Furnace Operating Procedure

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This procedure explains how to start up Pusher Furnaces 11, 12, or 13 after a Long Term / Maintenance shutdown. A Long Term / Maintenance shutdown is when the furnace has been shutdown and allowed to cool to room temperature.

Before starting up the Pusher Furnace, make sure the Furnace is clear of all tools, parts, and equipment.

The Hand Torch and Pilots can cause serious burns. Use caution when using the Hand Torch to light Pilots.

PROCEDURE:
  1. Move the main disconnect switches located on the Heating and Atmosphere Control Cabinet and the Operation Control Cabinet to the ON position

    If the disconnect switches are locked out, the lockouts must be removed according to local plant policies and procedures.
  2. Move the Endothermic Gas Lockout Blank from the closed position to the open position. The part of the Lockout Blank that is showing after you do this step must NOT have a hole in it.

    Steps 2-4 require a Pipefitter and must be performed according to local plant policies and procedures.
  3. Move the Natural Gas Lockout Blank from the closed position to the open position. The part of the Lockout Blank that is showing after you do this step must NOT have a hole in it.
  4. Remove all shutoff valve lockouts according to local plant policies and procedures.
  5. Open the Main Cooling Water Shutoff Valve (P11-V1). When open, the valve handle will be in-line with the water pipe. Click here for valve location
  6. Verify that the individual Cooling Water Shutoff Valves are all open and there is water flowing from each drain line.
  7. Open the Main Air Shutoff Valve (P10-V3). When open, the valve handle will be in-line with the air pipe. Click here for valve location
  8. Open the Ross Lockout Valve by pulling UP on the red handle. Click here for valve location
  9. Go to the Charge End HMI and push the MASTER START pushbutton.
  10. Once the computer has booted up, double-click on the Runtime System icon to bring up the Runtime System Title screen.
  11. Next, push (or click on) the F12 Main Menu button to display the Main Menu screen.
  12. Push the F1 Hand Mode button to place the Furnace in Hand Mode. "Hand Mode" will be displayed on the Status Bar.
  13. Push (or click on) the F14 Operator Functions button to display the submenu buttons.
  14. Then, push (or click on) the F15 Charge End Control button to display the Charge End Control 1 screen.
  15. Check to make sure the Inner Charge Door is in the Raised Position. If in the raised position, the block under the "WORK" column will be yellow. If the door is not raised, move it there now.
  16. Go to the Discharge End HMI and repeat the above steps to make sure the Inner Discharge Door is raised. If the door is not raised, move it there now.
  17. Remove any cables used to hold the Inner Charge and Discharge Doors open.

     This step must be performed by a Millwright.
  18. Open the rear peep doors.
  19. Go to the Charge End HMI and open the Outer Charge and Discharge Doors.
  20. Check inside the furnace to make sure its full of empties. If not, fill the furnace with empties now.
  21. Go to the Heating & Atmosphere Control Cabinet and push the black START COMBUSTION AIR BLOWER pushbutton. The yellow COMBUSTION AIR BLOWER ON indicator light illuminates.
  22. Next, push the black START ZONE 1 ROOF FAN, START ZONE 2 ROOF FAN, START ZONE 3 ROOF FAN and START ZONE 4 ROOF FAN pushbuttons to start the roof fans. The yellow ZONE 1 ROOF FAN ON, ZONE 2 ROOF FAN ON, ZONE 3 ROOF FAN ON and ZONE 4 ROOF FAN ON indicator lights illuminate
  23. Then, go the the Charge End HMI and start the exhaust fan.
  24. Move the Main Natural Gas Shutoff Valve (P1-V1) to the ON position by pulling the chain on the left-hand side of the valve down until the valve hits the mechanical stop. Click here for valve location
  25. Verify that the Burner Gas Shutoff Valve (P1-V5) is open. Click here for valve location
  26. Verify that the Natural Gas Test Valve is open (P1-V6). Click here for valve location
  27. Verify that the Vestibule Pilot Main Shutoff Valve (P1-V7) is open. Click here for valve location
  28. Verify that the Flame Curtain Main Shutoff Valve (P1-V8) is open. Click here for valve location
  29. Then, reset the Natural Gas Addition Pressure Low, Natural Gas Addition Pressure High, Main Burner Gas Pressure High and the Main Burner Gas Pressure Low pressure switches by pushing in the pin located on the side of each switch.
  30. Go to the Charge End Vestibule, light a Hand Torch and then push in and hold the OUTER CHARGE DOOR PILOT START pushbutton.

    The "CHARGE/DISCHRG. DOOR PILOT " switch / lamp placard names are reversed.
  31. While holding the pushbutton in, light the supervised door pilot (the one with the flame rod) with the Hand Torch. Once the OUTER CHARGE DOOR PILOT ON lamp turns on, release the "OUTER CHARGE DOOR PILOT START" pushbutton.
  32. Light the remaining Charge End Vestibule door pilot and stack pilot.
  33. Then, turn off the Hand Torch gas valve. Make sure the Hand Torch flame is extinguished.
  34. Next, go to the Discharge End Vestibule, light a Hand Torch and then push in and hold the OUTER DISCHARGE DOOR PILOT START pushbutton.

    The "CHARGE/DISCHRG. DOOR PILOT " switch / lamp placard names are reversed.
  35. While holding the pushbutton in, light the supervised door pilot (the one with the flame rod) with the Hand Torch. Once the OUTER DISCHARGE DOOR PILOT ON light turns on, release the OUTER DISCHARGE DOOR PILOT START pushbutton.
  36. Light the remaining Discharge End Vestibule door pilot and the stack pilot.
  37. Then, turn off the Hand Torch gas valve. Make sure the Hand Torch flame is extinguished.
  38. Go to the back of the furnace and light the two Peep Door pilots.
  39. Go to the Heating & Atmosphere Control Cabinet and turn all 4 Burner Igniter Selector switches to the SETUP position.
  40. Check each Zone Overtemperature instrument to make sure each is set to the correct setpoint as listed on the Process Control Sheet.
  41. Go to the Operational Control Cabinet and place each Zone Temperature Control instrument in Local Mode.
  42. Set the Zone Temperature Control instruments to a point below the current temperature so the burners will light in low-fire mode.
  43. Verify that the individual Zone Main Shutoff Valves are open.
  44. Next, open the Main Gas Maxon Valve (367 MRS) by rotating the valve lever 180° clockwise to latch the internal mechanism and then 180° counterclockwise to open the valve. Make sure that "OPEN" shows in the window on the front of the valve. Click here for valve location
  45. Check all burners to make sure they are lit. If any Burners are not lit, manually light them using the Hand Torch.
  46. Go to the Charge End HMI and close the Inner Charge and Discharge Doors.
  47. Go to the Heating & Atmosphere Control Cabinet and turn all 4 Burner Igniter selector switches to the NORMAL position.
  48. Then, set each Zone Temperature Control instrument to 575°F.
  49. Once the temperature in each Zone has reached to 575°F, hold it there for 1 hour.
  50. Next, start up the Salt Quench unit.
  51. Once the furnace has been held at 575°F for 1 hour, go to the Operational Control Cabinet and raise each Zone Temperature Control instrument to 930°F. Wait for the furnace to reach this temperature and then hold it there for 1 hour.
  52. Once the furnace has been held at 930°F for 1 hour, go to the Operational Control Cabinet and raise each Zone Temperature Control instrument to 1200°F. Wait for the furnace to reach this temperature and then hold it there for 1 hour.
  53. Set each Zone Temperature Control instrument to the correct Running Temperature per the Process Settings Sheet by pressing the Up Arrow key.
  54. Next, close the peep doors.
  55. Place a lit Hand Torch inside the Charge and Discharge vestibules.
  56. Wait until the temperature in each zone has reached 1425°F.

    Endothermic gas cannot be introduced into the furnace unless the temperature is above 1400°F. There are safety interlocks designed into the furnace to prevent this from happening.

    The Furnace temperature in all zones MUST be above 1400°F before continuing to the next step. Introducing Endothermic Gas below this temperature could result in an explosion. Do not rely solely on the temperature instrument readings. To be certain, look into the furnace to see that the heating chamber is a dark orange color.
  57. Once the temperature in each zone has reached 1425°F, go to the Operational Control Cabinet and verify that the Zone 2 and Zone 4 Carbon Controller selector switches are set to the ON position.
  58. Then, go to the Heating & Atmosphere Control Cabinet and set the Atmosphere Selector Switch to the ON position.
  59. Next, move the Endothermic Gas Main Shutoff Valve (P2-V12) to the open position. Click here for valve location
  60. Verify that the Endothermic Gas Leak Test Valve (P2-V13) is open. Click here for valve location
  61. Verify that the Endothermic/Nitrogen 3-Way Valve (P2-V16) is in the Endothermic Gas position. Click here for valve location
  62. Then, open the Endothermic Gas Maxon Valve (401MRS) by rotating the valve lever 180° clockwise to latch the internal mechanism and then 180° counterclockwise to open the valve. Make sure that "OPEN" shows in the window on the front of the valve. Click here for valve location
  63. Push the ALARM SILENCE pushbutton located on the Heating and Atmosphere cabinet. This must be done immediately after opening the Endothermic Gas Maxon Valve or it will automatically close after a programmed amount of time.
  64. Check the Endothermic Gas Flow Meter for Zone 1 and for Zones 2- 4 to make sure each is set to 500 CFH.
  65. Wait for the furnace to "burn in" before continuing to the next step. The furnace is considered burnt in once flames can be seen coming out from under the Inner Charge and Inner Discharge Doors. It may take up to a 1/2 hour to achieve"burn in".

    It is important to "burn in" the furnace to verify the presence of a positive pressure inside the furnace. This prevents the possibility of gas pockets forming inside the furnace or vestibules.
  66. Remove the Hand Torches from both vestibules and close the Outer Charge and Outer Discharge doors.
  67. Wait for the vestibules to "burn in". The vestibules are considered burnt in once flames can be seen coming out of both vestibule effluent stacks.
  68. Wait until the carbon content reading is above 0.70 before continuing onto the next step.
  69. Next, verify that the Additive Natural Gas Primary Shutoff Valve (P2-V14) is open. Click here for valve location
  70. Verify that the Additive Natural Gas Leak Test Valve (P2-V15) is open. Click here for valve location
  71. Then, open the Additive Natural Gas Maxon Valve (419MRS) by rotating the valve lever 180° clockwise to latch the internal mechanism and then 180° counterclockwise to open the valve. Make sure that "OPEN" shows in the window on the front of the valve. Click here for valve location
  72. Check the Natural Gas Flow Meters for Zone 2, Zone 3 and Zone 4 to make sure each is set to 25 CFH.
  73. Place each Zone Temperature Control instrument back into Remote Mode.
  74. Hold the furnace in this state for a minimum of 16 hours to properly "season" the furnace.

    The furnace must be properly "seasoned" to allow the carbon potential of the atmosphere to stabilize at a level suitable for process control.
  75. Next, start up the Pre-Wash unit.
  76. Then, start up the Pre-Rinse unit.
  77. Next, start up the Blowoff unit.
  78. Next, start up Temper Furnace 1 and 2.
  79. Go to the Transfer Car Control Panel and verify the E-stop button is pulled out.
  80. Then, push the TRANSFER CAR DRIVE MASTER START pushbutton.

    Make sure the Transfer Car is in the Home Position before starting.
  81. Make sure the TRANSFER CAR selector switch is in the AUTO position.
  82. Once the zone dew point readings are within the specifications listed on the Process Setting Sheet, begin loading Production Trays. Continue loading Production Trays until the first Production Tray completes the Quench Cycle.

    With the zone temperatures set for the process, two acceptable dewpoint measurements 1 hour apart must be recorded prior to parts entering the furnace.
  83. Once the first Production Tray completes the Quench Cycle, put the Furnace in the Hand Mode.
  84. Perform hardness testing on an Inspection Part from the first Production Tray.
  85. If the Inspection Part meets hardness specifications, place the Furnace back into Automatic Mode and resume production.

    If the Inspection Part does not meet hardness specifications, keep the Furnace in the "Hand Mode" and consult the DCP sheet for the corrective action to take. If the DCP corrective action does not correct the problem, contact the Metallurgical Engineer.