CN118988206A - Urea synthesis device - Google Patents
Urea synthesis device Download PDFInfo
- Publication number
- CN118988206A CN118988206A CN202411467920.4A CN202411467920A CN118988206A CN 118988206 A CN118988206 A CN 118988206A CN 202411467920 A CN202411467920 A CN 202411467920A CN 118988206 A CN118988206 A CN 118988206A
- Authority
- CN
- China
- Prior art keywords
- pressure
- tower
- urea synthesis
- urine
- pipeline
- 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.)
- Granted
Links
- 239000004202 carbamide Substances 0.000 title claims abstract description 154
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 title claims abstract description 153
- 238000003786 synthesis reaction Methods 0.000 title claims abstract description 150
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 142
- 238000005406 washing Methods 0.000 claims abstract description 81
- 210000002700 urine Anatomy 0.000 claims abstract description 78
- 239000002184 metal Substances 0.000 claims abstract description 51
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 49
- BAVYZALUXZFZLV-UHFFFAOYSA-O Methylammonium ion Chemical compound [NH3+]C BAVYZALUXZFZLV-UHFFFAOYSA-O 0.000 claims abstract description 47
- 239000007788 liquid Substances 0.000 claims abstract description 33
- 238000000354 decomposition reaction Methods 0.000 claims abstract description 26
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 23
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 claims description 84
- 238000010521 absorption reaction Methods 0.000 claims description 32
- BVCZEBOGSOYJJT-UHFFFAOYSA-N ammonium carbamate Chemical compound [NH4+].NC([O-])=O BVCZEBOGSOYJJT-UHFFFAOYSA-N 0.000 claims description 23
- KXDHJXZQYSOELW-UHFFFAOYSA-N carbonic acid monoamide Natural products NC(O)=O KXDHJXZQYSOELW-UHFFFAOYSA-N 0.000 claims description 23
- 230000001105 regulatory effect Effects 0.000 claims description 15
- 238000001704 evaporation Methods 0.000 claims description 13
- 238000009833 condensation Methods 0.000 claims description 11
- 230000005494 condensation Effects 0.000 claims description 11
- 230000008020 evaporation Effects 0.000 claims description 11
- 238000007599 discharging Methods 0.000 claims description 3
- 239000013589 supplement Substances 0.000 claims description 2
- 238000006243 chemical reaction Methods 0.000 abstract description 37
- 238000000034 method Methods 0.000 abstract description 16
- 230000008569 process Effects 0.000 abstract description 16
- 239000000463 material Substances 0.000 abstract description 7
- 239000006227 byproduct Substances 0.000 abstract description 5
- 230000000694 effects Effects 0.000 abstract description 5
- 229910000069 nitrogen hydride Inorganic materials 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 22
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 19
- 239000012295 chemical reaction liquid Substances 0.000 description 17
- 239000000243 solution Substances 0.000 description 15
- 229910002092 carbon dioxide Inorganic materials 0.000 description 11
- 238000004519 manufacturing process Methods 0.000 description 9
- 239000001569 carbon dioxide Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 8
- 239000012071 phase Substances 0.000 description 8
- 238000011084 recovery Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 238000006297 dehydration reaction Methods 0.000 description 6
- 238000005265 energy consumption Methods 0.000 description 6
- 239000011261 inert gas Substances 0.000 description 5
- 239000007791 liquid phase Substances 0.000 description 5
- 230000002035 prolonged effect Effects 0.000 description 5
- 238000002156 mixing Methods 0.000 description 4
- 230000002194 synthesizing effect Effects 0.000 description 4
- 230000018044 dehydration Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000004064 recycling Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 239000007991 ACES buffer Substances 0.000 description 1
- 239000006173 Good's buffer Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000000872 buffer Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000011552 falling film Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- YWWMFIAQYSERJF-UHFFFAOYSA-N methanamine;urea Chemical compound NC.NC(N)=O YWWMFIAQYSERJF-UHFFFAOYSA-N 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 238000004094 preconcentration Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 150000003672 ureas Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/009—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping in combination with chemical reactions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
- B01D3/148—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step in combination with at least one evaporator
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/34—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping with one or more auxiliary substances
- B01D3/38—Steam distillation
-
- 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
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
-
- 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
- B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
- B01J3/04—Pressure vessels, e.g. autoclaves
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
- C07C273/14—Separation; Purification; Stabilisation; Use of additives
- C07C273/16—Separation; Purification
-
- 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
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00002—Chemical plants
- B01J2219/00004—Scale aspects
- B01J2219/00006—Large-scale industrial plants
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
本申请涉及一种尿素合成装置，包括高压合成系统、中压分解系统、低压分解系统以及尿液蒸发器；所述高压合成系统包括尿素合成塔、汽提塔、氨预热器、甲铵洗涤冷凝器以及高压喷射器；所述尿素合成塔为立式塔，包括由金属壳体、内部塔盘以及金属管所组成的高压反应器，所述甲铵洗涤冷凝器包括上下分布的洗涤段及冷凝段，所述冷凝段的壳体上连接有立式汽包。本发明中尿素合成塔能够提高反应物料停留时间，提高反应收率。甲铵洗涤冷凝器能够将生成甲铵液过程中未反应的NH3和CO2进行吸收并继续反应生成甲铵，提高蒸汽副产量，达到节能降耗，提高转化率的技术效果，每吨尿素蒸汽用量减少20%。
The present application relates to a urea synthesis device, including a high-pressure synthesis system, a medium-pressure decomposition system, a low-pressure decomposition system and a urine evaporator; the high-pressure synthesis system includes a urea synthesis tower, a stripping tower, an ammonia preheater, a methylammonium washing condenser and a high-pressure ejector; the urea synthesis tower is a vertical tower, including a high-pressure reactor composed of a metal shell, an internal tray and a metal tube, the methylammonium washing condenser includes a washing section and a condensing section distributed up and down, and a vertical steam drum is connected to the shell of the condensing section. In the present invention, the urea synthesis tower can increase the residence time of the reaction materials and improve the reaction yield. The methylammonium washing condenser can absorb the unreacted NH3 and CO2 in the process of generating methylammonium liquid and continue to react to generate methylammonium, increase the steam by-product, achieve energy saving and consumption reduction, and improve the technical effect of conversion rate, and reduce the steam consumption per ton of urea by 20%.
Description
Technical Field
The application relates to the technical field of urea production, in particular to a urea synthesis device.
Background
The urea production technology in the world at present mainly comprises the following steps: CO 2 stripping process from Tomibacon, netherlands, NH 3 stripping process from Lignomo Luo Jidi, japan, ACES process. Either process is carried out by reacting excess ammonia with carbon dioxide at a pressure of 12-40MPa (a) and a temperature of 150-250 c:
the first step is an exothermic reaction to form ammonium carbamate:
2NH3+CO2→H2N-CO-ONH4
The second step is the dehydration of the ammonium carbamate formed to urea by an endothermic equilibrium reaction:
H2N-CO-ONH4=H2N-CO-NH2+H2O
the reaction is carried out at a certain temperature and pressure, urea, ammonium carbamate, water and unreacted ammonia are generated in the high-pressure urea synthesis reaction zone, the ammonium carbamate and the ammonia are removed from the solution, and the solution is returned to the urea synthesis zone for continuous reaction. In addition to the solution, a gas mixture is formed in the urea synthesis reaction, which gas mixture consists of unreacted ammonia and carbon dioxide and inert gas exhaust gases, ammonia being recovered by water absorption.
The decomposition of ammonium carbamate that is not converted to urea in the high pressure urea synthesis reaction zone is typically performed by thermal stripping with carbon dioxide and/or ammonia in a stripper and the decomposition of ammonium carbamate into ammonia and carbon dioxide, the heat required for the decomposition being provided by steam or other heat sources provided by external heat sources. Stripping removes the ammonia and carbon dioxide present and condenses in the high pressure condenser before being returned to the urea synthesis section.
The urea after the stripping treatment is decomposed by being lower than the pressure of the synthesis section, and the ammonium carbamate is returned to the urea synthesis section. The recovery device is usually a single device, can also be a multi-stage recovery device arranged in series, and can be arranged according to the principle of lowest energy consumption.
In the traditional CO 2 stripping process at present, the high-pressure ring operates under the guidance of an optimization theory: the synthesis pressure adopts the lowest equilibrium pressure, the ammonia/carbon ratio adopts the ammonia/carbon ratio (2.95) in the lowest azeotropic composition, the operation pressure is 13.5-14.5MPa (A), the temperature is 180-183 ℃, the condensation temperature is 167 ℃, the stripping temperature is about 190 ℃, and the stripping efficiency is more than 80%. These parameters are mild, so that the main equipment material adopts 316L or 25-22-2CrNiMo, and the requirement of strong corrosion resistance of the material can be met by matching with a sufficient amount of passivation air, and the equipment is convenient to manufacture and maintain. Because the stripping efficiency is higher, the requirement of material recycling can be met only by arranging a low-pressure recycling section, but high-level heat energy is not utilized, so that the steam consumption of the whole urea synthesis device is higher.
The urea synthesizing tower is a key device in the urea production process, and makes ammonia and carbon dioxide carry out urea synthesis reaction under the conditions of high pressure and high temperature. The urea synthesis tower generally adopts an empty tower or is provided with a mixer or a sieve plate, the reaction liquid flows along the axial direction of the synthesis tower, and as the sieve plate or the mixer is provided with holes, the pressure drop during gas phase perforation is larger than that of a liquid phase passing through an annular space of the synthesis tower, so that the liquid phase and the gas phase are mixed above the tower plate, the reaction of generating urea by methyl ammonium dehydration is carried out, and vortex is generated in the mixing flow process, namely back mixing is generated. Due to the presence of back mixing, the reaction rate of the methylamine is reduced during the urea synthesis, which is manifested by a reduced conversion of CO 2. In addition, the urea synthesis tower is generally internally provided with a central tube for guiding out the reaction liquid, so that not only is the space for the reaction of the methyl ammonium occupied, but also the equipment investment is increased.
In the urea production process, a stripping tower decomposes most of CO 2 and NH 3 generated by methyl ammonium in urea solution, and the CO 2 and the NH 3 are condensed in a high-pressure condenser to generate methyl ammonium solution; the inert gas discharged from the urea synthesis tower is used for recycling NH 3 in the inert gas through a high-pressure scrubber. This process requires two high pressure devices, a high pressure scrubber and a high pressure condenser, which are independently located not only to increase floor space but also to increase equipment manufacturing costs.
The invention is provided for solving the problems of high energy consumption, large equipment investment and low reaction efficiency in urea production.
Disclosure of Invention
The application aims to provide a urea synthesis device, which can optimize a high-pressure reaction part, improve the reaction yield, achieve the technical effect of energy conservation, and simultaneously realize graded recovery and graded energy utilization so as to achieve the aim of reducing energy consumption.
In order to achieve the above object, the present invention provides a urea synthesis device, comprising a high-pressure synthesis system, a medium-pressure decomposition system, a low-pressure decomposition system and a urine evaporator;
The high-pressure synthesis system comprises a urea synthesis tower, a stripping tower, an ammonia preheater, a methyl ammonium washing condenser and a high-pressure ejector which are connected through a pipeline;
The methylamine washing condenser comprises a washing section and a condensing section which are distributed up and down, and a vertical steam drum is connected to a shell of the condensing section;
The medium-pressure decomposition system comprises a medium-pressure rectifying tower, a medium-pressure separator and a connecting pipeline, and the low-pressure decomposition system comprises a low-pressure rectifying tower, a low-pressure separator and a connecting pipeline;
The urea synthesis tower is a vertical tower and comprises a high-pressure reactor composed of a metal shell, an internal tray and metal pipes, wherein the internal tray comprises a plurality of baffle plates which are alternately arranged along the axial direction of the urea synthesis tower at intervals, each baffle plate is a non-porous baffle plate, the urea synthesis tower is filled with urine, and the urine flows back from bottom to top through the baffle plates in the urea synthesis tower;
The metal pipe is connected to the top of the urea synthesis tower, the metal pipe comprises a bent pipe section, urine in the urea synthesis tower flows back to the top of the tower and is guided out through the metal pipe and flows downwards, the metal pipe comprises a metal pipe horizontal section and a metal pipe vertical section, and the metal pipe vertical section is arranged in parallel with the urea synthesis tower in the axial direction.
In an alternative embodiment, the metal pipe is connected with the top of the stripping tower through a pipeline, the top of the stripping tower is connected with the methyl ammonium washing condenser through a pipeline, and the connection part is arranged at the bottom of the washing section of the methyl ammonium washing condenser.
In an alternative embodiment, the stripping tower comprises a stripping column pipe and a stripping shell, wherein a stripping top end socket and a stripping bottom end socket are respectively arranged at the top end and the bottom end of the stripping column pipe, the metal pipe is connected with the side part of the stripping top end socket through a pipeline, and the top of the stripping top end socket is connected with the bottom of the washing section through a pipeline.
In an alternative embodiment, the condensing section comprises a heat exchanger comprising heat exchange tubes vertically arranged in a housing of the methylamine wash condenser, the vertical drum being connected to the housing by a conduit.
In an alternative embodiment, the cavity of the bottom head of the ammonium carbamate washing condenser is communicated with the heat exchange tube, and the bottom of the urea synthesis tower is connected with the bottom head of the ammonium carbamate washing condenser through a pipeline.
In an alternative embodiment, the urea synthesis column is connected to the bottom head of the methylamine washing condenser by a drain line, the high-pressure ejector is connected to the drain line, and the inlet of the high-pressure ejector is connected to the ammonia preheater by a line.
In an alternative embodiment, the medium pressure rectifying tower is connected with the bottom head of the stripping tower through a medium pressure reducing pipeline, so that urea synthesis liquid at the bottom of the stripping tower is decompressed and decomposed through the medium pressure rectifying tower, and the medium pressure reducing pipeline is connected with a stripping tower liquid level regulating valve for regulating the liquid level of the stripping tower.
In an alternative embodiment, the low-pressure rectifying tower is connected with the low-pressure decomposing system through a low-pressure reducing pipeline at the downstream, a medium-pressure tower liquid level regulating valve is arranged on the low-pressure reducing pipeline and used for regulating the liquid level of the medium-pressure rectifying tower, the bottom of the low-pressure rectifying tower is connected with the urine evaporator through a pipeline, the top of the low-pressure rectifying tower is sequentially connected with a low-pressure condenser and a low-pressure separator through a pipeline, the bottoms of the medium-pressure separator and the low-pressure separator are respectively provided with a medium-pressure methyl ammonium pump and a low-pressure methyl ammonium pump, the medium-pressure methyl ammonium pump and a discharging pipeline of the low-pressure methyl ammonium pump are combined and then connected with the methyl ammonium washing condenser, and the connecting part is arranged at the top of the washing section.
In an alternative embodiment, the urine evaporator comprises a urine evaporation tank and a urine heat exchanger which are distributed up and down, the urine evaporation tank is communicated with a tube side of the urine heat exchanger, the top of the medium-pressure rectifying tower is connected with the upper section of a shell of the urine heat exchanger through a pipeline, the upper section of a shell side of the urine heat exchanger is connected with the medium-pressure separator through a pipeline, and the lower section of the shell side of the urine heat exchanger supplements heat by adopting low-pressure steam.
In an alternative embodiment, the top of the methylamine washing condenser is connected with a high-pressure absorption tower through a pipeline, the bottom of the high-pressure absorption tower is connected with an atmospheric absorption tower through a pipeline and is connected to the side part of the top of the atmospheric absorption tower, and the middle-pressure separator is connected to the side part of the bottom of the atmospheric absorption tower after being combined with the gas phase pipeline of the low-pressure separator.
Through setting up middling pressure decomposition system, can realize hierarchical energy recuperation to retrieve the energy in the form of decomposition, energy utilization is more reasonable.
The high-pressure synthesis system only comprises a urea synthesis tower, a stripping tower, an ammonia preheater, a methyl ammonium washing condenser and a high-pressure ejector, so that the structural composition of the high-pressure system is simplified, the equipment quantity of a high-pressure loop is optimized, the investment is saved, the synthesis tower is arranged on the ground, the frame height of a urea device is reduced, and more heat is recovered.
The methylamine washing condenser comprises a washing section and a condensing section which are distributed up and down, can integrate condensation absorption and urea synthesis on the same equipment, is suitable for increasing the energy conservation of a urea device, is connected with a vertical steam drum on a shell of the condensing section, can absorb the heat of the condensing section, produces byproduct steam, is used for downstream one-section evaporation, and reduces the consumption of the downstream one-section evaporation steam.
Through setting up the baffling column plate in the inside of urea synthetic tower, combine the depressurization equipment that urea synthetic tower top low reaches set up, can make the reaction solution reach the top of the tower from the bottom of the tower through the baffling column plate from bottom to top in the urea synthetic tower, prolonged the residence time of urine in the urea synthetic tower, can improve urea conversion rate.
The baffle plates are alternately arranged along the axial direction of the urea synthesis tower at intervals, each baffle plate is a pore-free baffle plate, the flow path of urine in the urea synthesis tower can be increased, and the pore-free baffle plates can reduce the back mixing of the urine in the process of turning back the urine from bottom to top, so that the residence time of the urine in the urea synthesis tower is ensured.
The urea synthesis tower is internally filled with urine, the top of the urea synthesis tower is connected with a metal pipe, the urine flowing back to the bottom of the urea synthesis tower can be led out through the metal pipe, unreacted NH 3 and CO 2 are further decomposed, and the urea synthesis tower is further recycled after being washed and condensed by a methylamine washing condenser, so that the utilization rate of raw materials and the yield of urea are improved, and the reaction heat of a condensation section is further obtained.
The metal pipe comprises a bending pipe section, so that the urine flowing path of urine in the guiding process is prolonged, the urine guided out of the top of the tower is guided out through the metal pipe and flows downwards, and a good buffer effect can be achieved through the bending pipe section.
Through setting up metal pipe elbow section and vertical section as the relation with urea synthetic tower axial parallel, can control the urine and lead out the back and flow in vertical to prolonged flow time, be favorable to carrying out the dehydration reaction.
The urea synthesis device can realize the graded utilization of energy, achieve the aim of reducing energy consumption, and simultaneously achieve the technical aim of saving energy by optimizing a high-pressure reaction part, improving the reaction efficiency.
The urea synthesizing device and the related equipment adopt a hollow tower and a baffle plate with a non-porous baffle plate, a central pipe of the urea synthesizing tower moves outside the tower to increase the reaction space, the residence time of reaction materials is improved, and the reaction yield is improved. The ammonium carbamate washing condenser can absorb unreacted NH 3 and CO 2 in the ammonium carbamate liquid production process and continuously react to produce ammonium carbamate, and heat recovery equipment in the absorption process is integrated on the same equipment, so that the steam pair yield is improved.
The high-pressure reaction part is optimized through the measures, so that the reaction yield is improved, and the technical effects of saving energy, reducing consumption and improving the conversion rate are achieved. The energy is utilized in a grading way, and the steam consumption of each ton of urea is reduced by 20 percent.
Additional features and advantages of the application will be set forth in the detailed description which follows.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a urea synthesis device according to the present application;
FIG. 2 is a schematic diagram of the structure of a urea synthesizing tower and a metal pipe according to the present application;
FIG. 3 is a schematic diagram of the methylamine washing condenser according to the application.
Icon:
1-urea synthesis tower; 11-a metal tube; 12-a reaction liquid pipeline; 13-baffle plate; 14-vertical section;
2-stripping tower; 21-stripping column tube; 22-stripping shell; 23-stripping the top head; 24-stripping the bottom head;
3-methyl ammonium washes the condenser; 31-a washing section; 32-a condensing section; 33-heat exchanger; 34-ammonium carbamate washes the bottom end enclosure of the condenser; 35-a liquid discharge pipeline; 36-high pressure ejector;
4-a vertical steam drum;
a 5-ammonia preheater;
6-a medium-pressure rectifying tower; 61-medium pressure relief pipe; 62-stripper level regulating valve;
7-urine evaporator; 71-a urine evaporation tank; 72-urine heat exchanger;
8-a medium pressure separator;
9-a low-pressure rectifying tower; 91-a low pressure relief duct; 92-a medium pressure tower liquid level regulating valve; 93-a low pressure condenser; 94-low pressure separator;
10-medium pressure methylamine pump; 20-low pressure methylamine pump; 30-a high pressure absorption tower; 40-an atmospheric absorption tower.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are some, but not all, embodiments of the application. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
In the description of the present application, it should be noted that, the azimuth or positional relationship indicated by the terms "inner", "outer", etc. are based on the azimuth or positional relationship shown in the drawings, or the azimuth or positional relationship that is commonly put in use of the product of this application, are merely for convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element to be referred to must have a specific azimuth, be configured and operated in a specific azimuth, and therefore should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like, are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed", "connected" and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected or integrally 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 present application will be understood in specific cases by those of ordinary skill in the art.
The urea synthesis device and related equipment mainly perform urea synthesis, specifically, the self heat of the high-pressure synthesis part is simplified and optimized, so that the energy utilization is more reasonable, and based on the optimized structure and flow of the high-pressure synthesis system, the cyclic ammonium carbamate solution is used for washing and condensing NH 3 and CO 2 after the decomposition of the synthesis tower, and the generated heat release of ammonium carbamate is integrated on the same equipment, so that the byproduct steam quantity is improved, and the downstream steam consumption is reduced.
Referring to fig. 1 in combination with fig. 2-3, the urea synthesis apparatus of the present invention comprises a high pressure synthesis system, a medium pressure decomposition system, a low pressure decomposition system, and a urine evaporator.
The high-pressure synthesis system comprises a urea synthesis tower 1, a stripping tower 2, a methyl ammonium washing condenser 3, an ammonia preheater 5 and a high-pressure ejector 36, and only five devices, namely the urea synthesis tower 1, the stripping tower 2, the methyl ammonium washing condenser 3, the ammonia preheater 5 and the high-pressure ejector 36 are arranged by optimizing the flow and the structural composition of the high-pressure synthesis system, so that investment is saved, the urea synthesis tower 1 is arranged on the ground, and the frame height of a urea device is reduced.
The ammonium carbamate wash condenser 3 simultaneously performs wash condensation of NH 3 and CO 2 after decomposition in the urea synthesis column 1 and exothermic reaction of ammonium carbamate formation. The two angles are specifically carried out in the methyl ammonium washing condenser 3, the methyl ammonium washing condenser 3 comprises a washing section 31 and a condensing section 32 which are distributed up and down, urine in the urea synthesis tower 1 is decomposed into NH 3 and CO 2 through a metal pipe 11, then enters the bottom of the washing section 31 through the top of the stripping tower 2, and NH 3 and CO 2 are washed in the washing section 31 through circulating methyl ammonium liquid downstream of the urea synthesis device, and methyl ammonium synthesis reaction is carried out in the condensing section 32.
The methylamine synthesis reaction carried out by the condensing section 32 generates a large amount of heat, the vertical steam drum 4 is connected to the shell of the condensing section 32 and is mainly used for absorbing the generated heat of the methylamine synthesis reaction, desalted water conveyed outside is fed into the vertical steam drum 4 to be converted into steam after absorbing the heat, and the steam condensate with higher temperature in the vertical steam drum 4 can be further by-produced with high-quality low-pressure steam by combining the absorbed heat, so that the steam can meet the heating requirement of the subsequent process, a high-water-regulating system is omitted, the flow is simplified, and the investment of the device is reduced.
The medium pressure decomposition system comprises a medium pressure rectifying tower 6, a medium pressure separator 8 and a connecting pipeline, and the medium pressure decomposition system can enable medium pressure flash steam in the medium pressure decomposition system to enter a urine evaporator 7 for heat recovery, so that the consumption of steam of the device is reduced, the medium pressure system is not provided with a medium water regulating system, the flow is simplified, the number of equipment is reduced, and the consumption of urea steam per ton is reduced by 20 percent through the invention.
The urea synthesis tower 1 is a vertical tower and comprises a high-pressure reactor composed of a metal shell, an internal tray and a metal pipe, wherein the internal tray comprises a plurality of baffle plates 13 arranged in the urea synthesis tower 1, and the baffle plates 13 are arranged alternately along the axial direction of the urea synthesis tower 1, so that urine can flow from bottom to top in the urea synthesis tower 1 and pass through the baffle plates 13, the flow path of reaction liquid in the urea synthesis tower 1 is prolonged, the residence time of the reaction liquid in the urea synthesis tower 1 is ensured, and the conversion rate of urea is improved.
Each baffle plate 13 is a non-porous baffle plate, so that the reaction liquid is prevented from backmixing in the process of turning back and flowing, urine is filled in the urea synthesis tower 1, the flowing state of the existing reaction liquid can be improved by turning back and flowing the urine from bottom to top in the urea synthesis tower 1 through the baffle plates 13, the internal space and the external size of the urea synthesis tower 1 can be reduced, and the equipment cost is reduced.
In order to lead out and decompose the reacted urine, unreacted NH 3 and CO 2 are separated out from the urine and decomposed, the top of the urea synthesis tower 1 is connected with a metal pipe 11, the metal pipe 11 comprises a bent pipe section, and the flow path outside the urea synthesis tower 1 after the urine flows out can be increased, so that a dehydration space is provided.
Urine in the urea synthesis tower 1 flows back to the top of the tower, is guided out through the metal pipe 11 and flows downwards, so that the buffer effect of the urine after guiding out can be maintained, and the dehydration reaction can be facilitated.
The vertical section 14 of the bent pipe section of the metal pipe is in axial parallel relation with the urea synthesis tower, and the vertical section is further combined with the urea synthesis tower in axial parallel, so that urine can be controlled to flow vertically after being led out, the flowing time is prolonged, and the full and thorough dehydration reaction is ensured.
The vertical section 14 of the metal pipe 11 is connected with the side wall of the urea synthesis tower 1 through the support frame, so that the urea synthesis tower 1 is mounted, and the metal pipe 11 and a downstream butt joint pipeline are connected and mounted conveniently.
In one particular embodiment, in order to enable the urine in the urea synthesis column 1 to be decomposed into NH 3 and CO 2 in the metal pipe 11, the metal pipe 11 is connected to the top of the stripping column 2 by a pipe, enabling the decomposed NH 3 and CO 2 to enter the top of the stripping column 2 and to enter the methylamine wash condenser 3 through the top of the stripping column 2 for wash condensation.
Specifically, the metal pipe 11 is connected to the top of the urea synthesis column 1 to be able to lead out the urine material in the urea synthesis column 1.
The top of the stripping tower 2 is connected with the methyl ammonium washing condenser 3 through a pipeline, and the connection part is arranged at the bottom of the washing section 31 in the methyl ammonium washing condenser 3, so that NH 3 and CO 2 which are decomposed in the metal pipe 11 and pass through the top of the stripping tower 2 can enter the bottom of the washing section 31 of the methyl ammonium washing condenser 3 through the arrangement mode, and effective washing condensation is obtained.
It should be noted that, besides the urea synthesis tower with the vertical tower structure, the urea synthesis tower can also be a structure of a horizontal tower, and baffling tower plates are required to be arranged in the urea synthesis tower of the horizontal tower, so that the baffling tower plates without holes are arranged in a staggered way along the axial direction, thereby meeting the requirements of prolonging the flow path of the reaction liquid in the urea synthesis tower and ensuring the residence time. Meanwhile, the metal pipe can guide urine out from the end part of the horizontal urea synthesis tower, is bent for a certain length relative to the urea synthesis tower horizontally, and is connected with the top of the stripping tower through a pipeline, so that the resolved NH 3 and CO 2 enter the ammonium carbamate washing condenser through the stripping tower.
The stripping tower 2 comprises a stripping column tube 21 and a stripping shell 22, wherein a stripping top end socket 23 and a stripping bottom end socket 24 are respectively arranged at the top end and the bottom end of the stripping column tube 21, the metal tube 11 is connected with the side part of the stripping top end socket 23 through a pipeline, the top part of the stripping top end socket 23 is connected with the bottom part of the washing section 31 through a pipeline, NH 3 and CO 2 decomposed in the metal tube 11 on the urea synthesis tower 1 are used for entering the inside of the stripping top end socket 23 from the side part of the stripping top end socket 23, and enter the methyl ammonium washing condenser 3 through the top part of the stripping top end socket 23.
The condensing section 32 comprises a heat exchanger 33, the heat exchanger 33 comprises heat exchange tubes which are vertically arranged in the shell of the methylamine washing condenser 3, and the vertical drum 4 is connected with the shell through a pipeline.
Specifically, the tube side of the heat exchanger 33 is communicated with the washing section 31, the washing condensed material can enter the reaction tube of the heat exchanger 33 and carry out the ammonium carbamate synthesis reaction to release heat, the vertical steam drum 4 is connected with the shell through a pipeline, the desalted water introduced into the vertical steam drum 4 is combined, the desalted water can absorb the reaction heat and is converted into steam, the steam circulates between the vertical steam drum 4 and the shell of the ammonium carbamate washing condenser 3, the vertical steam drum 4 is connected with a condensate pipeline, and high-quality low-pressure steam can be obtained by further reducing the pressure and flash evaporation of the steam condensate in the vertical steam drum 4, so that the recovery of the heat in the high-pressure synthesis system is realized.
The methyl ammonium washing condenser 3 also comprises a methyl ammonium washing condenser bottom end socket 34 positioned at the bottom, the cavity of the methyl ammonium washing condenser bottom end socket 34 is communicated with the reaction tube, and the bottom of the urea synthesis tower 1 is connected with the methyl ammonium washing condenser bottom end socket 34 through a reaction liquid pipeline 12.
The circulating methyl ammonium solution downstream of the urea synthesis plant washes the unreacted NH 3 and CO 2 gas phase, and the wash solution descends through a funnel comprised in the wash section 31 of the methyl ammonium wash condenser 3 and descends through a reaction tube to the methyl ammonium wash condenser bottom head 34 of the methyl ammonium wash condenser 3.
Besides the condensation washing, the liquid level balance between the urea synthesis tower 1 and the methyl ammonium washing condenser 3 can be established based on the connection between the bottom of the urea synthesis tower 1 and the bottom head 34 of the methyl ammonium washing condenser through the reaction liquid pipeline 12, so that the reaction liquid pipeline 12 plays a role of a balance pipe.
The gas in the stripping tower 2 enters the methyl ammonium washing condenser 3 from the top of the stripping tower 2 to be contacted with methyl ammonium liquid, thereby forming the methyl ammonium synthesis reaction at the position of the heat exchanger 33, and a large amount of heat is released in the reaction process for byproduct low-pressure steam for subsequent urine processing, and the redundant low-pressure steam is externally supplied.
From the viewpoint of returning the reaction liquid in the methylamine washing condenser 3 to the urea synthesis tower 1, the urea synthesis tower 1 and the bottom head 34 of the methylamine washing condenser are connected by a drain pipe 35, specifically, both ends of the reaction liquid pipe 12 are respectively connected to the bottom centers of the urea synthesis tower 1 and the bottom head 34 of the methylamine washing condenser, one end of the drain pipe 35 is connected to the side of the bottom head 34 of the methylamine washing condenser, the other end is connected to the side wall of the middle lower stage of the urea synthesis tower 1, and a high-pressure injector 36 is provided on the drain pipe 35, and the reaction liquid returned from the bottom head 34 of the methylamine washing condenser to the urea synthesis tower 1 is further dehydrated by being pressurized by the high-pressure injector 36 and then enters the urea synthesis tower 1.
The inlet of the high-pressure injector 36 is connected to the ammonia preheater 5 via a pipe, and since the ammonia preheater 5 preheats the liquid ammonia, the high-pressure injector 36 can inject the liquid ammonia into the urea synthesis tower 1 under pressure while maintaining the heat balance in the urea synthesis tower 1.
In the high-pressure synthesis system, high-pressure CO 2 gas from a carbon dioxide compressor is sent to a stripping tower 2, medium-pressure steam of 2.5MPa (A) is adopted to heat the shell side of the stripping tower 2, and the methyl ammonium in reaction liquid from a urea synthesis tower 1 is decomposed into NH 3 and CO 2 gas in a metal pipe 11, and the NH 3 and CO 2 gas are sent to the bottom inlet of a washing section 31 of a high-pressure methyl ammonium washing condenser 3 from the top of the stripping tower 2 through a pipeline.
In the reaction process, the reaction liquid of the urea synthesis tower 1 flows into the stripping tower 2 through the metal pipe 11 by utilizing the pressure difference, unreacted NH 3、CO2 and inert gas are sent into the methylamine washing condenser 3 for condensation absorption, and unreacted NH 3、CO2 and inert gas flowing out of the stripping tower 2 enter the medium-pressure decomposition system.
By combining the urea synthesis tower 1, the stripping tower 2 and the methylamine washing condenser 3 with the metal pipe 11, the reaction liquid pipe 12, the liquid discharge pipe 35 and the high-pressure ejector 36, dynamic balance can be established among the urea synthesis tower 1, the stripping tower 2 and the methylamine washing condenser 3, and absorption and utilization of heat generated in the synthesis process can be realized.
Meanwhile, urine in the urea synthesis tower 1 is led out through the metal pipe 11, the urine after full reaction is separated by depressurization and separation, unreacted NH 3 and CO 2 gas are separated out, and the gas is circularly returned to the urea synthesis tower 1 after washing and condensation, so that the condition of heat production hidden in the urea synthesis process can be further created while the full reaction is enhanced, high-quality low-pressure steam is produced by side, and the energy consumption in the urea synthesis process is reduced from another angle.
The operating conditions of the high pressure methylamine wash condenser 3 are: 14.1MPa (A), 181 ℃, and the conversion rate of CO 2 is about 40-42%; operating conditions of urea synthesis column 1: 14.3 The conversion rate of CO 2 at 183 ℃ under MPa (A) is about 60-63%.
The medium pressure decomposition system comprises a medium pressure rectifying tower 6, a medium pressure separator 8 and connecting pipelines thereof, wherein the medium pressure rectifying tower 6 is connected with a stripping bottom sealing head 24 through a medium pressure reducing pipeline 61, so that urea synthesis liquid at the bottom of the stripping tower 2 is decompressed and decomposed through the medium pressure rectifying tower 6, and a stripping tower liquid level regulating valve 62 is arranged on the medium pressure reducing pipeline 61.
The urea synthesis solution from the stripping tower 2 is decompressed to about 2.2-2.3MPa (A) through a stripping tower liquid level regulating valve 62, 158 ℃ and then is fed into a medium-pressure rectifying tower 6, the medium-pressure rectifying tower 6 is a falling film type heater, and the urine discharged from the medium-pressure rectifying tower 6 is decompressed and then is conveyed to a subsequent low-pressure decomposition system.
The low pressure rectifying column 9 is connected to the low pressure rectifying column 6 through the low pressure reducing pipeline 91 at the downstream, the medium pressure column liquid level regulating valve 92 is arranged on the low pressure reducing pipeline 91, the bottom of the low pressure rectifying column 9 is connected with the urine evaporating pot 71 through a pipeline, the low pressure condenser 93 and the low pressure separator 94 are sequentially connected to the top of the low pressure rectifying column 9 through a pipeline, the medium pressure separator 8 and the low pressure separator 94 are respectively provided with the medium pressure methylamine pump 10 and the low pressure methylamine pump 20 at the bottom, the medium pressure methylamine pump 10 and the discharging pipeline of the low pressure methylamine pump 20 are combined and then connected with the methylamine washing condenser 3, and the connecting part is arranged at the top of the washing section 31.
Urine from the medium-pressure rectifying tower 6 enters the low-pressure rectifying tower 9 through a low-pressure decompression pipeline 91 under the action of a medium-pressure tower liquid level regulating valve 92 to be decompressed to 0.45-0.5 MPa (A), most of carbon dioxide and ammonia in the solution are flashed, the temperature of the solution is reduced from 158 ℃ to 115 ℃, and a gas-liquid mixture enters the top of the low-pressure rectifying tower 9.
The upper part of the low-pressure rectifying tower 9 is a packed tower, which plays a role in gas rectification. The lower part is a separator, urea methyl ammonium liquid falling through the filler section flows into a heater at the bottom of the low-pressure rectifying tower 9, 0.58MPa (A) steam which is a byproduct of the high-pressure methyl ammonium washing condenser 3 is adopted for heating, the temperature is raised to 135 ℃, the methyl ammonium is further decomposed, and then the liquid of the low-pressure rectifying tower 9 is returned to the urine evaporating pot 71 for heating concentration.
The gas of the low-pressure rectifying tower 9 rises to a rectifying tower filling section, the rectified gas is led out of the low-pressure rectifying tower 9 from the tower top and is sent to the immersed low-pressure condenser 93 for condensation absorption, the tube side of the immersed low-pressure condenser 93 is connected with a circulating water pipeline, and heat generated by absorption is directly taken away by circulating cooling water.
The gas-liquid mixture overflows from the upper portion of the submerged low-pressure condenser 93 to the low-pressure separator 94, and is subjected to gas-liquid separation. The liquid in the low-pressure separator 94 is led out from the bottom of the low-pressure separator 94, is boosted to 2.8MPa (a) or more by the low-pressure methylamine pump 20, and is combined with the liquid in the medium-pressure separator 8 fed by the medium-pressure methylamine pump 10 and returned to the high-pressure methylamine condenser. The gas separated by the low-pressure separator 94 enters the normal-pressure absorption tower 40, and is discharged through the continuous discharge cylinder after being absorbed by the normal-pressure absorption tower 40 to meet the environmental protection requirement.
The urine evaporator 7 comprises a urine evaporation tank 71 and a urine heat exchanger 72 which are distributed up and down, wherein the urine evaporation tank 71 is mainly used for receiving the bottom liquid phase of the low-pressure rectifying tower 9, the urine evaporation tank 71 is communicated with the tube side of the urine heat exchanger 72, the top of the medium-pressure rectifying tower 6 is connected with the shell side of the urine heat exchanger 72 through a pipeline, and the shell side of the urine heat exchanger 72 is connected with the medium-pressure separator 8 through a pipeline.
The gas discharged from the top of the medium pressure rectifying tower 6 enters the heat energy recovery section of the urine evaporator 7, namely enters the urine heat exchanger 72 of the urine evaporator 7, further enters the shell side of the urine heat exchanger 72, heats the urine in the urine heat exchanger 72 of the urine evaporator 7, and provides heat for pre-concentration of the urine.
Further, the gas-liquid mixture after heat exchange is completed enters the medium-pressure separator 8 through a pipeline connected with the shell side of the urine heat exchanger 72 for gas-liquid separation, the liquid phase in the medium-pressure separator 8 is boosted by the medium-pressure methylamine pump 10 and then is sent to the high-pressure methylamine washing condenser 3, and the gas phase is absorbed by the liquid phase of the medium-pressure separator 8 and is sent to the normal-pressure absorption tower 40 for absorption after being decompressed and then is vented.
From the exhaust emission perspective, the top of the ammonium carbamate washing condenser 3 is connected with the high-pressure absorption tower 30 through a pipeline, a pressure reducing valve is arranged on the pipeline, the bottom of the high-pressure absorption tower 30 is connected with the normal-pressure absorption tower 40 through a pipeline and is connected to the top side part of the normal-pressure absorption tower 40, the gas phase pipelines of the medium-pressure separator 8 and the low-pressure separator 94 are combined and then are connected to the bottom side part of the normal-pressure absorption tower 40, and the gas phases in the medium-pressure separator 8 and the low-pressure separator 94 are combined and introduced into the normal-pressure absorption tower 40 for absorption.
By this arrangement, the liquid in the high-pressure absorption tower 30 can be sprayed in the normal-pressure absorption tower 40, and the gas phase in the medium-pressure separator 8 and the low-pressure separator 94 can be sprayed and recovered.
According to the urea synthesis device, the whole energy consumption of the device is effectively reduced by improving the flow and the structure of the existing high-pressure synthesis system, the balance of the energy in the device is realized, the equipment cost is reduced, and the productivity of urea is improved.
It should be noted that the features of the embodiments of the present application may be combined with each other without conflict.
The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. The urea synthesis device is characterized by comprising a high-pressure synthesis system, a medium-pressure decomposition system, a low-pressure decomposition system and a urine evaporator;
The high-pressure synthesis system comprises a urea synthesis tower, a stripping tower, an ammonia preheater, a methyl ammonium washing condenser and a high-pressure ejector which are connected through a pipeline;
The methylamine washing condenser comprises a washing section and a condensing section which are distributed up and down, and a vertical steam drum is connected to a shell of the condensing section;
The medium-pressure decomposition system comprises a medium-pressure rectifying tower, a medium-pressure separator and a connecting pipeline, and the low-pressure decomposition system comprises a low-pressure rectifying tower, a low-pressure separator and a connecting pipeline;
The urea synthesis tower is a vertical tower and comprises a high-pressure reactor composed of a metal shell, an internal tray and metal pipes, wherein the internal tray comprises a plurality of baffle plates which are alternately arranged along the axial direction of the urea synthesis tower at intervals, each baffle plate is a non-porous baffle plate, the urea synthesis tower is filled with urine, and the urine flows back from bottom to top through the baffle plates in the urea synthesis tower;
The metal pipe is connected to the top of the urea synthesis tower, the metal pipe comprises a bent pipe section, urine in the urea synthesis tower flows back to the top of the tower and is guided out through the metal pipe and flows downwards, the metal pipe comprises a metal pipe horizontal section and a metal pipe vertical section, and the metal pipe vertical section is arranged in parallel with the urea synthesis tower in the axial direction.
2. The urea synthesis device according to claim 1, wherein the metal pipe is connected to the top of the stripping column via a pipe, the top of the stripping column is connected to the methylamine washing condenser via a pipe, and the connection part is arranged at the bottom of the washing section of the methylamine washing condenser.
3. The urea synthesis device according to claim 1, wherein the stripping tower comprises a stripping column tube and a stripping shell, the top and bottom ends of the stripping column tube are respectively provided with a stripping top end socket and a stripping bottom end socket, the metal tube is connected with the side part of the stripping top end socket through a pipeline, and the top of the stripping top end socket is connected with the bottom of the washing section through a pipeline.
4. Urea synthesis plant according to claim 1, characterized in that the condensation section comprises a heat exchanger comprising heat exchange tubes arranged vertically in the shell of the methylamine wash condenser, the vertical drum being connected to the shell by a pipe.
5. The urea synthesis device according to claim 4, wherein the cavity of the bottom head of the ammonium carbamate washing condenser is communicated with the heat exchange pipe, and the bottom of the urea synthesis tower is connected with the bottom head of the ammonium carbamate washing condenser through a pipeline.
6. The urea synthesis device according to claim 5, characterized in that the urea synthesis column is connected to the bottom head of the ammonium carbamate wash condenser by a drain pipe, the high-pressure ejector is connected to the drain pipe, and the inlet of the high-pressure ejector is connected to the ammonia preheater by a pipe.
7. A urea synthesis plant according to claim 3, wherein the medium pressure rectifying column is connected to the bottom head of the stripping column via a medium pressure reducing pipe for reducing the pressure of the urea synthesis liquid at the bottom of the stripping column via the medium pressure rectifying column, and the medium pressure reducing pipe is connected to a stripping column liquid level regulating valve for regulating the liquid level of the stripping column.
8. The urea synthesis device according to claim 7, wherein the downstream of the medium pressure rectifying tower is connected with the low pressure decomposition system through a low pressure reducing pipeline, a medium pressure tower liquid level regulating valve is arranged on the low pressure reducing pipeline for regulating the liquid level of the medium pressure rectifying tower, the bottom of the low pressure rectifying tower is connected with the urine evaporator through a pipeline, the top of the low pressure rectifying tower is sequentially connected with a low pressure condenser and a low pressure separator through a pipeline, the bottoms of the medium pressure separator and the low pressure separator are respectively provided with a medium pressure methylamine pump and a low pressure methylamine pump, the discharging pipelines of the medium pressure methylamine pump and the low pressure methylamine pump are combined and then connected with the methylamine washing condenser, and the connection part is arranged at the top of the washing section.
9. The urea synthesis device according to claim 8, wherein the urine evaporator comprises a urine evaporation tank and a urine heat exchanger which are vertically distributed, the urine evaporation tank is communicated with a tube side of the urine heat exchanger, the top of the medium pressure rectifying tower is connected with an upper section of a shell of the urine heat exchanger through a pipeline, an upper section of a shell side of the urine heat exchanger is connected with the medium pressure separator through a pipeline, and a lower section of the shell side of the urine heat exchanger supplements heat by low pressure steam.
10. Urea synthesis plant according to claim 9, characterized in that the top of the methyl ammonium washing condenser is connected with a high-pressure absorption tower through a pipeline, the bottom of the high-pressure absorption tower is connected with an atmospheric absorption tower through a pipeline and is connected to the top side of the atmospheric absorption tower, and the medium-pressure separator is combined with the gas phase pipeline of the low-pressure separator and then is connected to the bottom side of the atmospheric absorption tower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411467920.4A CN118988206B (en) | 2024-10-21 | 2024-10-21 | Urea synthesis device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202411467920.4A CN118988206B (en) | 2024-10-21 | 2024-10-21 | Urea synthesis device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN118988206A true CN118988206A (en) | 2024-11-22 |
| CN118988206B CN118988206B (en) | 2025-01-21 |
Family
ID=93474641
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202411467920.4A Active CN118988206B (en) | 2024-10-21 | 2024-10-21 | Urea synthesis device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118988206B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1074901A (en) * | 1992-12-23 | 1993-08-04 | 中国五环化学工程公司 | Producing urea with increased yield by stripping with CO 2 novel process and device |
| CN2930849Y (en) * | 2006-07-04 | 2007-08-08 | 大连松海石化检修工程有限公司 | Radial flow type urea synthetic tower |
| US20230118984A1 (en) * | 2020-02-25 | 2023-04-20 | Casale Sa | Process and plant for the synthesis of urea |
| CN118718905A (en) * | 2023-07-21 | 2024-10-01 | 丁泽华 | A horizontal urea synthesis reactor and urea synthesis high-pressure circle equipment and process |
| CN118750896A (en) * | 2024-06-14 | 2024-10-11 | 中国五环工程有限公司 | An energy-saving urea production system |
-
2024
- 2024-10-21 CN CN202411467920.4A patent/CN118988206B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1074901A (en) * | 1992-12-23 | 1993-08-04 | 中国五环化学工程公司 | Producing urea with increased yield by stripping with CO 2 novel process and device |
| CN2930849Y (en) * | 2006-07-04 | 2007-08-08 | 大连松海石化检修工程有限公司 | Radial flow type urea synthetic tower |
| US20230118984A1 (en) * | 2020-02-25 | 2023-04-20 | Casale Sa | Process and plant for the synthesis of urea |
| CN118718905A (en) * | 2023-07-21 | 2024-10-01 | 丁泽华 | A horizontal urea synthesis reactor and urea synthesis high-pressure circle equipment and process |
| CN118750896A (en) * | 2024-06-14 | 2024-10-11 | 中国五环工程有限公司 | An energy-saving urea production system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN118988206B (en) | 2025-01-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101918357B (en) | Process and plant for urea production | |
| CA2871724C (en) | Method and apparatus for the production of urea from ammonia and carbon dioxide | |
| US10376859B2 (en) | Urea production with bi-pressurized synthesis | |
| CN104829494B (en) | A kind of energy-saving carbamide production system and production technology thereof | |
| JP3811523B2 (en) | Integrated ammonia / urea method | |
| US20090062566A1 (en) | Apparatus for synthesizing urea and method for revamping the same | |
| CN109890788B (en) | Integrated process of urea and urea-ammonium nitrate | |
| JP2022508407A (en) | Plants with thermal integration in urea production process and low pressure recovery section | |
| US7579502B2 (en) | Apparatus for synthesizing urea | |
| EA035936B1 (en) | Urea manufacturing method and urea manufacturing apparatus | |
| JPWO2017043390A1 (en) | Urea manufacturing method and urea manufacturing apparatus | |
| CN103570588A (en) | Urea synthesis device and urea synthesis method | |
| CN105026365B (en) | Urea synthesis method and equipment | |
| CN101492398B (en) | Urea production process of high-efficiency condensation, low-mounting height CO2 air stripping method and high-voltage lamp type full condensation reactor | |
| KR20000062909A (en) | Method for modernizing a urea production plant | |
| JP4191879B2 (en) | Urea synthesis method and apparatus | |
| SU602115A3 (en) | Method of obtaining urea | |
| CN118750896A (en) | An energy-saving urea production system | |
| SU1450735A3 (en) | Method of producing carbamide | |
| CN118988206B (en) | Urea synthesis device | |
| CN118718905A (en) | A horizontal urea synthesis reactor and urea synthesis high-pressure circle equipment and process | |
| CN116897076B (en) | Urea production process and plant with parallel MP units | |
| CA2743659C (en) | Improvement to the high-pressure loop in a process for synthesis of urea | |
| CN111995592B (en) | Method and device for co-production of urea and melamine | |
| EP3939963B1 (en) | Urea production method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |