CN116422226A - Closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery - Google Patents
Closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery Download PDFInfo
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- CN116422226A CN116422226A CN202310471831.6A CN202310471831A CN116422226A CN 116422226 A CN116422226 A CN 116422226A CN 202310471831 A CN202310471831 A CN 202310471831A CN 116422226 A CN116422226 A CN 116422226A
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- 239000007789 gas Substances 0.000 title claims abstract description 282
- 238000011084 recovery Methods 0.000 title claims abstract description 146
- AOBXGGAGUYYNQH-UHFFFAOYSA-N ammonium sulfate urea Chemical compound [NH4+].[NH4+].NC(N)=O.[O-]S([O-])(=O)=O AOBXGGAGUYYNQH-UHFFFAOYSA-N 0.000 title claims abstract description 134
- 239000002918 waste heat Substances 0.000 title claims abstract description 56
- 238000005469 granulation Methods 0.000 title claims abstract description 35
- 230000003179 granulation Effects 0.000 title claims abstract description 35
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 46
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 30
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 23
- 238000005243 fluidization Methods 0.000 claims description 52
- 238000001704 evaporation Methods 0.000 claims description 44
- 230000008020 evaporation Effects 0.000 claims description 44
- 239000007788 liquid Substances 0.000 claims description 37
- 239000000428 dust Substances 0.000 claims description 36
- 239000002245 particle Substances 0.000 claims description 33
- 239000000047 product Substances 0.000 claims description 26
- 239000004202 carbamide Substances 0.000 claims description 21
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 18
- 238000002156 mixing Methods 0.000 claims description 17
- 229910052921 ammonium sulfate Inorganic materials 0.000 claims description 16
- 239000008187 granular material Substances 0.000 claims description 16
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 claims description 13
- 235000011130 ammonium sulphate Nutrition 0.000 claims description 13
- 238000004519 manufacturing process Methods 0.000 claims description 9
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 claims description 8
- 238000000889 atomisation Methods 0.000 claims description 8
- 239000000843 powder Substances 0.000 claims description 8
- 239000013078 crystal Substances 0.000 claims description 3
- 239000012467 final product Substances 0.000 claims description 3
- 239000000463 material Substances 0.000 claims description 3
- 238000003860 storage Methods 0.000 claims description 3
- XBTRXGPECITWFW-UHFFFAOYSA-L NC(=O)N.S(=O)(=O)([O-])[O-].[Na+].[Na+] Chemical compound NC(=O)N.S(=O)(=O)([O-])[O-].[Na+].[Na+] XBTRXGPECITWFW-UHFFFAOYSA-L 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 claims 2
- 239000002994 raw material Substances 0.000 claims 2
- 230000008901 benefit Effects 0.000 abstract description 21
- 230000007613 environmental effect Effects 0.000 abstract description 9
- 239000000243 solution Substances 0.000 description 43
- 238000004064 recycling Methods 0.000 description 23
- 238000000034 method Methods 0.000 description 18
- 238000001816 cooling Methods 0.000 description 7
- 230000001502 supplementing effect Effects 0.000 description 6
- 238000009833 condensation Methods 0.000 description 5
- 230000005494 condensation Effects 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 239000001166 ammonium sulphate Substances 0.000 description 4
- 238000005507 spraying Methods 0.000 description 3
- 239000013589 supplement Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 239000000498 cooling water Substances 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 239000003337 fertilizer Substances 0.000 description 2
- 239000002440 industrial waste Substances 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 230000037390 scarring Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000002351 wastewater Substances 0.000 description 2
- 238000004891 communication Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000000618 nitrogen fertilizer Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
- B01J2/16—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by suspending the powder material in a gas, e.g. in fluidised beds or as a falling curtain
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Fertilizers (AREA)
Abstract
The invention provides a closed-cycle ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery, which comprises a feeding system, a granulation system, a tail gas waste heat recovery system, a tail gas closed-cycle system and an ammonium sulfate urea solution recovery system. The closed circulation urea ammonium sulfate fluidized bed granulation system with the tail gas waste heat recovery, disclosed by the invention, has the advantages that the tail gas closed circulation system recovers ammonia to the maximum extent, meanwhile, dust-free and ammonia-containing tail gas emission is realized, and great economic and environmental benefits are realized; the tail gas waste heat recovery system realizes tail gas waste heat recovery, reduces the consumption of steam and circulating water, and has certain economic benefit and environmental benefit.
Description
Technical Field
The invention belongs to the technical field of production of ammonium sulfate urea, and particularly relates to a closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery.
Background
The ammonium sulfate urea product is widely applied to crops, can be used as a base fertilizer for the crops and can also be used as an additional fertilizer for the crops, and is a high-efficiency nitrogen fertilizer. One key technology in the production of ammonium sulfate urea products is the fluidized bed granulation treatment of ammonium sulfate urea, i.e. the production of a mixed solution of 96 wt% urea solution and ammonium sulfate into an ammonium sulfate urea product (water content about 0.5 wt%). Through research and study on domestic urea production companies, the problems that tail gas discharged in the current domestic urea fluidized bed granulation contains dust, ammonia, and tail gas waste heat cannot be recovered are found.
Summary of the invention
In view of the above, the invention aims to provide a closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery, so as to overcome the defects of the prior art and solve the problems of dust-containing tail gas emission, ammonia-containing tail gas emission, incapability of recovering tail gas waste heat and the like.
In order to achieve the above purpose, the technical scheme of the invention is realized as follows:
the closed circulation ammonium sulfate urea fluidized bed granulation system with the tail gas waste heat recovery comprises a feeding system, a granulation system, a tail gas waste heat recovery system, a tail gas closed circulation system and an ammonium sulfate urea solution recovery system;
further, the feeding system comprises an ammonium sulfate urea mixing tank, a stirrer, an ammonium sulfate urea heater and an ammonium sulfate urea feeding pump; the granulating system comprises a granulator, a first cooler, a fluidization fan, an atomizing blower, an atomizing air heater, a fluidization air heater, a vibrating screen, a circulating bucket elevator, a product bucket elevator, a final cooler and a cyclone separator; the tail gas waste heat recovery system comprises a recovered gas cooler, a recovered gas heater and a circulating pump; the tail gas closed circulation system comprises a recovered gas condensing tower, a recovered gas dedusting tower, a circulating cooler, a recovered gas condensing tower circulating pump and a recovered gas dedusting tower circulating pump; the ammonium sulfate urea solution recovery system comprises a recovery tank, a circulating solution pump, an evaporation heater, an evaporation separator and an evaporation condenser;
further, an inlet of the ammonium sulfate urea mixing tank is provided with 27 wt% of aluminum sulfate solution feed, 96 wt% of urea solution feed, an evaporation separator and a stirrer, and an outlet of an ammonium sulfate urea feed pump is connected with a granulator of a granulating system;
further, a feed inlet of the granulator is connected with an ammonium sulfate urea feed pump, an air inlet is connected with an atomization air heater and a fluidization air heater, a discharge outlet of the granulator is connected with a first cooler, an air outlet of the granulator is connected with a cyclone separator, the discharge outlet of the cyclone separator returns to the first cooler, and the air outlet of the cyclone separator is connected with a recovery gas cooler of a tail gas waste heat recovery system; an air inlet of the atomizing blower is connected with a recovery air heater of the tail gas waste heat recovery system, an air outlet of the atomizing blower is connected with an atomizing air heater, and an air outlet of the atomizing air heater is connected with the granulator; the air inlet of the fluidization fan is connected with a recovery air heater of the tail gas waste heat recovery system, the air outlet of the fluidization fan is connected with a fluidization air heater and a first cooler, and the air outlet of the fluidization air heater is connected with the granulator; the discharge port of the first cooler is connected with a vibrating screen, the discharge port of the vibrating screen is connected with a circulating bucket elevator and a product bucket elevator, the discharge of the circulating bucket elevator returns to the granulator, the discharge port of the product bucket elevator is connected with a final cooler, and the outlet of the final cooler is the ammonium sulfate urea product;
further, an air inlet of the recovered gas cooler is connected with a cyclone separator, an air outlet of the recovered gas cooler is connected with a recovered gas condensing tower, an air inlet of the recovered gas heater is connected with a recovered gas dust removing tower, an air outlet of the recovered gas heater is connected with a fluidization fan and an atomization blower, and a circulating pump is used for connecting the recovered gas cooler and the recovered gas heater into a closed circulating system;
further, the bottom of the recovery gas condensing tower is connected with a recovery gas condensing tower circulating pump, the recovery gas condensing tower circulating pump is connected with a circulating cooler, the recovery gas dedusting tower is connected with a recovery gas condensing tower, the bottom of the recovery gas dedusting tower is connected with a recovery gas dedusting tower circulating pump, and an air outlet of the recovery gas dedusting tower is connected with a recovery gas heater of the tail gas waste heat recovery system;
further, an inlet of the recovery tank is connected with the recovery gas condensing tower, an outlet of the recovery tank is connected with the circulating solution pump, an outlet of the circulating solution pump is connected with the evaporation heater, a discharge hole of the evaporation heater is connected with the evaporation separator, a liquid outlet of the evaporation separator is connected with the ammonium sulfate urea mixing tank, an air outlet of the evaporation separator is connected with the evaporation condenser, and a liquid outlet of the evaporation condenser returns to the recovery gas condensing tower;
further, 27% wt of aluminum sulfate solution is used as a granulating additive, so as to inhibit dust generation in the granulating process, inhibit scarring of the granulator and prolong the cleaning period of the granulator; fully mixing the ammonium sulfate powder and the heated molten urea in a stirrer to ensure that the ammonium sulfate powder is completely dissolved in the urea solution;
further, the air outlet of the atomizing blower is heated to 140 ℃ by an atomizing air heater, and then an auxiliary liquid nozzle atomizes the ammonium sulfate urea solution conveyed by the ammonium sulfate urea feeding pump into tiny liquid drops to an atomizing area of the granulator; the air outlet of the fluidization fan is heated to 80 ℃ by a fluidization air heater, and then the air outlet of the fluidization fan is sent to a granulator and a first cooler to maintain ammonium sulfate urea particles in the granulator and the first cooler in a fluidization state, heat and moisture emitted by the ammonium sulfate urea particles and dust generated in the granulation process are taken away, the residual moisture in the product is not more than 0.5%wt, the ammonium sulfate content is 20%wt, and the urea content is 80%wt; the ammonium sulfate urea particles generated in the granulator are sent to a first cooler, the temperature of the ammonium sulfate urea particles is cooled to 65 ℃, the ammonium sulfate urea particles are easily bonded to the surface of equipment when the cooling temperature is too high, the energy consumption is increased when the cooling temperature is too low, and meanwhile, the equipment is high, so that the arrangement is not facilitated; the method comprises the steps that ammonium sulfate urea particles are divided into standard particles and nonstandard particles in a vibrating screen, specifically, the particle size of the nonstandard particles is smaller, the nonstandard particles are lifted by a circulating bucket elevator and sent back to a granulator to serve as seed crystal materials, the nonstandard particles are slowly accumulated and adhered on seed crystals to be increased and solidified individually to form final standard particles, and then the final standard particles are sent to a final product cooler by a product bucket elevator to be cooled to 45 ℃ to obtain an ammonium sulfate urea product;
the hot gas in the granulator is fully contacted with the ammonium sulfate urea particles, and the moisture of the ammonium sulfate urea particles is evaporated and diffused into the gas to realize the drying of the ammonium sulfate urea particles;
furthermore, the recovery gas cooler is vertical, the bottom is provided with a storage volume, liquid after the recovery tail gas is condensed is stored, a liquid separating tank is not required to be arranged, and a cooling system is optimized; the circulating pump provides power for the tail gas waste heat recovery closed circulating system, and the recovered gas cooler and the recovered gas heater are connected into the closed circulating system;
further, the recovery gas condensing tower is provided with a recovery gas condensing tower liquid level gauge, when the liquid level is lower than a set value, the process water control valve is opened to supplement process water to enable the liquid level of the recovery gas condensing tower to be at a reasonable position, and when the liquid level is higher than the set value, the recovery liquid control valve is opened to drain the recovery liquid to the recovery tank, so that the liquid level of the recovery gas condensing tower is enabled to be at a reasonable position; in the recovery gas condensing tower, the recovery tail gas is cooled by spraying process water, and the water evaporated from the ammonium sulfate urea particles in the granulator is condensed in the recovery gas condensing tower, and meanwhile dust carried by the recovery tail gas is washed away; adding sulfuric acid into a recovery gas condensing tower to absorb ammonia in the tail gas, and recovering the ammonia in the tail gas to the maximum extent; the temperature of the recovered tail gas in the recovered gas condensing tower is controlled by a circulating cooler, and the temperature of the recovered tail gas is as low as possible, generally not exceeding 35 ℃, so that the granulator can absorb the moisture of the ammonium sulfate urea particles; the recovered tail gas condensed by the recovered gas condensing tower carries trace dust and liquid drops, and the condensed recovered gas enters the recovered gas dust removing tower for washing so as to wash the dust in the recovered gas as much as possible, thereby maximally inhibiting the scaling problem in the closed circulation system;
further, the 35 wt% ammonium sulfate urea solution in the recovery tank is pumped into an evaporation heater through a circulating solution pump to be heated and then enters an evaporation separator, the ammonium sulfate urea solution obtained by the evaporation separator enters an ammonium sulfate urea mixing tank, and the condensate obtained by the vapor phase separated by the evaporation separator after passing through an evaporation condenser is recovered to a recovered gas condensing tower to be used as make-up water; to ensure that the ammonium sulphate is totally dissolved and to avoid deposits in the plant, 96% wt urea solution is mixed with 35% wt ammonium sulphate urea solution.
Further, an atomizing air flow meter is arranged at the outlet of the atomizing air blower, and when the flow rate of the atomizing air flow meter of the outlet pipeline of the atomizing air blower is lower than a set value, the air supplementing control valve is used for supplementing lost air; the fluidization air flow meter is arranged at the outlet of the fluidization fan, and when the flow rate of the fluidization air flow meter of the outlet pipeline of the fluidization fan is lower than a set value, the air supplementing control valve is used for supplementing lost air; and then the recovered tail gas is sent into an atomizing air heater through an atomizing blower, and is sent into a fluidization air heater through a fluidization blower, the heated gas has the capability of fluidizing and drying ammonium sulfate urea particles again, and the gas enters a new round of closed circulation ammonium sulfate urea fluidized bed granulation work.
Furthermore, the recycling tail gas treatment system consisting of the recycling gas condensing tower, the recycling gas dedusting tower, the circulating cooler, the recycling gas condensing tower circulating pump and the recycling gas dedusting tower circulating pump is used for efficiently treating moisture, dust and ammonia in the recycling tail gas, the tail gas is not required to be directly discharged to be amplified, the gas recycling is realized, on one hand, the cost is saved due to the recycling of the ammonia, the economic benefit is extremely high, on the other hand, the ammonia emission is reduced, and meanwhile, the dust-free and ammonia-containing tail gas emission is realized, so that the environment benefit is extremely high;
further, the recycling gas cooler can cool recycling tail gas on one hand, so that circulating water of the circulating cooler is saved, on the other hand, heat energy of the recycling tail gas is recycled, the heat energy is transmitted to the recycling tail gas after the recycling gas dedusting tower through the recycling gas heater, and steam consumption of the atomizing air heater and the fluidizing air heater is saved; the tail gas waste heat recovery closed circulation system realizes waste heat recovery of recovered tail gas, reduces consumption of steam and circulating water, and has certain economic benefit and environmental benefit;
furthermore, the tail gas closed circulation system and the ammonium sulfate urea solution recovery system ensure that no gas, liquid, solid and dust are discharged outside the device, all overflows are collected and recovered in the device, no waste water or industrial waste residue is generated, and certain economic benefit and environmental benefit are achieved.
Compared with the prior art, the closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery has the following advantages:
the closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery is suitable for granulation of an ammonium sulfate urea fluidized bed and provides technical support for an ammonium sulfate urea fluidized bed granulation process; the closed circulation system recovers ammonia in the tail gas, so that the cost is saved, and great economic benefits are achieved; the closed circulation system recovers ammonia to reduce ammonia emission, and simultaneously realizes dust-free and ammonia-containing tail gas emission, thereby having great environmental benefit; the tail gas waste heat recovery closed circulation system realizes tail gas waste heat recovery, reduces the consumption of steam and circulating water, and has certain economic benefit and environmental benefit.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute an undue limitation on the invention. In the drawings:
fig. 1 is a schematic diagram of a simple process flow of a closed-cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery.
Reference numerals illustrate:
a 1-ammonium sulfate urea mixing tank; 2-a stirrer; 3-ammonium sulfate urea heater; 4-ammonium sulfate urea feed pump; 11-a granulator; 12-a first cooler; 13-a fluidization fan; 14-atomizing blower; 15-an atomizing air heater; 16-a fluidization air heater; 17-an air supply control valve; 18-an atomized air flow meter; 19-an atomizing air control valve; 20-a fluidization air control valve; 21-a fluidising air flow meter; 22-a vibrating screen; 23-circulating bucket elevator; 24-a product bucket elevator; 25-final cooler; 26-cyclone separator; 31-a recycle gas cooler; 32-a recycle gas heater; 33-a circulation pump; 41-a recovered gas condensing column; 42-a recovered gas dust removal tower; 43-a circulation cooler; 44-a recycle gas condensing tower circulating pump; 45-a recycle gas dust removal tower circulating pump; 46-a process water control valve; 47-recovery solution control valve; 48-a recycle gas condensing tower liquid level gauge; 51-a recovery tank; 52-circulating solution pump; 53-an evaporation heater; 54-an evaporation separator; 55-evaporative condenser.
Detailed Description
It should be noted that, without conflict, embodiments of the invention and features of the embodiments may be combined with each other.
In the description of the invention, it should be understood that the terms "center," "longitudinal," "transverse," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships that are based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the invention and simplify the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be configured and operate in a particular orientation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", etc. may explicitly or implicitly include one or more such feature. In the description of the invention, unless otherwise indicated, the meaning of "a plurality" is two or more.
In the description of the invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the creation of the present invention can be understood by those of ordinary skill in the art in a specific case.
The invention will be described in detail below with reference to the drawings in connection with embodiments.
As shown in fig. 1, the closed-cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery comprises a feeding system, a granulation system, a tail gas waste heat recovery system, a tail gas closed-cycle system and an ammonium sulfate urea solution recovery system;
the feeding system comprises an ammonium sulfate urea mixing tank 1, a stirrer 2, an ammonium sulfate urea heater 3 and an ammonium sulfate urea feeding pump 4;
the granulating system comprises a granulator 11, a first cooler 12, a fluidization fan 13, an atomizing blower 14, an atomizing air heater 15, a fluidization air heater 16, a vibrating screen 22, a circulating bucket elevator 23, a product bucket elevator 24, a final cooler 25 and a cyclone separator 26;
the tail gas waste heat recovery system comprises a recovered gas cooler 31, a recovered gas heater 32 and a circulating pump 33;
the tail gas closed circulation system comprises a recovered gas condensing tower 41, a recovered gas dedusting tower 42, a circulating cooler 43, a recovered gas condensing tower circulating pump 44 and a recovered gas dedusting tower circulating pump 45;
the ammonium sulfate urea solution recovery system comprises a recovery tank 51, a circulating solution pump 52, an evaporation heater 53, an evaporation separator 54 and an evaporation condenser 55;
preferably, in the feeding system, an inlet of an ammonium sulfate urea mixing tank 1 is provided with 27% wt of aluminum sulfate solution feeding, 96% wt of urea solution feeding, an evaporation separator 54 and a stirrer 2, and an outlet of an ammonium sulfate urea feeding pump 4 is connected with a granulator 11 of the granulating system; the aluminum sulfate solution and the urea solution are added into an ammonium sulfate urea mixing tank (1) through a feed inlet, and ammonium sulfate powder enters the sodium sulfate urea mixing tank (1) through a stirrer (2); the ammonium sulfate urea heater (3) is connected to the stirrer (2) and is used for heating the ammonium sulfate urea solution in the stirrer (2);
preferably, in the granulating system, a feed inlet of a granulator 11 is connected with an ammonium sulfate urea feed pump 4, an air inlet is connected with an atomization air heater 15 and a fluidization air heater 16, a discharge outlet of the granulator 11 is connected with a first cooler 12, an air outlet of the granulator 11 is connected with a cyclone 26, a discharge outlet of the cyclone 26 returns to the first cooler 12, and an air outlet of the cyclone 26 is connected with a recovery gas cooler 31 of the tail gas waste heat recovery system; an air inlet of the atomizing blower 14 is connected with a recovery air heater 32 of the tail gas waste heat recovery system, an air outlet of the atomizing blower 14 is connected with an atomizing air heater 15, and an air outlet of the atomizing air heater 15 is connected with the granulator 11; the air inlet of the fluidization fan 13 is connected with a recovery air heater 32 of the tail gas waste heat recovery system, the air outlet of the fluidization fan 13 is connected with a fluidization air heater 16 and a first cooler 12, and the air outlet of the fluidization air heater 16 is connected with the granulator 11; the discharge port of the first cooler 12 is connected with a vibrating screen 22, the discharge port of the vibrating screen 22 is connected with a circulating bucket elevator 23 and a product bucket elevator 24, the discharge of the circulating bucket elevator 23 returns to the granulator 11, the discharge port of the product bucket elevator 24 is connected with a final cooler 25, and the outlet of the final cooler 25 is the ammonium sulfate urea product;
preferably, in the tail gas waste heat recovery system, an air inlet of a recovered gas cooler 31 is connected with a cyclone separator 26, an air outlet of the recovered gas cooler is connected with a recovered gas condensing tower 41, an air inlet of a recovered gas heater 32 is connected with a recovered gas dust removing tower 42, an air outlet of the recovered gas heater is connected with a fluidization fan 13 and an atomization blower 14, and a circulating pump 33 connects the recovered gas cooler 31 and the recovered gas heater 32 into a closed circulating system;
preferably, in the tail gas closed circulation system, the bottom of the recovery gas condensation tower 41 is connected with a recovery gas condensation tower circulating pump 44, the recovery gas condensation tower circulating pump 44 is connected with a circulating cooler 43, the recovery gas dust removal tower 42 is connected with the recovery gas condensation tower 41, the bottom of the recovery gas dust removal tower 42 is connected with a recovery gas dust removal tower circulating pump 45, and an air outlet of the recovery gas dust removal tower 42 is connected with the recovery gas heater 32 of the tail gas waste heat recovery system;
preferably, in the ammonium sulfate urea solution recovery system, an inlet of a recovery tank 51 is connected with a recovery gas condensing tower 41, an outlet of the recovery tank 51 is connected with a circulating solution pump 52, an outlet of the circulating solution pump 52 is connected with an evaporation heater 53, a discharge port of the evaporation heater 53 is connected with an evaporation separator 54, a liquid outlet of the evaporation separator 54 is connected with an ammonium sulfate urea mixing tank 1, an air outlet of the evaporation separator 54 is connected with an evaporation condenser 55, and a liquid outlet of the evaporation condenser 55 returns to the recovery gas condensing tower 41;
preferably, 27% wt of aluminum sulfate solution is used as a granulating additive, so as to inhibit dust generation in the granulating process, inhibit scarring of the granulator and prolong the cleaning period of the granulator; the ammonium sulphate powder is thoroughly mixed with the heated molten urea in the mixer 2 to ensure complete dissolution of the ammonium sulphate powder in the urea solution.
Specifically, the air outlet of the atomizing blower 14 is heated to 140 ℃ by the atomizing air heater 15, and then the auxiliary liquid nozzle atomizes the ammonium sulfate urea solution conveyed by the ammonium sulfate urea feed pump 4 into tiny liquid drops to the atomizing area of the granulator; the air outlet of the fluidization fan 13 is heated to 80 ℃ by the fluidization air heater 16, and then is sent to the granulator 11 and the first cooler 12 to maintain the ammonium sulfate urea particles in the granulator 11 and the first cooler 12 in a fluidization state, and take away the heat and moisture emitted by the ammonium sulfate urea particles and the dust generated in the granulation process, wherein the residual moisture in the product is not more than 0.5%wt, the ammonium sulfate content is 20%wt, and the urea content is 80%wt;
the ammonium sulfate urea granules produced in the granulator 11 are sent to a first cooler 12, where the ammonium sulfate urea granules are cooled to 65 ℃, and the ammonium sulfate urea granules are easily bonded to the surface of equipment when the cooling temperature is too high, so that the energy consumption is increased, and meanwhile, the equipment becomes high, which is unfavorable for arrangement; the ammonium sulfate urea granules are screened into two specifications of standard granules and nonstandard granules in a vibrating screen 22, the nonstandard granules are lifted by a circulating bucket elevator 23 and sent back to a granulator 11 to be used as seed materials, the nonstandard granules are slowly accumulated and adhered and increased on the seed and are solidified individually to form standard granules, and then the standard granules are sent to a final product cooler 25 by a product bucket elevator 24 to be cooled to 45 ℃ to obtain an ammonium sulfate urea product; the hot gas in the granulator 11 is fully contacted with the ammonium sulfate urea particles, and the moisture of the ammonium sulfate urea particles is evaporated and diffused into the gas to realize the drying of the ammonium sulfate urea particles;
preferably, the recycle gas cooler 31 is vertical, and the bottom is provided with a storage volume for storing the liquid after the condensation of the recycle tail gas, so that a liquid separating tank is not required to be arranged, and a cooling system is optimized; the circulating pump 33 provides power for a tail gas waste heat recovery closed circulating system, and connects the recovered gas cooler 31 and the recovered gas heater 32 into the closed circulating system;
preferably, the recovery gas condensing tower 41 is provided with a recovery gas condensing tower liquid level gauge 48, when the liquid level is lower than a set value, the process water control valve 46 opens the supplementary process water to enable the liquid level of the recovery gas condensing tower 41 to be at a reasonable position, and when the liquid level is higher than the set value, the recovery liquid control valve 47 opens to drain the recovery liquid to the recovery tank 51 to enable the liquid level of the recovery gas condensing tower 41 to be at a reasonable position; in the recovered gas condensing tower 41, the recovered tail gas is cooled by spraying process water, and the water evaporated from the urea ammonium sulfate particles in the granulator 11 is condensed in the recovered gas condensing tower 41, and at the same time, dust carried in the recovered tail gas is washed away; sulfuric acid is added into the recovery gas condensing tower 41 to absorb ammonia in the tail gas, so that the ammonia in the tail gas is recovered to the maximum extent; the temperature of the recovered tail gas in the recovered gas condensing tower 41 is controlled by the recycle cooler 43, and the temperature of the recovered tail gas should be as low as possible, typically not exceeding 35 ℃, so that the granulator 11 can absorb the moisture of the urea ammonium sulphate particles; the recovered tail gas condensed by the recovered gas condensing tower 41 carries trace dust and droplets, and the condensed recovered gas enters the recovered gas dust removing tower 42 for washing so as to wash the dust in the recovered gas as much as possible, thereby maximally inhibiting the scaling problem in the closed circulation system.
Preferably, 35% wt of the ammonium sulfate urea solution in the recovery tank 51 is sent to the evaporation heater 53 through the circulating solution pump 52 to be heated and then enters the evaporation separator 54, the ammonium sulfate urea solution obtained by the evaporation separator 54 enters the ammonium sulfate urea mixing tank 1, and the condensate obtained by the evaporation condenser 55 of the gas phase separated by the evaporation separator 54 is recovered to the recovered gas condensing tower 41 to be used as make-up water; to ensure that the ammonium sulphate is totally dissolved and to avoid deposits in the plant, 96% wt urea solution is mixed with 35% wt ammonium sulphate urea solution.
Preferably, an atomized air flow meter 18 is arranged at the outlet of the atomized air blower 14, and when the flow rate of the atomized air flow meter 18 at the outlet pipeline of the atomized air blower 14 is lower than a set value, the air supplementing control valve 17 is opened to supplement the lost air; the outlet of the fluidization fan 13 is provided with a fluidization air flow meter 21, and when the flow rate of the fluidization air flow meter 21 of the outlet pipeline of the fluidization fan 13 is lower than a set value, the air supplementing control valve 17 is opened to supplement the lost air; and then the recovered tail gas is sent into an atomizing air heater 15 through an atomizing blower 14, is sent into a fluidization air heater 16 through a fluidization blower 13, and the heated gas has the capability of fluidizing and drying ammonium sulfate urea particles again, and enters a new round of closed circulation ammonium sulfate urea fluidized bed granulation work.
Preferably, the recycling tail gas treatment system consisting of the recycling gas condensing tower 41, the recycling gas dedusting tower 42, the circulating cooler 43, the recycling gas condensing tower circulating pump 44 and the recycling gas dedusting tower circulating pump 45 is used for efficiently treating water, dust and ammonia in the recycling tail gas, directly exhausting the tail gas to the atmosphere is not needed, the gas recycling is realized, on one hand, the cost is saved due to the recycling of the ammonia, the economic benefit is extremely high, on the other hand, the ammonia emission is reduced, and meanwhile, the dust-free and ammonia-containing tail gas emission is also realized, so that the recycling tail gas treatment system has extremely high environmental benefit.
Further, the recycle gas cooler 31 can cool the recycle tail gas on the one hand, so that the recycle water of the recycle cooler 43 is saved, and on the other hand, the heat energy of the recycle tail gas is recycled, and the heat energy is transferred to the recycle tail gas after passing through the recycle gas heater 32 to the recycle gas dust removal tower 42, so that the steam consumption of the atomizing air heater 15 and the fluidization air heater 16 is saved; the tail gas waste heat recovery closed circulation system realizes waste heat recovery of recovered tail gas, reduces consumption of steam and circulating water, and has certain economic benefit and environmental benefit.
Furthermore, the tail gas closed circulation system and the ammonium sulfate urea solution recovery system ensure that no gas, liquid, solid and dust are discharged outside the device, all overflows are collected and recovered in the device, and no waste water or industrial waste residue is generated, so that the device has certain economic benefit and environmental benefit.
According to the method, a mixed solution of 96 wt% of urea solution and ammonium sulfate can be produced into an ammonium sulfate urea product (the water content is about 0.5 wt%) by utilizing a closed-cycle ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery.
Examples:
the application example of the device for producing the ammonium sulfate urea with the annual production of 60 ten thousand tons/year is further described.
The flow rate of the ammonium sulfate urea solution is 77t/h, the temperature is 140 ℃, the water content is 3%wt, and the ammonium sulfate urea solution enters a granulator 11 through a ammonium sulfate urea feed pump 4; the flow rate of an atomizing blower 14 is 35000m3/h, the temperature is 35 ℃, the temperature is heated to 140 ℃ through an atomizing air heater 15, then an auxiliary liquid nozzle atomizes an ammonium sulfate urea solution into tiny liquid drops to an atomizing area of a granulator, the flow rate of a fluidization blower 13 is 300000m3/h, the temperature is 35 ℃, the temperature is heated to 80 ℃ through a fluidization air heater 16, the ammonium sulfate urea particles in the granulator 11 and the first cooler 12 are maintained in a fluidized state, heat and moisture emitted by the ammonium sulfate urea particles and dust generated in the granulating process are taken away, the ammonium sulfate urea flow rate obtained in the granulator is 107t/h, the temperature is 105 ℃, the water content is 0.5% wt, after the ammonium sulfate urea flow rate is 107t/h, the temperature is 65 ℃, the water content is 0.5% wt, then the ammonium sulfate urea passes through a vibrating screen, the ammonium sulfate urea with about 30% is passed through a circulating bucket elevator 23 to the granulator 11, the ammonium sulfate urea with about 70% is passed through a product bucket elevator 24 to a final cooler 25, the cooling of the ammonium sulfate urea is realized, the ammonium sulfate urea flow rate obtained in the granulator is 75t/h, the water content is 45% wt, and the water content of the ammonium sulfate urea obtained is 45% wt; tail gas (temperature 80 ℃) of the granulator 11 and the first cooler 12 enters the cyclone separator 26, powder after cyclone separation enters the first cooler 12 from the lower part of the cyclone separator 26, the temperature of the recovered tail gas after cyclone separation enters the recovered gas cooler 31 to be cooled to 65 ℃, at the moment, the temperature of cooling water is increased from 52 ℃ to 60 ℃, and 160t/h of cooling water of the circulating cooler 43 is saved; then the recovered tail gas enters a recovered gas condensing tower 41, the recovered tail gas is cooled by spraying process water, the water evaporated by the ammonium sulfate urea particles in the granulator 11 is condensed in the recovered gas condensing tower 41, meanwhile, dust carried by the recovered tail gas is washed away, the heat of the recovered tail gas is absorbed, the heat of the recovered tail gas is taken away by a circulating cooler 43, the recovered tail gas is cooled to 35 ℃, and the flow rate of a circulating pump 24 is 800m < 3 >/h; then the condensed recovered gas enters a recovered gas dust removal tower 42 for washing so as to wash dust in the recovered gas as much as possible, the scaling problem in a closed circulation system is inhibited to the maximum extent, and the flow of a circulation pump 45 is 300m3/h; the temperature of the recovered tail gas after dust removal, ammonia removal and cooling is increased to 50 ℃ after passing through the recovered gas heater 32, and at the moment, the temperature of circulating water is reduced from 60 ℃ to 52 ℃, so that the steam quantity of the gas heater is saved by 3t/h; and then the recovered tail gas is sent into a gas heater atomizing air heater 15 through an atomizing blower 14, the recovered tail gas is sent into a gas heater 16 through a fluidization blower 13, the heated gas has the capability of fluidizing and drying ammonium sulfate urea particles again, and the gas enters a new round of closed circulation ammonium sulfate urea fluidized bed granulation work. The tail gas emission of dust-free and ammonia-containing is realized in the operation process, the circulated water is saved by 1280000 t/year, and the steam is saved by 24000 t/year.
The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The closed circulation ammonium sulfate urea fluidized bed granulation system with the tail gas waste heat recovery comprises a feeding system, a granulation system, a tail gas waste heat recovery system, a tail gas closed circulation system and an ammonium sulfate urea solution recovery system;
the feeding system is used for preparing production raw materials;
the granulating system is used for manufacturing ammonium sulfate urea;
the tail gas waste heat recovery system is used for collecting tail gas waste heat generated in production;
the tail gas closed circulation system is used for treating water, dust and ammonia in the recovered tail gas;
the ammonium sulfate urea solution recovery system is used for recovering the ammonium sulfate urea solution.
2. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 1, wherein: the feeding system comprises an ammonium sulfate urea mixing tank (1), a stirrer (2), an ammonium sulfate urea heater (3) and an ammonium sulfate urea feeding pump (4);
the production raw materials comprise aluminum sulfate solution, urea solution and ammonium sulfate powder; the aluminum sulfate solution and the urea solution are added into an ammonium sulfate urea mixing tank (1) through a feed inlet, and ammonium sulfate powder enters the sodium sulfate urea mixing tank (1) through a stirrer (2); the ammonium sulfate urea heater (3) is connected to the stirrer (2) and is used for heating the ammonium sulfate urea solution in the stirrer (2), and the ammonium sulfate urea mixing tank (1) is connected with a granulator (11) of the granulating system through an ammonium sulfate urea feed pump (4).
3. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 1, wherein: the granulating system comprises a granulator (11), a first cooler (12), a fluidization fan (13), an atomizing blower (14), an atomizing air heater (15), a fluidization air heater (16), a vibrating screen (22), a circulating bucket elevator (23), a product bucket elevator (24), a final cooler (25) and a cyclone separator (26);
the feed inlet of the granulator (11) is connected with an ammonium sulfate urea feed pump (4), the air inlet of the granulator (11) is connected with an atomization air heater (15) and a fluidization air heater (16), the discharge outlet of the granulator (11) is connected with a first cooler (12), the air outlet of the granulator (11) is connected with a cyclone separator (26), the discharge outlet of the cyclone separator (26) returns to the first cooler (12), and the air outlet of the cyclone separator (26) is connected with a recovery air cooler (31) of a tail gas waste heat recovery system; an air inlet of the atomizing blower (14) is connected with a recovery air heater (32) of the tail gas waste heat recovery system, an air outlet of the atomizing blower (14) is connected with an air inlet of the atomizing air heater (15), and an air outlet of the atomizing air heater (15) is connected with the granulator (11); an air inlet of the fluidization fan (13) is connected with a recovery air heater (32) of the tail gas waste heat recovery system, an air outlet of the fluidization fan (13) is connected with a fluidization air heater (16) and a first cooler (12), and an air outlet of the fluidization air heater (16) is connected with the granulator (11); the discharge port of the first cooler (12) is connected with a vibrating screen (22), the discharge port of the vibrating screen (22) is connected with a circulating bucket elevator (23) and a product bucket elevator (24), the discharge of the circulating bucket elevator (23) returns to the granulator (11), the discharge port of the product bucket elevator (24) is connected with a final cooler (25), and the outlet of the final cooler (25) is the ammonium sulfate urea product.
4. A closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery as set forth in claim 3, wherein: the tail gas waste heat recovery system comprises a recovered gas cooler (31), a recovered gas heater (32) and a circulating pump (33);
the air inlet of the recovered gas cooler (31) is connected with the cyclone separator (26), the air outlet is connected with the recovered gas condensing tower (41) of the tail gas closed circulation system, the air inlet of the recovered gas heater (32) is connected with the recovered gas dust removing tower (42) of the tail gas closed circulation system, and the air outlet of the recovered gas heater (32) is connected with the fluidization fan (13) and the atomizing blower (14); the recycle pump (33) connects the recycle gas cooler (31) and the recycle gas heater (32) into a closed circulation system.
5. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 4, wherein: the tail gas closed circulation system comprises a recovered gas condensing tower (41), a recovered gas dust removing tower (42), a circulating cooler (43), a recovered gas condensing tower circulating pump (44) and a recovered gas dust removing tower circulating pump (45);
the bottom of the recovery gas condensing tower (41) is connected with a recovery gas condensing tower circulating pump (44), the recovery gas condensing tower circulating pump (44) is connected with a circulating cooler (43), the recovery gas dedusting tower (42) is connected with the recovery gas condensing tower (41), the bottom of the recovery gas dedusting tower (42) is connected with a recovery gas dedusting tower circulating pump (45), and an air outlet of the recovery gas dedusting tower (42) is connected with a recovery gas heater (32) of the tail gas waste heat recovery system.
6. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 5, wherein: the ammonium sulfate urea solution recovery system comprises a recovery tank (51), a circulating solution pump (52), an evaporation heater (53), an evaporation separator (54) and an evaporation condenser (55);
the inlet of the recovery tank (51) is connected with the recovery gas condensing tower (41), the outlet of the recovery tank (51) is connected with the circulating solution pump (52), the outlet of the circulating solution pump (52) is connected with the evaporation heater (53), the discharge port of the evaporation heater (53) is connected with the evaporation separator (54), the liquid outlet of the evaporation separator (54) is connected with the ammonium sulfate urea mixing tank (1), the gas outlet of the evaporation separator (54) is connected with the evaporation condenser (55), and the liquid outlet of the evaporation condenser (55) returns to the recovery gas condensing tower (41).
7. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 2, wherein: the concentration of the aluminum sulfate solution is 27%wt; the urea solution had a concentration of 96% wt.
8. A closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery as set forth in claim 3, wherein: the air outlet of the atomizing blower (14) is heated to 140 ℃ by an atomizing air heater (15); the air outlet of the fluidization fan (13) is heated to 80 ℃ by a fluidization air heater (16);
the ammonium sulfate urea granules are screened in a vibrating screen (22) into standard granules and nonstandard granules; non-standard particles are lifted by a circulating bucket elevator (23) and returned to the granulator (11) to be used as seed materials; the ammonium sulfate urea granules are slowly accumulated and adhered on the seed crystal to be increased and solidified to form standard granules, and the standard granules are sent to a final product cooler (25) by a product bucket elevator (24) to be cooled to 45 ℃ to obtain the ammonium sulfate urea product.
9. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 5, wherein: the recovery gas cooler (31) is vertical, and the bottom of the recovery gas cooler is provided with a storage volume for storing liquid after the recovery tail gas is condensed;
the recovery gas condensing tower (41) is provided with a recovery gas condensing tower liquid level meter (48) for monitoring the liquid level condition.
10. The closed cycle urea ammonium sulfate fluidized bed granulation system with tail gas waste heat recovery of claim 5, wherein: an atomization air flow meter (18) is arranged at the outlet of the atomization blower (14) and is used for monitoring the gas flow of an outlet pipeline of the atomization blower (14).
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| CN202310471831.6A CN116422226A (en) | 2023-04-27 | 2023-04-27 | Closed circulation ammonium sulfate urea fluidized bed granulation system with tail gas waste heat recovery |
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