EP3233402A1

EP3233402A1 - Process for disintegrating lignocellulosic material in a drum chipper

Info

Publication number: EP3233402A1
Application number: EP15870456.9A
Authority: EP
Inventors: Åke SVENSSON; Per-Gustav JONASSON; Marie EDIN
Original assignee: Multi Channel Sweden (mcs Ab) AB
Current assignee: Multi Channel Sweden (mcs Ab) AB
Priority date: 2014-12-17
Filing date: 2015-12-09
Publication date: 2017-10-25
Anticipated expiration: 2035-12-09
Also published as: EP3233402A4; WO2016099380A1; SE1400599A1; EP3233402C0; EP3233402B1; SE542730C2

Abstract

The present invention relates to a process for disintegrating lignocellulosic material (1) in a drum chipper. The process includes that the lignocellulosic material (1) is introduced to the drum chipper via an input device (2) and that the disintegrated lignocellulosic material is analysed (9) regarding its configuration. The disintegration takes place in a drum chipper comprising a stand carrying a horizontal, rotatable rotor (26), whose periphery has a plurality of knifes (30) and with each knife (30) cooperating radially adjustable wear plates (25) located at some distance from the knife edge, and a space for temporarily collecting the disintegrated lignocellulosic material between each pair of knives (30) and anvil steels. The process is characterized in that at least one process variable is changed during operation in the form of, that a certain cutting angle (ε) is set by regulation of the feeding device (2) position versus the rotor (26) and/or a specific T dimension is adjusted by changing the wear plate's (25) radial distance from the rotor (26) centre and/or that a certain cutting speed, i.e. the knife speed through the lignocellulosic material (1) is adjusted by changing the speed of the rotor (26).

Description

PROCESS FOR DISINTEGRATING LIGNOCELLULOSIC MATERIAL

IN A DRUM CHIPPER

Technical field:

The present invention relates to a process for changing, during operation, at least one process variable when disintegrating elongated lignocellulosic material in apparatus in the form of a drum chipper.

There are numerous uses for comminuted lignocellulosic material that in most cases is referred to as chips. One important use is the production of cellulose pulp. This can be prepared in a number of different ways, and more specifically by chemical, semi-chemical, and mechanical routes. Examples of chemical preparation methods are the sulphate method, the sulphite method, and the soda method. By semi- chemical pulp is meant that the lignocellulosic material (the wood chips) is digested to some extent by means of a cooking liquor, whereupon the defibration takes place mechanically. Mechanical pulp is usually divided into groundwood pulp, thermomechanical pulp (TMP) and

chemithermomechanical pulp (CTMP). Another use of disintegrated lignocellulose materials is in the production of various types of sheet material. A third use is as a fuel for the power (electricity) and heat industry, and a fourth use is in the biomass industry. Lately torrefaction of wood chips has once again been brought up to date, and then mainly in the literature.

A dominant lignocellulose material is different types of trees from which wood is extracted. A distinction is usually made between long- fibred and short-fibred wood. Long-fibred wood is, for example, extracted from spruce and pine, while short-fibered wood is, for example, extracted from birch, beech, aspen, oak and eucalyptus. The tops and branches of the tree, and sometimes also the tree stump are also used. The latter materials are primarily used in power and heating plants and in the biomass industry. There are several other types of lignocellulosic materials such as bamboo and bagasse. The latter is the material that is obtained after the bulk of the sugar is removed from sugar canes. State of the art:

The appearance or configuration of the disintegrated lignocellulosic material, e.g. chips, is of varying importance depending on field of application. The term configuration refers to the length, width and thickness of the chips. In the production of cellulose pulp, for example, the configuration of the chips is of very great importance. It is not easy to consistently produce high quality/optimal chips from the wood material, which is realized by the fact that the incoming wood material can vary in several ways. Partly, for example, a pine tree portion may be followed by a spruce portion and partly one and the same wood species may vary in quality depending on where the trees have been grown, site quality, i.e., woodland vigour, may vary from one place to another, which affects how lush tree becomes, i.e., the thickness of the annual rings. The thickness of the annual rings also varies with habitat in southern and northern direction, respectively.

In the literature there are proposals on how to overcome quality differences in incoming raw materials, e.g. wood material.

The cutting angle/chipping angle, i.e. the angle at which the knife hits the lignocellulosic material, e.g. the tree log, effects the disintegration of the resulting chips configuration. Swedish patent application 1 100109-6 describes how the cutting angle/chipping angle (e) in a drum chipper may be varied. It discloses a drum chipper with connecting infeed conveyor comprising a stand that supports a cylindrical and rotatably disposed rotor, onto the periphery of which a number of knives are mounted. The knives pass an anvil steel device, which is positioned so that a chipping angle (e) arises between the knife edges' plane of rotation and the anvil steel's upper plane with the associated infeed conveyor's transportation plane. The cutting angle (e) affects the chip length by the mathematical relationship T/sin e. The size of the cutting angle furthermore affects the chip thickness and compression damages. Compression damages to the chips are sometimes seen as something negative, but some compression damage to the chips is sought for at the production of, for example, thermomechanical pulp (TMP).

Swedish patent application 1000181 -6 teaches how the chip length may be varied in a chipper. A method is described for changing the chip length in a chipper by displacing an adjustable wear plate while the width of the chips opening is changed in a chipper machine for roundwood, which may be of the type rotary chipper, preferably for the production of wood chips for paper pulp manufacture, so-called cellulose chips or chips for combustion, fuel chips and is provided with two or more wear plates to hold the wood end face at the right distance in relation to the knife's edge during the chipping process, which by those skilled in the art is known as the T dimension, which predetermines the chip length in combination with the cutting angle e, where increased distance provides for longer chips and vice versa, and that it is also essential that the chip opening, the width of which is called the S dimension, should be slightly larger than the chip length and has a relation to the T dimension.

The method is characterized in that an altered T dimension simultaneously provides an altered S dimension, by that the wear plate rests on a fixed support surface on the rotor and adjusting device mounted in the rotor and is held by resilient bolt connection with bolt and spring, and that its movement towards the knife edge is limited by an inclined plane where the angle determines the relationship between the altered T dimension and S dimension and where the pressure and friction of the wood against the wear plate in combination with the relative motion difference between wood and wear plate generates a force that maintains the wear plate's bearing against the inclined plane.

Regarding the drum chipper with horse shoe shaped channels for collecting the freshly comminuted lignocellulosic material, e.g. wood chips, and discharge of the material from the drum chipper, problems often occur at those two instances. A solution to this problem is described in Swedish Patent 527294 (0200600-5). Therein, a disintegrating machine of drum chipper type comprising a stand carrying a horizontal and rotatable drum/rotor, on the periphery of which a plurality of knifes are mounted in knife holders and substantially uniformly distributed over the drum/rotor periphery and circumference, an anvil steel arranged at a substantially constant radial distance from, and interacting with, the drum/rotor in the stand, and where knife holder with knife is designed so that a channel is formed with its top at the knife tip and towards the centre and which then bends towards the periphery with its opening in the rotational direction after the knife tip. The characterizing and distinctive is that the channel from the knife to its radial opening in the drum/rotor periphery has a widening cross section, the distance Z<X<W. Said distance is indicated and disclosed in, for instance, Figure 3 of the patent document.

As seen above, it has already been disclosed how drum chippers can be designed, and also be operated for the purpose of achieving desired configuration of the comminuted lignocellulosic material, e.g. wood chips, as well as avoiding production disruptions.

Description of the Invention

Technical problem

The outputted disintegrated lignocellulose material from the chipper, e.g. wood chips, has been analysed for a long time been, manually or instrumentally. It is becoming increasingly more frequent to switch to analysing the resulting wood chips quality, e.g. its configuration, instrumentally. When it has been realized that the chipper settings, i.e. the process variables, would have to be changed, it has up until now been necessary to stop the drum/rotor. This is disadvantageous for the production of wood chips, or expressed otherwise, for the utilization of the drum chipper capacity. Since stopping the drum chipper is not desirable from a production point of view this impacts on the quality of the produced wood chips. Until now it has had to be accepted to wait to stop the drum chipper, even though the chips quality deteriorates, in order not to deteriorate the production capacity, i.e. the amount of chips produced during, for instance, one day. Solution

These problems are solved by the present invention, which relates to a process for disintegrating elongated lignocellulosic material in an apparatus in the form of a drum chipper with connecting input means for the purpose of achieving a desired (predetermined) quality of the disintegrated lignocellulosic material, comprising feeding the elongated lignocellulosic material to the drum chipper that consists of a stand carrying a horizontal and rotatable drum/rotor, the periphery of which has a plurality of knifes contained in knife holders as well as with every knife interacting radially adjustable wear plates positioned at a certain distance from the knife and its edge, and a space for temporarily collecting the disintegrated lignocellulosic material, said space being positioned between each knife and one or more anvil steels that interact(s) with each respective knife, said anvil steel(s) preferably being attached to the stand, and manually or instrumentally, intermittently or continuously analysing the outputted disintegrated lignocellulosic material primarily regarding its configuration, characterised in that at least one process variable is changed during operation by setting a certain chipping angle (□) by regulation of the input means' position vis-a-vis the rotor causing the fed elongated lignocellulosic material to approach and be brought towards the rotor at a certain angel and/or setting a certain T dimension value

(distance between the knife edge and the wear plate calculated according to a known formula) by changing the wear plate's radial distance from the rotor's centre, preferably after temporary lowering of the rotor's speed and/or setting a certain cutting speed, i.e. knife speed through the lignocellulosic material, by changing the rotor's speed.

The elongated lignocellulosic material can be fed to the rotor via an elongated chute device, the front end of which is rotatably mounted in a stand, and which chute device at a distance from the front end is equipped with lifting and lowering means, which is/are attached to the chute device as well as the stand, and which means work automatically and preferably following instructions through a computer. According to another embodiment of the invention the chute device is replaced by a chain feeder, while otherwise being similar to what is indicated above. Alternatives to chain feeder are roller feeders, vibrating feeders, apron feeders and conveyors.

Following, for instance, the above mentioned chain feeder, the elongated lignocellulosic material, e.g. a wood log, may be brought in the transport direction to pass over and in connection to anvil steel arranged at an inclination corresponding to the inclination of chain feeder. In this case, the anvil steel(s) attached to the drum chipper may be excluded.

In yet another embodiment of the invention, the elongate lignocellulosic material is brought, during the input process, to pass a measuring device which determines the height of the object or, alternatively its diameter. If the height exceeds a predetermined value then said angle (inclination) is set so as to minimize the chipping angle.

If an object with extremely large diameter happens to be input to the drum chipper is possible to tilt the object away from the input means to prevent stops in the drum chipper and/or damage to the same. In a preferred embodiment of the invention, the generated comminuted lignocellulosic material, e.g. wood chips, is collected in a duct beginning (with a first opening) at the knife's edge and which extends towards the rotor's centre and which then deflects towards the periphery of the rotor with its second opening in the rotational direction after the knife, and the breadth and the T dimension of the first opening is set by means of a rod with a concentric cross section or a cross section with stepwise increasing height, said rod being enclosed in a holder for the wear plate, which is spring-loaded connected to the holder, and the rod's outwardly facing side rests against the wear plate's inner side, and said setting is achieved by turning the rod so that the wear plate is forced outwards or inwards depending on the turning direction, which rotational motion is automatic and preferably following instructions through a computer.

As evident from the above the field of application of the comminuted lignocellulosic material determines how the comminution in the drum chipper is performed, i.e. the process variables that are selected. In some fields of application, larger differences in quality of the resulting material is tolerated, e.g. regarding its configuration in terms of width, length and thickness, than in other fields of application. However, attempts are being made to bring about that the lignocellulosic material that is fed to the drum chipper, as well as to other chippers are as similar as possible seen over time. Unfortunately, the reality is such that many performers have to live with that the starting material/raw material varies in higher or lower degree, i.e. that the incoming lignocellulosic material, for example, wood species varies. The difference may consist of softwood vs. hardwood. There are at least two kinds of softwood, e.g. spruce and pine. The variety of hardwood is even greater, and can be counted in tens. For every change of the incoming raw material the chipper, according to known comminution technology, must be stopped, i.e. be taken out of operation in order to enable changing one or more process variables. The production capacity of the chipper decreases with increasing number of stops. Even with consistent access to one and the same kind of lignocellulosic material, e.g. a specific wood species, this does not mean freedom from problems. As mentioned above, the width of the annual rings of the tree may vary depending on the habitat, i.e., the tree can be fast-growing or slow-growing. Depending on season the wood freshness and temperature may vary. As well known the tree dimensions, such as diameter, may vary greatly. Such variations lead to that the process variables in the comminution of the wood, e.g. in the form of logs, must be varied.

According to a preferred embodiment of the invention the comminution of the lignocellulosic material in the drum chipper is controlled by means of a computer program and a computer. Desired setpoints regarding the produced chip configuration in terms of length, width and thickness are input into the computer program. If the analysis of the produced chips shows that the actual values deviate adversely from the setpoints then at least one of the previously specified process variables are changed while the drum/rotor continues to spin and produce chips, until the actual values are consistent with the setpoints. Hence, at the transition between two different wood portions the drum chipper does not have to be stopped; instead the drum chipper is instructed more or less instantaneously by the computer program which process variables are the right ones.

Below are some examples of how to vary one or more process variables to achieve desired quality of the chips.

If the analysis shows that the length of the chips is too short, which means that longer chip length is desired, then the T dimension is increased, which according to the invention takes place automatically and preferably computer-controlled. If it is desired to maintain the chip thickness then the chipping angle is simultaneously slightly decreased.

If the analysis shows that the length of the chips is too long then the T dimension is decreased with simultaneous reduction of the cutting speed.

If it is desirable that the chips should be compression damaged, as in the production of chips for TMP production, then the chipping /cutting angle is increased. It is advantageous to also increase the angle of the knife edge, which must be done when changing knifes.

Although the aim of the process according to invention is to never stop the drum chipper, this is sometimes necessary, for example when the knifes are worn out and when one or more stones or any other very compact (hard) material has found its way into the drum chipper. Advantages

One advantage of the invention is that in comparison with prior art the capacity increases, i.e. the amount of chips produced during for example one day. Every percent of capacity increase is positive. The invention leads to a downtime reduction, with a capacity increase as result.

Another advantage of the invention is that it enables an improvement in chip quality. This is due to that the process according to the invention makes it is possible to almost instantaneously change one or more process variable(s) after the analysis of newly prepared chips shows that the chips deviate from the desired quality. Since according to prior art a drum chipper must be stopped to make a change in one or more process variable(s) this inevitably leads to delaying of a stop although there are indications that the chip quality is deteriorating. During this period chips are produced with lower quality.

Description of the figures

Figure 1 is a system related outline of the process of according to the overall invention. It furthermore shows a suitable apparatus for performing the process according to the invention.

Figures 2a and 2b show means for turning the camshaft (the rod) during operation from different perspectives.

Figure 3 schematically shows how said turning affects the wear plate's radial position, which in turn determines the T dimension set.

Best mode of operation

Preferred embodiments of the process according to the invention are described below with reference to said figures. Furthermore additional and detailed information is given about the process according to the invention.

Figure 1 shows how lignocellulosic material in the form of wood logs 1 are fed via chain feeders 2 up to and against the drum chipper rotor 26, the periphery of which is largely covered by a hood 4. The rotor periphery has a large number of knifes incorporated in knife holders (not shown). The number of knifes can vary between, for example, 8 and 32.

The rotor 26 rotates at a certain speed by means of drive unit 5. The drive unit may be an electric motor provided with a frequency converter. The rotor may also be driven hydraulically. The rotational speed may vary between 100 and 200 rpm giving a surface speed of the knifes in the lignocellulosic material (the wood) at 22 to 78 meters per second. Cutting speed varies with the type of lignocellulosic material. For spruce, for example, a suitable cutting speed is 68 m/s.

When the wood log 1 is brought into contact with the rotor 26 with its knives the log is divided into small pieces, usually referred to as chips. Adjacent to each knife the rotor has recesses for temporarily collecting the resulting chips. Figure 3, which is described and

commented upon below, shows in detail how this can be done. The temporarily collected chips are thrown by centrifugal force from said recesses into a chips collecting and discharging device 6, for example in the form of a screw conveyor. The chips are brought via this device's end 7 to, for example, a chips pocket or a chip bin (not shown). Samples of the produced chips are taken out of the screw conveyor 6 and brought through the conduit 8 to a chip analyser 9. After having been analysed the chips are brought back to the screw conveyor 6 via the conduit 10. The analysis consists at least of determination of the chip configuration, i.e. its length, width and thickness. Attained measurement results are transferred in a known manner, for example via a line 1 1 , to a computer 12, by means of which the entire disintegration process of the lignocellulosic material is controlled. There are a number of different chip analysers available on the market.

The disintegration process is controlled based on the obtained measurement results. Nothing needs to be done if the measurement result shows that the chips are of the desired quality. If the chip quality deviates from the desired quality it is according to the invention possible during operation, i.e. without stopping the rotor/drum chipper, to change at least one and up to three process variable(s) to obtain chips of desired quality.

The cutting/chipping angle (ε) is an important process variable. This angle is governed by input means' 2 position versus rotor 26, i.e., the inclination of input means 2 when the wood logs approaches and is brought towards the rotor 26. The input device, such as a chain feeder 2 is fixedly mounted in the end facing the rotor 26. Apart from this the chain feeder 2 is adjustable in height. This movement is performed by means of device 13, which via line 14 is in contact with the control computer 12. The device 13 may comprise a piston connected to a cylindrical rod, which at its upper end is attached to the chain feeder 2. The piston's movements up and down can be generated hydraulically or electrically. The chain feeder's 2 inclination can be varied from the horizontal (zero degrees) up to, for example, 30 degrees. Said inclination has a direct bearing on the chipping/cutting angle (ε), which can be varied in the range of 15-55 degrees. Swedish patent application 1 100109-6 shows in detail how this process variable can be varied.

The speed of rotor 26 is determined, as previously indicated, by the drive unit 5. Any known drive unit may be used. A very suitable such one is an electric motor with an associated frequency converter. Current rotation speed noted in the control computer 12. Information about changes of the rotation speed is transferred from the control computer 12 via the line 15 to the drive unit 5.

The third process variable that can be changed during operation is the T dimension, i.e. the distance between the knife edge and the wear plate, calculated according to a known formula. Figure 1 shows, very diagrammatically, how the T dimension may be changed. As previously indicated, the change/setting is preferably done by means of a rod, which can also be referred to as a camshaft, with a concentric cross- section or a cross section with stepped increasing height, which rod or camshaft is enclosed in a holder for the wear plate, which is spring biased connected to the holder and where the rod (camshaft) is rotated so that the wear plate is forced outwardly or inwardly depending on the turning direction. Figure 1 shows one end of said rod or camshaft 16 and an arm 27 connected at this end along with a guide roller 17 and a guide rail 18. This is connected to a cylindrical rod 20 which is driven upwardly or downwardly by a piston 21. This may be driven hydraulically or electrically by means of the device 22, which via line 23 is in contact with the control computer 12.

An operator monitors and controls the disintegration of lignocellulosic material, e.g. wood logs. The operator can transmit orders on how the process variables should be set by means of, for instance, a keyboard, via the line 24 to the control computer 12.

Figures 2a and 2b show the above described apparatus for changing the wear plate position, i.e. the distance from the wear plate's upper/outer surface to the centre of the rotor, during operating, in an enlarged and more detailed way.

Means resembling a crank is firmly anchored at the end of the camshaft or rod 16. This crank-like device consists of a fixed arm 27, and a rotatably mounted guide roller 17. The cylindrical rod 20 can be moved in vertical direction. The lever 19 is rotatably mounted in the plate 28, which is part of the guide rail 18. The rod 20 is connected to the lever 19 by the object 29. As shown in Figure 2b, the guide rail 18 is located in the free space (gap) between the cover 4 and the rotor 26. The position of the camshaft or rod 16 can be varied, depending on how the cross-section of rod 16 is formed. It has been found suitable to use three positions. In full operation, the rotor has a rotation speed of, for example, over 100 revolutions per minute. In Figure 2a the crank-like means occupies a left position which also can be designated as an initial or first position. The crank-like means consisting of the fixed arm 27 and rotatably mounted guide roller 17 follows the rotor 26 during its rotation and passes through the guide rail 18 at each lap. Usually the passage is clear but it does not matter if the guide roller 17 touches the left part of the inside of the guide bar 18.

If it is desired to continue to a third position in which the crank device ends up in a right hand position then the guide rail 18 is moved further to the right by means of the apparatus parts 20, 29 and 19. The crank device, consisting of the arm 27 and the guide roller 17, is moved from right to left in a similar way, the only difference being that the guide roller in the case hits the right part of the guide rail 18. In the first described case, i.e. from left to right, the guide roller 17 hits the left part of the guide rail 18. Once the camshaft 16 with the associated wear plate 25 has assumed a new position the rotational speed of the rotor is increased to that prevailing before the temporary lowering of the rotor or drum 26 rotation speed.

The piston 21 is firmly anchored to the cap 4 by means of fastening device 3. Next to each wear plate is a knife 30 applied along the rotor or drum 26 periphery.

Figures 2a and 2b only shows an apparatus layout for performing the desired rotation of the camshaft or rod 16. If the rotor or drum 26 width is moderate, it is sufficient that the apparatus arrangement is applied on only one side of the rotor or drum 26. For bigger drum chippers, where the rotor width is considerable, it is appropriate and in certain cases necessary to apply the displayed equipment line-up on both sides of the rotor 26, i.e. at each end.

Figure 3 shows the above frequently referred wear plates 25 clearly. As seen, the trailing or lower end of the wear plate 25 rotatably mounted and attached at position 31 . The upper or front end of the wear plate 25 changes the vertical position according to how the camshaft or rod 16 is rotated. A bolt 32 (or more) is in one end of it attached to the wear plate 25. The other end of the bolt is enclosed in a cylindrical sleeve 33 which is a recess in the exterior part of rotor 26. The other end of the threaded bolt 32 is enclosed by a spring 34. On top of the spring 34 is a washer held in place by a nut 35. It is possible to regulate the force by which the front end of wear plate 25 bears against the cross-section profiled camshaft or rod 16 by tightening or loosening the nut 35. The camshaft (rod) 16 is rotated in the above described manner so that it rests against the inside of the wear plate 25 in the desired manner. The front upper corner 36 of the wear plate 25 occupies a changed position relative to the corner of the knife 30 for each rotation of the camshaft or rod 16. Above it has been stated that the number of positions preferably is three, but it is easily realized that by amending end cross-section of the camshaft or rod 16 the number of positions may also be, for example, 2, 4 or 5.

Swedish patent application 1000181 -6 shows an alternative design of the camshaft or rod 16. Much of what is disclosed in this document is relevant and provides a basis for some aspects of the present invention.

Wood chips are released from, for example, a wood log by the knife 30, and these wood chips are collected in the channel 37 and brought out through this channel to the outlet 38. Figure 1 of the above cited document schematically shows how this may be done, and Figure 4 in this document shows the output of the chips. Figure 1 of the present patent application shows how the chips are collected in a device 6 after output. It is preferred that the channel 37 has a widening cross-section from its start at the knife 30 and the opposite tip 36 on the wear plate 25 to the outlet 38. More to read and learn regarding this specific moment could be found in Swedish patent 527294 (0200600-5). At the start of the drum chipper the operator knows the nature of the lignocellulosic material to be comminuted. If it is, for instance, pine wood obtained from trees grown in, for example, the middle part of Sweden, then the operator knows which properties that type of lignocellulosic material has. The operator also knows for what purpose the wood chips are to be used, for example for the production of chemical pulp, such as sulphate pulp. With this knowledge in the head or input into a computer the operator can set the appropriate process variables, such as the inclination of the input device 2 (see Figure 1 of the present patent application) which inclination in turn affects the chipping angle and the cutting speed as well as the T dimensions (the distance between the knife edge and wear plate determined according to known formula). The resulting wood chips are analysed intermittently or continuously for determination of their quality. If the operator finds that it has emerged a quality of the produced wood chips that deviates from the expected, then the operator changes relevant process variable or relevant process variables in accordance with the present invention. The uniqueness of this is that the change(s) is/are made during the operation of the drum chipper, i.e. the drum chipper does not have to be stopped, leading to lost productivity, and further the chip quality is improved, because the operator can instantaneously alter one or more process variable(s) without having to think about that a stop leads to production loss. According to prior art, the operator needs to stop the drum chipper to change the process variables.

Claims

1 . A process for disintegrating elongated lignocellulosic material (1 ) in an apparatus in the form of a drum chipper with connecting input means (2) for the purpose of achieving a predetermined quality of the disintegrated lignocellulosic material, comprising

- feeding the elongated lignocellulosic material (1 ) to the drum chipper that consists of a stand carrying a horizontal and rotatable drum/rotor (26), the periphery of which has a plurality of knifes (30) contained in knife holders as well as with every knife interacting radially adjustable wear plates (25) positioned at a certain distance from the knife (30) and its edge, and a space (37,38) for temporarily collecting the disintegrated lignocellulosic material, said space (37,38) being positioned between each knife (30) and one or more anvil steels that interact(s) with each respective knife (30), said anvil steel(s) preferably being attached to the stand, and

- manually or instrumentally, intermittently or continuously analysing (9) the outputted disintegrated lignocellulosic material primarily regarding its configuration, characterised in that

- at least one process variable is changed during operation by

- setting a certain chipping angle (ε) by regulation of input means' (2) position vis-a-vis the rotor (26) causing the fed elongated lignocellulosic material (1 ) to approach and be brought towards the rotor (26) at a certain angel and/or

- setting a certain T dimension value (distance between the knife edge and the wear plate (25) calculated according to a known formula) by changing the wear plate's (25) radial distance from the rotor's (26) centre, preferably after temporary lowering of the rotor's (26) speed and/or

- setting a certain cutting speed, i.e. knife speed through the

lignocellulosic material (1 ), by changing the rotor's (26) speed.

2. The process according to claim 1 , characterised in that

- the elongated lignocellulosic material (1 ) is fed to the rotor (26) via an elongated chute device, the front end of which is rotatably mounted in a stand, and which chute device at a distance from the front end is equipped with lifting and lowering means, which is/are attached to the chute device as well as the stand, and which means work automatically and preferably following instructions through a computer (12).

3. The process according to claim 1 , characterised in that

- the elongated lignocellulosic material (1 ) is fed to the rotor (26) by means of conveyor means (2), the front end of which is rotatably mounted in a stand, and which conveyor means (2) at a distance from the front end is equipped with lifting and lowering means (13), which is/are attached to the conveyor means (2) as well as the stand, and which means (13) work automatically and preferably following instructions through a computer (12).

4. The process according to claim 3, characterised in that

- the elongated lignocellulosic material (1 ) after conveyor means (2) in the transport direction is passed over and in connection to anvil steel arranged at an inclination corresponding to the inclination of conveyor means (2).

5. The process according to claim 1 , characterised in that

- during the feeding of the elongate lignocellulosic material (1 ), usually of cylindrical shape, the object is brought to pass a measuring device that determines the height of the object, usually its diameter, and if said height exceeds a predetermined value, then said angle (inclination) is set so as to minimize the chipping angle.

6. The process according to claim 1 , characterised in that

- the generated comminuted lignocellulosic material is collected in a duct with a first opening at the knife's (30) edge and which extends towards the rotor's (26) centre and which then deflects towards the periphery of the rotor (26) with its second opening in the rotational direction after the knife (30), and

- the breadth and T dimension of the first opening is set by means of an adjustment device, preferably in the form of a rod (16) with a concentric cross section or a cross section with stepwise increasing height, said rod being enclosed in a holder for the wear plate (25), which is spring-loaded connected (32, 33, 34 and 35) to the holder, and the rod's (16) outwardly facing side rests against the wear plate's (25) inner side, and

- said setting is achieved by turning the rod (16) so that the wear plate (25) is forced outwards or inwards depending on the turning direction, which rotational motion is automatic and preferably following instructions through a computer (12).