CN220520963U - System for washing, selecting and bleaching chemical pulp - Google Patents
System for washing, selecting and bleaching chemical pulp Download PDFInfo
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- CN220520963U CN220520963U CN202321708682.2U CN202321708682U CN220520963U CN 220520963 U CN220520963 U CN 220520963U CN 202321708682 U CN202321708682 U CN 202321708682U CN 220520963 U CN220520963 U CN 220520963U
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- 238000004061 bleaching Methods 0.000 title claims abstract description 101
- 238000005406 washing Methods 0.000 title claims abstract description 51
- 229920001131 Pulp (paper) Polymers 0.000 title claims abstract description 14
- 238000012216 screening Methods 0.000 claims abstract description 205
- 239000000706 filtrate Substances 0.000 claims abstract description 35
- 238000000034 method Methods 0.000 claims abstract description 13
- 238000010411 cooking Methods 0.000 claims abstract description 5
- 239000002002 slurry Substances 0.000 claims description 66
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 39
- 239000001301 oxygen Substances 0.000 claims description 39
- 229910052760 oxygen Inorganic materials 0.000 claims description 39
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 30
- 239000004576 sand Substances 0.000 claims description 28
- 238000006243 chemical reaction Methods 0.000 claims description 26
- 238000010790 dilution Methods 0.000 claims description 25
- 239000012895 dilution Substances 0.000 claims description 25
- 239000002893 slag Substances 0.000 claims description 20
- JTJMJGYZQZDUJJ-UHFFFAOYSA-N phencyclidine Chemical class C1CCCCN1C1(C=2C=CC=CC=2)CCCCC1 JTJMJGYZQZDUJJ-UHFFFAOYSA-N 0.000 claims description 15
- 238000002156 mixing Methods 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 3
- 235000017166 Bambusa arundinacea Nutrition 0.000 abstract description 19
- 235000017491 Bambusa tulda Nutrition 0.000 abstract description 19
- 241001330002 Bambuseae Species 0.000 abstract description 19
- 235000015334 Phyllostachys viridis Nutrition 0.000 abstract description 19
- 239000011425 bamboo Substances 0.000 abstract description 19
- 238000004537 pulping Methods 0.000 abstract description 6
- 239000012535 impurity Substances 0.000 description 24
- 239000000835 fiber Substances 0.000 description 18
- 239000007788 liquid Substances 0.000 description 13
- 230000000694 effects Effects 0.000 description 9
- 238000010025 steaming Methods 0.000 description 7
- 238000004140 cleaning Methods 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000003513 alkali Substances 0.000 description 4
- 239000012141 concentrate Substances 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- 230000002378 acidificating effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000007844 bleaching agent Substances 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 229920005610 lignin Polymers 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003139 buffering effect Effects 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 210000002421 cell wall Anatomy 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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Abstract
The utility model relates to the pulping field, and discloses a chemical pulp washing, selecting and bleaching system which comprises a screening system, a bleaching system and a pulp washing system, wherein the screening system comprises a section removing machine and a multi-section fine screening system, the pulp washing system comprises a coarse screen section pulp washing machine and a fine screen section pulp washing machine, the section removing machine, the coarse screen section pulp washing machine, the multi-section fine screening system, the fine screen section pulp washing machine and the bleaching system are sequentially connected with a filtrate outlet of the coarse screen section pulp washing machine and a cooking system in the previous working procedure, and a filtrate outlet of the fine screen section pulp washing machine is connected with the multi-section fine screening system. So as to improve the screening and bleaching efficiency of the bamboo pulp.
Description
Technical Field
The utility model relates to the field of pulping, in particular to a chemical pulp washing and bleaching system.
Background
The preparation process of the bamboo pulp mainly comprises the procedures of cooking, screening, pulp washing, bleaching, papermaking and the like. After the bamboo chips are steamed by the steaming system, impurities in the slurry are removed by the screening system, so that the quality of the slurry can be improved, and the influence of the impurities on chemical reaction in a bleaching process can be prevented, thereby improving the bleaching efficiency.
Compared with wood pulp, the bamboo joints and other hard impurities in the bamboo pulp are more, if the concentration of the bamboo pulp is reduced, the screening efficiency is low, if the concentration of the bamboo pulp is increased, the fibers in the tail pulp are more, the fiber loss is large, and how to ensure the efficiency and reduce the fiber loss, so that the screening and bleaching efficiency of the bamboo pulp is improved, and the method is urgent.
Disclosure of Invention
The utility model aims to provide a chemical pulp washing and bleaching system which improves the screening and bleaching efficiency of bamboo pulp.
In order to achieve the above purpose, the utility model adopts the following technical scheme: the screening system comprises a section removing machine and a multi-section fine screening system, wherein the pulp washing system comprises a coarse screening section pulp washing machine and a fine screening section pulp washing machine, the section removing machine, the coarse screening section pulp washing machine, the multi-section fine screening system, the fine screening section pulp washing machine and the bleaching system are sequentially connected, a filtrate outlet of the coarse screening section pulp washing machine is connected with a cooking system in the previous working procedure, and a filtrate outlet of the fine screening section pulp washing machine is connected with the multi-section fine screening system.
The beneficial effect of this scheme is:
1. and (3) a section removing stage: the bamboo chips are steamed at high temperature to become slurry, the knot remover removes large bamboo joints in the slurry, then the slurry is cleaned by the coarse screen section pulp washer, at the moment, the temperature of filtrate produced by the coarse screen section pulp washer is higher and residual alkali is more because the slurry just comes out of the steaming pot, and at the moment, the filtrate of the coarse screen section pulp washer is recovered and used in a steaming system of the previous working procedure, so that heat energy and residual alkali in the filtrate can be recycled.
2. Fine screening: the impurities in the slurry are screened out through the multi-section fine screening system, the slurry screened by the multi-section fine screening system enters the fine screening section pulp washer, and the concentration of the slurry is adjusted by the fine screening section pulp washer so as to meet the concentration requirement of the bleaching system. Through the screening of multistage fine screening system, the temperature drops after thick liquid and a plurality of screening equipment contact, and at this moment, fine screening section pulp washer produces the filtrate temperature lower, uses the filtrate of fine screening section pulp washer in multistage fine screening system, recycle fine screening section pulp washer's filtrate to water economy resource, environmental protection, reduction emission.
The filtrate of the fine screening section pulp washer is used in a multi-section fine screening system, so that the temperature of slurry in the multi-section fine screening system is further reduced, and the screening and bleaching efficiency is further improved. Specifically, after the slurry is steamed, the temperature is higher, the materials of the medium and small impurities are softer, and the impurities are easy to crush due to collision and pass through screening when sieving; and after the temperature is reduced, the impurity becomes compact, the hardness degree rises, the impurity is not easy to break, and the impurity is more easily screened out, so that the effect of bleaching is prevented from being influenced by the impurity, and the screening and bleaching efficiency is improved.
3. Bleaching: the slurry enters a bleaching system, the bleaching system is heated according to the temperature required by bleaching at different stages, and different bleaching agents are added for bleaching.
Preferably, as an improvement, the multistage fine screening system comprises a first stage fine screening device, a sand remover, a second stage fine screening device, a third stage fine screening device, a slag washer and a dilution vertical pipe, wherein a screening outlet of the first stage fine screening device is connected with the pulp washer, a screening outlet of the first stage fine screening device is connected with the sand remover, a screening outlet of the sand remover is connected with the second stage fine screening device, a screening outlet of the second stage fine screening device is connected with the first stage fine screening device, a screening outlet of the second stage fine screening device is connected with the third stage fine screening device, a screening outlet of the third stage fine screening device is connected with the slag washer, a screening outlet of the slag washer is connected with the third stage fine screening device, a filtrate outlet of the fine screening section pulp washer is connected with the dilution vertical pipe, and the dilution vertical pipe is simultaneously connected with the first stage fine screening device, the sand remover, the second stage fine screening device and the third stage fine screening device. So set up, there is the following effect:
1. the primary pulp screened by the primary fine screening equipment enters the next procedure, the primary tail pulp screened by the primary fine screening equipment enters the sand remover, the primary pulp screened by the sand remover enters the secondary fine screening equipment, the secondary fine pulp screened by the secondary fine screening equipment enters the primary fine screening equipment, the secondary tail pulp screened by the secondary fine screening equipment enters the tertiary fine screening equipment, the fine pulp screened by the tertiary fine screening equipment enters the secondary fine screening equipment, the tail pulp screened by the tertiary fine screening equipment enters the slag washer, the fine pulp screened by the slag washer enters the tertiary fine screening equipment, and the filtrate of the fine screening section pulp washer can enter the dilution riser.
2. After the slurry enters the first-stage fine screening equipment, as part of the fibers are adhered to the impurities to form blocks, the fibers cannot pass through the screen plate and can only enter the sand remover along with the first-stage tail slurry, at the moment, the liquid in the dilution vertical pipe dilutes the first-stage tail slurry and then enters the sand remover, the first-stage tail slurry rotates at a high speed in the sand remover, the heavier impurities and the fibers are separated under the action of centrifugal force, the heavier impurities are discharged downwards, and the lighter fibers are discharged upwards and enter the second-stage fine screening equipment. If the slurry enters the sand remover first and then enters a section of fine screening equipment, more fibers in the slurry are difficult to scatter, and most of the fibers are discharged downwards along with the impurities after entering the sand remover, so that the fiber loss is large and the slurry yield is low; in this scheme, through one section fine screening equipment screening, most fibre has been selected out and get into fine screening section pulp washer, and remaining fibre is through the liquid dilution, and the combination of fibre and impurity is no longer inseparable, and the desander can be with impurity and fibre separation more easily, and then has reduced the fibre loss, has improved the yield.
3. And enabling the second-section fine screening equipment to screen the second-section fine pulp again to form a first screening cycle, and enabling the third-section fine screening equipment to screen the fine pulp to enter the second-section fine screening equipment to form a second screening cycle. For some workshops with limited places, the primary fine screening equipment, the sand remover, the secondary fine screening equipment and the tertiary fine screening equipment are connected in sequence, the primary fine screening equipment and the tertiary fine screening equipment are furthest apart, and compared with the condition that the good pulp screened by the tertiary fine screening equipment directly enters the primary fine screening equipment to form a large screening cycle, the length of each screening cycle in the scheme is shorter, the length of a used total pipeline is shorter, the flow is shorter, the circulation time is shorter, and the screening efficiency is higher.
4. And finally, cleaning the tail pulp screened out by the three-section fine screening equipment, washing out residual fibers in the tail pulp, avoiding wasting the fibers, enabling the good pulp washed out by the slag washing machine to enter the three-section fine screening equipment to form a third screening cycle, and making up the problem of low screening efficiency of the low-concentration tail pulp by quick circulation, wherein the cycle length is short.
5. In the subsequent process of the multi-section fine screen system, the fine screen section pulp washer is farther away from the cooking process, so that the temperature of filtrate produced by the fine screen section pulp washer is lower, and the temperature of the system can be effectively reduced by using the filtrate in the multi-section fine screen system, thereby improving the screening efficiency.
The filtrate of the fine screen section pulp washer can enter a dilution vertical pipe for storage, and the slurry in each stage is diluted in three fine screen devices respectively, so that the concentration of the slurry is controlled to achieve the optimal screening efficiency; meanwhile, as the three fine screening devices all use the liquid in the dilution vertical pipe for dilution, the temperature difference is small, so that the concentration can be adjusted at any time according to the properties of the slurry.
6. The node removing stage has higher temperature due to the fact that the node removing stage just passes through the steaming and boiling; the bleaching stage is to ensure the reaction efficiency of the bleaching agent and has a certain temperature; in the fine screening stage, the temperature reduction can improve the screening efficiency, so that heating is not needed, a set of independent liquid circulation system is needed, the normal temperature is kept, and the filtrate of the fine screening section pulp washer flows back into the dilution vertical pipe, so that the liquid circulation system can be formed.
Preferably, as an improvement, the sand remover comprises a pulp inlet pipe, a pulp outlet pipe and a plurality of conical cyclones, wherein the pulp inlet pipe is arranged right below the pulp outlet pipe in parallel, the conical cyclones are evenly distributed on two sides of the pulp inlet pipe and the pulp outlet pipe in a quincuncial shape, the lower ends of the conical cyclones are connected with the side surfaces of the pulp inlet pipe, and the upper ends of the conical cyclones are connected with the side surfaces of the pulp outlet pipe. So set up, there is the following effect:
1. for guaranteeing screening efficiency, need guarantee the flow in the desander, if use a large-scale degritting unit, then the energy consumption is big, take up an area of big, degritting speed is slow, impurity has destroyed fibrous structure in degritting unit internal collision, and this scheme uses a plurality of toper degritting units cooperation to use, make full use of advances the space of thick liquid pipe and play thick liquid pipe both sides, the energy consumption is little, take up an area of for a short time, because every toper degritting unit is less relatively, the rock amplitude of thick liquid is little, the collision between the impurity is less, be difficult for destroying fibrous structure, also can not produce less impurity because of the collision between the impurity, and then lead to less impurity to be in the same place with thick liquid mixture and be difficult for being screened out.
2. The slurry is divided into a plurality of strands and passes through the conical sand removal unit, so that the heat dissipation area of the slurry is increased, and the subsequent screening efficiency is prevented from being reduced due to the temperature rise.
Preferably, as an improvement, the pulp washing system further comprises a screening pulp washer, an oxygen-stripping section pulp washer, a D0 section pulp washer, an EOP section pulp washer, a D1 section pulp washer and a return pipe, wherein filtrate of the screening pulp washer can enter the dilution riser through the return pipe; the bleaching system comprises an oxygen-removing bleaching device, a D0 section bleaching device, an EOP section bleaching device and a D1 bleaching device, and the screening pulp washer, the oxygen-removing bleaching device, the oxygen-removing section pulp washer, the D0 section bleaching device, the D0 section pulp washer, the EOP section bleaching device, the EOP section pulp washer, the D1 bleaching device and the D1 section pulp washer are sequentially connected. So set up, there is the following effect:
1. after the oxygen-removing stage is finished, the slurry is cleaned by an oxygen-removing stage pulp washer, and the removed lignin is cleaned away, so that the lignin is prevented from influencing the reduction reaction of the D0 stage, the reaction of the D0 stage is enabled to be more sufficient and rapid, and the bleaching efficiency is further improved.
After the D0 stage is finished, the slurry is washed by a D0 pulp washer, acidic substances generated in the D0 stage are washed away, so that the acidic substances react with alkaline substances in the EOP stage, the bleaching effect of the oxidation reaction in the D1 stage is further enhanced, and the bleaching efficiency is further improved.
And 3, after the D1 stage is finished, cleaning the slurry by a D1 stage pulp washer, washing off residual alkaline substances in the D1 stage, and then storing the slurry, thereby improving the bleaching efficiency.
4. The slurry concentration is controlled to a higher concentration by the washer to ensure the reaction rate.
Preferably, as an improvement, the oxygen-removing bleaching device comprises an oxygen-removing middle-concentration vertical pipe, a first oxygen mixer, an oxygen pre-reaction pipe, an oxygen-removing steam injector, a second oxygen mixer and an oxygen reaction tower which are connected in sequence, wherein a NaOH feeding port and a Mg (OH) 2 feeding port are arranged in the oxygen-removing middle-concentration vertical pipe, and the first oxygen mixer and the second oxygen mixer can respectively feed O 2 And mixing the slurry. So set up, there is the following effect:
1. NaOH and Mg (OH) 2 are introduced into the oxygen stripping and concentrating vertical pipe, so that the slurry maintains alkaline environment required by oxidation, wherein the Mg (OH) 2 is used as a masking agent to mask metal ions such as Ca and the like to interfere subsequent oxidation reaction, and further the bleaching effect is improved.
2. Because the cell walls of the bamboo fibers are basically free of tattoos and fineCell wall thickness, small cell cavity, O 2 Is difficult to permeate into bamboo pulp, in the scheme, a first oxygen mixer makes the pulp and O 2 Fully mixing, and making the slurry enter an oxygen pre-reaction tube and O 2 The pre-reaction is carried out, then steam is sprayed by the oxygen steam removal sprayer to reach the designed temperature, compared with direct steam spraying, a great amount of steam resources are saved, partial bamboo pulp is oxidized first, and the follow-up steam is easier to enter the bamboo pulp.
3. After passing through the fine screening system and the fine screening section pulp washer, oxygen (O) is added into the first oxygen mixer 2 ) The oxygen in the slurry is heated and expanded through the oxygen steam removal ejector, the larger the front-rear temperature difference is, the more the oxygen is in the space of expanding in the slurry, and at the moment, the oxygen can be more easily mixed with the slurry by adding the oxygen through the second oxygen mixer.
Preferably, as an improvement, the oxygen-stripping-stage pulp washer comprises a first oxygen-stripping-stage pulp washer and a second oxygen-stripping-stage pulp washer, and the second oxygen-stripping-stage pulp washer is provided with a steam inlet. So set up, wash the cooling to thick liquid with the first oxygen of normal atmospheric temperature and take off section pulp washer earlier, then the second oxygen that the steam heated takes off section pulp washer washs thick liquid, improves cleaning performance through cold and hot alternation, and then washs the residual oxide.
Preferably, as an improvement, the D0 section bleaching device comprises a D0 medium-concentration vertical pipe, a D0 steam ejector, a D0 mixer and a D0 reaction tower which are connected in sequence, wherein the D0 medium-concentration vertical pipe is provided with H 2 SO 4 The D0 mixer is provided with a ClO 2 A feed inlet; the EOP section bleaching device comprises an EOP middle-concentration vertical pipe, an EOP mixer and an EOP reaction tower which are sequentially connected, wherein the EOP middle-concentration vertical pipe is provided with a steam inlet, a NaOH feeding port and H 2 O charging port 2 The EOP mixer can mix O 2 Mixing with the slurry; the D1 bleaching device comprises a D1 medium-concentration vertical pipe, a D1 mixer and a D1 reaction tower which are sequentially connected, wherein the D1 medium-concentration vertical pipe is provided with a NaOH feeding port, and the D1 mixer is provided with ClO 2 And a charging port. So arranged, in section D0, by H 2 SO 4 Allowing the slurry to reach a designed pH by ClO 2 Reducing the slurry to further achieve the purpose of bleaching; in EOP segment, through H 2 O 2 And O 2 Bleaching by intensified alkali extraction; in the D1 stage, clO is used again after alkali extraction 2 Oxidation reaction is carried out, and the bleaching effect of the slurry is improved through multiple bleaching.
Preferably, as a modification, the D1 section pulp washer is provided with Na 2 S 2 O 3 And a charging port. So arranged, through Na 2 S 2 O 3 And residual chlorine which is not reacted in the slurry is neutralized, so that pollution emission is reduced.
Drawings
FIG. 1 is a general schematic of an embodiment;
FIG. 2 is a schematic diagram of an embodiment multi-stage fine screening system;
FIG. 3 is a schematic diagram of an oxygen-decarbonizing bleaching apparatus of an embodiment;
FIG. 4 is a schematic diagram of a D0 stage bleaching apparatus of an embodiment;
FIG. 5 is a schematic diagram of an EOP stage bleaching apparatus according to an embodiment;
FIG. 6 is a schematic diagram of a D1 stage bleaching apparatus of an embodiment;
fig. 7 is a front view of the sand remover of embodiment 2;
fig. 8 is a top view of the sand remover of embodiment 2.
Detailed Description
The following is a further detailed description of the embodiments:
reference numerals in the drawings of the specification include: coarse screen washer 111, fine screen washer 112, first oxygen-stripping section washer 121, second oxygen-stripping section washer 122, D0 section washer 130, EOP section washer 140, D1 section washer 150, return line 160, oxygen-stripping bleaching apparatus 210, oxygen-stripping medium concentration riser 211, oxygen-stripping medium concentration pump 212, first oxygen mixer 213, oxygen pre-reaction tube 214, oxygen-stripping steam ejector 215, second oxygen mixer 216, oxygen reaction tower 217, oxygen-stripping feed pump 218, pre-bleaching riser 221, pre-bleaching feed trough 222, pre-bleaching feed pump 223, pre-bleaching feed pump 224, D0 section bleaching apparatus 230, D0 medium concentration riser 231, D0 medium concentration pump 232, D0 steam ejector 233, D0 mixer 234 the D0 reaction tower 235, D0 feed pump 236, EOP stage bleaching unit 240, EOP middle concentrate standpipe 241, EOP middle concentrate pump 242, EOP mixer 243, EOP reaction tower 244, EOP feed pump 245, D1 stage bleaching unit 250, D1 middle concentrate standpipe 251, D1 middle concentrate pump 252, D1 mixer 253, D1 reaction tower 254, pulping tower 260, section remover 300, filtrate tank 400, multi-stage fine screening system 500, buffer standpipe 510, primary fine screening apparatus 520, sand remover 530, pulp inlet pipe 531, pulp outlet pipe 532, conical cyclone 533, connecting branch 534, frame 535, slag discharge tank 536, secondary fine screening apparatus 540, tertiary fine screening apparatus 550, slag washer 560, dilution standpipe 570.
Example 1
Example 1 substantially as shown in fig. 1 to 6, example 1 includes a screening system, a bleaching system and a pulp washing system, wherein the pulp washing system includes a coarse screen pulp washer 111, a fine screen pulp washer 112 and a return pipe 160, the screening system includes a joint remover 300, a joint washer, a filtrate tank 400 and a multi-stage fine screen system 500, as shown in fig. 1, bamboo chips steamed by the previous steaming process are sprayed into pulp by a spray pot under high pressure, and then enter the joint remover 300, the joint remover 300 is FCJ-4, bamboo joints and hard lumps of the non-formed pulp in the pulp are removed by the joint remover 300, the pulp obtained at this time is coarse pulp, the joint remover 300, the coarse pulp washer 111 and the multi-stage fine screen system 500 are sequentially connected, the coarse pulp enters the coarse screen washer 111 for cleaning, and the coarse pulp cleaned by the coarse screen washer 111 enters the multi-stage fine screen system 500.
On this basis, a segment removal cycle is formed: the bamboo joints and the hard blocks removed by the joint remover 300 enter the joint washer for cleaning, the coarse pulp obtained after the joint washer is cleaned enters the joint remover 300 again, and the remaining bamboo joints and hard blocks after the joint washer is cleaned enter the last steaming and boiling procedure again.
On this basis, a first filtrate cycle is formed: the filtrate of the fine screen washer 112 is heated to be used for cleaning the coarse pulp by the coarse screen washer 111, the filtrate generated after the coarse pulp is cleaned by the coarse screen washer 111 enters the filtrate tank 400 to be buffered, part of the filtrate in the filtrate tank 400 flows back, the coarse screen washer 111 is recycled, and the other part flows into the filtrate tank 400 of the coarse screen washer 111 to be used in the steaming system, the dilution of the jet cooker and the dilution of the section remover 300 in the previous working procedure.
As shown in fig. 2, the multi-section fine screening system 500 includes a buffering stand pipe 510, a first section fine screening device 520, a desander 530, a second section fine screening device 540, a third section fine screening device 550, a slag washer 560 and a dilution stand pipe 570, the first section fine screening device 520 screening outlet is connected with the pulp washing system, the first section fine screening device 520 screening outlet is connected with the desander 530, the desander 530 screening outlet is connected with the second section fine screening device 540, the second section fine screening device 540 screening outlet is connected with the first section fine screening device 520, the second section fine screening device 540 screening outlet is connected with the third section fine screening device 550, the third section fine screening device 550 screening outlet is connected with the second section fine screening device 540, the third section fine screening device 550 screening outlet is connected with the slag washer 560, the slag washer 560 screening outlet is connected with the third section fine screening device 550, and the filtrate outlet of the fine screening D0 section pulp washer 130 is connected with the dilution stand pipe 570.
The coarse pulp washed by the coarse screen pulp washer 111 is buffered by the buffer vertical pipe 510, then enters the primary fine screen device 520, and the primary good pulp screened by the primary fine screen device 520 enters the fine screen pulp washer 112 for washing.
On this basis, a first screening cycle is formed: the first-stage tail pulp screened by the first-stage fine screening device 520 enters the sand remover 530, the good pulp screened by the sand remover 530 enters the second-stage fine screening device 540, impurities screened by the sand remover 530 are discharged into a trench, and the second-stage good pulp screened by the second-stage fine screening device 540 enters the first-stage fine screening device 520.
On this basis, a second screening cycle was formed: the second-stage tailings screened by the second-stage fine screening device 540 enter the third-stage fine screening device 550, and the good slurry screened by the third-stage fine screening device 550 enters the second-stage fine screening device 540.
On this basis, a third screening cycle is formed: the tailings screened by the three-section fine screening device 550 enter a slag washer 560, the good slurry washed by the slag washer 560 enters the three-section fine screening device 550 again, and the impurities washed by the slag washer 560 are collected and discharged for treatment.
On this basis, a second filtrate cycle is formed: slurry needs to be diluted before entering the primary fine screening device 520, the sand remover 530, the secondary fine screening device 540 and the tertiary fine screening device 550, the fine screening pulp washer 112, the return pipe 160 and the dilution vertical pipe 570 are sequentially connected, the dilution vertical pipe 570 is simultaneously connected with the primary fine screening device 520, the sand remover 530, the secondary fine screening device 540 and the tertiary fine screening device 550, filtrate of the fine screening pulp washer 112 enters and is contained in the re-dilution vertical pipe 570 through the return pipe 160, and the dilution vertical pipe 570 provides dilution liquid for the primary fine screening device 520, the sand remover 530, the secondary fine screening device 540 and the tertiary fine screening device 550.
As shown in fig. 4, the slurry in the multi-fine screen system is pumped, and the transfer pump is omitted in fig. 2, and the primary fine screen apparatus 520, the secondary fine screen apparatus 540, and the tertiary fine screen apparatus 550 are all vibrating screens.
As shown in FIG. 1, the washing system further comprises an oxygen-stripping section washer, a D0 section washer 130, an EOP section washer 140 and a D1 section washer 150, wherein the washers in the washing system are all double-roll washers or vacuum washers, and the bleaching zone comprises an oxygen-stripping bleaching device 210, a buffer device, a D0 section bleaching device 230, an EOP section bleaching device 240, a D1 section bleaching device 250 and a pulping tower 260, and the fine screen washer 112, the oxygen-stripping bleaching device 210, the oxygen-stripping section washer, the D0 section bleaching device 230, the D0 section washer 130, the EOP section bleaching device 240, the EOP section washer 140, the D1 section bleaching device 250, the D1 section washer 150 and the pulping tower 260 are sequentially connected.
As shown in FIG. 3, the oxygen-stripping bleaching apparatus 210 comprises an oxygen-stripping and middle-concentrating vertical pipe 211, an oxygen-stripping and middle-concentrating pump 212, a first oxygen mixer 213, an oxygen pre-reaction pipe 214, an oxygen-stripping steam injector 215, a second oxygen mixer 216, an oxygen reaction tower 217 and an oxygen-stripping feeding pump 218 which are sequentially connected, the fine screen section pulp washer 110 is connected with the oxygen-stripping and middle-concentrating vertical pipe 211, the oxygen-stripping and middle-concentrating vertical pipe 211 is provided with a NaOH feeding port and a Mg (OH) 2 feeding port, and the first oxygen mixer 213 and the second oxygen mixer 216 can feed O 2 And mixing the slurry.
As shown in fig. 1, the oxygen-stripping washer comprises a first oxygen-stripping washer 121 and a second oxygen-stripping washer 122, wherein a steam inlet is arranged on the second oxygen-stripping washer 122; the buffer device comprises a pre-bleaching vertical pipe 221, a pre-bleaching feeding trough 222 and a pre-bleaching feeding pump 223, and the oxygen-stripping feeding pump 218, the first oxygen-stripping section pulp washer 121, the pre-bleaching vertical pipe 221, the pre-bleaching feeding trough 222, the pre-bleaching feeding pump 223 and the second oxygen-stripping section pulp washer 122 are sequentially connected.
As shown in FIG. 4, the D0 stage bleaching apparatus 230 comprises a D0 medium consistency riser 231 connected in sequenceThe second oxygen stripping section pulp washer 122 is connected with the D0 middle concentration vertical pipe 231, the D0 feeding pump 236 is connected with the D0 section pulp washer 130, and the D0 middle concentration vertical pipe 231 is provided with H 2 SO 4 The D0 mixer 234 is provided with ClO 2 And a charging port.
As shown in FIG. 5, the EOP stage bleaching apparatus 240 comprises an EOP medium consistency vertical pipe 241, an EOP medium consistency pump 242, an EOP mixer 243, an EOP reaction tower 244 and an EOP feeding pump 245 which are sequentially connected, the D0 stage pulp washer 130 is connected with the EOP medium consistency vertical pipe 241, the EOP feeding pump 245 is connected with the EOP stage pulp washer 140, and the EOP medium consistency vertical pipe 241 is provided with a steam inlet, a NaOH feeding port and H 2 O 2 Feed inlet, EOP mixer 243 discharges O 2 And mixing with the slurry.
As shown in FIG. 6, the D1 stage bleaching device 250 comprises a D1 medium concentration vertical pipe 251, a D1 medium concentration pump 252, a D1 mixer 253 and a D1 reaction tower 254 which are sequentially connected, the EOP stage pulp washer 140 is connected with the D1 medium concentration vertical pipe 251, the D1 reaction tower 254 is connected with the D1 stage pulp washer 150, the D1 medium concentration vertical pipe 251 is provided with a NaOH feeding port, and the D1 mixer 253 is provided with a ClO 2 The feeding port and the D1 section pulp washer 150 are provided with Na 2 S 2 O 3 And a charging port.
The redundant filtrate in the pulp washer in the pulp washing system is recycled by a circulating pump and is used for washing pulp for multiple times; steam can be introduced into the steam inlet.
The specific implementation steps are as follows:
1. the boiled slurry sequentially passes through a knot removing machine, a coarse screen pulp washing machine, a multi-section fine screen system and a fine screen pulp washing machine.
2. The slurry enters a wash bleaching system, and is washed and bleached back and forth between the wash system and the bleaching system, and the final slurry enters a pulping tower 260 for storage.
Example 2
Example 2 based on example 1: the desander comprises a slurry inlet pipe 531, a slurry outlet pipe 532, a frame 535 and a plurality of conical cyclones 533. As shown in fig. 7 and 8, the slurry inlet pipe 531 is disposed in parallel under the slurry outlet pipe 532, the slurry inlet pipe 531 and the slurry outlet pipe 532 are both connected to the frame body 535 by bolts, the plurality of conical cyclones 533 are uniformly distributed on two sides of the slurry inlet pipe 531 and the slurry outlet pipe 532, as shown in fig. 8, the plurality of conical cyclones 533 are arranged in a quincuncial manner in the horizontal direction, as shown in fig. 7, the plurality of conical cyclones 533 are arranged in a staggered manner in the vertical direction, the frame body 535 is provided with slag discharge grooves 536, the slag discharge grooves 536 are disposed below the conical cyclones 533, the two sides of the slurry inlet pipe 531 and the slurry outlet pipe 532 are both welded with connecting branch pipes 534, the connecting branch pipes 534 are both connected with the connecting branch pipes 534 on the side of the slurry inlet pipe 531, the upper ends of the conical cyclones 533 are both connected with the connecting branch pipes 534 on the side of the slurry outlet pipe 532, after one section of tail slurry enters the conical cyclones 533, the conical cyclones 533 enable the tail slurry to rotate at high speed, the lighter materials (good slurry) are discharged upwards through the upper discharge, and heavier materials (impurities and the like) are discharged downwards from the conical cyclone bottom along the inner wall of the slag discharge grooves under the action of centrifugal force.
The foregoing is merely exemplary of the present utility model, and specific technical solutions and/or features that are well known in the art have not been described in detail herein. It should be noted that, for those skilled in the art, several variations and modifications can be made without departing from the technical solution of the present utility model, and these should also be regarded as the protection scope of the present utility model, which does not affect the effect of the implementation of the present utility model and the practical applicability of the patent. The protection scope of the present application shall be subject to the content of the claims, and the description of the specific embodiments and the like in the specification can be used for explaining the content of the claims.
Claims (8)
1. The system for washing and rinsing the chemical pulp is characterized in that: the screening system comprises a section removing machine and a multi-section fine screening system, wherein the pulp washing system comprises a coarse screening section pulp washing machine and a fine screening section pulp washing machine, the section removing machine, the coarse screening section pulp washing machine, the multi-section fine screening system, the fine screening section pulp washing machine and the bleaching system are sequentially connected, a filtrate outlet of the coarse screening section pulp washing machine is connected with a cooking system in the previous working procedure, and a filtrate outlet of the fine screening section pulp washing machine is connected with the multi-section fine screening system.
2. The chemical pulp washing and bleaching system according to claim 1, wherein: the multistage fine screening system comprises a first stage fine screening device, a sand remover, a second stage fine screening device, a third stage fine screening device, a slag washer and a dilution vertical pipe, wherein a screening outlet of the first stage fine screening device is connected with the pulp washer, a screening outlet of the first stage fine screening device is connected with the sand remover, a screening outlet of the sand remover is connected with the second stage fine screening device, a screening outlet of the second stage fine screening device is connected with the first stage fine screening device, a screening outlet of the second stage fine screening device is connected with the third stage fine screening device, a screening outlet of the third stage fine screening device is connected with the slag washer, a screening outlet of the slag washer is connected with the third stage fine screening device, a filtrate outlet of the fine screening section pulp washer is connected with the dilution vertical pipe, and the dilution vertical pipe is simultaneously connected with the first stage fine screening device, the sand remover, the second stage fine screening device and the third stage fine screening device.
3. The chemical pulp washing and bleaching system according to claim 2, wherein: the sand remover comprises a pulp inlet pipe, a pulp outlet pipe and a plurality of conical cyclones, wherein the pulp inlet pipe is arranged right below the pulp outlet pipe in parallel, the lower ends of the conical cyclones are connected with the side surfaces of the pulp inlet pipe, and the upper ends of the conical cyclones are connected with the side surfaces of the pulp outlet pipe.
4. A chemical pulp washing and bleaching system according to claim 3, wherein: the pulp washing system further comprises a screening pulp washer, an oxygen-stripping section pulp washer, a D0 section pulp washer, an EOP section pulp washer, a D1 section pulp washer and a return pipe, wherein filtrate of the screening pulp washer can enter the dilution riser through the return pipe; the bleaching system comprises an oxygen-removing bleaching device, a D0 section bleaching device, an EOP section bleaching device and a D1 bleaching device, and the screening pulp washer, the oxygen-removing bleaching device, the oxygen-removing section pulp washer, the D0 section bleaching device, the D0 section pulp washer, the EOP section bleaching device, the EOP section pulp washer, the D1 bleaching device and the D1 section pulp washer are sequentially connected.
5. The chemical pulp washing and bleaching system according to claim 4, wherein: the oxygen-removing bleaching device comprises an oxygen-removing middle-concentration vertical pipe, a first oxygen mixer, an oxygen pre-reaction pipe and oxygen-removing steam which are connected in sequenceThe oxygen removal device comprises an ejector, a second oxygen mixer and an oxygen reaction tower, wherein a NaOH feed inlet and a Mg (OH) 2 feed inlet are arranged on an oxygen removal medium-concentration vertical pipe, and both the first oxygen mixer and the second oxygen mixer can be used for removing O 2 And mixing the slurry.
6. The chemical pulp washing and bleaching system according to claim 5, wherein: the oxygen-stripping section pulp washer comprises a first oxygen-stripping section pulp washer and a second oxygen-stripping section pulp washer, and a steam inlet is arranged on the second oxygen-stripping section pulp washer.
7. The chemical pulp washing and bleaching system according to claim 6, wherein: the D0 section bleaching device comprises a D0 medium-concentration vertical pipe, a D0 steam injector, a D0 mixer and a D0 reaction tower which are sequentially connected, wherein the D0 medium-concentration vertical pipe is provided with H 2 SO 4 The D0 mixer is provided with a ClO 2 A feed inlet; the EOP section bleaching device comprises an EOP middle-concentration vertical pipe, an EOP mixer and an EOP reaction tower which are sequentially connected, wherein the EOP middle-concentration vertical pipe is provided with a steam inlet, a NaOH feeding port and H 2 O charging port 2 The EOP mixer can mix O 2 Mixing with the slurry; the D1 bleaching device comprises a D1 medium-concentration vertical pipe, a D1 mixer and a D1 reaction tower which are sequentially connected, wherein the D1 medium-concentration vertical pipe is provided with a NaOH feeding port, and the D1 mixer is provided with ClO 2 And a charging port.
8. The chemical pulp washing and bleaching system according to claim 7, wherein: na is arranged on the D1 section pulp washer 2 S 2 O 3 And a charging port.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321708682.2U CN220520963U (en) | 2023-06-30 | 2023-06-30 | System for washing, selecting and bleaching chemical pulp |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202321708682.2U CN220520963U (en) | 2023-06-30 | 2023-06-30 | System for washing, selecting and bleaching chemical pulp |
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| CN220520963U true CN220520963U (en) | 2024-02-23 |
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| CN202321708682.2U Active CN220520963U (en) | 2023-06-30 | 2023-06-30 | System for washing, selecting and bleaching chemical pulp |
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| Country | Link |
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| CN (1) | CN220520963U (en) |
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