise concerning specific requirements, please contact your local representative or the factory.

FLAME SAFEGUARD INSTALLATION - Assure flame safeguard is properly installed in its sub-base.

IDENTIFICATION OF CONTROLS - Review the burner operating sequence and wiring diagram in the instructions manual. Study these items and identify the various controls.

PART VI

BURNER START-UP

This bulletin has been prepared as a guide in burner start-up operations. It is written for the start-up specialist who is thoroughly qualified both by training and experience.

CAUTION NOTE

The burner flame safeguard is often times packaged and shipped in a separate carton; however, the control cabinet will contain the mounting sub-base which is installed and pre-wired at the factory. See separate instructions on flame safeguard for mounting the unit in the sub-base.

Start-up and initial tuning of an RMB should only be performed by a trained John Zink service person and/or factory approved personnel.

IGNITOR

Before firing the boiler, several installation details of the ignitor must be checked. These features include:

1. The ignitor should be recessed about 2 inches back inside the refractory quarl. If any portion of the ignitor sticks out into the furnace, it will be destroyed.

2. Because the ignitor is positioned inside the burner, air must be piped to the ignitor from a clean, external source.

FLAME SCANNER

It is recommended that the flame scanner be equipped with purge air (2 to 3 SCFM).

AIR POSITIONERS, DAMPERS AND

LINKAGE

Depending on the turndown required, the stroke on the positioners and dampers should be set prior to starting the burner. Table 6-2 lists good starting estimates for the minimum and maximum register draft losses (RDL) (windbox to furnace pressure drops) for various applications.

The information in Table 6-2 also shows maximum turndown allowable for ranges of operating conditions. The table should be viewed as a guide only, and if the guaranteed turndown is less than the maximum turndown listed, then the minimum RDL value should be adjusted accordingly.

The maximum turndowns listed here are determined on the basis of a minimum air flow to prevent burner overheating.

In no cases should the burner be fired with a lower RDL than listed in Table 6-2, unless it is carefully confirmed that no overheating is occurring. FGR should be set to provide windbox O2 levels per Figure 6-3.

There is no major problem in setting the maximum RDL higher than listed in Table 6-2. If the maximum RDL is set significantly higher than shown in the table, less than full stroke of the positioner will be used. Effectively, this would result in a minor loss of accuracy in setting the air flow.

DUAL FUEL BURNERS

If the burner is a dual fuel burner, the oil gun must be removed before firing gas. Additionally, the core air supply (the air pipe which comes out of the windbox and into the annulus surrounding the oil gun) should be fully closed. If the core air annulus appears to be overheating when the burner is in operation on gas, a small amount of core air can be used for cooling.

If the burner is a combination gas-oil unit, it is recommended that the burner be fired on gas first so the correct input rate in BTU’s per hour may be determined by reading the gas meter.

PART VI: BURNER START-UP CONTINUED

NOTE

Do not proceed with start-up unless all applicable checklist items in Table 6-1 and preliminary adjustment requirements in Part V have been satisfied.

Table 6-2

REQUIRED NOx REQUIRED CO MAXIMUM MINIMUM MAXIMUM TURNDOWN RDL in WC RDL in WC

<9ppm <50ppm 3:1 1.0 9.0

<9ppm <100ppm 4:1 0.5 9.0

<12ppm <50ppm 4:1 0.5 9.0

<12ppm <100ppm 5:1 0.35 9.0

START-UP SETTINGS OF BURNER

CONTROLS

During initial start-up, the operator must be on constant alert for emergency conditions such as fuel leaks, electrical malfunctions, etc. The location of all manual shutoff valves and disconnect switches should be clearly in mind so the burner can be quickly shut down if necessary.

Using the Manufacturer’s Instructions Bulletin on the flame safeguard, proceed with checkout to insure proper function of the safeguard under burner operational conditions.

GAS FIRING

REVIEW BURNER MATERIAL LIST IN THE

INSTRUCTIONS MANUAL AND ANNOTATE THE

FOLLOWING INFORMATION:

(1) Firing Rate (MBH)

(2) Cubic Feet of Gas per Hour (CFH)

(3) BTU per Cubic Foot (BTU/CF)

(4) Required Gas Pressure at Control Inlet (inches w.c.)

(5) Required Gas Pressure at Orifices taken at burner manifold (inches w.c.)

The above information is pertinent to starting up the burner.

The Rapid Mix Burner system you have purchased is a highly engineered, state of the art, combustion device. The RMB system is highly automated, and typically will require only routine maintenance. This section describes the operation of a typical boiler system after it is set up by John Zink service engineers. If the operation of the RMB system installed at your plant differs from the automatic operation described in this section, John Zink should be immediately contacted to ensure that your system is properly set-up. Adjustment of the burner or controls should only be performed by John Zink trained personnel. Adjustment by non-qualified personnel can result in unsafe operating conditions, damage to equipment and/or injury to personnel.

Additional maintenance items, other than those listed here, may be required by equipment vendors, company policy or insurance requirements.

Operation of this equipment should always be performed in a manner consistent with plant and operating rules and the requirements of other system components (furnace, boiler, etc.).

PART VI: BURNER START-UP CONTINUED

NOTE

While performing these checks, certain adjustments and readings must be made at the appropriate time.

These include, but are not limited to:

(1) Burner Combustion Air

(2) Gas Pressure (at control inlet and orifice)

(3) Boiler Limit Controls

(4) Draft Controls

(5) Other Controls Electrically Interlocked with the Burner Control System.

(6) Gas Flow through Utility Meter (CFH)

(7) O2, NOx and CO in stack

(8) Stack Temperature

(9) O2 in Windbox

(10) FGR

(11) Furnace Pressure

Be certain combustion chamber, flues and surrounding areas are free of gas accumulations, oil or oil vapor and other combustibles such as paint thinners, cleaning solutions, etc. An explosimeter (Mine Safety Appliances Co., Model No. 2A, or equivalent) should be used to make this determination.

WARNING!

Should the burner fail to ignite, never manually manipulate the flame safeguard sequence which provides for purging of the combustion chamber.

Note that before starting the burner on gas, the oil gun must be removed or withdrawn inside the guide tube. If a gaseous flame is started with the oil gun inserted, the oil gun will be damaged.

Operation on gas firing is completely automatic. To start the burner, the appropriate switches on the burner management panel should be placed in the “on” position. Typically this entails ensuing the fan is running (either in the automatic or manual position) and the burner switch is turned on or the burner start push button is depressed. If the burner is a dual fuel burner, set the fuel switch to the gas position. Depending on how the burner was shut down previously, the reset button may have to be pushed. If all start interlocks are satisfied, the burner purge will begin automatically. Following the burner purge, the combustion controls will go to the light-off position and if the correct low fire interlocks are made, the pilot ignition trial will begin. If a pilot flame is detected, the main flame ignition trial will begin and upon successful ignition of the main flame the pilot is turned off and the combustion controls will be released to modulate.

Once the main flame has been started, the control loops should transition to automatic with the only loop remaining in manual being the burner firing rate demand controller. The air, fuel, and FGR loops should go into full automatic without any operator intervention required.

The burner should remain at low fire until the boiler reaches operating pressure and/or temperature. The boiler operating instructions should be consulted to determine the maximum heat up rate for the equipment. If a slower rate is desired than obtained with the burner at low fire, the burner can be cycled on and off to yield a reduced rate. When the furnace reaches the operating temperature or pressure the firing rate demand can then be placed in automatic. The control system will then maintain the proper process set point.

TUNING ON GAS

Once the refractory has been properly cured, the fuel, air and FGR inputs can be set up over the load range. Initially, it is desirable to start the burner at minimum load to ensure proper operation. Do not operate the RMB with less than the RDL shown in Table 6-2, unless you are sure that the flame is maintained in the refractory portion of the burner. Normally, the RMB would be started with the FGR on and then set approximately to the desired rate for NOx control. At minimum load, tune the boiler to the desired excess air rate, FGR, and NOx level.

Slowly increase the load, and again set the excess air and FGR rate to the desired levels. The FGR rate can be calculated by measuring the windbox O2 and using Figure 6-3. Repeat this procedure until the correct settings are obtained over the load range. Decrease the load in steps to minimum and readjust the excess air and FGR at any points in the load curve where required.

PART VI: BURNER START-UP CONTINUED

Figure 6-3

AUTOMATIC OPERATION ON GAS

When the controls are put into automatic, ensure that the control system is maintaining the proper stoichiometry over the load range, especially when operating at the maximum rate of load changes. Typically, the excess air should be maintained within +/- 5% of the setpoint (+/- 1% O2) and the FGR rate should also be maintained within 5 percent. If the excess air or FGR is allowed to exceed this range, flame stability may be lost, while if the O2 is too low, vibration problems may result.

FLAME CONSIDERATIONS FOR GAS

FIRING

The flames of a burner allow the operator a method of judging the efficiency and proper operation of the burner.

They can be used to judge operation of the burner but cannot be used to tune the burner.

A principle feature of the burners is that an extremely stable primary flame is formed, and it is difficult to extinguish the flame with high combustion airflow. However, the fact the flame does not blow out does not mean that optimum air volumes are being used. High excess air levels may result in a proper flame appearance even though excessive amounts of CO are been produced.