The principles of colliery ventilation / [Alan Bagot].

  • Alan Charles Bagot
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: The principles of colliery ventilation / [Alan Bagot]. Source: Wellcome Collection.

    21/226 (page 5)
    In this way equilibrium is preserved. The elements of success, therefore, in furnace ventilation, are as follows:— The upcast shaft should be free from obstruction, the deeper of the two, and every pound of coal con- sumed in the furnace should do its share of work in setting the hot air column in motion; no more air should be admitted to the furnace than is absolutely necessary to support combustion, and the temper- atures in the two shafts should differ considerably, yet uniformly. Changes of temperature, or care- less firing, will check the air current, and this is to be avoided. We must consider, therefore, some of the laws which govern the mechanical properties and effect of heat, in order to proportion our furnace to our requirements. Coal is composed of carbon and hydrogen, and some other substances that are not necessary for our consideration. lbs. of coal require 29 cubic feet of air to insure complete combustion; this is on the supposition that the whole of the oxygen contained in the air is converted by combination with the carbon into carbonic acid gas; but in practice it will be found that the best furnaces only burn half the oxygen of the air passing through them, so double the amount of air must be provided. The process of burning is this: the greater part of the carbon is transformed into carbonic acid gas, the remainder into carbonic oxide : the hydrogen com-