Method for continuous production of pulp chemical pulp digester continuous action

 

(57) Abstract:

Group of inventions relates to the continuous production of pulp chemical pulp and industrial cooking comminuted cellulosic fibrous material. Method for continuous production of pulp chemical pulp is carried out at the transmission in the direction of node sieve and a liquid suspension of the crushed pulp fiber material with the concentration of dissolved organic material (RUM), essential for the adverse influence on the main technical characteristics of cellulose, diverting part of the water with the concentration of RUM from the suspension of the node sieves, recycling part of the reserved liquid back into the digester to the node sieves and the introduction of cooking liquor in the recirculation circuit. At this dilution liquor with a low concentration of RUM injected into the recirculation loop, and recycling in the digester is carried out at low concentrations of RUM, which is different from the concentration of RUM in introduced into the recirculation loop dilution liquor. In the digester continuous action in addition to discharge and recirculation pipelines are connected to atmodas is improving the efficiency of the cooking process and the strength of sulphate pulp. 2 C. and 20 C.p. f-crystals, 2 tab., 25 Il.

The invention relates to a method for continuous production of pulp chemical pulp and cooking boiler continuous action.

There is a method for continuous production of pulp chemical pulp using at least one node sieves in a digester, comprising passing a liquid suspension of the crushed pulp fiber material in the first direction to the node SITA and his suspension has a first level of dissolved organic material; allocating a portion of the fluid having the first level of dissolved organic material from the slurry in node sieve;

C) recycling at least some portion of the liquid reserved in the previous step in the recirculation loop back to the digester in approximately the position of the node sieves, the introduction of cooking liquor in the recirculation loop (EP 0476230 D 21 C 3/02).

According to the conventional information in the field of sulphate pulping, it is known that the level of dissolved organic material (RUM), which mainly include the dissolved hemicellulose and lignin, but also include dissolved pulp, extracts and other m is sa cooking, preventing delignification due to the consumption of active chemical cooking substances in solution before they can react with residual or natural lignin in the wood. The effect of the concentration of RUM at other stages of the cooking process, in addition to subsequent stages, according to the relevant information is assumed to be insignificant. Preventing the influence of RUM at the subsequent stages of cooking is minimized in some known continuous cooking processes, in particular using digester "EMCC(R)" firm "Kamyr, Inc." (Kamir. Inc."). Glens falls, new York, since the reverse flow of liquor (including white (fresh) lye) at the end of cooking reduces the concentration of RUM in the late phase of bulk delignification", and during all phases of the so-called "residual delignification".

In accordance with the present invention discovered that RUM not only have a negative impact on the boil at the end of the cooking phase, but their presence has a negative effect on the technical strength of the pulp at any stage of the cooking process, i.e., early, middle and late stages of bulk delignification. The mechanism by which RUM have a negative impact on the strength of technicaldata mass allocated using alkalis organic substances through the walls of the fibers, due to the presence of dissolved organic materials (RUM) surrounding the fiber and various extractibility available in the fibers of crystalline regions (i.e., nodes) in comparison with amorphous regions. In any case, in accordance with the invention, it has been demonstrated that if the level (concentration) RUM is minimized during cooking, the technical strength of the pulp is increased substantially. In accordance with the present invention found that if the RUM is close to zero throughout sulfate pulping cellulose, the technical strength of the pulp increases significantly, i.e. an increase of approximately 25% (for example, 27%) tensile 12 km, compared with the sulphate cellulose obtained in the usual way. Even reduce RUM to half or a quarter of their normal levels also significantly increase the technical strength of the pulp.

In known methods of sulfate pulping concentration of RUM in some moments sulfate pulping useful to maintain a level of 130 g/l or more, and at the level of 100 g/l or more in numerous moments sulphate cooking (for example, when the bottom circulation, circulation in the purification and circumcision, wench."), even if the level of RUM supported in the range of approximately 30-90 g/l at flushing circulation (at the subsequent stages, in accordance with the existing traditional experience). In such conventional situations is also useful to have the lignin component level RUM over 60 g/l, and in fact even more than 100 g/l and hemicellulose component level RUM is better to have a value of more than 20 g/L. it is Unknown whether the component dissolved hemicelluloses stronger negative impact on the technical strength of pulp (for example - because of the negative influence on the mass transfer of organic substances from the fibers) than lignin, or Vice versa, or whether it is a synergistic effect, although it can be expected that the dissolved hemicellulose has a significant impact.

In accordance with the present invention revealed, first, that the concentration of RUM throughout sulfate pulping should be minimized, to positively influence belmost technical cellulose, reduce chemical consumption and significantly increase the strength of technical cellulose. Minimizing levels of RUM, you can create the digesters continuous smaller, odnovremenno systems with periodic tasks (batch systems). A large number of these useful results you can anticipate maintaining the concentration of RUM at the level of 100 g/l or less for essentially all of the sulfate pulping (i.e., at the beginning, in the middle and at the end of the bulk delignification), preferably at about 50 g/l or less (closer to zero concentration of RUM, the better the results). In particular, it is desirable to maintain the lignin component at 50 g/l or less (preferably 25 g/l or less), and the level of hemicellulose - 15 g/l or less, preferably about 10 g/l or less). In accordance with the present invention also discovered that you can asseverate negative effect of the concentration of RUM on the technical strength of the pulp, at least to a significant extent. According to this aspect of the invention found that if the black liquor is removed and subjected to heat treatment under pressure in accordance with U.S. patent N 4929307 (the mention of which is shown here for reference), for example at a temperature of about 170-350oC (preferably 240oC for about 5-90 minutes (preferably about 30 to 60 minutes), and then re-enter, you can cause an increase in tensile strength up to about 15%. The mechanism asanoi hypothesis and the results of its impact real and effective impact on the technical strength of the pulp. In accordance with the present invention has developed various ways to increase the strength of sulphate pulp, considering the negative influence of RUM, as described above, and systems continuous and periodic actions. In addition, in accordance with the present invention developed technical cellulose increased strength, as well as a device to achieve the desired results according to the present invention. In addition, in accordance with the present invention can significantly reduce the H-factor, for example, lower H-factor of at least about 5%, in order to achieve a given Kappa number. You can also significantly reduce the effective amount of alkali, for example, at least about 0.5% on wood (e.g. about 4%), to obtain a specific number of Kappa. And you can still achieve high belibaste, for example - increasing the degree of whiteness according to the scale MOC/ISO), at least one unit in a particular Kappa number, to complete the sequence.

According to one aspect of the present invention, a method of obtaining cellulose by boiling the crushed pulp fiber is whatney cooking material with the purpose of obtaining technical cellulose: (a) extraction liquor, contains the level of RUM, significant enough to have a negative impact on the technical strength of the pulp. And (b) replacement of part or all of the extracted liquor liquor containing significantly lower effective RUM than the extracted liquor, in order to have a positive impact on the technical strength of the pulp. The operation (b) is usually carried out by replacing the exhaust liquor liquor selected from the group consisting essentially of water, white liquor, is essentially not containing RUM, subjected to heat treatment under pressure of the black liquor, the wash filtrate, filtrate cold blowing, and combinations thereof. For example, at least one node in the process of cooking, you can take black liquor and process it in some conditions of pressure and temperature (for example, at a pressure above atmospheric and a temperature of about 170-350oC for about 5-90 minutes and the temperature, at least on the 20oC above the temperature of boiling) to significantly Passepartout negative impact RUM. The term "effective POM" in the sense it is used in the description and the claims, means that part RUM, which has a negative impact on p is active ROM can be obtained by passivation (except impact on belibaste) or by applying an initially low concentration of RUM.

The proposed method can be implemented in a vertical digester continuous actions and operations (a) and (b) can be done in at least two different levels of the digester. Typical is also the additional operation (C) heating the replacement liquor from operations (b) essentially to the same temperature as the temperature of the exhaust liquor, prior to the introduction of the replacement of the liquor in contact with the material, which is brewed. Operations (a) and (b) can be done during impregnation, at the beginning of cooking, in the middle of cooking and at the end of cooking, i.e., essentially during all stages of bulk delignification.

According to another aspect of the present invention, a method of sulphate pulping, which includes operations in the beginning of the sulfate cooking: (a) extraction liquor containing the level of RUM, significant enough to have a negative impact on the technical strength of the pulp. And (b) replacement of part or all of the extracted liquor liquor containing significantly lower effective RUM than liquor extracted, in order to have a positive impact on the technical strength of the pulp.

According to another aspect of the present sobrescrito material: (a) extraction liquor, contains the level of RUM, substantial enough to have a negative impact on the technical strength of the pulp. And (b) replacement of part or all of the extracted liquor liquor containing significantly lower effective RUM than the extracted liquor, in order to have a positive impact on the technical strength of the pulp.

According to another aspect of the present invention, a method of sulphate pulping, including the following: (a) extracting black liquor contacted technical cellulose at a particular stage of cooking, (b) heating under pressure of the black liquor to a temperature sufficient to significantly passivate a negative impact on technical cellulose contained RUM, and (C) re-enter the black liquor with fried RUM in contact with the technical cellulose at a particular stage of cooking.

The invention also includes sulphate technical cellulose obtained by the methods mentioned above. This sulphate technical cellulose differs from that produced first varieties of technical cellulose sulfate having a tensile strength at 25% larger when C is greater at least 15% more) compared to sulphate technical cellulose, obtained in identical conditions, without maintaining a certain level of RUM or proposed operations of-way, or 15% more (e.g. at least about 10% more) when using passivated black liquor.

The invention is also applicable to periodic sulphate cooking cellulosic fibrous material using a tank containing black liquor, and digester periodic action containing material. In this proposed method, periodic sulfate pulping operations are: (a) heating under pressure of the black liquor in the tank to a temperature sufficient to asseverate negative impact on the technical strength of the pulp from the contained RUM. And (b) supply of black liquor in the digester in order to bring it into contact with the boiler cellulosic fibrous material. The operation (s) carried out for the purpose of heating the black liquor at a pressure above atmospheric at a temperature of about 170-350oC for about 5-90 minutes (usually at a temperature of at least about 190oC for about 30-60 minutes, the temperature is approximately at least 20oC higher temperature is arched boiler for holding cooking cellulosic fibrous material.

According to another aspect of the present invention, a device has been developed for sulfate pulping pulp. The unit contains the following elements. Vertical digester continuous action. At least two extracting the outlet of the sieve provided at different levels and different cooking boiler units. Each sieve is connected to the recirculation piping and pipeline extraction. In addition, for each of the pipelines recirculation means are provided to supply replacement liquor in the recirculation pipe for replenishing liquor extracted in the pipeline extraction. Each recirculation circuit typically includes a heater, and the digester can be connected with a separate impregnation vessel, which is diverted liquor with a high concentration of RUM and its replacement by a liquor with a low concentration of RUM (including the return line that runs between the top of the impregnation vessel and the high pressure feeder).

The invention also relates to industrial way sulphate cooking comminuted cellulosic fibrous material by carrying out the operation (a) continuous transmission, essentially not containing RUM cooking cooking material, ensuring speed transmission, at least 100 tons of industrial pulp per day. This method is preferably carried out using digester periodic operation, with a capacity of at least 8 tons per day (for example 8-20 tons per day), and additional operations (b), before surgery (a), filling the digester pulp material and additional operations (b) after operation (a), production of sulphate pulp from the digester. The invention also relates to a system digesters periodic actions for implementation in practice of this aspect of the invention, each digester periodic operation has a capacity of at least 8 tons per day (i.e., has a capacity of industrial - scale compared with the performance of the laboratory scale).

The invention also relates to the modification of a number of different types of digesters continuous, conventional digesters MCC(R)" firm "Kamyr, Inc." or digesters "EMCC(R)" firm "Kamyr, Inc., in order to achieve significant dilution effective RUM cooking liquor, at least one primary cooking node or intermediate cooking site. Due to the selected conkie with the invention in existing digesters, simply by reallocating the different flows of fluid and the introduction of dilution liquor with low content of RUM and/or white liquor at various points in all conventional types of digesters continuous action, including odniesienie hydraulic, hydraulic tank, etc.

The main technical problem of the invention is to provide cellulose increased strength and/or decrease the H-factor and the consumption of alkali and improving belibaste. These and other technical challenges of the invention will become apparent from a consideration of the detailed description of the invention and from the accompanying claims.

Fig. 1 is a schematic representation of an exemplary variant embodiment of the proposed equipment continuous sulfate cooking for implementation of the proposed approximate methods;

Fig. 2 and 3 graphically technical strength of the cellulose obtained in accordance with the present invention, compared with the sulphate cellulose obtained in identical conditions, but without the embodiment of the invention;

Fig. 4 is a schematic illustration of an exemplary equipment for the proposed improvements of the method periodic sulfate pulping;

Fig. 5 is a schematic side view of another variant embodiment of the proposed approximate digester periodic action;

Fig. 6 - graphic depicts what lolotoi, obtained in identical conditions, but without the embodiment of the invention;

Fig. 7 is a graphical depiction of consumption of effective alkali in obtaining technical cellulose in accordance with the present invention, in comparison with obtaining technical cellulose in identical conditions, but without the embodiment of the invention;

Fig. 8 is a graphical representation of dependence consumed effective alkali percentage milled liquor compared with lye, not containing RUM;

Fig. 9 is a graphical image in which a comparison of the reaction degree of whiteness for various technical cellulose obtained in accordance with the present invention, and sulfate cellulose, obtained in identical conditions, but without the embodiment of the invention;

Fig. 10-14B - additional graphic images of various aspects of the technical strength of the cellulose obtained in accordance with the present invention, and

Fig. 12A-B show a comparison with sulfate cellulose obtained in identical conditions, but without the embodiment of the invention;

Fig. 15 is a graphical depiction of the concentration of RUM, derived from the analysis of real liquor laboratory is 16 - a schematic representation of an exemplary digester twin hydraulic digester system embodying the present invention;

Fig. 17 is a graphical depiction of theoretical studies, which compared the concentration of RUM in a conventional digester MCC(R)" and in the digester shown in Fig. 16;

Fig. 18-20 - schematic diagram of two exemplary digesters of the present invention, and Fig. 21-25 - graphics theoretical studies of changes of parameters of dilution and extraction using digester shown in Fig. 19.

In Fig. 1 shows dupreziana hydraulic system sulfate cooking, such as supplied by the company "Kamyr, Inc., Glens falls, NY, modified to an exemplary embodiment of the methods of the present invention. Of course, for embodiments of the invention can be modified and other existing systems digesters continuous action, including odniesienie hydraulic, odniesienie vapor and dupreziana vapor digesters.

In an exemplary variant of the embodiment shown in Fig. 1, a conventional the military cellulosic fibrous material, flowing water, and the cooking liquor is supplied from a conventional high pressure feeder pipeline 12 to the top of the tank IV 10, and some liquor divert the pipe 13, as usual, and return in the high-pressure feeder. In accordance with the present invention, in order to reduce the concentration of RUM (in the sense given to this term in this description and the claims, dissolved organic materials, primarily dissolved hemicelluloses and lignin, but also dissolved pulp, extracts and other materials extracted from wood during sulphate pulping), liquor divert by a pump 14 into the pipe 15 (or from the top of the tank 10 and is processed at the node 16 to remove or passivation RUM or their individual components. Node 16 may be the site of deposition (e.g. by reducing the pH to a value of less than 9), the site of absorption (e.g. column with cellulose fiber or activated carbon), or a device to filter (for example, ultrafiltration, microfiltration, nanofiltration, and so on), extraction solvent, decomposition (for example - bomb radiation), extraction in Natchitoches condition, g is, after node 16), you can optionally submit or not to submit to the pipe 13 by pump 14' in the pipeline 17, depending on, carry out the impregnation in a parallel flow or counterflow. Replacement liquor, additionally submitted into the pipeline 17 instead of the extracted liquor, processed in the node 16 may be a dilution liquor, for example, fresh (i.e. essentially not containing RUM) white liquor, water, wash the filtrate (for example, the filtrate flushing drilling wood (brownstock)), the filtrate cold blowing, or combinations thereof. If you want to increase sulfinate liquor circulating in the pipes 12, 13, it is possible to additionally apply to the pipeline 17 black liquor, but it should be treated so as to provide passivation contained RUM, as will be described below.

In any case, lye, designated by a pipe 15 has a relatively high concentration of RUM, while the liquor, and additionally submitted into the pipeline 17, has a much lower effective RUM, to positively influence the technical strength of the pulp.

In the impregnating tank level 10 RUM also control - preferably using a conventional sieve 18, nasaac shown through pipeline 21 - dilution fluid to reduce the concentration of RUM. This dilution liquid also comprises at least a little bit of white liquor. It is liquor, re-introduced into the pipeline 20, will have a significantly lower level of effective RUM than liquor allocated through a sieve 18, and will include, at least, a little white liquor. The processing unit 16', similar to the node 16 may also be provided in the pipe 20, as shown by a dotted line in Fig. 1.

From the bottom of the tank IV 10 suspension of comminuted cellulosic fibrous material is passed by line 22 to the top of the digester 11, and, as you know, part of the liquid suspension divert on line 23, add to it the white liquor through the pipe 24 and is passed through a heater (usually the heater with indirect heating) 25, and then re-injected at the bottom of the tank IV 10 through the pipeline 26 and/or administered at the beginning of line 22, as shown through pipe 27 in Fig. 1.

In existing digesters, continuous action normally liquid assign different levels of the digester, heat up, and then re-enter on the same level, where averted, however, in normal working conditions is atlah continuous black liquor is extracted in the Central part of the boiler and not re-enter, but rather throw in the pits, and then, eventually, pass in a boiler or similar unit. In contrast to the existing digester continuous action, the proposed digester 11 continuous action actually extract liquor on a number of regular nodes and heights and replaces the extracted liquor liquor having a lower design RUM. This is done at the beginning of cooking, in the middle of cooking and at the end of cooking. Through the use of digester 11, shown in Fig. 11, and the practical implementation of the proposed method, technical cellulose, manufactured by pipeline 28, has a higher tensile strength compared to conventional sulfate cellulose treated differently in identical conditions in an existing digester.

The digester 11 includes a first set of outlet 30 sit at the top of the boiler, at the beginning of cooking, the second set of sit 31 in the middle of cooking, and the third and fourth sets screens 32, 33 at the end of cooking. Sieve 30-33 are connected to pumps 34-37, respectively, through which are passed the recirculation piping 38-41, respectively, do not necessarily include heaters 42-45, respectively, and these contours recirculation with reginout in pipelines 46-49, accordingly, due to the transmission pipeline, such as 46, to a series of sumps 50, as shown in connection with the first set of sieves 30 in Fig. 1.

To replenish the extracted liquor, which has a relatively high concentration of RUM, and to reduce the level of RUM, additionally serves substituting (dilution) lye, as shown by pipeline 51-54, respectively, and liquor additionally supplied through pipelines 51-54, has a much lower concentration effective RUM than liquor extracted in pipelines 46-49, in order to have a positive impact on the technical strength of the pulp. Liquor, additionally filed in pipelines 51-54 may be the same as diluting liquors listed above in connection with the pipe 17. Heaters 42-45 heated replacement liquor, and any recycled liquor, essentially to the same temperature as the exhaust liquor (usually up to a slightly higher temperature). In the digester 11 can include any number of sieves 30-33.

Before you move the extracted liquor to a remote place and replacing it with the replacement liquor extracted liquor and replacement liquor can flow in heat what edstam position 56 in Fig. 1. Further, the extracted liquor can be processed to remove or passivation contained RUM, and then immediately re-enter as a substitute liquor (if necessary with another, dilution liquor added to it). This is schematically shown by position 57 in Fig. 1, which shows that the extracted liquor received by pipeline 48 is processed at station 57 (similar to node 16) in order to reduce the level of RUM, and then re-enter the pipeline 53. It also added white liquor, as shown in Fig. 1, you can actually add the white liquor at each of the nodes associated with the Sith 30-33 in Fig. 1 (pipeline 51-54, respectively).

Another option for processing unit 57, shown schematically in Fig. 1 is the heating of black liquor under pressure. From the sieves 32 assign lye, which can be regarded as "black liquor", and part of it is extracted by pipeline 48. Heating under pressure at node 57 can be made in accordance with U.S. patent N 4929307, the mention of which is given here for reference. Usually in the node 57 black liquor should be heated to a temperature in the range of about 170-350oC (preferably above 190ooC higher than the temperature of boiling. This leads to a significant passivation of RUM, and then you can return the black liquor back, as shown through pipe 53. The processing unit, schematically position 58 in Fig. 1, associated with the last set of branches/extracting Sith 33, similar to the node 16. Node, like node 58 can be provided or not be provided at any level of the digester 11, where the extraction instead of additional feed dilution liquor. You can also optionally apply to the node 58 white liquor, and then return liquor with reduced levels RUM pipeline 54.

Regardless, use of the processed extracted liquor or dilution liquor, in accordance with the invention, it is desirable to maintain the total concentration of RUM cooking liquor at the level of 100 g/l or less for essentially all of the sulfate cooking (bulk delignification), preferably less than about 50 g/l, as well as to maintain the concentration of lignin at 50 g/l or less (preferably about 25 g/l or less), and the concentration of hemicellulose - at the level of 15 g/l or less (to take different values, depending on the species of wood being cooked.

In Fig. 2 and 3 shows the results of laboratory tests related to the present invention. In Fig. 2 shows curves "gap-wear" for three different laboratory sulphate boiling cycles, and they all received on the same part of the wood pulp. The coefficient of rupture is a measure of the strength inherent in the original fibers and technical cellulose.

In Fig. 2 curve A corresponds to the technical cellulose, obtained using standard bulk cooking ground liquor (taken from full-scale industrial products of the cooking process in the cooking pot MCCR"as the cooking liquor. Curve B obtained as a result of cooking, in which the cooking liquor was the same as in the case of curve A, except that the liquor samples were heated at a temperature of about 190oC for one hour at a pressure above atmospheric before you can use it when cooking. Curve C shows the cooking, which used a synthetic white liquor as the cooking liquor, and this synthetic white liquor is not essentially contained RUM (i.e., their concentration was less than 50 the I temperature of about 160oC) profiles and concentrations of RUM were identical to the corresponding parameters of the full-scale cooking process, from materials which samples were taken liquor. For the curve C profiles of consumption of alkali and temperature were identical to those of curves A and B, but RUM was absent.

In Fig. 2 clearly demonstrated that the low level of RUM in liquor, come into contact with the chips during the entire sulphate cooking, there is approximately a 27% increase in tensile strength tensile (11 km Passivation RUM by heating under pressure black liquor, corresponding to curve B, according to the invention also leads to a significant increase in strength as compared with A standard curve, in this case to increase the tensile strength by approximately 15% tensile 11 km.

In Fig. 3 shows another laboratory work compared to conventional sulfate boiling cycles with boiling in accordance with the invention. Cooking, displayed curves D-G, were obtained under identical profiles of consumption of alkali and temperature for the same wood, but when changing concentrations of RUM for the whole sulphate cooking. The concentration of RUM for curve D representing a hundred who ncentrate RUM for the curve G (essentially - in the absence of RUM) was the lowest. The concentration curve E was approximately 25% lower than the design RUM for curve D, whereas the concentration of RUM for the curve F was approximately 50% lower than the concentration of RUM for curve D. As you can see, there was a significant increase in the tensile strength, in all cases proportional to the amount of RUM that are present throughout cooking.

Cooking in accordance with the invention is preferably carried out in practice in order to achieve increased strength technical cellulose (e.g. tensile strength at a given elongation to fully purified technical cellulose, for example - while stretching 9 miles or 11 km) of at least about 10%, and preferably at least about 15% compared with terms identical in all other respects, but without special maintenance of the level of RUM.

Although with reference to Fig. 1 the invention has been disclosed with respect to continuous sulfate cooking of cellulose, the principles relevant to the invention are also applicable to periodic sulphate cooking pulp.

In Fig. 4 schematically depicts a typical equipment that can be used in the implementation in practice periesophageal in Fig. 4, includes the digester 60 periodic action, having a drain sieve 61, the source 62 of the chip, the first, second and third drives 63, 64, 65, respectively, the source 66 of white liquor tank 67 to the filtrate, the purge tank 68, and a number of valve mechanisms, the first of which is schematically shown a 69 position. In the usual model workflow process "Beloit. RDHTM" the digester 60 fills the chips from the source 62 and, if necessary, treated with steam. Then in the digester 60 served warm black liquor. Warm black liquor typically has high sulfinate and low alkalinity and a temperature of about 110-125oC and comes from one of the drives (e.g. from a memory 63).

Any excess amount of warm black liquor can be skipped in the tank liquor and ultimately to submit to the evaporators, and then skip to chemical regeneration. After impregnation warm black liquor in the digester 60 return in the memory 63, after which the digester 60 fill hot black and white liquor. Hot black liquor can be served from memory 65, and the hot white liquor from the accumulator 64, and ultimately from a source 66. Usually white liquor and is then chips in a digester 60 cook during a specified period of time at a temperature, sufficient to obtain the desired H-factor, and then hot lye mix together with the filtrate directly into the memory 65, and the filtrate from the reservoir 67. The chips are subjected to cold blowing compressed air or pumped from a boiler 60 in the purge tank 68.

During the typical process RDHTM" white liquor is continuously heated liquor from the drive 65 in such a way as to provide significant passivation RUM in the composition of the liquor. For example, this can be achieved by heating the black liquor to a temperature of at least 170oC for about 5-90 minutes, and preferably at 190oC or higher (for example - 240oC) for about 5-90 minutes In Fig. 4 this additional heating is schematically displayed position 71, the heat can be obtained from any desired source. This heating under pressure black liquor receive exhaust gases rich in organic sulfur compounds, and to divert them, as shown by position 72. Usually, which is in itself known, DMS (dimethyl sulfide) obtained in the pipe 72, and is converted into methane and hydrogen sulfide, and methane can be used as fuel additives (for example, to provide nanika 72 to cooking, can be converted to elemental sulfur and to take or use it to form the polysulfide is possible to achieve absorption of white liquor to obtain liquor high sulfides and so on, If the heat treatment in the drive 65 is carried out at a temperature of about 20-40oC above the temperature of cooking, you can use black liquor to facilitate impregnation during sulphate pulping.

Instead, in accordance with the invention in the variant depicted in Fig. 4, the valve mechanism 69 can be associated with a processing node such as node 16, shown in Fig. 1, to extract the ROM from the cooking liquor, which lead away from the screens 61 and recycle in the digester 60 during periodic cooking.

In Fig. 5 schematically depicts exemplary (industrial, i.e. producing at least 8-20 t technical pulp per day) system 74 periodic sulphate cooking, corresponding to the present invention. Laboratory version shown in solid line in Fig. 5 a variant embodiment of the system 74 used to obtain the graph C shown in Fig. 2, and this version has been in use for many years. System 74 includes digester 75 periodic is 80 lb chip, mounted in the pot during cooking. On one level inside the boiler is provided by the sieve 81 (for example - at the bottom 77) connected to the exhaust tube 82 and the pump 83, and these communications lead to the heater 84. From the heater 84 of the heated liquid recycle pipeline 85 back into the digester 75, injecting it into the boiler at a level different from the level of the sieve 81 (for example - at the top 76).

Before the heater 84 significant portion (for example, to provide approximately three turns of fluid per hour) exhaust pipeline 82 lignin extracted in the pipe 86. This liquor with a relatively high concentration of RUM replace coming through the pipeline 87 liquor, essentially not containing RUM (at least at a significantly reduced concentration of RUM in comparison with that which takes place in the pipe 86). Additionally supplied through the pipe 87 liquor, essentially not containing RUM, can have a concentration of alkali, which vary in order to ensure proper sulphate cooking. For modeling continuous sulfate cooking pot 75 periodic action you can use the changing concentration of alkali. It is possible to provide valves 88, 89 to interrupt or INERGEN dashed line in Fig. 5. In accordance with the invention, instead of or in addition to the construction of pipelines extraction and dilution 86, 87 can be provided to achieve the desired level of RUM and their components (for example, less than 50 g/l RUM, less than 25 g/l lignin and less than 10 g/l hemicellulose) by processing the extracted liquor to reduce RUM, for example, by passing the liquor with a high level of RUM on the pipe 90 to the processing unit 91, similar to the node 16, shown in Fig. 1, in which RUM or selected components removed to a significant reduction in their concentrations in the leachate. You can also optionally serve to replenish white liquor (not shown), liquor, heated in the heater 92, and then return it to the pipe 93 to the digester 75 instead of using pipes 90 and 93, and to the processing unit 91 can be connected to the pipes 86, 87, as shown schematically by dashed lines 95, 96 in Fig. 5.

Data from other laboratory tests that illustrate the benefits that can be achieved in accordance with the present invention, shown in Fig. 6-15. Upon receipt of data from these laboratory tests were used procedures that simulate the digester nepreryvnog amount of wood shavings. The various nodes of the digester continuous simulated by altering the time, temperature and chemical concentrations used in the circulation. In these models used real liquor, came to the modulation of the corresponding node digester continuous action in the laboratory of cooking.

Impact minimization RUM in the cooking liquors on the required conditions of cooking (i.e., time and temperature) is illustrated in Fig. 6. In Fig. 6 comparison of interchangeability between the Kappa number and the H-factor for laboratory boiling cycles using ground black liquor and essentially not containing RUM white liquor. Wood prepared for boiling cycles shown in Fig. 6, was a common soft wood from the North-West of the USA, consisting of a mixture of cedar, spruce, pine and fir. H-factor is a standard parameter that characterizes the cooking time and the cooking temperature as a single variable and are described, for example, in "Pydholm Pulping Processes", 1965, S. 618.

Line 98 in Fig. 6 shows the relationship between Kappa number and the H-factor for laboratory cooking using ground liquor (collected at the mill, and then used in the lab cooking coarse using the obtained in the laboratory white liquor, essentially not containing RUM. Lines 98, 99 show that for a given Kappa number H-factor is significantly lower when lower RUM, for example, for a value of 30 Kappa number in Fig. 6 the difference between the values of H-factor of approximately 100. This means that for the same wood with the same chemical loading, if used cooking liquor with a lower level of RUM, then you want less severe boiling (i.e., with less time and a lower temperature) than the normal sulphate cooking. For example, extragere liquor containing the level of RUM, significant enough to have an adverse effect on the H-factor and replacing part or all of the extracted liquor liquor containing significantly lower effective RUM than the extracted liquor, can significantly reduce the magnitude of the H-factor, preferably, in practice, take measures aimed at reducing the values of the H-factor of at least about 5%, to obtain a given Kappa number, and take action, focus on maintaining a concentration effective RUM at the level of about 50 g/l or less during the greater part of the sulphate process cooking.

As shown in Fig. 7, when ilenia effective alkali (AS). AS is a measure of the amount of cooking chemicals, in particular NaOH and Na2S used when cooking. The results, shown in Fig. 7, were obtained using the same composition of wood, as in Fig. 6 and both line graphs 100, 101 obtained in the same conditions. Line 100 shows the results for the case when the cooking liquor was a common ground lye, whereas line 101 shows the results for the case when the cooking liquor was a white liquor, is essentially not containing RUM. When the Kappa number is 30, in the case of cooking with the use of liquor, essentially not containing RUM, alkali consumption was approximately 30% less (i.e., AS on wood 5% less) than conventional cooking using ground liquor. Thus, extragere liquor containing the level of RUM significant enough to be a negative influence on consumption of effective alkali, in order to achieve a specific Kappa number, and replacing part or all of the extracted liquor liquor containing significantly lower effective RUM, you can significantly reduce the amount of effective alkali consumed to achieve a particular number is (for example, approximately 4% on wood) to achieve specific Kappa number.

Useful results in part of the H-factor and consumption AS, illustrated in Fig. 6 and 7, can be achieved by replacing the extracted liquor with relatively high levels of RUM, water, white liquor, is essentially not containing RUM, black liquor is subjected to heat treatment under pressure, the filtrate or their combinations.

In Fig. 8 shows another graphical representation of the consumption of effective alkali, depending on the percentage of ground liquor in comparison with the same dependence on the percentage of white liquor, is essentially not containing RUM. Graph 101 shows that for the same relative number Kappa consumption of effective alkali decreases the percentage of ground liquor (i.e., increase the percentage of white liquor, is essentially not containing POM). At the end of the text table. 1 shows the real results of laboratory tests that were used to plot 101, shown in Fig. 8.

Low concentrations or exclusion RUM contained in the cooking liquor, also the s actual results of laboratory tests, showing how the degree of whiteness of the bleached technical cellulose, obtained from a mixture of cedar, spruce, pine and fir increases with increasing dose of bleaching chemicals. The parameter plotted on the X-axis of the graph shown in Fig. 8 - "Kappa factor full

sequence is the ratio of the equivalent dose of chlorine to the input value of the Kappa number of technical cellulose. That is, it is somehow standardized number used chlorine to the original lignin in the technical pulp and softwood. Thus, Fig. 9 shows the dependence of the degree of technical white pulp from the amount of used chemicals.

Curves 102, 103, 104 and 105 shown in Fig. 9, refer, respectively, to the white liquor, is essentially not containing RUM (102), normal molotow the liquor (103), cooked with grinding technical cellulose (not for laboratory technical cellulose obtained by the use of ground liquor) (104), and to termoobrabotannom when grinding the black liquor, which was subjected to heating (105). These graphical representations clearly show that the best belmost is achieved when, as in the level of RUM, substantial enough to adversely affect belmost technical cellulose, and replacing the part or volume of the extracted liquor liquor containing significantly lower effective RUM, can greatly improve belmost get technical cellulose, for example, at least one brightness of the ice (ISO) at a particular value of the Kappa factor of the full sequence. Instead, we can also assume that the specific degree of whiteness on the ice can be achieved using a reduced loading of bleaching chemicals. However, graph - line (105) shows that although heat-treated black liquor can improve the delignification (see Fig. 2), it can be difficult to remove the residual lignin. Thus, it may be desirable to use the treated black liquor as dilution liquor when you want to achieve high belibaste, and in this case, preferably water, white liquor, is essentially not containing RUM and the filtrate (and their combinations) as dilution liquor. However, in the case of cellulose, which is not bleached, i.e., in the case of unbleached technical grades of pulp, you can use the who shows the most significant impact on the technical strength of the pulp. This is further supported by data presented in graphical form in Fig. 10-14B. All these data were obtained for wood, including cedar, spruce, pine and fir, i.e., the same of which was discussed with reference to Fig. 6-9, and these data show that under the same conditions of cooking tensile strength increases significantly with the decrease RUM. For example, in Fig. 10 shows that the tensile strength tensile 11 km increases (see line 106) with a decrease in the number of ground liquor (and, thus, increase the amount of white liquor, is essentially not containing RUM) for the illustrated laboratory boiling cycles. In Fig. 11 shows the same basic dependence through graph 107, which shows the dependence of the gap at 600 units of the PSC (CSF - Canadian Standard Freeness - canadian standard mobility) from the percentage of ground lye.

Here at the end of the text table. 2 illustrates the values of tensile strength at two tensile stresses for laboratory boiling cycles carried out with various liquors, together with shows comparison data gap for technical pulp obtained by grinding. Are given in table. 2 data boiling 2 and 3 pokazannoi using white liquor, essentially not containing RUM, compared with the laboratory of cooking, which used ground lye, dvenadtsatiperstnoi (12%) increase for tensile strength tensile (11 km Data laboratory boiling 4, 5 and 6, are given in table. 2 show the result of the replacement of liquor, not containing RUM, in specified parts of cooking, the respective ground liquor. For example, in the 4 cooking liquor from pipe bottom circulation (NC) was replaced prepared in the laboratory liquor in the node SU lab cooking. Similarly, in varca 5 aircraft and modified cooking (MB), used powdered lye in the lab cooking in the nodes NC and MB, while the other nodes used liquor, essentially not containing RUM. The data in the table. 2 show that the minimization of RUM important throughout the cooking, and not just in the final stages and it is fully confirmed by the analysis carried out above in relation to Fig. 2 and 3.

In Fig. 12A - 14B illustrate the influence of RUM on the strength of bleached technical cellulose. In Fig. 12A shows the dependence of tensile strength on stretching for unbleached technical cellulose, and line 108 displays characteristics of cellulose, obtained by applying laboratwere heat treatment under pressure, and the line 110 shows the results of applying the ordinary ground of liquor. In Fig. 12B shows the dependence of tensile strength on stretching for various technical cellulose, shown in Fig. 12A, after they have been bleached using laboratory bleaching sequence DE0D(nD). Line III shows the characteristics of the bleached technical cellulose obtained by the use of white liquor, is essentially not containing RUM, subjected to heat treatment under pressure, the line 112 shows the technical characteristics of the pulp obtained by the use of ground liquor subjected to heat treatment under pressure, and line 113 displays the characteristics of bleached technical cellulose obtained by the use of conventional ground liquor, while, for comparison, line 114 displays the strength of ground technical cellulose obtained from PAP machine, after bleaching. Fig. 12B shows that stronger technical cellulose obtained by the use of ground liquor, only technical cellulose, welded essentially in the absence of RUM in liquor, but this is a relative hardening supported after bleaching. Technical cellulose, welded with the use of the discharge of ground liquor, after bleaching, but the difference in strength after bleaching minimum.

Fig. 13a and 13B graphically displays the test results of the same boiling cycles/bleach, as shown in Fig. 12A and 12B, only the factor of the gap depends on the number of units of the canadian standard mobility - LTR. Line 115 displays the characteristics of the pulp obtained by the use of liquor, essentially not containing RUM, line 116 shows the technical characteristics of the pulp obtained by the use of liquor, the heat-treated under pressure, line 117 shows the technical characteristics of the pulp obtained by the use of ground liquor, line 118 displays the characteristics of bleached technical cellulose obtained by the use of liquor, essentially not containing RUM, line 119 displays the characteristics of bleached pulp obtained by the use of liquor, subjected to heat treatment under pressure, the line 120 displays the characteristics of bleached technical cellulose obtained by the use of ground liquor, and the line 121 shows the characteristics when using grinding PAP machine.

Fig. 14A and 14B graphically displays the same sama 122 displays characteristics of cellulose, obtained by applying ground liquor, line 123 displays characteristics of cellulose obtained by the use of ground liquor, heat-treated under pressure, line 124 displays the characteristics of the pulp obtained by the use of liquor, essentially not containing RUM, line 125 displays the characteristics of bleached technical cellulose obtained by the use of ground liquor, line 126 displays the characteristics of bleached technical cellulose obtained by the use of liquor, essentially not containing RUM, line 127 shows the use of the PAP machine, and line 128 displays the characteristics of bleached technical cellulose obtained by the use of ground liquor, heat-treated under pressure. Fig. 14A and 14B show that the tension is reduced and in the case of cellulose obtained by the use of liquor, the heat-treated under pressure, and in the case of cellulose obtained by the use of liquor, essentially not containing RUM, however, Fig. 14B shows that the bleaching reduces the relative tensile strength technical cellulose obtained by the use of heat-treated liquor, to values smaller than the technical the ECC using the heat-treated liquor may be suitable for obtaining varieties of unbleached technical cellulose.

All discussed above laboratory cooking simulated sequence of cooking in a digester continuous MCCR" firm "Kamyr, Inc. ". Each laboratory cooking has the appropriate stage of impregnation, cooking parallel flow boiling flow in the boiler MCCR" and countercurrent washing. Typical concentrations of RUM based on the analysis of real liquor, shown in Fig. 15 for laboratory boiling cycles with three sources of liquor. Line 130 shows the use of ground liquor, line 131 displays the application of 50% ground liquor and 50% white laboratory liquor, essentially not containing RUM, and the abscissa axis line 132 shows the application of 100% white laboratory liquor. Note that in Fig. 15 when the time is zero - the beginning of the impregnation, is consistent with a situation where all used laboratory liquors are essentially did not contain RUM. This was done because there was not a reliable method of sampling liquor at this stage of cooking in the mill. Therefore, the concentration of RUM for boiling cycles using ground liquor and mix liquor 50/50 at the end of impregnation were lower than expected for such selection data and more representative concentrations were extrapolative is ntrace should its inherent tendencies throughout the cooking, moreover, concentrations gradually increase to the extraction step, and then gradually decrease during the stages of boiling flow in the boiler MCCR" and rinsing. Of course, when conducting cooking RUM fall in liquor, even in the presence of a source of liquor, essentially not containing RUM.

In Fig. 16 is shown an exemplary system 133 continuous cooking, which is based on the provisions of the present invention to obtain technical cellulose for enhanced durability. System 133 contains the usual dupreziana hydraulic digester continuous action of the company, "Kamyr, Inc., in which you are cooking technology MCCRmoreover, the treatment tank of Fig. 16 are not depicted, and the digester 124 continuous action shows. In Fig. 16 shows a modification of the conventional digester MCCR" 134 designed to implement methods of cooking with low content of RUM of the present invention.

The digester 134 includes an inlet channel 135 at the top of the boiler and the outlet channel 136 at the bottom of the boiler for the engineering of cellulose. A suspension of comminuted cellulosic fibrous material (wood chips) served from propeto the second slurry pipeline 139, which leads to the bottom heaters circulation and impregnating tank. Under the node 138 of the upper sieve is the node 140 extracting sieves, including the branching line 141, leading to the first tank 142, usually representing a group of settlers. Under the node 140 extracting SITA is the node 143 cooking sieves, which runs two pipelines, one pipeline - 144 - provides extraction (connecting with the pipe 141, and the other pipeline - 145 - leads to the pump 145'. At the junction of the pipes 144, 145 it is possible to provide the valve 146 to change the number of liquor passing through each pipe. Liquor in the pipeline 145 passes through the heater 147 and line 148, returning inside the digester 134 through the pipe 151, a hole which opens up approximately at the level of the node 143 cooking sieves. Outlet pipe 149 can also submit recycled liquid to the pipe 151 at about the level of the node 140 extracting sieves. Under the node 143 cooking sieves the node 152 wash sieves with the discharge pipe 153, leading to the pump 154, liquor passing through the heater 155 in the pipe 156 to return inside the digester 134 through the pipe 157 is approximately at the level of the sieve 15 is that it was designed, and now the value of the performance is limited by the amount of liquor that can be extracted. This limitation can be overcome by using the proposed methods, as shown schematically in Fig. 16. Since the volume of extraction in the pipe 141 is limited, it can be increased in accordance with the present invention, feeding the liquid to the extraction from the pipe 144. For example, the rate of extraction will be, when using the invention typically be about 2 t 1 t technical cellulose. In fact, 1 t black liquor 1 t technical cellulose extracted in the pipe 144 is replaced by a dilution liquor (wash liquor) from the source 158. In Fig. 16 shows that this is achieved by passing the washing liquor from the source 158 (e.g filtrate water) through the pump 159 and the valve 160, the majority of leaching liquor (for example, 1.5 tons of liquor 1 t technical cellulose), is introduced through pipe 161 down digester, whereas the remainder (for example, 1 ton of black liquor 1 t technical cellulose) is passed through the pipeline 162 in the pipe 145 to obtain the dilution liquor. In addition, white liquor, is essentially not containing RUM, from a source 163 can be further podoba 150 and/or 151. Of course, the white liquor can also apply for flushing circulation pipeline 153 (see pipeline 165) to carry out the cooking technology EMCCR". Arrow 166 flow displays the area of parallel flow in the digester 134. In the modification illustrated in Fig. 16, the flow in the zone 167 cooking technology MCCR" will contain more pure lye with reduced content of RUM, which will improve results in terms of technical strength of the cellulose and in this case will also affect the performance increase digester 134.

The impact of the modifications illustrated in Fig. 16, the concentration of RUM was investigated using a dynamic computer model digester continuous action of the company, "Kamyr, Inc. Preliminary results of this theoretical study is schematically illustrated in Fig. 17. In Fig. 17 shows the comparison of changes in the concentration of RUM in a conventional digester MCCR" and in the digester shown in Fig. 16, the results for conventional digester MCCRdisplays the line 168, and the results to the digester shown in Fig. 16, line 169.

How can Ovide what uranium RUM, and also reduces the level of RUM in countercurrent sent back to the node 140 extracting sieves. In addition, the downward countercurrent leaching liquor contains less RUM, because less RUM served with technical cellulose. Line graphs 170, 171, representing some lines 168, 169, indicate that in the area of cooking countercurrent concentration RUM always increases in the direction of flow of the liquor. That is, when the counter is boiling and the accumulation of RUM, when the flow passes through falling down a lot of chips.

Thus, Fig. 16 and 17 illustrate the dramatic influence of only a single stage extraction-dilution profile RUM in a digester continuous action, and this reduction RUM can exert a dramatic influence on the strength of the resulting technical cellulose.

In Fig. 18 shown other ways of making modifications associated with grinding, corresponding to the invention. There is also a digester 134, which is part dupreziana hydraulic digester system. Because many of the constituent parts of the structure shown in Fig. 16 and 18, are the same, they are marked the same positions. Details will be apisak even more dramatic reductions RUM. In this embodiment, the sieve 140, 143 are reversed compared to the variant shown in Fig. 16, and also between nodes 138, 143 sit there another site sieves 173. Site sieves 173 is a site scoring sieves and in accordance with the invention from this node departs outlet pipe 174, providing extraction in the sump 142.

In the variant shown in Fig. 18, as one specific example of operation, two tons of liquor per ton of technical cellulose will be extracted by pipeline 174, and four tons of liquor per ton of technical cellulose - pipe 141. Dilution liquor will additionally be supplied by pipeline 162 and white liquor, is essentially not containing RUM - pipe 164. This will give depicted in Fig. 18 threads 176, 177 and thus, the digester 134 can be characterized as providing consistently: parallel flow, counter flow, parallel flow, and again the counter (and it can be called a continuous cooking with a change of flow direction).

In Fig. 19 depicts another cooking system 179 corresponding to the present invention. In this dupreziana system impregnating tank 180 is shown having inlet of CAEA in a conventional high pressure feeder, while the white liquor is additionally served by pipeline 184. The liquid discharged by pipeline 185, you can skip in the input node between the first tank 186 and the second sump 187. A suspension of the pipeline 182 imposed on the pipeline 188 in the upper part of the digester 189 with design 190 "stilling well" from which the liquor is directed to a pipe 191 and recycle down impregnating tank 180. When recirculation liquor is heated in the heater 192.

The digester 189 also has a node 194 scoring baskets off of it a branch pipe 195, which is in this case connected to the recirculated fluid in the pipe 191. Node 196 cooking sieves is located under the node 184 scoring sieve and the liquid is discharged through pipes 197 passing through the valve 198 in the pipeline 199, and the optional part of the liquid passes from the valve 198, going through the pipeline 200, the tank 186. The fluid in the pipeline 199 dilute the liquor with low content of RUM, such as white liquor 201, essentially not containing RUM, and the filtrate 202 before passing through the heater 203 and re-injected into the digester 189 pipeline 204 is approximately at the level of the node 196 sieves. Node 206 extracting sieve AET the pipeline 209 recirculation, which you can additionally serve white liquor 210 before liquor passes through the heater, and the flow re-enters it through the pipeline 212 approximately at the level of the node 208 washing sieves. The filtrate, representing a wash liquor, and additionally serves on the pipeline 213, while the technical cellulose divert the pipeline 193.

Note that the system 179 has the potential for extraction of pipeline 197 through the valve 198 in the pipeline 200. Dilution liquid in the filtrate also preferably be sent by pipeline 214 in the pipeline 182, while the white liquor, is essentially not containing RUM, impose additional pipeline 214'.

In Fig. 20 depicts odniesieniu hydraulic digester, modified in accordance with the provisions of the present invention, and this modification also includes two sets of cooking forces, as usual. This increases the potential for entering the extraction/dilution in two additional places.

Odniesienia hydraulic digester system 215 includes a conventional integral part type bin chip 216, tank steaming 217, high-pressure distributor (device is ine 220 digester 221 continuous and outlet channel 222 for ready technical cellulose, at the bottom of the digester 221. Part of the liquid away on the pipe 223 and recycle back into the high pressure feeder 218. Cooking SITA are located below the pipe 223, this can be implemented, for example, in the form of node 224 of the first cooking sieves and node 225 of the second cooking sieve.

With the node 224 of the first cooking sieves associated with the first means for recycling the first portion of the liquid withdrawn from node 224 cooking sieves inside the digester 221, including the pipeline 226, pump 227 and the heater 228 to the pipeline 229 re-enter at about the level of the node 224 sieves. It is possible to provide the valve 230 for extraction before the heater 228 in the pipeline 231, white diluting liquor, such as white liquor (about 10% of the total number of used liquor) is additionally served by pipeline 232 immediately before the heater 228.

Second means for recycling part of the exhaust liquor and extraction of the rest of the exhaust liquor provided to the second node cooking sieves 225. This second system includes a pipeline 235, pump 236, the heater 237, valve 238 and the pipe 239 to re-enter. One part of the liquid Supplement dilution liquid in the pipe 242 is of eloka extracted by pipeline 240. Thus, the concentration of RUM significantly reduced in the cooking area near the nodes 224, 225 of the Sith.

Below the node 225 of the second cooking sieves is the node 245 extracting sieve having a pipe 246 extending from this node to the valve 247. From the valve 247 one branch of the pipeline passes to the first sump 249 disposal system, which typically includes a second settling tank 250. Part of the liquor in the pipeline 246 can be recycled through valve guide 247 in the pipeline 251.

The digester 221 also contains the node 253 of the third sieve below the node 245 extracting sieve and comprising a valve 254 with the branching branch in the discharge pipe 255 and line 256 extraction. That is, depending on the valve position 247, 254, fluid may leak from the pipeline 246 in the pipeline 255 or from the pipeline 256 in the pipe 248.

The pipeline 255 through the pump 257 is connected to the heater 260 and the return line 261 approximately at the level of the node 253 of the third sieve. Dilution liquor is additionally fed into the pipeline 255 through the heater 260 and white liquor (for example, about 15% of the white liquor used for cooking) are also available on t by pipeline 259.

The digester 221 also includes the node 263 wash sieves containing the discharge pipe 264, which can additionally serve white liquor from a source 233 (for example, 15% of the total of white liquor to the process) pipeline 265. Provided by the pump 266, heater 267 and the return line 268 to reenter the reserved liquid approximately above the level of the node 263 sieves. In addition, serves wash filtrate below the node 263 sieve pipeline 269 connected to a source of wash filtrate 243.

In one exemplary process corresponding to the invention, 55% of the white liquor used for processing technical cellulose, advanced submitted by pipeline 271 for impregnation of chips when it is transported through the high-pressure device 218 submission and sent to the pipeline 219, 5% were filed in the high-pressure device 218 feed pipe 272, 10% extra was filed jointly by pipeline 232, 241 (for example, by 5% each) and 15% was applied on each of the pipelines 258, 265.

Using odniesieniu hydraulic unit 215 continuous cooking, is shown in Fig. 20, it will be possible podderjival, you can ensure that at least each of the following three modes:

(A) Extended modified continuous cooking with extraction-dilution on the bottom of the cooking sieves. In this mode, the digester 221 works with conventional extraction in the pipe 246 and extended modified continuous cooking, and white liquor are served in the pipeline 232, 258, 265. Extraction also occurs in the pipe 240 for filing the appropriate dilution liquor pipeline 242 of 243 source of wash filtrate, resulting liquor with low content of RUM runs either parallel flow or counterflow between the node 245 extracting sieves and node 225 of the lower cooking sieves. Will take place in parallel flow or counter-current is dependent on the volume of extraction in pipelines 240, 246.

(B) Extended modified continuous cooking with extraction/dilution in the circulation loop of a modified continuous cooking. In this mode, all threads that have just been described in relation to the mode (A), are also used, and in addition the extraction circuit, consisting of a pipe 256 and valve 247, 254, managed to obespechevat 248. Dilution fluid to replenish losses as a result of this extraction is served by pipeline 259, resulting in between nodes 245, 253 sit fluid flows in countercurrent mode and a low content of RUM.

(B) Impregnation with offset and extraction with thinning on the top of the cooking sieves. This mode can be used separately or in combination with conventional modified continuous cooking process or in addition to the above modes (a) and (B). This mode enables the extraction node 224 of the upper sieve, as indicated by pipeline 231, under control of valve 230 and thinning white liquor supplied through a pipeline 232. You can provide additional dilution from the pipeline 259 (Fig. 20 not shown). This leads to impregnation with offset, which occurs when the counter-flow in the intake channel in the digester is initiated due to extraction, and the liquor contained in the incoming chips. The low content of the liquor in the chip will cause the hydraulically filled digester 221 pumping flow dilution back to an input channel 220, resulting in the backflow of liquor with low content of RUM.

The system 215, support okislennye modified form of threads you can use by applying the principles of low concentration RUM corresponding to the present invention, to obtain technical cellulose for enhanced durability.

Note that all variants of the embodiment illustrated in Fig. 16 and 18-20, can be modified in relation to existing mills, and the precise instructions of how to use various pieces of equipment will depend on the specific mill on the basis of which to build the technology. All this will provide the above benefits decreased level of RUM, i.e. high strength, high belibaste, reduced consumption of effective alkali and/or lower H-factor. For the configuration shown in Fig. 19 is best shown in Fig. 21-25.

In Fig. 19 POS. 185 refers to the first extraction, POS. 200 - second extraction, POS. 207 - the third extraction, POS. 214 - to the first dilution, POS. 202 - second dilution, and POS. 213 - the third dilution.

In Fig. 21 displayed based on computer simulation comparison of profiles RUM for standard cooking "EMCC(R)" and similar cooking in accordance with the invention using the system shown in Fig. 19, to implement long WARC is strairway sit, and the white liquor is introduced into the normal contours of the cooking circulation and flushing circulation, creating a stream of liquor from the top of the digester to the usual extracting the Sith, which is a parallel flow, while the flow in the rest of the digester is countercurrent. In accordance with the model of long parallel flow depicted in Fig. 21, the third extraction 207 represents the main extraction, so cooking in the parallel flow occurs throughout the entire flow path to the node 206 of the Sith. In Fig. 21 conventional cooking technology EMCC(R)displays the line graph 275, and cooking in accordance with the regime long cooking in a parallel flow is illustrated by the line graph 276. In the computer model, the results of the calculation which graphs are drawn in Fig. 21, the rate of tonnage was 1200 medium-dry metric ton/day, and the distribution of white liquor was as follows: 60% on pipeline impregnation 184, 5% - on pipe bottom circulation, 214', and 15% of the pipeline 201 circulation boiler MCC(R)" and 20% by pipeline 210 flushing circulation. Pipeline 213 additionally served to 1.5 tons of liquor 1 t technical cellulose, and as the liquor used wash filtrate to brochosome cooking, it grows on stage countercurrent. Therefore, this kind of prolonged cooking countercurrent gives a small improvement in sense (reduction - approx. translat.) the concentration of RUM (line 276). Although the computer model itself has some limitations, Fig. 21 still shows that it is possible to change the concentration of RUM in the process of cooking.

In Fig. 22 displays theoretical effect of an additional supply of white liquor by pipeline 201 and diluted liquor with a low concentration of RUM pipeline 202, shown in Fig. 19. In Fig. 22 displayed characteristics corresponding to the additional feed pipe 202 1.0 t liquor per 1 ton of wash filtrate technical cellulose along with the flow of white liquor in an amount of 0.6 t 1 t technical cellulose. The corresponding flow of liquor in the amount of 1.6 t 1 t technical cellulose was extracted by pipeline 200. As can be seen from the graph line 277, in comparison with the plot line 276 in Fig. 21, the resulting concentration of RUM drops sharply between the Sith 196, 206.

In Fig. 23 shows the effect of changes in the distribution of wash filtrate conduits 202 and 213. In this case, the pipes 213 and 202 distributed shared is the key for 1/2 dilution liquor, added by pipeline 202, and line graph 280 displays 2/3 dilution liquor to be added to the pipeline 202 (the rest of dilution liquor in each case was filed by pipeline 213). Thus, it is clear that the profile RUM is undergoing significant changes with the change of the dilution flow and the greater the dilution takes place in the cooking area, the more reduced here, the concentration of RUM (although increases in the zone of leaching).

In Fig. 24 illustrates theoretical effect of changes in the extraction pipeline 200. Line graph 281 predicts profile RUM in the event extraction pipeline 200 of 1.35 t liquor 1 t technical cellulose, line graph 282 - in the event extraction pipeline 200 of 1.85 t liquor 1 t technical pulp and line 282 in the case of the extraction pipeline 200 2.6 t liquor 1 t technical cellulose. In each case, the total number of dilution liquor 2.5 t 1 t technical cellulose were distributed equally through the pipes 202 and 213 and an additional amount of white liquor, amounting to 0.6 t 1 t technical cellulose: submitted by pipeline 201. In Fig. 24 it is clear that theoretical concentration of RUM in the area of cooking humanitarization, you can change the extraction to get the pressure drop for extracting the sieve without excessively strong negative impact on the profile of the RUM.

In Fig. 25 shows the influence of the extraction pipeline 185 (in the upper part of the impregnating tank 180) with the creation of the impregnation zone countercurrent in the implementation of the long cooking in a parallel flow with dilution. In this case, the reporting data impregnation tank in parallel flow are identical to those shown in Fig. 22. The stream extraction 185 - 1.1 t liquor 1 t technical cellulose extracted liquor was replaced not wash filtrate, and white liquor is supplied through pipe 184. In previous models, shown in Fig. 21-24, 70% of the white liquor is additionally served by pipeline 184 and 5% by pipeline 214', in the model shown in Fig. 25, those percentages are reversed; 5% - on pipe 184 and 60% by pipeline 214'. Line graph 284 displays the results of the counter (60% of the white liquor are served by pipeline 214'). Therefore, this demonstrates that theoretical concentration of RUM and decreases in the reservoir 180 and in the area of cooking and remains comparable in magnitude in the cooking area counter. Poccia and dilution in the digester 189.

Thus, it can be noted that in accordance with the present invention a method and devices that enhance the strength of sulphate pulp by removing, minimize (e.g. by dilution) or passivation RUM at the time of any phase sulfate cooking and/or enhance other technical parameters of cellulose or its receipt. Although the invention has been illustrated and described examples of equipment that exists and the most reliable in practice at the present time and in the preferred embodiments the embodiment of such equipment, for specialists in the art it is obvious that there are numerous modifications of the invention within its scope, which should be considered consistent with the interpretation in the broadest sense of the attached claims and cover all equivalent structures, methods and products.

INSCRIPTIONS ON DRAWINGS

Fig. 1

12 - submission technical pulp from the high pressure feeder; 13 - upper circulation, return to the high pressure feeder; 16 - treatment; 16'- processing; 25 - heater; 24 - white liquor; 28 edition of the technical cellulo the spacecraft; 58 - processing; And exhaust gases; white liquor.

Fig. 2

A1 - factor gap; A2 - stretching, km

Fig. 3

A1 - factor gap; A2 - stretching, km

Fig. 4

62 - chips; 66 white liquor; 67 - tank filtrate; 68 - purge tank; 63 drive; 64 drive; 65 drive; 72 - exhaust gases; 71 - heating.

Fig. 5

84 - heater; 86 - thinning to regulate the consumption of alkali; 89 - extract; 91 - treatment to maintain low RUM; 92 - heater.

Fig. 6

Simulation of grinding. The dependence of Kappa on H-factor: A1 - Kappa; A2 is H-factor.

Fig. 7

The dependence of the consumption of effective alkali from Kappa: A1 - consumption of effective alkali, % on wood; A2 - Kappa.

Fig. 8

The dependence of the consumption of effective alkali percentage of ground lye.

A1 - effective alkali on wood, %.

Fig. 9

Comparison of reaction degree of whiteness for various technical cellulose obtained by the use of different liquors.

A1 - whiteness by MCO (ISO); A2 (unbleached technical pulp Kappa values are shown in parentheses); A3 - Kappa-factor full on the ground lye.

A1 - gap while stretching 11 miles; A2 - % ground lye.

Fig. 11

The dependence of the wear percentage ground lye.

A1 - wear at 600 LTR; A2 - % ground lye.

Fig. 12A

The dependence of tensile strength on stretching for unbleached technical cellulose.

A1 - factor gap; A2 - stretching, km

Fig. 12V

The dependence of tensile strength on stretching for bleached technical cellulose DEoD(nD):

A1 - factor gap; A2 - stretching, km

Fig. 13A

The dependence of tensile strength on the mobility for unbleached technical cellulose: A1 - factor gap; A2 - STS, LFM

Fig. 13B

The dependence of tensile strength on the mobility for bleached technical cellulose DEoD (nD). A1 - factor gap; A2 - STS, LFM

Fig. 14A

The dependence of strain on the mobility for unbleached technical cellulose.

A1 - stretching, km; A2 - STS, LFM

Fig. 15

Profile of dissolved solids. The dependence of the concentration of dissolved organic material from the cooking time.

A1-RUM (g/l); A2 - impregnation; A3 - cooking in a parallel flow; A4 - area modified cooking; A5 - zone leaching; A6 - time the full-time tank; 158 white liquor; 163 - white liquor.

Fig. 17

Predicted concentrations of RUM: a comparison of characteristics for digesters MCCR" in the normal and in the proposed embodiment, when multiple extraction/dilutions (extraction and dilution - only modified cooking sieves):

A1 - total particulate organic matter (g/l); A2 - extracting bolt (POS. 140 in Fig. 16); A3 - modified cooking sieves (POS. 143 in Fig. 16); A4 - multiple extraction (duration in hours).

Fig. 18

135 - from the impregnating tank; A1 - bottom heaters circulation and impregnating tank; 169 - white liquor; A2 - washing.

Fig. 19

183 to the high pressure feeder; 184 - white liquor; 214 - filtrate; 214' white liquor; 213 - filtrate; 210 - white liquor; 201 - white liquor; 202 - filtrate.

Fig. 20

A1 - feeding chip; 233 - source white liquor; 271 - 55% of white liquor; 272 - 5% white liquor; 226 - 10% white liquor; 258 - 15% of white liquor; 264 - 15% of white liquor; A2 for recycling; 243 - the source of wash filtrate.

Fig. 21

The predicted profiles RUM: comparison of cooking "EMCCR" and long cooking in a parallel thread:

A1 - General Konzentrat the giving standard and offer boiling cycles in parallel flow with numerous extraction/dilutions (extraction and dilution - only outlet/extracting sieves):

A1 - total particulate organic matter (g/l); A2 is the time (hours).

Fig. 23

Profiles RUM: Extraction/dilution contours diversion/extraction. The effect of changes in the distribution of diluent (CBF):

A1 - total particulate organic matter (g/l); A2 is the time (hours).

Fig. 24

The predicted profiles RUM: extraction/dilution contours diversion/extraction. The effect of the extraction on delivery/extracting the Sith.

A1 is the total concentration of solid organic substances (g/l); A2 is the time (hours).

Fig. 25

Predicted profiles of RUM: a comparison of impregnating tank in case of parallel flow and counter flow (extraction and dilution - only outlet/extracting sieves):

A1 - total particulate organic matter (g/l); A2 is the time (hours).

1. Method for continuous production of pulp chemical pulp using at least one node sieves in a digester, comprising the following stages: a) a transmission in the direction of node sieve and a liquid suspension of the crushed pulp fiber material with concentratie nicesly cellulose, H-factor, the amount of effective alkali and/or belmost; b) allocating a portion of the fluid with the specified concentration of RUM from the suspension of the node sieve; C) recycling at least part of the allotted fluid through the recirculation loop back to the digester to the node sieve; g) introduction of cooking liquor in the recirculation circuit, characterized in that d) dilution liquor having a concentration of RUM, significantly lower than the concentration at the stage (a) is introduced into the recirculation loop; (e) recycling in the digester is carried out at concentrations of RUM in the returned fluid, which is significantly lower concentrations of RUM at the stage of (a) and different from the concentration of RUM on stage (d) for a positive impact on the strength of the masses, N-factor, the amount of effective alkali and/or belmost.

2. The method according to p. 1, comprising the additional step between stages (b) and (C) providing for the transmission of the first part of the liquid reserved from step (b), regeneration or other treatment outside of the digester and recycling the second part of the stage ().

3. The method according to p. 2, wherein stage (b)-(g) perform such a way that essentially the entire liquor, remote at the stage (b), pass on regenerat the stages (d) and (e).

4. The method according to any of the preceding paragraphs, including the use of the second node sieve at a distance above the first specified node sieves, which includes additional stages (3) and (and), carried out before stage (a), i.e., (C) passing a liquid suspension of the crushed pulp fiber material in the direction of the node of the second sieve and for him, and the suspension dissolve the contained organic material, and (or) disposal of liquid with dissolved organic material from the slurry in the node of the second sieve and passing it on regeneration or other treatment outside the digester.

5. The method according to any of paragraphs.1 to 3, providing for the use of the second node sieve at a distance below the first node sieves, which includes additional stages (C) and (and), i.e., (C) passing a liquid suspension of the crushed pulp fiber material in the direction of the node of the second sieve and for him, and the suspension dissolve the contained organic material, and (or) disposal of liquid with dissolved organic material from the slurry in the node of the second sieve and passing it on regeneration or other treatment outside the digester.

6. The method according to any of p the combination.

7. The method according to any of the preceding paragraphs, in which stage (a) - (e) is carried out before cooking or at the beginning of cooking.

8. The method according to any of the preceding paragraphs, in which stage (a) to (I) provide to maintain the level of dissolved organic material below 100 g/l during essentially the entire cooking.

9. The method according to any of the preceding paragraphs, in which stage (a) to (I) provide to maintain the level of dissolved organic material below 50 g/l for essentially all of the cooking.

10. The method according to any of the preceding paragraphs, in which stage (a) to (I) provide to maintain the level of dissolved hemicellulose, comprising 15 g/l or less, for essentially all of the cooking.

11. The method according to any of the preceding paragraphs, comprising the additional step (R) between stages (d) and (e), which involves the heating of the liquid in the recirculation loop before returning the liquid in the recirculation loop to the digester.

12. The digester continuous with the top and bottom, which includes connected to the top inlet connection to be cooked pulp material connected to the bottom of vypusknomu connected to the recirculation loop for returning the liquid in the digester at the level of the first node sieves, means for supplying cooking liquor in the first lateral pipeline, characterized in that the first discharge pipe connected to the means for feeding it replaces liquor with a low concentration of dissolved organic material (RUM).

13. The digester continuous on p. 12, wherein said cooking pot includes at least one node of the second sieve, and at least one node of the second sieve has a second lateral pipeline.

14. The digester continuous on p. 13, in which the node of the second sieve placed over the site of the first sieve.

15. The digester continuous action under item 13 or 14, in which the node of the second sieve is placed under the node of the first sieve and operatively connected to the regeneration system or other processing system outside the digester.

16. The digester continuous operation according to any one of paragraphs.12 to 15, wherein said cooking pot includes means for passing the first portion of the liquor through remote node of the first sieve, regeneration or other treatment outside the digester.

17. The digester continuous operation according to any one of paragraphs.12 - 16, additionally comprising the area protectve according to any one of paragraphs.12 - 16, additionally comprising an area of cocurrent continuous cooking on the specified node of the first sieve.

19. The digester continuous operation according to any one of paragraphs.12 to 16, wherein said digester continuous action is a hydraulic digester continuous action.

20. The digester continuous operation according to any one of paragraphs.12 to 18, wherein said digester continuous action is a vapor-phase digester continuous action.

21. The digester continuous operation according to any one of paragraphs.12 to 18, wherein said digester continuous action is odniesieniu digester continuous action.

22. The digester continuous operation according to any one of paragraphs.12 to 18, wherein said digester continuous action is dupreziana digester continuous action.

Priority points:

04.05.93 on PP.1-22;

28.09.93 on PP.1-22 types of signs.

 

Same patents:

The invention relates to techniques for the production of cellulose and can be used in the pulp and paper industry

The invention relates to the pulp and paper industry, in particular to a device for processing a cellulose-containing material, such as cooking, and can improve the processing efficiency and to improve the pulp quality and selected liquor for biochemical processing or to obtain lignosulfonate

The invention relates to the pulp and paper industry, in particular to a device for processing a cellulose-containing material, such as cooking, and can improve the processing efficiency and to improve the pulp quality and selected liquor for biochemical processing or to obtain lignosulfonate

The invention relates to a method of continuous isothermal pulping at elevated pressure and temperature of the fiber material in a vertical digester

The invention relates to a vertical digester boiler for continuous cooking at elevated pressure and temperature of the fibrous material in which the flow of fibrous material and cooking liquid is carried out in the upper part of the digester

The invention relates to a reactor device and method for ozone bleaching of lignocellulosic pulp, and more particularly to a reactor that includes a rotating elements to move in the radial direction of the dispersed particles through the mass of ozonotherapy gas in corkboard mode flow

The invention relates to cellulose paper industry, namely the cooking of cellulose in aqueous-alkaline solutions, and can be used in the preparation of fibrous materials for various purposes

The invention relates to the chemical processing of cellulose-containing raw material, namely the method of microcrystalline cellulose, which is widely used as filler in pharmaceutical, food and cosmetic industry, stabilizer water-latex paints and emulsions, sorbents for chromatography, and is physiologically active substance, which improves the metabolic processes in the body

The invention relates to the pulp and paper industry, in particular to a technology for pulp for paper and chemical processing

The invention relates to a method for sulfite pulp for the production of wood-fiber mass, which use alkaline monosulfide solutions, organic solvents and derivatives of quinone

The invention relates to a method for producing pulp for the production of viscose fibers from lignocellulose deciduous, coniferous wood or annual plants, in which lignocellulose first process in the digester by means of saturated steam for prehydrolysis hemicellulose and then without reducing pressure treated with hot black liquor (–ĚSL) previous cooking to obtain sulphate pulp, and, if necessary, with the addition of fresh white liquor (WL), to neutralize the resulting acidic reaction product, resulting in digester liquor is formed neutralization (NL)

The invention relates to the pulp and paper industry, namely to receive the pulp using cooking solutions containing sodium hydroxide and polysulfides, and can be used in the preparation of fibrous materials for various purposes

The invention relates to the pulp and paper industry, namely to receive the pulp using cooking solutions containing sodium polysulfide and sodium hydroxide, which improves the flow of pulp and the degree of delignification of wood
The invention relates to the pulp and paper industry and can be used in the manufacture of pulp for chemical processing in the apparatus of continuous action type "Kamyur", having an area of diffusion washing

The invention relates to the manufacture of cellulose derivatives and relates to a method of microcrystalline cellulose, which can be used as filler in pharmaceutical and food industries, sorbent and filter material in the technique, the raw material for producing low-viscosity cellulose derivatives
Up!