• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Process for concentrating a urea solution passing as a film along the inside of the tubes (2) of a vertical tube bundle the heat required being substantially generated by condensation of a gas mixture in a area provided around the bundle of tubes, the gas mixture being supplied to the area near one end of the tube bundle (2) and the urea solution to the other end of the tube bundle (2), and being passed substantially upwards through the heating area and it is ensured that the gas mixtureor condensate cannot flow back. Installation for carrying out the process wherein the heating area is divided into compartment by means of horizontal baffles (3) allowing an upwardly directed flow of the gas mixture and the condensate.
    公开号:SU1736335A3
    申请号:SU874203645
    申请日:1987-11-02
    公开日:1992-05-23
    发明作者:Йонкерс Кес；Христиан Буркс Хенк
    申请人:Стамикарбон Б.В.(Лайсенсинг Сабсидиари Ов Дмс) (Фирма)；
    IPC主号:
    专利说明:

    317
    This invention relates to a process for the production of urea from ammonia and carbon dioxide, in particular to a method for producing a concentrated solution of urea and to an apparatus for carrying out the method.
    The aim of the invention is to reduce the heat exchange surface in heat exchange equipment at the stage of evaporation of water from the urea solution.
    The drawing shows schematically a part of the heating zone of the first stage of evaporation of the solution, with partitions of the tube of the tubular system, section
    The outer casing 1 enters the heating zone, the tubular tube 2, the baffles 3, the central hole 4, the holes 5 near the periphery, the flanges 6 protruding downward into the gaskets 7. The liquid phase flows in the direction indicated by arrows 8, and the gas phase moves in the direction indicated by the arrows 9.
    The concentration-oriented urea solution is fed to the plates of the fluid flow distribution to form a film moving downward within the tubes 2.
    In the device in each compartment, the reaction between the gas mixture (ammonia, carbon dioxide and water vapor) and the aqueous solution (dilute carbamate solution) is carried out.
    As a result, a significant amount of heat is released, after which the liquid and gaseous phases are separated and each phase is transferred to the next compartment separately.
    The gas mixture is fed to the lower part of the apparatus and it flows through the liquid phase up to the partition. At this point, the gas mixture is blocked and a gas cushion is formed. The partition contains several openings, as a result of which the gas mixture passes through the partition through these openings. However, the time required for the gas mixture to pass through these openings is longer than the time required to reach the partition with a gas mixture. When the gas mixture accumulates directly under the partition wall, a gas cushion is formed. At the same time, the number of openings without a rim, protruding downwards (pos. 9), is equal to the number of pipes and the placement of these openings is identical to the placement;
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    nor the passage of the gas mixture through these openings along the outside of the pipes. This first group of holes differs from the second group of holes, in which the rim protrudes downward (pos. 8), in order to pass the condensate and / or carbamate solution through them. Since each tube of tube bundle passes through the openings of the first group, their placement must match each other. If necessary, some holes from the first group can be plugged.
    Consequently, the number of holes of the first group must be at least equal to the number of pipes of the pipe bundle. In particular, if there are ten baffles and each baffle contains one hole, then all of these ten holes must be placed in the same position in order to ensure that one tube passes through them from top to bottom. In this case, one pipe corresponds to ten holes. However, nine of these holes or less can be plugged. In this case, one hole (when 9 are plugged) will correspond to one pipe. Therefore, the number of holes must at least correspond to the number of pipes.
    Example. The figures given refer to a plant with a capacity of 1500 tons / day. Quantities are expressed in kilograms per hour.
    35,414 kg of ammonia and 45,863 kg of carbon dioxide are supplied to the high pressure sector of the installation. Pressure in the high pressure sector, which includes the synthesis zone, the first decomposition stage, the condensation zone and the scrubber zone for inert gases, is 140 kg / cm2. The pressure in the second stage of decomposition and in the heating zone of the first stage of evaporation is 17.7 kg / cm2. The pressure in the third decomposition stage is 3.9 kg / cm2. The gas mixture from the second decomposition stage, containing 14,139 kg of carbon dioxide, 8711 kg of ammonia and 3301 kg of water, is directed to the first stage of evaporation in the lower part of the heating zone, surrounding the tubular system.
    The heating zone around the tubes is divided into ten sections using partitions. These partitions are provided with openings provided alternately in the center or on the periphery, with
    around these holes are the sides protruding downwards. These openings serve to flow from the bottom up to the flow of the liquid phase through the sections. The gas mixture containing ammonia, carbon dioxide and water vapor passes successively through the upper sections through the gaps between the tubes and partitions. In addition, between the tubes in successive partitions, additional holes for the gas flow are provided in the decreasing number.
    The temperature of such a gas mixture is 158.6 ° C, its dew point is 143.4 ° C. Due to the heat exchange between this mixture and 86623 kg of urea solution flowing downward in the form of a film through tubes, the temperature of which is and which contain 63525 kg of urea, 210 kg of biuret, 28 kg of carbon dioxide, 377 kg of ammonia and water (the rest) This gas mixture is cooled and condensed. The condensation and absorption of the gas mixture is continued using 20944 kg of carbamate solution leaving the third decomposition stage, containing 4294 kg of carbon dioxide, 7400 kg of ammonia, 9229 kg of water and 21 kg of urea, which is then sent to the third section of the heating zone at 47 P. 47079 kg of carbamate solution with (temperature 93, containing 18427 kg of carbon dioxide, 16102 kg of ammonia, 12529 kg of water and 21 kg of urea, is withdrawn from the upper section of the heating zone. 45 kg of gas a mixture that still contains 6.3 kg of carbon dioxide, 9.1 kg am iaka, 0.8 kg water vapor and inert gas (the rest).
    From the bottom of the tubular system, 67833 mg of a concentrated urea solution at 122.5 ° C was withdrawn. This solution contains 63144 kg of urea, 264 kg of Puret, 0.02 kg of carbon dioxide, 4.7 kg of ammonia and 4420 kg of water.
    Thus, the evaporated urea solution in the form of a film is passed from top to bottom along the inner surface of the tubes of the tubular system, and the condensing gas stream and the aqueous solution of carbamate are directed into the annular space at different points along the height of the apparatus.
    In the implementation of the proposed method, the heat required for the evaporation of water is supplied in the form of heat.
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    formed during the carbamate formation reaction from ammonia and carbon dioxide in the presence of water. However, in the case when the reagents in the heat exchanger casing, i.e. a gas mixture containing ammonia, carbon dioxide and water vapor, as well as a solution containing water, for example, a dilute carbamate solution, react in the descending flow in the casing, as is the case in the known method, it is impossible to ensure good wetting of the outer surface of the heat exchanger tubes, as a result, it is impossible to provide constant heat generation and heat exchange between the urea solution to be concentrated and the carbamate solution forming on the surface of the tubes in the heat exchanger casing, ts irregular and non-optimal in its parameters.
    This problem can be overcome using the invention by passing the urea solution to be concentrated in the form of a downward flow through the heat exchanger tubes into a gas mixture containing ammonia, carbon dioxide and water vapor, and the solution containing water as an upward flow through the casing, providing this is the impossibility of forming a reverse flow of the reaction mixture in the casing.
    The impossibility of forming a reverse flow is ensured by means of a gas cushion in each of the compartments and by separately passing the liquid phase and the gas phase from one compartment to the next as an upstream flow. Due to the presence of the rims 6, which are located in the downward direction in the upper part of the compartment, a gas cushion is formed above the liquid (position 7). The gas mixture is passed into the next compartment through the holes 9 separately from the liquid, which is passed through the holes 8.
    For the production of urea in the amount of 1500 tons / day, the heat exchange surface in accordance with the known method should be 1,487 m2. However, if the concentration step is carried out according to the invention, passing the urea solution in the form of an upward flow through the heat exchanger tubes, and generating the heat-gas mixture together with the aqueous solution in the form of a downward flow, then to achieve the same
    My solution concentration for the reasons noted above requires a heat exchange surface area of 3187 m2.
    Thus, carrying out the process using the proposed apparatus in the first stage of evaporation ensures good wetting of the outer surface of the tubes, which improves heat transfer and reduces the required heat exchange surface.
    权利要求:
    Claims (5)
    [1]
    1. A method of concentrating a urea solution by evaporation of the water contained therein by passing the urea solution in the form of a film along the inner surface of the tubes of the vertical tubular system of an evaporator while obtaining the amount of heat required for evaporation due to condensation in the heating zone of a gas mixture containing ammonia, carbon dioxide and water vapors, which are fed in countercurrent to the urea solution in the annular space near one of the ends of the tubes of the tubular system when the urea solution is fed from the other About the end of the tubes and supplying the carbamate aqueous solution to the tubular space at a point located between the urea solution injection site in the tubular system tubes and the gas mixture entering the tubular space of the apparatus, characterized in that, in order to reduce the metal intensity of the equipment while reducing the heat exchange surface, condensing the gas mixture is fed to the lower part of the heating zone, divided by horizontal perforated partitions into a number of sections,
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    one above the other, with the gas stream and the condensate being formed being directed to the upstream sections through different openings in the partition, which prevents the gas mixture or condensate from returning to the bottom section.
    [2]
    2. A device for concentrating a urea solution containing a vertical heat and mass transfer apparatus comprising a heating chamber, vertical heat exchange tubes attached to the upper and lower tube sheets and placed in the heating chamber, and a fitting for supplying the urea solution, in order to reduce the metal intensity of the equipment , the apparatus is provided with means for forming a film in the pipes and horizontal partitions placed one above the other in the heating chamber with the formation of sections, supply fittings and removal of the gas mixture and condensate, while the main and additional openings are made in the partitions, and the fitting for supplying the urea solution is located above the upper tube sheet.
    [3]
    3. The device according to claim 2, which is tlicit by the fact that the heat exchange tubes are placed in the main openings of the partitions with a gap.
    [4]
    4. Device popp.
    [5]
    5. Device according to p.2 - 4, o t - Characterized by the fact that additional holes are made in the partitions alternately in the center and on the periphery.
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    同族专利:
    公开号 | 公开日
    NZ222369A|1990-06-26|
    ZA878213B|1988-04-28|
    HUT44949A|1988-05-30|
    OA08770A|1989-03-31|
    BG60206B2|1993-12-30|
    NO874558L|1988-05-04|
    CN1022321C|1993-10-06|
    NO874558D0|1987-11-02|
    IL84340D0|1988-04-29|
    JPS63126858A|1988-05-30|
    TNSN87125A1|1990-01-01|
    AU604069B2|1990-12-06|
    CA1333912C|1995-01-10|
    BR8705824A|1988-06-28|
    AR245383A1|1994-01-31|
    IN170336B|1992-03-14|
    EG18504A|1993-04-30|
    PL268572A1|1988-09-01|
    NL8602769A|1988-06-01|
    US4866207A|1989-09-12|
    FI874808A0|1987-11-02|
    MX168831B|1993-06-10|
    TR24027A|1991-02-04|
    ZW19987A1|1988-02-03|
    AU8058287A|1988-05-05|
    EP0266839A1|1988-05-11|
    FI874808A|1988-05-04|
    PT86068A|1988-12-15|
    CN87107625A|1988-05-11|
    DD262806A5|1988-12-14|
    MA21099A1|1988-07-01|
    KR880006176A|1988-07-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE908028C|1948-11-03|1954-04-01|Hoechst Ag|Process and column for material turnover and heat exchanger|
    US2944966A|1954-02-19|1960-07-12|Allen G Eickmeyer|Method for separation of fluid mixtures|
    FR1111540A|1954-07-19|1956-03-01|heat exchanger allowing the practical use of the dilution energy of the concentrated solutions|
    FR1255949A|1959-11-12|1961-03-17|Multiple effect molecular evaporative distillation process and devices|
    US3137725A|1960-02-11|1964-06-16|Chemical Construction Corp|Heat recovery in urea synthesis process|
    US2998060A|1960-08-03|1961-08-29|Albert W Eckstrom|High temperature method and evaporator for concentrating solutions|
    SU144842A1|1960-10-25|1961-11-30|Б.Г. Мельников|Method of removing ammonia and carbon dioxide from urea synthesis products|
    NL6414630A|1964-12-16|1966-06-17|
    US4341640A|1976-09-27|1982-07-27|Standard Oil Company|Urea hydrolysis|
    US4231951A|1978-02-08|1980-11-04|Minnesota Mining And Manufacturing Company|Complex salt photoinitiator|
    JPS5715832B2|1978-11-30|1982-04-01|
    JPS5826909B2|1979-09-14|1983-06-06|Toyo Enjiniaringu Kk|
    JPS6116384B2|1980-09-12|1986-04-30|Mitsui Toatsu Kagaku Kk|
    IT1163795B|1983-07-18|1987-04-08|Montedison Spa|APPARATUS FOR THE STRIPPING OF AMMONIA FROM SOLUTIONS COMING FROM THE SYNTHESIS OF UREA|
    NL8303888A|1983-11-13|1985-06-03|Unie Van Kunstmestfab Bv|METHOD FOR THE PREPARATION OF UREA.|
    DE3565532D1|1984-05-19|1988-11-17|Ammonia Casale Sa|Process for the preparation of urea|
    JPH06110547A|1992-09-29|1994-04-22|Toshiba Corp|Sequence result data collector|CH679485A5|1989-12-29|1992-02-28|Ammonia Casale Sa|
    DE4034074A1|1990-10-26|1992-04-30|Huels Chemische Werke Ag|METHOD FOR PRODUCING ALKYL GLYCOSIDES AND ALKYLOLIGOGLYCOSIDES|
    DE19961040A1|1999-12-16|2001-06-21|Basf Ag|Thermoplastic molding compounds with improved processing behavior based on polyarylene ether sulfones and polyamides|
    EP2153880A1|2008-07-31|2010-02-17|Urea Casale S.A.|Process and plant for the production of a urea solution for use in SCR process for reduction of Nox|
    EP3190101B1|2012-05-03|2019-09-25|Stamicarbon B.V.|Method and apparatus for the production of urea from ammonia and carbon dioxide|
    EP3452212B1|2016-05-03|2020-02-12|Stamicarbon B.V.|Urea production with controlled biuret|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    NL8602769A|NL8602769A|1986-11-03|1986-11-03|METHOD FOR CONCENTRATING A UREA SOLUTION AND APPARATUS FOR CARRYING OUT THE METHOD|LV930298A| LV5230A3|1986-11-03|1993-05-06|Influence of the Urinelian Concentration and its Focus on Realization|
    LTRP723A| LT2204B|1986-11-03|1993-06-30|CARBAMIDE SOLUTION CONCENTRATION BUDGET AND ITS IMPLEMENTATION DEVICE|
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