JPS60501565A - Low concentration ozone bleaching reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Low concentration ozone bleaching reactor Background technology Technical field The present invention allows ozone to react with wood pulp at an extremely low concentration, and The present invention relates to a device for recycling liquid in a tank.

Conventional technology U.S. Pat. No. 4,216,054 to Bentbersin et al. discloses a process for treating wood pulp with ozone at less than %. 1982 1 U.S. Pat. No. 4,310.384 to Melchiis et al. Discloses a system for recycling water in degree ozonation treatment.

Old Shoe's U.S. Patent No. 3,966,542 claims that multiple shaft, thereby allowing material to be transported in multiple separate chambers. A processing system for mixing materials is disclosed.

U.S. Pat. No. 4,080,249 to Kemp et al. Discloses a system treated with ozone between % and %.

U.S. Patent No. 4,155.84'1 to Teyapuka et al. Disclosed.

U.S. Pat. No. 3,660,225 to Verrine et al. A white device is disclosed. U.S. Patent No. 3,941,650 to Nkinigu A screen cleaning means for a lulose digester is disclosed.

Carl Smith U.S. Patent No. 3.579.417 and Samuel Shin et al. No. 3,843,473 discloses an upstream cellulose digester. Ru.

U.S. Pat. No. 3,024,158 to Grangard et al. discloses a fire extinguisher with a side stream. It shows.

Summary of the invention Concentration is the concentration of oven-dried fibers in a mixture of fibers (filaments) and liquid. It's the amount. When processing pulp at low concentrations, the liquid usually cannot be reused. It is necessary to be able to do this. At 1% concentration, liquid is 99 times more dense than pulp. The weight will be . At 0.5%, the liquid weighs 199 times more than the pulp. other In this process, the pulp should have a high consistency. for example, It must be between 1.2 and 1.8% to form a good tont on a vacuum cleaner. Must be. To process low concentrations, a large filtrate pump with high power is required. and some modifications to the drop leg/tick-off equipment are required. Pal When transporting large amounts of water at low concentrations, the size of the pipeline may be prohibitive. In order to prevent this from occurring, the concentration is usually 2.5 to 4%.

In the present invention, water is reused at the treatment site, i.e. within the treatment system. Ru. The present invention combines a reactor in which ozone is mixed into pulp with a low concentration and a pulp separated from the reactor. The liquid is removed from the pulp before it enters the reactor, and this same liquid is added to the pulp when it enters the reactor. Provide a dehydration tank to which pulp is added.

The inner diameter of the return pipe is 17 to 45% of the inner diameter of the reactor. return passage Other shapes of can also be used. These have different cross sections and are placed in different positions Something will happen. In either case, the internal cross-sectional area is 7.5 mm of the internal diameter of the reactor. Equivalent to a circular cross section with an internal diameter of 7-45%.

Brief description of the drawing Figure 1 is a vertical view of the reactor to show the bottom dehydration chamber and outer return line. FIG.

Figures 2 to 5 are horizontal cross-sectional views of the reactor taken along the corresponding cross-sectional lines in Figure 1; It is.

Figure 6 shows the other parts of the reactor to show the top dehydration chamber seven outer return lines. FIG. 3 is a vertical cross-sectional view of the embodiment.

FIG. 7 is a vertical cross-sectional view of another embodiment of the dehydration chamber. This is the opposite of Figure 6. It is shown in the reactor or can also be used as a bottom dehydration chamber.

FIG. 8 is a horizontal cross-sectional view of the dehydration chamber taken along line 8-8 of FIG. .

9-10 are cross-sectional views of other embodiments of the dehydration chamber. those are the bottom Although shown as a top dehydration chamber, it can also be used as a top dehydration chamber. You can also do that.

Figure 11 shows another implementation of the dehydration chamber taken along line 1ll-11 in Figure 12. An example horizontal cross-sectional view.

FIG. 12 is a vertical cross-section of the dehydration chamber taken along line 12-12 of FIG. It is a diagram.

Figures 13 and 14 show the structure of the basket and screen shown in Figures 11 and 12. FIG. 13 is a perspective view for illustrating details of the The screen shown in Fig. 14 does not cover the screen.

15-16 show other embodiments of the dehydration chamber of FIGS. 11-13. Figure 15 is a partially sectional horizontal plan view; and FIG. 16 is a vertical cross-sectional view taken along line 16--16 of FIG.

Figure 17 is a reactor to illustrate the annular return line and bottom dehydration chamber. FIG.

18 is a horizontal cross-sectional view taken along line 18-18 of FIG. 17;

Figure 19 shows the reactor to show the annular return line and top dehydration chamber. FIG.

Figure 20 is a reactor to illustrate the central return line and top dehydration chamber. FIG. 21 along line 21-21 of FIG. FIG.

Description of the preferred embodiment The reactor has an outer shell 11, a cover 12 and a base 13. reaction The container is divided into a plurality of chambers 14a to 14g by separation plates 15cL to 15f. has been done. Each of the separation plates has a centrally located circular hole 16α to 16f. Ru. Each central circular hole has a diameter approximately one third of the diameter of the separator plate. The fluid is , passing from one chamber to the next through these circular holes.

A central shaft 17 extends through these circular holes. The shaft is a bearing rotate on top. The number of bearings is determined by the length of the shaft. Illustrated implementation In the example, there are three bearings: an upper bearing 18, a solid bearing 19, and a lower bearing 20. Illustrated. The central bearing 19 is a column extending between the outer shell and the bearing mounting. C is held in place by C. 21.

The shaft] 7 is rotated by a motor device 22. Chamber~14 Each of a to 14f is the inlet shaft attached to the shaft] 7-23G to 23 It has ff. The impeller can be of any suitable design. figure In the illustrated embodiment, four plate-shaped impellers are illustrated, but six plate-shaped impellers are shown. Impellers are also commonly used. The impeller is used in the pulp slurry inside the chamber. - and ozone. To prevent slurry from rotating in the chamber , a series of partition walls 24a-24f are positioned within each cell. Number and size of bulkheads The size is determined by the size of the reactor. Illustration 6 Machiomote Sho GO-50156 5(4) In the example given, four partition walls are illustrated within each cell.

The lower chamber of the reactor is a dehydration chamber. Pulp slurry is During its treatment in the reactor, the concentration ranges from 0.01% to about 0.07%. Ru. Liquid is removed from the pulp slurry before it leaves the reactor. , so the concentration of the slurry ranges from 0.5 to 4% when the pulp leaves the reactor. Be surrounded.

The dehydration chamber 14 (7) has a series of partition walls 25. The partition walls 25 5 is the same as the partition wall 24 of the other chambers except that it has a hole 26.

The holes 26 allow the filtrate to pass to the outer liquid part of the dehydration chamber.

The septum also serves as a support for the screen 27. screen 27 extends concentrically with the /gift 1f and the outer shell 11. screen 2 7 separates the dehydration chamber into an outer annular liquid chamber 28 and an inner slurry chamber. bar 29. The in-fourer 30 is attached to the shaft 17 . The outer edge of the impeller 30 has a metal foil 31. The metal foil 31 is a liquid can continue to pass through the screen at extremely high flow rates, and Screen to continue to prevent pulp buildup within the chamber. Remove the fiber cloak from the inner surface of the.

Screen 27 plays a different role than a normal pulp screen. normal pa Loop screens do not allow large clumps or bundled fibers on or on the screen. Enough passage of pulp fibers through the screen while retaining fiber bundles and fiber bundles. It has as many holes or slots as possible. In contrast, the present invention The purpose of the screen in the dehydration chamber is to allow water to pass through the screen. while allowing dehydration to retain all the fibers within the channel (- be. The preferred material for constructing the screen is stainless steel. . The holes should be treated so that pulp fibers cannot pass through the holes in the screen. The length of the pulp fibers should not be greater than the length of the pulp fibers. This is 0.8~2m m. The mensch size is usually 60.

Explain the operation. Pulp Slurry is the above Lupus Slurry RobiVive 32. Go through and enter chambers t4-a~14. /” and descends through this. In each of the layers 23a2 to 23f, the slurry is mixed with ozone by. Ozone is usually supplied through a pipe at the bottom of the reactor. 38 from the underside of the bottom impeller and rises through the chamber. Now, on the upper surface of the slurry in the chamber 14a! Lupus rally? leave.

The liquid in the lower Channojin - 14g! Slurry Chan for Malps Slurry It flows through the screen 27 while being accumulated in the bar 29. The slurry is The slurry exits through the exit pipe 34. Excess liquid is drained into the filtrate outlet 35. filtrate, is conveyed upwardly through the filtrate recirculation pipe 36 and into the reactor through the inlet 37. and reenters the chamber 14α. Pump 38 pumps liquid to chamber 14q. 14a. The operation illustrated in FIG. Because the slurry moves in the opposite direction to the ozone flow, it is called a reverse flow type. I can.

The filtrate recirculation pipe 26 has an inner diameter of 7.7-45% of the inner diameter of the reactor.

Usually the internal diameter of the recirculation pipe is 24% or less of the internal diameter of the reactor. Other recirculation passages Also can be used in place of this external pipe. These will be discussed later. . They have different cross sections and can be placed in different positions. Izu In both cases, the inner cross-sectional area is a circle with an inner diameter of 7.7 to 45% of the inner diameter of the reactor. It will be equivalent to the shape cross section. The preferred size would be the same.

FIG. 6 illustrates another embodiment in which the slurry and ozone flow in one direction. pa Lupus slurry and A-sin both move upward in the same direction. Figure 6 The difference between the reactor illustrated in Figure 1 and the reactor illustrated in Figure 1 is that the pulp slurry The only difference is that the positions of the inlet and dehydration chamber are reversed. pulp slurry The inlet is located at the bottom of the reactor, and the dehydration chamber is located at the top of the reactor. It is location. This indicates the preferred location of the inlet and dehydration chamber.

The same reference numbers are used in FIGS. 1 and 6.

In FIG. 6, both the valve slurry and ozone enter from the bottom of the reactor; Move upward through the reactor. and they are odor-filled within each chamber. and mixed. In the upper chamber, the slurry is dehydrated in the same manner as in Figure 1. and excess liquid is forced downward to return to the bottom chamber. Ru. The relationship of the internal diameter of the recirculation line to the reactor is shown in the system of Figures 1 to 5. It is similar to

The advantage of having the dehydration chamber located at the top is that the liquid is transferred to the outside of the filtrate through the circulation pipe 36. ', no pump 38 is required to flow through the '. pressure head reactor between the ozone-exposed contents of and the gas-free filtrate in the recirculation pipe. This occurs due to the difference in the density of

When the flow is from the upper dewatering chamber to the lower side, the recirculation pipe The preferred internal diameter is 20-30% of the internal diameter of the reactor.

Figures 7 and 8 illustrate other embodiments of the dehydration chamber. This example , the outer annular chamber 39 is a slurry chamber and the inner annular chamber 39 is a slurry chamber. The annular chamber 40 is the filtrate chamber C. The filtrate enters the outer annular chamber 39 to the inner annular chamber 40 , the metal foil 41 passes through the screen 27 “located on the outside of the screen. Therefore, the screen will be damaged by the impeller less likely. Metal foil 41 removes pulp mat from screen 27″ do. The metal foil 41 is attached to the impeller arm 4 of the dehydration chamber impeller device 43. It consists of two inner edges. The impeller arm 42 is connected to the impeller element 4 4 to the central shaft 17.

An inner annular filtrate chamber 40 extends upwardly from the dividing plate 15a,''.

The annular structure has an inner cylindrical wall 45, an upper wall 46 and an inner wall 4. 5 and a concentric outer cylindrical screen 27''. The annular sheath formed by is connected to the filtrate outlet 36'' by a pipe 47. tied together.

Some gas will tend to collect in the annular gas and therefore this A suction device 48 is provided in the annular space and opens at the upper end thereof. It is. Gas is thereby sucked out from within the space. Remaining reference numbers are the same.

This dehydration chamber operation allows excess fluid to flow outward through the screen. except that it is sucked inward through the screen rather than being forced through the screen. It is the same as other dehydration chambers. The impeller is also screened in this case. Clean fibers, or fibres, from the yarn.

Figures 9 and 10 show other implementations of the screen and impeller in the dehydration chamber. An example is illustrated. Figure 9 1 The screen 271h has a convex shape toward the center.

The screen 27 in FIG. 10 is designed to provide a larger surface area. It is shaped like an accordion.

Figures 11-15 illustrate geometries for two dehydration chambers. child These structures maintain the shape of the screen and keep the screen clean. Leave it as is. Screen 277/7// is retained within basket 50 . The basket 50 has upper and lower rings 51 and 52 and is fixed. An outer bar 53 extends between these rings. Screen 277/// / is positioned inside these rods and is provided by an inner rod 54 which is removable. The outer rod 53 is then secured by screws, bolts and other fastening devices 55.

A perforated backing plate can be used to protect the screen. drawing The pressure applied to the screen depends on whether you use it or not. determined depending on.

In the drawings, a backing plate with holes in place is shown.

They are positioned on the liquid chamber side of the screen. Figure 11~ In Figure 15, a perforated backing plate 56 extends between the outer a53. other In embodiments, the backing plate can be omitted.

Such a structure is illustrated in FIGS. 12-14. Upper ring 51 has an inner horizontal annular plate 57 and a flange 58 extending downward. Ru.

2 Flange 58 and plate 57 form an inner shoulder 59 and an outer shoulder 60. lower phosphorus The ring consists of a horizontal annular plate 61 and a flange 62 extending upward. structure, which form inner and outer shoulders 63,64.

The outer rod 53 fits within the outer shoulder 60.64 and is attached to the ring 51.52. Fixed. The inner rod 54 fits within the inner shoulder 59.63 and is tightened. It is fixed to the ring 51,52 and to the outer rod 53 by means of a fastening device 55. Ne is illustrated. Screen 27 //Ill is the inner rod 51 and the outer rod 52.

Due to the pressure of the fibers and slurry against the screen 27 Z/7//, the screen The ring may be torn along the outer ridge 53. To prevent this, some people The law is being followed. For example, on the outer wall adjacent to screen 277//// Cut the cutter part at an angle to avoid forming any cutting edges. can be removed. A perforated backing plate 56 may also be provided. child These boards are installed on the Hirohara side of the screen 27 Stretch out and support the screen. These plates form the outer shoulder 6 of the ring 51,52. 0.64 and fastened.

Each of the backing plates 56 has holes 65' through which fluid passes! i='lj. hole size The size and number are slugs relative to the screen. on a plane that matches the contours of the ring and screen, determined by the pressure of the The plate supports the screen and prevents it from tearing. The pressure is too big If necessary, the backing plate can be omitted.

The slurry in the cylinder formed by the screen 2777// is covered with metal foil. 66 to maintain a turbulent flow at a position adjacent to the screen. It will be done. The metal foil 66 has a cylindrical shape formed by the inner surface of the inner rod 54. Rotate the inner peripheral part of. The turbulence of the slurry formed by the metal foil is , that is, so that the fibers do not block the screen 27/77'/. is maintained. The metal foil 66 is attached to the center by upper and lower arms 67.68. It is attached to the shaft 17"'. The number of metal foils depends on the size of the basket. and slurry format vs. concentration. Four metal foils are shown .

The speed of these metal foils is determined by the speed of the screen at the position where the screen is operated. can be determined to maximize the pressure drop across the tube. fast speed The greater the pressure loss, the greater the pressure loss. However, the speed of the motor The larger the screen, the more likely it is that the screen will tear. the screen is torn Another way to prevent this is to slow down the speed of the rotating body.

According to one experiment, a screen with an exposed area of 17 square feet (0,158 m2) The lean and backing plates allow the stock to be made sufficiently thick, and [To ensure that it does not break even when the speed of 1-ter is set to 6.4 m 1 second. was completed. This unit produces 770 gallons/minute (2914 gallons/minute) of 0.3% concentration valves. , 51/min).

Figures 15 and 16 show that the slurry flow is on the inside rather than on the outside. 3 illustrates a preferred basket screen housing in such an embodiment;

The difference between this structure and the structure illustrated in FIGS. 11-14 is that the outer rod 53' movable, the inner bar 54' is identified, and the fastening device 55' moves the outer bar inwards. Attach it to the rod of the and a metal foil 66' is positioned on the outside of the screen. and is held only by the upper arm 68'. other references The numbers, structure and operation are the same as in FIG.

The recirculation line can have a cross section other than circular. For example, The squares can be square or hexagonal. The filtrate external circulation line It forms an annular body around the loop 11. This latter structure is shown in Figs. Illustrated in FIG. The return line consists of an annular band 69. ringed rita With the exception of the green line, this reactor is similar to the reactor illustrated in FIG. Yui One difference is that the filtrate enters the annular passage 69 from the return line 70; Up 5 through the road It is forced to flow toward the upper chamber 14a'' through the hole 71. This is the point where it falls within ``''''. Other reference numbers are the same as in FIG.

Figure 19 shows the annular return line used in models where fluid flows in the same direction. Illustrated. Reactor 107/77/7// is the reactor 10 illustrated in FIG. ’ has the same flow pattern. In reactor IQ /7//If/7 (C) The filtrate passes through the hole 71' and enters the annular passage 69'. move downward and pass through the hole 72 into the lower chamber t, 4 f L//rL JL/Go inside. The rest of the device, reference numbers and operation are similar to those in Figure 6. be.

The filtrate extracirculation line is located inside the reactor rather than outside. this Examples are illustrated in FIGS. 20-21. This 1. In the figure, the recirculating line The engine consists of a central shaft 73. The upper chamber j4″″″″′ is , is a dehydration chamber, and the flow of slurry and filtrate is similar to that shown in Figure 7. Ru. The slurry is located outside the dewatering device 74. The filtrate is sent to the dehydrator 74. through the screen 75, the hole 76 in the shaft 73, the shaft 73 on the underside, and Pass through hole 77 to the outside and lower chamber 14 f7J/J7/// / Go inside.

The dewatering device 74 is attached to the shaft 73 by upper and lower plates 78,79. It rotates together with the shaft. The screen 75 can be any suitable screen. According to the law, you can visit board 78 and 79. This sixth Structures similar to those illustrated in FIGS. 15 and 16 are preferred. child In this structure, the upper wall 46' is equivalent to the upper plate 78 and has an inner surface. The wall 45' is equivalent to the shaft 73, and the separating plate 15a////// is It is equivalent to the lower plate 79.

The metal foil 80 is located at the end of the regulator partition 24 aHIIIH/.

Circular plate located above hole 77 in chamber l4 f/J///l//L 81 is a small area of circulation of liquid as it moves upward through the reactor. Prevent rings. The hole 77 is located between the plate 81 and the impeller 23f""""'. Ru. The remaining parts of the apparatus, reference numbers and operation are similar to those in FIG. 19.

In all these structures, the cross-sectional dimensions of the return line are It is equivalent to a circular cross section with an inner diameter of 7.7% to 45% of the inner diameter. This dimension is “Equivalent diameter” for all types and cross sections of turnlines or pipes. You can call. A typical equivalent internal diameter is 77-24% of the reactor internal diameter.

The equivalent inner diameter of the downward flow is then 20-30% of the inner diameter of the reactor.

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Claims (1)

[Claims] 1. Mix wood pulp slurry and liquid to produce low concentration wood pulp slurry. mix the slurry with a drug, and then remove the liquid from the slurry. equipment to recycle and add the liquid to a new additional slurry. At the location, a plurality of chambers, the chambers including two end chambers; One end chamber consists of a dehydration chamber and the remaining chambers contain a mixing chamber. chambers; each pair of adjacent chambers; A passageway between In order to mix the slurry, an oven t7. z device ; The above chamber is divided into a pulp slurry chamber part and a liquid chamber. A screen installed in the dehydration chamber, which allows the valve fibers or the above-mentioned pulps to a screen to prevent passage of liquid from the rally chamber into the liquid chamber; An inlet passage provided at the other end of the above-mentioned end nayanhar; the above-mentioned pulp slurry char; provided in the dehydration chamber connecting the chamber and the outlet of the dehydration chamber. an exit passageway; and A liquid recycle passageway between said liquid chamber and said other end chamber. So, the equivalent day in the above chamber Liquid recycling made to have an equivalent internal diameter ranging from 7.7 to 45% of the internal diameter aisle; It consists of: The passageway between the dehydration chamber and the adjacent mixing chamber is be located between the mixing chamber and the pulp slurry chamber. A device consisting of a passageway. 2. In the device according to claim 1, the liquid recycling passage is A device consisting of a single pipe located outside the chamber. a. The device according to claim 1, further comprising a central shaft. and the mixing means and the screen cleaning means are attached to the central shaft. A device that can be used. 4. The device according to claim 3, wherein the fluid recycling passage is A device installed within a central shaft. 5. The device according to claim 3, wherein the screen is connected to the chamber. the device comprises a cylinder having an axis aligned with the axis of the cylinder; A basket that holds the clean in place, parallel to the screen above. having two aligned cooperating inner and outer rods; The rods define the cylinder, and a passage is provided between a pair of adjacent rods. There is one screen above. and the inner and outer rods are held between said pairs of inner and outer rods. eL The device according to claim 5, further comprising: the screen adjacent to the rod; A device comprising a perforated backing plate in the liquid chamber between the lean and the liquid chamber. Place. 7. The device according to claim 1, wherein the screen is connected to the chamber. a cylinder having an axis aligned with the axis of the cylinder; A basket that holds the clean in place, parallel to the screen above. It has two matching cooperating inner and outer sides, The rods define the cylinder and a passage is provided between a pair of adjacent rods. The screen is separated by the paired inner and outer bars. A device that is held in & The device according to claim 7, further comprising the screen adjacent to the rod. A device comprising a backing plate with holes in the liquid chamber (C) between the lean and the liquid chamber. 9. The device according to claim 1, wherein the dehydration chamber is A device consisting of an upper chamber. 10. In the apparatus according to claim 9, the equivalent inner diameter of the recycling passage is 20 to 30% of the equivalent inner diameter of the chatter bar. 1], the apparatus according to claim 9, wherein the liquid recycling passage is A device consisting of a single pipe installed outside the chamber. 12. The device according to claim 9, further comprising a central shaft. and the mixing means and the screen cleaning means are located in the central part. A device that can be installed and removed. 1a. The apparatus according to claim 12, wherein the liquid fluid recycling channel is The path is in the center shaft above. A device that is equipped with a 14. The device according to claim 12, wherein the screen is connected to the chamber. The device consists of a cylinder with an axis aligned with the axis of the bar; a basket for holding the screen in place; having cooperating inner and outer bars that align and align; The two rods define the cylinder, and there is a passageway between each pair of adjacent rods. It is provided that the screen is supported by the paired inner and outer bars. A device held between 15. The device according to claim 14, further comprising an upper d adjacent to the rod. It includes a liner with perforated holes provided in the liquid chamber between the self-screen and the liquid chamber. A device made of IG. The apparatus according to claim 9, wherein the screen is connected to the chamber. The device consists of a zolinbe containing @ aligned with the axis of the Scree-1 a basket that holds the screen in place parallel and aligned with the screen; has cooperating inner and outer rods that The rods define the cylinder (C) and there is a passage between a pair of adjacent rods. The screen is defined by the pair of inner and outer bars. A device held in between. 17. The device according to claim 16, further comprising: A device comprising a perforated temporary lining in said liquid chamber between said screen and said liquid chamber. . 1 & Claims 1. The device according to claim 1, wherein the dehydration chamber is A device consisting of a lower chamber. 19 The device according to claim 18 (where τ is the equivalent inner diameter of the recycling passage) or an apparatus having an equivalent inner diameter of 7.7 to 24'Po. 2. The device according to claim 18, wherein the liquid recycling passage is A device consisting of a single pipe installed outside the chamber. 21. In the device according to claim 18, the central shaft is further provided with a , and the mixing means and the screen cleaning means are attached to the seventh shaft in the center of the upper part. A device that is attached to a 2. The device according to claim 18 (in an IC, the screen or the It consists of a cylinder with an axis aligned with the axis of the chamber, and is further equipped with the above-mentioned equipment. The location is the above screen 2 a basket for holding one screen in place parallel and aligned with said screen; Inner 14I] and Outer 1! 'lll rod, When the rods define the cylinder, a passage is provided between a pair of adjacent rods. - said screen is defined by said paired inner and outer frames; A device that is held in between. 2a The device according to claim 22 (and further adjacent to the rod) A hole with a hole is provided in the liquid chamber between the screen and the screen. Device. l