SE503362C2 - drum refiner - Google Patents

Abstract

The invention relates to an apparatus for the crushing or grinding of fibrous material, in particular fibrous material wet or mixed with water, preferably chips, in paticular to drum refiners, with an enginedriven rotor having at least two crushing or grinding elements whose surfaces, conveniently rotation surfaces, in particular frustroconical surfaces, are inclined to the rotor axis or extend approximately normally thereto, and have diameters increasing in the direction away from the at least one material feed and a preferably horizontal rotary shaft as well as a housing receiving the rotor having (a) corresponding inner wall(s) and opposing crushing or grinding surfaces disposed thereon, the at least one material feed directed approximately radially to the rotor axis or approximately tangentially to the rotor jacket or housing shell being positioned approximately in the center of said housing and the crushing or grinding surfaces extend from the material feed way on both sides of the jacket of the rotor and correspondingly on the inner housing wall on the inclined or approximately normally extending surface, conveniently rotation surface, in particular frustroconical surface with diameters increasing away from the material feed and the latter surfaces enclose an angle open to the front faces of the rotor on both sides with the axis of the rotor. The invention is mainly characterized in that crushing or grinding surfaces extending approximately parallel to the rotor and corresponding opposing crushing or grinding surfaces arranged on the housing are provided on the jacket of the drumshaped rotor between the material feed as well as that the crushing or grinding surfaces forming the grinding gap extending parallel to the axis and the grinding gap inclined to the axis and the opposing crushing or grinding surfaces are disposed symmetrically in relation to the median plane(s) of the at least one, advantageously two or more material feed(s) conveniently evenly distributed over the circumference of the rotor, in particular approximately radially or approximately tangentially, and that the crushing or grinding surfaces parallel to the axis are followed immediately, in particular merging constantly, by the in particular frustroconical crushing or grinding surfaces inclined towards the axis of the rotor at an angle of approximately 5 to 45 degrees, in particular 15 degrees, said inclined crushing or grinding surfaces optionally being followed immediately, in particular constantly, by merging crushing or grinding surfaces with an angle of inclination larger than the angle of the aoresaid inclined crushing or grinding surfaces, in particular of nearly or approximately 90 degrees, to the rotor axis.

Description

15 20 25 30 35 503 362 2 of high mechanical energy arises, when preferably wet or moist or water-mixed materials are to be crushed or ground, considerable amounts of steam in the grinding gap. For good energy utilization or recovery and as unobstructed supply of the chips or the like as possible, good steam removal is desired together with the produced and recovered fiber mass, which is, however, difficult with such large amounts of steam. Particularly aggravating is the perpendicular arrangement of the grinding gap at the conventional board refiners, since it thereby gives a partial separation of the fibrous material and a strong backflow of the arising steam.

The invention thereby achieves in particular the following objects: reduction of the material load, reduction of the bearing loads, increase of the material throughput and increase of the rotor and shaft speeds, respectively, and an improvement with regard to the steam problem and the steam removal, respectively.

These objects are achieved according to the invention in a drum refiner of the type mentioned in the introduction in that the rotor bearings are arranged in the end sides of the housing and that between the at least one material supply and the crushing grinding surfaces with increasing diameters there are crushing or grinding surfaces running parallel to the rotor shaft. on the jacket of the drum-shaped rotor and corresponding counter-crushing and counter-grinding surfaces arranged on the housing, and that the crushing-parallel and the grinding surfaces, respectively, which are inclined in relation to the shaft, the crushing and grinding surfaces and the crushing and counter-grinding surfaces, respectively. built symmetrically relative to the center plane (s) of the at least one approximately radial or approximately tangential material entrance and the axis-parallel crushing and grinding surfaces, respectively, merge into the crushing or grinding surfaces, which are inclined relative to the axis.

The inventive design of the grinding surfaces ensures a particularly effective defibration during simultaneous feeding of the emerging steam and reduction of the material load, reduction of the bearing loads, increase of the material throughput and increase of the rotor speed, whereby the now possible crushing of the material in the shaft-parallel grinding contents and the special transition from these grinding gaps to the grinding gap inclined relative to the shaft especially improves the crushing work.

In the same direction, it also appears that the anti-crushing surfaces are arranged on a respective two independently displaceable stator ring (s). Refiners according to the invention are particularly suitable for the production of TMP (Thermomechanical Pulp) and CTMP (Chemical Thermomechanical Pulp). According to the invention, the radially applied chip or the like, after it has preferably first been crushed in the horizontal grinding gap, is distributed symmetrically in both directions, whereupon in adjacent inclined, preferably adjustably inclined, preferably conical and possibly even perpendicular to the rotor shaft There is a particularly effective defibration of the wood or the like and in addition the steam removal is improved.

The dosage can be influenced or regulated in that the grinding gaps relative to the axis and perpendicularly, respectively, are adjustable, whereby, for example, the crushing and grinding surfaces are slidably arranged, on a preferably at least two stator approximately horizontally slidably arranged in the housing. - rings). The setting of the grinding gap is important for the regulation of the pulp properties.

A favorable adjustment of the grinding gap can also be achieved in that, especially in the presence of only one displaceable stator ring, the rotor is displaceable on both sides in its bearings, preferably floating bearing. To form such a floating bearing, the rotor can preferably be axially displaceably mounted in a hydrostatic plain bearing, the inner space of the rotor shaft preferably enclosing in the bearing housing, preferably a sliding ring seal, preferably accommodating between this plain bearing and the rotor housing of the housing. The material introduction can take place particularly advantageously, when approximately in the transverse axial plane of the device 10 15 20 25 30 35 503 362 4 and in its housing between the axis-parallel crushing and grinding surfaces, respectively, an annular material supply gap is arranged, which is in communication with a the rotor externally enclosing annular space inside the housing, into which, preferably approximately tangential or approximately radial material inlets open.

According to the further embodiment of the invention, in the area of the two housing end walls close to the rotor or shaft surfaces arranged at an angle parallel to the axis parallel to the axis and possibly relative to the axis approximately perpendicular to the crushing and grinding surfaces, there are arranged cavities, in which it is preferably the conical and perpendicular crushing and grinding gap, respectively, opens. The grinding material thus reaches into the thus formed inner space of the refiner's house and can therefore be carried out together with the arising steam. Steam removal is also facilitated and steam removal devices are made possible. With regard to the origin of steam, the above-mentioned cavities in relation to the two bearings are suitably closed by means of the special sealing elements inserted between the rotor and bearings in the bearing housing on the rotor side by means of inserted special sealing elements. Preferably, these cavities at the bottom have outlet openings for the crushed material.

In practice, a particularly favorable solution is given, when the drum-shaped, on its jacket with approximately crushing and grinding surfaces running approximately parallel to its axis and adjoining crushing, respectively grinding surfaces with, calculated in the direction from the material inlet, increasing diameters and optionally relative to the rotor shaft approximately perpendicularly crushing and grinding surfaces provided with the rotor by means of the rotating shaft fixedly connected thereto is mounted in plain bearings and thus a special starting motor, preferably a direct current motor, is provided for the starting process, and that the main motor is calculated for an operating speed of about 3000 to 3600 rpm at full load. This starter motor may be mounted on a free end of the stator shaft; it requires a considerably lower power than that of the main engine required for the operation of the crushing device, preferably the refiner; the starting current peak is thereby reduced.

Instead of adjoining the shaft-parallel grinding gaps having the shape of truncated cones, the grinding gaps may also have those in the form of other rotating surfaces, for example rotating paraboloids, rotational hyperboloids and the like, however, the diameter of these surfaces, calculated in the direction from the connection point the shaft-parallel grinding surfaces towards the end faces of the rotor, must increase, preferably continuously, to ensure the desired effect with respect to the material flow.

As such, a refiner is already known, in which a conical pin on the circumference is provided with different lengths of crushing rods and which is arranged in the conical inner space of a housing, the inner wall of which carries corresponding counter-rods, so that a 1-2 mm is formed. large grinding gap.

The material is fed on a machine side in the area of the pin shaft. The effect of this refiner is unsatisfactory, since the material is supplied only from one side and immediately at the shaft directly in the conical grinding gap. Satisfactory defibration and sufficient digestion effect can thus not be achieved. The same applies to the known grain mills.

In addition, a microfine grinding device means prior art, in which by means of a transport screw goods are fed centrally from above to a grinding hammer running parallel to the axis of a sieve impeller, which form a gap arranged parallel to this axis with the housing receiving this impeller, which in its inner wall does not shows some recesses. The goods ground in this parallel gap are carried from the outside in by an air stream from the grinding zone and thereby pass the above-mentioned sight impeller. The bulk material separated therein then reaches back to the grinding zone. Two fan wheels arranged on both sides of the mill shaft provide the required air flow. Apart from the fact that in this known embodiment conical grinding slits or the like do not connect to the shaft-parallel grinding gap, they are not suitable for processing chips or other wet fibrous material, for which purpose particularly expensive constructions are needed.

With reference to the drawings, exemplary embodiments of the invention are described, more particularly a drum refiner for producing wood pulp from wood chips. Then: Fig. 1 shows an axial section A-B according to Fig. 2; Fig. 2 is an end view; Fig. 3 is a section along the plane C-D in Fig. 1 in a detail enlarged in relation to Fig. 1; and Fig. 4 shows a corresponding section along the plane E-F again in magnification. Fig. 5 gives yet another enlarged detail of a variant in a similar section as Fig. 4. Figs. 6-8 show a variant with changed grinding gap and floating rotor bearing in axial section and in front and side view.

According to Figs. 1-5, a cylindrical rotor 2 is stored in a preferably horizontally divided refiner housing 1 on both sides of the bearings 3, 4 and 5, whereby depending on the diameter, capacity and speed roller or plain bearings, any pivot segment plain bearings can be inserted. Grinding plates 6 and 7 are arranged on this rotor 2, the ones arranged along a cylindrical jacket part serving for crushing (grinding plates 6) and those enclosing an angle to the rotor shaft serve for defibration (grinding plates 7). Due to the shape of the grinding plates 7, an inclination of the grinding zone in relation to the horizontal line of between 5 and 45 °, preferably 15 °, is achieved.

On two stator rings 8, which are horizontally displaceable for adjusting the grinding gap, grinding plates 9 and 9 ', respectively, are arranged, which co-operate with the grinding plates 7.

Figs. 3 and 4 show on a somewhat enlarged scale a detailed cross-section through the grinding plate area, and more particularly in Fig. 3 in the axis parallel, in Fig. 4 in the truncated conical area.

According to Fig. 4, the counter-strips 17 in the outer grinding plates 9 are reinforced with transverse projections and transverse strips 18, respectively. These projections and strips 18 are arranged to hold back the fibrous material, i.e. increase its residence time in the grinding zone. The inner grinding plate 7 in the truncated conical area can be built up of segment 7 '(Fig. 4). Such an embodiment with size ratios specially adapted to the practice is shown in Fig. 5, however only with partially indicated transverse projections 18. Anchor extensions 19 are arranged in corresponding rotor grooves 20 with hammer-head-like cross-section.

The chip is supplied, more precisely by means of a screw, in this example radially through one to four material inlets 10 with openings in the circumference. The chips are crushed in a horizontal grinding gap 11 and distributed in both directions. The defibration of wood takes place in the grinding gap 12 which is inclined in relation to the horizontal line. The grinding material then reaches into the inner space 13 of the refiner housing 1 and is carried out at 14 together with the arising steam.

The bearings are sealed by means of sealing units 15 against the steam in the refiner housing.

On the free shaft end 16, a motor, preferably a direct current motor, with significantly lower power than the main motor can be installed, so that the starting current peak is reduced.

Due to this modified design in relation to existing refiners, the refiner can be operated at speeds up to 3600 revolutions per minute.

The invention can also be advantageously applied to refiners with a vertical rotor shaft. In addition, grinding of fibrous materials other than wood can thus be carried out, whereby in the case of pre-ground material water or other liquids must be added.

According to the invention, a considerable reduction of the material stress is achieved in comparison with known refiners and the like, whereby the bearing load is reduced and the service life of the bearings is extended. An increase in the material throughput can therefore be achieved.

The design according to Figs. 6-8 differs from the one described above mainly by the type of material supply, by the special rotor bearing and the modified stator setting. Corresponding parts are provided with the same reference numerals as in Figs. 1-5. The material supply here takes place here at 110 'in two places approximately tangentially in relation to the rotor 102 in the annular space 110 ", from where the material then reaches the grinding plates or the like. The shaft ends 116' of the rotor 102 and thus the rotor For this purpose, hydrostatic sliding bearings 203 and 204 are arranged in the bearing seats 201 and 202. The bearings are again sealed by means of cover units 115 'to the steam in the refiner housing 101. By means of the double arrow 205, the rotor bearing made possible by the rotor bearing described above. Although in this case the adjustability of only one stator may suffice, in the present case also adjustment has been made for both stators 8 and accordingly the grinding plates or the like 206, 207 attached thereto; these grinding plates or the like have adjacent the frustoconical portions 208, 209 portions 210, 211 forming a larger angle, more precisely by almost 90 ° to the rotor shaft, than the parts 208, 209. The parts 210, 211 cooperate with further grinding plates 212, 213, which also run steeply towards the motor shaft such as the parts 210, 211 and are supported by special rings 214, 215, which are connected to the rotor 102.

The adjustment of the stators 8 and thus the grinding plates or the like 206, 207, 210, 211, but also the cylindrically shaped grinding plates takes place in a similar manner as in Figs. 218, which in turn is displaced uniformly by the adjusting means 7-9. With regard to the floating stored rotor, the setting of a single stator would also be conceivable here.

The other stator could then be stored immovably in the bearing housing. The mobility of the grinding gap setting takes over the free axial displacement (floating bearing) of the rotor.

Claims (17)

10 15 20 25 30 35 503 362 PATENT REQUIREMENTS Drum refiner for crushing, for example grinding of particularly wet and water-mixed, fibrous materials, with a rotor stored on both sides with at least two crushing and grinding elements having, relative to the rotor shaft inclined rotational surfaces with away from, at least one, in the center material supply increasing diameter and with a counter-inclined inclination relative to the rotor shaft and approximately horizontal axis of rotation and a rotor receiving housing with corresponding inner wall (s) and counter-crushing or grinding surface (s) arranged thereon, the at least one , approximately radially relative to the rotor axis or approximately tangentially relative to the rotor or housing casing directed, the material supply is arranged approximately in the middle of this housing and on the rotor casing and correspondingly on the housing inner wall the crushing and grinding surfaces extend outwardly on both sides of the material supply on the inclined rotating surface. with from matter the latter supply increases in diameter, and the latter form an angle with the rotor shaft open at both sides towards the end sides of the rotor, characterized in that the rotor bearings are arranged in the end sides of the housing and that between the at least one material supply and the crushing or sealing surfaces (7). ) with increasing diameters there are crushing and grinding surfaces (6) running approximately parallel to the rotor axis on the casing of the drum-shaped rotor (2) and correspondingly crushing and grinding surfaces (9, 9 ') arranged on the housing (1). , and that the crushing, grinding, grinding surfaces and the crushing and grinding surfaces, respectively, forming the axis parallel and the oblique, oblique grinding gap forming relative to the axis, are constructed symmetrically with respect to the center plane (s) of the at least one, approximately radial or approximately tangential material. the input (10) and the shaft-parallel crushing, respectively 10 15 20 25 30 35 503 362 10 grinding the surfaces (6) immediately merge into the relatively axially inclined crushing and grinding surfaces (7), respectively. 2. A drum refiner according to claim 1, characterized in that the inclined crushing or grinding surfaces (7) connect immediately to the shaft-parallel crushing and grinding surfaces (6) at an angle of approximately 15 °. 3. A drum refiner according to any one of claims 1-2, characterized in that the shaft-parallel crushing and grinding surfaces (6) continuously merge into the crushing and grinding surfaces (7), which are inclined relative to the rotor shaft. Drum refiner according to one of Claims 1 to 3, characterized in that to the inclined crushing and grinding surfaces (7), respectively, immediately intersecting crushing and grinding surfaces (206, 207), respectively, are provided with a relatively above-mentioned oblique crushing. -, respectively grinding surfaces increased angle of approximately 90 ° relative to the rotor shaft. Drum refiner according to one of Claims 1 to 4, characterized in that the anti-crushing and anti-grinding surfaces (9, 208, 209), which are inclined relative to the axis, are arranged on at least two in the housing approximately horizontal with the transverse plane of the material supply for - sliding stator rings (8). 6. A drum refiner according to claim 5, characterized in that the anti-crushing and anti-grinding surfaces (9, 208, 209) are arranged on at least two independently displaceable stator rings (8). 7. A drum refiner according to any one of claims 1-6, characterized in that the rotor (2, 102) is slidably mounted on both sides in its bearings (3, 4, 203, 204). Drum refiner according to claim 7, characterized in that the rotor is mounted axially displaceably in a hydrostatic plain bearing (3, 4, 203, 204), a sealing unit (15, 115 ') enclosing the rotor shaft 10. (16, 116 ') between this plain bearing and the interior of the housing receiving the rotor (2, 102). Drum refiner according to one of Claims 1 to 8, characterized in that an annular material supply gap is arranged approximately in the transverse axial central plane of the housing (1, 101) between the shaft-parallel crushing and grinding surfaces (6), which communicates with a ring space (110 ") externally surrounding the rotor (2, 102) in the housing (1, 101), into which the material supply (10) opens. Drum refiner according to one of Claims 1 to 9, characterized in that in the region of the two end walls of the housing near the rotor (2) provided with the shaft parallel and relative to the shaft inclined, for example grinding surfaces (7) , 102) arranged cavity bearings are arranged cavities (13, 113), in which crushing and grinding slots (7, 206, 207) open, these cavities being tightly closed in relation to the two bearings (3-5, 203). , 204) by means of the special sealing units (15, 115 ') inserted between the rotor (2, 102) and the bearings in the rotor housing on the rotor side. A drum refiner according to claim 10, characterized in that the cavities (13, 113) arranged at the bottom in the area of the housing end walls have outlet openings (14, 114) for the crushed material. Drum refiner according to one of Claims 1 to 11, characterized in that the drum-like, on its jacket having crushing and grinding surfaces (6) running approximately parallel to its axis and crushing and grinding surfaces adjoining them on both sides, respectively. (7) with rotating diameter (2, 102) provided with increasing diameter away from the material supply (10) by means of the rotary shaft (16, 116 ') fixedly connected thereto is mounted in plain bearings (3-5, 203, 204) and therefore a special starter motor is provided for the start-up operation, and that the main motor is calculated for an operating speed of approximately 3000 to 3600 revolutions per minute at full load. 10 15 20 503 362 12 Drum refiner according to one of Claims 1 to 12, characterized in that two different stator rings (8) are arranged on both sides of and at equal distances from the central plane of the material supply (10). Drum refiner according to one of Claims 1 to 13, characterized in that shaft-parallel anti-crushing or anti-grinding surfaces are also arranged on at least two displaceable stator rings (8). Drum refiner according to one of Claims 1 to 14, characterized in that the crushing or grinding elements on the rotor (2, 202) on its circumference have axially extending strips. A drum refiner according to any one of claims 1-15, characterized in that the anti-crushing or anti-grinding surfaces (9) have axially extending strips on the inner surfaces of the housing. Drum refiner according to Claim 16, characterized in that the strips on the anti-crushing or anti-grinding surfaces (9) are reinforced with transverse strips (18) running in the circumferential direction.