Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
  • B30B11/22—Extrusion presses; Dies therefor
  • B30B11/26—Extrusion presses; Dies therefor using press rams
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
  • B30B11/22—Extrusion presses; Dies therefor
  • B30B11/227—Means for dividing the extruded material into briquets

Definitions

• This invention relates to a machine for the pressing of pellets, including a block having an upwardly open flute and a plurality of long narrow bores mouthing in the flute, which bores are open at opposite ends and in which pistons are movable to-and-fro, more precisely between a first end position in which a front end of the individual piston is withdrawn while uncovering a bottom space in the flute so that fine-grained raw material can fall down therein, and a second, fully extended end position in which the front end of the piston has been inserted a bit in an appurtenant bore so as to compress the raw material therein to a continuous string which may be fed out of the bore via an outlet opening.
• Pellets for combustion purposes are usually made of sawdust or other fine wooden components, possibly with addi- tives of binding agents or the like.
• Previously known machines for such manufacture of pellets consist of rotatable, cylindric drums into which the raw material is fed axially in order to be fed out via radial holes in the cylinder wall of the drum.
• a disadvantage of these machines is, however, that the degree of compression or compactness of the finished pellet bodies becomes mediocre. More precisely, the pellet bodies get such a loose internal structure that the sausage-like strings which are fed out via said radial hole are broken up automatically, considerable amounts of dust being released in the surfaces of rupture.
• a primary object of the invention is to provide a machine which is small and structurally simple and, therefore, inexpensive to manufacture and use, and which gives pellet bodies with a compact, dense internal structure, which do not give rise to appreciable dust formation neither in connection with the actual manufacture nor during the subsequent handling before combustion.
• Another object of the invention is to create a machine, which in spite of constructive simplicity, should have a high capacity at the same time as it will require a minimum of energy.
• a machine of the type defined in the preamble is pre- viously known by DE 350 619.
• the pistons included in this machine lack pins on the free ends thereof, and therefore the machine can not bring about pellets with the compact density being attained by means of the machine according to the invention.
• the known machine include a cutting device arranged after the block for cutting fed-out, extremely resistant material strings. For these reasons, the known machine is not suitable for the manufacture of compact pellet bodies .
• Fig 1 is a partly cut side view showing a machine according to the invention in its entirety
• Fig 2 is a partial planar view from above showing a driving mechanism included in the machine
• Fig 3 is a partial perspective view showing a block being characteristic for the invention included in the machine
• Fig 4 is a longitudinal section showing said block together with a piston movable in a bore of said block, the piston being in a first end position before a pressing operation
• Fig 5 is an analogous longitudinal section showing the same piston in a second end position after performing a pressing operation
• Fig 6 is a partly cut planar view from above of the block according to fig 3-5
• Fig 7 is an enlarged section showing the nature of an indi- vidual bore included in the block
• Fig 8 is a partial perspective view illustrating the structure of a raw material string formed in a bore
• Fig 9 is a perspective view illustrating a number of pellet bodies ready-made in the machine.
• the machine shown in fig 1 and 2 comprises a carrying table or stand 1 on which there is a stand 2 for a block 3 and a movable slide 4 which is movable to-and-fro via a driving mechanism designated 5 in its entirety.
• mechanism 5 includes a crank 6, one end of which is articulatedly connected to the slide 4, and the opposite end of which is journalled in an eccentric body 7, which is rigidly connected to a rotatable shaft 8 to which a balance wheel 9 is also connected.
• the shaft 8 is rotatable by means of a motor
• a transmission 11 in the form of a chain, a synchronous drive ' belt or the like.
• An upwardly open pocket 13 in which raw material may be tapped from above is mounted on a carrier 12.
• a conveying screw 14 4 acts in the bottom of the pocket by means of which screw the raw material 15 may be fed out over and fall down into a funnel construction 16.
• the funnel construction 16 is mounted on top of a depth 17 in the top side of the block 3.
• the shaft 19 together with the appurtenant wing 20 is rotatable by means of a second transmission 11' that is connected to the shaft 8.
• the shafts 19 and 8 are rotatable by means of one and the same driving source, viz . the motor 10.
• the block 3 is of a parallelepipedical basic shape and has an upwardly open flute 21.
• a plurality of mutually separated bores, generally designated 23, are recessed in the portion of the block extending between the flute 21 and a rear end surface 22. More precisely, each individual bore 23 extends perpendicularly towards the flute 21 and has opposite openings or mouths 24 and 25, respectively (see fig 7).
• a corresponding number of secondary bores 26 are recessed in a portion of the block delimited between the flute 21 and a front end surface 22' on the block.
• a number of separated, bar-like pistons 27 are arranged in said bores 26, the cross-section shape of which pistons - like the cross-sectional shape of the bores - advantageously, though not necessarily, being circular.
• the various pistons 27 are permanently united to a cross piece 28 connected to the slide 4.
• the pistons 27 accompany the slide 4 in the to-and-fro movements thereof.
• a narrow, projecting tenon 29 is arranged on the free end of the individual piston 27, a narrow, projecting tenon 29 is arranged.
• the tenon 29 has, like the piston, a rotary-symmetric, suitably cylindric shape, the same being centrally placed on the end surface of the piston and extending perpendicularly towards this surface.
• the length of the tenon 29 may vary within a limited range, the same should not be larger than 1,5 or 2 times the diameter of the piston, at the most.
• the individual piston bore 23 is provided with a comparatively wide inlet section 30, the 5 diameter of which mainly corresponds to the outer diameter of the individual piston.
• the wide section 30 transforms to a thinner, cylinder-shaped outlet section 32.
• This thin or narrow outlet section is considerably longer than the wider inlet section 30.
• the outlet section 32 may take up 50-80, preferably 70-75 % of the total length of the bore.
• One or more means 33 are built-in in the block 3 for internal heating of the block. These means may consist of elec- trie heating bars or channels for a heat-carrying medium, which may flow through the channels. By using these means, it is possible to heat the raw material passing through the bores to a temperature at which additives such as thermoplast (e.g. from torn packings) melt and bind fibres and other solid component parts in the raw material.
• additives such as thermoplast (e.g. from torn packings) melt and bind fibres and other solid component parts in the raw material.
• a cutting device 34 is arranged in connection with the end surface 22 of the block 3 and the bores 23 mouthing therein.
• the cutting device 34 consists of a rotatable shaft to which a radial wing 35 is applied.
• pellet bodies having the desired length may be cut away from the material strings which are fed out from the bores.
• the individual bores may be of a length within the range of 90-100 mm, the inlet section 30 having a length of 16-20 mm and a diameter of approx. 10 mm.
• the thinner outlet section is of a diameter of approximately 7 mm.
• the tenon 29 on the end surface of the individual piston may be of a diameter of approx. 3 mm and a length of 3-4 mm.
• the cylinder stroke of the slide 4 - and thereby the pistons 27 - may at the same time amount to approximately 40 mm.
• the number o.f pistons together with the appurtenant bores amount to fifteen. Although this number may vary, it should be within the range of 10-20 in order to guarantee a comparatively low power requirement of the motor 10. 6 Function and Advantages of the Machine According to the Invention
• the motor 10 of the machine works continuously at the same time as raw material in the form of sawdust together with possible additives are supplied to the pocket 13, either batchwise or continuously.
• the conveying screw 14 which is driven by means of a separate driving source 36
• the raw material is fed in an even flow down into the funnel 16 and the depth 17.
• the ro ' tatable feeder wing 20 guarantees that the material arriving into the depth 17 is brought down to the bottom space of the flute 21 and is forced in to the open inlet sections 30 of the bores 23 when the pistons are in the returning phase.
• the pistons 27 are movable between first and second end positions.
• first end position which is shown in fig 4
• the free end of the piston is withdrawn so that the bottom space of the flute is laid bare. This means that the raw material forced down by the wing 20 fills out the bottom space.
• the individual piston is brought to the opposite, second end position thereof, according to fig 5, when the drive shaft 8 is brought to rotate half a revolution.
• the raw material in the bottom space of the flute is conducted into the appurtenant bore in which there already is a compressed material string designated 37.
• Another advantage of the machine according to the invention - besides the above-mentioned freedom of dust - is that the machine is small and structurally simple. For this reason, the machine may be manufactured and sold at a low charge, why it may be purchased and used by small-scale buyers, e.g. individual farmers and foresters, small co-operatives, small or medium-sized sawmills or other physical or juridical persons having limited geographic areas for the delivery of the requisite raw material at their disposal.
• small-scale buyers e.g. individual farmers and foresters, small co-operatives, small or medium-sized sawmills or other physical or juridical persons having limited geographic areas for the delivery of the requisite raw material at their disposal.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shearing Machines (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20410936

Family Applications (1)

Country Status (5)

Cited By (10)

Citations (6)

• 1998
  • 1998-04-14 SE SE9801275A patent/SE511869C2/sv not_active IP Right Cessation
• 1999
  • 1999-04-12 AU AU37385/99A patent/AU3738599A/en not_active Abandoned
  • 1999-04-12 WO PCT/SE1999/000584 patent/WO1999052706A1/en active Application Filing
• 2000
  • 2000-10-09 NO NO20005069A patent/NO20005069L/no not_active Application Discontinuation
  • 2000-10-13 FI FI20002266A patent/FI20002266A/sv unknown

Patent Citations (6)

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