Synthesis reactor for o-fluorotoluene

Abstract

The utility model relates to a chemical production technical field especially relates to a kind of o-fluorotoluene synthetic reaction kettle, including the kettle body for synthesizing o-fluorotoluene, vent pipe is equipped on the kettle body, relief valve is equipped on the vent pipe, the output end of vent pipe is equipped with the purification unit for the mixed gas that is discharged from vent pipe is handled, the purification unit includes the condensation recovery portion that is communicated with vent pipe and the adsorption portion that is connected with condensation recovery portion in turn along gas flow direction, the utility model is condensed by condensation recovery portion, and the mixed gas that is discharged from vent pipe is condensed, part mixed gas is condensed into liquid and is recycled, and the waste of raw material is reduced, and the gas after condensation recovery then enters the inside of downstream adsorption portion, and harmful gas in mixed gas is then adsorbed by adsorption portion, then the gas after being adsorbed is discharged by discharge pipe, and the pollution to environment is reduced.

Description

Technical Field

[0001] This utility model relates to the field of chemical production technology, and in particular to a reaction vessel for the synthesis of o-fluorotoluene. Background Technology

[0002] o-fluorotoluene, as an important organic chemical intermediate, is widely used in pharmaceuticals, pesticides, dyes and fluorine materials. In the industrial synthesis of o-fluorotoluene, it is usually prepared by substitution reaction of toluene with fluorine-containing reagents under specific reaction conditions. During the reaction, key steps such as material mixing, reaction and product separation need to be achieved through a reaction vessel.

[0003] However, during the synthesis of o-fluorotoluene, a certain amount of gas is generated inside the reactor due to the reaction, leading to excessive pressure inside the reactor. To maintain pressure balance and ensure stable reaction, the internal gas needs to be released by opening the pressure relief valve. However, this gas includes unreacted toluene vapor, generated o-fluorotoluene vapor, and corrosive gases such as hydrogen fluoride, which are reaction byproducts. If these gases are released directly, a large amount of useful materials will escape with the vented gas. Unreacted toluene and the product o-fluorotoluene have high economic value. Their escape not only causes serious waste of raw materials but also directly reduces the reaction yield and increases production costs. Furthermore, the direct emission of corrosive gases such as hydrogen fluoride contained in the vented gas will cause serious environmental pollution, endangering the ecological environment and the health of operators. Current technologies generally use absorption devices for simple treatment, but this still results in resource waste and environmental pollution.

[0004] Therefore, based on the above situation, it is necessary to design an o-fluorotoluene synthesis reactor to solve the above problems. Utility Model Content

[0005] This invention provides a reactor for the synthesis of o-fluorotoluene to solve the problems in the prior art.

[0006] The technical problem solved by this utility model is achieved by the following technical solution: An o-fluorotoluene synthesis reactor includes a reactor body for synthesizing o-fluorotoluene. The reactor body is equipped with a vent pipe and a pressure relief valve. The output end of the vent pipe is equipped with a purification unit for treating the mixed gas released from the vent pipe. The purification unit includes a condensation recovery section connected to the vent pipe and an adsorption section connected to the condensation recovery section, arranged sequentially along the gas flow direction. The condensation recovery section is used to condense the mixed gas and return it to the reactor body. The adsorption section is used to adsorb harmful gases discharged from the condensation recovery section. The output end of the adsorption section is equipped with a discharge pipe.

[0007] Preferably, the condensation recovery unit includes a condensation channel connected to the vent pipe, a cooling coil disposed on the condensation channel for connecting an external cooling medium, and a return pipe connected to the condensation channel, wherein the output end of the return pipe is connected to the vessel body.

[0008] Preferably, the reflux pipe is provided with a liquid seal section, which is used to block the flow of gas from the vessel body to the condensation recovery section, and allows the condensed liquid material to flow back into the vessel body through the liquid seal section.

[0009] Preferably, the adsorption section is a packed adsorption tower, and the adsorption section is filled with an adsorbent for adsorbing harmful gases.

[0010] Preferably, the diameter of the discharge pipe gradually increases along the gas flow direction.

[0011] Preferably, the purification unit and the vent pipe are detachably connected via a flange.

[0012] The beneficial effects of this invention are as follows: the mixed gas released from the vent pipe is condensed by the condensation recovery unit, and a portion of the mixed gas is condensed into liquid and recovered, reducing the waste of raw materials. The gas after condensation recovery then enters the downstream adsorption unit, where harmful gases in the mixed gas are adsorbed. The adsorbed gas is then discharged through the discharge pipe, reducing environmental pollution. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0014] Figure 1 A three-dimensional structural schematic diagram provided for this utility model; Figure 2 A front view structural schematic diagram provided for this utility model; Figure 3 This is a cross-sectional structural diagram provided for this utility model.

[0015] In the diagram, 1 is the vessel body; 2 is the vent pipe; 3 is the pressure relief valve; 4 is the condensation recovery section; 41 is the condensation channel; 42 is the cooling coil; 43 is the reflux pipe; 5 is the adsorption section; 6 is the discharge pipe; and 7 is the liquid seal section. Detailed Implementation

[0016] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0017] Reference Figures 1-3 As shown, an o-fluorotoluene synthesis reactor includes a reactor body 1. The reactor body 1 is generally equipped with a stirring device. By putting raw materials into the reactor body 1, the stirring device mixes and stirs the raw materials, and a reaction occurs. During the reaction, both toluene and the reaction product o-fluorotoluene are volatile and will form vapors at the reaction temperature. The accumulation of these gases will cause the pressure inside the reactor to gradually increase. If not discharged in time, it may exceed the pressure limit of the equipment, causing leakage or even explosion risks. Therefore, a pressure monitoring device is generally installed on the reactor. A vent pipe 2 is provided on the reactor body 1, and a pressure relief valve 3 is provided on the vent pipe 2. When the pressure monitoring device detects that the pressure is too high, it will control the pressure relief valve 3 to open through the set control device, so that the gas inside the reactor body 1 can be discharged from the vent pipe 2. The discharged gas contains raw materials, harmful gases, etc. In order to reduce the waste of raw materials and the release of harmful gases, the discharged mixed gas needs to be purified. A purification unit for treating the mixed gas released from the vent pipe 2 is provided at the output end of the vent pipe 2. The purification unit includes a condensation recovery section 4 connected to the vent pipe 2 and an adsorption section 5 connected to the condensation recovery section 4, which are arranged sequentially along the gas flow direction. When the mixed gas is released from the vent pipe 2, the mixed gas first enters the condensation recovery section 4. Then, the condensation recovery section 4 cools a portion of the mixed gas, such as toluene vapor and o-fluorotoluene vapor, to liquefy it into a liquid and recycles the liquid for reuse, so as to reduce the waste of raw materials during the emission process. Then, another portion of the mixed gas gradually enters the adsorption section 5. The adsorption section 5 adsorbs harmful gases, such as hydrogen fluoride, and finally obtains the purified gas, which is then discharged through the emission pipe 6 provided at the output end of the adsorption section 5, reducing the environmental pollution caused by the release of harmful gases.

[0018] Reference Figure 3 As shown, further, during the purification process, the condensation recovery unit 4 includes a condensation channel 41, a cooling coil 42, and a return pipe 43. The condensation channel 41 is connected to the output end of the vent pipe 2. The mixed gas discharged in the vent pipe 2 then enters the condensation channel 41. At the same time, the cooling coil 42 is connected to an external refrigeration device, such as a refrigeration element, to cool the cooling medium. The cooling medium then enters the cooling coil 42 and circulates within it. The cooling coil 42 is wrapped in a jacket on the outer wall of the cooling pipe and cools the inside of the cooling pipe. Then, the steam and other gases are liquefied into liquid and flow into the return pipe 43, which then flows into the vessel body 1 for reuse.

[0019] The return pipe 43 is equipped with a liquid seal section 7, which is U-shaped. The U-shaped liquid seal section 7 blocks the gas while not hindering the return of the condensed liquid material. The liquid can flow naturally through the U-shaped bend of the liquid seal section 7 and enter the vessel body 1 by gravity, realizing the recycling and reuse of useful materials. During normal operation, the U-shaped liquid seal section 7 will accumulate a certain height of condensed liquid to form a liquid column. When the gas inside the vessel body 1 attempts to enter the condensation recovery section 4 in reverse through the return pipe 43, it must overcome the static pressure generated by the liquid column. At the same time, the liquid seal height is designed according to the pressure inside the vessel body 1, such as 10 cm water column, which only allows the condensed liquid to flow back and prevents the liquid from flowing back.

[0020] Reference Figures 1-3 As shown, further, the adsorption section 5 is a packed adsorption tower, and the interior of the adsorption section 5 is filled with adsorbent. The adsorbent can adsorb harmful gases in the mixed gas. The harmful gases produced in the synthesis of o-fluorotoluene are mainly byproduct HF and a small amount of uncondensed acidic gases. The adsorbent is usually a basic solid adsorbent, such as activated alumina, which neutralizes HF through the surface basic groups: Al2O3 + 6HF → 2AlF3 + 3H2O, achieving chemical adsorption. Anhydrous calcium chloride and sodium fluoride particles, NaF + HF = NaHF2, specifically adsorb HF, reducing the pollution of gas emissions.

[0021] Reference Figure 3 As shown, after the purified gas is purified, it is discharged through the discharge pipe 6. The diameter of the discharge pipe 6 gradually increases along the gas flow direction. The purified gas is safely discharged through the discharge pipe 6. As the pipe diameter gradually increases, the gas flow cross-sectional area increases accordingly. Under the condition of constant flow rate, the flow velocity will decrease as the cross-sectional area increases. This design can reduce the flow resistance of gas in the pipe, reduce the power loss of the system, and avoid generating high-frequency airflow noise.

[0022] Reference Figure 1 As shown, the purification unit and the vent pipe 2 are detachably connected by a flange. The flange connection can form a reliable sealing structure by setting corrosion-resistant sealing gaskets, such as polytetrafluoroethylene gaskets, on the contact surface to prevent the leakage of corrosive gases. The condensation recovery section 4 and the adsorption section 5 in the purification unit are components that require regular maintenance, such as cleaning residual materials in the condensation channel 41, replacing the failed adsorbent, and overhauling the cooling components. The flange connection can be quickly separated from the purification unit and the vent pipe 2 by removing the bolts, without the need to cut or weld the entire pipeline, thus shortening the maintenance time.

[0023] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A reactor for synthesizing o-fluorotoluene, comprising a reactor body (1) for synthesizing o-fluorotoluene, wherein the reactor body (1) is provided with a vent pipe (2), and the vent pipe (2) is provided with a pressure relief valve (3), characterized in that, The vent pipe (2) is provided with a purification unit for processing the mixed gas released from the vent pipe (2). The purification unit includes a condensation recovery section (4) connected to the vent pipe (2) and an adsorption section (5) connected to the condensation recovery section (4) arranged sequentially along the gas flow direction. The condensation recovery section (4) is used to condense the mixed gas and return it to the inside of the vessel body (1). The adsorption section (5) is used to adsorb the harmful gas discharged from the condensation recovery section (4). The output end of the adsorption section (5) is provided with a discharge pipe (6).

2. The o-fluorotoluene synthesis reactor according to claim 1, characterized in that, The condensation recovery unit (4) includes a condensation channel (41) connected to the vent pipe (2), a cooling coil (42) provided on the condensation channel (41) and used for external cooling medium connection, and a return pipe (43) connected to the condensation channel (41). The output end of the return pipe (43) is connected to the vessel body (1).

3. The o-fluorotoluene synthesis reactor according to claim 2, characterized in that, The return pipe (43) is provided with a liquid seal section (7) arranged in a "U" shape. The liquid seal section (7) is used to block the flow of gas from the vessel body (1) to the condensation recovery section (4) and allow the condensed liquid material to flow back to the interior of the vessel body (1) through the liquid seal section (7).

4. The o-fluorotoluene synthesis reactor according to claim 1, characterized in that, The adsorption section (5) is a packed adsorption tower, and the adsorption section (5) is filled with an adsorbent for adsorbing harmful gases.

5. The o-fluorotoluene synthesis reactor according to claim 1, characterized in that, The diameter of the discharge pipe (6) gradually increases along the gas flow direction.

6. The o-fluorotoluene synthesis reactor according to claim 1, characterized in that, The purification unit and the vent pipe (2) are detachably connected via a flange.

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