CHAPTER III.

BROWN COAL AS FUEL,—DIRECT FIRING WITH BROWN COAL, GAS FIRING WITH BROWN COAL,

The principal use of brown coal is, of course, for fuel purposes. Its proper and profitable application to this purpose has been brought about in three different ways. In the first place, by means of suitable appliances, it has been found possible to use the brown coal just as it comes from the mine for all kinds of domestic and manufacturing purposes. In the second place, by the preparation of an artificial fuel from it, it has been found possible to use it in the same manner and under the same conditions as bituminous coal. And in the third place, by the manufacture of producer gas from it, it has come into use in many metallurgical and manufacturing operations.

The most available fuel is that which can be used with least preliminary preparation. Hence we have such general use of wood and stone coal, even in localities where the same amount of heat could be obtained from fuel in other forms at the same or even less expense.

Therefore, in so far as it may be practicable, we should, where cheapness is the principal point, use the brown coal just as it comes from the mine.

If we consider the means of utilizing our brown coal raw, i. e., as it comes front the mines, without any preliminary preparation, we must observe the following facts:

First. The moisture it contains when freshly mined, and sometimes after long exposure to air, amounts even in the better brown coals, on an average, to about 11 per cent of their total weight, while that of the coals in use, as shown by analyses, is only 3 per cent. This surplus of 8 per cent must be evaporated by the heat evolved in the combustion of the brown coal, and lessens its fuel value to just that extent. Therefore we are confronted in the outset by the fact that under similar conditions a greater amount of raw brown coal will be required to accomplish a given amount of work than would be required with bituminous coal.