Method and device for condensing carbamate (versions)

FIELD: chemistry.

SUBSTANCE: invention relates to a method of condensing carbamate through condensation of gaseous phase of carbon dioxide and ammonia into a liquid phase, which is carbamate in aqueous solution and optionally a solution which contains urea and non-reacting substances and liquid ammonia, in a submerged-type condenser, containing a given number of heat-exchange pipes in a bundle, meant for condensing carbamate, into each of which gaseous and liquid phases are fed simultaneously and independently from each other. The invention also relates to a submerged-type device for condensing carbamate.

EFFECT: increased efficiency and output of the method of condensing carbamate in the proposed device.

14 cl, 4 dwg

 

The present invention relates to a method of condensation of carbamate in the apparatus of the so-called flooded type (submerged coil) at the facility for artificial urea from gaseous carbon dioxide and liquid ammonia. The invention relates also to the apparatus for condensation of carbamate proposed in the invention method.

Upon receipt of urea source reagents, in particular carbon dioxide and ammonia, served partially condensed in the form of carbamate in the reactor for the synthesis of urea, which is essentially the final condensation of carbamate, which is the intermediate product of the synthesis. In the reactor due to a chemical balance that characterizes what is happening in it the conversion process, only a portion of the carbamate is converted into urea.

The remaining part is not transformed into urea carbamate together with unreacted ammonia exits the reactor and at least partially out of it after desorption, for example, CO2again get well-known methods of gaseous ammonia and carbon dioxide.

To obtain molten carbamate, which is then recycled to the reactor for the synthesis of urea, ammonia gas and carbon dioxide must at least partially condense.

As is known, the device for producing urea is not bhodemon to condense in the carbamate portion of the raw materials and intermediate products, not turned into a urea synthesis reactor and of which, after selection from the reactor to receive the gaseous ammonia and carbon dioxide, which is then again returned to the reactor.

To do this, in EP-A-1036787 was proposed condensing apparatus of the so-called flooded type with a cylindrical body and located therein by a bunch of straight tubes, which are cooled with a suitable thermal fluid with low temperature (refrigerant).

In the tube bundle, the tube filled with liquid (submerged in the liquid) condensation occurs and the interaction of ammonia and carbon dioxide with the formation of the carbamate.

This condensing unit (hereinafter called simply a capacitor) for all its advantages, however, one detail below, a significant shortcoming.

As it was found, in fact, this capacitor does not meet in full the requirements of the standards, and the conversion of carbamate passing through the pipe upward gaseous compounds occurs only in a small part of the entire tube bundle. The main (most) part of the pipe is filled with liquid phase and partly used for recycling part of the condensed gaseous compounds from the upper part of the tube bundle in its lower part. In other words, in such a capacitor is gazoobraznye connections pass through a specific path through a very small number of tubes of the tube bundle in accordance with the actual concentration of heterogeneous agents.

If certain dimensions of the tube bundle, the output capacitor is determined only by the number of pipes in which the process of condensation (i.e. the number of pipes through which gaseous compounds), and therefore the availability in the designated condensing tube bundle of a large number of pipes filled only in the liquid phase, substantially reduces condensation output capacitor. On the efficiency of the condenser, in addition, has an adverse effect occurring in it natural circulation formed in the liquid phase.

The present invention was used to develop this method of condensation of carbamate in the apparatus of the so-called flooded type, efficiency and condensing the output of which far exceeded the efficiency and condensing the output of the currently known methods of condensation of carbamate.

This problem is solved according to the invention with its proposed method of condensation of carbamate by condensation of the gaseous phase carbon dioxide and ammonia in the liquid phase, representing the carbamate in aqueous solution and optionally a solution containing urea and unreacted substances and liquid ammonia in the condenser apparatus of the so-called flooded type, containing the beam taproom is the R pipes with a certain number of pipes, intended for condensation of carbamate, characterized in that each intended for condensation of carbamate pipe gaseous and liquid phase serves simultaneously and independently from each other.

Proposed in the invention method enables efficient use of all designed for condensing tubes of the tube bundle to become carbamate gaseous compounds. In fact, separate and independent supply of gaseous phase and liquid phase in each intended for condensation of carbamate pipe provides a uniform and homogeneous distribution of gaseous compounds around the beam pipe.

In this regard, it should be noted that the condensation and interaction of gaseous compounds occur within each intended for condensation pipe is essentially under the same operating conditions, which significantly increases the coefficient of heat transfer and condensation increases the output capacitor.

Due to the condensation of gaseous compounds in all designated tubes of the tube bundle offer in the invention method can improve the efficiency and condensing the output capacitor, in which the condensation of carbamate is proposed in the invention method.

In the private embodiment, the gaseous phase is served in the centre is built in condenser apparatus for the tube bundle gas distribution chamber, collect gaseous phase in the gas distribution chamber and serves gaseous phase in intended for condensation of carbamate pipe through a set of connecting pipes that run from the gas distribution chamber to the pipe intended for condensation of carbamate.

In another private version of the gaseous phase served in located in the condenser apparatus for the tube bundle gas distribution chamber, collecting the gaseous phase in the gas distribution chamber and serves it in above the second gas distribution chamber, collecting the gaseous phase in the second gas distribution chamber and serves gaseous phase in intended for condensation of carbamate pipe through a set of connecting pipes, which pass from the second gas distribution chamber to the pipe intended for condensation of carbamate.

This in intended for condensation of carbamate pipe liquid phase is fed through the annular gaps between the pipes intended for condensation of carbamate, and the connecting pipes.

The invention also features apparatus for condensation of carbamate flooded type, in which the gaseous phase carbon dioxide and ammonia is condensed into the liquid phase, representing the carbamate in aqueous solution and not necessarily the solution, the soda is containing urea and unreacted substances and liquid ammonia, and which contains a bundle of heat exchange tubes with a certain number of tubes, inside which there is a condensation of carbamate, and the gas distribution chamber, which is collected is fed into the apparatus gaseous phase, characterized in that it has lots of connecting pipes that go from the gas distribution chamber and go into the pipe intended for condensation of carbamate, and thus directly connect the gas distribution chamber with these pipes.

Private options exercise of the connecting pipes have a free upper end which enters a short distance into the lower end of pipe intended for condensation of carbamate. The diameter of the upper end of the connecting pipe is less than the diameter of the lower end of the pipe intended for condensation of carbamate, which between these pipes a gap for the passage of the liquid phase inside the pipe.

The apparatus may have at least one reflective wall disposed between the gas chamber and tube bundle and at least under one pipe intended for circulation of the liquid phase.

The invention also features apparatus for condensation of carbamate flooded type, in which the gaseous phase carbon dioxide and ammonia is condensed into the liquid phase, representing the Yu a carbamate in aqueous solution and not necessarily the solution, contains urea and unreacted substances and liquid ammonia, and which contains a bundle of heat exchange tubes with a certain number of tubes, inside which there is a condensation of carbamate, and located under the tube bundle gas distribution chamber, which is collected is fed into the apparatus gaseous phase, characterized in that it has a second gas distribution chamber located between the first gas chamber and the tube bundle, which meets supplied to it from the first gas chamber in gaseous phase, and many of the connecting pipes that go from the second gas distribution chamber and go into the pipe intended for condensation of carbamate, and thus directly connect the second gas distribution chamber with these pipes.

In private variants of implementation of the second gas distribution chamber is divided into adjacent sectors, which are separated from each other by a narrow gap, forming a channel for passage between adjacent sectors of the liquid phase. While the device has reflectors gaseous phase, functionally associated with channels for the passage of the liquid phase between adjacent sectors. Adjacent to each side wall adjacent sectors have different height and shape, and reflectors gaseous phase is executed in the form from the bent lower free ends of the longer side walls, that bottom overlapping the shorter wall.

The apparatus may have at least one reflective wall located between the second gas chamber and tube bundle and at least under one pipe intended for circulation of the liquid phase.

Sector preferably connected to each other by pipes, which from one sector to another passes the gaseous phase.

Other distinctive features and advantages of the present invention is described in more detail below, the example does not limit the invention in one of its possible variants of implementation with reference to the accompanying description of the drawings on which is shown:

figure 1 - schematic representation in cross section of the condenser is intended for carrying out the invention method,

figure 2 - schematic representation in cross section of part of the condenser shown in figure 1,

figure 3 - schematic representation in cross section made according to another variant of the condenser is intended for carrying out the invention method, and

figure 4 is a schematic depiction in cross section of part of the capacitor shown in figure 3.

Shown in figures 1 and 2 condenser indicated in the Assembly position 1, is designed to condense the tion of carbamate proposed in the invention method and has a cylindrical housing 2, closed from opposite ends of the upper and lower ends 3 and 4 respectively.

In the housing 2 of the capacitor is the beam 5 tubes of a certain size, consisting of a certain number of straight pipes 6 a certain length and a certain diameter, which are mounted to upper and lower tube grids 7 and 8, respectively. Tube 7, and 8 separate the middle part of the housing 2 from the bottoms 3 and 4 and together with the housing 2 split capacitor 1 on average, the upper and lower parts 9, 10 and 11, respectively.

The upper and lower parts 10 and 11 of the capacitor are connected to each other by straight tubes 6 of the tube bundle 5. All tubes 6 of the tube bundle is divided into two groups, one of which includes a pipe 6', inside which there is a condensation of carbamate, and the other includes pipe 6", intended for recycling part of the condensed gaseous compounds from the upper part 10 of the capacitor 1 in its lower part 11.

It should be noted that the tubes 6 of the tube bundle 5 outside cooled appropriate coolant, such as water, which is fed to the condenser and is removed from it through the corresponding hole and the usual well known and therefore not shown in the drawings, the connecting device.

In the upper part 10 of the capacitor is first hole 12 for a gas outlet in the top plate 3, and dt the e hole 13, made in the side wall of the bottom.

At the top the bottom 10 next to the second hole 13 are overflow device, schematically shown in the drawings in the form of partitions 14.

In the lower part 11 of the capacitor is first hole 15, through which passes a fixed therein by a pipe 16, intended for supply to the condenser condensed gases, and the second hole 19, through which the capacitor serves the liquid phase, as discussed more fully described below.

The free end 17 of the first pipe 16 is located inside the distribution chamber 18, which as usual is mounted inside the lower part 11 of the capacitor. Distributing chamber 18 has a perforated wall 18a, located next to the lower tube sheet 8.

Proposed in the invention, the capacitor 1 includes, as shown in figure 2, which shows a marked in figure 1 by the letter And the part of the condenser, many of the connecting pipe 21, which emerge from the gas distribution chamber 18 and come inside intended for condensing gas pipe 6', in which due to the presence of connecting pipes gas to flow directly from the distribution chamber. It should be noted that the figure 1 image, where for simplicity shown only schematically separate connecting pipe 21, does not give full representation or amount, and location of such pipes unlike shown in figure 2 images, where these pipes are shown in more detail.

A connecting pipe 21, in particular, fixed in the holes 20 of the perforated wall 18a of the distribution chamber in such a way that their free upper ends 21A includes the inside of the pipe 6' near their lower ends 6A.

The diameter of the upper end 21A of the connecting pipe 21 should be less than the diameter of the lower end designed for condensing gas pipe 6' to between the connecting pipe 21 and the pipe 6' remained a gap 22 to pass into the pipe 6' of the liquid phase.

Below explains how it is shown in figure 1 and 2 condenser 1 is the condensation of carbamate proposed in the invention method. Figures 1 and 2 arrows Fgand F1the indicated direction of flow of the gaseous and liquid phase in the condenser 1, and the arrows Fg+Flthe indicated direction of flow of the mixture of gaseous and liquid phases in intended for condensing tubes 6'. In addition, the arrow Fcthe indicated direction of flow of the coolant at the inlet and at the outlet of the condenser 1.

As shown in figure 1, during normal operation, almost all of the internal space of the condenser 1 is filled in the liquid phase, which is an aqueous solution of carbamate, ammonia and optionally urea, and the gaseous phase composed of gaseous compounds, the content is asih ammonia, carbon dioxide and, as a rule, water vapor.

Gaseous compounds in the form of vapor fed into the condenser is located behind the synthesis reactor (not shown) of desorber (not shown), in which the decomposition of the carbamate and distillation of ammonia and carbon dioxide from the fed to him from the reactor for the synthesis of urea solution. Gaseous compounds, which are served in the capacitor above the first pipe 16, is collected in the bottom 11 of the capacitor of the distribution chamber 18.

At the same time in the lower part 11 of the condenser 1 through the second hole 19 of section regeneration urea (not shown) serves carbamate in aqueous solution and not necessarily from the synthesis reactor (not shown) of a solution containing urea and unreacted substances, and liquid ammonia.

By condensation of carbamate proposed in the invention by way of liquid and gaseous phase are served simultaneously and independently from each other in each of the designed for condensing tubes 6', which are fed into the condenser, the gas and liquid for the first time interact and mixed together with subsequent condensation of gaseous compounds and the formation of carbamate. In other words, in the space located between the gas distribution kameroy and the lower tube sheet 8 of the bottom part 11 of the capacitor, liquid and gaseous phases are not mixed together.

In the proposed invention the condenser, the gaseous phase is fed from the distribution chamber 18 through the connecting pipe 21 in the bottom of each intended for condensation pipe 6' near its lower end 6A, and the liquid phase is supplied to the condenser through the opening 19, which surrounds the gas distribution chamber 18 and, without it, gets inside each pipe 6' through the gap 22 between it and the connecting pipe 21.

Inside each pipe 6' two phases are mixed together, and after condensation of ammonia, carbon dioxide and water from the ammonia reacts with carbon dioxide, is formed carbamate.

The resulting carbamate is mixed with the carbamate, which is contained in supplied to the condenser 1 aqueous solution, and at the exit of the pipe 6' forms a solution of the carbamate, which may also contain urea.

A solution of carbamate going in the top 10 of the capacitor, of which one part of the solution through the pipes 6' drains back into the lower part 11 of the capacitor, and the other in number, which can be controlled via overflow device 14, the output from the condenser 1 through the openings 13. Taken from the condenser 1 through the opening 13 a solution of the carbamate is fed to the synthesis reactor, in which the solution contains the carb the Mat and urea to produce ammonia.

It should be noted that in the tube bundle are tubes 6, which are intended for circulation inside the capacitor 1 of the liquid phase, merging them, in particular, from the upper part 10 of the capacitor in the bottom part 11.

Proposed in the invention method provides a homogeneous and uniform distribution of gaseous compounds on all designed for condensing pipes 6' tube bundle 5 and eliminates the undesirable passage of the gas phase only through certain of the tubes of the bundle, which thereby is used in full in accordance with their parameters given at the design stage.

Proposed in the invention method can significantly compared with the currently known methods for the condensation of carbamate to increase the condensing output and efficiency of the condenser 1. In accordance with the proposed invention by way of a condensation reaction of carbamate takes place in each designated pipe 6' is essentially the same conditions. A positive impact on the efficiency of heat exchange between the liquid phase and flowing the pipe coolant, and hence on the efficiency of condensation of gaseous compounds and provides natural circulation inside the condenser liquid phase, due to which the CE is designed for condensing pipe 6' always be completely filled with a constant amount of solution, running through them all the time with the same speed.

All going in the top 10 of the condenser gases withdrawn from the condenser 1 through the opening 12 made in the top plate 3.

The synthesis reactor, desorber and the capacitor 1 are part of the so-called synthesis loop high pressure industrial equipment for production of urea. All these units operate essentially at the same pressure and are connected to each other so that at least part of the unreacted substances contained in taken from the reactor for the synthesis of the urea solution, it was possible again to return to the reactor.

The above-described method of condensation of carbamate and intended to implement it, the capacitor 1 can somehow upgrade and change.

One of possible variants of such modernization is shown in figure 3 and 4. Individual parts of the capacitor 1 of the carbamate, which structurally and functionally are the same as parts shown in Fig.1-2, indicated on these drawings the same as in figure 1 and 2 positions and will not be re-considered.

The main difference between this version from the one described above is the presence of the capacitor 1 another designated Assembly position 23 of the gas distribution chamber, which as usual is fixed inside the lower h is STI 11 of the capacitor above the gas distribution chamber 18 and is not essentially differing from it in the form.

The second gas distribution chamber 23 is composed of several sectors 24 (as shown in the figure 4 embodiment, the number is six), between which there are narrow slits 25, which between adjacent sectors passes the liquid phase.

Sector 24 are covered with the perforated wall 24A, which is located next to the lower tube sheet 8.

In this embodiment of the invention, as is more clearly shown by the example depicted in figure 4 part of the capacitor is marked with the letter B, a connecting pipe 21 out of the sectors 24 of the second gas distribution chamber 23 and go into the pipe 6', intended for condensation of carbamate, and directly connect them with the second gas chamber. To simplify figure 3 connecting pipes 21 are not shown.

A connecting pipe 21 is fixed in the holes 26 of the upper perforated walls 24A sectors, and their upper free edges 21A are located inside the tubes 6', intended for condensation of carbamate, a short distance from their lower edges.

Offered in the second embodiment of the invention the method of condensation of carbamate condenser, shown in figure 3 and 4, is essentially not different from the above-described method, the condensation of carbamate condenser shown in figures 1 and 2, except that in the second variant ha is obraznye connection coming from the gas distribution chamber 18 through the openings 20, temporarily mixed with the liquid phase over the camera 18 and gather again in the sectors 24 of the second gas distribution chamber 23.

From the second gas distribution chamber gaseous compounds through the connecting pipe 21 is directly and independently are each designed for their condensation pipe 6', which is continuously cooled by flowing tube bundle 5 outside the cooling fluid and in which they react and condense in the carbamate after mixing with the liquid phase, which is concurrent with the gas enters the pipe 6' through the annular gap 22.

In the second embodiment of the invention, moreover, the two phases are not mixed together beneath the lower tube sheet 8, which eliminates the undesirable formation inside the condenser certain paths for the movement of gases and promotes uniform distribution of gases on all pipe bundle.

The presence between adjacent sectors 24 having the form of narrow slits 25 of the intermediate channels for the passage of the liquid phase provides a uniform distribution of the liquid phase over the sectors 24 to its contact with intended for condensation pipe 6'.

The distance between adjacent sectors 24, i.e. the width of the slits 25, choose so that they could not get the gas connection. For this purpose, the capacitor 1 of the carbamate using special reflectors 27, preventing the entry slit 25 gaseous compounds.

In the variant shown in figure 3 and 4 adjacent to each other, the side walls 24b of the sectors 24 are of different height and shape, and the reflectors 27 gaseous compounds made in the form of a folded lower free ends 24C longer side walls, which from bottom to overlap the shorter wall.

Offered in the second embodiment of the invention, the capacitor 1 of the carbamate in its lower part 11 between the sectors 24 and the lower tube plate 8 also has several reflecting walls 28 beneath the pipes 6", intended for circulation of the liquid phase. The existence of such partitions allows you to more effectively control the direction of flow of the liquid phase flowing down from the pipes 6" and rising up from the slits 25, and encourages the natural circulation of the liquid phase inside the capacitor 1.

In another embodiment of the invention sector 24 of the second gas distributing device are encouraged to connect with each other (not shown in the drawings) pipes for passage of gases from one sector to another, thereby ensuring a more uniform distribution of gaseous compounds in the whole volume of the second gas distribution chamber 23. Such Tr is to be in addition, increase the stiffness and strength of the camera 23.

It should be noted that the first gas distribution chamber 18 can constructively to perform as well as the second gas distribution chamber 23, i.e. to divide it into separate sectors. In this case, for steady supply of gaseous compounds divided into sectors, the first gas distribution chamber between the sectors and the pipe 16 you must install the appropriate (not shown in the drawings) of the device of conventional type.

Proposed in the invention of the solutions shown in figure 1-4, it is preferable to use when upgrading existing capacitors flooded or even film type.

In capacitors, film-type liquid phase flows down through the tubes of the tube bundle in the form of liquid film to meet rising condensation of gaseous compounds.

Usually it is believed that the modernization of the existing capacitors either practically impossible or economically impractical, since in any case it is associated with modification of the structure of the housing of the capacitor.

Proposed in the present invention solutions provide the ability to upgrade existing capacitors without any changes in the design of housing and bottoms by placing at the bottom of the condenser gazraspredset the tion(s) camera(cameras) and connecting pipes, designed for simultaneous and independent supply of gaseous and liquid phases in all the tubes of the tube bundle, destined for the condensation of carbamate. Such modernization of the capacitor can significantly improve its efficiency and increase the condensing output.

For carrying out the invention method, the condensation of carbamate can be used and are described in WO 02/34282 flooded condensers, in which all of the tubes of the tube bundle are used for condensation of carbamate, and for recirculation of the liquid phase is a separate structurally unrelated pipe.

In this regard, it should be noted that the number and location of pipe intended for condensation of carbamate, and pipes intended for recycling part of the condensed gaseous compounds are not limited to the above only as an example of the options shown in figure 1-4, and determines in each case the working conditions or the design of the condenser.

The present invention does not exclude the possibility of making the above options are various, obvious to a person of changes and improvements within the scope of the invention defined by its formula.

1. The method of condensation of carbamate by condensation of gaseous F. the gases of carbon dioxide and ammonia in the liquid phase, representing carbamate in aqueous solution and optionally a solution containing urea and unreacted substances and liquid ammonia in the condenser apparatus of the so-called flooded type, containing a bundle of heat exchanger tubes with a certain number of pipes intended for condensation of carbamate, characterized in that each intended for condensation of carbamate pipe serves simultaneously and independently from each other gaseous and liquid phase.

2. The method according to claim 1, characterized in that the gaseous phase is served in located in the condenser apparatus for the tube bundle gas distribution chamber, collecting the gaseous phase in the gas distribution chamber and serves gaseous phase in intended for condensation of carbamate pipe through a set of connecting pipes that run from the gas distribution chamber to the pipe intended for condensation of carbamate.

3. The method according to claim 1, characterized in that the gaseous phase is served in located in the condenser apparatus for the tube bundle gas distribution chamber, collecting the gaseous phase in the gas distribution chamber and serves it in above the second gas distribution chamber, collecting the gaseous phase in the second gas distribution chamber and serves gaseous phase in p is rednaznachenie for condensation of carbamate pipe through a set of connecting pipes, passing from the second gas distribution chamber to the pipe intended for condensation of carbamate.

4. The method according to claim 2 or 3, characterized in that intended for condensation of carbamate pipe liquid phase is fed through the annular gaps between the pipes intended for condensation of carbamate, and the connecting pipes.

5. The apparatus (1) for condensation of carbamate flooded type, in which the gaseous phase carbon dioxide and ammonia is condensed into the liquid phase, representing the carbamate in aqueous solution and optionally a solution containing urea and unreacted substances and liquid ammonia, and which contains the beam (5) heat exchange tubes with a certain number of pipes (6'), inside which there is a condensation of carbamate, and the gas distribution chamber (18), which is collected is fed into the apparatus (1) gaseous phase, characterized in that it has lots of connecting pipe (21)coming from the gas distribution chamber (18) and go into the pipe (6'), for the condensation of carbamate, and thus directly connect the gas distribution chamber (18) with these pipes (6').

6. The apparatus (1) for condensation of carbamate flooded type, in which the gaseous phase carbon dioxide and ammonia is condensed into the liquid phase, representing arbamate in aqueous solution and not necessarily the solution, contains urea and unreacted substances and liquid ammonia, and which contains the beam (5) heat exchange tubes with a certain number of pipes (6'), inside which there is a condensation of carbamate, and located under the tube bundle (5) of the gas distribution chamber (18), which is collected is fed into the apparatus (1) gaseous phase, characterized in that it has a second gas distribution chamber (23)located between the first gas chamber (18) and tube bundle (5), which gathers supplied to it from the first gas distribution chamber (18) the gaseous phase, and many of the connecting pipe (21)that extend from the second gas distribution chamber (23) and go into the pipe (6'), for the condensation of carbamate, and thus directly connect the second gas distribution chamber (23) with these pipes (6').

7. The apparatus (1) for condensation of carbamate according to claim 5 or 6, characterized in that a connecting pipe (21) have a free upper end (21A), which is a short distance inside of the lower end (6A) of the pipe (6'), intended for condensation of carbamate.

8. The apparatus (1) for condensation of carbamate according to claim 7, characterized in that the diameter of the upper end (21A) of the connecting pipe (21) is smaller than the diameter of the lower end (6A) of the pipe (6')for condensing the carbs the same, due to what is between the pipes, a gap (22) for the passage of the liquid phase inside the pipe (6').

9. The apparatus (1) for condensation of carbamate according to claim 6, characterized in that the second gas distribution chamber (23) is divided into adjacent sectors (24), separated from each other by a narrow gap, forming a channel (25) for the passage between adjacent sectors (24) the liquid phase.

10. The apparatus (1) for condensation of carbamate according to claim 9, characterized in that it has reflectors (27) the gaseous phase, functionally associated with the channel (25) for the passage of the liquid phase between adjacent sectors.

11. The apparatus (1) for condensation of carbamate according to claim 10, characterized in that adjacent to each side wall (24b) of the adjacent sectors (24) have different height and shape, and reflectors (27) the gaseous phase is executed in the form of a folded lower free ends (24) of a longer side walls, which from bottom to overlap the shorter wall (24b).

12. The apparatus (1) for condensation of carbamate according to claim 5, characterized in that it has at least one reflecting wall (28)disposed between the gas distribution chamber (18) and tube bundle (5) and at least under one pipe (6")designed for circulation of the liquid phase.

13. The apparatus (1) for condensation of carbamate according to claim 6, characterized in that it has at least one reflecting wall (28), u is defined between the second gas chamber (23) and tube bundle (5) and at least under one pipe (6"), designed for circulation of the liquid phase.

14. The apparatus (1) for condensation of carbamate according to claim 9, characterized in that sector (24) are connected to each other by pipes, which from one sector to another passes the gaseous phase.



 

Same patents:

FIELD: chemical industry; methods and devices for production of carbamide.

SUBSTANCE: the invention is pertaining to the methods and devices for production of carbamide from ammonia and carbon dioxide. At realization of the method the reaction mixture from the synthesis reactor is fed in the stripper for the partial decomposition of the ammonium carbamate in the flow of the source carbon dioxide at the pressure practically equal to the pressure in the synthesis reactor. The stream of the source carbon dioxide is divided into two parts, one of which is routed into the stripper, and the other part is used as the working stream for injection of the gas stream from the stripper into the vertical condenser. The liquid stream from the stripper is fed at the stage of the subsequent decomposition of the ammonium carbamate, and the gaseous stream from the stripper is injected into the lower part of the vertical condenser for its mixing with source liquid ammonia. The liquid stream from the vertical condenser is fed into the synthesis reactor, butt from the gaseous stream absorb ammonia and carbon dioxide. The installation for production of carbamide consists of: the synthesis reactor; the scrubber for purification of the gaseous streams from the reactor from ammonia and carbon dioxide; the stripper for the partial decomposition of the ammonium carbamate; the vertical condenser, in which the mixing of the gas stream from the stripper with the source liquid ammonia takes place. The stripper is connected to the lines of feeding of the fluid stream from the reactor and the stream of the source carbon dioxide, and also is equipped with tool for injection of the gaseous stream from the stripper into the vertical condenser by the part of the stream of the source carbon dioxide. By the liquid stream the stripper is linked with the apparatuses for the subsequent decomposition of the ammonium carbamate and extraction of carbamide. The method of upgrading of the installation for production of carbamide consists in connection of the reactor of the synthesis to the stripper for the partial decomposition of the ammonium carbamate in the flow of the source carbon dioxide, in equipping the stripper with the tools for injection of the gaseous stream from the stripper into the vertical condenser with the part of the stream of the source carbon dioxide, and also in the availability of the lines of delivery of the gaseous mixture after the injector and the feeding line of the source liquid ammonia into the lower part of the vertical condenser. The technical result of the invention is the increased degree of conversion of the source reagents into carbamide at reduction of the scale of recirculation of the non-converted reactants.

EFFECT: the invention ensures the increased degree of conversion of the source reagents into carbamide at reduction of the scale of recirculation of the non-converted reactants.

11 cl, 2 ex, 2 dwg

FIELD: chemical industry; methods of production of carbamide from carbon dioxide and ammonia.

SUBSTANCE: the invention is pertaining to the method of production of carbamide from carbon dioxide and ammonia. The method of production of carbamide is realized in the reactor of synthesis with the subsequent thermal distillation from the reaction mixture of the carbamate and partially ammonia in the high-pressure apparatus at heat input by means of the steam. The separated gas phase is directed for condensation into the high-pressure condenser, where gas condensation heat is transferred to the heat-carrier with formation of the steam A. The carbamide solution from the high-pressure apparatus is fed for the ammonium carbamate decomposition into the apparatus at the average pressure with usage of the heat carrier. At that as the heat carrier use the steam condensate produced after the high-pressure apparatus in the combination the steam A. The high-pressure condenser represents the submerged condenser. The installation for production of carbamide includes the reactor of the synthesis of carbamide, the high-pressure apparatus for the thermal distillation of the carbamate and ammonia from the solution of synthesis of carbamide with the heat supply by means of the heat carrier, and also contains the apparatus for ammonium carbamate decomposition at the average pressure. As the high-pressure condenser used for the gas phase condensation the installation contains the submerged condenser. The method of the installation upgrade consists that the existing high-pressure condenser is substituted for the submerged condenser. The technical result of the invention is reduction of the power inputs due to upgrade of the equipment and the combined usage of the scheme of recuperation of the heat of the heat carriers.

EFFECT: the invention ensures the reduced power inputs, the upgrade of the equipment, the combined usage of the scheme of recuperation of the heat of the heat carriers.

12 cl, 2 dwg

FIELD: chemical industry; methods of synthesis of carbamide and the column for its realization.

SUBSTANCE: the invention is pertaining to the method of synthesis of carbamide from ammonia and carbon dioxide in the column of synthesis with the gas-liquid recycle, at which the stream of the water solution of the carbon-ammonium salts (CAS) from the area of distilling route from above or from below into the middle of the synthesis column containing the vertical cylindrical body, the corrosion-resistant material lining located on the body interior surface, the mixer and the unions of inlet and outlet of the reactants and having the located inside it perforated pipeline, which holes are disposed in pairs along the pipeline perimeter at the level of the column muddle midpoints of a column at the angle of 20° - 60° to the central axis of the column. The technical result of the invention consists in intensification of the contacting of the introduced components, the increased service life of the column lining layer and the raised conversion due to removal of the surplus of the water formed during the synthesis process.

EFFECT: the invention ensures intensification of the contacting of the introduced components, the increased service life of the column lining layer, the raised of conversion.

3 cl, 3 dwg

FIELD: chemical industry; methods and the devices for production of carbamide from ammonia and carbon dioxide.

SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the methods and the devices for production of carbamide from ammonia and carbon dioxide. The method of production of carbamide includes the interaction of ammonia and carbon dioxide in the zone of synthesis at the heightened temperatures and pressures with formation of the melt of the carbamide containing carbamide, water, ammonium carbamate, ammonia and carbon dioxide. The carbamide melt distillation conduct at the heat feeding on the two stages of pressure preferentially at 15-25°C and 2-5 kgf/cm2. The carbamide melt distillation on the first step of the pressure conduct sequentially in two zones. In the first zone the distillation is conducted adiabatically or at the heat feeding, and in the second zone - at the heat feeding in the stream of carbon dioxide. The condensation-absorption process at refrigeration of the gases of the distillation is conducted with utilization of the aqueous absorbers. The formed aqueous solutions of the carbon- ammonium salts are recycled from the stage of the condensation-absorption of the gases of the distillation of the second step to the stage of the condensation-absorption of the gases of distillation of the first step, and also from the stage of the condensation-absorption of the gases of distillation of the first step into the zone of the synthesis. The evaporation of the aqueous solution of carbamide is exercised in some steps at the heat exchange between the gases of the distillation of the first step and the aqueous solution of carbamide at the stage of the preliminary evaporation. The installation for production of carbamide consists of: the reactor of the carbamide synthesis; the device with the heat feeding from the external source for distillation of the carbamide melt produced in the reactor of the carbamide synthesis at the first step of the pressure and consisting of the column of distillation melt of the first step and the film-type heat exchanger; the device with the heat feeding for the distillation of the carbamide melt on the second step of pressure; apparatuses for evaporation at heating of the aqueous solution of the carbamide produced on the second step of distillation. The devices for condensation-absorption at refrigeration of the gases of the distillation of the both steps switch on the heat exchanger-recuperator for heat interchange between the gases of the distillation of the first step and the aqueous solution of carbamide. The installation also contains a means for feeding of ammonia and carbon dioxide into the reactor of synthesis of carbamide, feeding of the carbamide melt from the reactor of synthesis into the column of distillation of the first step, from the column of distillation of the first step into the film-type heat exchanger and from the film-type heat exchanger into the device for distillation of the second step, the aqueous solution of carbamide from the device for distilling of the second step into the heat exchanger-recuperator and from the heat exchanger-recuperator - into the apparatus for the subsequent evaporation; the gases of distillation from the device for distilling of the first step - in the heat exchanger-recuperator and from the heat exchanger-recuperator - into the device for condensation-absorption of the gases of distillation of the first step; the gases of distillation from the apparatus for distillation of the second step - into the device for condensation-absorption of the gases of distillation of the second step; the solution of the carbon-ammonium salts from the device for condensation-absorption of the gases of distillation of the second step - into the device for condensation-absorption of the gases of distillation of the first step and from the device for condensation-absorption of the gases of distillation of the first step - into the reactor of synthesis, a means for feeding of carbon dioxide into the film-type heat exchanger. The technical result of the invention is the increased degree of the heat recuperation of the production cycle and reduction of he quantity of the heat exchangers using the heating steam from the external sources.

EFFECT: the invention ensures the increased degree of the heat recuperation of the production cycle and reduction of he quantity of the heat exchangers using the heating steam from the external sources.

8 cl, 3 ex, 3 dwg

FIELD: chemical industry; devices and methods of production of carbamate.

SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to carbamatecondenserof the sinking type used in the installation for production of the synthesized carbamide from the gaseous carbon dioxide and the liquid ammonia. The condenser (1) of the sinking type contains the bundle (5) of pipes, in which the condensation of the gaseous compounds is exercised and as a result of the interaction of ammonia with carbon dioxide the carbamate is formed. The condenser differs from others by availability the condensate circulating pipe (19, 23) structurally not connected with the bundle (5) of pipes and designed for circulation of the components in the closed contour of the condenser (1)of the part of the condensed inside it gaseous compounds. The availability of the separate circulating pipe structurally not connected with the bundle of the condensation pipes and communicating with the upper and the lower parts of the condenser ensures the possibility of circulation of the carbamate passing over of the bundle of the condensation pipes, what allows to increase essentially the output of carbamate gained as a result of condensation.

EFFECT: the invention allows to raise essentially the output of carbamate gained as a result of condensation.

6 cl, 3 dwg

FIELD: chemical technology.

SUBSTANCE: invention relates to technology for preparing urea. Method involves interaction of pure ammonia and carbon dioxide in reaction space to obtain reaction mixture containing urea, carbamate and free ammonia in an aqueous solution that is treated in evaporator (1) to obtain partially purified mixture that is fed to section for isolation of urea. Diluted solution of carbamate removing from the urea isolating section is subjected for treatment in evaporator (2) and at least part of vapors formed in it is recovered to the reaction space and/or into evaporator (1). Significant part of carbamate in aqueous solution is subjected for decomposition under pressure that corresponds essentially to pressure value in reaction space. Part of decomposition products including ammonia and carbon dioxide in vapor phase is recovered into reactor and/or into the first evaporator (1) and carbamate after its partial decomposing is fed into section for isolating urea. Device for preparing urea consists of the synthesis reactor, evaporators (1) and (2) for partial decomposition of carbamate and for separation of free ammonia and carbon dioxide in vapor phase, apparatus for condensation of vapor flow, pipe-line for recover of carbamate part in aqueous solution into reactor and section for isolation of urea from its aqueous solution. Preferably, pipe-line is fitted with ejector and evaporators are fitted with apparatus for feeding carbon dioxide as a evaporating agent. Invention provides enhancing yield of urea, reducing energy consumptions and investment due to updating the technological schedule of the process.

EFFECT: improved preparing and updating methods.

30 cl, 4 dwg

FIELD: chemical technology.

SUBSTANCE: invention relates to producing urea from ammonia and carbon dioxide. Method involves preparing products of reaction in the synthesis zone as a solution containing urea, ammonium carbamate and unreacted ammonia. Part of solution obtained in synthesis of urea (preferably 10-60 wt.-%) is fed from the synthesis zone to additionally assembled zone of treatment under mean pressure at 1-4 MPa wherein gas flow is separated and subjected for absorption with ammonium carbamate solution of low pressure supplying from the section for isolation and treatment of urea. As a variant of method the invention proposes to use the combined reactor in the synthesis zone representing vertically installed or combined reactor. Enhancement of output of existing processes in synthesis of urea is achieved by feeding part of urea solution synthesized in the synthesis reactor to additionally installed zone for treatment of mean pressure including the dissociation zone, desorption zone of mean pressure and the condensation zone of mean pressure. Invention provides enhancement of output of unit for producing urea being without modification of section of high pressure.

EFFECT: improved method for producing urea.

10 cl, 4 dwg

FIELD: industrial inorganic synthesis.

SUBSTANCE: aqueous carbamate solution leaving urea recovery section at a certain temperature is decomposed by indirect heat exchange with flowing heat carrier having specified temperature. Temperature difference between aqueous carbamate solution and heat carrier is thus decreased to a value not exceeding 70°C, preferably to a value within a range of 20-40°C. Aqueous carbamate solution, prior to be fed into decomposition apparatus, is preheated in heat exchanger by stream produced in evaporation zone containing ammonia and carbon dioxide in vapor phase.

EFFECT: increased efficiency of apparatuses designed for decomposition of recycled carbamate solution.

6 cl, 2 dwg

The invention relates to the technology of complex processing of hydrocarbon fuel gases, such as methane and other natural gases, to obtain a synthesized substances

FIELD: technological processes.

SUBSTANCE: invention may be used in chemical industry. Polycrystalline silicon is produced by blowdown and thermal conversion of silanes inside silicon tubular element heated up to temperature of 750C 1000C. Internal volume of tubular element that corresponds in size to heating zone is filled with porous medium made of compacted silicon fragments in the form of needles or fibers having cross section diametre from 10 to 200 m. Density of tube internal volume filling with needle fragments prior to blowdown of silanes makes 10 60%. Dislocation of silanes inside tubular element filled with silicon fragments is realised until tube internal volume density increases - from initial one to 85 90%.

EFFECT: increased efficiency of silicon deposit in process of silanes pyrolysis, reduced energy intensity of this process.

3 cl, 2 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: synthetic gas regeneration process includes heating a reaction mixture of hydrocarbon and water vapour and/or CO2 in a reformer heated with water vapour, ensuring reforming of the reaction mixture contacting with a solid reforming catalyst. Said mixture is delivered to a tubular reformer with a fire-heated furnace to produce a mixture of required composition and temperature.

EFFECT: effective heat exchange of exhaust gas and processed gas.

9 cl, 2 dwg, 1 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: synthetic gas regeneration method involves the stages of reforming with water vapour and/or mixed CO2 hydrocarbon and water vapour in contact with catalyst active in reforming with water vapour. There is disclosed synthetic gas regeneration device containing a pre-reforming adiabatic unit for optional pre-reforming of mixed raw hydrocarbon and aqueous and/or CO2, whereat adiabatic reforming of the reaction mixture is ensured in a processed gas tubing in off-gas heat recovery section. The tubing is provided with the adiabatic zones out of the heating section and contains the solid reforming catalyst containing one or several catalytic structured elements.

EFFECT: improved application of off-gas heat.

14 cl, 2 dwg, 1 tbl, 2 ex

FIELD: engines and pumps.

SUBSTANCE: proposed furnace can be used for producing ammonia, methanol or hydrogen. A set of burners directed downward are arranged in one plane inside the said furnace. Note that the outlets of the outer burners arranged in the wall area are inclined relative to vertical. The multiple vertical parallel reaction tubes are heated from outside by the aforesaid burners. Note also that the direction of outlets of different burners can be adjusted.

EFFECT: better heat distribution and simpler control over heat transfer.

6 cl, 6 dwg

FIELD: chemistry.

SUBSTANCE: acid is obtained by catalytic oxidation of propylene, propane or isobuthylene in gas phase using molecular oxygen. Method is implemented in multitube heat exchange reactor. Reactor includes multiple parallel reaction tubes, each filled with catalyst. Tube plate adjoins bottom side of some tubes in bunch, forming output for waste gas. Tube plate features rectifier.

EFFECT: uninterrupted reaction course without acrolein decomposition, enhanced purity of reaction product.

4 cl, 1 dwg, 2 ex

FIELD: chemistry.

SUBSTANCE: synthetic gas is obtained through catalytic reforming with water vapour of hydrocarbon material in parallel, in an automatic reformer with water vapour and in one or more successive reformers with water vapour. The heat for reforming reaction with water vapour in one or more reformers with water vapour is provided for, through indirect heat exchange with combined gas streams, flowing from one or more reformers with water vapour and the automatic reformer with water vapour. The catalyst in at least one of the reformers with water vapour is granulated or is in form of a catalytic medium. A gas containing carbon oxide is added to the raw material before reforming with water vapour in the automatic reformer with water vapour and/or before reforming water vapour in one or more reformers with water vapour. Gas, containing carbon oxide with ratio of atomic hydrogen to atomic carbon less than 4.5, is added in a quantity which yields a product with molar ratio of hydrogen to carbon oxide lying, approximately, between 1.8 and 2.3.

EFFECT: increased output of synthetic gas.

9 cl, 4 tbl, 2 ex, 2 dwg

FIELD: mechanics, chemistry.

SUBSTANCE: proposed device is used for uniform distribution of two liquid phases into multiple tubes of a vertical reactor intended for chemical reactions wherein the internal space of the tubes is intended for performance of operations with a layer incorporating jet liquid streams. Note that these tubes are attached in the top and bottom parts by means of plates and closed on their external side. The distributor contains the distributive chamber located above the top plate containing feed tubes for two various liquid phases and at least one gas phase. Directly above the plate or on it, the first system of liquid distribution is arranged attached to one external feed appliance and has a circular spillway arranged outside the tubes space and furnished with orifices made in its bottom part and with a set of inlet branch pipes. One inlet branch pipe is intended for the top part of each tube of the reactor. Note that the inlet branch pipes have a tubular design, are vertically aligned, have at least one lateral orifice and one orifice located above the plate and are open at the bottom part located opposite an appropriate tube. Above the first distribution system, the second distribution system is located attached to one other external feed appliance, and contains one top and one bottom distributive trays. The bottom distributive tray contains a set of the orifices arranged on one level above inlet branch pipes of the first distribution system, and has at least one appliance setting an identical liquid level above these orifices. The top distributive tray is attached to the liquid feeding appliance and contains a set of spillways for passing liquid in the bottom distributive tray, each spillway being intended for a set of orifices of the bottom distributive tray.

EFFECT: uniform filling of multiple tubes of vertical reactor for chemical or biological reactions.

26 cl, 7 dwg

FIELD: motors and pumps.

SUBSTANCE: hydrocarbon material and dispersed catalyst are supplied to reaction chamber through the nozzle 3. Reaction chamber is formed by the central pipe 1 and the second to reactor axis pipe 2, which is made of metal nanopowders in the form of membrane permeable for hydrogen. Nozzles 6 and 7 are fixed to the external pipe 5 to supply blow-down gas and discharge hydrogen. Hydrocarbon material is supplied through the nozzle 4. Tubular-type membrane spit-flow reactor is equipped with swirl vanes for reaction mass. They are installed in reaction chamber. The reactor is also provided with pressure sensors, reagent and inlet and outlet product flow meters and thermocouple 8.

EFFECT: improved design of tubular-type reactor to perform highly endothermic gas-phase processes, increase initial raw material conversion and selectivity by olefins.

1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to production of synthesis-gas and device for obtaining it. Synthesis-gas is obtained by successive carrying out one or several endothermal and/or adiobatic reformings with water vapour and autothermal reforming with water vapour. Method includes stages of endothermal and/or adiabatic catalytic reforming with water vapour successively, where reformng with water vapour is carried out in one or two endothermal stages successively and/or in one or more adiabatic stages of reforming with water vapour successively with intermediate heating of gaseous raw material, removed from stages of adiabatic reforming, and where containing carbon monoxide gas, characterised by molar ratio of hydrogen to carbon less than 4.5, is added before at least one of endothermal or adiabatic stages of reforming with water vapour and/or before stage of autothermal reforming with water vapour. Device for obtainng synthesis-gas represents reforming system and includes optionally device of preliminary reforming for adiabatic preliminary raw material reforming; one or more devices of endothermal catalytic reforming with water vapour and/or at least first and last adiabatic installations of catalytic reforming with water vapour, connected successively; means for intermediate raw material heating between at least first and last adiabatic reforming-installations with water vapour; autothermal reforming-installation with water vapour with descending flow, connected successively with one or more installations for endothermal reforming with water vapour or with last adiabatic reforming-installation with water vapour; and means for adding carbon monoxide-containing gas, located higher along the flow of one or more endothermal reforming-installations with water vapour or higher along the flow of, at least, first and/or last adiabatic reforming-installations and/or higher along the flow of autothermal reforming-installation.

EFFECT: increase of synthesis-gas production.

10 cl, 11 tbl, 15 ex, 2 dwg

FIELD: technological processes.

SUBSTANCE: invention pertains to devices used in chemical technology and for carrying out polymerisation processes. The device for providing safe and optimum technical and economical modes of operation of a chemical reactor has a sectional cascade nickel-chromium electrical heater, a chamber for supplying the monomer, an initiator and a heat carrier into the reactor, a controller, injectors for injecting the initiator and the heat carrier into the reactor, joined to the chamber for supplying the initiator and the heat carrier into the reactor, a separation chamber, a small pressure transducer, digital ampere-voltmeters, thermal couples, unit for preliminary preparation of reagents, a pump, a container for preliminary thermostat control and a heat exchanger for final thermostat control. The unit for preliminary preparation of reagents has extra automatic regulators for putting the reagents into the monomer chamber, an initiator and a heat carrier into the reactor. The device provides for lowering energy consumption and lowering material expenses on repairing and replacing broken down chemical engineering equipment.

EFFECT: lower energy consumption and lower material expenses on repairs and replacing broken down chemical engineering equipment.

1 dwg

FIELD: chemical industry.

SUBSTANCE: the invention presents a device for formation of the dense catalyst beds and is dealt with the field of chemical industry and consists of a bin, a batching system and the device is distinguished by the fact, that it has a wire rope with a brake fastened to it. The brake is made in the form of a tubular split rod with a piggyback location of the rigid covered with elastic material rays and fastened on the wire rope with the help of a spring-loaded clamping tool, and the distance between the tiers makes 2-5 characteristic sizes of granules of the catalyst. Use of the given device allows realization of molding of the catalyst beds without destruction of the catalyst granules.

EFFECT: the invention ensures realization of molding of the catalyst beds without destruction of the catalyst granules.

3 cl, 2 dwg, 1 tbl

Up!