Furthermore, addition of water is not only unnecessary in any case, but the peat may be advantageously air-dried to a considerable extent before it enters the machine. Wet peat is, indeed, worked with less expenditure of power; but the moulded peats are then so soft as to require much care in the handling, and must be spread out in single courses, as they will not bear to be placed one upon another. Peat, that is somewhat dry, though requiring more power to work, leaves the machine in blocks that can be piled up on edge and upon each other, six or eight high, without difficulty, and require, of course, less time for curing.
The cut, (fig. 18), represents one of Schlickeysen's portable peat-mills, with elevator for feeding, from which an idea of the pulverizing arrangements may be gathered.
In Livonia, near Pernan, according to Leo, two of Schlickeysen's machines, No. 6, were put in operation upon a purely fibrous peat. They were driven by an engine of 12 horse-power. The peat was plowed, once harrowed, then carted directly to the hopper of the machine. These two machines, with 26 men and 4 horses, produced daily 60,000 peats = 7500 cubic feet. 100 cubic feet of these peats were equal in heating effect to 130 cubic feet of fir-wood, and cost but two-thirds as much. The peats were extremely hard, and dried in a few days sufficiently for use. In 1864, five large Schlickeysen machines were in operation at one establishment at St. Miskolz, in Hungary.
The smaller sizes of Schlickeysen's machine are easily-portable, and adapted for horse or hand-power.
Leavitt's Peat-condensing and Moulding Mill.[27]—In this country, Mr. T. H. Leavitt, of Boston, has patented machinery, which is in operation at East Lexington, Mass., at the works of the Boston Peat Company. The process is essentially identical with that of Weber, the hot-drying omitted. The fresh peat is pulverized or cut fine, moulded into blocks, and dried on light frames in the open air. The results claimed by Mr. Leavitt, indicate, that his machine is very efficacious.
It consists, principally, of a strong box or cistern, three feet in diameter, and six feet high, the exterior of which, with its gearing, is shown in figure 19. The mill is adapted to be driven by a four horse-power engine.
"The upper portion of the box is divided by a series of horizontal partitions, the upper ones being open latticework, and the lower ones perforated with numerous holes. The upright shaft, which rotates in the centre of the box, carries a series of arms or blades, extending alternately on opposite sides, and as these revolve, they cut the peat, and force it through the openings in the diaphragms. The lower portion of the box, in place of complete partitions, has a series of corrugated shelves extending alternately from opposite sides, and the peat is pressed and scraped from these by a series of arms adapted to the work. By this series of severe operations the air-bubbles are expelled from the peat, and it is reduced to a homogeneous paste. When it arrives at the bottom of the box, it is still further compressed by the converging sides of the hopper, and it is received in light moulds which are carried on an endless belt." Mr. Leavitt has patented the use of powdered peat for the purpose of preventing the prepared peat from adhering to the moulds.
Fig. 19.—LEAVITT'S PEAT MILL.
This mill, it is asserted, will condense 40 tons of crude peat daily, which, at Lexington, is estimated to yield 10 to 14 tons of dry merchantable fuel. The cost of producing the latter is asserted to be less than $2.00 per ton; while its present value, in Boston, is $10 per ton. It requires seven men, three boys, and two horses to dig, cart, mill, and spread the peat. The machine costs $600, the needful buildings, engine, etc., from $2000 to $3000. The samples of peat, manufactured by this machine, are of excellent quality. The drying in the open air is said to proceed with great rapidity, eight or ten days being ordinarily sufficient in the summer season. The dry peat, at Lexington, occupies one-fourth the bulk, and has one-fourth to one-third the weight of the raw material; the latter, as we gather, being by no means saturated with water, but well drained, and considerably dry, before milling.