Figs. 1 and 2 represent a plan and elevation of a bone-black room, containing light filters, A, arranged in a circle around wells, B. These latter have the form of a prism with trapezoidal base, whose small sides end at the same point, d, and the large ones at the filter. The funnel, E, of the washer, F, is placed in the space left by the small ends of the wells, so that the black may be taken from these latter and thrown directly into the washer. The washer is arranged so that the black may flow out near the steam fitter, G, beneath the floor. The discharge of this filter is toward the side of the elevator, H, which takes in the wet black below, and carries it up and pours it into the drier situated at the upper part of the furnace. This elevator, Figs. 3 and 4, is formed of two vertical wooden uprights, A, ten centimeters in thickness, to which are fixed two round-iron bars the same as guides. The lift, properly so-called, consists of an iron frame, C, provided at the four angles with rollers, D, and supporting a swinging bucket, E, which, on its arrival at the upper part of the furnace, allows the black to fall to an inclined plane that leads it to the upper part of the drier. The left is raised and lowered by means of a pitch-chain, F, fixed to the middle of the frame, C, and passing over two pulleys, G, at the upper part of the frame and descending to the mechanism that actuates it. This latter comprises a nut, I, acting directly on the chain; a toothed wheel, K, and a pinion, J, gearing with the latter and keyed upon the shaft of the pulleys, L and M. The diameter of the toothed wheel, K, is 0.295 of a meter, and it makes 53.4 revolutions per minute. The diameter of the pinion is 0.197 of a meter, and it makes 80 revolutions per minute. The pulleys, M and L, are 0.31 of a meter in diameter, and make 80 revolutions per minute. Motion is transmitted to them by other pulleys, N, keyed upon a shaft placed at the lower part, which receives its motion from the engine of the establishment through the intermedium of the pulley, O. The diameter of the latter is 0.385 of a meter, and that of N is 0.58. They each make 43 revolutions per minute.
FIG. 1.--ELEVATION OF BONE-BLACK REVIVIFYING PLANT (SCHREIBER'S SYSTEM.)
FIG. 2.--PLAN VIEW.
FIG. 3.--LATERAL VIEW OF ELEVATOR.
FIG. 4.--FRONT VIEW OF ELEVATOR.
FIG. 5.--CONTINUOUS FURNACE FOR REVIVIFYING BONE-BLACK.
The elevator is set in motion by the simple maneuver of the gearing lever, P, and when this has been done all the other motions are effected automatically.
The Animal Black Furnace.--This consists of a masonry casing of rectangular form, in which are arranged on each side of the same fire-place two rows of cast-iron retorts, D, of undulating form, each composed of three parts, set one within the other. These retorts, which serve for the revivification of the black, are incased in superposed blocks of refractory clay, P, Q, S, designed to regularize the transmission of heat and to prevent burning. These pieces are kept in their respective places by crosspieces, R. The space between the retorts occupied by the fire-place, Y, is covered with a cylindrical dome, O, of refractory tiles, forming a fire-chamber with the inner surface of the blocks, P, Q, and S. The front of the surface consists of a cast-iron plate, containing the doors to the fire-place and ash pan, and a larger one to allow of entrance to the interior to make repairs.
One of the principal disadvantages of furnaces for revivifying animal charcoal has been that they possessed no automatic drier for drying the black on its exit from the washer. It was for the purpose of remedying this that Mr. Schreiber was led to invent the automatic system of drying shown at the upper part of the furnace, and which is formed of two pipes, B, of undulating form, like the retorts, with openings throughout their length for the escape of steam. Between these pipes there is a closed space into which enters the waste heat and products of combustion from the furnace. These latter afterward escape through the chimney at the upper part.
In order that the black may be put in bags on issuing from the furnace, it must be cooled as much as possible. For this purpose there are arranged on each side of the furnace two pieces of cast iron tubes, F, of rectangular section, forming a prolongation of the retorts and making with them an angle of about 45 degrees. The extremities of these tubes terminate in hollow rotary cylinders, G, which permit of regulating the flow of the black into a car, J (Fig. 1), running on rails.
From what precedes, it will be readily understood how a furnace is run on this plan.
The bone-black in the hopper, A, descends into the drier, B, enters the retorts, D, and, after revivification, passes into the cooling pipes, F, from whence it issues cold and ready to be bagged. A coke fire having been built in the fire-place, Y, the flames spread throughout the fire chamber, direct themselves toward the bottom, divide into two parts to the right and left, and heat the back of the retorts in passing. Then the two currents mount through the lateral flues, V, and unite so as to form but one in the drier. Within the latter there are arranged plates designed to break the current from the flames, and allow it to heat all the inner parts of the pipes, while the apertures in the drier allow of the escape of the steam.
By turning one of the cylinders, G, so as to present its aperture opposite that of the cooler, it instantly fills up with black. At this moment the whole column, from top to bottom, is set in motion. The bone-black, in passing through the undulations, is thrown alternately to the right and left until it finally reaches the coolers. This operation is repeated as many times as the cylinder is filled during the descent of one whole column, that is to say, about forty times.