Industrial Engineering and the Engineering Digest Volume 1, No. 3 (Paperback)

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: ...under natural draft. Their construction is such that it would be difficult to operate in any other manner, as using forced draft would necessitate the closing entirely of the ashpit. Where conditions of driving and of the fuel are such that forced draft is required, other types of stoker may be better adapted to the work. This is one of the considerations we are proposing to take up in a later article. The chain grate stoker has been very successful in handling many of the bituminous coals of the western states. Installed in a Dutch oven, and driven at a rate not too greatly in excess of its normal capacity, it has operated at high economy, and with absolute smokelessness. While a Dutch oven or similar construction is desirable for a chain grate stoker, as it is for any type, in some cases it is not absolutely necessary and efficient service may be had without it. Whenever it is possible, however, it is advisable to install the Dutch oven, although it requires a width in front of the boiler of 6 to io feet above that required by a flush front boiler. Where conditions are such that the Dutch oven is not feasible, the alternative may be adopted of building an arch underneath the boiler, and above the stoker, or of suspending a set of tiles from the lower row of tubes in a water tube boiler, as is done in the Heine boiler. While it is often argued by those not entirely familiar with the principles of combustion, that the heating surface is reduced an undesirable amount by this construction, it is nevertheless true that the resulting better combustion and the higher temperature of the gases more than compensate for the reduced heating surface. The writer once conducted a series of tests on two boilers, one of which was fitted with a fire brick arch under the bo...