Boiler Maker Volume 18

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 edition. Excerpt: ...they are going to make some real tests. and a real test is when you run along about a week or a month. In a coal-fired furnace you have got, in the first place. to watch out for excess air. But when it comes to getting the ultimate and very maximum amount out of a given furnace, what you have got to watch out for in addition to that excess air is the carbon non-oxide, and there, unfortunately, the average analyzing rig don't show it correctly. As a rule, about-half a percent, sometimes as much as one percent, of carbon non-oxide will go right through the average gas analysis apparatus and will not be caught, because they do not get their solution, right. In furnace design, you have to get a furnace that will run up to, say, 13% or 14 percent of CO, with only a trace of CO, if you want to get the ultimate possibility. In a great many furnaces as soon as you get about 10 percent or II percent of your CO, and then try to cut down the excess air, you will find that you are running into the CO zone, so that practically I0 or 11 percent is the most economical point. On the other hand. if you get the furnace under certain conditions. it may be necessary to put air above the fire. It seems that in burning coal it is impossible to have an even fire bed over the bottom of the whole furnace, and with that even fire bed to have from every part of that fire bed a uniform analysis. Some part of your fire bed will give off volatile gases and CO. and other parts with the stokers. as we have them to-day. will give excess air; therefore you ha-'e got to get a furnace that has enough _volume. after _vou get through your fire bed, to mingle the gases. and also of a shape that will tend to mingle those gases aml burn them. if you want to get your very highest...