Fig. 2838.
[Fig. 2838] represents a side draft forge. f is the fireplace, usually from 3 to 5 feet long, t is the tuyère through which the blast enters the fire, b being the blast pipe. To prevent t from being burned away it is hollow as at s, and two pipes p and p′ connect to the water-tank w, thus maintaining a circulation of water through s; v is simply a valve or damper to shut off the supply of air from the tuyère; d is the opening to the chimney c.
The side blast, though not so much used as in former years, is still preferred by many skilful mechanics, on the ground that it will give a cleaner fire with less trouble. The method of accomplishing this is to dig out a hole in the fire bed and fill it in with coked coal, which will form a drain through which the slag or clinker may sink, instead of remaining in the active fire and obstructing the blast.
In cases where the fire requires to be built farther out from the chimney wall than the location of the tuyère permits, it may be built out as follows:—
Fig. 2839.
Fig. 2840.