Bulletin . nests of tubes. It seems thenthat no amount of care taken in firing smoky fuels in this t^^pe offurnace will produce smokeless combustion. The points of the same group show that the tendency of a coalto smoke is not reduced by briquetting the fuel; in fact it is shownthat rather more smoke was made with briquetted than with run-of-mine coal. The high percentage of black smoke made with thelarge briquets is partly due to a smaller supply of air, as is sho^vnby the lowest group of points in figure 4. The points of the upper group of figure 5 show the amount offlaming observed above th
Bulletin . nests of tubes. It seems thenthat no amount of care taken in firing smoky fuels in this t^^pe offurnace will produce smokeless combustion. The points of the same group show that the tendency of a coalto smoke is not reduced by briquetting the fuel; in fact it is shownthat rather more smoke was made with briquetted than with run-of-mine coal. The high percentage of black smoke made with thelarge briquets is partly due to a smaller supply of air, as is sho^vnby the lowest group of points in figure 4. The points of the upper group of figure 5 show the amount offlaming observed above the stack. Every time the smoke observerread smoke he also made a note of flaming above the stack whenthe same was observable. The upper ordinate of figure 5 representsthe number of times flame was observed above the stack expressedas a percentage of total smoke readings. It is shown that there wasmore flaming with either style of briquet than with run-of-mine coal. DATA AND CALCULATIONS SHOWN GRAPHICALLY. 27. 0 10 ZO 30 40 50 60 70 80 90 Pounds of dry coal fired per hour per square foot of grate surface FiGtniE 5.—Effect of increasing rate of combustion on name observations as a percentage of totalnumber of smoke observations (above) and percentage of black smoke (below). 28 TESTS OF COALS AND BRIQUETS OX TORPEDO BOAT. ON DISTRIBUTION OF HEAT. Figure 6 and the two lower groups of points of figure 7 show howthe distribution of the heat of the combustible ascending fromthe grate varied with the rate of combustion. All heat quantitiesin these two figures are expressed in percentage of the total heat in^combustible ascending from grate. ON HEAT LOSSES. The points grouped at the top of figure 6 represent the heat carried•up the stack in the moisture formed by burning of hydrogen andalso in the free moisture in the coal (item 2 + item 3 in the heatbalance). The points show that the heat loss due to moisture inthe flue gases is very nearly the same for all rates of
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectminesandmineralresou
