DE2241673C2 - Plant for processing suspensions of fibrous materials - Google Patents

Description

The invention relates to a system for processing pulp suspensions in cellulose processing and papermaking, consisting of a reactor with one in its housing close by from the reactor inlet at equal distances from its side walls arranged cylindrical element to Constriction of the suspension flow of fibrous materials, which is carried out with the help of a pump via a pipeline system is feedable. and to generate cavitation forces in the suspension.

DE-AS 12 58 835 discloses a mixing device with a housing enclosed below Pressurized chamber to which the at least one component of the mixture is supplied is, with an annular passage adjoining the chamber, that of 2 is arranged coaxially Rotational surfaces is limited, of which the outer by the housing wall and the inner by the Jacket surface of an insert is formed and with a downstream of this passage in the direction of flow known coaxial outlet, in which the insert has a downstream end face that consists of seen on a surface perpendicular to the axis, the cross-section of the annular passage between the Housing wall and the insert is smaller than the flow cross-section of the chamber, and the outlet, the diameter of which is smaller than the inner diameter of the annular passage, by one, at least approximately, perpendicular to the axis extending, the flow cross-section after the annular Passage narrowing paragraph is formed in such a way that the particles of the mix are perpendicular to the axis directed flow component is issued, under the influence of which they collide before the mixing ί well flows through the outlet. Because the flow passage is arranged coaxially to the cylindrical flow passage Insert through which the component to be admixed is introduced, the flow cross-section ring-shaped constricts and the flow cross-section then

ι α is narrowed again by a narrowing paragraph, there is a turbulence behind the insert mixing currents, but practically no cavitation.

From DE-AS 12 75 513 a device for

ι ϊ dispersing mixed with solids, in particular fibrous liquids, known by means of liquid pipes connected to the supply line, which has 2 or more liquid pipes, their nozzle bodies in a common housing are movably mounted in such a way that they alternate with the supply line of the liquid to be dispersed or can be connected to an additional detergent line. A liquid whistle is used T-shaped tongue that can be adjusted axially to the jet nozzle

r> used, with the sound vibrations in the liquid flow are generated, which are to assist the dispersing. Significant cavitation occurs not on.

In DE-AS 12 34 678 a device for atomizing liquids in air or gases, especially for atomizing burners, assumed to be known, in which the mixture components are made Liquid and air or gas initially under multiple cavitation effects on vortex-generating guide surfaces

i'j chen intimately mixed with atomization of the liquid and then nebulized by impact with a sound-generating baffle. That’s what it’s about the problem of the atomization of liquids in air or gas.

• To in the field of cellulose and paper production are procedures and systems / for the implementation of a a whole range of technological processes associated with related to the processing of fibrous materials. This includes the de-resinification of the cellulose and

4i half-cellulose, which is grinding and de-resinating at the same time cellulose and pulp, bleaching. Chlorinating, and letting the liquid pass through a Nozzle with supply of another component by means of an injector into the avitation zone. The in that However, cavitation forces generated by a hydrodynamic stream flowing through an injector are available only at a low intensity. This allows the erosion activity to treat suspensions of fibers very little

With the help of a series of experimental and theoretical work in the field of study of the Cavitation has been shown that the erosion activity of cavitation is dependent on the exponential of the pulsation pressure size in the cavitation zone. The pulsation pressure is hanging in turn depends on the shape of the narrowing of the flow and the type of body to be flown around. the Cavitation excited by narrowing the current with the help of a nozzle, is weak and sufficient for that Mix out any components in the liquid. The ejection changes one other components in the cavitation zone their nature and leads to a reduction in the

Degree of turbulence of the cavitation tavern and to a significant reduction in the Struchalew frequency of the vortex process. This further reduces the erosion activity of cavitation. It is also common knowledge that the supply of gaseous components into the cavitation zone is inexpedient, since in this Fall the character of the cavitation process decreases, and its erosion activity decreases to zero

The present invention has for its object to provide a a.nlage for the processing of pulp suspensions in the cellulose processing and paper manufacture of the aforementioned type provide that allows to exercise a high degree of cavitation on the to be processed pulp suspensions, whereby the processing of fiber suspensions intensified ι ί and the quality the products produced with this can be increased.

This is achieved according to the invention in a system of the type mentioned at the beginning by the features characterized in claim 1. This simple and efficient construction, the erosion activity on the devices with just eindimensiona'er current narrowing and aperiodic Wirbelbüdung is how they are caused by narrowing of the nozzle and in terrace form arranged flow obstacles?. => Increased to 8- 12 times. The reason for this can be seen in the fact that the system according to the invention creates a two-dimensional flow constriction, which is characterized by a two-dimensional vortex shedding and not a circumferential or w circular constriction, as in nozzles or with a coaxial alignment of the body to be flowed around in the interior of the hydrodynamic flow he follows.

In preferred embodiments of the system according to the invention, at the inlet of the confuser along r> its circular line tube inserts for the introduction of chemical Reagents attached to the suspension stream of fibrous materials.

The erosion activity of cavitation forces can in advantageous development are thereby increased. that the cylindrical surface of the flow around ElemiMtes with a layer of elastic material über'.T / ogen and / or in the reactor behind the cylindrical a vibrator is attached to the body to be flown along its axis. 4S

As explained in more detail below. cause these measures in the strong cavitation field generated according to the invention the addition of additional, pulsation vortices synchronous with the generated cavitation field the Kavitai'on Cavern. what the amplitude w de one's own pulsations and thus to further increase the achieved high erosion effect able.

7u the processing methods for pulp suspensions in the pulp and paper industry, their Intensification achieved by the device according to the invention wire ', include: resin removal from cellulose. Bleaching of the wood mass and the cellulose. Chlorination of cellulose. Increasing the ability to react Cellulose for chemical processing, simultaneous grinding and entharing of cellulose, activation and the acetylation of cellulose for chemical processing, the impregnation of fibers, washing out of cellulose, mercerising and dissolving the xanthate of cellulose, coloring From paper pulp, the purification of sewage from Fibers as well as the deflocculation of the paper pulp.

To remove resin from the fibrous materials, dispersants can be added to the suspension before its flow is narrowed in an amount of 0.5-1.0%, based on the fiber weight, are introduced, it being expedient is to carry out the pulping of the fibers at the same time as the resin removal.

To bleach the fibrous materials, bleaching reagents can be added to the suspension before its flow is narrowed be introduced, it is expedient to simultaneously with the bleaching of the fibrous materials grind.

To chlorinate the fibers, gaseous chlorine can be introduced before their flow is narrowed will.

To increase the reactivity of the fibrous materials can be in the suspension before the narrowing of their Stromes surfactants are introduced.

In order to activate the fibrous materials, inclusion5 substances can be added to the suspension before its flow is narrowed to be introduced.

To atetylate the fibrous materials, the suspension before the constriction i ^; a catalyst can be introduced into the stream.

To impregnate the fibrous material, an impregnating agent can be added to the suspension before its flow is narrowed Cooking solution can be introduced.

To wash out the fibrous material, water can be added to the suspension before its flow is narrowed to be introduced

For mercerization of the fibrous materials, a Lye to be introduced.

In order to dissolve the cellulose xanthogenate, the suspension can enter before the narrowing of its flow Solvents are introduced.

A pigment can be added to the suspension before its flow is narrowed to color the fibrous material to be introduced.

In order to clean the waste water from fibrous materials, air can be introduced into the suspension of its flow.

The system according to the invention makes use of the hydrodynamic flow cavitation a narrowing of the flow of a fiber suspension the flow around a cavitation exciter of certain Form emerges.

In the event of a strong pressure drop, cavitation nuclei grow behind the element to be flown around, ie the air and gas bubbles that are in the micro-. Macro- and submicropores as well as in the capillaries of the fibers are located, up to vesicles with dimensions of 0.1 to 1.0 mm. and in the zone of increased pressure; a large reduction in their dimensions. When the vesicles close, they form in the cavitation track (cavern) in the microspaces of the si'spi. is on shock waves that amount to several thousand atmospheres. The fibers are deformed many times under the influence of these impulses. There e \ followed by delamination and fibrillation of the fiber walls, wns contributes to the development of an active fiber surface and thus to a more rapid penetration of chemical reagents in the interior of the fiber. The fibers subjected to the cavitation effect easily react with other components introduced into their suspension, which is why the reaction rates of the processes when using the system according to the invention are only determined by the rates of the chemical reactions themselves.

The cavitation forces express themselves in suddenly changing pressure drops, in temperature changes.

rungen, an intensive Durehmischen under influence of shock waves and microcurrents. as well as in their erosion activity with respect to those to be treated Suspension. Therefore the excitation of an erosion-active stage of cavitation is in the hydrodynamic Stream of suspensions to be treated of great interest.

It is of great importance that the opening picture that which is used as a cavitation exciter in the narrowing hydrodynamic flow transverse cylinder has a flat, two-dimensional vortex course that extends over the whole Transverse surface of the suspension flow widespread. The cavern has the greatest turbulence that the Degree of their relaxation is determined, whereby the vortex flow from the cylindrical body is strictly periodic Bears character with Struchalew frequency. The totality of the characteristics mentioned above is determined the maximum erosion activity of the cavitation cavern. The by flow around an element of cylindrical Cavitation caused by the shape corresponds to the two-dimensional surface flow of the vortex flow.

Research has shown that, as mentioned earlier, other forms of bodies have a hydrodynamic Generate cavitation which after erosion activity is 8 to 12 times less than that in the track behind the cylindrical body.

It must be emphasized that the intensity of the cavitation is a two-dimensional flow around a surface at the expense of an active change in the amplitude of pulsations with Struchalew frequencies enlarged by adding additional and synchronous impulses to the field of hydrodynamic pulsations can be.

Since the potential nuclei of cavitation are concentrated directly in the fibers, this is what offers Possibility, under the conditions that a hydrodynamic Cause cavitation, easily tearing down weakly reacting layers of the cell wall effect and increase the active fiber surface without accumulation of low molecular weight fractions. the The selectivity of the process is favored by the nature of the pulp fibers, since the primary wall (the weakly reacting layer) is more porous. as the outer layer of the secondary wall, while the Outer layer of the secondary wall is more porous. as the inner layer of the secondary wall.

In this way both the peculiarities of the hydrodynamic process of the Flow cavitation as well as the characteristics of the material to be treated are taken into account

Research work on changing the nature of the cell wall of cellulose showed one high effectiveness of the system according to the invention for treating fibrous materials.

To further explain the system according to the invention, a preferred embodiment is described below; the system in which a cavitation disfigured reactor called

The reactor represents a pipeline with right-angled Cross-section, which provides a convenient attachment of the serving to narrow the. Suspension flow The element with a cylindrical shape is located near the entry into the reactor equidistant from its side walls and arranged in such a way that the Mantslünie the cylindrical Surface of the element perpendicular to the direction of flow of the suspension stimulates such an arrangement

tion of the cylinder ensures the periodic formation of eddies in the two-dimensional surface flow the suspension and a free space in the reactor, which helps to create a regular structure . the cavitation cavern is necessary.

A confusor and a diffuser connect the reactor with a pipeline system and ensure a speedy operation Movement of the suspension flow in the reactor.

The raw batches for the supply of chemical

in reagents are at the entrance of the confuser along its Circle line attached in such a way that it does not damage the structure of the cavitation zone and thereby its Increase erosion activity.

A coating of the cylindrical surface of the flowed element with a layer of elastic Material and the presence of a vibrator in the reactor increase the erosion activity of the Cavitation, which is due to it. that the addition of additional and with the cavitation field synchronous pulsation vortices of the cavitation cavern to the cavitation field actively the amplitude of its own Pulsations with Struchalew frequencies enlarged.

The transmitter installed in the reactor for measuring the erosion activity of the cavitation field is used for determination the optimal parameters of the hydrodynamic flow. The following is an embodiment of the invention described with reference to the drawings. It is indicated

F i g. 1 schematically shows a system for processing pulp suspensions;

F i g. 2 shows a reactor of the plant according to the invention in longitudinal section and

F i g. 3 another embodiment of the reactor.

The system shown in the drawings consists of: A reactor 1 (Fig. 1), one with it through the Pipeline 2 connected pump 3, which through the pipeline 4 with the container 5 for the return circulation the suspension is connected, which in turn is connected by the pipeline 7 to an overflow container 6 is. The reactor 1 is connected to the overflow container 6 by the pipeline 2 to which the vertical section of the pipeline 8 belongs. The overflow container 6 is also through the pipeline 9 connected to a container IO for finished products.

In the housing 11 (Fig.2) of the reactor, which has a rectangular cross-section. the cylindrical flow around element 12 is arranged in the vicinity of the inlet at equal distances "a" from its side walls. The element 12 is arranged in such a way that the generatrix of its cylindrical surface is perpendicular to the flow direction of the suspension (indicated by arrow ^ is located

On the side of the suspension inlet is the reactor housing with the confuser 13 and on the The outlet side is connected to the diffuser 14.

At the entrance of the confuser 13 are pipe attachments 15 along its circular line for the introduction of chemical Reagents placed in the suspension stream of fibrous materials

Another embodiment of the reactor provides a coating 16 (FIG. 3) of the cylindrical element 12 with elastic material, for example with rubber and the arrangement of a vibrator 17 along the Reactor axis behind the cylindrical element 12 in front.

In reactor 1 is the transmitter 18 (an underwater listening device) for measuring the erosion activity of the cavitation field with the aid of the analyzer ^ 19

The system described above operates as follows.

The fiber suspension of the material to be processed runs with a concentration of up to 8% via the pipeline 20 (Fig.l) into the container 5 for the return circulation. From the container for the return circulation, the suspension enters the pump 3 via the pipeline 4 and is fed to the reactor 1 via the pipeline 2 through the confuser 13 under a pressure of over 30 to 40 m water column, which is generated by this pump . Chemical reagents are introduced into the suspension flow via the pipe attachments 15 mounted in the confuser. A hydrodynamic cavitation field is created at the widening point of the narrowed suspension jet, which has an intensifying effect when the fibrous materials are processed. The suspension of fibrous materials processed in the reactor runs through the diffuser 14 and the pipe 2, to which the vertical part of the pipe R belongs, into the overflow tank 6. A part of the suspension flow flows from the overflow container via the pipeline 9 into the container 10 for finished production, while the main flow of the suspension is directed via the pipeline 7 into the container 5 for return circulation. The treated suspension is fed from the container 10 into the production process (indicated by arrow "B").

The degree of processing of the suspension depends on the assumed size of the return coefficient »B, according to which the choice of performance of the Pump is hit.

The intensity of the cavitation field in the reactor is determined with the aid of the intensity analyzer 19 from the transmitter 18 (the underwater listening device) a Signal gets.

The intensity of the cavitation is regulated by adjusting the height of the vertical part of the pipe 8 changes. By changing the column height of the suspension flow or the parameters of the flow such a strength of the pressure is achieved in the reactor that it allows a cavitation field with optimal To gain erosion activity.

The functional principle of the analyzer is based on that the sound pressure determined by this device is directly proportional to the erosion activity of the cavitation field is.

In some types of treatment of the fiber suspension, such as in the process of increasing it Responsiveness, it is recommended to increase the erosion activity of the cavitation field, what with the help of the in FIG. 3 shown reactor can be accomplished.

The erosion activity of cavitation can be increased 6 to 8 times, which is not done by Enlargement of the overall efficiency of the system can be achieved.

The following are examples of the operating conditions and parameters for performing some technological Process of cellulose and paper production with processing of pulp suspensions.

example 1

A fiber suspension of bleached sulphate leaf cellulose to be detached is made with a concentration of up to 5% fed to the reactor with the help of a pump at the point of constriction of the Suspension jet, a hydrodynamic cavitation field is created by a transverse cylinder, which causes a separation of the resin from the fiber and its emulsification in the liquid medium. To the Shortening the resin removal process allows dispersants in the suspension before the narrowing of its flow in an amount of 0.5 to 1.0% based on the weight of the fiber. The The recirculation of the suspension through the reactor can be reduced up to 5 times.

As a result of the treatment, the resin content in the cellulose was reduced by 30 to 60%, While with the same power consumption, the resin content by only 10 to 15% with the help of known devices is decreased.

Example 2

A fiber suspension made of fibers to be ground at the same time and non-bleached sulphite cellulose that is to be de-resinified is made from the cellulose with a concentration of up to 4% Container for the return circulation with a pump in the

iö reactor passed. At the narrowing part of the suspension jet, a transverse cylinder creates a hydrodynamic cavitation field that has a fibrillating effect on the fiber material and causes resin particles to be separated from the latter. The suspension is recirculated through the reactor 15 to 20 times, the emulsification of the resin particles taking place without the introduction of chemical dispersants. Before it is used in the production process, the fiber suspension is dewatered up to a concentration of 6-7%.

As a result of the treatment, the resin content in the cellulose was reduced by 30 to 40%, an increase in the degree of grinding by 2 to 3 SR and an increase in some physical-mechanical Key figures achieved by 5%.

Example 3

A fiber suspension intended for bleaching wood pulp with a concentration of 4 to 6% is conveyed from the recirculation tank into the reactor with the help of a pump. At the point of constriction of the Suspension jet, a hydrodynamic cavitation field is created by a transverse cylinder, that intensifies the bleaching process 1.0 to 1.5 minutes introduced components of a bleaching solution: sodium silicate, hydrogen peroxide And caustic soda. The caustic soda is made in two steps with an intermediate control of the pH value of the medium was introduced until pH = 10.2 was reached.

Control of the bleaching process, d. H. the increase in the whiteness of the wood mass is determined by determination the whiteness of casts carried out on the Zeiss leukometer

The total duration of the bleaching process is 15 minutes at a temperature of the suspension of 45 to 50 ° C.
As a result of the treatment, a reduction in bleaching time of 12 to 16 fold was achieved with an increase in whiteness of 5.5 units and with other data unchanged compared to the use of known devices

Example 4
^v

A fiber suspension of sulphite Iufose to be chlorinated with a concentration of 3 to 4 ° / b and a temperature of 15 to 20 ° C from the container for

Return flow is passed into the reactor with the aid of a pump.

At the point of constriction of the suspension flow, a cylinder is placed in the reactor through a transverse cylinder hydrodynamic cavitation field created that the The chlorination process intensified.

Due to the pipe attachments in the confuser, the whole process is even gaseous CWo r initiated. The coefficient of return when the cellulose is chlorinated is 15 until 20.

As a result of the treatment, the general stages of chlorination were shortened by 2 times and a reduction in the use of chlorine and chemicals during the bleaching and refining stage this cellulose achieved. The increase in whiteness by 2 to 5 units is due to an increase in physical-mechanical indicators by 4 to 6% and a reduction in the degree of contamination by 30% accompanied.

Example 5

A fiber suspension of bleaching to lind to zermahlender sulfite is conducted at a concentration of 3 to 4% and a temperature of 40 to 5O ⁰ C from d? M rear circulation tank by means of a pump into the reactor at the same time.

At the point of constriction of the suspension jet, a cylinder is placed in the reactor through a transverse cylinder hydrodynamic cavitation field created, which intensifies the bleaching process and at the same time the fiber suspension fibrillated. The return coefficient is 10 to 15.

Chemical bleaching reagents are fed in via the tube attachments arranged in the confuser. After treatment in the hydrodynamic cavitation field, the cellulose becomes known with the help of Process washed out.

As a result of the treatment there was an increase in the physical-mechanical indicators of production achieved by 5 to 6% with a simultaneous increase in whiteness of 9 units.

Example 7 Example 6

45

A fiber suspension of cellulose to be treated to increase the reactivity is passed for chemical treatment with a concentration of up to 4% and a temperature of 20 to 30 ^° C. from the recirculation tank with a pump into the reactor

At the point of constriction of the suspension jet, a transverse cylinder creates a hydrodynamic Created cavitation field that exerts an action on the substance to be treated Return coefficient is 25 to 30.

As a result of the treatment was an increase in the responsiveness of 80/11% CS ₂ / NaOH, as it was previously possible to achieve at 60/11% CS ₂ / NaOH, wherein the xanthate is a transparent and rapidly filter transmitting viscose represents

An examination of the fiber microstructure also showed that the treatment of the fiber in the hydrodynamic see Cavitation field to intensive removal of non-reactive Layers of the cell wall and contributes to uniform fibrillation of the fiber surface

A fiber suspension of refined to activating sulfite and Sulfafzellulose is conducted at a concentration of 2 to 6% and a temperature of 40 to 50 ⁰ C from the container for return circulation with a pump to the reactor. The return coefficient is 25 to 30. At the point of constriction of the suspension jet, a transverse cylinder creates a hydrodynamic cavitation field that acts on the substance to be treated.

An inclusion reagent is in the form of an inclusion reagent in the suspension through the tube attachments in the confuser introduced a 3% glycerol solution in an amount of 2.0 to 5.0% of the fiber weight.

After the cellulose has been dehydrated, the inclusion reagent is returned to the system via filters and circulates in it.

The treatment of the cellulose in the cavitation field in the medium of an inclusion reagent looks in one "Loosening" their supermolecular structure and increasing the accessibility of the macromolecules of cellulose.

As a result of the treatment wurdefi following ratios achieved, the are compared achievable so far below: Viscosity - 400 centipoise (at 41OcP) at a temperature of 50 ⁰ C, optical density in the 30 mm cuvette 0.7 (at 1.1), filterability - 210 ml (against 55 ml). The cellulose activated with the aid of the system according to the invention was acetylated at 50 ^° C. with acetic anhydride in acetic acid, the catalyst being sulfuric acid. The module of the vat was 20, the amount of catalyst used was 2% of the weight of the cellulose and the ratio between acetic acid and acetic anhydride was 85:15.

When using the system according to the invention, the range of semi-finished products can be used for production of synthetic fibers and films can be expanded by using low quality cellulose.

Example 8

Let us take the example of performing the process of processing pulp for acetylation of cellulose. A fiber suspension of acetylated, comminuted cellulose intended for chemical processing is passed with a concentration of up to 5% and a temperature of 30 to 40 ⁰ C from the recirculation tank with a pump into the reactor transverse cylinder created a hydrodynamic cavitation field that intensifies the acetylation process. The duration of the treatment is 8 to 12 minutes.

The catalyst is introduced into the suspension via the pipe attachments in the confuser

In this way, cellulose can be acetylated, which has not previously been activated.

As a result of the treatment becomes a highly substituted Cellulose triacetate obtained, which has a degree of polymerization of approx. 500, which has reduced the previous acetylation time by 10 to 15 times

Example 9
A suspension of chemical solutions too

■ »Tor» I / - «« i-Ior »Qt« "» Τι. Ήττυ Qr »Jii! FKor« l ^ c »Iri Λ» η »- / ί one

Concentration of up to 8% and a temperature of 30 to 40 ⁰ C from the return container with a

Pump fed into the reactor. At the point of constriction of the suspension jet, a hydrodynamic cavitation field is created through a transverse cylinder, that intensifies the impregnation process. The treatment time is 3 to 5 minutes.

A soaking solution of Cooking acid introduced.

As a result of the treatment, the permeability of the fiber increases, which affects the cooking speed the cellulose has a beneficial effect. The intensified by using the system according to the invention Soaking thus replaces the mercerization process.

Example 10

15th

A fiber suspension made of cellulose to be washed out by chemical reagents is made with a concentration up to 4% and a temperature of 20 to 30 ° C from the return tank with a pump into the Reactor led; .. At the mixing point of the suspension sion beam, a hydrodynamic cavitation field is created by a transverse cylinder the washing process is intensified. The washing time is 10 to 15 minutes.

The washing water is introduced into the suspension via the pipe attachments in the confuser. After the cavitation treatment, the cellulose suspension becomes dehydrated using known methods.

As a result of this treatment, the washing time becomes from 6 to 8 hours in the known methods except for I ^ reduced to 20 minutes The simplicity of the system and operational safety also facilitate the working conditions of the employees.

35

Example 11

A cellulose suspension that is to be subjected to mercerization is loosened in the form of a Mass with a concentration of up to 8% and a temperature of 30 to 40 ° C from the recirculation tank fed into the reactor with a pump. At the point of constriction of the suspension jet a hydrodynamic cavitation field created by a transversely positioned cylinder, the mercerization process stepped up.

Caustic soda is introduced into the suspension through the pipe attachments in the confuser. the Treatment time is 4 to 5 minutes. Under the influence of the cavitation field with high erosion activity become conditions for uniform swelling of the cellulose and complete dissolution created by hemicellulose.

As a result of the treatment, the quality of the finished product is improved and the content of Hemicellulose increased in it Take part in the treatment of cellulose in a caustic soda solution a concentration of 220 g / l and a module of the tank of 20, the hemicellulose content is 28 to 32 g / l in the titer solution and 30 to 35 g / l in the pressed Solution.

Example 12

A suspension of cellulose xanthate to be dissolved is taken from the container for return to the Reactor piped A solvent is introduced into the suspension through the pipe fittings in the confuser Introduced at the aggravation level of the suspension jet a hydrodynamic cavitation field is created by a transverse cylinder, which deep penetration of the solvent into the interior of the polymer and the destruction of the intermolecular bonds stepped up. This accelerates the transition of the xanthate into the solution.

As a result of the treatment, complete dissolution of the cellulose xanthate was achieved within 20 minutes reached. In doing so, it was easy to filter Viscose solution with a viscosity of 50 seconds (according to the ball method) obtained, the solution contained 9.5% Cellulose and 6.7% sodium hydroxide.

Example 13

A fiber suspension of paper pulp to be dyed is made with a concentration of up to 4% The return tank is fed into the reactor with the aid of a pump. Through the arranged in the confusor Pipe sockets are introduced into the suspension of mineral paints. At the point of constriction of the suspension jet, a cylinder is positioned transversely hydrodynamic cavitation field created that the Coloring process of the paper pulp intensified. Dispersion takes place under the influence of the cavitation field of the pigment and the even mixing with the substance to be colored.

As a result of the treatment, the quality and quality of that produced from this paper pulp improve Paper, the aesthetic properties of the product are also significantly improved. In the treatment of suspensions of fibrous materials with the aid of known devices, the cast has a fairly large number visible inclusions of particles with dimensions from 0.08 to 0.4 mm, during the cellulose casting, the treated for a twice shorter duration in the cavitation field of the system according to the invention did not contain any dye inclusions.

Example 14

A fiber suspension of pulp to deflocculating is conducted at a concentration of up to 4% and a temperature of 15 to 20 ^0C from the return circulation tank by means of a pump in the cavitation reactor. A hydrodynamic cavitation field is created at the point of constriction of the suspension jet by means of a transversely positioned cylinder, under the action of which the fiber clumps previously formed in the production process are dispersed.

The fibers of the paper pulp, which are charged in the cavitation field with the potential of the same name, do not form flakes as the suspension continues to move. The paper pulp is up for the casting Paper making machines ready. With five-fold return circulation, the fiber suspension contains around 70 to 80% Less lumps than with the known treatment methods.

Example 15

A suspension of fibrous materials in the form of a waste water stream to be cleaned containing small fibers is fed from the recirculation tank with a pump into the cavitation reactor Via the im Pipe sockets attached to the cone are blown into the sewage air. At the point of constriction of the Suspension jet, a hydrodynamic cavitation field is created by a transverse cylinder, that with the silting process of the wastewater finely dispersed air bubbles intensified under the influence of the pressure impulses that occur when the

Cavitation bubbles arise, the dispersing of the fibers to be flocculated takes place, the supersaturation of the Suspension with air as well as the dispersion of large air bubbles. The intensive stirring of the suspension by the highly tyrbulent current in the cavitation field increases foaming. In the zone of the calm flow, the excreted mass rises in a more finely dispersed manner Air bubbles rise to the surface and entrains fiber particles from the wastewater that are in the wastewater are included. The layer of substances to be flocculated that has risen to the surface is then clarified Separated water

As a result of treating the sewage with acidic, neutral and alkaline agents becomes without Use of any chemical flotation agent increases the concentration of the flotation agent

achieved by up to 5 to 6%. The duration of the Procedure shortened by 2 times

The examples given show that the treatment of pulp suspensions in the hydrodynamic Cavitation field of the plant according to the invention most of the technological processes in the cellulose and Allowed to intensify paper production significantly and also made it possible to use the processes mentioned new equipment and significantly reduced

ίο Cost of manufacturing and operating the systems perform as well as high-quality products with less expenditure on raw materials, energy and time each To establish unity of manufactured production. The simplicity of the system according to the invention allows complete automation of the production process.

For this purpose 2 sheets of drawings

Claims (4)

Patent claims: 1. Plant for processing pulp suspensions in cellulose processing and paper production, consisting of a reactor with a in its housing not far from the reactor inlet in equal distances from its side walls arranged cylindrical element for constriction the suspension flow of fibrous materials, which is carried out with the help of a pump via a pipeline system can be supplied, and for generating cavitation forces in the suspension, characterized in that that a) the cylindrical element (12) is arranged such that its surface line is perpendicular to the direction of flow of the suspension, and
the reactor can be connected on the side of the suspension inlet via a pipeline system to a confuser (13) and on the side of the suspension inlet to a diffuser (14) 2. Installation according to claim 1, characterized in that at the entrance of the confuser along its Circular line pipe attachments (15) for introducing chemical reagents into the suspension stream of Fibers are arranged. 3. Plant according to claim 1, characterized in that the cylindrical surface of the flow around Element (12) is covered with a layer (16) of elastic material. 4. Plant according to claims 1 or 3, characterized in that in the reactor (1) behind the cylindrical umströn ble Zlement (12) along its axis a Vibntor {17) is attached.