Evening Republican, Volume 18, Number 71, Rensselaer, Jasper County, 24 March 1914 — BLOWING OUT BOILER TUBES [ARTICLE]

BLOWING OUT BOILER TUBES

Much Gain in Fuel Economy Proved to Be Had by Following This Method.

Tests have demonstrated that five to ten per cent, gain in fuel economy may be obtained through the regular blowing of soot from boiler tubes. Soot Interposes additional resistance to the flow of heat, and its removal increases the coefficient of heat transmission and thus reduces the flue gas temper*ture.

If boiler surface is maintained free of soot and the superheater surface neglected there will be only a small excess temperature of waste gases, because the superheater surface is only a small per cent of the total, says the Boilermaker. But there is a decided loss in econo-, my, because the superheater temperature will be very much less than that to be obtained with clean superheated tubes. It is quite possible for superheater tubes to be so covered with soot as to reduce the superheater temperature 50 degrees below normal, equivalent to five per cent, or more excess steam consumption. Ordinarily boiler and superheater surface should be blown a number of times a day, and if this course is pursued the duration of biowing need be very short.

The superheater blower is first operated, the soot being carried by the draft into the boiler setting, from which it flows to the up-take. Such parts of the soot as are redeposited in the boiler are then dislodged when the boiler is blown.

In order to insure regularity in the blowing of the superheater and boiler surface, also in blowing off muddrums, it is a good plan to rig up some automatic device, which will record the time at which soot blowers and mud-drum blow-offs are operated.