Synthesis reactor inlet mixer

Abstract

The utility model relates to a reactor inlet mixer and can be used for producing fertilizers, and more particularly for producing urea. Claimed is an inlet mixer for a synthesis reactor R, comprising a means A for delivering a liquid, a means B for delivering a gas, and a shell S, wherein the means A and B have a bottom part, a middle part and a top part, the bottom part of the means A and B is disposed outside of both the reactor R and the shell S, the middle part of the means A and B is disposed inside the reactor R but outside the shell S, and the top part of the means A and B is disposed inside of both the reactor R and the shell S, wherein the shell S is fastened to an inner part of the reactor R, and the shell S has perforated partitions H mounted therein. The technical result consists in an increase in the operating efficiency of a reactor as a result of the efficient mixing of the starting reagents and the elimination of dead zones in the bottom part of the reactor. In addition, the resistance to inlet streams entering the reactor is low.

Description

[0001] MTIK B01F23 / 20

[0002] MIXER IN THE SYNTHESIS REACTOR

[0003] Field of technology

[0004] The utility model relates to a mixer in a synthesis reactor and can be used for the production of fertilizers, in particular, for the production of urea.

[0005] State of the art

[0006] From patent RU2241531C1, published on 10.12.2024, a reactor mixer for carrying out chemical processes is known, including a housing and input and output pipes for reagents, characterized in that the housing contains at least two series-connected coaxial vortex chambers, each of which has a tangential input and axial output pipes, wherein the tangential input pipes of the chambers are arranged in such a way that the direction of rotation of the tangential flows in all chambers is the same, and the axial output pipe of each preceding chamber is introduced into the cylindrical housing of the subsequent chamber in such a way that its inlet opening is located in the direction of movement of the reagents after the inlet opening of the tangential input pipe.

[0007] A drawback of the existing technical solution is the small size of the "swirl generator" inside the synthesis reactor, limited by the diameter of the reactor inlet. This makes the use of the lower zone of the reactor ineffective (stagnant zones form without active mixture movement), leading to a decrease in reactor efficiency.

[0008] From patent RU100430U1, published on 20.12.2010, a gas-liquid reactor is known, comprising a vertical body with nozzles for the input of reagents and the output of reaction products and a mixer located in the lower part of the body, including a coaxial pipe and a vortex chamber, having a tangential inlet nozzle connected to the input nozzle of the first reagent, and an axial outlet nozzle directed towards the bottom of the reactor, wherein the coaxial pipe is inserted into the cylindrical body of the vortex chamber, the upper end of the coaxial pipe is connected to the input nozzle of the second reagent, characterized in that the lower part of the reactor contains a screen located near the bottom of the reactor opposite the outlet nozzle of the mixer. A disadvantage of the known technical solution is that the flow passing coaxially through the mixer does not participate in mixing until the last moment (passes through the mixer).This can prevent effective mixing with other feed streams entering the mixer at the mixer outlet, leading to reduced mixing efficiency and reactor operation. Furthermore, the mixer outlet has a typical cylindrical shape, making the lower zone of the reactor ineffective (stagnant zones form without active mixture movement) and, ultimately, reducing reactor efficiency.

[0009] The closest analog can be chosen to be the technical solution disclosed in patent RU2173212C1, published on 10.01.2001, which discloses a urea synthesis column containing a vertical cylindrical body, a lining made of corrosion-resistant material placed on the inner surface, a mass-exchange device and nozzles for the input and output of reagents, characterized in that the mass-exchange device is made in the form of a nozzle, a receiving and mixing chamber, a diffuser connected in series, installed on the nozzle for the input of reagents and enclosed in a perforated casing.

[0010] A drawback of the known technical solution is the relatively low flow rate of the mixture in the lower part of the reactor at the outlet of the perforated shell, which reduces the reactor volume utilization and, ultimately, leads to a decrease in its operating efficiency. Furthermore, the combination of the reactant injection nozzle, diffuser, and mixer outlet through the perforated surface creates increased resistance to the inlet flow into the reactor. Thus, the disadvantage of the known technical solution is low synthesis reactor efficiency with high inlet flow resistance.

[0011] Disclosure of the essence of the utility model

[0012] The objective of the claimed utility model and its technical result is to increase the efficiency of the reactor by effectively mixing the initial reagents and the absence of stagnant zones in the lower part of the reactor with low resistance to the inlet flows into the reactor. To solve the above problem and achieve the claimed technical result, a mixer is proposed for the synthesis reactor R, including

[0013] liquid supply means A,

[0014] gas supply facility B,

[0015] S-ring,

[0016] whereby means A and B have a lower, middle and upper part,

[0017] the lower part of means A and B is located outside the reactor R and the shell S, the middle part of means A and B is located inside the reactor R and outside the shell S, the upper part of means A and B is located inside the reactor R and the shell S, the shell S is fixed in the inner part of the reactor R,

[0018] and perforated partitions H are installed inside the shell S.

[0019] By feed means is meant the means for feeding the starting reagents into a reservoir, for example, into a synthesis reactor.

[0020] A shell is an open cylindrical or conical structural element.

[0021] The lower part of the reactor refers to the part of the reactor in which the mixer is located.

[0022] A partition is an internal structure that divides a space into parts.

[0023] A perforated baffle is a baffle with openings. The presence of means A and B ensures the introduction of liquid and gas into reactor R. The presence of a shell S ensures flow movement in the lower part of reactor R, similar to a circulation pipe. The presence of perforated baffles H ensures effective initial mixing, with part of the flow passing through the baffle openings and part around them. These two parts of the flow then intersect, ensuring effective mixing of the initial reactants. The aforementioned elements do not create active resistance to the flow of the incoming flows.

[0024] Thus, movement is created throughout the entire volume of the reactor R in the lower section, eliminating stagnant zones and ensuring efficient mixing of the feedstock reactants. Consequently, the above-mentioned design improves reactor efficiency by effectively mixing the feedstock reactants and eliminating stagnant zones in the lower section of the reactor, while maintaining low resistance to inlet flows.

[0025] The above combination of features is sufficient to achieve the claimed technical result. Furthermore, the following features, inherent in specific embodiments, enable the claimed technical result to be achieved most effectively.

[0026] Preferably, the liquid is ammonia, a solution of ammonium carbonate salts, or a mixture thereof.

[0027] Ammonium carbonate solution is a mixture containing ammonium carbamate, water, and free ammonia.

[0028] The supply of a solution of ammonium carbonate salts containing free ammonia in combination with carbon dioxide increases the efficiency of mixing of flows due to the immediately beginning of a violent reaction of formation of ammonium carbamate.

[0029] Preferably, the gas is carbon dioxide.

[0030] The supply of carbon dioxide in combination with a solution of ammonium carbonate salts containing free ammonia increases the efficiency of mixing of flows due to the immediately beginning of a violent reaction of formation of ammonium carbamate.

[0031] In the preferred embodiment, the partitions H are segmental.

[0032] A segmental baffle is a baffle that is shaped like the tank in which it is located and has a cutout to allow free passage of gas and / or liquid.

[0033] This shape allows for complex flow patterns, with part of the mixture passing through the openings in the baffle and part of it bending around it. Further intersection of these two flow paths promotes additional mixing and, ultimately, further enhances reactor efficiency with low inlet flow resistance.

[0034] In a preferred embodiment, the middle portion of means A and B have openings.

[0035] The presence of openings in the middle of units A and B helps reduce the formation of stagnant zones in the lower part of the reactor and ensures efficient mixing of the feedstock reactants. This further enhances reactor efficiency with low inlet flow resistance.

[0036] In the preferred embodiment, the shell S has a cylindrical shape.

[0037] This shape most naturally facilitates the organization of mixture movement in the lower part of the reactor, following the principle of a circulation tube. This results in the most intense circulation of the mixture in the lower part of the reactor and further contributes to increased reactor efficiency with low resistance to inlet flows.

[0038] In a preferred embodiment, the ratio ds / dR of the diameter ds of the base of the shell S and the diameter dR of the synthesis reactor R is 0.4-0.8.

[0039] The specified ratio allows for the creation of the most intensive circulation movement of the mixture in the lower part of the reactor and additionally contributes to increasing the efficiency of the reactor with low resistance to the inlet flows into the reactor.

[0040] In a preferred embodiment, the ratio of the height hs of the shell S and the diameter dR of the reactor R is 0.4-0.8.

[0041] The specified ratio allows for the creation of the most intensive circulation movement of the mixture in the lower part of the reactor and additionally contributes to increasing the efficiency of the reactor with low resistance to the inlet flows into the reactor.

[0042] In a preferred embodiment, the shell S comprises 2 perforated partitions H.

[0043] For example, 2-4 perforated partitions H can be installed inside the shell S.

[0044] The specified number of baffles allows for optimal initial mixing of the reactants without creating additional resistance to mixture flow. This further enhances reactor efficiency with low inlet flow resistance.

[0045] In the preferred embodiment, the angle of inclination of the baffles H relative to the base of the shell S is 10-40°. This angle creates optimal conditions for the intersection of the mixture portions passing through the perforations and the segmented cutout of the baffle, ensuring optimal mixing. This further enhances reactor efficiency with low inlet flow resistance.

[0046] In the preferred embodiment, the area S of the free cross-section of the partitions H is 5-20%, where the area of ​​the free cross-section is the ratio of the sum of the areas

[0047] openings of the partition H to the total area of ​​the partition H, S =

[0048]

[0049] where Si is the area S H

[0050] holes, n - number of holes, SH - total area of ​​the partition H.

[0051] The total area of ​​the partition is understood to be the area of ​​the partition taking into account the area of ​​the openings.

[0052] The specified free cross-sectional area allows for optimal distribution of the reactant mixture as it passes through the perforations and segmented cutout of the baffle. This further enhances reactor efficiency with low inlet flow resistance.

[0053] Brief description of the drawings

[0054] The drawings are presented for a better understanding of the utility model, however, it will be obvious to a person skilled in the art that the disclosed utility model is not limited to the variant shown in them.

[0055] Fig. 1 schematically shows the general view of the mixer in the reactor according to the present utility model.

[0056] Fig. 2 shows a schematic diagram of a mixer in a urea synthesis reactor (side view).

[0057] Fig. 3 schematically shows a mixer in a urea synthesis reactor (top view).

[0058] Fig. 4 schematically shows some possible variants of the mixer according to this utility model.

[0059] All figures show diagrams and are not drawings.

[0060] Designations: A - liquid supply means,

[0061] B - gas supply means,

[0062] C - liquid supply means,

[0063] Ai is the lower part of the tool A,

[0064] Ag is the middle part of the product A,

[0065] Az is the upper part of the means A,

[0066] Bi - the lower part of the tool B,

[0067] Вг - the middle part of the product B,

[0068] BZ - the upper part of the tool B,

[0069] R - fusion reactor,

[0070] S - shell,

[0071] H - perforated partitions,

[0072] hs - height of the shell S,

[0073] ds - shell diameter S,

[0074] dR is the diameter of the synthesis reactor R,

[0075] a - the angle of inclination of the partitions H relative to the base of the shell S,

[0076] Implementation of a utility model

[0077] The described embodiment examples are provided for illustrative purposes only. Those skilled in the art will readily recognize that other embodiments are possible without altering the essence of the utility model.

[0078] All units of the claimed device are interconnected by assembly operations and are in functional and structural unity.

[0079] Fig. 1 shows a schematic representation of a mixer in a reactor according to the present utility model. The mixer is located in the lower part of the synthesis reactor R. The mixer consists of a liquid supply means A, a gas supply means B, and a shell S. In this case, means A and B are conditionally divided into three parts - lower (Ai, Bi), middle (A2, B2) and upper (Az, Bz).

[0080] The lower part is located outside the reactor R and the shell S, the middle part is located inside the reactor R and outside the shell S, and the upper part is located inside the reactor R and the shell S. The shell S is fixed inside the synthesis reactor R. Perforated segmented partitions H are installed inside the shell S. The middle part of means A and B has openings. A means C for feeding liquid can also be installed in the mixer.

[0081] The claimed device operates as follows (see Fig. 2, 3).

[0082] The operating principle is based on mixing the reactants using circulation in a shell S. A cylindrical shell S, open on both sides and with a base diameter of ds and a height of hs, is installed in the lower part of a reactor R with a diameter of dR. A solution of ammonium carbonates and ammonia are fed into the shell through means A, and carbon dioxide is fed through means B, after which the initial reactants move together from the bottom up. For better initial mixing, perforated segmental baffles H are installed inside the shell S at an angle a to the base of the shell S. Part of the flow passes through the holes in the baffles H, and the other part goes around them. These two parts of the flow then intersect, which allows for effective mixing of the initial reactants. The flow exits the upper part of the shell S. Part of the flow is directed upward for further reactions, and the other part, according to the principle of a circulation pipe, is directed downward.Movement is created by the difference in density—the liquid phase with a higher density descends into a zone with a lower density (the density at the reactor inlet is lower than further up the reactor due to the supply of gas as one of the reactants). The descending liquid then enters the lower part of the shell S and passes through its interior again, creating circulation. Thus, movement is ensured throughout the entire volume of the reactor R at the bottom, eliminating the formation of stagnant zones and ensuring efficient mixing of the initial reactants. This allows for a high degree of conversion of carbon dioxide to urea and maximum reactor efficiency. The middle section of reactant inlet means A and B may have openings that provide oxygen-containing carbon dioxide to the specified zone (to protect the bottom lining from corrosion) and drainage of solutions from the reactor during production shutdowns. Also, as can be seen from Fig.4, the number of input means can be three - for carbon dioxide (mean B) and separately for a solution of ammonium carbonate salts (mean A) and for ammonia (mean C).

[0083] The test results of the claimed device are presented in the table below. 5

[0084] Table 1

[0085]

[0086]

[0087]

[0088] Thus, the claimed device ensures an increase in the reactor operating efficiency due to the effective mixing of the initial reagents and the absence of stagnant zones in the lower part of the reactor with low resistance to the inlet flows into the reactor.

Claims

Utility model formula 1. A mixer in the synthesis reactor R, including liquid supply means A, gas supply facility B, S-ring, whereby means A and B have a lower, middle and upper part, the lower part of means A and B is located outside the reactor R and the shell S, the middle part of means A and B is located inside the reactor R and outside the shell S, the upper part of means A and B is located inside the reactor R and the shell S, the shell S is fixed in the inner part of the reactor R, and perforated partitions H are installed inside the shell S.

2. The mixer according to item 1, characterized in that the liquid is ammonia, a solution of ammonium carbonate salts, or a mixture thereof.

3. The mixer according to item 1, characterized in that the gas is carbon dioxide.

4. The mixer according to I.1, characterized in that the partitions H are segmented.

5. The mixer according to item 1, characterized in that the middle part of means A and B have openings.

6. The mixer according to item 1, characterized in that the shell S has the shape of a cylinder.

7. The mixer according to item 6, characterized in that the ratio ds / dR of the diameter ds of the base of the shell S and the diameter dR of the synthesis reactor R is 0.4-0.

8.

8. The mixer according to item 1, characterized in that the ratio hs / dR of the height hs of the shell S and the diameter dR of the reactor R is 0.4-0.

8.

9. The mixer according to item 1, characterized in that the shell S contains 2 perforated partitions H.

10. The mixer according to item 1, characterized in that the angle a of inclination of the partitions H relative to the base of the shell S is 10-40°.

11. The mixer according to item 1, characterized in that the area S of the free cross-section of the partitions H is 5-20%, where the area of ​​the free cross-section is the ratio of the sum of the areas of the openings of the partition H to the total area of ​​the partition H, S = where Si is the area of ​​the hole, n is the number of holes, S H SH - total area of ​​partition H.

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