Continuous and safe production system for preparing hexafluoropropylene

Abstract

The utility model provides a continuous and safe production system for preparing hexafluoropropylene, which is characterized in that the output end of a cracking reaction kettle (4) is respectively communicated with a feeding hole at the bottom of a cracking gas collecting buffer tank I (1) of a main buffer tank and a feeding hole at the bottom of a cracking gas collecting buffer tank II (2) of a standby buffer tank; a discharge hole in the upper part of the pyrolysis gas collecting buffer tank I (1) and a discharge hole in the upper part of the pyrolysis gas collecting buffer tank II (2) are converged into a pipeline and then are communicated with a feed hole of a hexafluoroethylene storage tank (12) through a cooling device (5) and a filtering device in sequence, and a discharge hole of the hexafluoroethylene storage tank (12) is communicated with a rectifying tower (13) for producing hexafluoroethylene; a discharge port II (14) of the filtering device is communicated with a feed port of the directional pulse back flushing system (3), a discharge port of the directional pulse back flushing system (3) is communicated with the waste collecting tank (7), and the hexafluoropropylene preparation device can guarantee safe, continuous and normal operation of hexafluoropropylene preparation.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of safety device for preparing hexafluoropropylene, especially for the system of continuous safety production in preparing hexafluoropropylene. BACKGROUND

[0002] Hexafluoropropylene (English name Hexafluoropropene, simply HFP), molecular formula CF3CFCF2, is one of organic fluorine industrial basic raw materials, and its importance is only second to tetrafluoroethylene, is the comonomer of many fluorine-containing copolymer, also is the intermediate of many fluorine-containing compounds. Hexafluoropropylene preparation approach is more, and industrialization widely adopts tetrafluoroethylene pyrolysis route to produce hexafluoropropylene, and it has the advantages of simple process, higher product purity. Currently commonly used to produce hexafluoropropylene with tetrafluoroethylene pyrolysis, the manufacturing process is: tetrafluoroethylene and octafluorocyclobutane (by-product produced by tetrafluoroethylene cracking) are preheated into tubular reactor cracking conversion into cracking gas with certain ratio, cracking gas is cooled by quenching, filtration, caustic wash, water washing, silica gel dehydration, and then the cracking gas containing trace moisture is input into rectification system for purification, but this reaction system is simply extensive filtration system, and it is not enough to filter small-diameter particulate matter, and the accumulation is serious after a long time, and the production system is blocked, thereby causing system pressure difference to be high, cannot run, must be parked and cleaned, affect the opening rate of device, and also bring certain safety risk, in combination with the special nature of hexafluoropropylene production process being toxic and harmful, not only affect the production time, but also have certain safety risk when equipment is overhauled and cleaned. CONTENT OF UTILITY MODEL

[0003] The utility model provides a kind of system for continuous safety production in preparing hexafluoropropylene, it can guarantee the safe continuous normal operation of hexafluoropropylene preparation.

[0004] The utility model adopts the following technical scheme: a kind of system for continuous safety production in preparing hexafluoropropylene, it includes cracking gas collection buffer tank I and cracking gas collection buffer tank II and directional pulse backflush system, the output end of cracking reactor is divided into two-way pipeline and is connected with the feed inlet of cracking gas collection buffer tank I bottom and the feed inlet of cracking gas collection buffer tank II bottom respectively, wherein cracking gas collection buffer tank I is main buffer tank, cracking gas collection buffer tank II is standby buffer tank, the discharge port of cracking gas collection buffer tank I upper portion and the discharge port of cracking gas collection buffer tank II upper portion are converged into a way pipeline, and then successively through the feed inlet of cooling device and filtration device, the discharge port I of filtration device is connected with the feed inlet of hexafluoroethylene storage tank, the discharge port of hexafluoroethylene storage tank is connected with the rectification column of hexafluoroethylene production, the discharge port II of filtration device is connected with the feed inlet of directional pulse backflush system, the discharge port of directional pulse backflush system is connected with waste collection tank.

[0005] Further, the tank body of the cracking gas collecting buffer tank I and the tank body of the cracking gas collecting buffer tank II are made of Q235 steel material.

[0006] Further, the tank body of the cracking gas collecting buffer tank I and the tank body of the cracking gas collecting buffer tank II are provided with spoiler plates, and the inner walls of the tank body of the cracking gas collecting buffer tank I and the tank body of the cracking gas collecting buffer tank II are provided with pressure sensors and temperature sensors.

[0007] Further, the cooling device is a reaction heat converter, and the medium water in the reaction heat converter is used for cooling.

[0008] Further, the filter device is a precision membrane filter, which comprises a filter cavity, and a filter membrane is arranged in the filter cavity, and the filter membrane divides the filter cavity into an upper gas storage cavity and a lower impurity storage cavity, the discharge port I is arranged on the upper gas storage cavity, and the discharge port II is arranged on the impurity storage cavity.

[0009] Further, the filter membrane is a polytetrafluoroethylene membrane or a polyvinylidene fluoride membrane.

[0010] Further, the directional pulse back-blowing system is a pulse back-blowing cloth bag dust collector.

[0011] The utility model has the following beneficial effects: after the above technical scheme is adopted, the cracking gas collecting buffer tank is used for buffering and decompressing the gas, the precision membrane filter is used for filtering the hexafluoropropylene, and the directional pulse back-blowing system is used for continuously blowing and cleaning the high-boiling substances and particulate matters, so that the rectifying tower is prevented from being blocked by the particulate matters and high-boiling substances, the particulate matters and high-boiling substances are cleaned without stopping the production, the frequency of contacting toxic and harmful substances is reduced or even eliminated, the safety and continuous normal operation of the hexafluoropropylene preparation is ensured, the gas is buffered, the precision membrane filter, the directional pulse back-blowing system and the matched collecting system are used, the stable inlet pressure is ensured by the cracking gas collecting buffer tank, the precision filtering, the system back-blowing and the collecting system are used in a timed, constant-pressure and constant-quantity mode, the efficiency of cleaning the impurities is improved, the operation quality of the monitoring system is monitored by the pressure sensor and the temperature sensor, the buffer tank pressure is improved in time, the safety of the continuous operation is further improved, the cracking gas collecting buffer tank I and the cracking gas collecting buffer tank II are switched and used, and the continuous circulation is used, so that the quality of the safe and continuous operation of the device is ensured, the problems of the long-period high load and the high unit consumption in the hexafluoropropylene production process are solved, and the high-risk problem in the maintenance is solved. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced as follows. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0013] Figure 1 The structure of the present application is shown in the figure. DETAILED DESCRIPTION

[0014] The preferred embodiments of the present application will be described in detail below with reference to the drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and definitely defined.

[0015] In Figure 1The utility model provides a system for preparing hexafluoropropylene continuous safety production, it includes cracking gas collection buffer tank I 1 and cracking gas collection buffer tank II 2 and directional pulse back flushing system 3, the output of cracking reaction kettle 4 is divided into two ways pipelines and is connected with the feed inlet of cracking gas collection buffer tank I 1 bottom and the feed inlet of cracking gas collection buffer tank II 2 bottom respectively, is equipped with switch valve I at the feed inlet of cracking gas collection buffer tank I 1 bottom, is equipped with switch valve II at the feed inlet of cracking gas collection buffer tank II 2 bottom, wherein cracking gas collection buffer tank I 1 is main buffer tank, cracking gas collection buffer tank II 2 is spare buffer tank, the outlet of cracking gas collection buffer tank I 1 upper portion and the outlet of cracking gas collection buffer tank II 2 upper portion are gathered into a way pipeline and are connected with the feed inlet of cooling device 5 and filter device in proper order, the outlet I of filter device 1111 is connected with the feed inlet of hexafluoroethylene storage tank 12, the outlet of hexafluoroethylene storage tank 12 is connected with the rectifying column 13 of hexafluoroethylene production, the outlet II of filter device 14 is connected with the feed inlet of directional pulse back flushing system 3, the outlet of directional pulse back flushing system 3 is connected with waste material collection tank 7, the tank body of cracking gas collection buffer tank I 1 and the tank body of cracking gas collection buffer tank II 2 are all provided with spoiler 8 in the utility model, the inner wall of cracking gas collection buffer tank I 1 and the inner wall of cracking gas collection buffer tank II 2 are all installed with pressure sensor 9 and temperature sensor 10, the cooling device 5 of the utility model is provided with reaction heat converter, and cooling is carried out after conversion by medium water in reaction heat converter, the filter device of the utility model is provided with precision membrane filter 6, precision membrane filter 6 includes filter chamber 15, filter membrane 16 is arranged in filter chamber 15, filter membrane 16 divides filter chamber 15 into upper gas storage chamber 17 and lower impurity storage chamber 18, outlet I 1111 is located on upper gas storage chamber 17, outlet II 14 is located on impurity storage chamber 18, filter membrane 16 is polytetrafluoroethylene membrane or polyvinylidene fluoride membrane, the filter membrane 16 of the utility model preferably adopts polytetrafluoroethylene membrane, directional pulse back flushing system 3 is provided with pulse back flushing cloth bag dust collector, and the pulse back flushing cloth bag dust collector is connected with closed gas supply system, and the closed gas supply system provides high-pressure gas for the pulse back flushing cloth bag dust collector.

[0016] The use process of the utility model is: the utility model puts tetrafluoroethylene into the cracking reactor 4 to obtain hexafluoroethylene, opens the switch valve I, the hexafluoroethylene gas obtained after cracking enters the cracking gas collection buffer tank I 1 from the bottom feed inlet from bottom to top, the gas inflow is treated by the pressure of the spoiler 8, the pressure of the stable gas is entered, the other cracking gas collection buffer tank II 2 is the standby buffer tank, the cracking gas collection buffer tank I 1 and the cracking gas collection buffer tank II 2 are switched to use, in order to prevent the explosion requirement, the pressure sensor 9 and the temperature sensor 10 are used to monitor the pressure and temperature of the cracking gas collection buffer tank I 1, then the stable gas is entered into the reaction heat converter from the discharge port of the cracking gas collection buffer tank I 1, the medium water in the reaction heat converter is converted to cool, then the cooled hexafluoroethylene gas is discharged into the precision membrane filter 6 to filter, the precision membrane filter 6 filters by the micropore structure of the membrane, the filtered hexafluoroethylene gas is directly discharged into the hexafluoroethylene storage tank 12 for storage through the discharge port I 11, finally, the gas is discharged into the rectifying column 13 to carry out rectification treatment, the high-boiling substance and the particulate matter generated after cracking are collected in the waste collection tank 7 by the pulse back-blowing cloth bag dust collector through the pulse back-blowing cloth bag dust collector, so that the impurities are effectively avoided to be brought into the rectification preparation of hexafluoroethylene to block the rectifying column 13, so that the continuous and safe production of hexafluoropropylene is achieved, in the process of blowing, the pulse back-blowing cloth bag dust collector is provided with high-pressure gas by the closed gas supply system, when the pressure and temperature monitored in the cracking gas collection buffer tank I 1 are too high and do not meet the explosion-proof requirement, the switch valve I of the cracking gas collection buffer tank I 1 can be closed, the switch valve II of the cracking gas collection buffer tank II 2 is switched to open, and the cracking gas collection buffer tank II 2 is used for gas buffer treatment.

[0017] Not limited to this, any change or replacement without creative labor is covered in the protection scope of the utility model. Therefore, the protection scope of the utility model should be limited by the protection scope of the claims.

Claims

1. A system for the continuous safe production of hexafluoropropene, characterized in that It includes cracking gas collection buffer tank I (1) and cracking gas collection buffer tank II (2) and directional pulse back flushing system (3), the output end of cracking reactor (4) is connected with the feed inlet of the bottom of cracking gas collection buffer tank I (1) and the feed inlet of the bottom of cracking gas collection buffer tank II (2) through two pipelines respectively, wherein cracking gas collection buffer tank I (1) is the main buffer tank, cracking gas collection buffer tank II (2) is the standby buffer tank, the outlet of the upper part of cracking gas collection buffer tank I (1) and the outlet of the upper part of cracking gas collection buffer tank II (2) are connected into a pipeline, then the pipeline is connected with the feed inlet of the cooling device (5) and the feed inlet of the filtering device in turn, the outlet I (11) of the filtering device is connected with the feed inlet of the hexafluoroethylene storage tank (12), the outlet of the hexafluoroethylene storage tank (12) is connected with the rectifying column (13) of hexafluoroethylene production, the outlet II (14) of the filtering device is connected with the feed inlet of the directional pulse back flushing system (3), the outlet of the directional pulse back flushing system (3) is connected with the waste collection tank (7).

2. The system for continuous safe production in preparation of hexafluoropropylene according to claim 1, characterized in that The tank body of cracking gas collection buffer tank I (1) and the tank body of cracking gas collection buffer tank II (2) are made of Q235 steel material.

3. The system for continuous safe production in preparation of hexafluoropropylene according to claim 1, characterized in that The tank body of cracking gas collection buffer tank I (1) and the tank body of cracking gas collection buffer tank II (2) are provided with turbulence plates (8) inside, and the inner wall of the tank body of cracking gas collection buffer tank I (1) and the inner wall of the tank body of cracking gas collection buffer tank II (2) are provided with pressure sensors (9) and temperature sensors (10).

4. The system for continuous safe production in preparation of hexafluoropropylene according to claim 1, characterized in that The cooling device (5) is a reaction heat converter, and the medium water in the reaction heat converter is used for cooling after conversion.

5. The system for continuous safe production in preparation of hexafluoropropylene according to claim 1, characterized in that The filtering device is a precision membrane filter (6), the precision membrane filter (6) comprises a filtering cavity (15), the filtering cavity (15) is provided with a filtering membrane (16), the filtering membrane (16) divides the filtering cavity (15) into an upper gas storage cavity (17) and a lower impurity storage cavity (18), the outlet I (11) is located on the upper gas storage cavity (17), and the outlet II (14) is located on the impurity storage cavity (18).

6. The system for preparing continuous safe production of hexafluoropropylene according to claim 5, characterized in that The filtering membrane (16) is a polytetrafluoroethylene membrane or a polyvinylidene fluoride membrane.

7. The system for continuous safe production in preparation of hexafluoropropylene according to claim 1, characterized in that The directional pulse back flushing system (3) is a pulse back flushing cloth bag dust collector.

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