Patent GB-190317514-A (GB)
Title: Improvements in or in connection with the Manufacture of Peat Blocks for Fuel and in the Compression and Drying of other Substances
Inventor: THOMPSON WILLIAM PHILLIPS
Filed: 1903-08-12
Granted: 1903-10-08
Abstract: 17,514. Thompson, W. P., [White, F., and Griffin, G. A.]. Aug. 12. Moulding peat.-Relates to machines for the production of pressed and dried blocks in heated moulds, and mainly to the production of peat fuel blocks. Fig. 15 shows a fuel block produced by the machine. The process is characterized by the fact that the moulds, which are provided with drainage channels, are sufficiently highly heated to produce a hard matted tarry jacket on the exterior of the block, and that the pressure in the mould is applied by stages so as to give time for the formation of this layer before the pressure becomes very great. The loss of peat material through the drainage openings is thus prevented, without obstruction to the passage of moisture or steam. During the last stages of the moulding process, the applied pressure is not increased, and the shrinkage of the material causes a gradual reduction of the pressure in the mould, which prevents a rupture of the tarry jacket surrounding the block. Fig. 7 illustrates diagrammatically the type of multiple mould which is used in the machine. It comprises upper and lower sections D', D capable of sliding relatively to one another. The lower section is provided with upward extensions d, and the upper section with downward extensions d<1>. When the sections are moved in opposite directions, the faces d, d' approach one another, and the material is compressed. Fig. 9 shows a mould in section, the arrows indicating the approaching faces of the mould. The steam chambers in the walls D, D' are shown, and also the steam-heated tables B between which the moulds are moved when filled with peat. Narrow or slitlike drainage channels, indicated at B', pass through the steam-heated tables, and drainage channels are also formed in the walls of the mould. The machine is shown in perspective view in Fig. 1, and in partial vertical section in Fig. 5. The wet peat supplied to the hopper M fills the cavities M", and is discharged by cam-actuated pistons M<12> to tubes M'. The moulds D', D are brought beneath a transverse channel M<3> into which all the tubes M' open, and a hit-and-miss grid M<4> is moved by means of a handle M<5> to allow of the discharge of the peat to the moulds, the lower ends of which are closed by the table J<1>. When all the rows of mould cavities have thus been filled, the mould is pushed by the bars H<1> into the radial spaoe B" between two of the steam-heated tables B. The sliding tube d<6> communicates with a steam chest within the rotary mould-carrier A<3>, and supplies steam to the jackets of the mould. Fig. 5 shows the drainage channels B' and the spaces B<13> between the steam-heated tables for the passage of the water and steam issuing from the moulds. After a mould has been placed in position, the lever F<6> is depressed so as to actuate the hydraulic rams F', levers F, and ratchet E', and rotate the mouldcarrier through one step. The mould thus brought into position before the table J<1> is withdrawn by the bars H<1>, and the moulded peat blocks which it contains fall through the opening J. As each mould passes step-by-step from the charging point through one complete revolution, a fixed cam G<4> at each side of the machine actuates toggle-levers G' controlling pivoted levers G which act oppositely on the two sections of the mould so as to compress the material to a greater degree at each movement of the carrier. During the last few steps, no increase of pressure takes place, and during the last step, a pair of wedge surfaces pushes back the sections of the mould into the relative position indicated in Fig. 7, thus releasing the compressed blocks from all pressure. A valve B<4>, Fig. 5, fitted to each steam-heated table is opened automatically at the lowest point in the revolution, to permit condensed water to flow away. Electrical heaters may be used instead of steam jackets. The pistons M" have drainage apertures, and other apertures M<7>, covered with matting, in the tube M' also allow of the escape of water. The pressure devices need not be mounted on the rotating carrier, but can be secured to the machine so as to operate on the moulds at the desired points. Locking-devices are then used to hold the moulds in the positions to which they have been moved by the pressure devices.