RU2106195C1 - Reactor for contacting of gas and liquid - Google Patents

Abstract

FIELD: petroleum refining, petrochemical, chemical and other branches of industry. SUBSTANCE: the reactor has a body accommodating a mixer in the form of a vertical tube, and an external circulation system having a pipeline for discharge of liquid from the body bottom part, a pump and a pipeline for inlet of liquid to the body upper part, connected to a nozzle installed above the mixer. The body under the mixer is divided by a horizontal partition with an overflow pipe, whose upper end is located below the upper end of the mixer; a device indicating the liquid level below the partition is installed in the bottom part of the reactor. EFFECT: improved design. 5 cl, 5 dwg

Description

 The invention can find application in the oil refining, petrochemical, chemical and other industries, for example, for the implementation of liquid-phase oxidation, chlorination, carbonylation, nitration of hydrocarbons. It can be effective to use the invention, in particular in the processes of liquid-phase oxidation of isobutane to tertiary butyl hydroperoxide, isopentane to tertiary amyl hydroperoxide, paraxylene to terephthalic acid, ethylene to acetaldehyde, isovaleric aldehyde to isovaleric acid, etc.

 Known reactor for contacting gas and liquid, including a housing, an external circulation system containing a pipeline for withdrawing liquid from the bottom of the reactor, a pump, a pipeline for introducing liquid into the upper part of the reactor and a nozzle connected to it located above the liquid level in the reactor (US patent N 4234560 C. B 01 D 47/02 and C 01 D 15/06, 1980).

 The known reactor has a low mass transfer efficiency due to the fact that the jet aeration of the layer of the liquid phase using the nozzle provides gas saturation only of the surface part of the layer.

 Also known is a reactor for contacting gas and liquid, comprising a housing, a liquid outlet pipe, a pump, a liquid inlet pipe to the upper part of the reactor, a nozzle connected to it and a coaxial mixer located below it in the form of a vertical pipe, the lower end of which is located in the working volume of the reactor under a layer of liquid (Japanese Application N 56-54172, B 01 J 10/00, 1981).

 Deepening the mixer into the liquid layer and injecting the gas phase into it from the upper part of the reactor provides gas saturation of a significant part of the layer and leads to an increase in mass transfer efficiency compared to the reactor considered above.

 However, the depth of penetration of the mixer into the liquid layer in the known reactor is limited due to the fact that the degree of injection of the gas phase sharply decreases with increasing height of the depth (with increasing back pressure of the liquid column). Therefore, the use of this reactor is limited by its small size and capacity. When using the known reactor of large unit capacity for a number of technological processes, the mass transfer efficiency is insufficient, while the working volume of the reactor is inefficiently used, since the zone of the working volume below the mixer is practically not used for contacting.

 The objective of the invention is to increase the efficiency of mass transfer, a more rational use of the working volume while increasing the productivity of the reactor.

 To solve this problem in a reactor for contacting gas and liquid, which includes a housing, a mixer installed in it in the form of a vertical pipe and an external circulation system containing a liquid outlet pipe from the lower part of the body, a pump and a liquid inlet pipe into the upper part of the body connected to the nozzle installed above the mixer, the housing under the mixer is divided by a horizontal partition on the overflow pipe, the upper end of which is located below the upper end of the mixer, while in the lower part of the reactor and the unit is installed, the fixing liquid level below the partition.

 The fluid inlet pipe to the upper part of the housing can be connected to additional nozzles, under each of which a mixer is installed with a lower end located above the partition.

 A pipe can be installed coaxially with it in the mixer, the upper end of which is located below the upper end of the mixer, and the lower - below the partition.

 The fluid inlet pipe to the upper part of the housing can be connected to additional nozzles, under each of which a vertical pipe with a lower end below the partition is installed. The partition may have perforation.

 Devices for fixing the liquid level below the partition can be made, for example, in the form of overflow nozzles installed at the liquid level, vertical partitions or pockets with overflow edges located at the liquid level, which can be equipped with level control devices and the like. The level in the upper part of the reactor is fixed by the position of the upper end of the overflow nozzle. The lower end of the overflow can be gear.

 The nozzle and the upper end of the mixer can be located in the injection chamber, which includes a housing with a pipe connected to the upper part of the reactor and a gas inlet pipe.

 Dispersant chippers may be located under the lower edge of the mixers.

 The gas inlet pipe can be connected to the gas space (above the liquid layer) under the upper housing cover or under the partition, while the gas outlet pipe is connected respectively to the gas space under the partition and the cover.

 If the gas phase is completely exhausted during the reaction, the gas outlet pipe may be absent.

 The fluid inlet pipe may be located in the fluid layer above or below the partition, and the outlet may be located under or above the partition, respectively.

 A heat exchanger can be installed on the piping of the external circulation system to control the temperature in the reactor. For the same purpose, the reactor vessel may be equipped with a jacket.

 The partition dividing the reactor vessel may be blind and have only drainage holes to release the apparatus from liquid or perforated. The partition may be flat, horizontal or have a curved surface, for example, spherical, elliptical, etc., convex up or down.

 The proposed reactor can be used as a single unit in multi-stage schemes with series or parallel connection of several separate reactors. It is possible to arrange multi-stage circuits in a single housing located vertically or horizontally.

 In FIG. 1-5 illustrate examples of the design of a reactor for contacting gas and liquid.

 The reactor (Fig. 1) includes a housing 1, a mixer installed therein 2. an external circulation system comprising a fluid outlet pipe 3 from the bottom of the housing, a pump 4, a fluid intake pipe 5 to the upper part of the housing connected to an injector 6 installed above the mixer coaxially with it. The reactor vessel is divided into upper 7 and lower 8 chambers by a horizontal partition 9 with an overflow pipe 10.

 In the lower part of the reactor, a device is installed that fixes the liquid level below the baffle and consists of a discharge section 12 formed by a vertical overflow baffle 11, hermetically connected to the reactor vessel and having an overflow edge at the liquid level, which also contains nozzles 13 for the level gauge 14 connected to the control valve 15 on the line 16 of the liquid outlet from the reactor.

 The reactor has a pipe 17 for introducing liquid and a pipe 19 for outputting gas.

 The partition 9 has perforation holes 20. A heat exchanger 21 is installed on the pipe 5.

 In FIG. Figures 2 and 5 show reactor variants in which a pipe 22 is installed coaxially with the mixer 2, the upper end of which is located below the upper end of the mixer and the lower end is below the partition 9 above and below the liquid layer in the lower chamber.

 The fluid inlet pipe 5 to the upper part of the reactor vessel shown in FIG. 3 and 4, connected to an additional nozzle, under which a vertical pipe 23 is installed with a lower end below the partition 9 above and below the liquid layer in the lower chamber.

 Under the pipe 23 (Fig. 4), a fender-dispersant 24 is installed.

 For liquid injection, the reactor has a pipe 25 located, for example, under a liquid layer in the upper chamber (Fig. 1 and 2), a pipe 26 connected to a pipe 3 of the circulation system 6 (Fig. 3, 5), a pipe 27 located under the layer liquid in the lower chamber (Fig. 4).

 For liquid withdrawal, the reactor has a pipe 23 located in the lower part of the discharge section (Fig. 1), at the level of the liquid layer in the lower chamber (Fig. 2, 3), in the middle of the discharge section (Fig. 5), in the lower part of the layer liquid in the upper chamber (Fig. 4).

 To introduce gas, the reactor has a pipe 29 located above the liquid layer in the lower chamber (Fig. 1, 3), above the liquid layer in the upper chamber (Fig. 2, 4).

 The device that fixes the liquid level below the baffle in the reactor (Fig. 2 and 3) is an overflow pipe 28, in the reactor at (Fig. 4) there is a level gauge 14 installed in the pipes 13 in the lower chamber and connected to the valve 15 on the outlet pipe 16 liquid from the upper chamber, and in the reactor (Fig. 5) - vertical overflow baffle 11 and overflow pipe 28 mounted at the liquid level in the discharge section 12.

 In the reactor (Fig. 5), the nozzle 6 and the upper end of the mixer are installed in the injection chamber 30, consisting of a housing 31 with upper 32 and lower 33 bottoms. Moreover, the chamber has a pipe 34 in the upper part, connected by a pipe 35 to a pipe 36 in the upper part of the reactor vessel 1.

 The nozzle 6 is connected to the pipeline 5 of the circulation system.

 Gas is introduced into the reactor through a pipe 37 connected to a pipe 35 or to a pipe 34 of the chamber 30.

 The camera body 30 may have a cylindrical shell 31 (see section A-A), with a coaxial arrangement of the shell, nozzle, and mixer. In this case, the nozzles 34 and 29 are installed tangentially to the shell.

 The reactor operates as follows.

 The reactor is filled with liquid. In this case, the liquid levels are fixed in the upper chamber by the upper end of the overflow pipe 10, and in the lower chamber by the edge of the overflow of the partition 11 (Fig. 1), pipe 28 (Figs. 2, 3, 5), control devices (Figs. 1, 4), consisting of a level meter 14 and a valve 15 on the pipeline for withdrawing liquid from the reactor 16. The liquid circulates in the lower chamber - upper chamber system using pump 4 through pipelines 3, 5.

 The liquid is supplied to the reactor through a pipe 25, which is located in the lower part of the liquid layer in the upper chamber (Fig. 1, 2), through the pipe 27 in the lower part of the liquid layer in the lower chamber (Fig. 4), as well as through a pipe 26 connected with the pipeline 3 of the circulation system (Fig. 3, 5).

 The liquid is discharged from the reactor through a pipe 28 located in the discharge section 12 of the lower chamber of the reactor (Fig. 1), in the upper part of the liquid layer of the lower chamber of the reactor (Figs. 2, 3), in the lower part of the liquid layer of the upper chamber of the reactor (Fig. 4 ), in the middle of the discharge section (Fig. 5).

 Gas is introduced into the reactor through the pipe 29 into the superlayer space of the lower chamber (Fig. 1, 3), into the superlayer space of the upper chamber (Fig. 2, 4) or through a pipe 37 connected either to the pipe 35 or to the pipe 29 of the chamber 30.

 Gas is removed from the reactor through a pipe 19 located in the superlayer space of the upper chamber of the reactor (Fig. 1), in the superlayer space of the lower chamber of the reactor (Fig. 2), and can exit the reactor together with the liquid through the pipe 28 (Fig. 5), may not be removed from the reactor when it is completely exhausted during the process (Fig. 3, 4).

 When the fluid is circulated by the pump 4, the nozzle 6 injects gas from the superlayer space of the upper chamber 7 into the liquid layer of the upper chamber through the mixers 2 (Fig. 1-5), as well as through the annular space delighted by the pipes 2 and 22, while the gas is simultaneously injected through pipe 22 into the superlayer space of the lower chamber 8 (Fig. 2) or into the liquid layer (Fig. 5).

 Additional nozzles 38 and vertical pipes 23 provide gas injection from the upper chamber to the lower: into the superlayer space (Fig. 3), under the liquid layer (into the reaction volume (Fig. 4).

 The gas-liquid mixture leaving the mixers 2, pipes 22 and pipes 23 is dispersed in the reaction volumes of the upper and lower chambers: on the surface of the partition 9 (Fig. 1-5), on the baffle-dispersant 24 (Fig. 4), on the surface of the bottom of the body reactor (Fig. 5), on the surface of the liquid layer in the lower chamber (Fig. 2, 3).

When the reactor is operating, additional contact zones arise:
in the overflow pipe 10, in countercurrent mode of movement of the circulating liquid and gas in the overflow pipe (Fig. 1-5);
in the superlayer space in the lower chamber of the reactor when gas is in contact with jets of liquid flowing from an overflow pipe (Fig. 1-5), from perforation holes 20 of partition 9 (Fig. 1), from pipes 22 and 23 (Fig. 2, 3) ;
in the liquid layer in the lower chamber of the reactor in connection with aeration of the layer with liquid jets (Fig. 1-5), as well as in connection with the gas saturation of the liquid layer in the lower chamber with a gas-liquid mixture flow directed to the bottom of the layer by pipes 23 and 22 (Fig. 4, 5).

 The separation of the working volume of the reactor by a partition with an overflow pipe into the upper and lower chambers allows you to create additional contact zones, including in the lower part of the reactor, not used in the prototype, for contacting in reactors of greater unit power with a large volume and height.

 Installing the upper end of the overflow pipe below the upper ends of the mixers allows you to fix the level of the liquid layer in the upper chamber and ensures stable operation of the nozzle and mixer.

 Fixing the level of the liquid layer in the lower chamber also stabilizes the operation of the pipes lowered into the lower chamber and allows to withstand the optimal conditions for the jet coating of the layer.

 The two-pipe mixer formed by pipes 2 and 22 (Fig. 2, 5) allows gas to be injected simultaneously in the reaction volume of both chambers using a single nozzle, which is also provided by the location of the upper ends of the mixer pipes when creating an overpressure chamber between the upper ends of the pipes.

 The equipment of the reactor with additional autonomous nozzles and mixers introduced into the lower chamber of the reactor allows to stabilize and intensify the operation of the lower chamber.

 The location of the nozzle and the upper end of the mixer in the injection chamber allows gas to be introduced through the chamber and mixer directly into the liquid layer, bypassing the gas space above the liquid layer, which is preferable in a number of processes, for example, from safety conditions when introducing a gaseous oxidizing agent in liquid-phase hydrocarbon oxidation. The tangential arrangement of the nozzles for introducing gas into the chamber 29 (Fig. 5, section AA) allows to reduce the hydraulic resistance of the gas paths and thereby increase the degree of gas injection, improves the mixing conditions of the gases entering the chamber through these nozzles, in a swirling flow, stabilizes the operation of the nozzle.

 Thus, the invention allows to increase the efficiency of mass transfer, to more efficiently use the working volume of the reactor while increasing its productivity.

Claims (5)

 1. A reactor for contacting gas and liquid, including a housing, a mixer installed in it in the form of a vertical pipe and an external circulation system comprising a fluid outlet pipe from the bottom of the housing, a pump and a fluid intake pipe to the upper part of the housing, connected to the nozzle mounted above mixer, characterized in that the housing under the mixer is separated by a horizontal partition with an overflow pipe, the upper end of which is located below the upper end of the mixer, while at the bottom of the reactor A device is installed that fixes the liquid level below the septum.  2. The reactor according to claim 1, characterized in that the pipeline for introducing liquid into the upper part of the housing is connected to additional nozzles, under each of which a mixer is installed with a lower end located above the partition.  3. The reactor according to claims 1 and 2, characterized in that a pipe is installed coaxially with it in the mixer, the upper end of which is located below the upper end of the mixer, and the lower - below the partition.  4. The reactor according to claims 1 to 3, characterized in that the liquid inlet pipe to the upper part of the reactor is connected to additional nozzles, each of which has a vertical pipe with a lower end below the partition.  5. The reactor according to claims 1 to 4, characterized in that the partition has perforation.

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