CN113074364A - System and method for treating fine slag generated by blending combustion and gasification of pulverized coal boiler - Google Patents
System and method for treating fine slag generated by blending combustion and gasification of pulverized coal boiler Download PDFInfo
- Publication number
- CN113074364A CN113074364A CN202110372558.2A CN202110372558A CN113074364A CN 113074364 A CN113074364 A CN 113074364A CN 202110372558 A CN202110372558 A CN 202110372558A CN 113074364 A CN113074364 A CN 113074364A
- Authority
- CN
- China
- Prior art keywords
- fine slag
- filter cake
- pulverized coal
- gasified fine
- gasified
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002893 slag Substances 0.000 title claims abstract description 142
- 239000003245 coal Substances 0.000 title claims abstract description 100
- 238000000034 method Methods 0.000 title claims abstract description 33
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 31
- 238000002309 gasification Methods 0.000 title claims abstract description 28
- 238000002156 mixing Methods 0.000 title claims description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 93
- 239000012065 filter cake Substances 0.000 claims abstract description 89
- 230000018044 dehydration Effects 0.000 claims abstract description 35
- 238000006297 dehydration reaction Methods 0.000 claims abstract description 35
- 238000001035 drying Methods 0.000 claims abstract description 33
- 239000000446 fuel Substances 0.000 claims abstract description 25
- 239000002002 slurry Substances 0.000 claims description 37
- 208000005156 Dehydration Diseases 0.000 claims description 34
- 238000003860 storage Methods 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 19
- 239000002699 waste material Substances 0.000 claims description 9
- 238000009826 distribution Methods 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 238000010438 heat treatment Methods 0.000 claims description 5
- 238000007599 discharging Methods 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 3
- 235000008733 Citrus aurantifolia Nutrition 0.000 abstract description 9
- 235000011941 Tilia x europaea Nutrition 0.000 abstract description 9
- 239000004571 lime Substances 0.000 abstract description 9
- 239000000463 material Substances 0.000 abstract description 6
- 238000003912 environmental pollution Methods 0.000 abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 abstract description 4
- 239000011148 porous material Substances 0.000 abstract description 4
- 239000004566 building material Substances 0.000 abstract description 2
- 239000012774 insulation material Substances 0.000 abstract description 2
- 230000004048 modification Effects 0.000 abstract description 2
- 238000012986 modification Methods 0.000 abstract description 2
- 239000002689 soil Substances 0.000 abstract description 2
- 230000002195 synergetic effect Effects 0.000 abstract description 2
- 238000009270 solid waste treatment Methods 0.000 abstract 1
- 239000004744 fabric Substances 0.000 description 18
- 238000003825 pressing Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 10
- 230000008901 benefit Effects 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 7
- 230000009467 reduction Effects 0.000 description 7
- 239000000706 filtrate Substances 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 5
- 238000009835 boiling Methods 0.000 description 5
- 230000005611 electricity Effects 0.000 description 5
- 239000003546 flue gas Substances 0.000 description 5
- 238000000227 grinding Methods 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- 241000196324 Embryophyta Species 0.000 description 4
- 230000009471 action Effects 0.000 description 4
- 239000006227 byproduct Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- 239000002390 adhesive tape Substances 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000013049 sediment Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 239000010866 blackwater Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000011038 discontinuous diafiltration by volume reduction Methods 0.000 description 2
- 239000003814 drug Substances 0.000 description 2
- 239000003517 fume Substances 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 238000012824 chemical production Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C7/00—Combustion apparatus characterised by arrangements for air supply
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23K—FEEDING FUEL TO COMBUSTION APPARATUS
- F23K1/00—Preparation of lump or pulverulent fuel in readiness for delivery to combustion apparatus
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23K—FEEDING FUEL TO COMBUSTION APPARATUS
- F23K3/00—Feeding or distributing of lump or pulverulent fuel to combustion apparatus
- F23K3/02—Pneumatic feeding arrangements, i.e. by air blast
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Processing Of Solid Wastes (AREA)
- Gasification And Melting Of Waste (AREA)
Abstract
The application relates to a system and a method for treating fine slag of pulverized coal boiler co-combustion gasification, comprising a feeding and drying device and a pulverized coal boiler device. After the gasified fine slag containing 70-99% of water enters the feeding drying device, deep dehydration is carried out until the fine slag filter cake containing 8-25% of water, a large amount of water resources are recovered, the received base heat value of the fine slag filter cake is obviously improved, the fine slag filter cake after most of water is removed presents a developed pore structure, the fine slag filter cake and fuel coal are mixed and combusted to present an obvious promotion synergistic effect, and the combustion characteristic of the gasified fine slag is obviously improved. The fine slag filter cake containing 8-25% of water enters a pulverized coal boiler device, carbon residue fuel in the fine slag filter cake is utilized to generate high-temperature high-pressure steam, and lime generated by combustion can be directly used as a heat insulation material, a building material, a road material, soil modification and the like. The gasification fine slag is dried and mixed, so that water, energy and efficiency are saved, and the problems of high difficulty in solid waste treatment of the gasification fine slag, serious environmental pollution and the like are solved.
Description
Technical Field
The invention relates to the field of coal chemical industry, in particular to a system and a method for treating fine slag of pulverized coal boiler co-combustion gasification.
Background
In the coal chemical production process, after entrained-flow bed gasification (coal water slurry gasification, dry coal powder gasification and the like) reaction, a large amount of gasified fine slag with high water content can be generated, and the content of combustible substances of dry bases of the gasified fine slag is 18-65%. The gasification fine slag has the discharge amount of about 6000 million tons to 1 hundred million tons every year, the gasification fine slag is mainly treated by a landfill mode at present, the volume reduction effect of the landfill mode is poor, water resources are wasted, a large amount of land resources are occupied, and secondary pollution is easily caused due to incomplete measures such as seepage prevention, scattering prevention and the like.
At present, the dewatering equipment for fine slag comprises: (1) and (4) a vacuum belt type or centrifugal filter, wherein the water content of the filter cake after dehydration is about 65%. The dehydration device has the problems of serious slurry leakage and leakage, serious environmental pollution, high transportation cost, large medicament consumption, serious water consumption of a system, short service life of filter cloth, frequent replacement and the like in the transportation process. (2) The water content of the filter cake after dehydration is about 50 percent. The dehydration device has the following problems: easy bonding of filter cake and filter cloth, large consumption of filter cloth, high working pressure and the like.
In view of this, the invention is particularly proposed.
Disclosure of Invention
The application provides a system and a method for treating gasified fine slag mixed in a circulating fluidized bed, which aim to solve the problems of high difficulty, serious environmental pollution and resource waste of the conventional gasified fine slag treatment.
In one aspect, the application provides a system for processing fine slag by blending and gasifying in a circulating fluidized bed, which comprises a feeding and drying device and a pulverized coal boiler device.
The feed drying device comprises: the system comprises a slurry pump, a drying machine, a belt conveyor, a storage bin and a pneumatic conveying blower.
The slurry pump is used for conveying the gasified fine slag to the drier.
One end of the belt conveyor is arranged below the drying machine, and the other end of the belt conveyor is connected with an inlet of the storage bin.
The feeding end of the pneumatic conveying fan is positioned below the storage bin, and the discharging end of the pneumatic conveying fan is communicated with the circulating fluidized bed boiler device.
In a second aspect, the present application provides a method for treating fine slag of pulverized coal boiler by blending combustion gasification, comprising the following steps:
and (3) inputting the gasified fine slag slurry into a drier through a slurry pump, and carrying out deep dehydration treatment on the gasified fine slag slurry by using the drier to obtain a gasified fine slag filter cake.
The gasified fine slag filter cake is conveyed to a storage bin and crushed by a belt conveyor and conveyed to a pulverized coal boiler device by a pneumatic conveying fan.
In a preferred embodiment of the invention, the process of carrying out deep dehydration treatment on the gasified fine slag slurry by using the drier to obtain the gasified fine slag filter cake comprises the following steps: conveying the gasified fine slag slurry to a drier through a slurry pump for squeezing; and heating the pressed gasified fine slag by a low-grade heat source until water in the gasified fine slag boils to obtain a gasified fine slag filter cake.
In the preferred embodiment of the invention, the low-grade heat source is the waste steam of a chemical plant at the temperature of 110-220 ℃ or low-pressure steam or high-temperature hot water.
In the preferred embodiment of the invention, a low-grade heat source is directly introduced into the drying machine.
In the preferred embodiment of the invention, the water content of the gasified fine slag filter cake is in the range of 8-25%.
In a third aspect, the application provides a method for blending gasified fine slag in a pulverized coal boiler, which comprises the step of adopting the pulverized coal boiler blending gasified fine slag system to combust a gasified fine slag filter cake obtained after dehydration by a drier and fuel coal in a storage bin in a pulverized coal boiler device.
In an alternative embodiment, the pulverized coal boiler plant has a lower burner, a middle burner and an upper burner.
The mixture of the gasified fine slag filter cake and the fuel coal is simultaneously sprayed into the pulverized coal boiler device through the lower layer burner, the middle layer burner and the upper layer burner.
Or the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into the pulverized coal boiler device through the lower-layer combustor, and then air distribution is optimized, so that the mixture is fully combusted.
Or the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into the pulverized coal boiler device through the middle burner layer burner, and then air distribution is optimized to realize the full combustion of the mixture.
In an optional embodiment, the method further comprises the step of optimally configuring combustion-supporting air of the combustor to enable the gasified fine slag filter cake and the fuel coal to be fully mixed and combusted.
The beneficial effect of this application includes:
the feeding and drying device used in the application dehydrates the water-containing gasified fine slag for the first time through the positive pressure of the slurry pump, and mainly can remove the gap water in the water-containing gasified fine slag; then, the second dehydration is carried out by mechanical pressing of a drying machine (similar to a plate-and-frame filter press), so that the capillary bound water can be mainly removed; then a heat source is input through a heat source pump, the filter cake is heated through indirect heat exchange, and is vacuumized through a vacuum pump, so that the boiling point of water is reduced, and the water in the filter cake is boiled and vaporized along with the water, thereby achieving the purpose of deep dehydration. The steam-water mixture pumped by the vacuum pump can pass through a condenser, after steam-water separation, liquid water is periodically discharged, tail gas is purified and discharged, so that the water content of a final filter cake is controlled to be 8-25%, and the problem that gasified fine slag is difficult to dewater can be completely solved. The technology integrates the advantages of mechanical pressing and low-boiling point gasification phase change, and adopts a low-grade heat source to achieve the purpose of deep dehydration and reduction.
The water content of the water-containing gasified fine slag is reduced to 8-25% by the feeding and drying device, which is beneficial to reduction and boiler co-combustion. Moreover, the feeding and drying device has simple equipment, easy manufacture and operation and strong adaptability to materials. Further mix the thin sediment system of burning of gasification through pulverized coal boiler and burn thin sediment filter cake of gasification and fuel coal, can save the raw coal, the circulation reuse of the energy of being convenient for has promoted energy utilization ratio, has avoided the waste of the energy.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic diagram of a feed drying apparatus provided herein;
FIG. 2 is a schematic structural diagram of a fine slag blending gasification system of a pulverized coal fired boiler provided by the present application.
Icon: 1-a slurry pump; 2-a vacuum pump; 3-a heat source pump; 4-a drier; 5-a belt conveyor; 6-a storage bin; 7-pulverized coal boiler plant.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. indicate an orientation or a positional relationship based on that shown in the drawings or that the product of the present invention is used as it is, this is only for convenience of description and simplification of the description, and it does not indicate or imply that the device or the element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.
Furthermore, the appearances of the terms "first," "second," and the like, if any, are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
It should be noted that the features of the embodiments of the present invention may be combined with each other without conflict.
The present application provides a system and method for treating fine slag in a pulverized coal fired boiler.
The water content of the coal gasification fine slag is high (70-99%), and the coal gasification fine slag is mainly processed in a landfill mode during treatment. The landfill mode volume reduction effect is poor, wastes water resource, and occupies a large amount of land resource, prevents osmosis, prevents measures such as raise and easily produces secondary pollution when incomplete.
The inventors have found that, in order to reduce the dehydration rate of the fine coal gasification slag, there are some cases of using a vacuum belt filter or a centrifugal filter and some cases of using a plate and frame filter press.
Wherein, the principle of adopting a vacuum belt type or centrifugal filter is as follows: the slurry is uniformly distributed on the filter cloth moving forwards by a feeding device, the filtrate passes through the filter cloth and the adhesive tape under the suction filtration action of the vacuum pump and enters the vacuum box, then enters the filtrate tank from a connecting pipeline at the lower part of the vacuum box, and the solid phase is retained on the filter cloth to form a filter cake. Because the gravity and the vacuum pumping direction are consistent, larger particles are deposited below the filter cake and small particles are deposited above the filter cake during deposition to form a filtration-assisting layer with a reasonable structure, the resistance is small, the filtration speed is high, and the formed filter cake moves along with the adhesive tape, is washed and dehydrated for multiple times and then falls off at the turning part of the filter cloth. The filter cloth and the adhesive tape are separated by the driving roller and are respectively cleaned and regenerated by water, and the filter cloth returns to the feed end again to start a new operation cycle after being adjusted by the deviation correcting device.
However, this approach has at least the following disadvantages: the water content of the filter cake after the dehydration of the vacuum belt filter is about 65 percent (namely the water content of the filter cake after the dehydration is still high); the slurry leakage and the liquid leakage are serious and the environmental pollution is serious in the transportation process; the transportation cost is high; the medicament consumption is large; the water consumption of the system is serious; the service life of the filter cloth is short, the filter cloth is frequently replaced, and the operation and maintenance cost is high; the equipment is of an open structure, the steam of a filter factory building is large, the wall surface of the filter factory building is seriously fallen after long-term operation, the ammonia smell in the factory building is heavier, and the equipment has great harm to the health of operators; the filter cake has high water content, which is not beneficial to reduction and boiler co-combustion.
The principle of adopting the plate-and-frame filter press is as follows: the filter plate is characterized in that the filter plate is formed by alternately arranging plates and frames, filter cloth covers two sides of the filter plate, and the plates and the frames are pressed by a pressing device, namely a filter pressing chamber is formed between the plates and the frames. The same position of the upper end and the middle of the plate and the frame is provided with small holes which form a channel after being compressed, the slag slurry pressurized to certain pressure enters a filter pressing chamber through the channel, the surface of the filter plate is carved with grooves, the lower end of the filter plate is drilled with a pore channel for discharging filtrate, and the filtrate is discharged out of a filter along the grooves and the pore channels through filter cloth under pressure, so that the slag slurry is dehydrated.
However, this approach has at least the following disadvantages: the water content of the filter cake after the dehydration of the plate-and-frame filter is about 50 percent (namely the water content of the filter cake after the dehydration is still high); the filter cake and the filter cloth are easy to bond; the working pressure is high, and the plate frame made of common materials is not pressure-resistant and is easy to break; the consumption of filter cloth is large; the unattended operation is difficult to achieve on site, the filter cloth needs to be cleaned manually, the workload is large, and potential safety hazards exist; the filter cake has high water content, which is not beneficial to reduction and boiler co-combustion.
In view of this, the inventor especially creatively proposes the following feed drying device.
Referring to fig. 1, the feeding and drying device includes a drying machine 4, and the drying machine 4 (for example, an inlet end of the drying machine 4) is connected to a slurry pump 1, a heat source pump 3 and a vacuum pump 2.
The water-containing gasified fine slag (the water content is 70-99 wt%) is pumped into a drier 4 through a slag slurry pump 1, and is mechanically squeezed by the drier 4 to form a filter cake, then the filter cake formed by the water-containing gasified fine slag in the drier 4 is heated under the action of a heat source input by a heat source pump 3, and the filter cake is vacuumized by a vacuum pump 2 to realize the dehydration process of the gasified fine slag.
As can be seen, the above dehydration comprises three stages:
the first stage is as follows: the water-containing gasified fine slag is dehydrated for the first time through the positive pressure of the slurry pump 1 in the process of being pumped into the drier 4;
and a second stage: the gasified fine slag after the first dehydration is dehydrated for the second time in a drier 4 through mechanical pressing of the drier 4;
and a third stage: and (3) heating the filter cake obtained after the second dehydration under the action of a heat source input by a heat source pump 3, and then vacuumizing by a vacuum pump 2 to perform third dehydration.
In an alternative embodiment, the feed pressure of the slurry pump 1 in the first stage can be, for example, 0 to 8MPa (e.g., 0MPa, 2MPa, 5MPa, or 8MPa, etc.). The pressing pressure in the second stage may be, for example, 0 to 8MPa (e.g., 0MPa, 2MPa, 5MPa, 8MPa, etc.).
In alternative embodiments, the temperature of the heat source used in the third stage may be 110-. Preferably, the heat source is a low grade heat source, such as waste steam or low pressure (e.g., 0.5MPa) steam or high temperature hot water from a chemical plant. And a low-grade heat source is adopted as a heat source, so that the cost is reduced, and the environment is protected.
The water content of the gasified fine slag filter cake obtained after the third dehydration is about 8-25 wt%.
It is worth to say that the inventor researches to find out that the water content in the gasified fine slag mainly includes four types:
(1) interstitial water, namely free water, which is easily removed by external mechanical pressure;
(2) capillary bound water, which is water bound by capillaries among particles, needs higher mechanical acting force and energy to be removed;
(3) surface adsorbed water, which is water covering the whole surface of the particles and adsorbed by the surface tension, and the water can be removed by air blowing;
(4) internally bound water, which is the most difficult to remove, requires high energy to evaporate the water for removal.
The feeding and drying device used in the application dehydrates the water-containing gasified fine slag for the first time through the positive pressure of the slurry pump 1, and mainly can remove the gap water in the water-containing gasified fine slag; then, the second dehydration is carried out through the mechanical pressing (similar to a plate and frame filter press) of the drying machine 4, so that the capillary bound water in the drying machine can be mainly removed; then a heat source is input through a heat source pump 3, the filter cake is heated through indirect heat exchange, and the vacuum pump 2 is used for vacuumizing to reduce the boiling point of water, so that the water in the filter cake is boiled and vaporized, and the purpose of deep dehydration is achieved. The steam-water mixture pumped out by the vacuum pump 2 can pass through a condenser, after steam-water separation, liquid water is periodically discharged, tail gas is discharged after purification treatment, so that the water content of a final filter cake is controlled to be 8-25%, and the problem that gasified fine slag is difficult to dewater can be completely solved. The technology integrates the advantages of mechanical pressing and low-boiling point gasification phase change, and adopts a low-grade heat source to achieve the purpose of deep dehydration and reduction.
The water content of the water-containing gasified fine slag is reduced to 8-25% by the feeding and drying device, which is beneficial to reduction and boiler co-combustion. Moreover, the feeding and drying device is simple, easy to manufacture and operate and strong in adaptability to materials.
Further, the inventor also provides a system and a method for treating the fine gasified slag mixed in the pulverized coal boiler.
Referring to fig. 2, the fine slag blending, burning and gasifying system of the pulverized coal boiler comprises a pulverized coal boiler device 7 and the feeding and drying device, wherein the pulverized coal boiler device 7 can be the pulverized coal boiler, a discharge port of the drying machine 4 is connected with a feed port of a storage bin 6, and a discharge port of the storage bin 6 is connected with the feed port of the pulverized coal boiler.
Further, one end of the belt conveyor 5 is arranged at the lower end of the discharge hole of the drying machine 4 or is directly connected with the discharge hole of the drying machine 4, and the other end of the belt conveyor is connected with the feed hole of the stock bin 6. The dehydrated gasified fine slag filter cake in the drier 4 is sent into a storage bin 6 through a belt conveyer 5.
The belt conveyor 5 may be a belt conveyor, and other conveying devices having similar functions may be used. The conveying efficiency of the gasified fine slag filter cake can be greatly improved through the belt conveyor, the labor is saved, and the processing time is shortened.
Correspondingly, the method for blending and burning the gasified fine slag in the pulverized coal boiler adopts the system, and the gasified fine slag filter cake obtained by dehydration of the feeding and drying device and the fuel coal in the bunker 6 are burned in the pulverized coal boiler.
In an optional embodiment, the fine slag blending and gasifying system of the pulverized coal boiler further comprises a grinding device, and the grinding device is arranged between the storage bin 6 and the pulverized coal boiler.
Before the gasified fine slag filter cake and the fuel coal enter the pulverized coal boiler, the blocky filter cake and the coal are ground by a grinding device. The above-mentioned substances may be, by reference, ground to a particle size of 20 to 200. mu.m.
In an alternative embodiment, a pneumatic conveying fan may be further provided between the feeding port of the pulverized coal boiler unit 7 and the discharging port of the milling unit to rapidly convey the milled material into the pulverized coal boiler.
The levigation device and the pneumatic conveying fan can be arranged at the bottom (lower part) of the storage bin 6.
In an alternative embodiment, the pulverized coal boiler in the present application has a lower burner, a middle burner and an upper burner. The specific structure of the pulverized coal boiler can refer to the prior art, and is not described in detail herein.
In this application, the fine sediment filter cake of gasification mixes burns and gets into pulverized coal fired boiler internal combustion accessible following four kinds of modes and carries out:
(1) the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into the pulverized coal boiler through the lower layer burner, the middle layer burner and the upper layer burner at the same time;
(2) the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into a pulverized coal boiler through a lower-layer burner, and then air distribution is optimized to realize the full combustion of the mixture;
(3) the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into a pulverized coal boiler through a middle burner layer burner, and then air distribution is optimized to realize the full combustion of the mixture;
(4) and (2) on the basis of (1), optimizing the configuration of combustion-supporting air of a combustor to ensure that the gasified fine slag filter cake and the fuel coal are fully mixed and combusted.
The combustion products contain lime fume and unburned gasified fine slag filter cake, and byproduct steam is generated.
Products after combustion can be separated through a separation unit, and the obtained unburned gasified fine slag filter cake downwards enters the combustion chamber again through the return pipe for circular combustion; the obtained lime-containing flue gas upwards sequentially passes through the high-temperature heat exchange unit and the low-temperature heat exchange unit to obtain a byproduct, namely high-temperature and high-pressure steam; the cooled lime enters an ash hopper, and the cooled flue gas enters a chimney through a smoke exhaust fan for standard emission after being purified by a purification and dust removal unit.
The process facilitates the recycling of energy, improves the energy utilization rate and avoids the waste of energy.
In summary, the method for blending and burning gasified fine slag in the pulverized coal boiler provided by the application at least has the following effects: through the reduction of filter cakes, the landfill storage capacity of a slag site is greatly reduced, the water used by the whole system is saved by recovering the filtrate, the electricity is saved, and the social benefit is realized; the filter cake is environment-friendly and loaded, no slurry leakage and liquid leakage exist, the field environment is good, and the environment-friendly benefit is realized; after the water content is reduced to 8-25%, the coal is conveyed to a boiler for blending combustion, so that raw coal can be saved, the transportation cost is reduced, and economic benefits are realized; the process can be controlled fully automatically, and the safety benefit is realized by starting and stopping the device by one key.
In conclusion, the method for blending and burning gasified fine slag in the pulverized coal boiler can realize water saving, environmental protection and recycling of waste solids in the whole process.
Example 1
Referring to fig. 2, the present embodiment provides a fine slag blending and gasifying system for a pulverized coal boiler, which includes: a slurry pump, a drier, a belt conveyer 5, a grinding device, a storage bin 6, a pneumatic conveying fan and a pulverized coal boiler device 7.
The inlet end of the drier 4 is respectively connected with the slurry pump 1, the heat source pump 3 and the vacuum pump 2.
The pulverized coal boiler device 7 is a pulverized coal boiler, one end of the belt conveyor 5 is arranged at the lower end of the discharge hole of the drier 4 or is directly connected with the discharge hole of the drier 4, and the other end of the belt conveyor is connected with the feed hole of the storage bin 6. The levigating device is arranged between the stock bin 6 and the pulverized coal boiler, and the pneumatic conveying fan is arranged between a feed inlet of the pulverized coal boiler device 7 and a discharge outlet of the levigating device.
Example 2
The embodiment provides a fine slag blending and gasification method for a pulverized coal boiler, which is implemented by adopting the fine slag blending and gasification system for the pulverized coal boiler provided in the embodiment 1 according to the following steps:
s100: inputting the gasified fine slag slurry into a drier 4 through a slurry pump 1;
s200: the drier 4 carries out deep dehydration treatment on the gasified fine slag slurry to obtain a gasified fine slag filter cake;
more specifically, dehydration comprises three stages:
the first stage is as follows: the water-containing gasified fine slag is dehydrated for the first time through the positive pressure of the slurry pump 1 in the process of being pumped into the drier 4;
and a second stage: the gasified fine slag after the first dehydration is dehydrated for the second time in a drier 4 through mechanical pressing of the drier 4;
and a third stage: and (3) heating the filter cake obtained after the second dehydration under the action of a heat source input by a heat source pump 3, and then vacuumizing by a vacuum pump 2 to perform third dehydration.
And heating the pressed gasified fine slag by a low-grade heat source, boiling the water in the heated gasified fine slag, controlling the water content of a final gasified fine slag filter cake to be 8-25%, and completely solving the problem that the gasified fine slag is difficult to dehydrate.
Wherein, the feeding pressure of the slurry pump 1 in the first stage is 8MPa, and the squeezing pressure in the second stage is 8 MPa. The heat source used in the third stage is hot water at a temperature of 150 ℃.
S300: conveying the gasified fine slag filter cake to a pulverized coal boiler device 7 through a belt conveyor;
more specifically, the gasified fine slag filter cake is conveyed into a storage bin 6 through a belt conveyor, mixed with fuel coal in the storage bin 6, then ground to the particle size of 20-200 μm through a grinding device, and then conveyed into a pulverized coal boiler through a pneumatic conveying blower.
S400: and simultaneously spraying the mixture of the gasified fine slag filter cake and the fuel coal into the pulverized coal boiler through the lower layer burner, the middle layer burner and the upper layer burner for high-temperature combustion to obtain a combustion product containing lime fume and the unburned gasified fine slag filter cake, and simultaneously generating byproduct steam.
S500: the products after combustion are separated by a separation unit (not shown in the figure), and unburnt gasified fine slag filter cakes are obtained and downwards enter the combustion chamber again through a return pipe (not shown in the figure) for circular combustion; the obtained lime-containing flue gas upwards passes through a high-temperature heat exchange unit (not shown) and a low-temperature heat exchange unit (not shown) in sequence to obtain a byproduct, namely high-temperature and high-pressure steam; the cooled lime enters an ash hopper (not shown), and the cooled flue gas enters a chimney (not shown) through a flue gas exhaust fan (not shown) for standard emission after being purified by a purifying and dedusting unit (not shown).
Test examples
And (3) dehydrating and drying gasified black water:
the water content of the gasified black water is 75-99%, and the current dewatering device can dewater to 50% and directly transport to a landfill site. According to the gasification furnace with the gas production rate of 12 ten thousand cubic meters per hour, the dry basis (absolutely dry and water-free) amount of gasified fine slag is 6 ten thousand tons every year, and the carbon residue is calculated according to the average value of 30 percent:
A. the total production cost is as follows:
1. the operating cost of the current vacuum belt filter (the water content of a filter cake is 50 percent):
(1) raw material and fuel power
2016000kwh of electricity is consumed in the year, the unit price is 0.38 yuan/kwh, and the annual electricity charge is 76.6 ten thousand yuan;
160000m of filter cloth washing water consumed in year3Monovalent 2.98 yuan/m3The annual filter cloth washing water cost is 47.68 ten thousand yuan;
③ the annual transportation volume is 12 ten thousand tons, the unit price is 40 yuan/ton (according to the lowest price), and the annual transportation cost and the landfill cost are 480 ten thousand yuan;
the total production cost is 604.28 ten thousand yuan.
2. The pulverized coal boiler after the fine slag blending gasification technology of the embodiment 2 of the application is adopted has the following operation cost (25 percent of filter cake water):
(1) raw material and fuel power
5328 tons of low-pressure steam, 75 yuan per ton, and 39.96 ten thousand yuan per year;
41025m of regenerated water consumed in year3Monovalent of 5.65 yuan/m3Annual regeneration water cost 23.18 ten thousand yuan;
consumption of circulating cooling water 532800m3Monovalent 0.2 yuan/m3Annual circulating cooling water running cost is 10.66 ten thousand yuan (the price of the circulating cooling water is 2.98 yuan, but the circulating water is recycled, and the running cost is only 0.2 yuan/m3)；
Year consumption of compressed air 79920m3Monovalent 0.44 yuan/Nm3Annual compressed air cost 3.52 ten thousand yuan;
electricity consumption is 720000kwh year by year, the unit price is 0.38 yuan/kwh, and the annual electricity charge is 27.36 ten thousand yuan;
the above 5 items add up to 104.68 ten thousand yuan.
(2) The water content of the filter cake is reduced from 50 percent to 25 percent, 4 ten thousand tons of filtrate are recovered more than one year, the unit price is 2.98 yuan/ton, and 11.92 yuan is saved every year.
The total production cost is 92.76 ten thousand yuan.
That is, the annual operating cost of the vacuum belt filter is 604.28 ten thousand yuan, and the annual operating cost of the pulverized coal boiler after the pulverized coal boiler mixed-burning gasification fine slag technology of the embodiment 2 of the application is 92.76 ten thousand yuan, so that compared with the vacuum belt filter, the annual cost of the liquid-carrying waste solid deep dehydration drying complete set of technical equipment is 511.52 ten thousand yuan.
B. Transportation fee, landfill fee, and storage capacity increase fee of landfill
The technology of the application: the annual transportation capacity is 8 ten thousand tons, the unit price is 40 yuan/ton (according to the lowest price), and the annual transportation cost and the landfill cost are 320 ten thousand yuan;
the prior art is as follows: the gasified fine slag is dehydrated and then is called as gasified filter cake in the general industry, and the water content of the gasified filter cake dehydrated to 50 percent is high, so that the gasified filter cake can not enter a boiler. If the owner does not have a boiler and does not want to be a new incinerator and also wants to fill up the gasified filter cake with dewatering to 25%, the transportation and landfill cost is increased by 320 ten thousand per year on the basis of the operation cost of the technology of the application.
C. Economic benefit of gasifying filter cake incineration
The gasified filter cake has water content of 25 percent and carbon residue content of 30 percent, the annual output gasified filter cake is 8 ten thousand tons, and the annual output high-temperature high-pressure steam quantity of the incinerator is 14.5 ten thousand tons. Calculated according to 100 yuan/ton of steam, the annual benefit is increased by about 1450 ten thousand yuan, and the lime after the mixed burning of the technology can also generate certain economic value for external sale.
In conclusion, the gasified fine slag containing 70-99% of water is converted into the fine slag filter cake containing 8-25% of water after entering the gasification fine slag dewatering equipment, a large amount of water resources are recovered, and the received base heat value of the fine slag filter cake is obviously improved. After most of water is removed, the gasified fine slag presents a developed pore structure, the mixed combustion of the gasified fine slag and the fuel coal presents a remarkable synergistic effect, and the combustion characteristic of the gasified fine slag is remarkably improved. The fine slag filter cake containing 8-25% of water enters a fine slag blending and gasifying system of a pulverized coal boiler, carbon residue fuel in the fine slag filter cake is utilized to generate high-temperature and high-pressure steam, and lime generated by combustion can be directly used as a heat insulation material, a building material, a road material, soil modification and the like. The method realizes the effects of water saving, energy saving and efficiency improvement, and solves the industry bottleneck problems of high difficulty in treating the gasified fine slag solid waste and serious environmental pollution.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. A processing system for blending, burning and gasifying fine slag of a pulverized coal boiler is characterized by comprising a feeding and drying device and a pulverized coal boiler device;
the feed drying device comprises: a slurry pump, a drying machine, a belt conveyor, a storage bin and a pneumatic conveying blower;
the slurry pump is used for conveying the gasified fine slag to the drier;
one end of the belt conveyor is arranged below the drying machine, and the other end of the belt conveyor is connected with an inlet of the storage bin;
the feeding end of the pneumatic conveying fan is positioned below the storage bin, and the discharging end of the pneumatic conveying fan is communicated with the pulverized coal boiler device.
2. A method for treating fine slag of pulverized coal boiler by blending combustion gasification, which is characterized by comprising the following operations by using the treatment system of claim 1:
inputting the gasified fine slag slurry into the drier through the slag slurry pump, and carrying out deep dehydration treatment on the gasified fine slag slurry by using the drier to obtain a gasified fine slag filter cake;
and conveying the gasified fine slag filter cake to the storage bin through the belt conveyor, crushing the gasified fine slag filter cake, and conveying the gasified fine slag filter cake to a pulverized coal boiler device by using a pneumatic conveying fan.
3. The method for treating the gasified fine slag according to claim 2, wherein the step of performing deep dehydration treatment on the gasified fine slag slurry by using the drier to obtain a gasified fine slag filter cake comprises the following steps:
conveying the gasified fine slag slurry to the drier through the slag slurry pump for squeezing;
and heating the pressed gasified fine slag by using a low-grade heat source until the water in the gasified fine slag boils to obtain the gasified fine slag filter cake.
4. The method for treating the gasified fine slag according to claim 3, wherein the low-grade heat source is the waste steam of a chemical plant at 110-220 ℃ or low-pressure steam or high-temperature hot water.
5. The method for treating the gasified fine slag according to claim 3, wherein the low-grade heat source is directly introduced into the drier.
6. The method according to claim 3, wherein the water content of the cake of gasified fine slag is in the range of 8 to 25%.
7. The method for blending gasified fine slag of the pulverized coal boiler is characterized in that the pulverized coal boiler blending gasified fine slag system of claim 1 is adopted, and a gasified fine slag filter cake obtained after dehydration by the drier and fuel coal in the storage bin are combusted in the pulverized coal boiler device.
8. The method of claim 7, wherein the pulverized coal boiler plant has a lower layer burner, a middle layer burner, and an upper layer burner;
the mixture of the gasified fine slag filter cake and the fuel coal is simultaneously sprayed into the pulverized coal boiler device through the lower layer burner, the middle layer burner and the upper layer burner;
or the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into the pulverized coal boiler device through the lower-layer burner, and then air distribution is optimized to realize the full combustion of the mixture;
or the mixture of the gasified fine slag filter cake and the fuel coal is sprayed into a pulverized coal boiler device through the layer burner of the middle layer burner, and then air distribution is optimized to realize the full combustion of the mixture;
preferably, the method further comprises the step of optimally configuring combustion-supporting air of the combustor to enable the gasified fine slag filter cake and the fuel coal to be fully mixed and combusted.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110372558.2A CN113074364A (en) | 2021-04-07 | 2021-04-07 | System and method for treating fine slag generated by blending combustion and gasification of pulverized coal boiler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110372558.2A CN113074364A (en) | 2021-04-07 | 2021-04-07 | System and method for treating fine slag generated by blending combustion and gasification of pulverized coal boiler |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113074364A true CN113074364A (en) | 2021-07-06 |
Family
ID=76615296
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110372558.2A Pending CN113074364A (en) | 2021-04-07 | 2021-04-07 | System and method for treating fine slag generated by blending combustion and gasification of pulverized coal boiler |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113074364A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113566230A (en) * | 2021-08-03 | 2021-10-29 | 西安热工研究院有限公司 | Method and system for realizing direct blending combustion and gasification of fine slag in pulverized coal fired boiler |
| CN114669233A (en) * | 2022-04-20 | 2022-06-28 | 北京干雾科技有限公司 | Device and method for mixed utilization of pebble coal and coal gasification fine slag |
| CN114749098A (en) * | 2022-05-05 | 2022-07-15 | 江苏天煜通环保科技有限公司 | System and method for coupling granulation of gasified fine slag and sludge |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102211845A (en) * | 2010-04-08 | 2011-10-12 | 北京朗新明环保科技有限公司 | Sludge treatment and disposal system and method |
| CN203683345U (en) * | 2014-01-22 | 2014-07-02 | 桂林理工大学 | System for drying domestic sludge by using afterheat of dry process cement kiln and carrying out direct blending combustion treatment |
| CN106322404A (en) * | 2016-09-05 | 2017-01-11 | 上海理工大学 | Sludge and coal fluidization-suspension coupled combustion system based on direct blowing type high-temperature flue gas drying |
| CN111117708A (en) * | 2020-01-21 | 2020-05-08 | 恒力石化（大连）炼化有限公司 | Coal water slurry gasification fine ash treatment system and process |
| CN111392811A (en) * | 2020-03-04 | 2020-07-10 | 中国矿业大学 | Multi-energy-field synergistic efficient dehydration method for coal gasification fine slag black water of entrained flow bed |
| CN111594829A (en) * | 2020-06-17 | 2020-08-28 | 中国华能集团清洁能源技术研究院有限公司 | Circulating fluidized bed boiler tar slag blending burning system and working method thereof |
-
2021
- 2021-04-07 CN CN202110372558.2A patent/CN113074364A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102211845A (en) * | 2010-04-08 | 2011-10-12 | 北京朗新明环保科技有限公司 | Sludge treatment and disposal system and method |
| CN203683345U (en) * | 2014-01-22 | 2014-07-02 | 桂林理工大学 | System for drying domestic sludge by using afterheat of dry process cement kiln and carrying out direct blending combustion treatment |
| CN106322404A (en) * | 2016-09-05 | 2017-01-11 | 上海理工大学 | Sludge and coal fluidization-suspension coupled combustion system based on direct blowing type high-temperature flue gas drying |
| CN111117708A (en) * | 2020-01-21 | 2020-05-08 | 恒力石化（大连）炼化有限公司 | Coal water slurry gasification fine ash treatment system and process |
| CN111392811A (en) * | 2020-03-04 | 2020-07-10 | 中国矿业大学 | Multi-energy-field synergistic efficient dehydration method for coal gasification fine slag black water of entrained flow bed |
| CN111594829A (en) * | 2020-06-17 | 2020-08-28 | 中国华能集团清洁能源技术研究院有限公司 | Circulating fluidized bed boiler tar slag blending burning system and working method thereof |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113566230A (en) * | 2021-08-03 | 2021-10-29 | 西安热工研究院有限公司 | Method and system for realizing direct blending combustion and gasification of fine slag in pulverized coal fired boiler |
| CN113566230B (en) * | 2021-08-03 | 2023-08-22 | 西安热工研究院有限公司 | Method and system for realizing direct blending combustion gasification fine slag of pulverized coal boiler |
| CN114669233A (en) * | 2022-04-20 | 2022-06-28 | 北京干雾科技有限公司 | Device and method for mixed utilization of pebble coal and coal gasification fine slag |
| CN114749098A (en) * | 2022-05-05 | 2022-07-15 | 江苏天煜通环保科技有限公司 | System and method for coupling granulation of gasified fine slag and sludge |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113074364A (en) | System and method for treating fine slag generated by blending combustion and gasification of pulverized coal boiler | |
| US3977947A (en) | Fluidized bed carbonization | |
| CN205606576U (en) | Recoverable industry waste product incineration disposal device of ash material | |
| CN104261451B (en) | A kind of production method of light calcium carbonate | |
| CN211170408U (en) | Sludge mixing drying pure combustion power generation system | |
| CN207659297U (en) | Sludge drying couples coal generating system | |
| CN106224997A (en) | The Combined type pulverizing system generated electricity for coal and mud coupling combustion | |
| CN112728550A (en) | Treatment system and method for directly burning gasified fine slag | |
| CN110721983A (en) | Method for treating garbage by adopting ball mill | |
| CN207471565U (en) | Utilize the coal slime of boiler low-temperature fume cycle, drying sludge conveying and combustion system | |
| CN113929276B (en) | Treatment method of coal gasification sludge and coal gasification production method | |
| CN113028418A (en) | Treatment system and method for blending-burning gasified fine slag of circulating fluidized bed boiler | |
| Murko et al. | The creation of a low-capacity boiler plant on coal-enrichment waste | |
| CN110283630A (en) | Coal chemical industry solid waste treatment device and treatment method | |
| RU130312U1 (en) | COMPLEX FOR PROCESSING BROWN COAL AND COAL WASTE | |
| CN111533426A (en) | Sludge drying and dewatering equipment and method | |
| CN215627560U (en) | Sludge drying system | |
| CN102863137B (en) | Comprehensive utilization method and comprehensive utilization system for biochemical sludge | |
| CN204176667U (en) | The coal of fan mill powder process and the green electricity generation system of coal slime multifuel combustion | |
| CN204039334U (en) | Coal gas circulation coal wholegrain radial sector pyrolysis coupling Active coke preparation system | |
| CN110567261B (en) | Gasification ash drying device and method of four-nozzle water gas type entrained flow bed | |
| RU2241904C1 (en) | Complex for processing solid fuel on bioresources base and producing thermal energy | |
| CN113149394A (en) | Multistage sludge drying system and drying method thereof | |
| CN112723687A (en) | Sludge treatment system | |
| CN201737900U (en) | High-efficiency quick coal pyrolyzing device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210706 |