correct data available show that the radiation from uncovered two-inch
steam-pipe, with 60 pounds steam-pressure, is 391.83 kilo. centigrade
heat-units one foot one hour, or 21,739.78 kilos. of coal for 100 feet
per year of 300 days of 10 hours each; one kilo. equals 2,205 pounds.
Properly combining these figures we see that there are 23.97 tons of
coal lost by radiation from that uncovered pipe. If the coal costs $4
per ton, the radiation from this 100 feet of pipe will amount to $95.87.
From the same pipe covered with Wm. Berkefield's fossil meal
composition, 32/100-inch thick, the most powerful inorganic non-heat
conductor used as a covering at the time these investigations were made,
there was radiated 24,109 kilo. cent. heat-units one foot one hour, or
1,337.63 kilos. of coal for the year. This would be 1-474/1000 tons of
coal at $4 per ton, amounting to $5.89. Then $95.87 less $5.89 equals
$89.98, the saving effected by covering this pipe with William
Berkefield's fossil-meal composition 92/106 of an inch thick. Or, in
other words, the saving effected was over 93 per cent of the total
possible radiation, using a thickness of one inch this loss would be
reduced to $5.50.
From the same data we find (page 44) it stated that while the radiation
through 25 m.m. of Wm. Berkefield's fossil meal was 7.7 heat-units,
through 25 m.m. of carb. magnesia it was 6.7 heat-units, therefore the
proportions 7.7: 6.7 = $5.50: $4.80 gives us the coal value of heat lost
by radiation through the magnesia covering. To put this in another form:
From the running-foot of two-inch pipe uncovered the loss is 96 cents,
while, from the same pipe covered with the magnesia, the loss is less
than five cents; or a saving of over 91 cents per year. To accomplish
this saving the cost of the covering should be taken into account. This
was 27 cents. Therefore, the investment in the magnesia covering is paid
back in less than four months. The data which we have used were obtained
by the use of a calorimeter measuring the quantity of heat passing
through covering. The other possible method of arriving at this
knowledge would be to accurately measure the condensation of the steam.
In these experiments, owing to several reasons, it was not deemed
advisable to rely upon the second method. Recently, however, I have seen
in the _American Engineer_ of June 12, a report of the proceedings of
the Michigan Engineering Society containing a paper by Professor Coole
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