CN215996580U

CN215996580U - Evaporation mixer and methylamine synthesis device

Info

Publication number: CN215996580U
Application number: CN202122055195.8U
Authority: CN
Inventors: 郑可嘉; 陈峰华; 刘立新
Original assignee: Beijing Xinmeige Engineering Design Co ltd
Current assignee: Beijing Xinmeige Engineering Design Co ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2022-03-11
Anticipated expiration: 2031-08-30

Abstract

The utility model provides an evaporation mixer and a methylamine synthesizing device, wherein the evaporation mixer comprises: the horizontal type shell is internally and oppositely provided with a steam evaporator and a product heat exchanger; the steam evaporator comprises a heating tube bundle and a steam feeding and discharging end socket, and the product heat exchanger comprises a heat exchange tube bundle and a product feeding and discharging end socket; and the methylamine product enters the horizontal shell so as to recover the heat of the methylamine product. The evaporation mixer disclosed by the utility model can effectively reduce the equipment occupation area of an evaporation mixing system, reduces the overall height of the evaporation mixing equipment, and is convenient to install on site while reducing the energy consumption of conveying equipment. The methylamine synthesis device can reduce the energy consumption of unit products, improve the yield of dimethylamine, reduce the operation load of a downstream product separation system on the premise of improving the product competitiveness, and lay a foundation for saving energy consumption and material consumption of subsequent rectification separation.

Description

Evaporation mixer and methylamine synthesis device

Technical Field

The utility model relates to the technical field of chemical production, in particular to an evaporation mixer and a methylamine synthesizing device.

Background

Methylamine is an important basic organic chemical raw material, is widely applied to various industries of national economy, and is a basic raw material for industries of pesticides, medicines, synthetic dyes, synthetic resins, chemical fibers, solvents, surfactants, high-energy fuels, photographic materials and the like.

Methylamine is divided into monomethylamine, dimethylamine and trimethylamine, and is generally produced by a gas-phase catalytic reaction method of methanol and ammonia in industry, wherein the method takes methanol and liquid ammonia as raw materials and adopts the gas-phase catalytic reaction to prepare the methylamine, and the main reactions are as follows:

CH₃OH+NH₃→CH₃NH₂+H₂O+Q

2CH₃OH+NH₃→(CH₃)₂NH+2H₂O+Q

3CH₃OH+NH₃→(CH₃)₃N+3H₂O+Q

the method has rich raw material sources, low price, large-scale continuous production, lower requirements on equipment and materials, easy satisfaction of process conditions, flexible adjustment of the product proportion of the three types of methylamine according to market demands, and is also the most common production method in the current methylamine industry, and the current methylamine factories in China all adopt the process to produce methylamine.

In the method, liquid methanol, liquid circulating material and liquid ammonia are adopted as raw materials, a plurality of heat exchangers and vertical containers are adopted during feeding, the raw materials are connected through pipelines to form an evaporation mixing system of the raw materials, the raw materials methanol and the liquid ammonia are gasified, and the gasified materials are introduced into a reactor for reaction.

The existing evaporation mixing system has the disadvantages of large equipment quantity, large occupied space and high installation height, which causes higher energy consumption of conveying equipment; and the heat emitted after the gas-phase catalytic reaction is not effectively utilized in the evaporation mixing process, so that the direct loss of heat and the waste of energy are caused, the cost of unit products is indirectly improved through energy consumption, and the market competitiveness is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an evaporation mixer and a methylamine synthesis device, which can reduce equipment for preheating and mixing raw materials, simplify the feeding process, fully recover heat released after gas-phase catalytic reaction, and fundamentally reduce the energy consumption and production cost of unit methylamine products.

The utility model provides an evaporative mixer, comprising: the horizontal shell is provided with a horizontal shell,

a steam evaporator and a product heat exchanger are oppositely arranged in the horizontal shell;

the steam evaporator comprises a heating tube bundle and a steam feeding and discharging end socket, and the product heat exchanger comprises a heat exchange tube bundle and a product feeding and discharging end socket;

and the methylamine product enters the horizontal shell so as to recover the heat of the methylamine product.

Furthermore, the horizontal shell comprises a mixing chamber for mixing and heating the raw materials, and the heating tube bundle and the heat exchange tube bundle are both arranged in the mixing chamber.

Furthermore, the steam feeding and discharging seal head and the product feeding and discharging seal head are both one and are respectively arranged at two ends of the horizontal shell.

Further, the heating tube bundle and the heat exchange tube bundle are both U-shaped tube bundles.

Further, the horizontal shell further comprises an evaporation chamber positioned at the top of the mixing chamber, the evaporation chamber is communicated with the mixing chamber, and a demister used for defoaming the evaporation gas is installed in the evaporation chamber.

The utility model provides an including above-mentioned evaporation mixer's methylamine synthesizer, enter into the methylamine reactor after the methylamine synthetic raw materials reheating in the evaporation mixer and carry out the synthetic reaction, be provided with multistage catalytic unit in the methylamine reactor, every section catalytic unit includes at least one deck molecular sieve catalyst layer.

Further, still including carrying out reheating unit of reheating, reheating unit is including steam heater, raw materials pre-heater and the electric heater that sets gradually, steam heater's feed inlet with evaporation mixer's discharge gate is connected, electric heater's discharge gate with the feed inlet of methylamine reactor is connected.

Furthermore, the raw material preheater comprises a shell pass inlet and a shell pass outlet, the shell pass inlet is connected with a discharge port of the methylamine reactor, and the shell pass outlet is connected with a feed port of the product heat exchanger.

Furthermore, a circulating material tank and a methanol raw material tank are arranged at the upstream of the evaporation mixer, and circulating materials and methanol are respectively fed into the evaporation mixer through a circulating material feeding pump and a methanol feeding pump.

Further, still include the ammonia inlet pipe, the evaporation blender reaches be provided with the ammonia feed inlet on the methylamine reactor respectively, the ammonia passes through the ammonia feed inlet lets in respectively the evaporation blender reaches the methylamine reactor.

According to the evaporation mixer, the steam evaporator and the product heat exchanger are integrated on the evaporation mixer, so that the occupied area of the evaporation mixing system can be effectively reduced, the overall height of the evaporation mixing device is reduced, and the energy consumption of the conveying device is reduced and the on-site installation is facilitated.

Through letting in the methylamine product in the product heat exchanger that sets up in the evaporation mixer, can make the methylamine product that has a large amount of reaction heats carry out the heat transfer through the reaction raw materials in heat exchange tube bank and the mixing chamber, make the heat that the reaction generated obtain recycle in the mixed evaporation link of raw materials, effectively reduceed the energy consumption and the manufacturing cost of unit product, greatly improved product competitiveness.

The molecular sieve catalyst layer included in the methylamine reactor can further react trimethylamine with ammonia gas in a form of adsorbing the generated product by the molecular sieve, so that the conversion rate of the dimethylamine is effectively improved.

Through the methylamine synthesis device comprising the evaporation mixer and the methylamine reactor, the energy consumption of unit products can be reduced, the yield of dimethylamine can be improved, the operation load of a downstream product separation system can be reduced on the premise of improving the product competitiveness, and a foundation is laid for saving energy consumption and material consumption of subsequent rectification separation.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic view of an evaporative mixer according to the present invention;

FIG. 2 is a process flow diagram of a methylamine production system of the present invention.

In the figure: 1-an evaporative mixer; 10-a horizontal housing; 11-a steam evaporator; 12-product heat exchanger; 111-a heating tube bundle; 121-a heat exchange tube bundle; 112-steam feeding and discharging end sockets; 122-product feeding and discharging end socket; 13-a mixing chamber; 14-an evaporation chamber; 141-a demister;

a 2-methylamine reactor; 20-a catalytic unit; 21-equilibrium catalyst layer; 22-a molecular sieve catalyst layer;

3-circulating the material tank; 31-circulating material feed pump;

4-a methanol feed tank; 41-methanol feed pump;

5-a steam heater; 6-raw material preheater; 7-electric heater.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the utility model, as claimed, but is merely representative of selected embodiments of the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element to which the description refers must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical", "overhang" and the like do not imply that the components are required to be absolutely horizontal or overhang, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Some embodiments of the utility model are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.

First embodiment

Referring to fig. 1, the evaporative mixer 1 provided in this embodiment includes: the horizontal type shell 10 is internally and oppositely provided with a steam evaporator 11 and a product heat exchanger 12;

the steam evaporator 11 comprises a heating tube bundle 111 and a steam feed and discharge head 112, and the product heat exchanger 12 comprises a heat exchange tube bundle 121 and a product feed and discharge head 122;

the methylamine product enters the horizontal housing 10 to recover heat from the methylamine product.

The evaporation mixer 1 of the utility model mainly mixes and evaporates the synthetic raw materials of methylamine, so that the fed methanol, liquid ammonia and circulating materials are evaporated and mixed in the evaporation mixer 1, and then the mixture is further heated and enters the methylamine reactor 2 for reaction.

The steam evaporator 11 and the product heat exchanger 12 are integrated on the horizontal shell 10 of the evaporation mixer 1 to form the double-heat-source pool-type evaporation mixer 1, so that methanol, liquid ammonia and circulating materials can be vaporized and evaporated in the same pool-type evaporation mixer 1, the equipment number of an evaporation system is reduced, the flows of raw materials in feeding and gasification are simplified, and the equipment investment cost is reduced.

The double heat source heat exchanger formed by the steam evaporator 11 and the product heat exchanger 12 which are oppositely arranged can recover reaction heat generated in the synthesis of the methylamine product in the pool type evaporation mixer 1 on the basis of the existing steam heating evaporation.

The steam evaporator 11 and the product heat exchanger 12 respectively include a heating tube bundle 111 and a heat exchange tube bundle 121 which are arranged inside the horizontal shell 10, steam enters the heating tube bundle 111 through the steam inlet and outlet end socket 112, and methylamine products enter the heat exchange tube bundle 121 through the product inlet and outlet end socket 122, so that the raw materials in the horizontal shell 10 of the evaporation mixer 1 are heated through the steam and the methylamine products carrying a large amount of reaction heat.

The steam inlet and outlet seal head 112 is provided with a steam inlet and a steam outlet, steam enters the heating tube bundle 111 from the steam inlet through the steam inlet and outlet seal head 112, and is converted into steam condensate after heating and evaporating the raw material in the horizontal shell 10 in the heating tube bundle 111, and the steam condensate is discharged from the steam evaporator 11 through the steam outlet.

The product inlet and outlet end enclosure 122 is provided with a product inlet and a product outlet, methylamine products return to the product heat exchanger 12 after being generated in the methylamine reactor 2, enter the heat exchange tube bundle 121 from the product inlet through the product inlet and outlet end enclosure 122, are discharged from the product heat exchanger 12 through the product outlet after heat exchange and evaporation are carried out on raw materials in the horizontal shell 10 in the heat exchange tube bundle 121, enter a downstream separation device for further treatment, and the methylamine products transfer reaction heat carried by the methylamine products to the raw materials in a heat exchange process in a heat conduction mode, and carry out evaporation and heat exchange on the raw materials while being cooled.

By passing the methylamine product through the heat exchange tube bundle 121 in the horizontal shell 10, a large amount of reaction heat released during the synthesis of methylamine is effectively recycled, and the energy consumption loss is reduced. Through the form of integrating the heater on horizontal casing 10, effectively reduced the equipment quantity and the whole equipment height of evaporation hybrid system, reduced conveying equipment's consumption to the equipment area of evaporation hybrid system has been reduced, the installation at the scene is do benefit to more.

Specifically, the raw material in the present embodiment is mixed and heated in the mixing chamber 13 in the horizontal shell 10, the heating tube bundle 111 and the heat exchange tube bundle 121 are both disposed in the mixing chamber 13, and preferably, the heating tube bundle 111 and the heat exchange tube bundle 121 are disposed below the liquid level of the mixed raw material. Through this kind of mode of setting, can make the heat in steam and the methylamine product fully shift to the liquid raw materials in, improved the evaporation efficiency of raw materials.

The steam evaporator 11 and the product heat exchanger 12 both include a single-ended head, that is, the steam inlet/outlet head 112 and the product inlet/outlet head 122 are both one and respectively disposed at two ends of the horizontal housing 10. Through connecting the tube bank on the closing head to make the outside pipeline connection who carries steam and product on the closing head, be favorable to the installation of equipment and pipeline, and make steam or product pass in and out from the tube bank through same end head, can be favorable to prolonging flow path, guarantee in mixing chamber 13 with the heat transfer effect of raw materials.

Heating tube bank 111 and heat exchange tube bank 121 among steam evaporator 11 and product heat exchanger 12 in this embodiment are U type tube bank, and through the form of U type tube bank, do benefit to flowing medium and go out on single-ended head on the one hand, on the other hand still can reduce the leakage risk of material in hybrid chamber 13, make heating medium and raw materials medium effectively keep apart to avoid causing the influence to the methylamine synthesis reaction.

In the heating process of the mixing chamber 13, liquid raw materials such as methanol, liquid ammonia and recycled materials are very easy to cause entrainment of bubbles to the evaporated gas due to boiling of the liquid due to low boiling point, and particularly for the recycled materials, bubbles generated by boiling of the recycled materials may even have other solid impurities.

From this point of view, the horizontal housing 10 further comprises an evaporation chamber 14 located at the top of the mixing chamber 13, the evaporation chamber 14 communicating with the mixing chamber 13. A demister 141 for defoaming the evaporation gas raw material is installed in the evaporation chamber 14. The pressure of the evaporation gas can be effectively buffered in the evaporation chamber 14, different raw material gases can be preliminarily mixed in the evaporation chamber 14, the cleanliness of the evaporation gas can be ensured through the demister 141, and the blockage of a catalyst bed layer in the methylamine reactor 2 during reaction is avoided.

Through the evaporation mixer 1, the methylamine product after raw material synthesis can be effectively subjected to heat exchange in the product heat exchanger 12, and the liquid raw material in the evaporation mixer 1 is heated, so that a large amount of reaction heat generated in the synthesis reaction is recycled and comprehensively utilized, the whole reaction energy consumption is greatly reduced, and the production cost of unit product is effectively reduced.

Second embodiment

With reference to fig. 2, the present invention further provides a methylamine synthesis apparatus comprising the evaporation mixer 1, wherein the methylamine synthesis raw material in the evaporation mixer 1 is heated and evaporated, then heated and heated to further raise the temperature of the raw material, and then introduced into the methylamine reactor 2 for synthesis reaction.

A plurality of sections of catalytic units 20 distributed at intervals are arranged in the methylamine synthesizer, and each section of catalytic unit 20 comprises an equilibrium type catalyst layer 21 and at least one molecular sieve catalyst layer 22.

The existing gas-phase catalytic reaction of methanol and ammonia is mainly used for producing dimethylamine raw material which is required by the market in large quantity and is suitable for producing DMF (dimethyl formamide), but the method has low yield of the dimethylamine and has higher energy consumption and material consumption for reaching the target capacity.

In this synthesis, the gas phase catalytic reaction of methanol and ammonia is exothermic and can be carried out at 360-425 ℃ in the presence of a catalyst.

In addition to the reaction of methanol with ammonia to form monomethylamine, dimethylamine and trimethylamine, the following reactions are carried out in the methylamine reactor 2:

CH₃OH+CH₃NH₂→(CH₃)₂NH+H₂O+Q

(CH₃)₃N+NH₃→2(CH₃)₂NH-Q

2CH₃NH₂→(CH₃)₂NH+NH₃+Q

2(CH₃)₂NH→CH₃NH₂+(CH₃)₃NH+Q

in actual production, the synthesis is performed by using an equilibrium catalyst for the different reactions, the product distribution is a thermodynamic equilibrium value, and when the ratio of ammonia to methanol is 2: 1, the molar composition of monomethylamine, dimethylamine and trimethylamine is 27: 23: 50, the proportion of trimethylamine in the product is close to half, and although the yield of dimethylamine can be improved to some extent by increasing the reaction temperature, increasing the proportion of ammonia and methanol in the feed, and further reacting the trimethylamine feed back, a rectification separation system is usually required to enhance the separation, and the energy consumption and the material consumption of the system are undoubtedly increased.

By arranging the equilibrium catalyst layer 21 and the at least one molecular sieve catalyst layer 22 in the methylamine reactor 2, dimethylamine can reach equilibrium concentration under the action of an equilibrium catalyst, and then trimethylamine adsorbed by the molecular sieve catalyst layer 22 continuously reacts with ammonia, and the dimethylamine and monomethylamine continuously move to a lower layer to reach a non-equilibrium state after passing through the molecular sieve catalyst layer 22, so that the trimethylamine and ammonia further react to generate dimethylamine by converting the equilibrium reaction state into the non-equilibrium reaction state, and the aim of improving the conversion rate of the dimethylamine is fulfilled. The final dimethylamine formation is much higher than the equilibrium concentration and is a desired result for industrial production.

The methylamine synthesis apparatus in this embodiment further includes a reheating unit for reheating the raw material evaporated in the evaporation mixer 1, so as to raise the temperature of the reaction raw material gas and introduce the reaction raw material gas into the methylamine reactor 2.

The reheating unit comprises a steam heater 5, a raw material preheater 6 and an electric heater 7 which are sequentially connected through pipelines, wherein a feed inlet of the steam heater 5 is connected with a discharge outlet of the evaporation mixer 1, and a discharge outlet of the electric heater 7 is connected with a feed inlet of the methylamine reactor 2. The reheating unit is specifically used for further heating the evaporated and gasified gas raw materials to reach the temperature required by the reaction and then enter the methylamine reactor 2, and the reheating unit can gradually increase the temperature of the gasified gas to ensure the normal operation of the gas raw materials in the methylamine reactor 2.

Specifically, the evaporated and mixed gas raw material firstly enters the tube side of a steam heater 5, the gas raw material in the tube side is heated by steam in the shell side of the steam heater 5 and then enters the tube side of a raw material preheater 6, and then enters an electric heater to finally reach the temperature required by the reaction and then enters a methylamine reactor 2.

It should be noted that the methylamine product generated in the methylamine reactor 2 is primarily cooled and heat exchanged by the raw material preheater 6 and then enters the product heat exchanger 12 in the evaporation mixer 1. The raw material preheater 6 is used as a heat exchanger for preheating the raw material gas, and also used for further exchanging heat and raising the temperature of the gas raw material heated by the steam heater 5 through the reaction heat carried by the methylamine product.

The raw material preheater 6 specifically comprises a shell side inlet and a shell side outlet, the shell side inlet is connected with a discharge port of the methylamine reactor 2, and the shell side outlet is connected with a feed port of the product heat exchanger 12. Through this kind of mode of setting, can make the methylamine product let in raw materials pre-heater 6's casing to carry out the heat transfer to the gaseous raw materials in the 6 tube passes of raw materials pre-heater, thereby further improved the rate of recovery of reaction heat, guaranteed gaseous raw materials's intensification effect simultaneously.

In order to ensure the normal supply of reaction raw materials, a circulation material tank 3 and a methanol raw material tank 4 are arranged at the upstream of the evaporation mixer 1, a circulation material feeding pump 31 and a methanol feeding pump 41 are respectively arranged at the bottoms of the circulation material tank 3 and the methanol raw material tank 4, and the circulation material and the methanol are respectively introduced into a mixing chamber 13 in the evaporation mixer 1 through the circulation material feeding pump 31 and the methanol feeding pump 41.

Based on the conversion of trimethylamine into dimethylamine in the methylamine reactor 2 and the supply amount required to avoid vaporizing ammonia in the mixer 1 to avoid a normal reaction. The methylamine synthesis device in the embodiment further comprises an ammonia gas feeding pipe, wherein ammonia gas feeding holes are formed in the evaporation mixer 1 and the methylamine reactor 2 respectively, and ammonia gas is introduced into the evaporation mixer 1 and the methylamine reactor 2 through the ammonia gas feeding holes respectively. Through the ammonia inlet pipe that sets up, can guarantee the excess state of ammonia raw materials and in methylamine reactor 2 to do benefit to the synthesis that promotes methylamine, guarantee the reaction effect.

The methylamine synthesis device can effectively reduce the energy consumption of the whole reaction process, reduce the separation load by improving the conversion rate of dimethylamine, and provide necessary conditions for energy conservation and consumption reduction of a downstream rectification separation system.

The devices of the methylamine synthesis device are connected through pipelines, specifically, a raw material circulating material pipeline is connected with a circulating material tank 3, the circulating material tank 3 is connected with a circulating material pump through a pipeline, and the circulating material pump is connected with an evaporation mixer 1 through a pipeline.

Raw materials methyl alcohol pipeline and methyl alcohol head tank 4 are connected, and methyl alcohol head tank 4 passes through the pipe connection with methyl alcohol raw material pump, and methyl alcohol raw material pump passes through the pipe connection with evaporation mixer 1.

Evaporation mixer 1 passes through the pipeline and is connected with steam heater 5, steam heater 5 passes through the pipeline and is connected with raw materials pre-heater 6, the import of 6 shell sides of raw materials pre-heater passes through the pipeline and is connected with 2 discharge gates of methylamine reactor, the shell side export of raw materials pre-heater 6 is connected with the product heat exchanger 12 of evaporation mixer 1, through letting in the shell side of raw materials pre-heater 6 with the methylamine product, can effectively heat the gas raw materials in the 6 tube side of raw materials pre-heater, the reaction heat that carries the methylamine product is retrieved tentatively.

Through being connected the shell side export of raw materials pre-heater 6 with the product heat exchanger 12 of evaporation mixer 1, can make the methylamine product let in the heat exchanger tube bank 121 of product heat exchanger 12 after preliminary heat transfer to heat the liquid raw materials in the mixing chamber 13 of evaporation mixer 1.

The heat exchange tube bundle 121 at the bottom of the evaporation mixer 1 is connected to a downstream separation system by a pipeline, and further separation is carried out on the mixed methylamine product.

The raw material liquid ammonia and the raw material gas ammonia are respectively connected with the evaporation mixer 1 through pipelines, and the heating tube bundle 111 of the steam evaporator 11 is respectively connected with an external steam supply pipeline and a steam condensate pipeline for leading out steam condensate.

The methylamine reactor 2 is composed of a vertical tower or a vertical container and internal parts, wherein the internal parts comprise three gas distributors and catalyst supporting pieces, and the three gas distributors are respectively arranged at the upper part of each section of catalytic unit 20. The catalyst support members include three, which support the three-stage catalytic units 20, respectively.

Each catalyst support is provided with two layers of catalysts, including an arrangement of equilibrium type methylamine reaction catalysts and molecular sieve catalysts, and three sections of six layers of catalysts at intervals are arranged in the methylamine reactor 2.

The methylamine synthesis device mainly comprises the following steps in work:

1) the mixed monomethylamine, trimethylamine, recombinant components and the like stored in the circulating material tank 3 are pressurized by a circulating material pump and are sent into the evaporation mixer 1 through a pipeline;

2) pressurizing the methanol stored in the liquid methanol tank by a methanol raw material pump to send the methanol into an evaporation mixer 1;

3) liquid ammonia is sent into the evaporation mixer 1 through a pipeline, and gas ammonia liquid ammonia is sent into the evaporation mixer 1 through a pipeline;

4) the liquid methanol, the liquid circulating material and the liquid ammonia are mixed and evaporated in the evaporation mixer 1, and simultaneously, the gas ammonia is also sent into the evaporation mixer 1 through a pipeline;

5) the heat source of the evaporation mixer 1 comprises two types, one type is high-temperature gas at the outlet of the methylamine reactor 2 after primary heat exchange by the raw material preheater 6, and the other type is externally supplied high-temperature steam.

6) The mixed gas of the mixture in the evaporation mixer 1 after evaporation firstly passes through the steam heater 5 for preliminary heating up, then is sent into the raw material preheater 6 through the pipeline and exchanges heat with the high-temperature product gas at the outlet of the methylamine reactor 2 again, enters the electric heater 7 through the pipeline and is heated to 360 ℃ to enter the methylamine reactor 2, and fully reacts in the methylamine reactor 2 to generate the mixed methylamine gas.

7) The temperature of the generated mixed methylamine gas is about 425 ℃, the mixed methylamine gas enters the raw material preheater 6 through a pipeline to preheat the raw material, the mixed methylamine gas coming out of the raw material preheater 6 enters the heat exchange tube bundle 121 of the product heat exchanger 12 of the evaporation mixer 1 to heat and evaporate the material, and the mixed methylamine gas coming out of the heat exchange tube bundle 121 is sent to downstream rectification and separation.

8) The externally supplied high-temperature steam is sent into a heating tube bundle 111 of the evaporation mixer 1 through a pipeline to heat and evaporate the material, and the steam condensate is sent out of the methylamine synthesis device through a pipeline.

In one particular example of this, the first and second,

feeding the circulating material at about 40 ℃ into a circulating material tank, and feeding the circulating material into an evaporation mixer through a circulating material pump; feeding raw material methanol with the temperature of about 25 ℃ into a methanol raw material tank, and feeding the raw material methanol into an evaporation mixer through a pipeline by a methanol raw material pump; liquid ammonia is sent into the evaporation mixer through a pipeline, and the three materials are mixed and evaporated in the evaporation mixer.

The mixed gas of evaporation gets into steam heater through the pipeline after the demister removes the foam, and the mixed gas preheats to about 170 ℃, and the mixed gas reentrants raw materials pre-heater carries out the heat transfer with methylamine reactor export gas, and the mixed gas preheats to about 360 ℃, gets into electric heater, and normal condition electric heating is out of work, and the heat is supplemented with the electric heating when not enough. The method comprises the following steps of enabling a mixed gas at 360 ℃ to enter a methylamine reactor, enabling all substances in the methylamine reactor to generate a chemical reaction to generate a mixed methylamine gas, enabling the reaction to be an exothermic reaction, enabling the temperature of the mixed methylamine gas after the reaction to reach about 430 ℃, enabling the high-temperature methylamine mixed gas at the outlet of the methylamine reactor to enter a raw material preheater to exchange heat with the evaporated mixed gas to reach about 200 ℃, enabling the high-temperature methylamine mixed gas to enter a heat exchange tube bundle at the bottom of an evaporation mixer to be used for evaporating raw materials, enabling the mixed methylamine coming out of the heat exchange tube bundle to have a temperature of about 140 ℃, and enabling the mixed methylamine gas to enter a downstream rectification separation process.

The steam enters a heating tube bundle at the bottom of the evaporation mixer through a pipeline and exchanges heat with the raw material to supplement the heat of evaporation.

The unit methylamine product of the example can save 1.05t of steam/mixed methylamine, the dimethylamine content of the mixed methylamine can reach about 45 percent, and the energy consumption of the subsequent rectification is greatly reduced.

It is important to point out that the methylamine product in the methylamine reactor is introduced into the raw material preheater and the heat exchange tube bundle in the evaporation mixer, so that the reaction heat of the synthesis reaction can be recycled to the maximum extent, thereby being beneficial to reducing the energy consumption of the methylamine unit product, improving the conversion rate of dimethylamine by combining the molecular sieve catalyst, reducing the energy consumption and the power consumption of downstream rectification separation, and greatly improving the product competitiveness.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An evaporative mixer, comprising: the horizontal shell is provided with a horizontal shell,

2. The evaporative mixer of claim 1, wherein the horizontal housing includes a mixing chamber for mixed heating of the feedstock, the heating tube bundle and the heat exchanger tube bundle both being disposed in the mixing chamber.

3. The evaporative mixer of claim 2, wherein the steam feed and discharge head and the product feed and discharge head are each one and are disposed at each end of the horizontal housing.

4. The evaporative mixer of claim 2, wherein the heating tube bundle and the heat exchange tube bundle are U-shaped tube bundles.

5. The evaporative mixer of claim 4, wherein the horizontal housing further comprises an evaporation chamber at the top of the mixing chamber, the evaporation chamber being in communication with the mixing chamber, the evaporation chamber having a demister mounted therein for defoaming evaporated gases.

6. A methylamine synthesis device, which is characterized in that the device comprises the evaporation mixer of any one of claims 1-5, methylamine synthesis raw materials in the evaporation mixer are reheated and then enter a methylamine reactor for synthesis reaction, a plurality of sections of catalytic units are arranged in the methylamine reactor, and each section of catalytic unit comprises at least one molecular sieve catalyst layer.

7. The methylamine synthesis apparatus according to claim 6, further comprising a reheating unit for reheating, wherein the reheating unit comprises a steam heater, a raw material preheater and an electric heater which are arranged in sequence, a feed inlet of the steam heater is connected with a discharge outlet of the evaporation mixer, and a discharge outlet of the electric heater is connected with a feed inlet of the methylamine reactor.

8. The methylamine synthesis apparatus of claim 7, wherein the feedstock preheater comprises a shell-side inlet and a shell-side outlet, the shell-side inlet being connected to the outlet of the methylamine reactor, and the shell-side outlet being connected to the inlet of the product heat exchanger.

9. A methylamine synthesis apparatus according to claim 6, wherein a recycle material tank and a methanol feed tank are provided upstream of the evaporative mixer, and recycle material and methanol are fed into the evaporative mixer by a recycle material feed pump and a methanol feed pump respectively.

10. The methylamine synthesis apparatus according to claim 6, further comprising an ammonia gas inlet pipe, wherein the evaporation mixer and the methylamine reactor are respectively provided with an ammonia gas inlet, and ammonia gas is introduced into the evaporation mixer and the methylamine reactor through the ammonia gas inlet.