Maxon Tube-O-Therm Low Temperature Direct Firing Burner
Contents
1. M A O Ri Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice CORPORATION MUNCIE INDIANA USA INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES TUBE O THERM Gas Burners Page 2750 S 7 Service Tips continued NOTE The chart below shows normal differential combustion air pressure readings in a no fire condition These readings will increase when burner is firing The fuel gas pressures shown are at high fire condition Natural Gas 32 1 59 25 8 56 9 29 2 62 1 33 0 72 0 Pressure wc 1 Propane Gas 13 6 29 12 9 28 4 15 4 33 7 16 5 37 0 Pressure wc 1 1 at burner gas test port If your reading is higher than these cold air pressure readings you have a suction in your tube This condition should not be a problem If your reading is lower than the cold air differential pressure reading you have a back pressure in your tube If an exhaust stack damper is used check that it is fully open and locked in place Excessive back pressure can cause high CO emissions smoke and carbon in firing tube and will restrict firing capacity of burner Additional Service Tips NOTE The differential air pressure setting determines the burner s capacity and perfor mance capabilities NOTICE Burner performance can be drastically affected by tube configuration and static conditions within tube created by da2. a few hours The fuel throttling valve contained within a Maxon burner is not intended for tight shut off Main gas regulator is essential to maintain a uniform system supply volume and pressure If one pipe train supplies multiple burners provide a sepa rate regulator in the branch leading to each burner system It is recommended that the regulator be sized for at least 120 of full system capacity at the required pressure carefully considering pipe train losses Follow the instructions attached to the regulator during installation Refer to page 2758 for burner inlet pressure requirements Pilot take off should be upstream of the main gas regulator but downstream of the main gas cock It should normally include its own pilot gas regulator a solenoid valve and shut off cock The pilot adjustable orifice at the pilot inlet simplifies adjustment NOTE Most regulator manufacturers include an internal relief valve in their standard regulators These relief valves will begin to vent when the downstream pressure is somewhere around 7 inches w c greater than the regulator set pressure Regulators can be ordered without an internal vent The best option is to run the pilot interrupted If the pilot is not interrupted catalog minimums cannot be obtained Pilot piping must be large enough to provide for the full flow and pressures shown in the catalog for your particular burner size Pilot solenoid should be located within 5 f
3. block if used may affect signal strength with some brands of scanners Alternate fuels may require correction of supply pressures Multi burner installations require special consid erations if supplied by a common pipe train and or air supply Air and Gas Balancing Valves should be used for improved heating uniformity Gas Swing Check Valves should be installed as close as possible to each burner inlet for dependable light off gas mani fold may otherwise act as a reservoir preventing light off during trial for ignition period Control system s circuitry must not allow main Fuel Shut Off Valve to be opened unless combustion air is on and must de energize valve upon loss of combustion air pressure along with the other usual system interlocks Motor starter is to be interlocked with valve whether or not a combustion air pressure switch is used Because of the high firing rates possible with this burner and the low cross sectional area of the tubes no draft or chimney effect should be de signed for or expected if the exhaust stack diameter is equal to the fired tube diameter Immersion tubes are usually vented to the outdoors except for those in highly ventilated areas such as a plating room with continuous high volume exhaust An exhaust fan may be required if the building is under negative pressure Exhaust is normally diluted to avoid the need for high temperature fans but adequate make up air must be
4. internal gas valve is characterized to the air butterfly valve and is based on the specified inlet gas pressures Operation outside of these specifications will result in unsatisfactory burner performance 14 Establish high fire setting by slowly moving burner crank toward high fire position while observing gas pressure at burner gas test inlet Refine main gas regulator adjustment as neces sary to provide correct differential gas pressure at high fire If pressure cannot be adjusted high enough a different regulator or regulator spring may be necessary Do not however exceed 6 wc pressure drop between regulator outlet and burner inlet With interrupted pilot it may be necessary to set control for somewhat higher than minimum burner setting to permit hold in of flame detection system without pilot CAUTION Internal drive mechanism within the control motor may be damaged if linkage is adjusted so as to cause binding with burner in high or low fire position CAUTION If burner s go out close shut off valve or shut main gas cock at once Return to minimum setting re light pilots if necessary then turn main gas on again Check carefully that every burner is lit before proceeding 2 98 Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES 17 Re check differential gas p
5. off valves automatic fuel shut off valve should already be open so gas flows to burner inlet There should be little if any change in flame appearance Turn main regulator adjust ing screw in clockwise until gas pressure at the burner inlet upstream of the burner is as speci fied on page 2758 Main flame should now appear larger than pilot only flame Cycle burner from minimum to maximum and refine adjustment if necessary For operation with interrupted pilot shut off pilots and cycle burner from minimum to maxi mum and back several times to verify the flame is maintained 15 When burner performance is satisfactory and stable throughout the firing range reconnect linkage to control motor Control linkage travel must be such that burner crank is moved throughout its complete travel or cataloged capacities and turndowns will not be achieved 16 If attempts to start up burner have been unsuccessful to this point refer to Service Tips on pages 2750 S 6 and 7 NOTICE If less than full rated burner capacity is required adjust control motor and or motor gas shaft linkage to limit maximum output Do not adjust gas air linkage At cold start up some rumbling will occur as the tube warms up To reduce or prevent this rumbling a low fire time period of approximately 2 minutes before continuing on to high fire is recommended CAUTION Do not limit capacity by adjusting gas pressure to the burner inlet The
6. TUBE O THERM Gas Burners Page 2750 S 1 Installation Instructions General Instructions Important Do not discard packing material until all loose items are accounted for To prevent damage in transit the spark ignitor mounting gaskets and connecting linkage compo nents may be packed separately and shipped loose with your new Maxon TUBE O THERM Burner The burner itself is normally only a part of your complete combustion system Additional pipe train accessories and control components will be required for a complete system installation TUBE O THERM Burner provides the air supply unless it is EB version which requires a separate combustion air blower It also serves as a fuel flow control and fuel air mixing device Burner should not be exposed to direct radiant heat or positioned where it might draw in inert gases If such conditions exist consider filters relocation and or use of the EB version and external air supply Electrical service must match the voltage phase and cycle of all electrical system components and be compatible with burner nameplate ratings Insure that all normal control safeguards are satisfied Combus tion air blower should continue to run after shutdown to allow burner to cool NOTE Burners supplied with standard blower motors have dual voltage capability 230 460v 3 Ph 60 Hz 115 230v 3 Ph 60 Hz 190 380v 3 Ph 50 Hz Failure to connect plant voltage to proper fan wir
7. Use only gas tight scanner connections 20 Before system is placed into full service instruct operator personnel on proper start up operation with shut down of system establishing written instructions for their future reference Service Tips On occasions during cold start up a rumbling will occur in the tube until thermal equilibrium is estab lished This is normal and should disappear within a few minutes A low fire time period of approximately 2 minutes is recommended prior to high fire operation If after several minutes of high fire operation the rumbling has not decreased or the burner exhibits flame instability shut off the burner and perform the following checks 1 Start all system related fans and blowers to duplicate conditions from step 6 of start up instructions on page 2750 S 4 Advance burner operating crank to high fire position 2 Determine and verify differential air pressure at burner backplate test ports Connect a manometer between the gas test port and the air test port With the burner operating crank at high fire position fuel valve s closed air handling systems and combustion air blower on the manometer will read the differen tial combustion air pressure Air test port should be connected to the end of the manometer as it will have the higher pressure over the gas test port TUBE O THERM Burners 1 8 Gas Test Port 1 8 Air Test Port
8. available This diluting can be done with an open tee installed in a vertical run or in a horizontal run with the open end down but such a system mixes slowly An adjustable hood shown in sketch below offers much better performance In all cases care must be taken that all products of combustion are exhausted from the building To Fan To Fan a Diluting Xe Air Tee All Adjustments to be Locked in Position yH K Diluting Air Ba Adjustable Hood Immersion Immersion Tube Tube Open Tee Adjustable Hood supplied by others Cross sectional area of the exhaust hood should be a minimum of 1 5 times the fired tube cross sectional area M A O Ri Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice CORPORATION MUNCIE INDIANA USA INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES TUBE O THERM Gas Burners Page 2750 S 3 Installation Instructions Wall mounting installation recommended and stub mounting The TUBE O THERM Burner was designed to For most applications the wall mounting option transfer heat to your process as efficiently as pos is recommended Use of the wall mounting option sible As a result your process tube which bolts to will support the burner off of the tank instead of the outlet of the TUBE O THERM Burner can supporting the burner with the tube Maxon also become hot during the burner
9. ed for the burner mounting Therefore Maxon will supply metric nuts with the burner Customer should apply an anti seize thread lubricant to mounting bolts before installing burner onto flange connection After placing burner in position add lock washers and nuts then draw up hand tight only Check that burner is centered then tighten all nuts firmly For proper performance of any burner air inlet and motor should be surrounded by clean fresh cool air Burner and pipe manifold support will be re quired to support weight of the burner and connected pipe train components Air control motors in particu lar require additional support Maxon connecting base and linkage assemblies are designed to position the control motors to work with the burner not to support their weight The TUBE O THERM Burner may require external auxiliary support provided by the user Additional burner support may be required in conjunction with a stiffener plate when mounting TUBE O THERM Burner onto tube or thin tank walls Protective covers for burner should be added in the field if exposure to dripping condensate splashing flux exhaust steam etc is unavoidable Any such cover should be removable to provide access to burner and should not interfere with control linkage motion observation port viewing or air inlet Flame sensing is accomplished by a UV scanner Keep scanner as close to burner as feasible Do not use cooling air to scanner port Heat
10. eet of burner to allow gas to reach burner before flame safeguard times out The 3 8 pilot connection of the TUBE O THERM Burner is adequate for the pilot gas flows shown but care must be taken to assure that the required gas pressure 8 12 wc and flow are available at pilot inlet Fuel Shut Off Valves when properly connected to a control system shut the fuel supply off when a hazardous operating condition is sensed Manual reset valves require operator attendance each time the system is started up or restarted after a shut down Motorized shut off valves permit automatic start restart when used with an appropriate control system MAXON CORPORATION MUNCIE INDIANA USA Page 2750 S 2 TUBE O THERM Gas Burners Installation Instructions Test connections are essential for burner adjust ment They should be provided immediately down stream of the regulator and are included in the burner itself Test connections must be plugged except when readings are being taken Horizontal mounting of the burner is preferred but burner may be mounted in any position suitable for automatic control motor and UV scanner Burner mounting requires a standard 150 flange to fit the burner s studs four studs for 3 burner eight studs for 4 6 and 8 burners Burner mounting gasket is a standard 150 flange gasket supplied by Maxon Although the mounting uses standard ANSI dimensions metric bolts are us
11. ertaken only by trained and adequate purge of your manifolds and immersion experienced personnel familiar with combus tubes With main gas shut off manually advance tion systems with control safety circuitry and TUBE O THERM Burner s operating crank to with knowledge of the overall installation high fire position 90 so that air only flows Instructions provided by the company and or through burner and immersion tube individuals responsible for the manufacture and or overall installation of complete system CAUTION Do not bypass control panel timers incorporating Maxon burners take precedence typically controlling sequential operations OVS ihese provided By Maxon If Maxon 7 Determine the required gas pressure from instructions conflict with any codes or regula 3 chart on page 2758 tions contact Maxon Corporation before attempting start up NOTE Gas pressures shown on page 2758 are under actual high fire conditions once proper differential air pressure has been established Yes oe o eee For initial TOBE O THERM Burner staitup 8 Verify that spark ignitor is properly positioned 1 Close all burner fuel valves and cocks Make and bottoms out inside the burner air plate preliminary adjustments to fuel gas regulators Remove pilot and main gas regulators adjusting screw covers Turn adjusting screw down clock wise to approximately mid position Close pilot NOTE Field experience shows that a fu
12. ing will result in poor burner performance Refer to wiring diagram on fan motor Gas supply piping must be large enough to maintain the required fuel pressures cataloged for the particular burner size used with burner operating at full rated capacity Anything more than minimum distance or piping turns may necessitate oversizing piping runs to keep pressure drops within acceptable ranges Inlet pipe leading to any burner should be at least four pipe diameters in length If multiple burners are fed from a single gas train care should be taken to minimize pressure drop and give maximum uniformity NOTE Multiple burner installations fed by a single pipe train should incorporate a balancing valve and a swing check valve installed as close as possible to each burner gas inlet for improved heating uniformity and more dependable light off Otherwise gas manifold may act as a reservoir preventing reliable light off during trial for ignition period of your control panel sequence 10 99 Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES Clean fuel lines are essential to prevent blockage of pipe train components or burner gas ports Main shut off cock should be upstream of both the main gas regulator and pilot line take off Use it to shut off fuel to both pilot and main burner during shut down periods of more than
13. ll wave spark ignition transformer provides a reliable ignition source gas adjustable orifice screw by turning in clock 9 Return burner control valve crank to low fire wise until it stops Do not over tighten Then position when purge of system is complete back out the adjustable orifice counter clockwise 10 Open main and pilot gas cocks activate spark approximately 2 3 turns ignition transformer and pilot gas solenoid valve 2 Check all electric circuitry Verify that all control then attempt pilot ignition to light pilot while slowly devices and interlocks are operable and function turning pilot gas regulator and or adjustable orifice ing within their respective settings ranges Be screw counter clockwise to increase fuel flow sure all air and gas manifolds are tight and that Repeat procedure as necessary until pilot ignites test ports are plugged if not being used as air might have to be bled out of fuel supply 3 Check that the immersion tube stack damper lines before reliable pilot flame is established is fully open and locked into position Stack Pilot gas regulator should normally be set for as dampers not required and can block exhaust even low a pressure as possible using fuller opening of if open pilot gas adjustable orifice 4 Check that air and gas pressure switches are 11 After ignition adjust pilot to provide pilot gas not marginally set to prevent troublesome system pressure as specified on page 2758 Use a
14. mpers in exhaust stack 3 All TUBE O THERM Burners are shipped with the air gas linkage factory set Check centerline to centerline dimensions on the air gas linkage to determine that it is the proper length per dimen sion B shown on pages 2759 2761 The linkage is fabricated as a turnbuckle style link To adjust simply loosen the locknut and twist the arm clockwise to shorten or counter clockwise to lengthen the linkage 4 If air gas linkage dimension is correct per dimen sions shown on pages 2759 2761 check wiring diagram to blower motor to determine that dual voltage motor has been wired properly Failure to do so will result in differential air pressure read ings that are out of specification Correct wiring errors as necessary 5 If stack damper is used in error make certain it is full open and locked may need to be removed Problem Cause s Pilot fails to light 1 On initial start up gas line may be filled with air Repeat ignition trial several times to purge 2 No power to ignition transformer or pilot solenoid 3 Open circuit between ignition transformer and ignitor plug 4 Pilot gas cock adjusting screw closed 5 Insufficient gas pressure into or out of pilot regulator Main flame fails to light or goes out 1 Insufficient pressure into or out of main gas regulator as burner cycles to high fire 2 Marginal air pressure switch setting 3 Marginal gas pressure switch setting 4 Incorrect combus
15. pilot shutdown during start up Set pressure switches gas pressure regulator that provides 8 12 wc gas with some cushion for start up and re adjust pressure to the pilot gas inlet during final system tuning 5 Disconnect the automatic control motor s linkage from your TUBE O THERM Burner s operating crank arm by loosening the control motor s connecting rod from the burner s linkage mM A O Ri Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice CORPORATION MUNCIE INDIANA USA INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES TUBE O THERM Gas Burners Page 2750 S 5 Start Up Instructions 12 Re check pilot ignition by closing pilot gas cock or otherwise causing pilot outage Re light and refine pilot gas adjustment as necessary to get ignition within a second or two The flame safe guard relays should now power your main fuel Shut Off Valve s CAUTION After completing previous steps re check all interlocking safety components and circuitry to prove that they are properly in stalled correctly set and fully operational If in doubt shut the system down close pilot cock and contact responsible individual before proceeding further 13 Establish main flame With burner at low fire position back out main gas pressure regulator adjusting screw counter clockwise to get lowest outlet pressure possible Open all manual fuel shut
16. ressure with unit at operating temperature Refine high fire setting if necessary considering differential pressure flame stability and appearance Dust or contami nants in the air stream may affect flame appear ance 18 Plug all test connections not in use to avoid dangerous fuel leakage Replace equipment cover caps and tighten linkage screws MAXON CORPORATION MUNCIE INDIANA USA Page 2750 S 6 TUBE O THERM Gas Burners Start Up Instructions 19 Check out overall system operation by cycling through light off at minimum interrupting pilot and allowing temperature control system to cycle burner from minimum to maximum and return NOTE Typical gas firing control sequence for Maxon burner is provided only as a guide Instruc tions provided by complete system manufacturer incorporating Maxon burners take precedence For gas firing TUBE O THERM Burner Light off Shut down 1 Close cocks shut off valve s 1 Close main amp 2 Verify burner at low fire pilot gas cocks 3 Start recirculating exhaust fans 2 Keep combustion 4 Start burner blower air blower running 5 Purge at least 4 air changes after shut down long 6 Open pilot amp main gas cocks enough to allow burner to cool Recheck all safety system interlocks for proper setting and operation WARNING Test every UV installation for dangerous spark excitation from ignitors and other possible sources of direct or reflected UV radiation
17. rsion tube should extend no more than 1 2 past this outside wall Wall Mounting Plate Maxon to be welded to customer s tank l Gasket Maxon high temperature RTV applied between burner body and gasket only i Existing Weld tank wall tube Immersion Tube customer s I D of Maxon supplied mounting plate is 3 4 larger than O D of tube This is to allow a gap for weld As an option to seal welding the O D of the mounting clearance where the tube welds to the tank wall plate customer can seal weld the I D to prevent leakage of hot products of combustion RA Ri 8 00 Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice y O CORPORATION INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES MUNCIE INDIANK USA Page 2750 S 4 TUBE O THERM Gas Burners Start Up Instructions Read complete instructions before proceeding Initial start up adjustment should only be and familiarize yourself with all the system s equip accomplished during a manual burner control ment components Verify that your equipment has mode been installed in accordance with the original manu 6 Start all system related fans and blowers facturer s current instructions Check for proper motor rotation and impeller direction Verify that all control interlocks are CAUTION Initial adjustment and light off working Allow air handling equipment to run for should be und
18. s operation suggests using a burner support independent of the flange which will allow for some expansion during firing Consult your Maxon representative for more information On optional stub mounted versions the inlet portion of this tube will overheat if it extends too far outside the tank The maximum recommended length for the initial To install the wall mounting portion of your process tube outside the tank is 1 Insert the immersion tube through the tank wall shown making sure that it extends no more than 1 2 past Burner flange to inside of tank wall maximum the outside of the wall the tube should be as flush Dimension C 3 burner 2 5 as possible with the Wall Mounting Plate once it is Dimension C 4 burner 2 5 installed Dimension C 6 burner 2 5 2 Weld the immersion tube to the tank wall Dimension Cr 8 burner 3 3 Slip the Wall Mounting Plate over the immersion tube with the screw heads facing the tank wall and seal weld the I D to the tank wall Optional Continuous weld the O D of the mount ing plate If I D is seal welded O D should be intermittant welded for rigidity and strength 4 Attach the burner to the mounting bolts Stub mounted installation Tank Wall inside 4 Tank Wall outside Hex Nut TUBE O THERM one Burner Immersion Tube Wall mounted installation Tank Wall customer s A TUBE O THERM Burner imme
19. tion air pressure Burner is unstable or produces 1 Gas air ratio out of adjustment Adjust fuel pressures and or air soot smoke or excessive carbon linkage as instructed under Service Tips monoxide 2 Air filter to combustion air fan is plugged or dirty Replace or clean 3 Exhaust stack damper is closed or partially closed or another restriction exists in the fired tube system 10 99 Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES M AXON CORPORATION MUNCIE INDIANA USA Page 2750 S 8 TUBE O THERM Gas Burners Notes M A O R Maxon practices a policy of continuous product improvement It reserves the right to alter specifications without prior notice CORPORATION MUNCIE INDIANA USA INDUSTRIAL COMBUSTION EQUIPMENT AND VALVES
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