FI63072B - SAETT ATT SOENDERDELA OCH RAFFINERA RAOTT FIBERMATERIAL T EX TRAE - Google Patents

Description

RSKI ΓβΙ mvKULULUSJULlCAISU nn „^ j | 3 | A LbJ O ') UTLÄGG NI NGSSKRI FT 0 ^ 0 7 2 1¾¾ c (45); ·:' L 11 1983 ^ ^ (51) K» .ik.Wa · 3 DB 1/04 ·, 1/16 FINLAND — FINLAND (21) P »Mntti» «k« Tiu · —Ρ »·« αΜ «ΛιιΐΛ * 753187 (22) Htkamliplivi - Anafikninpdif 12.11.73 (23) AlkupMvl —GIW | h * t »d · * 09.01.69 (41) Gotten stuck - Hlvtt offantllg 12.11.75

Date of patent and construction of J. k.mL »lc *» nlhUvtolptnon. -

Patent- och regietentyralaen '' Anteku utlagd och utUkriftan publicurad 31.12.82 (32) (33) (31) Pyueletty etuelktut-BuiW priori ». * 11.01.68 USA (US) 697192 (71) The Bauer Bros. Co., Springfield, Ohio, USA (US) (72) Joseph C. Shouvlin, Springfield, Ohio, Raymond A. Leask, Springfield, Ohio, USA (US) (7 * 0 Berggren Oy Ab (5 * 0 Tapa for the decomposition and refining of raw fibrous matter, such as wood - Sätt att sönderdela och raffinera rätt fiber-material, t.ex. trä (62) Divided by division 66/69 (patent 5212 ^) -Avdelad frän trap 66/69 (patent 5212 ^) This invention relates to the milling of high yield pulps and is intended to provide superior fiber products in the past.

Pulp milling has been greatly developed recently and is constantly being studied. The main object of the research is the tools and methods for obtaining the highest possible yield and the best possible mass quality from the given amount of raw material at the lowest possible cost. This area of research is becoming increasingly important as our natural resources, especially forest trees, dwindle. As natural resources dwindle, commodity prices rise. One problem is the ever-increasing cost of labor required to procure and process raw materials. Add to these basic problems the fact that in a conventional grinding process, the raw material must pass through many devices, this becomes very expensive. In addition to this, a conventional grinding plant requires a lot of expensive space. Furthermore, the use of grinding equipment normally required for efficient grinding takes a considerable amount of time to obtain the required amount of pulp. All this affects the yield and its cost.

2 63072

The object of the invention is to provide a solution to the above problems and to provide a method and a system suitable for carrying out the method, which can achieve a high degree of refining with a very small number of processing units and which result in high quality pulp and long fibers insignificant. damage.

According to the invention, this is achieved in a manner which is known mainly from the features of the appended main claim 1 and by means of a system which is known mainly from the features of the appended claim 7.

The method and system according to the invention will now be described in more detail by way of example and with reference to the accompanying Figures 1 and 2, which show two different embodiments of the system according to the invention.

Corresponding parts are denoted by the same reference numerals in both figures.

The basic idea of the invention is shown in Figure 1. The double disc refiner 10 described herein has a housing with an flattened spherical inner chamber. This is determined in part by a web portion comprising wall portions 11 and 12 flattened so that their planes are parallel to the planes of the grinding blades therebetween. The parts 11 and 12 are connected by a web part 13, the shape of which is such that it is concentric and separated from the frames of the blades. The housing of the refiner has cover and bottom parts Ik, which are in the shape of a spherical segment and which are perpendicular to the web part 13.

The refiner 10 is designed to operate under fully pressurized conditions. In the example, a pressure seal is connected to the refiner inlet line to the "M&I / 'cooker through a connector defining an inclined cooker outlet. A second connector is connected to the refiner outlet, which is pressure sealed to the inlet line of the vertical scrubber tube 30. which maintains pressure at the end of the system.The inlet line of the digester 32 has a similar valve 31. When using the described system, there may be cooking liquor, such as sulphate liquid, at the bottom of the inclined digester 32. Steam 63072 is held at the top of the digester by adjusting and pressure.

When applying the invention to wood, the wood is introduced into the digester 22 in a natural, relatively dry chip or other particle size with an air-liquid medium. The wood chips are passed through an impregnation bath before being transferred to a refiner 10. The pressure limits used in the system are 0.70-10.50 kg / cm depending on the nature of the raw material and the desired end product, preferably 5-25-10. 50 kg / cm. The operating temperature range is 1A0-200 ° C. Under these conditions, the chips are conditioned and impregnated and passed to the refiner 10 cooked. When the chips are impregnated they leave the bath liquid behind. In the grinder, the chips rub against each other and fiberize due to the rotating opposite grinding blades under predetermined pressure and temperature conditions. As the chips pass between the grinding blades, a separation occurs in the longitudinal planes between the fibers. When grinding under such conditions without a liquid medium, fibers are obtained which become elongate between the grinding blades and without noticeable damage.

From the grinder, the fibers enter the top of the scrubber tube 30 for rapid process completion.

Washer 30 is vertical and has a weak washing solution. The scrubber 30 further has an inlet line 33 at the bottom for introducing a weak washing solution and an outlet line 3 at the top for continuously removing the solution from the scrubber. Thus, the washing solution of the fibers passing through it in the tank is kept in the tank 30 by the action of gravity. At the same time, the fibers continue to wash due to the washing solution flowing in the opposite direction. While the fibers leave the scrubber 30, they are effectively released from the unwanted particles attached to them.

The movement of the fibers through the scrubber takes 5-15 minutes depending on the desired cooling or washing effect. The fibers can then be used immediately to make sulfate-type products. It should be noted that the impregnation of the chips in the "M&D" cooker 22 takes 3-40 minutes with the sulphate pulp, while the grinding time is a few seconds.

It must be remembered that the exact time depends on the intended use of the method.

4,63072

In the described continuous system, the final fiber product is obtained in a considerably shorter time than is possible in conventional systems. For high yield pulps, the time consumption in some cases is less than 10 min.

The use of the system of Figure 1 is illustrated by the following examples: A. A mixture of spruce and Douglas spruce chips (54.480 kg as oven dry) is passed through a bath in digester 22, which bath comprises a solution obtained by dissolving e.g. 2.056 kg of sodium sulphide and 6.682 kg of caustic soda in 367.66 liters of water. The pressure maintained in the system should be about 10.50 kg / cm 2 and the temperature about 180 ° C. The controlled transfer of the chips through the digester to the grinder should take place at 14.15 min. The operation of the refiner 10 and the scrubber 30 is described earlier in Figure 3 and the entire operation takes less than 30 minutes. The yield of the resulting pulp is 70% and its Kappa number is 123. The amount of chemical added, expressed as active alkali, is 5.4% Na 2 O. It is clear from this that the process according to the invention gives a high yield of pulp with excellent properties, in a relatively short time and with considerably low equipment and processing costs compared to conventional grinding processes which achieve the same results.

B. The same amount of chip mixture as in Example A can be passed in the same manner through the solution in the digester 22 of the system of Figure 3, which solution has been prepared by dissolving 4.086 kg of Na £ S and 13.347 kg of NaOH.

367.66 liters of water. The transfer time to the refiner is the same as in Example A. Besides, the pressure and temperature of the system are the same. In this case, the mass yield is 60% and the Kappa number is 93.4. The strength properties of the resulting fibers are comparable to the strength properties of fibers obtained from the same chips from ordinary sulfate processes. However, the yield of conventional methods is less than 50%.

Figure 2 shows a modification of the system of Figure 1. The only change in the system is that the vertical scrubber 30 has been replaced by an M & D 2 cooker 22. In this case, the lignin softens under the aforementioned pressure and temperature conditions in the chemical preconditioning before grinding. Otherwise, the procedure is the same in different equipment. for the fibrous material and the required end product, it is necessary to use a more efficient chemical condition of the fibers.However, there is a change in the overall time use in the conditioning process because the raw material passes through the first digester 22 takes 3-40 mins depending on the application. 10.50 kg / cm 2 pressure and temperature 140-200 ° C.

In the system according to Figure 2, in some cases intermediate valves such as valve 41 can be used between the tank 40 and the digester 22 immediately preceding it. This can be done by using special chemicals and for the purpose of transferring fibers through the tank 40 when it is difficult to maintain pressure and temperature conditions therein.

In each embodiment of the invention, controlled and limited conditioning or cooking conditions are used, making it possible to avoid undesired coating of the fibers by easily decomposing the raw material without significantly damaging the fibers. In all cases, a relatively thin fibrous element is obtained which can be used practically immediately for making paper or for other similar purposes. The systems are characterized by speed and minimal power consumption due in part to the elimination of intermediate valves. If it is necessary for some special materials to use valves, these are used either to prevent the gases released from the cooking from entering the previous units of the system or to define an area where different pressures are required. However, it should be emphasized that in the preferred embodiment of the invention, the valves are not used, thus eliminating the operating problems due to the large number of valves.

Claims (10)

63072 6 A method for decomposing and refining a raw fibrous material, for example wood, characterized in that the pieces of raw fibrous material are fed into the pretreatment chamber (22) in contact with the first treatment liquid under sufficient vapor pressure to saturate and boil the fibrous material with the treatment liquid, softening the substance at inter-fiber levels by introducing the fibrous material thus impregnated and cooked substantially free of a liquid other than the liquid contained in the fibrous material into a fiberizing chamber (10) maintained under substantially the same temperature and pressure conditions as the pretreatment chamber; between plate elements rotating in opposite directions, which elements cause torsional and shear forces in the fibrous material to divide it into elongated fibers with a soft coating of lignin or other material in the material, and The coated fibers, substantially free of entrained liquid, are exposed to a second treatment liquid under substantially the same pressure conditions as in the defibering chamber so that the coating of the fibers is modified to provide substantially finished fibers for use in the final product. A method according to claim 1, characterized in that the fibrous material is treated in the pretreatment chamber (22) with a first treatment liquid for 3-10 minutes before the impregnated and cooked material is introduced into the defibering chamber (10), and that the coated fibers are discharged from the space between the rotating plate elements. In 5-60 minutes with a second treatment liquid that converts the fiber coating. A method according to claim 1, characterized in that the fibrous material fed to the pretreatment chamber (22) is continuously passed through the treatment liquid 2 in the pretreatment chamber and the chamber vapor pressure is kept between 0.7 and 10.50 kg / cm, and the fibers are washed after they are fed out of the space between the rotating plate elements and, after their coating has been modified, to release them from the undesired particles attached to them, the treatment being carried out at essentially the same temperature and pressure conditions and without interrupting the flow of fibrous material and fibers obtained. 7 63072 A method according to claim 3, characterized in that the environment through which the fibrous material and fibers are conveyed is maintained at a pressure of about 10.50 kg / cm 2 and a temperature of about 180 ° C, and that the treatment time of the fibrous material in the first treatment liquid it rises to about 10-15 minutes, the time during which the fibrous material is subjected to torsional and shear forces is limited to a few seconds, and the washing time of the obtained fibers rises to n-5-15 minutes. Process according to one of the preceding claims, characterized in that the first treatment liquid is prepared from sodium sulfide, sodium hydroxide and water. Method according to one of the preceding claims, characterized in that the fibers are washed immediately before they are fed out of the pressurized environment in which they are manufactured and their coating is modified. A system for decomposing and refining a raw fibrous material, such as wood, according to any one of the preceding claims, characterized in that the system comprises a digester (22) with an inlet line through which the raw fibrous material can be introduced and comprising a first treatment liquid bath. and a device for receiving and conveying the fibrous material in a continuous flow through the bath, helping to maintain a certain temperature and pressure state of the member (33) connected to the digester (22) in the digester so that the fibrous material is impregnated and cooked through the bath during transport, the fibrous chamber (10) and the member for introducing cooked fibrous material from the digester into the defibering chamber in a state substantially free of a liquid other than that contained in the fibrous material per se, the defibering chamber (10) having plate elements centrally spaced relative to each other to rotate relative to each other torsional and shear forces of the fibrous material to distribute the fibrous material into elongate fibers along longitudinal planes between the fibrous material fibers, thereby contributing to maintaining the defibering chamber and the entire apparatus at the same temperature and pressure mechanical disintegration before passing between the elongate fibers rotating relative to each other and the elongate fibers obtained therefrom have a coating consisting of materials softened between the fibers of the fibrous material, impregnated, cooked and distributed in the distribution, partly further in a container (30, 22 '), a bath of treatment liquid into which the fibers are introduced from the defibering chamber (10), the second container being shaped so that the coated fibers are transported through the bath and fed out in a modified state, mainly ready for use in the final product. A system according to claim 7, characterized in that the second container (30, 22 ') is connected to a member (33, 34; 40) for washing the fibers before they are fed out in a conditioned state. A system according to claim 7, characterized in that the second tank is a digester (22f) with the same pressure space as in the defibering chamber, so that the passing fibers are not only converted but also subjected to the second cooking. System according to one of Claims 7 to 9, characterized in that the second tank is provided with means for washing (44) the fibers first and then for conditioning and finally for cooling (45) before they are discharged from a pressurized environment maintained in a digester, a defibering chamber and a second in the tank.