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#BoilerManual #OptimizingCombustion #Section9 #Page21
produced runs out the cyclone, down the furnace, and into the lag tank, for final disposal.
6. The five requirements necessary for slag tap furnaces are:
........ 1. The furnace must be able to maintain temperatures above 3000 F and also be able to tolerate these temperatures.
........ 2. The slag tap furnace must be strong enough to support the extremely heavy molten slag, wherever it tends to accumulate.
........ 3. ___The wall of the furnace should be chemically inactive to the hot slag.
........ 4. ___There must be adequate drainage for the slag.
........ 5. ___The slag needs to be cooled for disposal.
7. The three materials in coal are:
........ 1. ___Combustible material, which should be 15% for cyclone furnaces.
........ 2. ___Ash, which should be a minimum
........ 3. ___Moisture.
8. The four steps that can help prevent iron sulfide formation are:........ 1. ___Make sure the cyclones are getting enough excess air.
........ 2. ___Keep coal sizing as fine as possible.
........ 3. ___Keep iron oxides to a minimum by making sure cyclone firing is balanced at all times.
........ 4. ___Protect tube surfaces from iron sulfides by keeping stud length at least 1/4" or longer, and by using a good refractory coating that will last.
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#BoilerManual #OptimizingCombustion #Section9 #Page21
produced runs out the cyclone, down the furnace, and into the lag tank, for final disposal.
6. The five requirements necessary for slag tap furnaces are:
........ 1. The furnace must be able to maintain temperatures above 3000 F and also be able to tolerate these temperatures.
........ 2. The slag tap furnace must be strong enough to support the extremely heavy molten slag, wherever it tends to accumulate.
........ 3. ___The wall of the furnace should be chemically inactive to the hot slag.
........ 4. ___There must be adequate drainage for the slag.
........ 5. ___The slag needs to be cooled for disposal.
7. The three materials in coal are:
........ 1. ___Combustible material, which should be 15% for cyclone furnaces.
........ 2. ___Ash, which should be a minimum
........ 3. ___Moisture.
8. The four steps that can help prevent iron sulfide formation are:........ 1. ___Make sure the cyclones are getting enough excess air.
........ 2. ___Keep coal sizing as fine as possible.
........ 3. ___Keep iron oxides to a minimum by making sure cyclone firing is balanced at all times.
........ 4. ___Protect tube surfaces from iron sulfides by keeping stud length at least 1/4" or longer, and by using a good refractory coating that will last.
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#BoilerManual #Ramping #Section8 #Page21
Again, the major problem with this ramp was the failure to establish proper pre-ramp conditions at the CP and PSH outlets. Had the proper temperatures been established and the boiler stable, the 207 valve would have been far enough open to compensate for the initial opening of the 201 valves and PSH outlet temperature would not have dropped. The resultant overfiring early in the ramp to raise that temperature could have been avoided.
The overfiring at the end of the ramp could also have been avoided if the firing rte had been reduced rather than increased, as the increasing CP and PSH temperatures indicated it should have been. Graphs in the control room of the proper firing rate, MW, and throttle pressure for each boiler master position certainly would have helped in avoiding this problem. {Such graphs were found in the control room at Baldwin for each unit, plotted out in real time via chart recorders. These gizmos consisted of an overhead ink pen tip touching a rather long scroll of graph paper loaded into them.}
You should now be able to understand the importance of maintaining proper pre-ramp conditions. The ramping process depends on the operation of many valves to maintain proper pressures and temperatures throughout the system for safe and efficient startups. A timely and orderly startup from bypass to ramping requires complete understanding of the operation of each valve and its function with the boiler cycle.
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#BoilerManual #Ramping #Section8 #Page21
Again, the major problem with this ramp was the failure to establish proper pre-ramp conditions at the CP and PSH outlets. Had the proper temperatures been established and the boiler stable, the 207 valve would have been far enough open to compensate for the initial opening of the 201 valves and PSH outlet temperature would not have dropped. The resultant overfiring early in the ramp to raise that temperature could have been avoided.
The overfiring at the end of the ramp could also have been avoided if the firing rte had been reduced rather than increased, as the increasing CP and PSH temperatures indicated it should have been. Graphs in the control room of the proper firing rate, MW, and throttle pressure for each boiler master position certainly would have helped in avoiding this problem. {Such graphs were found in the control room at Baldwin for each unit, plotted out in real time via chart recorders. These gizmos consisted of an overhead ink pen tip touching a rather long scroll of graph paper loaded into them.}
You should now be able to understand the importance of maintaining proper pre-ramp conditions. The ramping process depends on the operation of many valves to maintain proper pressures and temperatures throughout the system for safe and efficient startups. A timely and orderly startup from bypass to ramping requires complete understanding of the operation of each valve and its function with the boiler cycle.
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#BoilerManual #BypassSystem #Section7 #Page21
8. What is the ramping stage of boiler startup?
9. When can the hot cleanup phase be eliminated from the startup procedure?
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#BoilerManual #BypassSystem #Section7 #Page21
8. What is the ramping stage of boiler startup?
9. When can the hot cleanup phase be eliminated from the startup procedure?
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#BoilerManual #CycloneOperation #Section6 #Page21
Questions for cyclone operation
1. Name the four stages involved in cyclone startup.
.......... 1. ________________________________
.......... 2. ________________________________
.......... 3. ________________________________
.......... 4. ________________________________
2. How is air flow to the boiler controlled, during the purge stage?
3. What are the five boiler firing permissives necessary for cyclone startup?.......... 1. ________________________________
.......... 2. ________________________________
.......... 3. ________________________________
.......... 4. ________________________________
.......... 5. ________________________________
4. What happens in the cyclone when the lighter start button is pushed?5. What happens in the cyclone when the cyclone start button is pushed?
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#BoilerManual #CycloneOperation #Section6 #Page21
Questions for cyclone operation
1. Name the four stages involved in cyclone startup.
.......... 1. ________________________________
.......... 2. ________________________________
.......... 3. ________________________________
.......... 4. ________________________________
2. How is air flow to the boiler controlled, during the purge stage?
3. What are the five boiler firing permissives necessary for cyclone startup?.......... 1. ________________________________
.......... 2. ________________________________
.......... 3. ________________________________
.......... 4. ________________________________
.......... 5. ________________________________
4. What happens in the cyclone when the lighter start button is pushed?5. What happens in the cyclone when the cyclone start button is pushed?
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#BoilerManual #CycloneDescription #Section5 #Page21
9. Low viscosity coal is best suited for low loads conditions. It requires lower temperatures for adequate slag tapping.
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#BoilerManual #CycloneDescription #Section5 #Page21
9. Low viscosity coal is best suited for low loads conditions. It requires lower temperatures for adequate slag tapping.
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#BoilerManual #Lighters #Section4 #Page21
Answers for Mark IV Oil Lighters
1. The main purpose of the lighter is to provide ignition of the main fuel when a burner is placed in-service.
2. The three secondary purposes of the lighter are to:
..........1. __stabilize ignition at low loads.______________________
..........2. __warm the furnace prior to placing the burner in-service___
..........3. __sustain ignition for as long as possible when a burner is removed from service.3. The answer is False[/b]. Under no circumstances should the lighter be used to carry load.
4. The igniter spark gap shoud be set at 1/8" for peak performance.
5. The answer is [i]False. You can control the lighter's speed of travel by adjusting the speed control valve on the exhaust side of the air cylinder
6. The three operating conditions are:
..........1. __Light-off_____________________
..........2. __Normal shutdown______________
..........3. __Emergency shutdown___________
7. During a normal lighter shutdown, the oil is turned off, the oil lines are purged with air for one to three minutes, the ignition transformer is de-energized and the lighter is retracted.8. The atomizer should always be cleaned with a solvent and never scraped.
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#BoilerManual #Lighters #Section4 #Page21
Answers for Mark IV Oil Lighters
1. The main purpose of the lighter is to provide ignition of the main fuel when a burner is placed in-service.
2. The three secondary purposes of the lighter are to:
..........1. __stabilize ignition at low loads.______________________
..........2. __warm the furnace prior to placing the burner in-service___
..........3. __sustain ignition for as long as possible when a burner is removed from service.3. The answer is False[/b]. Under no circumstances should the lighter be used to carry load.
4. The igniter spark gap shoud be set at 1/8" for peak performance.
5. The answer is [i]False. You can control the lighter's speed of travel by adjusting the speed control valve on the exhaust side of the air cylinder
6. The three operating conditions are:
..........1. __Light-off_____________________
..........2. __Normal shutdown______________
..........3. __Emergency shutdown___________
7. During a normal lighter shutdown, the oil is turned off, the oil lines are purged with air for one to three minutes, the ignition transformer is de-energized and the lighter is retracted.8. The atomizer should always be cleaned with a solvent and never scraped.
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#BoilerManual #AirAndGasFlow #Section3 #Page21
While others have insufficient air to burn the fuel flowing through them. The total air flow to each cyclone is the sum of the secondary, primary and tertiary air.
SECONDARY AIR FLOW MEASUREMENT
Secondary air flow is measured on an individual cyclone basis. The differential pressure required to measure air flow is created by a bellmouth arrangement located at the secondary air inlet to the cyclone, Figure 16. A perforated screen which covers the bellmouth opening functions to distribute the air flow in a more uniform manner.
Secondary air flow calibration should be done at the bellmouth at three different air flows to check that equal secondary air flows are obtained
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Alt = Labeled Fig. 15 Percent of O2 in flue gas vs. excess air (dry basis). Graph is laid out in terms of percentage on both axes; X axis is marked Percent of O2 in flue gas (by volume) incremented every 2%, up to 12%. Y axis is marked Percent excess air--incremented every 20% up to 100. There are 2 curves on the graph, one in solid line and the other in dashed line. They both beginat the graph's origin point, going slightly upward but diverge when 2% flue gas O2 is reached. The solid line goes higher than the dashed line only slightly and converge again at the upper right corner area. The solid line is marked Sub-bituminous while the dashed line is marked Bituminous. -
#BoilerManual #AirAndGasFlow #Section3 #Page21
While others have insufficient air to burn the fuel flowing through them. The total air flow to each cyclone is the sum of the secondary, primary and tertiary air.
SECONDARY AIR FLOW MEASUREMENT
Secondary air flow is measured on an individual cyclone basis. The differential pressure required to measure air flow is created by a bellmouth arrangement located at the secondary air inlet to the cyclone, Figure 16. A perforated screen which covers the bellmouth opening functions to distribute the air flow in a more uniform manner.
Secondary air flow calibration should be done at the bellmouth at three different air flows to check that equal secondary air flows are obtained
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Alt = Labeled Fig. 15 Percent of O2 in flue gas vs. excess air (dry basis). Graph is laid out in terms of percentage on both axes; X axis is marked Percent of O2 in flue gas (by volume) incremented every 2%, up to 12%. Y axis is marked Percent excess air--incremented every 20% up to 100. There are 2 curves on the graph, one in solid line and the other in dashed line. They both beginat the graph's origin point, going slightly upward but diverge when 2% flue gas O2 is reached. The solid line goes higher than the dashed line only slightly and converge again at the upper right corner area. The solid line is marked Sub-bituminous while the dashed line is marked Bituminous. -
#BoilerManual #FluidCirculation #Section2 #Page21
..........Note: Beginning at the neck circuit for any given cyclone, continue
.....................down through the sequence and replace the lower circuits with
.....................one(s) from above. Example: Starting at the neck for cyclone
.....................B4, flow is to the barrel circuits of B2, A1, A3, A5, A7 and out the
.....................re-entrant throat of B6.Furnace Circulation
Furnace supplies taken from the cyclone discharge mix bottle feed three separate circuits; the front, rear, and sidewalls. These furnace circuits are subdivided into various passes in between which mix bottles are located. As with the cyclone discharge mix bottle, the purpose of these bottles is to balance the fluid temperature entering the following circuit in order to compensate for unbalanced heat inputs. Refer to Figure 18 as the furnace flow paths are described.
FURNACE FRONT AND REAR WALL TUBES
Supplied by the cyclone discharge and mix bottles (Figure 19), the lower furnace front and rear wall headers feed the furnace floor tubes. These floor tubes bend to form the slag neck and the furnace floor. From the furnace floor, flow is straight up the front and rear walls until bends are made to form the furnace wall openings at the cyclones.
Vertical flow continues until the first pass mix headers and bottles are reached (Figure 20). The front and rear furnace wall tubes are collected in the first pass outlet header and sent to a mix bottle. The mix bottle insures a uniform fluid temperature entering the second pas inlet header.
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#BoilerManual #FluidCirculation #Section2 #Page21
..........Note: Beginning at the neck circuit for any given cyclone, continue
.....................down through the sequence and replace the lower circuits with
.....................one(s) from above. Example: Starting at the neck for cyclone
.....................B4, flow is to the barrel circuits of B2, A1, A3, A5, A7 and out the
.....................re-entrant throat of B6.Furnace Circulation
Furnace supplies taken from the cyclone discharge mix bottle feed three separate circuits; the front, rear, and sidewalls. These furnace circuits are subdivided into various passes in between which mix bottles are located. As with the cyclone discharge mix bottle, the purpose of these bottles is to balance the fluid temperature entering the following circuit in order to compensate for unbalanced heat inputs. Refer to Figure 18 as the furnace flow paths are described.
FURNACE FRONT AND REAR WALL TUBES
Supplied by the cyclone discharge and mix bottles (Figure 19), the lower furnace front and rear wall headers feed the furnace floor tubes. These floor tubes bend to form the slag neck and the furnace floor. From the furnace floor, flow is straight up the front and rear walls until bends are made to form the furnace wall openings at the cyclones.
Vertical flow continues until the first pass mix headers and bottles are reached (Figure 20). The front and rear furnace wall tubes are collected in the first pass outlet header and sent to a mix bottle. The mix bottle insures a uniform fluid temperature entering the second pas inlet header.
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@Su_G #BoilerManual #UnitDescription #Section1 #Page21
Questions for unit description
1. What are the five material flow paths in your boiler?
..........1. _____________________________________..........2. _____________________________________
..........3. _____________________________________
..........4. _____________________________________
..........5. _____________________________________
2. What is the purpose of the full-studded tubes in the cyclone?
3. What is the purpose of gas recirculation?
4. How is the combustion of coal achieved in the cyclone furnace?
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@Su_G #BoilerManual #UnitDescription #Section1 #Page21
Questions for unit description
1. What are the five material flow paths in your boiler?
..........1. _____________________________________..........2. _____________________________________
..........3. _____________________________________
..........4. _____________________________________
..........5. _____________________________________
2. What is the purpose of the full-studded tubes in the cyclone?
3. What is the purpose of gas recirculation?
4. How is the combustion of coal achieved in the cyclone furnace?
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