DE10119182A1 - Continually-operated cellulose digester is inclined to the horizontal with lower inlet and upper outlet - Google Patents

Abstract

A continually-operated tubular cellulose (1) digester (3) assembly has an impregnation unit (2). The digester has a helical drive (5) advancing cellulose from the inlet (6) to the digester outlet (7). The digester longitudinal axis (4) is inclined at between 3 and 40 to the horizontal. The digester inlet (6) is at the lower end and the outlet is at the upper end. Also claimed is a commensurate process with a first helical feed (5) has a hollow shaft (37) with injection outlets (60) releasing chemicals into the cellulose mass between the inlet and outlet. The shaft (37) has a displacement body which regulates the chemical discharge. The body has an axial drill hole (71) with an inlet (72) and radial outlets (73). the body also has bearing rings (74).

Description

The invention relates to an apparatus and a method for continuous cooking of cellulosic raw material, in particular a pulp cooker or a process for pulp cooking.

Pulp cooker, usually referred to as "digester" in English, can process the raw material either in batches digesting ", or continuously fed and accordingly be emptied continuously. The so-called "batch digesters" use in the Rule as the actual cooker is one that extends vertically Hollow body into which the raw material and chemicals are filled and after closing the hollow body temperature and pressure increased to boil the pulp out of the raw material. Also for Batch digester has been a major effort to use effectively of energy and chemicals. The US shows 5,080,757 a vertical "batch digester" in which the discharged from the cooker usually inorganic chemicals, sometimes in parallel processes continue to be used. The US 5,059,284 shows the removal of the Chemicals from the vertical cooker by pumping in at the same time of liquid above and below.  

US 5,059,281 shows an improved emptying of the vertical batch digester "by cyclically opening and closing the exhaust valve. The US 5,015,333 shows the removal of so-called "black liquor" at the top Cooker by pumping liquid into the bottom of the cooker. US 4,849,052 shows a multi-stage cooking of a vertical batch digester "with chemical exchange. US 4,601,787 shows a process for accelerated heating of a vertical "batch digester".

Continuous cookers have the advantage of taking up less space and higher efficiency in terms of energy used and Chemicals. Vertical continuous cookers are known, see US 5,256,255, and horizontal cookers, see US 2,616,802. At the the latter stove prevails both in the actual cooking zone ("intermediate zone B") as well as in the outlet area ("discharge zone") temperature and pressure higher than the atmosphere. In particular due to the overpressure in the cooker and the resulting pressure related security requirements also have continuous Cookers still require a lot of energy and space.

US 2,821,476 shows a device for equalizing the Material flow in a cooker. US 4,564,443 and US 5,769,243 show facilities connected to the stove for further Treatment of the cellulose-enriched raw material pulp.

The invention is based on a device for continuous cooking of cellulosic and especially vegetable raw material an impregnation device for impregnating the raw material and one tubular cooker with one around a longitudinal axis of the cooker  rotating first screw conveyor that feeds the raw material from an inlet to an outlet of the cooker as described in "Handbook of Pulping and Papermaking, ISBN 0-12-097362-6, Academic Press Ltd., 2nd ed. 1996, Page 75 ff under the PANDIA brand. The horizontal each aligned cooker tubes are side by side or one above the other arranged. They are connected to one another at their ends and form a meandering stove structure. The same in this document described continuous cooker M & D (brass & Durkee) closes with the horizontal an angle of 45 °. One in the middle and partition plate extending over the entire axial length ("midfeather plate") separates the cooker into two each semicircular cylindrical sub-rooms through which in the manner of an escalator Bucket conveyor is endlessly moved. That about the Raw material introduced at the top inlet is by means of the Bucket conveyor down once and then back to also transported overhead outlet. The cooking time is approximately 30 minutes.

The invention is based on the problem of a device and a Process for the continuous cooking of raw material containing cellulose to provide a high yield with good pulp quality provides and at the same time a high efficiency of the energy used and chemicals and has a small footprint. The problem is by the device defined in claim 1 and in secondary claim solved certain procedures. Special Embodiments of the invention are defined in the subclaims.

The fact that the longitudinal axis of the stove with the horizontal one includes an acute angle between 3 ° and 40 ° and that the inlet at  a lower end portion of the cooker and the outlet at an upper one End section of the cooker is arranged, on the one hand, high efficiency of the cooking process, in particular a high cellulose yield, with low Use of energy and chemicals guaranteed. In addition, the selected angle with respect to the horizontal of the space requirement reduced, especially in the vertical. The one by gravity causes the chemical to return towards the inlet especially with simultaneous operation of the first screw conveyor homogeneous mixing of the raw material pulp. In the device there is essentially atmospheric or ambient pressure. The tempering of the raw material pulp is preferably carried out above all or solely by the temperature of the chemical introduced. Alternatively or in addition to this, the cooker can have a double jacket Have heating, for example by means of heating steam, thermal oil and / or pressurized water. The temperature and concentration of the Chemicals should be chosen so that the yield and / or quality of the the cellulose-containing raw material to be obtained Specifiable requirements are sufficient, for example for further Processing in the paper industry. Among other things, To reduce the proportion of other substances in the raw material, for example lignin or extract from the raw material.

The fact that the first screw conveyor on a coaxial to the longitudinal axis is arranged first hollow shaft, which has first injection openings for Injecting chemicals in a radial direction on the outer surface of the connecting first hollow shaft and axially between the inlet and the Outlet arranged reaction space of the cooker, the chemicals can targeted and with the required temperature at the points in the Raw material can be mixed in, which is an energy-efficient high yield  of pulp. In particular, the injection openings near the upper and / or lower axial end of the reaction space arranged or distributed over the entire axial length. The one at the top End-injected chemicals also migrate partially under effect the gravitational force against the movement of the first screw from top to bottom and mix with the raw material pulp. The chemicals injected at the lower end ensure an early chemical reaction as soon as the raw material pulp enters the cooker. In particular, the temperature of the raw material pulp is already at Entry into the cooker adjustable. The hollow shaft is preferred circular cylindrical. In any case, the hollow shaft is an alternative to this sectionally conical.

Characterized in that a displacement body is arranged in the first hollow shaft, which preferably has an axial bore with an inflow opening for the chemicals and radial outflow openings 73 for the outflow of the chemicals into the first hollow shaft, the location and / or the volume flow is that in the Reaction chamber injected chemicals adjustable. The displacer body is preferably supported on the inside of the first hollow shaft by means of a plurality of bearing rings which are axially spaced apart and formed in one piece. For example, it can be stationary with respect to the first hollow shaft or rotate together with it about its longitudinal axis.

Characterized in that the reaction space is essentially ring-cylindrical and is delimited radially on the outside by a cylindrical reaction tube Has outlet openings for the exit of the chemicals from the Reaction space, the chemicals are after a specifiable residence time removable from the reaction space and after a corresponding  Reprocessing, especially with regard to temperature and chemical Composition, can be returned to the reaction space. The openings are preferably near the lower and / or upper end of the Reaction space arranged. In any case, in this area a Outer jacket surrounding the reaction space, preferably a circular cylindrical outer tube, discharge openings on with a pump are connected. This is with one at the top of the hollow shaft attached connection device for reintroducing the chemicals connected in the reaction space.

The fact that at the upper end of the reaction space counter pressure device can be applied, which is a obstacle that can be overcome, but creates a back pressure between the reaction chamber and the outlet of the cooker is in Reaction space build up a dynamic pressure. The force is applied preferably via pneumatic cylinders with one end on one Support the flange of the outlet and its other end to the Support the counter pressure plate. This plate can also be plate-shaped be trained. In particular, the counter pressure plate is on one Sleeve element arranged that sliding on the first hollow shaft is movable.

Preferably, the first screw extends from the inlet to the Reaction space, in particular up to the upper end of the reaction space, the slope of the first screw is greater in the inlet than in Reaction chamber. This results at the inlet end of the Reaction space a compression of the raw material pulp.  

There is preferably one between the inlet and the impregnation device supporting the filling of the cooker with the raw material Darning device arranged. Inlet and impregnation device are over a chute extending substantially in the vertical direction connected, in which the stuffing device in the form of a stuffing screw inlet end enters. The pitch of the stuffing screw corresponds to essentially the slope of the first screw conveyor in the inlet area. The The longitudinal axis of the stuffing auger closes with the longitudinal axis of the first Screw conveyor an acute angle, in particular between 50 ° and 60 °. The imaginary extension of the axis of the stuffing screw cuts the Axis of the first screw near the reaction chamber near the end of the Inlet. The inlet has second outlet openings on its underside for the exit in particular in the impregnation device chemicals brought in, which are usually a lower temperature and / or have a different composition than that in Reaction chamber chemicals used.

The impregnation device preferably has a tubular one Screw conveyor with one arranged on a second hollow shaft second screw conveyor, which has a filling chamber over a Impregnation room connects with a transfer room. The second The screw conveyor is oriented essentially horizontally. about the cellulose-containing raw material is fed into a filling shaft. Filling room poured in. The chute closes at the transfer room to the stove inlet.

The second hollow shaft has a second one in the section of the impregnation chamber Injection ports for injecting chemicals or Impregnation of the raw material. The chemicals are about that  Filling chamber end of the second hollow shaft can be introduced. Further Openings for the introduction of chemicals, if necessary also gaseous or spray-like, are on top of the Impregnation device over the transfer space and / or at one Side wall of the chute arranged.

The slope of the second screw conveyor is in the section of the filling chamber larger than in the section of the impregnation space, which results in a Compression of the raw material at the beginning of the impregnation room results. The device is such in terms of the materials used designed that for cooking the especially from annual plants or vegetable waste products of existing raw material formic acid and Hydrogen peroxide, optionally in aqueous solution, can be used. For this purpose, the individual is in contact with the chemicals coming parts of the device preferably made of steel or stainless steel manufactured. As far as plastic parts are used, they exist preferably made of polytetrafluoroethylene (PTFE).

The problem underlying the invention is also due to a method for the continuous cooking of cellulose-containing raw material, at which first impregnates the raw material in an impregnation device and then the impregnated raw material in a tubular Cooker with a first rotating about a longitudinal axis of the cooker Screw conveyor that moves the raw material from an inlet to an outlet the cooker is transported, cooked, characterized in that while cooking the raw material from below, at an angle between 3 ° and 40 ° with respect to the horizontal, upwards at an angle is promoted. The above applies to the advantages Device called. The chemicals required for cooking  are via openings in a first carrying the first screw Hollow shaft injected into a reaction chamber of the cooker. about Appropriate outlet openings and collecting agents can the chemicals removed from the reaction space and reprocessed, in particular the temperature is set to a predeterminable value. The processing of the chemicals includes, in particular, a separation of the soluble components such as lignin, terpenes or acetic acid. Depending on the application, the composition of the Chemicals checked and hired, which subsequently followed the procedure be fed again.

Further advantages, features and details of the invention result from the dependent claims and the following description in which with reference to the drawings, an embodiment in individual is described. The can in the claims and in the Description mentioned features each individually or in any combination be essential to the invention.

Fig. 1 shows a schematic overview of a system for producing pulp with an inventive device,

FIG. 2 shows an enlarged and more detailed section of the device of FIG. 1 in the area of the impregnation device,

Fig. 1 3 shows an enlarged detail of the apparatus of Fig. In the region of the digester,

Fig. 4 shows a middle piece of a in the first hollow shaft arranged displacement body,

Fig. 5 shows an initial part of the displacement body with a total of three bearing rings and one of the upper end of the reaction space associated first bearing journal,

FIG. 6 shows an end piece of the displacement body, with a total of two bearing rings and a second bearing pin assigned to the lower end of the reaction space, and

Fig. 7 shows the space-saving arrangement of several stoves in a row.

Fig. 1 shows a schematic overview of a plant for producing pulp with an inventive device for continuous cooking of cellulose-containing raw material 1, with an impregnation device 2 for impregnation of the raw material 1 and a tubular boiler 3 with a rotating about a longitudinal axis 4 of the digester 3 first screw conveyor 5 , which conveys the raw material 1 from an inlet 6 to an outlet 7 of the cooker 3 . The longitudinal axis 4 forms an acute angle with the horizontal, in the illustrated embodiment of approximately 15 °. So-called annual plants, such as wheat straw, rice straw, hemp, flax, bagasse, kenaf and the like, or woods, such as spruce, pine, fir, birch, beech, eucalyptus and the like, can in particular be used as the raw material.

The raw material 1 can be introduced into a filling space 9 of the impregnation device 2 via a filling shaft 8 . A second screw conveyor 10 conveys the raw material 1 in the impregnation device 2 to a transfer space 11 , at which a chute 12 connects the impregnation device 2 to the cooker 3 . At the cooker end of the chute 2 , a stuffing device 13 is arranged. This stuffs the falling impregnated raw material into the inlet 6 of the cooker 3 . From there it is conveyed upwards through a central reaction chamber 14 into the upper outlet 7 by overcoming a counter pressure device 15 . From there it falls via a further chute 16 either into a further stove 3 a, 3 b, connected in cascade. , ., 3 y, 32 ( FIG. 7) or in a first further treatment device 17 , for example for dewatering, deacidifying, de-lignifying, cleaning or the like, which is followed by a second further treatment device 18 and possibly further ones.

FIG. 2 shows an enlarged and more detailed section of the device of FIG. 1 in the area of the impregnation device 2 . This has the second screw conveyor 10 arranged in a stainless steel tube 19 of the screw conveyor, which has a greater slope in the section of the filling chamber 9 than in the section of the impregnation chamber 20 . The ratio of the gradients is preferably about 3: 2. The second screw conveyor 10 is arranged on a second hollow shaft 21 which passes through the filling chamber 9 , the impregnation chamber 20 and the transition chamber 11 . At the end near the transition space, a second drive unit 22 is flanged to the tube 19 and has a second electric motor 23 , which is controllable in its speed, and a second gear 24 .

The gear reduction is selected, for example, so that the speed of the second hollow shaft 21 is between 0.1 and 1 revolutions / minute, preferably about 0.4 revolutions / minute. The residence time of the raw material 1 in the impregnation chamber 20 is, for example, between 15 and 90 minutes, for annual plants preferably between 15 and 30 minutes, for woods preferably between 15 and 45 minutes.

At the end of the filling chamber, the filling shaft 8 is arranged on the pipe 19 , preferably flange-mounted. The second hollow shaft 21 emerges at the end of the impregnation device 2 opposite the second drive unit 22 and forms a second connection device 25 for chemicals to be injected into the impregnation device 2 . These are guided axially in the second hollow shaft 21 and enter the impregnation chamber 20 via second injection openings 26 . The second injection openings 26 are preferably evenly spaced and their number corresponds to the number of turns of the second screw conveyor 10 . In the area of the transition space 11 , the impregnation device 2 has a third connection device 27 for injecting chemicals above the chute 12 . Furthermore, a fourth connection device 28 for injecting chemicals is arranged on the circumference of the chute 12 . Formic acid vapor, water vapor and / or hydrogen peroxide are preferably injected into the impregnation device 2 . The third connection device 27 is preferably used to inject the chemical removed in the region of the inlet 6 of the cooker 3 and guided by a first pump 29 ( FIG. 1) and a first heat exchanger 30 for the purpose of tempering, in particular the raw material 1 is steam sprayed with formic acid. Injecting the chemical in the impregnation device 2 serves in particular to wet and moisten the raw material 1 so that it can be converted more effectively by the chemicals used there in the subsequent cooker 3 .

FIG. 3 shows an enlarged section of the device of FIG. 1 in the area of the cooker 3 . Selected from the impregnator 2 is supplied via the chute 12 soaked raw material is stuffed into by means of a stuffing arrangement 13 which is arranged on a side wall of the widening in this area the chute 12 into the digester. 3 The stuffing device 13 has a third electric motor 32 , a third gear 33 and a stuffing screw 34 .

The longitudinal axis 4 of the cooker 3 includes an acute angle between 3 ° and 40 ° with the horizontal, in the illustrated embodiment of approximately 15 °. With the stuffing screw axis 36 , the longitudinal axis 35 likewise encloses an acute angle between 30 ° and 75 °, in the illustrated embodiment of approximately 55 °. In the area of the inlet 6 of the cooker 3 assigned to the chute 12 , the first screw conveyor 5 arranged on a first hollow shaft 37 has a greater gradient than in the reaction chamber 14 which adjoins in the upward direction. The ratio of the gradient is approximately 2: 1. The gradient of the first screw conveyor 5 in the area of the inlet 6 corresponds approximately to the gradient of the stuffing screw 34 or is slightly smaller. A first drive unit 38 is flanged to the lower end of the inlet 6 and has a first electric motor 39 , the speed of which can be regulated, and a first transmission 40 . The drive takes place via a pin-like extension of the first hollow shaft 37 which is led out of the inlet 6 at a speed between 0.1 and 1 revolutions / minute, preferably about 0.4 revolutions / minute. The inlet 6 is essentially formed by an inlet pipe 41 which has flanges at its ends and has outlet openings 42 on its underside for the outlet of chemicals. These are collected in a trough 43 and can be removed via an outlet connection 44 and fed back to the device, in particular the third connection device 27 of the impregnation device 2 ( FIG. 2).

By blasting, convection, evaporation, spraying via the third connection device 27 and / or other active cooling, the temperature of the raw material 1 already mixed with chemicals is reduced in the region of the chute 12 and / or the inlet 6 , for example to approximately 25 ° C. This leads to a chemical drift in the raw material 1 and the impregnation of the raw material 1 with the chemicals is improved, which leads to a higher efficiency of the subsequent pulp boiling. At the lower end of the inlet 6 , a chemical sump is formed, which additionally leads to the raw material 1 being wetted again with the chemicals.

At the inlet 6 , the reaction chamber 14 formed, among other things, by the cylindrical reaction tube 45 made of stainless steel. The reaction tube 45 has outlet openings 46 on its underside at the lower and upper ends of the reaction space 14 . Chemicals can escape from the reaction chamber 14 via these and are collected by an outer tube 47 which is coaxial with the reaction tube 45 and which has a connecting piece 48 near its lower end for removing the chemicals. The residence time of the raw material to be treated in the reaction chamber 14 depends in particular on the composition of the chemicals, the temperature and the raw material used. Typical dwell times in the boil are in the range between 15 minutes and 12 hours, for annual plants preferably between 60 minutes and 2.5 hours, for woods preferably between 60 minutes and 6 hours.

The reaction chamber 14 is connected in the upward direction to the outlet 7 , which essentially consists of an outlet pipe 49 which has a flange on both sides and has a further chute 16 on the underside. At the upper axial end, a counterpressure device 50 is flanged to the outlet pipe 49 , which has two pneumatic cylinders 51 , each of which is fixed to the axially upper flange of the outlet pipe 49 via a clevis connection 52 . The respective other end of the pneumatic cylinder 51 is fixed via a further fork head connection 53 to a flange 54 of a sleeve element 55 which is slidable on the first hollow shaft 37 . At its end facing the reaction chamber 14 , the sleeve element 55 has a counter-pressure plate 56 which partially closes the reaction chamber 14 . Although the cooking of the raw material pulp in the reaction space 14 takes place essentially under atmospheric pressure, a back pressure can be built up by the counter-pressure plate 56 , which leads to an overall squeezing out of the chemicals from the raw material pulp before it leaves the cooker 3 via the further chute 16 .

The extracted through the connection piece 48 are chemicals via a second pump 57 (FIG. 1) and a second heat exchanger 58 to the reaction chamber 14 again can be fed via a disposed at the upper end of the first hollow shaft 37 fifth terminal device 59. For this purpose, the first hollow shaft 37 has first injection openings 60 at the lower and upper ends or distributed over the entire axial length of the reaction space 14 . These are preferably axially evenly spaced, the distance corresponding to the pitch of the first screw conveyor 5 in the exemplary embodiment shown. Before or after the second pump 57 or the second heat exchanger 58 , fresh, unused and / or recycled chemicals can be fed to the chemical circuit from corresponding storage containers 61 . The reprocessing of the chemicals includes, in particular, a separation of the dissolved ingredients, such as lignin or terpenes, which can be sent for further processing.

Temperature measuring and / or temperature regulating devices 62 and / or measuring devices 63 for determining the chemical composition of the chemicals used are arranged in the impregnation device 2 , in the chemical circuit and / or in the cooker 3 . These are connected to a central process control which, taking into account the type, moisture and size of the filled raw material 1 , the gradients of the first and second conveyor screws 5 , 10 and the requirements for the pulp to be produced, the first, second and third electric motors 23 , 32 , 39 taxes. In addition, the central process control regulates the temperature of the chemicals used, which can be predetermined by means of the heat exchangers 30 , 58 .

FIG. 4 shows a center piece 75 of a displacement body arranged in the first hollow shaft 37 , by means of which the location and / or the volume flow of the chemicals injected into the reaction space 14 can be adjusted. The center piece 75 has a continuous axial bore 71 through which the chemicals can be fed to the displacer. On its outer circumferential surface, the center piece 75 preferably forms in one piece a plurality of equidistant bearing rings 74 , by means of which the center piece 75 is supported on the inner surface of the first hollow shaft 37 . Two bearing rings 74 each delimit an essentially circular cylindrical cavity 76 , which is connected to the axial bore 71 via radial outflow openings 73 . In the area of the radial outflow opening 73 , the outer circumferential surface of the displacer body has a groove 77 which in the exemplary embodiment is circumferential and has a curvature in cross section, which serves for better distribution of the chemicals in the annular cylindrical cavity 76 . Otherwise, the outer circumference of the displacement body in the area between two bearing rings 74 is essentially cylindrical, in particular circular cylindrical. Alternatively, the outer peripheral surface can also be conical, for example at an angle of <3 °. A total of five bearing rings 74 of the center piece 75 in the exemplary embodiment shown form four circular-cylindrical cavities 76 , through which the chemicals flowing into the bore 71 reach the reaction chamber 14 through corresponding first injection openings 60 of the first hollow shaft 37 .

FIG. 5 shows an initial piece 78 of the displacement body with a total of three bearing rings 74 and a first bearing pin 79 assigned to the upper end of the reaction space 14 . The starting piece 78 also has an axially continuous bore 71 with an inflow opening 72 at the end, which is connected to the circular-cylindrical cavities 76 via corresponding outflow openings 73 . The axial distance between the bearing rings 74 in the starting piece 78 is slightly, for example about 10%, greater than the distance between the bearing rings 74 in the middle piece 75 . The axial length of the first journal 79 corresponds approximately to the axial length of a circular cylindrical cavity 76 . The diameter of the outflow opening 73 is slightly smaller in the starting piece 78 , for example about 20%, than in the middle piece 75 . The axial extent of the circumferential groove 77 corresponds approximately to the diameter of the outflow opening 73 .

FIG. 6 shows an end piece 80 of the displacement body, with a total of two bearing rings 74 and a second bearing pin 81 assigned to the lower end of the reaction space 14 . The axial bore 71 , which preferably has the same diameter in the start piece 78 , middle piece 75 and end piece 80 , is designed in the end piece 80 as a blind hole which ends in the second bearing pin 81 . The distance between the bearing rings 74 in the end piece 80 is reduced compared to the corresponding distance in the middle piece 75 , for example by about 30%. The width of the bearing rings 74 is also reduced in the end piece 80 compared to the middle piece 75 , for example by approximately 25%. In contrast, the diameter of the outflow opening 73 is larger in the end piece 80 than in the middle piece 75 , for example by about 40%. As an alternative to this, the axial spacings of the bearing rings 74 , the width of the bearing rings 74 and / or the diameter of the outflow openings 73 in the start piece 78 , middle piece 75 and end piece 80 may be identical, in particular the representations in this regard in FIGS. 4 to 6 are not to scale.

The displacement body can also be made in one piece and preferably consists of a plastic which is sufficiently resistant to the chemicals used, for example polytetrafluoroethylene (PTFE). With its first and second bearing journals 79 , 81 , the displacer body is mounted in the cooker 3 and in particular in the first hollow shaft 37 and can be stationary or rotate at a lower, equal or higher speed than the first hollow shaft 37 . The axial length required for the displacement body can be achieved if necessary by stringing together a sufficient number of center pieces 75 . The outer diameter of the displacer body in the region of the annular cylindrical cavities 76 can be constant over the axial length of the displacer body or can vary in particular in the direction of the end piece 80 or the second bearing journal 81 , in particular increase in order to achieve the flow velocities in the first injection openings required for the respective application 60 and thus to adjust the inflow of chemicals into the reaction chamber 14 . By axially displacing the displacement body in the first hollow shaft 37 , the location and quantity of the chemicals flowing into the reaction space 14 can also be controlled.

Fig. 7 shows the space-saving arrangement of several cookers 3 , 3 a, 3 b,. , ., 3 y, 32 in a row. For reasons of clarity, neither an impregnation device 2 nor a further treatment device 17 is shown in FIG. 7. Each of the cookers 3 , 3 a, 3 b, 3 y, 32 conveys the raw material 1 from the lower inlet 6 , 6 a, 6 b, 6 y, 62 to the higher outlet 7 , 7 a, 7 b,. , ., 7 y, 72 . From the outlet 7 of the first cooker 3 , the raw material 1 falls into the inlet 6 a of the second cooker 3 a, etc. until it can lastly be removed from the outlet 72 of the last cooker 32 and optionally one of the further treatment devices 17 , 18 of FIG. 1 can be fed. The height of such a device according to the invention for the continuous cooking of cellulose-containing raw material is essentially determined by the height of an individual cooker 3 and is thus significantly reduced compared to the prior art. The inventive zigzag arrangement of the individual cookers 3 , 3 a, 3 b,. , ., 3 y, 32 in addition, the width and length of the system is relatively small. The distance of the inlet 6 of the first cooker 3 to the inlet 6 b of the next but one cooker 3 b is preferably less than the simple axial length of the cookers 3 , 3 a, 3 b, which are preferably of identical construction. , ., 3 y, 32 .

Claims (19)

1. Device for the continuous cooking of cellulose-containing raw material ( 1 ), in particular cellulose extraction device, with an impregnation device ( 2 ) for impregnating the raw material ( 1 ) and a tubular cooker ( 3 ) with a rotating around a longitudinal axis ( 4 ) of the cooker ( 3 ) first screw conveyor ( 5 ), which conveys the raw material ( 1 ) from an inlet ( 6 ) to an outlet ( 7 ) of the cooker ( 3 ), characterized in that the longitudinal axis ( 4 ) of the cooker ( 3 ) is one with the horizontal Includes angle between 3 and 40 ° and that the inlet ( 6 ) is arranged at a lower end portion of the cooker ( 3 ) and the outlet ( 7 ) at an upper end portion of the cooker ( 3 ). 2. Apparatus according to claim 1, characterized in that the first screw conveyor ( 5 ) on a longitudinal axis ( 4 ) coaxial first hollow shaft ( 37 ) is arranged, the first injection openings ( 60 ) for injecting chemicals in a radial to the Outer surface of the first hollow shaft ( 37 ) and reaction chamber ( 14 ) of the cooker ( 3 ) formed axially between the inlet ( 6 ) and the outlet ( 7 ). 3. Apparatus according to claim 2, characterized in that a displacement body is arranged in the first hollow shaft ( 37 ), by means of which the location and / or the volume flow of the chemicals injected into the reaction chamber ( 14 ) can be adjusted. 4. The device according to claim 3, characterized in that the displacer has an axial bore ( 71 ) with an inflow opening ( 72 ) for the chemicals and radial outflow openings ( 73 ) for the outflow of the chemicals into the first hollow shaft ( 37 ). 5. Apparatus according to claim 3 or 4, characterized in that the displacer has axially spaced bearing rings ( 74 ) with which the displacer is in contact with the first hollow shaft ( 37 ). 6. Device according to one of claims 2 to 5, characterized in that the reaction chamber ( 14 ) is substantially ring-cylindrical and is delimited radially on the outside by a cylindrical reaction tube ( 45 ) which has outlet openings ( 46 ) for the exit of the chemicals from the Reaction space ( 14 ). 7. Device according to one of claims 2 to 6, characterized in that at the upper end of the reaction chamber ( 14 ) a counterpressure device ( 50 ) can be applied, which an obstacle which can be overcome but generates a counterpressure between the reaction chamber ( 14 ) and the outlet ( 7 ) of the cooker ( 3 ). 8. The device according to claim 7, characterized in that the counter pressure device ( 50 ) on the first hollow shaft ( 37 ) slidably displaceable back pressure plate ( 56 ). 9. Device according to one of claims 2 to 8, characterized in that the first screw conveyor ( 5 ) extends from the inlet ( 6 ) to the reaction chamber ( 14 ), and that the slope of the first screw conveyor ( 5 ) in the inlet ( 6 ) is larger than in the reaction space ( 14 ). 10. Device according to one of claims 1 to 9, characterized in that between the inlet ( 6 ) and the impregnating device ( 2 ) is arranged a filling device ( 13 ) supporting the cooker ( 3 ). 11. The device according to one of claims 1 to 10, characterized in that the impregnation device ( 2 ) has a tubular screw conveyor with a on a second hollow shaft ( 21 ) arranged second screw conveyor ( 10 ) and that the screw conveyor has a filling chamber ( 9 ) via a Impregnation space ( 20 ) connects to a transfer space ( 11 ). 12. The apparatus according to claim 11, characterized in that the second hollow shaft ( 21 ) in the section of the impregnation chamber ( 20 ) has second injection openings ( 26 ) for injecting chemicals. 13. The apparatus of claim 11 or 12, characterized in that the slope of the second screw conveyor ( 10 ) in the section of the filling chamber ( 9 ) is greater than in the section of the impregnation chamber ( 20 ). 14. Device according to one of claims 1 to 13, characterized in that formic acid and hydrogen peroxide can be used for cooking the raw material 1 in the cooker ( 3 ). 15. A process for the continuous cooking of cellulose-containing raw material ( 1 ), in particular cellulose cooking, in which the raw material ( 1 ) is first impregnated in an impregnation device ( 2 ) and then the impregnated raw material in a tubular cooker ( 3 ) with a around a longitudinal axis ( 4 ) of the cooker ( 3 ) rotating first screw conveyor ( 5 ), which conveys the raw material ( 1 ) from an inlet ( 6 ) to an outlet ( 7 ) of the cooker ( 3 ), characterized in that during cooking Raw material ( 1 ) from the bottom inlet ( 6 ), at an angle between 3 and 40 ° to the horizontal, is conveyed to the top outlet ( 7 ). 16. The method according to claim 15, characterized in that the chemicals required for cooking are injected via first injection openings ( 60 ) in a first hollow screw ( 5 ) carrying the first hollow shaft ( 37 ) into a reaction chamber ( 14 ) of the cooker ( 3 ). 17. The method according to claim 15 or 16, characterized in that the chemicals required for cooking are prepared, in particular the temperature is set to a predeterminable value is, and then returned to the process. 18. The method according to any one of claims 15 to 17, characterized in that the raw material ( 1 ) is brought into contact with formic acid or formic acid vapor in the impregnation device ( 2 ) upstream of the cooker ( 3 ). 19. The method of claims 15 to 18, characterized in that the impregnated raw material is cooled before entering the reaction space ( 14 ).