Reaction vessel and reaction system and method of using the reaction system

Abstract

The present application relates to the technical field of chemical reaction equipment, and discloses a reaction kettle, a reaction system and a use method of the reaction system. The present application comprises a reaction kettle and a pressure relief unit. The reaction kettle comprises a conical funnel structure and a gas phase balance pipe, which can effectively solve the problems of long heating and cooling time and serious material accumulation at the bottom of the existing high-temperature and high-pressure large reaction kettle. The pressure relief unit comprises a condensation buffer tank, a tail gas condenser, a condensate receiving tank, a tail gas treatment module and a circulating pump, which can solve the problem of instantaneous VOC emission exceeding the standard and failing to meet the environmental protection requirements when the high-temperature and high-pressure reaction system is relieved. The present application has simple process, low investment cost and low energy consumption, and is very suitable for the preparation process of high-temperature and high-pressure catalysts prone to wall sticking.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical reaction equipment, in particular to a reaction kettle, a reaction system and a method for using the reaction system. BACKGROUND

[0002] The kettle type reaction kettle is a cylindrical reaction kettle with low height-diameter ratio, which is used to realize liquid single-phase reaction process and liquid-liquid, gas-liquid, liquid-solid, gas-liquid-solid and other multiphase reaction processes. The inside of the device is often provided with a stirring (mechanical stirring, air flow stirring, etc.) device. When the height-diameter ratio is large, multiple stirring blades can be used. When the material needs to be heated or cooled during the reaction process, a jacket can be arranged at the wall of the reaction kettle, or a heat exchange surface can be arranged in the device, or heat exchange can be performed through external circulation.

[0003] There are many documents and reports about traditional stirred tank reaction kettles, and the equipment design and manufacturing have been basically mature, but many problems still occur in actual scale-up production process. For example, when the reaction material is in a solid-liquid slurry state and has a large viscosity, due to the limitations of stirring and the influence of large size of the reaction kettle, the material in the reaction kettle will deposit in the kettle, and the material will accumulate and the discharge will not be smooth during discharge, thereby causing uneven mixing of the material, slow reaction rate, and decrease of conversion rate and selectivity, and even causing the consequence of seizure of the stirring shaft, which will have a great impact on the normal operation of the device. However, this phenomenon cannot be fully manifested in small-scale laboratory devices.

[0004] If the reaction pressure is normal pressure or slightly positive pressure, the bottom head of the reaction kettle can be directly changed into a conical shape to solve the problem, but under high temperature and high pressure conditions, the conical head cannot withstand very high pressure due to stress limitations. If a wall-scraping stirring blade is used, although it can temporarily solve the problem of material accumulation in the kettle, the stirring effect is greatly reduced, thereby affecting the reaction effect, and in addition, the wall-scraping blade will increase the stirring power due to increased resistance.

[0005] CN103130945A discloses a PMMA continuous production process without material accumulation for long-term operation, which adopts a down-in and up-out polymerization kettle and a stirring and heating kettle. The kettle is designed with a spiral belt stirrer, an internal plating or polishing treatment, and a small amount of inert solvent is added to the reaction mixture to increase the fluidity of the mixture system. A circulating loop is added between the distillation column reboiler and the waste liquid tank to add a polymerization inhibitor Degussa to avoid the problem of polymer accumulation in the container and pipeline during PMMA continuous bulk polymerization, and to ensure long-term continuous and stable operation of the production. However, this method requires the addition of new substances to prevent polymerization and increase fluidity, which has a certain specificity for reaction materials.

[0006] CN1335199A discloses a solid-liquid two-phase full-mixing reaction method, especially for solid-liquid two-phase full-mixing reaction method with large difference in specific gravity. The invention uses a specially designed wall scraping stirrer to achieve good back-mixing effect at low speed, greatly improving the reaction conversion rate and selectivity. This technology overcomes the shortcomings of the prior art that cannot achieve ideal stirring effect in industrial scale-up, making this type of reaction suitable for industrial application. However, the stirring speed of this wall scraping stirrer is generally not very high, which is not suitable for systems with high mixing requirements.

[0007] Chinese patent application 201620201887.5 discloses a stirring tank for producing petrochemical products. The stirring tank body is provided with a stirring device on the upper part. The stirring device is linked to the variable speed box on the upper end of the stirring tank body. The variable speed box is installed with a stirring motor. The upper end of the stirring tank body is provided with a booster pump on one side. The outer wall is provided with a heat preservation device. The lower end of the stirring tank body is provided with a discharge chamber. The discharge chamber is provided with an inclined installed discharge shaft. The discharge shaft is provided with a pushing screw blade on the high end. The low end of the discharge shaft is installed on the second variable speed box. The low end of the discharge shaft is provided with airtight door. However, the device has relatively more internal equipment, which is not suitable for high pressure system reaction. SUMMARY

[0008] The purpose of the present application is to overcome the problems of solid deposition, wall hanging and poor discharge in the traditional solid-liquid two-phase or gas-solid-liquid three-phase stirring reaction tank in the prior art. The present application provides a reaction tank and a reaction system and a method for using the reaction system. The present application can avoid the problem of material accumulation at the bottom of the reaction tank, has the advantages of convenient discharge and flushing, simple process, low investment cost, low energy consumption and convenient operation.

[0009] In order to achieve the above purpose, the present application provides a reaction tank, which comprises a cylinder, an upper head with a feed inlet and a lower head with a discharge outlet sealingly connected to both ends of the cylinder, a conical hopper structure arranged in the lower head, the large end of the conical hopper structure being sealingly and fixedly connected to the bottom surface of the cylinder, and the small end of the conical hopper structure being sealingly and fixedly connected to the discharge outlet at the bottom of the lower head, so that the outer wall of the conical hopper structure and the part of the internal lower end of the reaction tank containing the lower head form a closed cavity.

[0010] At least one balance pipe is fixedly arranged on the wall surface of the cylinder, and each balance pipe communicates the cavity and the top gas phase space in the reaction tank, for balancing the pressure of the cavity and the internal part of the reaction tank.

[0011] Preferably, the included angle α between the generatrix of the conical hopper structure and the horizontal plane is 5-80°, more preferably 30-60°.

[0012] Preferably, each of the balance pipes is fixed at a distance of 25-600 mm from the inner wall of the reactor, preferably 50-300 mm.

[0013] Preferably, each of the balance pipes has a diameter of 6-100 mm.

[0014] Preferably, the top outlet of each of the balance pipes is higher than the liquid level of the reactor, and the upper end of each of the balance pipes is fixed to the wall of the reactor.

[0015] Preferably, the reactor further comprises a baffle and a stirrer.

[0016] Preferably, the baffle is arranged in the middle or lower part of the reactor to cause back mixing of the liquid phase after colliding with the baffle, and the stirrer is used to provide dynamic stirring conditions in the reactor.

[0017] Preferably, the inner wall of the reactor and / or the inner wall of the conical funnel structure is mirror polished and / or coated with an anti-sticking coating.

[0018] In another aspect, the present application provides a reaction system comprising a reactor and a pressure relief unit, wherein the reactor is the reactor as described in the present application.

[0019] Preferably, the pressure relief unit comprises a condensation buffer tank, a tail gas condenser, a condensate receiving tank, a tail gas treatment module, and a circulating pump, wherein,

[0020] the condensation buffer tank, the inlet of the condensation buffer tank being in communication with the gas phase outlet of the reactor, preferably a valve is arranged on the pipeline connecting the inlet of the condensation buffer tank with the gas phase outlet of the reactor;

[0021] the tail gas condenser, the inlet of the tail gas condenser being in communication with the gas phase outlet of the condensation buffer tank, preferably a throttling device is arranged on the pipeline connecting the inlet of the tail gas condenser with the gas phase outlet of the condensation buffer tank, preferably the throttling device comprises a flow restrictor and / or a regulating valve;

[0022] the condensate receiving tank, the top inlet of the condensate receiving tank being in communication with the liquid phase outlet of the tail gas condenser, and the bottom outlet being in communication with the outlet of the condensation buffer tank;

[0023] the tail gas treatment module, the inlet of the tail gas treatment module being in communication with the gas phase outlet of the tail gas condenser;

[0024] the circulating pump, the inlet of the circulating pump being in communication with the respective outlet of the condensation buffer tank and the condensate receiving tank, and the outlet of the circulating pump being in communication with the gas phase inlet of the reactor.

[0025] Preferably, the tail gas treatment module comprises one or more of an acid washing tower, an alkali washing tower, a water washing tower, and an incinerator.

[0026] Preferably, the tail gas condenser is configured to use circulating water and / or chilled water as the cooling medium, and is preferably configured to use chilled water as the cooling medium. The method for using the reaction system in the present application comprises the following steps:

[0027] a) adding the reaction material into the reaction kettle, starting the stirrer, and reacting under the reaction condition;

[0028] b) after the reaction is completed, opening the valve between the reaction kettle and the condensation buffer tank, and depressurizing and cooling the reaction system;

[0029] c) when the pressure of the reaction system is reduced to 0-0.5 MPag, opening the throttling device, discharging the gas in the reaction system to the tail gas condenser, and condensing the liquid into the condensate receiving tank, and condensing the gas into the tail gas treatment module;

[0030] d) after the depressurization is completed, operating the circulating pump to pump the condensed liquid recovered from the condensation buffer tank and the condensate receiving tank back to the reaction kettle as the raw material for the next kettle.

[0031] The present application adopts a conical plate structure and a balance pipe inside the reaction kettle, which can effectively solve the problems of easy material accumulation and poor discharging in the reaction kettle under high temperature and high pressure conditions. The depressurization unit and the depressurization method are connected to the reaction kettle, which can quickly reduce the pressure and temperature of the reaction kettle system, and further enter the tail gas treatment system through the throttling device, which can solve the technical problem that the instantaneous VOC emission exceeds the standard during the depressurization of the high temperature and high pressure reaction system, and cannot meet the environmental protection requirements. The present application has the advantages of simple device, convenient operation, low investment cost, low energy consumption, and is suitable for industrial scale-up application and device modification, and is suitable for the preparation process of catalysts which are prone to wall sticking under high temperature and high pressure.

[0032] Other features and advantages of the present application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 Structure schematic diagram of a reaction kettle according to an embodiment of the present application;

[0034] Figure 2 Structure schematic diagram of a conical funnel structure in the present application;

[0035] Figure 3 Flow schematic diagram of a reaction system according to an embodiment of the present application.

[0036] REFERENCE SIGNS

[0037] 1 reactor; 11 cylinder; 12 upper head; 13 lower head; 14 conical funnel structure; 15 cavity; 16 balance pipe; 19 baffle; 20 stirrer; 2 condensation buffer tank; 3 tail gas condenser; 4 tail gas treatment module; 5 condensate receiving tank; 6 circulating pump; 7 valve; 8 throttling device. DETAILED DESCRIPTION

[0038] The specific embodiments of the present application will be described in detail hereinafter with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and explanatory and are not intended to limit the present application.

[0039] The endpoints of the ranges and any values disclosed herein are not limited to the precise values stated. The endpoints of the ranges and any values are provided as approximate descriptions of the ranges and are understood to be open-ended. Each range disclosed herein is to be understood to include individual values, and sub-ranges, within the stated ranges. Unless otherwise stated, the endpoints of the ranges are not inclusive of the values.

[0040] In the present application, unless otherwise stated, the orientation words such as "upper", "lower", "left", "right" generally refer to the upper, lower, left and right shown in the drawings; "inner", "outer" refer to the inner, outer relative to the contour of each component itself.

[0041] As shown in Figures 1-3 The first aspect of the present application provides a reactor, comprising a cylinder 11 and an upper head 12 with a feed port and a lower head 13 with a discharge port sealingly connected to both ends of the cylinder 11, a conical funnel structure 14 is arranged in the lower head 13, the large end of the conical funnel structure 14 is sealingly and fixedly connected to the bottom surface of the cylinder 11, and the small end of the conical funnel structure 14 is fixedly and sealingly connected to the discharge port at the bottom of the lower head 13, so that the outer wall of the conical funnel structure 14 and the part of the inside of the reactor 1 including the lower end of the lower head 13 form a closed cavity 15.

[0042] At least one balance pipe 16 is fixedly arranged on the wall surface of the cylinder 11, and each balance pipe 16 communicates the cavity 15 and the top gas phase space inside the reactor 1, for balancing the pressure of the cavity 15 and the inside of the reactor 1.

[0043] As shown in Figure 1 According to a preferred embodiment of the present application, the included angle α between the generatrix of the conical funnel structure 14 and the horizontal plane is 5-80°, and more preferably 30-60°.

[0044] The key of the present application is that the traditional reaction kettle ellipsoidal or spherical lower head 13 is changed into a conical head shape through the conical funnel structure 14. The present application can avoid the material deposition and wall hanging phenomenon due to the existence of the stirring dead angle, especially when the reaction kettle 1 including the stirrer is larger in diameter, the smooth area of the discharge port at the bottom of the reaction kettle is more likely to accumulate material, and if the material viscosity is larger, the material may be caked, and after a long time, the discharge port may be blocked, causing the discharge to be difficult, and even the stirring may be dead in the reaction process. Once this situation occurs, it is difficult to timely relieve pressure under the condition of high temperature and high pressure, causing the loss of material and product. By using the present application, the stirring dead angle existing at the bottom of the enlarged reaction kettle 1 can be reduced and avoided, and the material will not be accumulated during stirring. Since the discharge and flushing are easier due to the existence of a certain slope at a certain angle a with the horizontal plane.

[0045] It is worth noting that since the closed cavity 15 formed by the conical funnel structure 14 and the inner wall and lower head 13 of the reaction kettle 1 expands due to heat, it is easy to cause damage to the equipment, and therefore the closed cavity 15 is preferably connected to the gas phase space of the reaction kettle 1 through the gas phase balance pipe 16 to maintain the gas phase balance. In addition, the angle a is preferably 30°-60°, and if the angle is too small, the effect is not obvious, and if the angle is too large, the heating area of the jacket will be damaged.

[0046] At the same time, in order to completely solve the problem of material accumulation, an upper or lower expansion kettle bottom valve can also be used at the bottom of the reaction kettle 1, the valve root of the valve is at the same horizontal plane as the kettle bottom, and the traditional valve has a dead angle of a pipeline, which is easy to cause solid material blockage. In addition, a spraying device can also be used at the top of the reaction kettle, and the spraying holes are directed to the kettle wall, the conical funnel structure and the kettle bottom valve. After the discharge is completed, the flushing is carried out to prevent the residual slurry from caking.

[0047] As shown in Figure 2 According to a preferred embodiment of the present application, the conical funnel structure 14 is an annular support plate, the large end of which is seamlessly welded together with the cylinder body 11 or the lower head 13 or the connecting line of the cylinder body 11 and the lower head 13, the small end of which is seamlessly welded together with the discharge port of the lower head 13 or inside the lower head 13, and the small end outlet surrounds the discharge port of the lower head, so that the material flows through the conical funnel structure 14 and is discharged through the discharge port of the lower head.

[0048] According to a preferred embodiment of the present application, each balance pipe 16 is fixedly arranged at a distance of 25-600 mm from the inner wall 25 of the reaction kettle 1, preferably 50-300 mm.

[0049] According to a preferred embodiment of the present application, the inner diameter of each balance pipe 16 is 6-100 mm.

[0050] According to a preferred embodiment of the present application, the outlet of the balance pipe 16 is higher than the liquid level of the reactor, and the upper end of the balance pipe is fixed to the wall of the reactor 1.

[0051] As shown in Fig. 1, according to a preferred embodiment of the present application, the reactor 1 further comprises a baffle 19 and a stirrer 20; wherein the baffle 19 is arranged in the middle and lower part of the reactor 1, so as to make the liquid phase of the reactor 1 return and mix after colliding with the baffle, and the stirrer 20 is used to provide dynamic stirring conditions for the reactor 1. Figure 1

[0052] According to a preferred embodiment of the present application, the inner wall of the reactor 1 and / or the inner wall of the conical funnel structure 14 is polished and mirror-finished and / or coated with an anti-sticking coating.

[0053] As shown in Fig. 1, according to a preferred embodiment of the present application, the reactor 1 further comprises a baffle 19 and a stirrer 20; wherein the baffle 19 is arranged in the middle and lower part of the reactor 1, so as to make the liquid phase of the reactor 1 return and mix after colliding with the baffle, and the stirrer 20 is used to provide dynamic stirring conditions for the reactor 1. Figure 3

[0054] According to a preferred embodiment of the present application, the pressure relief unit comprises a condensation buffer tank 2, a tail gas condenser 3, a condensate receiving tank 5, a tail gas treatment module 4 and a circulating pump 6; wherein the condensation buffer tank 2 is connected to the gas phase outlet of the reactor 1, and a valve 7 is preferably arranged on the pipeline connecting the condensation buffer tank 2 to the gas phase outlet of the reactor 1; the tail gas condenser 3 is connected to the gas phase outlet of the condensation buffer tank 2, and a throttling device 8 is preferably arranged on the pipeline connecting the tail gas condenser 3 to the gas phase outlet of the condensation buffer tank 2, and the throttling device 8 preferably comprises a flow limiting orifice and / or a regulating valve; the condensate receiving tank 5 is connected to the liquid phase outlet of the tail gas condenser 3 at the top and to the outlet of the condensation buffer tank 2 at the bottom; the tail gas treatment module 4 is connected to the gas phase outlet of the tail gas condenser 3; and the circulating pump 6 is connected to the outlets of the condensation buffer tank 2 and the condensate receiving tank 5 respectively, and the outlet of the circulating pump 6 is connected to the gas phase inlet of the reactor 1.

[0055] Various pipelines or valves and components that may be required in the industry can be added to each part as required, and the present application does not have any special requirements in this regard, which will not be described in detail herein.

[0056] ​​In the prior art, when the reaction kettle is depressurized, either the depressurization time is too long, affecting the production capacity, or the instantaneous gas flow is too large, which cannot be processed in time, causing environmental protection to be substandard, and even leading to the shutdown of the device. The present application can quickly depressurize and cool down through pressure balance, because the pressure of the system is mainly formed by the saturated steam pressure of the reaction material, and the pressure decreases, causing the temperature to decrease; when the pressure decreases, the valve is opened, and the exhaust gas enters the exhaust gas treatment module through the throttling device 8 for treatment, which can not only reduce the depressurization time, but also ensure that the released gas meets the standard. The present application can be applied to industrial production, and is especially suitable for the preparation process of catalysts.

[0057] The present application can effectively solve the problems of long heating and cooling time of existing high-temperature and high-pressure large reaction kettles, serious material accumulation at the bottom, and too large instantaneous value of tail gas leading to substandard VOC, and can be applied to industrial production, and is especially suitable for the preparation process of catalysts.

[0058] According to a preferred embodiment of the present application, the exhaust gas treatment module 4 comprises one or more of an acid washing tower, an alkali washing tower, a water washing tower and an incinerator.

[0059] According to a preferred embodiment of the present application, the exhaust gas condenser 3 is arranged to be able to use circulating water and / or chilled water as a cooling medium, and is preferably arranged to be able to use chilled water as a cooling medium.

[0060] As shown in Figure 1 the use method of the reaction system in the present application comprises the following steps:

[0061] a) adding the reaction material into the reaction kettle 1, starting the stirrer, and reacting under the reaction condition;

[0062] b) after the reaction is completed, opening the valve 7 between the reaction kettle 1 and the condensation buffer tank 2, and depressurizing and cooling the reaction system;

[0063] c) when the pressure of the reaction system decreases to 0-0.5 MPag, opening the throttling device 8, discharging the gas of the reaction system to the exhaust gas condenser 3, the condensed liquid entering the condensate receiving tank 5, and the condensed gas entering the exhaust gas treatment module 4;

[0064] d) after the depressurization is completed, operating the circulating pump 6 to pump the condensed liquid recovered from the condensation buffer tank 2 and the condensate receiving tank 5 back to the reaction kettle as the raw material for the next kettle;

[0065] According to a preferred embodiment of the operation method of the reaction system of the present application, the operation method is as follows:

[0066] 1) The reaction material is added to the high-temperature and high-pressure reaction kettle 1, the stirrer is turned on, the inlet and outlet valves of the reaction kettle are closed, the heating medium is introduced into the jacket of the reaction kettle to heat it, and the temperature, pressure and reaction time of the reaction kettle are controlled;

[0067] 2) After the reaction is completed, the heating medium is stopped, the pressure relief unit is opened, the cooling medium of the condenser in the condensation buffer tank 2 is opened, the valve between the reaction kettle and the condensation buffer tank is opened, the reaction kettle is rapidly depressurized and cooled, the saturated gas in the reaction kettle is condensed by the condenser, and the temperature and pressure of the reaction system are further reduced;

[0068] 3) When the pressure of the reaction system is reduced to 0-0.5 MPag, the throttling device is opened, the gas in the reaction system is discharged to the tail gas condenser 3 at a certain flow rate, the condensed liquid enters the condensate receiving tank 5, and the condensed gas enters the tail gas treatment module 4;

[0069] 4) After the pressure relief is completed, the liquid in the condensation buffer tank 2 and the condensate receiving tank 5 is pumped back to the reaction kettle by the circulating pump 6 as the raw material for the next kettle.

[0070] According to a preferred embodiment of the operation method of the reaction system of the application, the reaction kettle in step 1) includes a cylinder 11, a head, a stirrer 20, a baffle 19, a conical funnel structure 14, and a balance pipe 16, which can be used in catalyst production.

[0071] According to a preferred embodiment of the operation method of the reaction system of the application, the reaction kettle is provided with a conical funnel structure 14 connected with the bottom head and the cylinder 11 of the reaction kettle, and the horizontal angle thereof is 5-80°, preferably 30-60°.

[0072] As shown in Figure 2 According to a preferred embodiment of the operation method of the reaction system of the application, the conical funnel structure 14 is an annular support plate.

[0073] According to a preferred embodiment of the operation method of the reaction system of the application, the conical funnel structure 14 is provided with a balance pipe 16, the bottom of the balance pipe is communicated with the conical funnel structure, the top of the balance pipe is communicated with the gas phase space of the top of the reaction kettle, the outlet of the top of the balance pipe is higher than the liquid level of the reaction kettle, and the upper end of the balance pipe is fixed to the kettle wall.

[0074] According to a preferred embodiment of the operation method of the reaction system of the application, the inner wall of the reaction kettle 1 and the conical funnel structure 14 are polished and mirror-finished and / or coated with an anti-sticking coating.

[0075] According to a preferred embodiment of the operation method of the reaction system of the application, the distance between the balance pipe 16 and the wall of the reaction kettle is 25-600 mm, preferably 50-300 mm.

[0076] According to a preferred embodiment of the method for operating a reaction system of the present application, the pressure relief unit of step 2) comprises a condensation buffer tank 2, a tail gas condenser 3, a condensate receiving tank 5, a tail gas treatment module 4 and a circulating pump 6.

[0077] According to a preferred embodiment of the method for operating a reaction system of the present application, the condensation buffer tank 2 is connected to the gas phase outlet of the reactor; the tail gas condenser 3 is connected to the gas phase outlet of the condensation buffer tank; the condensate receiving tank 5 is connected to the liquid phase outlet of the tail gas condenser at the top and to the condensation buffer tank at the bottom; the tail gas treatment module 4 is connected to the gas phase of the tail gas condenser; the circulating pump 6 is connected to the condensation buffer tank 2 and the condensate receiving tank 5 at the inlet and to the reactor 1 at the outlet.

[0078] According to a preferred embodiment of the method for operating a reaction system of the present application, the reactor 1 is connected to the condensation buffer tank 2 via a pipe with a valve 7 in the middle; a throttling device 8, preferably an orifice or a regulating valve, is arranged between the condensation buffer tank and the tail gas condenser.

[0079] According to a preferred embodiment of the method for operating a reaction system of the present application, the cooling medium of the tail gas condenser 3 is circulating water, more preferably chilled water.

[0080] According to a preferred embodiment of the method for operating a reaction system of the present application, the tail gas treatment module 4 is preferably one or more of an acid washing tower, an alkali washing tower, a water washing tower and an incinerator.

[0081] The present application is further illustrated by the following examples and comparative examples, but the present application is not limited to them.

[0082] The following examples are carried out using a reactor as shown in Figure 1 and a system as shown in Figure 3 The reactor comprises:

[0083] a cylinder 11, an upper head 12 with a feed port sealingly connected to both ends of the cylinder 11, and a lower head 13 with a discharge port, a conical funnel structure 14 is arranged in the lower head 13, the large end of the conical funnel structure 14 is sealingly and fixedly connected to the bottom surface of the cylinder 11, and the small end of the conical funnel structure 14 is fixedly and sealingly connected to the discharge port at the bottom of the lower head 13, so that the outer wall of the conical funnel structure 14 and the part of the inside of the reactor 1 below the lower end of the lower head 13 form a closed cavity 15.

[0084] A balance pipe 16 is fixedly arranged on the wall surface of the cylinder 11, the top outlet of the balance pipe 16 is higher than the liquid level of the reactor 1, and the upper end of the balance pipe 16 is fixed to the wall of the reactor 1.

[0085] A baffle 19 and a stirrer 20; wherein the baffle 19 is arranged at the middle and lower part of the reactor 1;

[0086] The inner wall of the reactor 1 and the inner wall of the conical funnel structure 14 are polished mirror surface treated;

[0087] The method comprises:

[0088] a) adding reactant into the reactor, starting the stirrer, and reacting under reaction conditions;

[0089] b) after the reaction is completed, opening the valve between the reactor and the condensation buffer tank, and depressurizing and cooling the reaction system;

[0090] c) when the pressure of the reaction system is reduced to 0-0.5 MPa, starting the throttling device, discharging the gas in the reaction system to the tail gas condenser, and condensing the liquid into the condensate receiving tank and the gas into the tail gas treatment module;

[0091] d) after the depressurization is completed, operating the circulating pump to pump the condensate recovered from the condensation buffer tank and the condensate receiving tank back to the reactor as raw material for the next reactor;

[0092] The tail gas treatment module selects one or more of an acid washing tower, an alkali washing tower, a water washing tower and an incinerator according to specific requirements;

[0093] The tail gas condenser 3 uses chilled water as a cooling medium.

[0094] Example 1

[0095] The stirring reactor 1 of the present application (such as Figure 1 ) is used to prepare a molecular sieve catalyst according to the process shown in Figure 3 , and the volume of the catalyst is 1 m 3 , the stirring speed of the stirrer 20 is 100 rpm, the included angle α between the generatrix of the conical funnel structure 14 and the horizontal plane is 30°, the balance pipe 16 is fixedly arranged at a distance of 80 mm from the inner wall of the reactor 1, and the inner diameter of the balance pipe 16 is 25 mm. Phosphoric acid 80 kg, aluminum sol 10 kg, sol 40 kg, organic amine 80 kg, additive 80 kg and pure water 200 kg are added into the reactor 1, and SAPO molecular sieve catalyst is prepared at 300℃ and 3.0 MPa(g), and the equipment size and parameters of the reactor 1 are shown in the attached Figure 1 Figure 3 . After the reaction is completed, the depressurization and cooling to 45℃ are performed according to the operation method of the depressurization unit of the present application, and the operation method comprises:

[0096] b) after the reaction is completed, opening the valve 7 between the reactor and the condensation buffer tank 2, and depressurizing and cooling the reaction system;

[0097] c) when the pressure of the reaction system drops to 0-0.5 MPag, the throttle device 8 is opened, and the gas in the reaction system is discharged at 200 kg / h to the tail gas condenser 3, the condensed liquid enters the condensate receiving tank 5, and the condensed gas enters the tail gas treatment module 4;

[0098] d) after the pressure relief is completed, the circulating pump 6 is operated to pump the condensed liquid recovered from the condensing buffer tank 2 and the condensate receiving tank 5 back to the reaction kettle as raw materials for the next kettle;

[0099] After the pressure relief of the reaction kettle is completed, the discharge port of the lower head is opened, the reaction kettle 1 is unloaded, and then the molecular sieve is sequentially subjected to pressure filtration, washing, and drying to obtain a molecular sieve product. Through analysis and evaluation, the selectivity of the molecular sieve is >85%, the yield of the molecular sieve is ≥90%, there is no accumulation phenomenon during the reaction process and unloading, the instantaneous value of VOC in the discharged gas is ≤50 ppm, and the environmental protection requirements are met.

[0100] Example 2

[0101] The implementation is the same as in Example 1, except that the balance pipe 16 is fixedly arranged at a distance of 400 mm from the inner wall of the reaction kettle 1. Since the balance pipe is located in the middle of the reaction kettle, it has a certain influence on the installation and operation of the stirring paddle.

[0102] Example 3

[0103] The implementation is the same as in Example 1, except that the angle a between the generatrix of the conical funnel structure 14 and the horizontal plane is 60°. There is no accumulation phenomenon during the reaction process and unloading, the instantaneous value of VOC in the discharged gas is ≤50 ppm, and the environmental protection requirements are met.

[0104] Example 4

[0105] The implementation is the same as in Example 1, except that the angle a between the generatrix of the conical funnel structure 14 and the horizontal plane is 45°. There is no accumulation phenomenon during the reaction process and unloading, the instantaneous value of VOC in the discharged gas is ≤50 ppm, and the environmental protection requirements are met.

[0106] Example 5

[0107] In Example 1, the other operating parameters remain unchanged, and the change is that the size of the reaction kettle 1 is Φ2600x5000 mm, with a volume of about 30 m 3 , the angle a is 70°, the selectivity of the obtained molecular sieve product is >80%, the yield of the molecular sieve is >85%, and there is no accumulation phenomenon during the reaction process and unloading. However, due to the large angle, the material in the reaction kettle is not uniformly mixed, which has a certain influence on the selectivity of the product.

[0108] Comparative Example 1

[0109] In Example 1, other operating parameters remain unchanged, and the change is that the size of the reactor 1 is Φ2600x5000mm, with a volume of about 30m 3 The reaction kettle is not provided with the conical funnel structure 14, and a traditional oval head structure is adopted, so that the selectivity of the molecular sieve product is greater than 83%, the yield of the molecular sieve is greater than 85%, but during the reaction process and discharging, the phenomenon of accumulated material and poor discharging occurs.

[0110] Comparative Example 2

[0111] Compared with the traditional method, that is, the gas of the crystallization kettle is directly connected to the gas phase inlet of the tail gas condenser 3, the exhaust valve is directly opened, and the gas of the crystallization kettle is discharged after being condensed by the tail gas condenser, at this time, the instantaneous value of VOC in the exhaust gas is more than 2000ppm, which exceeds the environmental protection requirement. In order to meet the environmental protection emission requirement, the exhaust gas port valve must be closed, thereby causing the discharge time to be prolonged by at least 2 times.

[0112] Comparative Example 3

[0113] The implementation is the same as Example 1, except that the balance pipe 16 is not provided, and the gas in the sealed cavity 15 formed by the conical funnel structure 14 and the lower head of the reaction kettle expands when heated, causing the conical funnel structure to deform and even crack.

[0114] The preferred embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, various possible combination manners are not described again in the present application. However, these simple modifications and combinations should also be regarded as the disclosed content of the present application, and all belong to the protection scope of the present application.

Claims

1. A reaction vessel comprising a cylinder (11) and an upper head (12) with a feed inlet and a lower head (13) with a discharge outlet sealingly connected to both ends of the cylinder (11), characterized in that, A conical funnel structure (14) is arranged in the lower head (13), the large end of the conical funnel structure (14) is sealingly and fixedly connected to the bottom surface of the cylinder (11), and the small end of the conical funnel structure (14) is sealingly and fixedly connected to the discharge port at the bottom of the lower head (13), so that the outer wall of the conical funnel structure (14) and the part of the inside lower end of the reactor (1) including the lower head (13) form a closed cavity (15); At least one balance pipe (16) is fixedly arranged on the wall surface of the cylinder (11), each balance pipe (16) is communicated with the cavity (15) and the top gas phase space in the reactor (1), and is used for balancing the pressure in the cavity (15) and the inside of the reactor (1); The included angle α between the generatrix of the conical funnel structure (14) and the horizontal plane is 5-80°.

2. The reactor of claim 1, wherein, The included angle α between the generatrix of the conical funnel structure (14) and the horizontal plane is 30-60°.

3. The reactor according to claim 1, wherein, Each balance pipe (16) is fixedly arranged at a distance of 25-600 mm from the inner wall of the reactor (1); and / or The inner diameter of each balance pipe (16) is 6-100 mm.

4. The reactor of claim 1, wherein, Each balance pipe (16) is fixedly arranged at a distance of 50-300 mm from the inner wall of the reactor (1).

5. The reactor according to claim 1, wherein, The top outlet of each balance pipe (16) is higher than the liquid level of the reactor (1), and the upper end of the balance pipe (16) is fixed to the wall of the reactor (1).

6. The reactor according to any one of claims 1-5, wherein, The reactor (1) further comprises a baffle (19) and a stirrer (20); The baffle (19) is arranged at the middle lower part of the reactor (1) and is used for making the liquid phase of the reactor (1) return and mix after colliding with the baffle (19), and the stirrer (20) is used for providing dynamic stirring conditions of the reactor (1); and / or The inner wall of the reactor (1) and / or the inner wall of the conical funnel structure (14) is subjected to mirror polishing and / or anti-sticking coating treatment.

7. A reaction system comprising a reaction vessel (1) and a pressure relief unit, characterized in that The reactor is the reactor (1) according to any one of claims 1-6.

8. The reaction system of claim 7, wherein, The pressure relief unit comprises a condensation buffer tank (2), a tail gas condenser (3), a condensate receiving tank (5), a tail gas treatment module (4) and a circulating pump (6), wherein, The condensation buffer tank (2) is communicated with the gas phase outlet of the reactor (1) through the inlet thereof; The tail gas condenser (3) is communicated with the gas phase outlet of the condensation buffer tank (2) through the inlet thereof; The condensate receiving tank (5) is communicated with the liquid phase outlet of the tail gas condenser (3) through the top inlet thereof and is communicated with the outlet of the condensation buffer tank (2) through the bottom outlet thereof; The tail gas treatment module (4) is communicated with the gas phase outlet of the tail gas condenser (3) through the inlet thereof; The circulating pump (6) is communicated with the outlets of the condensation buffer tank (2) and the condensate receiving tank (5) through the inlet thereof, and is communicated with the gas phase inlet of the reactor (1) through the outlet thereof.

9. The system of claim 7, wherein, A valve (7) is arranged on the pipeline connecting the inlet of the condensing buffer tank (2) and the gas phase outlet of the reactor (1).

10. The system of claim 7, wherein, A throttling device (8) is arranged on the pipeline connecting the inlet of the tail gas condenser (3) and the gas phase outlet of the condensing buffer tank (2).

11. The system of claim 10, wherein, The throttling device (8) comprises a flow-limiting orifice plate and / or a regulating valve.

12. The system of claim 8, wherein, The tail gas treatment module (4) comprises one or more of an acid washing tower, an alkali washing tower, a water washing tower and an incinerator.

13. The system of any of claims 8-12, wherein, The tail gas condenser (3) is configured to use circulating water and / or chilled water as the cooling medium, preferably chilled water.

14. The system of claim 13, wherein, The tail gas condenser (3) is configured to use chilled water as the cooling medium.

15. Use of a reaction system according to any one of claims 7 to 14, characterized in that, The method comprises the following steps: a) adding the reactants into the reactor (1), starting the stirrer (20) and reacting under the reaction conditions; b) after the reaction is completed, opening the valve (7) between the reactor (1) and the condensing buffer tank (2) to depressurize and cool the reaction system; c) when the pressure of the reaction system is reduced to 0-0.5 MPa, opening the throttling device (8) to discharge the gas in the reaction system to the tail gas condenser (3), the condensed liquid entering the condensate receiving tank (5) and the condensed gas entering the tail gas treatment module (4); d) after the depressurization is completed, operating the circulating pump (6) to pump the condensed liquid recovered from the condensing buffer tank (2) and the condensate receiving tank (5) back to the reactor as the raw material for the next batch.

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