Boiler maker Volume 9

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 Excerpt: ... the useful property of neutralizing harmful acids that are present in most feed waters, and, consequently, prevents corrosion and pitting. It is, however, imperative to know the exact quantity of soda ash to add in order to obtain the desired results. There must be neither lack nor excess of quantity, the latter causing priming and foaming. In stationary plants, where feed-water heaters are used, it has been found that oils, etc., used for lubricating purposes, enter into the boiler to some extent, and if soda ash is used in excess it saponifies (changes to soap) the oils. and again through galvanic action corrosion will set in. A Mysterious Boiler Explosion A 400-horsepower Wickes vertical boiler at the plant of the Denver Gas & Electric Company, Denver, Col., exploded on June I5, killing four, injuring six. and causing a property loss estimated at $75,000. The boiler had been out of commission for several days for repairs, and the explosion occurred just before cutting in the boiler again after the steam pressure had-been raised to about I50 pounds per square inch. The rupture occurred at the riveted joint between the bumped head of the lower drum and the shell of the drum. The drum was 8 feet in diameter, and the circular seam single riveted with I-inch rivets spaced 2% inches between centers. The shell plate was 9/16 inch thick, and the bottom head % inch thick. The shell plate ruptured between the rivet holes for almost the entire length of the seam. For the remaining distance the rivets sheared ofl'. All calculations seemed to indicatc that the boiler was amply strong for the pressure carried, and no signs of dangerous deterioration could be found. The following question was asked recently, a review of which, together with the answer given,...