FI123427B - Process and reactor for carrying out a reaction between one or more chemicals and a process liquid - Google Patents

Description

METHOD AND REACTOR FOR CARRYING OUT THE REACTION BETWEEN ONE OR MORE CHEMICALS AND PROCESSING FLUID

FIELD OF THE INVENTION The present invention relates to a process and a reactor for carrying out a reaction between one or more chemicals and process fluids. The process and reactor of the invention are preferably adapted to feed and mix in the process fluid stream one or more chemicals which, either alone or in combination with the material carried in one or more process streams, tend to form either organic or inorganic layers, deposits or deposits on the reactor interior. The invention is particularly advantageously suitable for use in the wood processing industry, for example, when one or more chemicals used in the production of pulp and / or paper (including cardboard and tissue) are fed into the production process.

BACKGROUND OF THE INVENTION For example, in papermaking, as in many other industries, there is a need to feed and in-line mix at least one substance, hereinafter referred to as a chemical in the broadest sense of the word, which can individually or chemically, electrochemically or mechanically with one another or with the materials in the flow of the tube, forms solids deposits, precipitates or the like on the wall of the flow tube or channel. It is to be understood, therefore, that in the context of the present invention, the term "chemical" includes gaseous, liquid and solid materials. Otherwise

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That is, said chemical may be, for example, a substance that has reacted chemically previously or is simultaneously processed with a chemical that has been fed or was originally present, or, e.g., a retention or binding agent attached to another solid in the stream.

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00 30 or fed to or with the substance or particle

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£ close. Thus, it is also contemplated that the word 'reaction' encompasses chemical reactions, electrochemical reactions and the attachment of particles by retention agents S and / or binders. In other words, any situation in which o the substance flowing in and / or fed into the process stream forms a material that has a tendency to adhere to the surface or structures of the process tube is called a reaction for clarity. In this embodiment, the word Ίη-line mixing 'refers to mixing that is carried out directly in the process tube, e.g. papermaking, when the chemical is added directly to the filing pulp in the process tube 5 per headbox of the papermaking machine. In-line mixing also encompasses applications in which mixing takes place in the main stream or sub-process liquid or suspension stream without the product resulting from said sub-process being stored in a local warehouse, either alone or in combination with another product.

In some cases described in the prior art, it is sufficient to allow the desired amount of chemical to flow into the tubular stream so that it is mixed with the flowing material, which is a liquid or gas, by the turbulence in the tubular flow itself. Sometimes the desired amount of chemical is calculated at a point in the flow of the tube that has a mechanical device generating turbulence, either a 15 static element, a rotary mixer or e.g. a centrifugal pump, just after the chemical addition point. In some cases, the chemical is fed into a relatively large container or mixing vessel provided in the process, either directly or in combination with, e.g., a substance fed into the container, whereupon a mixer or mixer for mixing the chemical is provided.

In all these contexts, it is possible that either organic or inorganic precipitates affecting the process accumulate on either the wall of a flow tube or a special reactor or on top of another solid structure such as a chemical feeder or mixer / mixer. For example, it has been a disadvantage that organic matter begins to deteriorate and spreads microbes into the stream, in the worst case, the entire end product becomes

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ς wreckage, or that the particles when spilled into larger particles spoil

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^ end product, causing holes in, for example, recycled paper, tissue or ° board (using paper industry as an example) or adverse changes

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^ 30 headbox flows, which changes the quality of the end product. Precipitation can

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a. also completely or partially clog some process equipment or their piping, increase pumping costs, diminish the effect of chemicals, reduce 00 m heat recovery, etc. In addition, a certain type of layer may form the basis for another δ

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3, for example, the calcium carbonate layer significantly increases the precipitation of sodium carbonate in the black liquor evaporators.

Since this problem of various precipitates has been known for as long as industrial processes have existed, numerous efforts have been made to solve it.

One method, of course, is to avoid the use of precipitating materials and to replace them with non-precipitating materials, although this method can only provide relief for a marginal number of problem cases. In some cases, it is not possible to avoid the use of precipitating materials and in some cases, replacement materials are so expensive that it is economically impossible to use them.

Another alternative is to use high quality raw materials starting from the pulp mill bark (taking the pulp and paper industry as an example). In other words, the precipitation problem can be reduced by minimizing the access of the bark layer to the downstream process. It is also possible to reduce the recycling of existing precipitating chemicals by paying more attention to chemicals that cause precipitation problems in the recycling of chemicals. In other words, by taking into account the precipitation problems in each sub-process of the mill, which, for example, using pulp, pulp, and paper, includes at least cooking processes and brown pulp washing and bleaching processes in addition to chemical recovery processes.

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A third alternative is to provide flow conditions in the process such that no precipitate can accumulate e.g. in the flow piping. In other words, the goal is to design the flow piping with as little as possible

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00 30 places where the flow is so calm that it flows with it

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£ solids could settle against the piping surface. This method is also limited because it is virtually impossible to design the flow piping so that no precipitation of S occurs. However, careful planning can extend the washing intervals and the plant downtime required by them.

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A fourth alternative is to take into account the cleaning requirements of the pipeline already at the design stage, thus allowing for a reduction of the required downtime, eg for acid cleaning of process equipment or the like, or even for manual removal of deposits / precipitates.

A fifth way is to fabricate or coat, for example, a flow pipe system or reactor with a material such that materials liable to precipitate cannot adhere to it. However, this has the disadvantage that replacing a conventional steel flow tube or reactor with almost any material will multiply the cost.

A sixth alternative is to use additional chemicals, such as some retention chemicals, chelates, surfactants, or inhibitors, which in one way or another prevent the formation of precipitates. Naturally, however, such chemicals cause at least additional costs because they have to be continuously added to the process fluid. Such chemicals can also cause problems in the treatment of process effluents, water re-usability, or in the final end product, its treatment or recycling.

However, none of the above methods have proven to be fully functional in the pulp and paper industry, but there are major problems with both flow tubes and process equipment, as well as reactors and tanks, when deposits are deposited on their walls.

[013] The above precipitation problems are emphasized when e.g. Injection mixers disclosed in EP-B1-1064427, EP-B1-1219344, FI-B-111868, FI-B-115148 and FI-B-116473 are widely used. The reason for the increased problems is that these injection mixers are capable of mixing chemicals

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00 30 very quickly and uniformly in the process flow, reaction of chemicals or

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The reaction with solids or chemicals in the stream is very rapid. Thus, a large number of chemicals are simultaneously present in the vicinity of the flow tube wall, so that when the chemicals form a solid crystal or particle o there is a high risk that the crystal or particle will adhere to the flow tube wall.

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5 instead of a solid particle such as a fiber or filler particle. Previously, similar chemicals were fed through less efficient agitators, whereby the reaction of the chemicals or the flow with the previously supplied solid or chemical took tens of seconds, sometimes up to minutes, so that deposits on the inner surface of the flow pipe were also distributed over a substantial portion of the flow pipe. Formerly precipitated over the entire length of the process tubes after the feed point, they now, in many cases, cover the surface of the flow pipe a few meters from the chemical feed point. Since it can be assumed that substantially the same amount of reaction products of chemicals will be precipitated on the surface of the flow tube in both conventional mixing and injection mixer 10, it is likely that the deposition layer formed with injection mixers may become significantly thicker than conventional mixing method. At the same time, the risk that the precipitates will break and flow into pieces increases, and the number of problems caused by the pieces may also increase. Such precipitation problems are naturally present both in the wood processing industry and in many other process industries. In fact, in virtually every industry where chemicals fed or mixed in a tube stream are allowed to react with either the material 20 or the chemical that has been fed into the tube filing medium, the precipitation problems described above affect in some way the process progress or intermediate or end product. .

[014] Precipitation problems such as those described occur, for example, in industrial environments in which a wide variety of chemicals, including retention chemicals, binders and / or stabilizers, and the like, are fed and mixed with process fluids.

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In addition to papermaking, these processes in the wood processing industry include mechanical pulp, chemimechanical pulp and microfibres.

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00 30 nanofibre pulp production, washing, bleaching and chemical recovery processes,

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£ which form a large amount of chemical compounds which form precipitates. These can be roughly divided into inorganic and organic compounds.

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Of the inorganic precipitating compounds, in addition to the calcium carbonate briefly mentioned above, the following compounds may be mentioned. Calcium oxalate, the ion of which is formed by the oxygen bleaching of a chemical pulp. Barium sulphate is formed when the bivalent barium cation is removed from the wood material especially during pulping under acidic conditions prior to chemical pulp bleaching. The presence of alum, or aluminum sulfate, increases the precipitation tendency. Sometimes precipitating aluminum hydroxide is formed immediately after feeding the alum. Alum itself is commonly used in papermaking, as in some retention programs, as a resin glue, as a coagulant, etc. these compounds and other compounds and chemicals already present in the fiber suspension or subsequently introduced therein are reacted to prevent precipitation of the new chemicals formed by using various chemicals. Other inorganic compounds which have a tendency to precipitate include e.g. calcium sulfate, calcium silicate, aluminum silicate, aluminum phosphate and magnesium silicates.

Organic precipitates are most often associated with the attachment of various particles to process tubes or other devices and structures associated with the process stream by means of a binder. Among these binders, the following can be mentioned: Resin, which is a wood-based material. In most cases, the resins are fatty acids or resin acids, although some other compounds are traditionally referred to as resins. Sticky materials include glue or adhesive from recycled paper. Mucus is a material formed by microbial activity and is well adapted to the relatively stable high temperatures and relatively constant pH of the paper industry. The fungus may be further mentioned as one binder. All of the above-mentioned precipitating binders are, in a sense, materials fed to the paper produced in the process.

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£ amongst the starting materials, meaning they are not intentionally added to the process. In addition to these, there are chemicals that are added to the process for other reasons, such as antifoam agents, polysiloxanes, mineral oils, retention polymers and chemicals,

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00 30 nanoparticles, microparticles, pH adjusters, gloss additives (OBA, FWA),

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Dispersants, starches, dyes, pigments, waxes, fillers (e.g.

TiO2, CaCO3, talc, kaolin), minerals and adhesives (traditional hydrophobic adhesives: S AKD, ASA, resin and synthetic adhesives) etc. which tend to form precipitates δ

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7 under favorable conditions, either spontaneously or especially in combination with solids or chemicals in the process.

FI-A1-20105231 and FI-A1-20105232 disclose state-of-the-art reactors for mixing chemicals in a process fluid stream such that no or negligible amount of precipitate is formed on the reactor surfaces during the reaction. The Fl publications describe the process of adding at least one chemical to a process fluid in a reactor, mixing the chemical with a process fluid, and reacting with either another chemical or the material in the process fluid itself to form reaction products while simultaneously preventing the chemical (s) from on the surfaces of existing devices.

Preventing the adherence of chemicals or reaction products to the surfaces of the reactor or associated apparatus is accomplished electrochemically. The reactor has a central electrode which extends along the reactor axis along substantially the entire length of the reactor or reaction zone. Throughout the length of the reactor or reaction zone, it is understood the distance (or time) the chemicals fed to react with each other or with the material in the process stream. The surface of the reactor 20 forms a second electrode. In other words, either the reactor is made of an electrically conductive material or the reactor surface is provided with an electrically conductive coating or a plurality of separate electrically conductive strips or the like forming a second electrode. When the electrodes are connected to an electrical circuit, one electrode forms a cathode and the other anode. The existence of an electric current changes the pH of the liquid (water) layer on the electrode surfaces so that the pH near the anode decreases and the pH near the cathode respectively. Practically this

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£ means that when the internal surface of the reactor is an anode and when the electric current is sufficiently high, the pH on the inner surface is so low that e.g. calcium carbonate is not capable of precipitation on the reactor wall. However, the central cathode is attracted

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00 30 carbonate crystals whereby the central electrode is gradually covered with calcium carbonate crystals.

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For this purpose, the electrical circuit is arranged to change the polarity such that, for a given time, the center electrode serves as the anode and the reactor surface electrode acts as the cathode. S Now the pH of the liquid layer near the center electrode drops, resulting in calcium carbonate δ

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8 dissolves from the surface of the electrode into the liquid phase and the surface of the electrode is cleaned. The polarity of the electric circuit can then be changed again.

The reactor described above operates well and keeps both the reactor and the 5 central electrode surfaces clean. However, when using the reactor described above in a full-size paper mill, there have been some drawbacks, even problems.

First, the electric current required to lower the pH to a value sufficiently low for the desired function is greatly enhanced as the reactor diameter increases. This is mainly due to the resistance formed by the thick liquid layer between the electrodes. High electric current means high energy consumption.

Secondly, the high current density also naturally results in a high current density, especially at the center electrode, since its surface area is only a small fraction of the surface area of the other electrode. High current density easily leads to corrosion of the central electrode. Since the corrosion of the central electrode is unacceptable, the current density at the central electrode must be kept at a safe low level of 20.

Third, a solution to both of the above problems could be the use of a smaller reactor diameter. However, a small reactor could mean a significant increase in reactor length to ensure the same reaction time. A long reactor with a central electrode extending over the entire length of the reactor means in practice that, for practical reasons, the central electrode is substantially thin,

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It must be supported at regular, substantially short intervals so that the turbulence of the process fluid stream does not cause the electrode to vibrate and, at worst, to break. This means that the reactor must have a number of support arms,

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00 30 which form a structure in which solid precipitates can accumulate. arms

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£ Cleaning is of course a problem. It is also difficult to arrange a straight reactor, about 10 meters or more in length, sometimes even impossible in practice.

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BRIEF SUMMARY OF THE INVENTION It is an object of the present invention to improve prior art reactor technology by providing a novel reactor that reduces or even completely eliminates at least some of the problems of prior art reactors.

Another object of the present invention is to improve the reactor technology of the prior art by providing a new reactor which reduces the energy consumption of the electrodes used for cleaning the 10 reactors while still allowing the use of large reactor diameters.

It is a further object of the present invention to provide a reactor that operates in a variety of applications in various industries without the risk of formation of precipitation or aggregate layers, which results in degradation of the final product, process problems, production interruptions or extra downtime.

It is a further object of the present invention to provide a reactor that can be connected to a pipeline process, the reactor comprising an efficient chemical mixing system and a reactor cleaning arrangement such that introducing an in-line tubular reactor is considered a good investment or part of the reactor. the length of the reactors.

At least some of the objects of the present invention are achieved by a process for carrying out a reaction between one or more chemicals and a process fluid comprising the steps of:

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^ · Arranging the reactor in a flow tube carrying the process fluid, c) providing the reactor with an internal surface along which the process fluid flows, o '· equipping the reactor with electrochemical means to prevent reaction results

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00 30 precipitation on the inside of the reactor,

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£ · adding at least one chemical to the process fluid in the reactor, ^ · mixing said at least one chemical into the process fluid,

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• reacting said chemical with either another chemical or with the material in the process fluid itself to form reaction products, • preventing the deposition of either the chemical or reaction products on the surfaces of reactor 5 or associated equipment, • wherein: preventing the precipitation by providing an electric field volume very close to the inner surface of the reactor.

At least some of the objects of the present invention are achieved by a reactor for carrying out a reaction between one or more chemicals and process fluid, which is disposed within a flow tube carrying the process fluid, the reactor having an inner surface along which the process fluid flows; electrode, to prevent electrochemical precipitation of the reaction results 15 on the inner surface of the reactor, which outer electrode is arranged on the inner surface of the reactor, wherein the inner electrode is arranged very close to the inner surface of the reactor.

Other typical features of the process and reactor of the present invention will be apparent from the appended claims and the following description, which show the most preferred embodiments of the invention.

By using the present invention, e.g. the following advantages when the length of the reactor of the invention is dimensioned to substantially correspond to the mixing that occurs in the pipe flow or any precipitation zone that has previously caused some contamination of the surface of the flow pipe.

• no precipitate is formed or adheres to the δ surface of the flow pipe to degrade or affect the end product or its quality

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^ production, cp ^ · washing of pipes to eliminate precipitation can be avoided,

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30 · use of various additional chemicals can be either completely avoided or significantly reduced, · short reaction zone - the reactor can be positioned up to a short section of the flow line between different process steps, · good control of the reactor and process runnability, 11 • easy control by reporting; use allows for a variety of alarms, greatly facilitating quality control, • faster and more aggressive reactive chemicals can be used, 5 because rapid and efficient mixing ensures a consistent mixing result and reactor cleaning arrangement ensures that reactor walls remain clean, and having faster reactions because it is possible to use shorter reactors with faster reacting chemicals 10, which facilitates the installation of the reactor into the process piping system I.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, the process and reactor of the present invention and its operation will be described in more detail with reference to the accompanying schematic drawings, in which:

Figure 1 schematically illustrates a prior art reactor having a central electrode; Figure 2 schematically shows a reactor according to a preferred embodiment of the present invention,

Figure 3 shows in more detail a preferred embodiment of an inner electrode according to the present invention,

Figure 4 is a cross-sectional view of a reactor according to another preferred embodiment of the present invention,

Figure 5 shows a third preferred embodiment of the present invention

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Fig. 6 shows a reactor according to a fourth preferred embodiment of the present invention, and

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Figure 7 shows a fifth preferred embodiment of the present invention

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Fig. 8 shows the change of pH as a function of time over carbon dioxide and

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Calcium carbonate is prepared from lime milk in the o reactor of the present invention.

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DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows, relatively schematically, a reactor 10 according to prior art 5, which is described in FI-A1-20105231 and FI-A1-20105232. The reactor 10 of Figure 1 comprises a straight cylindrical flow tube 12 into which an electrically conductive electrode rod 16 is centrally attached to the flow tube 12 by means of arms 14. The rod is electrically connected via a single arm 14 'to the control system 18, which preferably has a voltage source. The electrode rod 16 should be electrically insulated from the flow tube 12 in case the flow tube 12 is made of metal as it is in most cases. The isolation can be accomplished, for example, by arranging the rods 14 and 14 'fixing rods 14 and 14' of non-conductive material, or by making the rod 16 essentially non-conductive and coating the appropriate portions thereof with the conductive material 15. A second electrode 20 is disposed on the inner surface of the flow tube 12. Said second electrode 20 is electrically connected to a voltage source / control system 18 similar to the first so that the desired voltage difference can be provided between the inner surface of the flow tube 12 and the electrode rod 16 located in the middle of the tube. Of course, the simplest solution 20 is that the flow tube 12 is made of metal, whereby it can function as a complete electrode 20 without the need for a separate electrode. When the flow tube 12 is made of non-conductive material, there are a few of said second electrodes 20, which are preferably spaced evenly along the circumference of the tube 12 and the longitudinal direction of the reactor 10. Another alternative is to coat the flow tube 25 from the inside with an electrically conductive material, wherein said coating acts as an electrode 20.

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Voltage source / control system 18 preferably, but not necessarily, comprises some kind of measuring sensor 22 which monitors e.g. mixing efficiency and / or

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^ 30 reaction progress in reactor 10. This sensor may be based e.g. on tomography

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£ (here the tomographic measurement is preferably based on the electrical conductivity of the fiber suspension, i.e. mainly water, g), but it may equally well measure the pH of the pulp or the electrical conductivity of S. The purpose of the measuring probe is to monitor the efficiency of mixing, the progress of the reaction and / or the purity of the reactor surface such that e.g.

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The supply pressure or flow rate can be adjusted as required. If necessary, said measuring sensor and a second measuring sensor in addition to said sensor may be arranged in connection with the electrode rod 16, whereby it is possible to monitor, for example, reaction progress, in addition to the reactor surface, in the middle of the flow. If necessary, the measuring transducer 5 can be arranged to be located at a distance from the actual electrode rod, e.g. It should further be noted that the progress of the reaction or reactor purity can also be monitored by machine vision based methods or devices that record the process flow or reactor wall temperature in an appropriate manner such as conventional thermometers, temperature sensors or a thermal camera.

The prior art reactor further comprises a device 24 for feeding chemicals. The purpose of the feeder 24 in this case is to both feed 15 and mix a number of chemicals into the process stream. This is accomplished by injecting one or more chemicals substantially perpendicular to the process fluid flow direction (in a direction perpendicular to the process fluid flow direction +/- 30 degrees) and at a high injection rate relative to the process fluid flow rate. Preferably 3 to 20 times the process fluid flow rate. If the chemical is fast reacting, the uniformity of mixing is completely dependent on the operation of the feeders. In addition, the highly variable amounts of chemicals to be fed place great demands on the feeder. For example, in the wood processing industry, when calcium-containing lime is fed to the papermaking machine headbox for pulping calcium carbonate as a filler, it is often necessary to supply enough lime milk to have a calcium content in the pulp of the order of

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£> 1 g / l. If the crystallization reaction of calcium carbonate is induced in a smaller volume of liquid, such as in the pulp component, the calcium content in the pulp component (as well as the actual amount of calcium) is naturally

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00 30 higher, sometimes several times the above value. In this description, the term

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£ 'process fluid' means primary pulp suspension (long fiber pulp, short fiber pulp, mechanical pulp, chemimechanical pulp, chemical S pulp, etc.), recycled pulp suspension (recycled pulp, wreckage, reject, o fiber fraction from fiber recovery filter,

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14, a filtrate from a fiber recovery filter, or a combination thereof. In the prior art Figure 1, the wall of the flow tube has at least one injection mixer 24, preferably a TrumpJet® injection mixer developed and sold by Wetend Technologies Oy, which allows one of the components of calcium carbonate production 5, carbon dioxide and / or lime, to mass. A typical feature of one version of the injection mixer 24 is that the carbon dioxide and lime milk is fed and mixed with the feed liquid such that the chemical is contacted substantially simultaneously with the feed liquid when the mixture is injected into the pulp. When using an injection mixer, the amount of carbon dioxide and lime milk can vary greatly with the amount of feed fluid, allowing relatively large amounts of feed fluid to be used, ensuring that the amount of chemicals, in some cases a very small amount, penetrates deep into the mix. Preferably, the amounts of carbon dioxide and lime milk fed are preferably stoichiometric such that substantially all of the chemicals in the reactor react and no trace of any chemical remains in the pulp. A typical feature of another version of the injection mixer is that at least one chemical to be mixed and the feed liquid are fed to each other and, if necessary, mixed with one another prior to the actual feeder.

The prior art cleaning arrangement of reactor wall 12 shown in Figure 1 to dissolve existing calcium carbonate precipitates and prevent the formation of new calcium carbonate precipitates operates by directing the DC voltage to the electrode rod 16 and the reactor wall 12 via the power supply / control system 18. such that the electrode rod 16 acts as the cathode and the reactor wall 12 acts as the anode. When

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The wall 12 is the anode, the pH of the liquid adjacent to the wall 12 is clearly decreasing

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to an acidic region, less than 6, preferably less than 5, most preferably between 2 and 3, whereby the carbonate is not attached to the wall 12. In fact, carbonate crystals

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00 30 cannot even come into contact with the wall because they dissolve in the liquid phase

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£ at low pH. Naturally, the carbonate tends to precipitate on the surface of the cathode electrode rod when the pH is high near said surface.

S The disadvantages of said precipitation tendency are easily eliminated by programming the voltage source / control system 18 to change the system

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15 polarities, whereby the carbonate precipitated on the surface of the former cathode is rapidly dissolved in the acidic liquid formed near the electrode now functioning as the anode. The simplest control method is to program the control system to change the polarity at regular intervals (from fractions of a second to 5 minutes or hours) to keep both electrodes clean. Another way to control polarity changes is to use the control pulse from the process. For example, it is possible to monitor the voltage change between the cathode and the anode, whereby a certain voltage increase practically means a layer of precipitation of a certain thickness (the layer acting as an insulation). Thus, the control system can be calibrated 10 to change the polarity of the system by a given potential difference. Similarly, when said potential difference is reduced back to its original level or when the potential difference no longer changes, the control system changes the polarity back to its original state.

The above-described prior art purification system is naturally useful, in addition to the exemplary application of calcium carbonate for the papermaking industry, in all applications in the process industry where the formation of precipitates is dependent on the pH of the liquid. According to the previous example, the cleaning arrangement of the invention 20 can be used to adjust the pH of a liquid near the process tube wall or structures mounted inside the tube so that no precipitate can adhere to them.

However, as previously mentioned, the prior art purification arrangement has serious problems if the reactor diameter is increased. In practice, a cleaning system according to prior art

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£ works well when the reactor diameter is in the order of a few tens of centimeters, but as it grows to about a meter or more, energy consumption increases and the corrosion problems of the central electrode increase to such an extent that the prior art

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The use of a cleaning system according to 00 30 should be carefully considered.

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The purification arrangement S according to the present invention, schematically shown in Fig. 2, provides a solution in which the reactor diameter has no negative effect on the operation of the purification arrangement. In accordance with the present invention

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The reactor 30 has a flow tube 12 similar to that of the prior art reactor shown in Figure 1, with the flow tube serving as a reactor jacket having, if desired, end flanges 26 and 28 at opposite ends of the reactor 30. The reactor jacket, i.e. the flow tube 12 or its inner surface coating or separately attached elements 5, serves as the outer electrode 20 of the purification arrangement. The inner electrode 32 is arranged very close to the outer electrode 20 in accordance with the present invention. unobstructed through its interior. The inner electrode 32 is supported on the inner surface of the flow tube 12, i.e. the reactor jacket, by the feet 10 34. The number of legs 34 will naturally depend on the length of the reactor, its diameter and the stiffness of the inner electrode 32. Preferably, there are at least two sets of legs 34 disposed at or near the ends of the inner electrode 32. Each leg set is preferably, but not necessarily, arranged in its own circumference around the inner electrode. Preferably, there are at least three legs 34 in each set of legs arranged at regular intervals around the inner electrode 32. According to this embodiment, the inner electrode is made of a steel tube having a thickness of 3 to 15 mm, a hole diameter of the order of 5 to 20 mm and a distance from the inner wall of the reactor of 5 to 50 mm. It should be understood, however, that the dimensions given cannot be considered as critical, but are merely exemplary 20 since, for example, the type of pulp (mechanical, chemical, recycled, wreck, etc.) and / or pulp consistency can influence the dimensions as well as the electric current used.

The control system and its voltage source 18 are connected by wire 36 to the outer electrode 20, by wire 38 to the inner electrode and by wire 40 to an optional sensor 22.

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The cleaning arrangement operates as shown in connection with Figure 1. In other words, and when taking calcium carbonate deposition only

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As an example, calcium carbonate deposition is prevented by electrochemical

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£ method. The basic principle of the electrochemical process is to lower the pH electrochemically near the reactor surface by electrolyzing water, i.e. by saturating S with that part of the process fluid by protons. In water (water is the major component in the vast majority of process fluids to which the invention is applied), the C117 reduction reaction occurs in a negatively charged cathode when electrons are e-released from the cathode to hydrogen cations to form hydrogen gas (acid-balanced half reaction).

5 Anode (oxidation): 2 H 2 O (I) -> 02 (g) + 4 H + (aq) + 4 e '(1)

Cathode (reduction): 2 H + (aq) + 2 e -> H2 (g) (2) The standard potential of the water electrolysis cell is -1.23 V at 25 ° C. It is possible to locally lower the pH to less than 10 of the calcium carbonate precipitate, i.e. near the anode surface, by increasing the concentration of hydrogen ions (see equation 1). The principle is to use an electric current of sufficient strength, which results in the concentration of hydrogen ions near the inner surface of the flow tube, i.e. the reactor, by installing an inner electrode (cathode) around this inner surface.

Naturally, the inner electrode, i.e. the cathode, tends to accumulate carbonate ions on its surface, whereupon the polarity of the electrodes has to be changed from time to time. This is also explained in detail in connection with Figure 1. Due to the fact that the electric field is located practically inside the reactor and a tubular inner surface of the outer electrode surface, the change in polarity does not change the conditions of the inner electrode 20 inside of the surface, unless special measures are taken. In fact, if the inner electrode has a solid surface, the inner surface of the electrode will allow the calcium carbonate to deposit on its surface as if there was no electrochemical cleaning arrangement.

Injection mixer 24 may contain process fluid itself, process fluid solids fluid, filler fraction

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£ or fiber suspension is used as feed fluid. In other words, in addition to pure water, raw water or a cloudy, clear or super clear filtrate from the process, the liquid used may also be, for example, a suspension of

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00 30 abundant solids. One option worth considering is the mass itself

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£ Using one of its fiber or filler components as a feed liquid. When using pulp, this can be accomplished, for example, by taking a side stream S from the flow tube 12, which in this embodiment is pulp, and then o feeding it into the injection mixer 24 by means of a pump.

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Another essential feature of the injection mixer 24 is that the velocity of the jet of liquid feed and carbon dioxide or lime milk is substantially higher than the velocity of the pulp flowing in the flow tube. Thus, the chemical and feed fluid jet 5 penetrates deeply into the process fluid stream and mixes it effectively.

The ratio of flow rates may range from 2 to 20, preferably from 3 to 12. Advantageously, but not necessarily, it is possible to fabricate the reactor 30 according to the invention with all ducts, piping, pumps and purifiers within the piping within the lengths defined by flanges 26 and 28, the installation of the reactor 30 10 in the pipeline can of course be carried out as easily as possible. An essential structural solution for the operation of the reactor is to place both the electrode rod and at least one electrode on the circumference of the flow pipe so that their effect extends both to the distance upstream of the reaction zone and to the length of the reaction zone. This dimensioning rule is also applicable when the chemical itself tends to adhere to the wall of the process tube or the structures in the process tube. Also in this case, the electrode rod should extend at least a distance from the supply of the chemical in which the chemical has already been used up.

The number of injection mixers used to supply one chemical or chemical compound in a reactor is mainly dependent on the diameter of the reactor or flow tube. When using standard size Wetend Technologies Oy TrumpJet® Injection Mixers, 1 to 6 are required, depending on the diameter of the flow tube.

Figure 2 shows a situation in which carbon dioxide or lime milk is fed

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From the injection mixer 24 within the reactor 30 to the right filing mass such that the jet of jet penetrates almost instantaneously over substantially the entire cross-section of the reactor / flow tube. Because the injection is by injection

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00 30 nozzle designed for this purpose, the chemical stream has been removed

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£ mainly in such small drops or bubbles (when gaseous carbon dioxide is fed) that carbon dioxide or lime milk is mixed very quickly, virtually immediately. At the same time, both reactive chemicals o and react with or otherwise interact with the chemical

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The pulp components come into contact with one another substantially immediately after injection mixing. In other words, an efficient injection mixing ensures that the time required for the transfer of material before the reaction is minimal compared to conventional mixing methods.

Figure 3 shows in more detail the structure of an inner electrode according to a first preferred embodiment of the present invention, which provides a solution to the above problem. In other words, the inner electrode 32 consists of a tube having a series of legs 34 at least at both ends thereof.

Preferably, the tube is made of an electrically conductive material, for example metal. However, it may also be coated with a conductive layer. The tube is perforated so that the electric field is able to reach the inside of the inner electrode 32 and, when the electrode acts as an anode, lower the pH to affect the solubility of the calcium carbonate in the liquid phase. In the embodiment of Figure 3, the openings 36 in the inner electrode 15 32 are circular. The apertures 36 are preferably arranged in such a pattern that the heel areas 38 between the apertures are minimized. It has been found that the wider the base areas 38 between the apertures 36 on the inner surface 40 of the electrode, the greater the risk that the calcium carbonate will permanently deposit in those areas. To minimize this risk, the apertures 36 may optionally be made conical 20 so that the conical apertures taper outwardly so that the heel areas 38 on the inner surface 40 of the inner electrode 32 are smaller than the standard holes of constant diameter.

When the test reactor for the production of PCC was provided with the electrochemical purification arrangement 25 according to the invention, that is, 6 mm away from the inner electrode 32 arranged at the outer electrode 20 of the reactor 30, the reactor 30

C/O

£ The inner surface remained clean throughout the duration of the test runs. Also, all surfaces of the inner electrode 32 remained clean after minimizing the shape of the base regions by making the openings of the inner electrode tapered. In other words

C/O

00 30 the cleaning arrangement was able to completely prevent the formation of precipitates as well

X

£ on the reactor surface and on the inner electrode surfaces. Another thing that was discovered during the experiments performed was that lignin acts in contrast to S calcium carbonate. In other words, lignin precipitates at low pH. This means that when carbonate deposits are dissolved at low pH, lignin

CVJ

20 kind of replaces calcium deposits. Now, as the polarity of the electrodes is changed, the pH rises, whereby the lignin dissolves and calcium carbonate begins to precipitate on the electrode surface.

A further method of reducing the size of the base regions on the inner surface of the inner electrode is to make the apertures triangular, or rectangular or hexagonal, or in fact have any shape in which the base regions may be rod-shaped, i.e. flat. Figure 4 is a schematic cross-sectional view of a reactor 30 according to another preferred embodiment 10 of the present invention. The flow tube 12, i.e. the reactor jacket, supports the inner electrode 32 by the feet 34. With the base width 38 between the tapering apertures 36 in the inner electrode 32 having the same width, it is easy to make the entire cross-section of the base regions 38 generally triangular (meaning the base B of generally triangular shape 15 faces the outer electrode 20 and tip T is substantially ie, generally, the sides of the triangular shape need not have any particular shape, but may be planar, curved, or even consist of two or more planar or curved portions) such that the base regions 38 have no flat surface on the inner surface 20 of the inner electrode 32. only line at tip T. Experiments carried out show that the side surfaces S of the apertures (i.e. also the side surfaces of the heel regions) are clearly within the electric field, that is, in an area where the pH changes sufficiently to prevent permanent carbonate precipitation.

[051] According to a third preferred embodiment of the present invention shown in Figure 5, the inner electrode 32 consists of bars 42 which

C/O

£ extend parallel to each other in the desired direction. An obvious alternative is to arrange the rods to extend in the longitudinal direction of the reactor 30, i.e. in the flow direction of the process fluid. However, if it is desired that the process fluid proceeds helically

C/O

In the reactor 30, the rods 42 may be arranged in any desired angular position

X

£ relative to the axial direction. The bars 42 are preferably triangular in cross-section with the base B of the triangle facing the inner wall of the reactor, whereby the tip T of the triangle is toward the inside of the inner electrode 32 to form an imaginary inner surface 40 'of the inner electrode 32. An inner member of the rods 42

CVJ

The configuration of the electrode 32 requires that the bars 42 be arranged substantially parallel to each other to form a tubular body such that the distance between the bars 42 is substantially the same over the entire length of the electrode 32. This may be accomplished by arranging small spacers (not shown 5) of equal size between the rods or by attaching the rods B from their sockets to at least one pair of circular rings 44. Supporting electrode 32 to the inner surface of the reactor with legs 34 similar to FIG. spacers or circular rings 44, or at least the same circumference as the spacers.

In the above embodiments, it has been assumed that the reactor is a cylindrical vessel of substantially the same diameter as the process flow tube in which the reactor is mounted.

According to a fourth preferred embodiment of the present invention, the reactor 30 is cylindrical but has a larger diameter compared to the process flow pipe 50 to which it is attached. In fact, such a structure would not have been possible without the present invention, which allows the use of such large diameters as is otherwise applicable since the purification arrangement of the reactor 20 does not place any limits on the diameter of the reactor. Of course, it will be appreciated that the reactor 30 of this embodiment may utilize any type of inner electrode 32 of the present invention.

According to a fifth preferred embodiment of the present invention, the reactor 30 is conical so that its diameter increases in the direction of flow of the process fluid. In this case, it is also possible to use anything

C/O

The type of inner electrode according to the present invention. However, the inner electrodes made of rods provide a viable alternative, since the design allows the distance between the rods to increase

C/O

00 30 downstream if desired. It is also possible to use rods with

X

The cross-sectional shape changes along the length of the rod, whereby the widths of the bars (preferably triangular) facing the inner wall of the reactor increase to meet the growing circumference of the conical inner electrode S such that adjacent δ

CVJ

22 the gap between the bars remains constant. In this case, the main cone angle of the rod also changes.

As regards the use of the reactor of the present invention in practice, it can be applied to any position in any industry which has a risk of precipitation of solid material on the reactor surface which is soluble by changing the pH of the liquid. The chemicals involved can thus be fed in any way. However, the use of injection mixers is a viable option. Figure 2 schematically illustrates the use of one injection mixer or one set of 10 injection mixers (or stations) arranged in the same reactor circumference. Figure 7 shows a reactor having two injection mixers or mixer stations (a set of mixers mixing the same chemical on substantially the same reactor ring) 24 'and 24' on the same reactor ring. By means of said mixers 24 'and 24', it is possible, by way of example only, to ensure the supply and mixing of carbon dioxide and lime milk 15, as described above, into the filing pulp much more efficiently, faster and more uniformly than before.

The reactor of Fig. 7, i.e. having two different injection mixer / injection mixer stations 24 'and 24 "in the same or substantially the same circumference of the 20 reactors, is used in-line production of PCC, for example by feeding and mixing carbon dioxide injection mixer 24 'or mixer set 24' and lime milk is fed from another injection mixer 24 'or mixer set 24'. It is also possible to position said mixer (s) or mixer stations on two different circumferences of the flow pipe whereby the supply of chemicals and the mixing are performed sequentially. The feed of said chemicals can be arranged in any order, i.e. first the milk of lime (Ca (OH) 2) and then

C/O

ς carbon dioxide (C02) or vice versa. Our tests have found that without any

CM

^ the PCC layer noticeable in the cleaning or anti-fouling system attaches very rapidly to the wall of the flow pipe leading to the headbox, i.e. the reactor 10

C/O

^ 30 causing the above problems.

X

cc 0- For example, the precipitation of calcium carbonate S used as a filler in papermaking can thus be carried out by the in-line process o directly in the process tube leading to the headbox of the papermaking machine. Over here

CM

In the reactor used for this purpose, injection mixers are preferably needed to supply both carbon dioxide and lime milk. Of course, it is also possible for one of the chemicals to be fed into the pulp already in the previous step, possibly even using another type of mixer. In this case, however, injection mixing of the chemical introduced at least later allows the crystallization of PCC, i.e. precipitated calcium carbonate, to occur within a very short distance in the process tube. In other words, with reference to Figure 2 and assuming that one of the chemicals (Ca (OH) 2 and CO 2) has already been fed and mixed into the pulp before reactor 30, or with reference to Figure 7 and assuming carbon dioxide and lime milk 10 are first fed from mixer 24 '. , and then carbon dioxide or lime milk from the mixer 24 ", the actual crystallization reaction of the PCC can, in practice, begin immediately after the introduction of the latter chemical.

The graph of Fig. 8 shows the change in pulp pH (vertical axis) as a function of 15 (horizontal axis, in seconds) as calcium carbonate is precipitated into the pulp with the reactor shown in Fig. 7. In the crystallization process shown schematically in the figure, carbon dioxide is first introduced into the pulp (at the origin of the axes), whereby the pH of the pulp slightly decreases from the normal pH of 7.5, depending on the amount of carbon dioxide injected and time. Immediately after the start of lime milk feeding and mixing, the pH of the pulp begins to rise and in practice reaches its maximum value in the range of 11-12, from where it rapidly returns to about 7.5 as soon as the chemicals are used up in the crystallization reaction. In the tests, chemicals fed in stoichiometric relation to each other consumed in less than two 25 seconds, or about one and a half seconds. A prerequisite for such a rapid crystallization reaction is that the mixing of the kernal (s) is substantially

C/O

g perfect using properly executed injection mixing (at least for the chemical fed to the latter, preferably both) and the Ca 2+ and CO 32 'ions formed in the mass quickly find each other and react

C/O

00 30 to form calcium carbonate crystals. Because of the very short overall duration of the reaction

X

The size distribution of the carbonate crystals formed is very uniform. According to some estimates, it is typical of such a PCC production reaction, as already mentioned above in S, that immediately after the crystallization reaction, the carbonate crystals o are in such a stage, i.e. in an unstable crystalline form

CVJ

24 calcite that they tend to adhere to virtually any suitable solid particle or nearby surface. In the pulp, these particles include fibers, various fine solid particles, filler particles, and other carbonate crystals. Of course, the walls of the flow pipe and other objects and structures in the flow pipe, such as the nozzles of the feed and mixing devices and the like, are also a good base for adhering carbonate crystals, whereupon deposits are formed on the surface of the flow pipe. In other words, carbonate precipitates are formed on the walls of the flow pipe and other structures only during the unstable crystalline form step, whereby the flow pipe can be practically completely clean by preventing the unstable carbonate from precipitating on the surface of the flow pipe.

The above-mentioned strong pH change as carbon dioxide and lime milk is fed as the crystallization reaction proceeds, and in particular at the end of the crystallization reaction, provides the ability to monitor the progress of the reaction via sensors measuring the above pH. If the sensor 22 is positioned as shown in Figure 2 at the level of one end of the electrode, i.e. the level of the reactor end, the pH measured by the sensor 22 should be of the same order as before the first chemical is applied to avoid additional deposits on the tube. Thus, if the pH value measured by the 20 sensors placed is significantly higher, the feed / mixing parameters of the chemicals should be changed to improve the mixing efficiency of the chemicals. Of course, there may be a plurality of such pH sensors along the length of the reactor (either on the wall of the reactor or on the inner electrode, or both), whereby the change in pH provides a clear picture of the progress of the crystallization reaction.

[060] With reference to the above example, one is worth mentioning

C/O

The solution is one in which the sensor measuring the pH of the suspension entering the reactor reaction zone is located upstream of the reactor, whereby the control system receives up-to-date information on the pH of the suspension entering the reactor. Self

C/O

00 30 such a sensor should be located first upstream of the chemical introduced

X

£ to find out the pH of the fiber suspension without chemicals. By keeping the ratio of carbon dioxide to S lime milk fed to the reactor after this sensor by supplying chemicals 5 under the control of flow measurement, it is possible to monitor carbonate

CVJ

25 crystallization reaction by means of arranged pH sensors. Similarly, it is possible to ensure at the end of the reactor that the crystallization reaction is complete. This is easily verified by comparing the pH value at the end of the reactor with that measured before the reactor. If the values are the same, the chemicals as a whole have reacted and there is no longer a risk that carbonate will precipitate on the surface of the pipe or on the structures inside it.

Similar monitoring of reactor operation can also be achieved using tomography. A noteworthy method of monitoring the progress of the reaction is further a measurement based on a temperature gradient in which, for example, thermometers or temperature sensors in the process tube are used to measure or monitor the temperature of the process fluid, where the reaction step is detected. Another possible way is to photograph the reaction with a thermal camera, whereby the reaction can be distinguished from the background when it is endothermic or exothermic.

The crystalline formation described above, the precipitation of chemicals, or the attachment of the corresponding reaction results, or the chemicals derived from the precipitation itself by chemical reactions, to the reactor walls or to the structures of its process equipment, also occur as a result of a surface chemistry phenomenon. in the paper, pulp and cellulose industries, when anionic waste, extracts (pitch), oxalates, calcium, etc., carried in the pulp stream are precipitated in the reactor.

In addition, reaction chemicals such as various aluminum derivatives (aluminate, alum) also cause troublesome precipitates by their own modes of operation.

Similarly, various adhesives such as AKD, ASA, resins and synthetic adhesives such as

C/O

^ SMA, cause precipitation in suitable applications.

c \ j i C \ l? Similar solutions can be found, for example, in cellulose

C/O

00 30 in pulp mills for the processing of waste solutions, black liquor and white liquor,

X

£ for the production of various by-products of the pulp mill (biodiesel, etc.), "t chemical feed for the bleaching plant, DIP processes S for the pulp mill, etc.

δ

CM

Finally, it should be noted that only some of the most preferred embodiments are described above. Thus, it is clear that the invention is not limited to the above embodiments, but can be applied in many ways within the scope defined by the appended claims. It should be understood, of course, that in the foregoing, the wood-processing industry and the treatment of pulp or stock in various embodiments have been used by way of example only. Thus, the process and reactor of the invention can be used in any process in which various precipitates tend to accumulate in the process tube system and in which the precipitates or deposits can be removed by dissolving them at low pH. The features disclosed in connection with various embodiments of the present invention may also be used in connection with other embodiments within the scope of the invention and / or different configurations of the features disclosed may be combined if desired and technically feasible.

15

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't co

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Claims (20)

A process for carrying out a reaction between one or more chemicals and a process fluid comprising the steps of: a. Arranging a reactor into a flow tube (12) for transporting the process fluid; b. Providing the reactor with an internal surface along which the process fluid flows; c. equipping the reactor with electrochemical means to prevent precipitation of reaction results on the inner surface of the reactor, d. adding at least one chemical to the process fluid in the reactor (30); e. mixing said at least one chemical in the process fluid; f. reacting said chemical with either another chemical or material in the process fluid itself, to form reaction products, g. preventing the deposition of either the chemical (s) or reaction products on the surfaces of the reactor (10) 15 or associated devices, characterized in that h. the precipitation inhibition is accomplished by providing an electric field for a substantially small portion of the reactor volume 2. Förfarande enligt patentkravet 1, kännetecknat av att det electriska fältet anordnas alldeles intill reactor inre yta med hjälp av ond fränder reactor inre yta anordnad rörformig inre electrode. 25 Method according to Claim 1, characterized in that an electric field is provided very close to the inner surface of the reactor at a distance from the inner surface of the reactor by means of a tubular inner electrode. 3. Förfarande enligt patentkravet 2, transducer av att utfällningen Päden inre co g electrode förebyggs genome att perforera electroden och därigenom underlätta ^ ätkomsten av electriska fältet in i den inre electrode. C \ 1 cp CO ^ 30 4. Förfarande enligt patentkravet 2 eller 3, rotation technique av x den perre electrodes X £ perforated at att den inre electrode inre areal minimer. c/o Method according to claim 2, characterized in that deposition on the inner electrode is prevented by tearing the electrode and thereby facilitating the access of the electric field to the inner electrode. A method according to claim 2 or 3, characterized in that the inner electrode CVJ is torn so that the inner surface CO 00 30 of the inner electrode is minimized. X cc CL The reactor (10) and the reactor (10) and the reactor (12) som C \ J transporter and the processor, slow the process electrodes, and the electrodes for the electrode, dvs. en radiellt sett inre och yttre electrode för att electrochemistry förebygga utfällningen av reactorsprodukterna main reactor inre yta, reactor yttre electrodes in the reactor end of the electrode, anordnad alldeles intill reactors (10) inre yta. A reactor for carrying out a reaction between one or more chemicals and process fluid S, which reactor (10) is disposed within a flow tube (12) for transporting process fluid o and having a reactor inner surface along which the process fluid flows, and radially inward and outward electrode, to prevent electrochemical precipitation of the reaction results on the inner surface of the reactor, which outer electrode is arranged on the inner surface of the reactor, characterized in that the inner electrode is arranged very close to the inner surface of the reactor (10). 5 6. The reactor is patent patent 5, the bending path of the electrode (32) 10 insida is transformed into an electrode (32). 6. The reactor according to claim 5, characterized in that the inner electrode has a tubular shape to permit flow of the process fluid electrode (32) through the interior. 7. Reactor enligt patentkravet 6, a rotary tube for att att den inre electrode and försedd med öppningar med upphöjningsomräden jam. Reactor according to Claim 6, characterized in that the inner electrode has openings with basal areas between them. 8. The reactor enligt patentkravet 7, the rotating screws of the att attöppningarna and the canister som minimerar upphöjningsomrädena mellan öppningarna. Reactor according to Claim 7, characterized in that the openings are arranged in a pattern which minimizes the heel areas between the openings. 15 9. Reactor enligt patentkravet 7 eller 8, with rotunda, triangular, rectangular eller sexhörn. 20 Reactor according to claim 7 or 8, characterized in that the openings are circular, triangular, rectangular, hexagonal. 10. The reactor is equipped with patent screws 7, 8, or 9, with rotating screws at the electrodes. Reactor according to Claim 7, 8 or 9, characterized in that the apertures 20 converge towards the outer electrode. 11. Reactor enligt face av föregäende patent krav 7-10, kännetecknad av att 25 upphöjningsomrädena har i regel en triangular form, där triangelformens bas om mot den yttre electrode. CO δ (M ^ 12. Reactor enligt patent dowel 5, rotary terminals avert den in electrode terminals.). 50 mm .CO LO δ C \ l A reactor according to any one of claims 7 to 10, characterized in that the base regions are generally triangular in shape with the base of the triangular shape facing the outer electrode. 25 A reactor according to claim 5, characterized in that the inner electrode COg is arranged at a distance from the outer electrode. c \ j i CVJ A reactor according to claim 12, characterized in that the distance between the electrodes CO 00 30 is 5 to 50 mm. CC CL 14. A reactor enligt patent cravet 5, 12 eller 13, a turn-off valve for the use of an electrode uterus or a strainer for the connection to the stock. Reactor according to Claim 5, 12 or 13, characterized in that the inner S electrode consists of rods which are mounted side by side at a distance o from each other. CVJ 15. The reactor enligt patent kravet 14, the rotating tongs av att stängerna har i regel to 5 triangular torsion rods. Reactor according to Claim 14, characterized in that the bars are generally triangular in cross-section. 16. The reactor enligt face av föregäende patent krav 5-15, the bending jets av att den inre electrode and med fötter head reactor inre yta. Reactor according to one of the preceding claims 5 to 15, characterized in that the inner electrode is supported by feet on the inner surface of the reactor. 17. Reactor enligt face av föregäende patent application no. 5-16, turn-off reactor har en diameter som and större än diametern av processröret, vid flashing reactor. A reactor according to any one of claims 5 to 16, characterized in that the reactor diameter is larger than the diameter of the process tube to which the reactor 10 is attached. 18. Reactor enligt face av föregäende patent krav 5-17, kännetecknad av att 15 reactor har en diameter som ekar i processvätskans flödesriktning. A reactor according to any one of claims 5 to 17, characterized in that the reactor has a diameter which increases in the direction of flow of the process liquid. 19. Reactor enligt face av föregäende patent krav 5-18, kännetecknad av att reactor tower försedd med en mätanordning (22), företrädesvis en tomografisk givare, en givare som mäter pH standard eller en givare som mäter elledningsförmägan. 20 Reactor according to one of the preceding claims 5 to 18, characterized in that the reactor comprises a measuring device (22), preferably a tomographic sensor, a pH meter sensor or a conductivity sensor. A reactor according to any one of claims 5 to 18, characterized in that the reactor (10) has a measuring device which is a device for collecting or measuring temperature information from the reactor, such as a thermometer, a temperature sensor or a thermal camera. co δ c \ ji cm o CO C \ l X cc CL 00 00 m δ CM 5 1. Förfarande för att utföra en reaction mellan en eller flera chemikalier och en processvätska, wilk förfarande innefattar steg, i wolf a. en Reactor anordnas som. en del av et flödesrör (12) som transporterar processvätskan, b. reactor tower förses med en inre yta, sluggish processvätskan flödar, 10 c. reactor reactor product electrochemical reactor reactor product reactor inre yta, d. the chemical process in the process reactor (30), e. the chemical process in the process, the chemical reactant in the antenna med in the chemical process, the image reaction. utfällningen av antingen chemicals / products eller reactionproducterna ytorna av reactor (10) eller anordningarna i samband därmed förebyggs, aftecknat av att h. utfällningen förebyggs genome att anordna et elvt reacting on 20 liten . 20. Reactor enligt face av föregäende patent krav 5-18, kännetecknad av att reactor (10) and försedd med en mätanordning som är en anordning för uppsamling eller mätning av thermurdata frän reactor, säsom en termometer, en tempurgivare eller en color camera. CO δ c \ j C \ J cp co C \ l X cc CL co co LO δ C \ J