At the bottom of the kiln is a grate of iron bars, and on this wood and coke are piled to start the fire.
The maximum rate of combustion may be as much as so lb of coal per square foot of grate per hour, and in exceptional cases even a greater rate than this has been maintained.
The open grate still holds favour in England, though in America and on the continent of Europe it has been superseded by the closed stove.
Per pound, the maximum indicated horse-power is given by the expression I.H.P. maximum - CcA X778 1980000 where A is the area of the grate in square feet, and is the combined efficiency of the engine and boiler.
Graphite is used for the manufacture of pencils, dry lubricants, grate polish, paints, crucibles and for foundry facings.
The size of the grate varies with the requirements of the ventilation, but from 6 to io ft.
I had soon read all the tracts that were left there, and examined where former prisoners had broken out, and where a grate had been sawed off, and heard the history of the various occupants of that room; for I found that even here there was a history and a gossip which never circulated beyond the walls of the jail.
It has many advantages for heavy high-speed service, namely, large and well-proportioned boiler, practically unlimited grate area, fire-box of favourable proportions for firing, fairly low centre of gravity, short coupling-rods, and, finally, a combination of the safe and smooth riding qualities of the fourcoupled bogie type, with great steaming capacity and moderate axle loads.
If C is the number of pounds of coal burnt per square foot of grate per hour, the calorific value of which is c B.Th.U.
The Chimney Section Grate Drying space for Slurry Plan FIG.