CN118286997B - Urea synthesis system and synthesis method - Google Patents
Urea synthesis system and synthesis method Download PDFInfo
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- CN118286997B CN118286997B CN202410361532.1A CN202410361532A CN118286997B CN 118286997 B CN118286997 B CN 118286997B CN 202410361532 A CN202410361532 A CN 202410361532A CN 118286997 B CN118286997 B CN 118286997B
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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
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0046—Sequential or parallel reactions, e.g. for the synthesis of polypeptides or polynucleotides; Apparatus and devices for combinatorial chemistry or for making molecular arrays
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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
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0006—Controlling or regulating processes
- B01J19/0013—Controlling the temperature of the process
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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
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0053—Details of the reactor
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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
- B01J2/02—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops
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- 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
- C07C273/04—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 from carbon dioxide and ammonia
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- 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
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Abstract
本发明涉及尿素生产技术领域，具体公开了一种尿素合成系统及合成方法，合成系统包括原料供给单元、反应单元、气相循环单元和液相循环单元，原料供给单元用于提供液氨和二氧化碳，反应单元包括卧式反应器和合成塔，原料供给单元的输出端与卧式反应器的进料端连接，卧式反应器的出料端与合成塔的进料端连接，合成塔设有出气端和出液端，气相循环单元用于对生产过程中产生的氨气和二氧化碳进行循环利用，合成塔的出气端与气相循环单元连接，合成塔的出液端与液相循环单元连接，液相循环单元用于对反应产物提纯以得到尿素，本发明提供的尿素合成系统可以提高尿素合成生产的效率，提高尿素产量。
The invention relates to the technical field of urea production, and specifically discloses a urea synthesis system and a synthesis method. The synthesis system comprises a raw material supply unit, a reaction unit, a gas phase circulation unit and a liquid phase circulation unit. The raw material supply unit is used to provide liquid ammonia and carbon dioxide. The reaction unit comprises a horizontal reactor and a synthesis tower. The output end of the raw material supply unit is connected with the feed end of the horizontal reactor, the discharge end of the horizontal reactor is connected with the feed end of the synthesis tower, the synthesis tower is provided with a gas outlet end and a liquid outlet end, the gas phase circulation unit is used to recycle ammonia and carbon dioxide generated in the production process, the gas outlet end of the synthesis tower is connected with the gas phase circulation unit, the liquid outlet end of the synthesis tower is connected with the liquid phase circulation unit, the liquid phase circulation unit is used to purify the reaction product to obtain urea. The urea synthesis system provided by the invention can improve the efficiency of urea synthesis production and increase the urea yield.
Description
Technical Field
The invention relates to the technical field of urea production, in particular to a urea synthesis system and a urea synthesis method.
Background
In the related art, when urea is produced, liquid ammonia and carbon dioxide react under the conditions of high pressure and certain temperature to generate urea, a synthesis tower is used as reaction equipment, and the total reaction formula is as follows: 2NH3 (liquid) +CO2 (gas) +.CO (NH 2) 2 (liquid) +H2O (liquid);
in the actual production process, liquid ammonia and carbon dioxide do not directly generate urea which is a target product, the liquid ammonia and the carbon dioxide react in two steps to generate urea, the first step generates intermediate product ammonium carbamate, abbreviated as methyl ammonium, from the liquid ammonia and the carbon dioxide, the methyl ammonium dehydrates to generate urea, and the first step generates liquid methyl ammonium from the liquid ammonia and the carbon dioxide: 2 NH3+CO2.about.NH2COONH 4, which is a reversible strongly exothermic reaction; the second step is to dehydrate liquid methyl ammonium to generate urea: NH2COONH4 is about CO (NH 2) 2+H2O, the reaction is a reversible micro-endothermic reaction, the reaction speed is relatively slow, the reaction is a control step of the reaction, the balance needs to be achieved for a long time, in the related production technology, the two steps are usually completed in a synthesis tower under the conditions of high pressure (such as 13.8-20.5 MPa) and high temperature (such as 180-200 ℃), the two steps have different heat requirements, the degree of converting liquid ammonia and carbon dioxide into methyl ammonium in the first step of reaction is lower under the same reaction condition, and the yield of the obtained final product urea is not ideal.
Disclosure of Invention
The invention provides a urea synthesis system and a urea synthesis method, which aim to solve the problems that the urea synthesis reaction in the related art is influenced by temperature and environment, intermediate reaction products are reduced, and the synthesis efficiency and yield of a final product urea are influenced.
The urea synthesis system of the present invention comprises:
A raw material supply unit for supplying liquid ammonia and carbon dioxide required for urea production;
the reaction unit is used for providing corresponding reaction equipment according to the reaction conditions of raw materials, the reaction equipment comprises a horizontal reactor and a synthesis tower, the output end of the raw material supply unit is connected with the feeding end of the horizontal reactor, the discharging end of the horizontal reactor is connected with the feeding end of the synthesis tower, and the synthesis tower is provided with an air outlet end for discharging air and a liquid outlet end for discharging liquid;
the gas phase circulation unit is used for recycling ammonia and carbon dioxide generated in the production process, and the gas outlet end of the synthesis tower is connected with the gas phase circulation unit;
And the liquid phase circulation unit is connected with the liquid outlet end of the synthesis tower and is used for purifying reaction products to obtain urea.
Preferably, the gas-phase circulation unit comprises a medium-pressure methylamine condenser and a medium-pressure methylamine liquid level tank, wherein the discharge end of the medium-pressure methylamine condenser is connected with the feed end of the medium-pressure methylamine liquid level tank, the medium-pressure methylamine liquid level tank is connected with the horizontal reactor through a high-pressure methylamine pump, the discharge end of the medium-pressure methylamine liquid level tank is connected with the feed end of the high-pressure methylamine pump, the discharge end of the high-pressure methylamine pump is connected with the feed end of the horizontal reactor, the horizontal reactor is provided with a liquid inlet for butt joint of the medium-pressure methylamine liquid level tank, and the discharge end of the medium-pressure methylamine liquid level tank is connected with the liquid inlet of the horizontal reactor.
Preferably, the liquid phase circulation unit comprises a carbon dioxide stripping tower, a medium pressure flash tank, a medium pressure methylamine separator, a medium pressure rectification tower and a low pressure rectification tower, wherein the liquid outlet end of the synthesis tower is connected with the carbon dioxide stripping tower, the liquid outlet end of the carbon dioxide stripping tower is connected with the feed end of the medium pressure flash tank, the gas outlet end of the medium pressure flash tank is connected with the medium pressure rectification tower, a heat dissipation mechanism is arranged in the horizontal reactor, the liquid outlet end of the medium pressure flash tank enters the heat dissipation mechanism of the horizontal reactor and absorbs heat in the horizontal reactor, the liquid outlet end of the medium pressure flash tank enters the medium pressure methylamine separator after circulating through the horizontal reactor, the liquid outlet end of the medium pressure methylamine separator is connected with the gas phase circulation unit, the liquid outlet end of the medium pressure methylamine separator is connected with the medium pressure rectification tower, the liquid outlet end of the medium pressure rectification tower is connected with the gas phase circulation unit, the liquid outlet end of the medium pressure rectification tower is connected with the low pressure rectification tower, the low pressure rectification tower is connected with the low pressure evaporation and low pressure recovery system, and the low pressure granulation tower is used for the final granulation and low pressure recovery of the low pressure granulation tower;
and the synthesis tower, the medium-pressure methylamine separator and the gas outlet end of the medium-pressure rectifying tower are all connected with the medium-pressure methylamine condenser.
Preferably, the raw material supply unit comprises a carbon dioxide compressor and an ammonia pump, the carbon dioxide compressor is connected with the carbon dioxide stripping tower, the air outlet end of the carbon dioxide stripping tower is connected with the horizontal reactor, and the ammonia pump is connected with the horizontal reactor through a liquid ammonia preheater.
Preferably, the horizontal reactor comprises:
a housing in which a space for reaction of raw materials is formed;
The heat exchange mechanism is detachably connected with two axial ends of the shell, two groups of heat exchange mechanisms are arranged at any axial end of the shell, each group of heat exchange mechanisms independently operates, any heat exchange mechanism comprises a plurality of radiating pipes, each radiating pipe is U-shaped, and each radiating pipe is independently detached and connected with the shell.
Preferably, end cover plates are detachably mounted at two ends of the shell, each radiating pipe is connected with the end cover plate through a plugging component, a plurality of mounting grooves are formed in the end cover plate, each plugging component is arranged in each mounting groove one by one so as to be towards one side inside the shell, and each plugging component comprises a plugging piece, a cleaning piece and a fixing piece which are sequentially arranged from inside to outside;
The two plugging pieces are hinged with the mounting groove, the inner sides of the mounting groove are plugged when the two plugging pieces are in butt joint, the cleaning piece is in sliding connection with the mounting groove, the two plugging pieces are connected with the cleaning piece through a first elastic piece, the direction of pulling force of the first elastic piece acting on the cleaning piece faces the plugging piece, and the pulling force of the cleaning piece, which is stressed by the first elastic piece, is increased when the cleaning piece is far away from the plugging piece;
The mounting groove is fixed relatively, the cleaning piece is connected with the mounting groove through the second elastic piece, the thrust acting on the cleaning piece by the second elastic piece faces the blocking piece, and the blocking piece is increased by the thrust of the second elastic piece when being close to the mounting groove.
Preferably, the cleaning piece comprises a movable frame and two cleaning plates, the movable frame is attached to the mounting groove to slide, the two cleaning plates are arranged on the inner side of the movable frame, the two cleaning plates are hinged to the upper side wall and the lower side wall of the movable frame through torsion springs, semicircular gaps are formed in the two cleaning plates, and round holes for the radiating pipes to pass through are formed in the butt joint of the two cleaning plates.
Preferably, the collecting assembly used for collecting the solution in the mounting groove is further arranged in the mounting groove, the collecting assembly comprises a collecting groove, the upper side of the collecting groove is provided with a communication port communicated with the mounting groove, the collecting groove is connected with the communication port of the mounting groove and is located on the inner side of the cleaning piece, the lower side of the collecting groove is provided with a communication port communicated with the inside of the shell, the communication port on the lower side of the collecting groove is provided with a one-way valve, and the one-way valve is used for blocking the solution in the shell from entering the collecting groove.
Preferably, the collecting assembly further comprises a movable pushing plate, the movable pushing plate is attached to the side wall of the collecting groove and slides, the movable pushing plate is connected with a connecting rod, a guide groove is further formed in the mounting groove, the connecting rod stretches into the guide groove, a limiting block is connected in the guide groove, a limiting groove is formed in the lower end of the movable frame, and when the movable frame moves to the position where the limiting groove is opposite to the limiting groove, the limiting block is inserted into the limiting groove and drives the movable pushing plate to synchronously move along with the movable frame.
The urea synthesis process includes the following steps:
S1, preparing raw materials, wherein a raw material supply unit provided by the invention provides liquid ammonia and carbon dioxide required by urea production;
s2, reacting, namely introducing the synthetic raw materials into the horizontal reactor provided by the invention to perform a first-step reaction, and introducing the liquid component and the gas component generated by the horizontal reactor into the synthetic tower provided by the invention to perform a second-step reaction;
S3, separating, namely introducing liquid components discharged from the synthesis tower into the liquid-phase circulation unit provided by the invention to purify the liquid components, introducing gas components discharged from the synthesis tower into the gas-phase circulation unit provided by the invention, and recycling ammonia and carbon dioxide in the gas-phase components;
S4, refining, namely introducing the product purified by the liquid-phase circulation unit into an evaporation granulation system, and obtaining the final product urea.
The beneficial effects of the invention are as follows:
(1) The invention provides a urea synthesis system, which is provided with a horizontal reactor and a synthesis tower according to the temperature condition of urea production reaction, so as to promote the generation proportion of required products, collect and utilize ammonia and carbon dioxide through a gas-phase circulation system, separate methyl ammonium liquid in urea through a liquid-phase circulation system and increase the purity of urea in liquid-phase components.
(2) The horizontal reactor provided by the invention is provided with the heat exchange mechanism, the heat exchange mechanism can timely discharge heat in the horizontal reactor, the production of intermediate product methyl ammonium is promoted, and meanwhile, each radiating pipe in the heat exchange mechanism is independently detached and connected with the shell, so that when the horizontal reactor works and suffers from leakage or faults of a single radiating pipe, workers can timely withdraw damaged radiating pipes, and the original mounting groove is blocked, so that the normal work of the horizontal reactor is prevented from being influenced.
Drawings
FIG. 1 is a schematic diagram of the overall structure of a urea synthesis system according to the invention.
FIG. 2 is a schematic perspective view of a horizontal reactor according to the present invention.
Fig. 3 is a schematic view showing a structure of the radiating pipe connected to the end cover plate in normal operation of the present invention.
Fig. 4 is a schematic view of the structure of the radiating pipe of the present invention with the opposite end cover plate removed.
Fig. 5 is a schematic view of the structure of the radiating pipe of the present invention after the opposite end cover plate is removed.
Fig. 6 is a schematic perspective view of a closure assembly according to the present invention.
FIG. 7 is a schematic view of the cleaning member of the present invention.
FIG. 8 is a schematic diagram of the structure of the movable push plate connected with the cleaning member through the connecting rod and the limiting block.
Reference numerals:
1. A horizontal reactor; 11. an ammonia pump; 12. an end cover plate; 13. a mounting groove; 14. a guide groove; 2. a synthesis tower; 3. a carbon dioxide stripping column; 31. a carbon dioxide compressor; 4. a medium pressure flash drum; 5. a medium pressure methylamine separator; 6. a medium pressure methylamine condenser; 7. medium pressure methyl ammonium liquid level tank; 71. a medium pressure recovery device; 8. a medium pressure rectifying tower; 9. a low pressure rectifying column; 91. a low pressure recovery device; 92. an evaporation granulation system; 100. a heat radiating pipe; 110. a moving frame; 111. a cleaning plate; 112. a limit groove; 120. a fixing member; 121. a second elastic member; 130. a blocking member; 131. a first elastic member; 140. a movable push plate; 141. a connecting rod; 142. a limiting block; 150. a collection tank.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
As shown in fig. 1, the urea synthesis system of the invention comprises a raw material supply unit, a reaction unit, a gas-phase circulation unit and a liquid-phase circulation unit, wherein the raw material supply unit is used for supplying liquid ammonia and carbon dioxide required by urea synthesis, the raw material supply unit comprises a carbon dioxide compressor 31 and an ammonia pump 11, the carbon dioxide compressor 31 is connected with a carbon dioxide stripping tower 3, the gas outlet end of the carbon dioxide stripping tower 3 is connected with reaction equipment, the ammonia pump 11 is connected with the reaction equipment through a liquid ammonia preheater, the liquid ammonia pump 11 inputs the liquid ammonia pump 11 into the liquid ammonia preheater, the liquid ammonia preheater heats the liquid ammonia, the heated liquid ammonia is led into the reaction equipment, the liquid ammonia preheater heats the liquid ammonia to 50-60 ℃, the reaction unit provides proper reaction equipment according to the reaction condition of raw materials, the gas-phase circulation unit is used for recycling ammonia and carbon dioxide generated in the production process, the production efficiency of urea is improved, and the liquid-phase circulation unit is used for repeatedly purifying liquid phase reactants generated by the reaction equipment and obtaining final product urea.
In order to improve the efficiency of urea production, the urea synthesis system provided by the invention is provided with different reaction devices corresponding to two-step reactions of urea synthesis, the reaction devices comprise a horizontal reactor 1 and a synthesis tower 2, and the first step is that liquid methylamine is generated from liquid ammonia and carbon dioxide: the reaction of 2NH3+CO2.about.NH2COONH4 is mainly carried out in the horizontal reactor 1, the ammonia pump 11 and the liquid ammonia preheater are used for conveying liquid ammonia into the horizontal reactor 1, the carbon dioxide compressor 31 and the carbon dioxide stripping tower 3 are used for conveying carbon dioxide into the horizontal reactor 1, the heat exchange mechanisms are arranged in the horizontal reactor 1 in a detachable way and can be arranged at two ends of the horizontal reactor 1, the heat exchange mechanisms can effectively improve the heat exchange efficiency, the heat generated by liquid ammonia and liquid methyl ammonium generated by carbon dioxide is timely discharged, the synthesis efficiency of intermediate product liquid methyl ammonium is further improved, two groups of heat exchange mechanisms are respectively arranged at two ends of the horizontal reactor 1 for realizing concentrated recovery of the heat, one group of heat exchange mechanisms is used for introducing desalted water, the desalted water is used for recycling and absorbing the reaction heat in the heat exchange mechanisms to generate low-pressure steam, and the generated low-pressure steam can be used for a low-pressure system and an evaporation system, so that the recovery and reutilization of waste heat are realized, and the requirements of energy conservation and environmental protection are met.
And then, conveying the product in the first step of reaction into the synthesis tower 2 for a second step of reaction, wherein the first step of reaction is reversible reaction, the components conveyed from the horizontal reactor 1 to the synthesis tower 2 comprise liquid phase components and gas phase components, the liquid phase components comprise ammonia and carbon dioxide, the ammonia and the carbon dioxide are partially converted into liquid ammonia and release heat in the synthesis tower 2, the released heat can provide heat for the reaction of converting the ammonia into the urea so as to promote the generation of the urea, the excessive ammonia and carbon dioxide are discharged from the gas outlet end of the synthesis tower 2 and enter a gas phase circulation unit, the liquid phase components react in the synthesis tower 2, the ammonia in the liquid phase components is largely converted into the urea, the liquid phase product after the second step of reaction reaches balance comprises the urea, the ammonia, the water and a small amount of ammonia and carbon dioxide dissolved in the liquid components, and the liquid component discharged from the synthesis unit Cheng Da is purified in the liquid phase circulation unit so as to obtain the final product urea.
The gas-phase circulation unit comprises a medium-pressure methylamine condenser 6 and a medium-pressure methylamine liquid level tank 7, ammonia and carbon dioxide entering the medium-pressure methylamine condenser 6 are dissolved with a solution of the medium-pressure methylamine condenser 6 under the condensation effect to form a methylamine liquid, the solution in the medium-pressure methylamine condenser 6 is a liquid containing ammonia and carbon dioxide with a certain solubility, the methylamine liquid is a solution containing carbon dioxide with higher concentration, the discharge end of the medium-pressure methylamine condenser 6 is connected with the feed end of the medium-pressure methylamine liquid level tank 7, the methylamine liquid in a liquid phase and a small amount of ammonia and carbon dioxide enter the medium-pressure methylamine liquid level tank 7 through the discharge end of the medium-pressure methylamine condenser 6, the medium-pressure methylamine liquid level tank 7 is used for storing the methylamine liquid, the methylamine liquid containing high-concentration ammonia and carbon dioxide is pressurized and introduced into the horizontal reactor 1 through a high-pressure methylamine pump for reaction, the collection and conversion utilization of the ammonia and the carbon dioxide are realized, the ammonia and the carbon dioxide discharged from the discharge end of the medium-pressure methylamine liquid tank 7 enters a medium-pressure device 71 for recycling the ammonia and the medium-pressure methylamine liquid level tank 71 for recycling the ammonia and the low-concentration methylamine liquid 7.
The liquid phase circulation unit comprises a carbon dioxide stripping tower 3, a medium pressure flash tank 4, a medium pressure methyl ammonium separator 5, a medium pressure rectifying tower 8 and a low pressure rectifying tower 9, wherein products discharged from the medium pressure flash tank 4 firstly enter the carbon dioxide stripping tower 3, the carbon dioxide stripping tower 3 promotes partial methyl ammonium in liquid components to be decomposed into ammonia and carbon dioxide under the action of carbon dioxide stripping, the ammonia and the carbon dioxide generated by decomposition enter the horizontal reactor 1 from the air outlet end of the carbon dioxide stripping tower 3 and undergo a first step reaction in the horizontal reactor 1, the rest urea, the methyl ammonium and water enter the medium pressure flash tank 4, the pressure in the medium pressure flash tank 4 is reduced, the methyl ammonium is promoted to be decomposed in the medium pressure flash tank 4 to generate ammonia and carbon dioxide, the ammonia and the carbon dioxide generated by the medium pressure flash tank 4 enter the medium pressure rectifying tower 8, the liquid components generated by the medium pressure flash tank 4 are flash liquid, the main components of the flash liquid are urea, water and methyl ammonium, the flash liquid enters another group of heat exchange mechanisms in the horizontal reactor 1 and absorbs heat in the horizontal reactor 1, the methyl ammonium in the flash liquid is promoted to be converted into ammonia and carbon dioxide, the flash liquid discharged from the heat exchange mechanisms of the horizontal reactor 1 and the ammonia and carbon dioxide generated by the decomposition of the methyl ammonium enter a medium-pressure methyl ammonium separator 5, the medium-pressure methyl ammonium separator 5 separates gas phase components from liquid phase components, the ammonia and the carbon dioxide in the gas phase enter a medium-pressure methyl ammonium condenser 6 of a gas-phase circulation unit through the gas outlet end of the medium-pressure methyl ammonium separator 5, the urea, the methyl ammonium and the water in the liquid phase enter a medium-pressure rectifying tower 8, the ammonia and the carbon dioxide generated by the decomposition of the medium-pressure flash tank 4 strip the entering the liquid phase components in the medium-pressure rectifying tower 8 so as to promote the separation of the ammonia and the carbon dioxide contained in the liquid phase components, ammonia and carbon dioxide generated by the medium pressure rectifying tower 8 also enter the medium pressure methyl ammonium condenser 6 of the gas phase circulation unit, a liquid product of the medium pressure rectifying tower 8 enters the low pressure rectifying tower 9 and continuously decomposes methyl ammonium in the liquid product, the low pressure rectifying tower 9 decomposes ammonia and carbon dioxide generated by the methyl ammonium to obtain a low pressure recovery device 91, the low pressure recovery system is used for collecting a small amount of ammonia and carbon dioxide discharged by the low pressure rectifying tower 9, the liquid product is urea and water, and the liquid product enters the evaporation granulating system 92 to finally generate urea.
As shown in fig. 2 to 8, the structure of the horizontal reactor 1 specifically includes a housing and heat exchange mechanisms, a space for raw material reaction is formed inside the housing, two groups of heat exchange mechanisms are respectively provided at two axial ends of the housing, the two groups of heat exchange mechanisms are respectively used for introducing desalted water and flash liquid, one group of heat exchange mechanisms includes a plurality of heat dissipating pipes 100, the heat dissipating pipes 100 are in a U-shaped tubular shape, end cover plates 12 are detachably mounted at two axial ends of the housing, a plurality of mounting grooves 13 are provided on the end cover plates 12, each heat dissipating pipe 100 corresponds to each mounting groove 13 one by one, plugging components are provided in each mounting groove 13, the heat dissipating pipes 100 are connected with the plugging components so as to face the inner side of the housing, the plugging components include plugging pieces 130, cleaning pieces and fixing pieces 120 which are sequentially provided from inside to outside, the two plugging pieces 130 are hinged with the mounting groove 13, the inner side end part of the mounting groove 13 is plugged when the two plugging pieces 130 are in butt joint, the cleaning piece is in sliding arrangement in the mounting groove 13 and is attached to the side wall of the mounting groove 13, the two plugging pieces 130 are connected with the cleaning piece through the first elastic piece 131, the first elastic piece 131 is of an elastic telescopic rod-shaped structure, one end of the first elastic piece 131 is hinged with the plugging piece 130, the other end of the first elastic piece 131 is hinged with the cleaning piece, any plugging piece 130 can be connected with the cleaning piece through the two first elastic pieces 131, the cleaning piece 111 is under the tensile force of the first elastic piece 131, and the tensile force of the first elastic piece 131 on the cleaning piece 111 is increased in the process that the cleaning piece 111 is away from the plugging piece 130;
the mounting 120 is frame-shaped mechanism, and mounting 120 is fixed with mounting 13, and the clearance piece is connected with mounting 120 through second elastic component 121, and second elastic component 121 is the telescopic shaft-like structure of elasticity equally, and the one end and the clearance piece of second elastic component 121 are fixed, and the other end and the mounting 120 of second elastic component 121 are fixed, and accessible a plurality of second elastic components 121 are connected between mounting 120 and the clearance piece, and the clearance piece receives the thrust effect of second elastic component 121, and the direction of the thrust that the clearance piece received is towards shutoff piece 130, and when the clearance piece was close to mounting 120, the thrust effect of the second elastic component 121 that the clearance piece received was increased.
The cleaning piece comprises a movable frame 110 and two cleaning plates 111 arranged in the movable frame 110, each side wall of the movable frame 110 is attached to the mounting groove 13 to slide, the two cleaning plates 111 are hinged to two opposite side walls of the movable frame 110 at the inner side of the movable frame 110, the cleaning plates 111 can be connected with the movable frame 110 through torsion springs, semicircular notches are formed at the end parts of the two cleaning plates 111 for butt joint, round holes for the heat dissipation tube 100 to pass through are formed after the two cleaning plates 111 are in butt joint, the two cleaning plates 111 are attached to the outer side wall of the heat dissipation tube 100, when the heat dissipation tube 100 works, the heat dissipation tube 100 penetrates through the mounting groove 13 and stretches into a shell, the end part of the heat dissipation tube 100 with an opening is positioned at the outer side of the end cover plate 12, the two openings of the heat exchange tube are used for connecting a liquid inlet pipeline and a liquid outlet pipeline, desalted water or flash evaporation liquid is led into the heat dissipation tube 100 from one opening of the heat dissipation tube 100 and flows out of the other opening after circulating through the heat dissipation tube 100, and heat in the shell is absorbed;
When the radiating pipe 100 works normally, the two plugging pieces 130 are opened relatively and are abutted against the outer wall of the radiating pipe 100 under the action of the elastic force of the first elastic piece 131, the two cleaning plates 111 are attached to the outer wall of the radiating pipe 100, the mounting groove 13 is formed at the cleaning plates 111 to be plugged, solution in the shell is prevented from flowing out of the mounting groove 13, when the radiating pipe 100 is abnormal, the radiating pipe 100 is pulled to move outwards, when the inner side end of the radiating pipe 100 is moved to be separated from the plugging pieces 130, the two plugging pieces 130 are abutted and closed under the action of the elastic force of the first elastic piece 131, the two plugging pieces 130 are abutted to be connected with the mounting groove 13, then the radiating pipe 100 is pulled continuously, the radiating pipe 100 is extruded to be separated from the cleaning pieces relatively, finally the radiating pipe 100 is pulled out of the mounting groove 13, and then the outer side opening of the mounting groove 13 can be plugged by using a cover plate.
When the heat pipe 100 is in the housing, the reaction solution is attached to the outer peripheral side thereof, and when the heat pipe 100 is drawn, a part of the solution enters the installation groove 13, and in order to collect the solution attached to the heat pipe 100 and the solution entering the installation groove 13, a collection assembly for collecting the solution is further provided in the installation groove 13.
The collecting assembly comprises a collecting tank 150 and a movable push plate 140, wherein the upper side of the collecting tank 150 is communicated with the mounting tank 13, a communication port between the collecting tank 150 and the mounting tank 13 is positioned at the front side of the cleaning piece, the lower side of the collecting tank 150 is communicated with the inside of the shell, a one-way valve is arranged at the communication port of the collecting tank 150, which is used for assisting the solution in the collecting tank 150 to be discharged into the shell, and preventing the solution in the shell from entering the collecting tank 150, the movable push plate 140 is used for being jointed with the collecting tank 150 to push the solution in the collecting tank 150 to quickly flow into the shell, the movable push plate 140 is jointed with the side wall of the collecting tank 150 to move, the movable push plate 140 is also connected with a connecting rod 141, a guide groove 14 is also arranged in the mounting tank 13, the connecting rod 141 stretches into the guide groove 14 and is connected with a limiting block 142 in the guide groove 14, the stopper 142 is elastically telescopic structure, the lower extreme of moving frame 110 is equipped with spacing groove 112, the stopper 142 upper end is the arcwall face, the cooling tube 100 breaks away from shutoff piece 130 to its end and clearance piece contact, and promote and move frame 110 and slide in mounting groove 13, when moving frame 110 and moving the spacing groove 112 of moving frame 110, stopper 142 stretches into, move frame 110 and connecting rod 141 relatively fixed through stopper 142, and then with movable push pedal 140 relatively fixed, after cooling tube 100 breaks away from with the clearance piece, the clearance piece is moved to the direction that is close to shutoff piece 130 under the tensile force of first elastic component 131 and the thrust action of second elastic component 121, and promote movable push pedal 140 and move in collecting vat 150, the solution in the extrusion collecting vat 150 gets into the casing.
According to the horizontal reactor 1 provided by the invention, when leakage or failure occurs in a single radiating pipe 100, the damaged radiating pipe 100 is pulled out for maintenance, the original mounting groove 13 is blocked, the influence on the work of the horizontal reactor 1 is avoided, when the whole horizontal reactor 1 is maintained, the radiating pipe 100 after maintenance is inserted into the corresponding mounting groove 13, and the limiting block 142 is separated from the movable frame 110 before the radiating pipe 100 is mounted.
The specific steps of the urea synthesis method provided by the invention are as follows:
s1, preparing raw materials, and providing liquid ammonia and carbon dioxide required by urea production by a raw material supply unit;
s2, reacting, namely introducing the synthetic raw materials into the horizontal reactor 1 to perform a first-step reaction, and introducing the liquid component and the gas component generated by the horizontal reactor 1 into the synthesis tower 2 to perform a second-step reaction;
S3, separating, namely introducing the liquid component discharged from the synthesis tower 2 into a liquid phase circulation unit to purify the liquid component, introducing the gas component discharged from the synthesis tower into a gas phase circulation unit, and recycling ammonia and carbon dioxide in the gas phase component;
s4, refining, namely introducing the product purified by the liquid-phase circulation unit into an evaporation and granulation system 92, and obtaining the final product urea.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present 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" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.
Claims (8)
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| CN115175898A (en) * | 2020-02-25 | 2022-10-11 | 卡萨乐有限公司 | Process and plant for the synthesis of urea |
| CN218853480U (en) * | 2022-12-30 | 2023-04-14 | 呼伦贝尔金新化工有限公司 | Urea production system for comprehensively utilizing waste heat of steam condensate |
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| CN103570588A (en) * | 2013-08-30 | 2014-02-12 | 北京丰汉工程技术有限公司 | Urea synthesis device and urea synthesis method |
| EA201890452A1 (en) * | 2015-09-08 | 2018-08-31 | Тойо Инджиниринг Корпорейшн | METHOD OF OBTAINING UREA AND INSTALLATION FOR OBTAINING UREA |
| CN117282355A (en) * | 2023-11-22 | 2023-12-26 | 丁泽华 | Horizontal urea synthesis reactor and urea synthesis high-pressure ring equipment and process |
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| CN218853480U (en) * | 2022-12-30 | 2023-04-14 | 呼伦贝尔金新化工有限公司 | Urea production system for comprehensively utilizing waste heat of steam condensate |
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Effective date of registration: 20251216 Address after: 271509 Eastping County, Taian City, Shandong Province, Chenliuzewei Village, Pengji Street, Eastping E-commerce Industrial Park, Room 1002 Patentee after: Shandong runyin Fertilizer Technology Co.,Ltd. Country or region after: China Address before: 271500 East Ping Economic Development Zone, Dongping County, Tai'an City, Shandong Province, west side of National Highway 105 (Pengji Street) Patentee before: SHANDONG FUFU NEW MATERIAL TECHNOLOGY CO.,LTD. Country or region before: China |