Document EqxqyMd596wJODpq3p8kML8Dg

Am. Soc. of Heat.-Vent. Engineers Guide, 1922 87 In determining r,, the author derives the equation for any isothermal' ground at the distance r which will have the temperature t. '8 *f U log - log -- rx Fig. 3 shows similar curves for a pipe covered with 1 in. infusorial earth buried deeply in the ground for steam temperature of 225 deg. fahr. with a conductivity factor of 0.04 for the covering. Depth of Center orf Pipe from Ground Surfaced Feet) Fig. 5 shows the effect of burying pipes at different depths and shows' that below 2 ft. there is little effect on the heat loss. Fig. 4 shows heat losses for various thickness of covering for a 3 in. pipe buried deeply in the ground; using for the basis for calculation, T~225, K = 0.89 for wet earth and 0.212 for dry earth and a conductivity factor of 0.04 for covering material. The curves show that for wet ground, the heat loss reduces very rapidly as the thickness of the covering increases up to 2 in. and from 2 in. up, the increase is quite gradual. For dry ground, the effect of increasing the thickness of covering, is much mdre gradual and above V/z in. it becomes almost nothjngj Fig. 6 shows the relation of coverings of different conductivity to the heat loss in dry and wet ground.