by Pete in Holland MI » August 13, 2014, 12:53 pm
I have no experience firing a freighter, but I do own a 102 year old steam tractor and on occasion, do fire with coal. My grates are small by comparison to a freighter (26" x 44").
The phrase passed on to me is to "fire little, fire often". To burn correctly and cleanly, the grates need to be kept covered with 2-3" of coal (golf ball size). Too little and a dark spot appears due to the coal burned up and the grates showing, letting cold air thru. Dark spots can also come from too much coal, and it won't burn properly, and just smolder, thus produce little heat. This requires doing a quick check every time coal is added, and to only add to those areas needing it.
The grates need to be sliced (compare to a spatula sliding under the coal fire) to break up the klinkers, which will seal up the grate surface and reduce combustion air flow thru the grates. This happens every half hour or so.
Ash levels under the grates need to be maintained too. Too many ashes that are allowed to raise up and touch the grates will cut off the underside cooling air, causing grates to overheat and warp. Too often, I see fireplace grates that have suffered this same result.
With a good induced draft and properly managed fire, the smoke is nearly transparent. Shut the engine down till it naturally burns, and smokes something fierce.
Ships, for the most part, are naturally aspirated, sometimes helped with a blower, or sometimes, a pressurized boiler room. Increasing the air flow to the fire makes it burn hotter and, if properly managed, cleaner.
A good burning coal fire is indensely hot. Far hotter than a wood fire. Standing in front of an open firebox door wears you down very quickly.
Hope this helps some......
Pete
I have no experience firing a freighter, but I do own a 102 year old steam tractor and on occasion, do fire with coal. My grates are small by comparison to a freighter (26" x 44").
The phrase passed on to me is to "fire little, fire often". To burn correctly and cleanly, the grates need to be kept covered with 2-3" of coal (golf ball size). Too little and a dark spot appears due to the coal burned up and the grates showing, letting cold air thru. Dark spots can also come from too much coal, and it won't burn properly, and just smolder, thus produce little heat. This requires doing a quick check every time coal is added, and to only add to those areas needing it.
The grates need to be sliced (compare to a spatula sliding under the coal fire) to break up the klinkers, which will seal up the grate surface and reduce combustion air flow thru the grates. This happens every half hour or so.
Ash levels under the grates need to be maintained too. Too many ashes that are allowed to raise up and touch the grates will cut off the underside cooling air, causing grates to overheat and warp. Too often, I see fireplace grates that have suffered this same result.
With a good induced draft and properly managed fire, the smoke is nearly transparent. Shut the engine down till it naturally burns, and smokes something fierce.
Ships, for the most part, are naturally aspirated, sometimes helped with a blower, or sometimes, a pressurized boiler room. Increasing the air flow to the fire makes it burn hotter and, if properly managed, cleaner.
A good burning coal fire is indensely hot. Far hotter than a wood fire. Standing in front of an open firebox door wears you down very quickly.
Hope this helps some......
Pete