FI56563C - ANORDINATION FOR FRAMSTAELLNING AV MASS PAO MECHANICAL VAEG AV TRAEFLIS - Google Patents

Description

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Ma lj 1; utlAggningsskrift bobo3 C (45) Patent granted 11 C2 1930 ·

Patent Meddelat '(51) Kv.ik. * / It * tci. » D 21 B 1/14 SUOM I - FI N LAN D (21) Ptt «nttJh» k * mu »- Patentaraeiming 781278 (22) Htk * ml * pilvl - An * ttknlnj * d * g 2 5. 0U. 7 8 * * (23) Atkupilvt - Glltighetsdag 25.0U.78 (41) Has become public! - Bllvlt offentllg 26.10.79

National Board of Patents and Registration .... U1 ..,,. . ., .., _ ^ \, (44) Date of delivery and hearing. -

Patent-och registerstyrelsen 'Ansölun utligd och utUkrlften publlcerad 31.10.79 ^ (32) (33) (31) Requested privilege — Begird pplorltet (71) Enso-Gutzeit Osakeyhtiö, Kanavaranta 1, 00l60 Helsinki l6,

Finland-Finland (FI) (72) Jorma Surakka, Savonlinna, Finland-Finland (FI) (5U) Device for the mechanical production of pulp from wood chips -

The present invention relates to an apparatus for mechanically producing pulp from wood chips, which is fed by a feeding device against discs with a grinding surface, which provide a reciprocating grinding movement in the wood chips, whereby the fibers are detached from the wood.

In the paper industry, pulp is mechanically produced in large quantities, especially as a raw material for newsprint. There are mainly two methods, the grinding method and the Thermomechanical Pulping (TMP) method, in which the wood pile is pressed against an abrasive ceramic surface, whereby the pulsating and abrasive effect of the surface detaches the fibers from the wood. In the TMP method, the wood raw material is usually 200-300 kPa) is inserted between two opposing flat discs.The discs rotate relative to each other either in opposite directions or so that one disc rotates and the other is fixed.The surface of the discs is toothed and rough and the chips break into fibers as they pass between the discs.

Grinding produces a lower strength mass than TMP, but requires less energy for the process, about 4 MJ / kg, discipline TMP uses about 6 MJ / kg.

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Due to the high annual production of pulp, millions of tons / year, strong efforts have been made to develop pulping methods that would make good pulp with low energy consumption.

Among others, the Pulp and Paper Research Institute of Canada (PPRIC) has found that wood can be mechanically made into a paper that is very well suited for papermaking by grinding the surface of the wood back and forth (explained in PPRIC's Trend v. 66). The surface shape of the abrasive surface does not have very specific requirements, as the mechanism is based on the abrasive surface detaching the fibers and further causing the fibers to adhere to the surface of the wood at one end. As the direction of travel of the abrasive surface changes, the detached fibers adhere at their ends to the fibers adhering to the surface of the wood, pulling them off, and these detached fibers provide new fibers detached at one end. Therefore, the in the process, the fibers between the abrasive surface and the surface of the wood, rather than the surface of the abrasive body, act as an intermediate in defibering the wood.

The study further found that if the abrasive surface moves in the same direction all the time, said process does not occur because the fibers adhering to the surface of the wood comb in the direction of travel and the fibers detached by the abrasive surface do not become entangled in them. The fibers are thus detached only by the abrasive action of the abrasive surface, as in the commonly used abrasive process. The quality of the pulp is then much worse and the energy consumption higher.

Due to the great economic importance of high-quality pulp produced with low energy consumption, the Institute tried to develop a device that could produce said pulp on an industrial scale. Finnish patent 427 & 1 describes some of the equipment operating on the principle of subsidiarity, but does not include any that can achieve production capacity of economic importance. Indeed, the PPRIC publication Trend states that the hardware implementation of the process was not achieved despite the attempts.

The above invention is based on the above method and is intended to provide a simple device for carrying out the method.

The device according to the invention is characterized by what is stated in the claims.

The device according to the invention will now be described in detail with reference to the drawings, in which Figure 1 shows a vertical section of a preferred embodiment of the device according to the invention, Figure 2 shows the device of Figure 1 in plan direction II-II, Figure 3 shows a top view in line III-III of Figure 1, and Figure 4 shows a cross-section taken along the line IV-IV in Figure 1.

According to Figure 1, the device preferably comprises a vertical body tube 1 fixed to a concrete base, the upper end of which has a fixed disc 2 with a horizontal grinding surface, 6 holes 3 as shown in Figure 2, extending close to the outer circumference of the disc 2 and centered on the circumference of the disc 2 on the circumference of a concentric circle. Rotating discs 4 are provided in the holes 3 with a small clearance, which are provided with an abrasive layer 5 extending to the level of the upper surface of the disc 2, which may be a rough metal or ceramic material.

As shown in Figures 1 and 4, the shafts 6 of the rotating discs 4 are alternately connected in the circumferential direction of the disc 2 to chassis-supported upright motors 7 and bearing housings 8. Each shaft 6 connected to the motor 7 has a horizontal gear 9 in clockwise contact with the shaft 6 of the next disc. with a gear 10 of equal diameter, so that the rotational movement transmitted by each motor 7 to its own rotating disk 4 is transferred with equal circumferential speed but in the opposite direction to the next disk 4, which rests on its shaft 6 in the bearing housing 8.

According to Figures 1 and 3, the grinding zone of wood chips is formed by an annular space 13 between two concentric cylinders 11 and 12 open at their upper and lower ends. , by means of which a bearing 17 allows the cylinder 11 to rotate with respect to the body tube 1.

The cylinder 11 is fixed on its outer surface to the inner surface of the cylinder 12 by radial horizontal flat irons 18, the flaps of which are vertical. The cylinder 12, in turn, is fixed from its outer surface to a circumference 20 with external toothing of the horizontal radial mounting arm 19, which is driven by a motor 22 via a gear 21.

Attached to the upper end of the protrusion 15 of the body tube 1 are radially and obliquely upward bearing housings 23 on which, as shown in Fig. 2, 7 conical rollers 24 are mounted on their respective shafts 25, supported at their outer end by a bearing 26 on a fixed wall (shown schematically in 2 off). The shafts 25 are set at such an inclination that the conical rollers 24 press the wood chips in the ring space along their entire length along their length. According to Figures 1 and 2 4 56563, the rollers 24 are provided with bearings 23, 26 set at a certain inclination, whereby the pressure exerted by the rollers 24 on the wood chips cannot be adjusted. It is clear, however, that the bearings 23 can be articulated to the projection 15 ', whereby the inclination of the shafts 25 can be changed by a suitable mechanism, so that the compressive force of the conical rollers 25 can be adjusted to suit different grinding conditions.

According to Figures 1 and 2, the device is provided with a wood chip conveyor device comprising a horizontal tube 27, inside which a rotating conveyor screw 28 introduces the wood chips into a vertical chute 29, from which it is divided into a ring space 13.

The device according to the invention operates in the following way:

The chips to be defibered are introduced by a conveyor screw 28 into the upper part of the vertical chute 29, from where it is allowed to fall freely against the disc 4 at the bottom of the ring space 13. According to Figure 4, this disc on the extreme left is rotated clockwise by a motor 7 about an axis 6. The wood chips grinding discs 4 are provided with a grinding layer 5, which can be a ceramic material corresponding to normal abrasive stone or also a roughened metal. The sanding layer 5 partially detaches the fibers from the chips, the size of which is thus reduced. Part of the surface of the chips leaves fibers attached at one end, which, due to the rotational movement of the disc 4, comb in the direction of rotation of the disc. When the disc 4 rotates immediately from the surface of the disc 4, the detached fibers are outside the ring space 13, since the outer cylinder 12 forming the outer wall of the ring space 13 passes through the centers of the discs 4 (Figures 1 and 3). The fibers detached from these surfaces of the discs 4 outside the annular space 13 are removed, for example, by using water jets.

The reduced size chips are moved forward clockwise in the ring space 13 by means of rotating cylinders 11 and 12 connected by radial flat irons 18 relatively close to the grinding layer 5 in the ring space 13, which take the "chips close to the grinding layer 5 with them. The flat irons 18 leave the trays. once to the next disc 4. When the direction of rotation of this disc is opposite to the direction of rotation of the previous disc according to Fig. 4 because the gear 10 on the shaft 6 of this disc is rotated by the gear 9 on the shaft 6 of the motor 7 ', a counter-grinding movement according to the basic idea of the invention is obtained. found to be beneficial in terms of fiber energy consumption.

Claims (9)

Apparatus for mechanically producing pulp from wood chips, which is introduced against discs (4) by a feed device comprising a ring space (13), which apply abrasive forces to the wood chips, causing the chips to grind into fibers, characterized in that the wood chips are pressed against the feed space in the ring space (13) (5) provided with flat discs (4) rotating about their vertical axes (6), which, when rotated in pairs in opposite directions, provide grinding forces acting back and forth on the chips as the chips move from one disc (4) to another in the ring space (13). 6 56563 Device according to Claim 1, characterized in that the grinding layer (5) of the discs (4) is made of ceramic material or roughened metal. Device according to Claim 1 or 2, characterized in that the feed device is formed by concentric cylinders (11, 12) leaving an annular space (13), which are connected from the inside by radial flat irons (18) which transfer chips and from which the cylinder (12) is fastened from the outside. on the arms (19) to the gear ring (20) rotating the feeder. Device according to one of Claims 1 to 3, characterized in that the chips in the ring space (13) are pressed against the discs (4) by conical rollers (24). Device according to one of Claims 1 to 4, characterized in that the cylinder (12) extends halfway over the surface area of the discs (4). 5 $ 6563 The clockwise rotation of the next disk 4 is set in the direction of rotation of the motor 7 rotating it again opposite to the direction of rotation of the previous disk, and when the gear 9 on the shaft 6 of this disk 4 is in contact with the next gear 6 on the freely rotating shaft 6 in its bearing 8, disc 4 again in the opposite direction of rotation. Thus, the chip rotating in the ring space 13 is subjected to a parallel grinding movement at every other disc 4. In addition to the fact that the energy consumption of the fiberization in the device according to the invention is lower than in the normal TMP process, other advantages are also achieved. When the ring space 13 is full of chips to be ground at any time, the steam generated on the surface 5 in the grinding layer enters the chips immediately above, which are softened by the steam. The moisture content of the chips also becomes optimal for the grinding process. Since the chipping of the chips takes place immediately in the grinding layer, no pre-steaming of the chips is required, which would require a pressurized construction. The invention is not limited to the embodiment described above, but can be modified within the scope of the appended claims. Thus, the ring space 13 may extend over the entire surface area of the discs 4 and may also be provided with a partition, whereby the ring space is divided into two different parts, where the wood chips are pressed against the discs 4 in a row. Device according to one of Claims 1 to 4, characterized in that the cylinder (12) extends over the entire surface of the discs (4). Device according to Claim 6, characterized in that there is a concentric partition wall between the cylinders (11, 12), the chips in different parts of the ring space (13) being pressed against the discs (4) by separate conical rollers (24) on the same shafts (25). . Device according to one of Claims 1 to 6, characterized in that the discs (4) are arranged in holes (3) arranged in the fixed disc (2). Device according to Claim 1, characterized in that in the direction of rotation of the cylinders (11, 12) every second disc (4) is rotated by a motor (17) whose gear (9) is in contact with the axis (6) of the next disc (4). ) with the gear (10). 7 S6563