Novel electric heating tetrafluoroethylene cracking furnace

Abstract

The novel cracking furnace comprises an electric heating reactor, a mixer, an electric heating R22 preheater, an electric heating high-temperature steam furnace and a temperature control system, and the temperature control system is composed of a DCS control module, an R22 power supply control module, a power supply module, a steam furnace control module, a reactor power supply control module and a temperature signal transfer module. The DCS control module controls the R22 power supply control module, the power supply module, the steam furnace control module and the reactor power supply control module, and the temperature signal transfer module receives temperature information of the electric heating reactor, the electric heating R22 preheater and the electric heating high-temperature steam furnace in real time and transmits the temperature information to the DCS control module in real time. According to the utility model, the temperature is accurately controlled through the temperature control system, byproducts are reduced, raw materials are saved, the product quality is improved, carbon emission is reduced, the system is more environment-friendly, the generation of waste acid water is reduced, the hazardous waste treatment cost is reduced, flammable and explosive fuels are not needed, the field is changed from an anti-explosion environment to a common environment, the danger level is reduced, and the production safety is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of tetrafluoroethylene production equipment, in particular to a new type of cracking furnace for producing tetrafluoroethylene by electric heating. Background Art

[0002] Tetrafluoroethylene (TFE), a colorless and odorless gas with a melting point of -142.5°C and a boiling point of -76.3°C, is an important monomer for synthesizing polytetrafluoroethylene resin, as well as other fluoroplastics, fluororubbers, and perfluoropropylene. It is widely used in fluorosurfactants, fine chemicals, and medicines.

[0003] At present, the preparation method of tetrafluoroethylene at home and abroad mainly uses difluorochloromethane (R22) as raw material and produces it by thermal decomposition reaction at high temperature.

[0004] The reaction equation is: 2CHClF2→CF2=CF2+2HCl. A platinum-lined tube is used as the cracking reaction tube, and superheated steam is used as the diluent. The cracking is carried out at a temperature of 600-900°C to obtain tetrafluoroethylene. After cooling and separation, water washing and alkali washing to remove hydrogen chloride, and then pressure distillation at -20°C and 2.02MPa, a polymer-grade pure product with a content of more than 99.9% can be obtained.

[0005] However, the existing production process of tetrafluoroethylene cracking has the following defects:

[0006] 1. Currently, the cracking furnaces used in tetrafluoroethylene production use natural gas or oil as fuel. The exhaust gas generated by the combustion is discharged into the atmosphere through the chimney, which will pollute the environment. Secondly, the use of natural gas or oil as fuel requires higher safety measures in the production workshop. The equipment and facilities used in the workshop must be explosion-proof. The price of explosion-proof equipment is high, which leads to increased production costs.

[0007] 2. The cracking furnace uses natural gas or oil as fuel, which results in uneven heating and makes it difficult to accurately control the temperature inside the furnace. The temperature in each area of ​​the furnace is different, and the by-products at different temperatures are also different, which leads to complex by-products during the cracking reaction and affects the quality of the product.

[0008] 3. For cracking furnaces that use natural gas or oil as fuel, a large amount of waste acid water is produced after production, and the cost of hazardous waste treatment is high. Utility Model Content

[0009] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a new electric heating cracking furnace for producing tetrafluoroethylene. Compared with the traditional production process, the system can achieve precise control of the reaction temperature, reduce by-products, save raw materials, and improve product quality; there is no waste gas emission from fuel combustion, which reduces the generation of waste acid water and reduces environmental pollution; no flammable and explosive fuel is required, the site environment is changed from an explosion-proof environment to a general environment, the risk level is reduced, and production safety is higher.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] A novel electric-heated tetrafluoroethylene cracking furnace comprises a cracking furnace body, which is composed of an electric reactor, a mixer, an electric R22 preheater, an electric high-temperature steam furnace, and a temperature control system. The temperature control system comprises a DCS control module, an R22 power supply control module, a power supply module, a steam furnace control module, a reactor power supply control module, and a temperature signal transfer module.

[0012] The DCS control module is used to control the R22 power supply control module, the power supply module, the steam furnace control module and the reactor power supply control module;

[0013] The temperature signal transfer module is used to receive the temperature information transmitted by the electric reactor, the electric R22 preheater and the electric high-temperature steam furnace in real time, and the temperature signal transfer module transmits the received temperature information to the DCS control module in real time;

[0014] The R22 power supply control module is used to control the heating of the electric R22 preheater and set the temperature of the electric R22 preheater;

[0015] The power supply module is used to supply power to the DCS control module, the R22 power supply control module, the steam furnace control module and the reactor power supply control module;

[0016] The steam furnace control module is used to control the heating of the electric high-temperature steam furnace and set the temperature of the electric high-temperature steam furnace;

[0017] The reactor power supply control module is used to control the heating of the electrothermal reactor and set the temperature of the electrothermal reactor;

[0018] The mixer is connected in series with the electrothermal reactor.

[0019] Furthermore, the DCS control module controls the R22 power supply control module and the steam furnace control module to respectively start the electric R22 preheater and the electric high-temperature steam furnace for heating, and sets the temperatures of the electric R22 preheater and the electric high-temperature steam furnace to 450° C. and 950° C., respectively. The temperature signal transfer module receives temperature information at the outlets of the electric R22 preheater and the electric high-temperature steam furnace in real time, and transmits the received temperature information to the DCS control module in real time.

[0020] When in use, the DCS control module sets the temperature of the electric R22 preheater and the electric high-temperature steam furnace to 450°C and 950°C respectively through the R22 power supply control module and the steam furnace control module. The temperature signal transfer module receives the temperature information at the outlet of the electric R22 preheater and the electric high-temperature steam furnace in real time.

[0021] 1. If the temperature information transmitted by the temperature signal transfer module to the DCS control module shows that the temperatures at the outlets of the electric R22 preheater and the electric high-temperature steam furnace are both lower than the set temperature, the DCS control module controls the electric R22 preheater and the electric high-temperature steam furnace through the R22 power supply control module and the steam furnace control module respectively to continue heating until the temperature information transmitted by the temperature signal transfer module to the DCS control module shows that the temperatures at the outlets of the electric R22 preheater and the electric high-temperature steam furnace have reached the set temperature. Then, the 950°C steam branch pipes and the 450°C R22 branch pipes are respectively merged and then mixed in the mixer. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature and then enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0022] 2. If the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric R22 preheater is lower than the set temperature, and the temperature at the outlet of the electric high-temperature steam furnace has reached the set temperature, the DCS control module controls the electric R22 preheater through the R22 power supply control module to continue heating, and the steam furnace control module controls the electric heater to reduce the input power, thereby reducing the heating efficiency of the electric high-temperature steam furnace and performing heat preservation. After the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric R22 preheater has reached the set temperature, the 950°C steam branches and the 450°C R22 branches are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature and enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0023] 3. If the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric high-temperature steam furnace is lower than the set temperature, and the temperature at the outlet of the electric R22 preheater has reached the set temperature, the DCS control module controls the electric high-temperature steam furnace through the steam furnace control module to continue heating, and the R22 power supply control module controls the electric R22 preheater to reduce the input power, thereby reducing the heating efficiency of the electric R22 preheater and performing heat preservation. After the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric high-temperature steam furnace has reached the set temperature, the 950°C steam branches and the 450°C R22 branches are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature, and then enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation and processing equipment in sequence.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0025] Compared with the traditional combustion cracking furnace, the utility model

[0026] 1. The temperature control system realizes precise temperature control. Electric heating is adopted to achieve uniform heating, small temperature difference in each area, reducing by-products, saving raw materials and improving product quality.

[0027] 2. The electric heating method eliminates the need to emit combustion exhaust gas, reduces carbon emissions, is more environmentally friendly, and creates a green factory. At the same time, the temperature of R22 is precisely controlled to achieve an immediate reaction after confluence with high-temperature steam, resulting in a more complete reaction and less steam waste, thereby reducing the generation of waste acid water and lowering the cost of hazardous waste treatment;

[0028] 3. The electric heating reactor adopts electric heating, which does not require flammable and explosive fuels. The site is changed from an explosion-proof environment to a general environment, the danger level is reduced, and production safety is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and constitute a limitation of the present invention.

[0030] In the attached figure:

[0031] Figure 1 This is a flow chart of the cracking furnace control system of the utility model. DETAILED DESCRIPTION

[0032] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present invention will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solutions of the present invention may be practiced while omitting one or more of the specific details, or that other methods, components, devices, steps, etc. may be employed. In other cases, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of the present invention.

[0033] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they can refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art will understand the specific meanings of the above terms in this patent based on the specific circumstances.

[0034] According to an embodiment of the utility model, a new type of cracking furnace for producing tetrafluoroethylene by electric heating is provided.

[0035] Example:

[0036] like Figure 1 As shown, a new electric heating tetrafluoroethylene cracking furnace includes a cracking furnace body, which is composed of an electric heating reactor, a mixer, an electric heating R22 preheater, an electric heating high-temperature steam furnace, and a temperature control system. The temperature control system is composed of a DCS control module, an R22 power supply control module, a power supply module, a steam furnace control module, a reactor power supply control module, and a temperature signal transfer module.

[0037] The DCS control module is used to control the R22 power control module, power supply module, steam boiler control module and reactor power control module;

[0038] The temperature signal transfer module is used to receive the temperature information transmitted by the electric reactor, electric R22 preheater and electric high-temperature steam furnace in real time. The temperature signal transfer module transmits the received temperature information to the DCS control module in real time;

[0039] The R22 power supply control module is used to control the heating of the electric R22 preheater and set the temperature of the electric R22 preheater;

[0040] The power supply module is used to supply power to the DCS control module, R22 power supply control module, steam boiler control module, and reactor power supply control module. The power supply module is a 10 / 0.38kV dedicated substation without a magnetic voltage regulator, eliminating primary loss and reducing power loss. The R22 power supply control module, steam boiler control module, and reactor power supply control module supply electricity to the electric R22 preheater, electric high-temperature steam boiler, and electric reactor, respectively.

[0041] The steam furnace control module is used to control the heating of the electric high-temperature steam furnace and set the temperature of the electric high-temperature steam furnace;

[0042] The reactor power control module is used to control the heating of the electrothermal reactor and set the temperature of the electrothermal reactor. The electrothermal reactor adopts electric heating, and the heat distribution in the reactor is uniform, with small temperature differences in different areas, which reduces by-products, saves raw materials, and improves product quality. In addition, no flammable and explosive fuels are required, and there are no flammable and explosive materials in the workshop, which reduces the risk level and improves production safety. At the same time, all lighting fixtures, maintenance boxes, socket boxes, terminal boxes, control boxes, cable connectors, substations, etc. do not need to use explosion-proof equipment, which reduces equipment and facility costs.

[0043] The mixer and the electrothermal reactor are connected in series. There are six main branch pipes on the mixer. Two branch pipes are provided at the other end of each group of main branch pipes. One branch pipe is connected to high-temperature steam, and the other branch pipe is connected to high-temperature R22. The high-temperature steam and high-temperature R22 are respectively collected into the main branch pipes through their respective branch pipes, and then mixed in the main branch pipes and then mixed in the mixer. Finally, they are concentrated from the mixer into the electrothermal reactor.

[0044] Compared with the traditional mixer with only two large pipes (one for high-temperature steam and one for high-temperature R22, where the high-temperature steam and high-temperature R22 are mixed in the mixer), the mixer with six main branch pipes provides more uniform contact and mixing, which is conducive to faster reactions in subsequent steps.

[0045] The DCS control module controls the R22 power supply control module and the steam furnace control module to start the electric R22 preheater and the electric high-temperature steam furnace heating respectively, and sets the temperatures of the electric R22 preheater and the electric high-temperature steam furnace to 450°C and 950°C respectively. The temperature signal transfer module receives the temperature information at the outlets of the electric R22 preheater and the electric high-temperature steam furnace in real time, and transmits the received temperature information to the DCS control module in real time.

[0046] During use, the DCS control module sets the temperature of the electric R22 preheater and the electric high-temperature steam furnace to 450°C and 950°C respectively through the R22 power supply control module and the steam furnace control module. This accurately controls the temperature of R22 and high-temperature steam, allowing R22 and high-temperature steam to react immediately after they merge, thus steadily reducing the waste of high-temperature steam and, in turn, the generation of waste acid water.

[0047] If the temperature information transmitted by the temperature signal transfer module to the DCS control module shows that the temperatures at the outlets of the electric R22 preheater and the electric high-temperature steam furnace are both lower than the set temperature, the DCS control module controls the electric R22 preheater and the electric high-temperature steam furnace through the R22 power supply control module and the steam furnace control module respectively to continue heating until the temperature information transmitted by the temperature signal transfer module to the DCS control module shows that the temperatures at the outlets of the electric R22 preheater and the electric high-temperature steam furnace have reached the set temperature. Then, the 950°C steam branch pipes and the 450°C R22 branch pipes are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature and enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0048] If the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric R22 preheater is lower than the set temperature, and the temperature at the outlet of the electric high-temperature steam furnace has reached the set temperature, the DCS control module controls the electric R22 preheater to continue heating through the R22 power supply control module, and the steam furnace control module controls the electric heating to reduce the input power, reduce the heating efficiency of the electric high-temperature steam furnace, and keep warm. After the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric R22 preheater has reached the set temperature, the 950°C steam branches and the 450°C R22 branches are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature, and then enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0049] If the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric high-temperature steam furnace is lower than the set temperature, and the temperature at the outlet of the electric R22 preheater has reached the set temperature, the DCS control module controls the electric high-temperature steam furnace through the steam furnace control module to continue heating, and the R22 power supply control module controls the electric R22 preheater to reduce the input power, thereby reducing the heating efficiency of the electric R22 preheater and performing heat preservation. After the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric high-temperature steam furnace has reached the set temperature, the 950°C steam branches and the 450°C R22 branches are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature, and then enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0050] The working principle of this utility model:

[0051] A power supply module consisting of a 10 / 0.38kV dedicated substation is used to supply power to the DCS control module, R22 power control module, steam boiler control module, and reactor power control module. The R22 power control module, steam boiler control module, and reactor power control module then supply electricity to the electric R22 preheater, electric high-temperature steam boiler, and electric reactor respectively.

[0052] The DCS control module controls the heating of the electric reactor by controlling the reactor power control module and sets the temperature of the electric reactor. It also starts the electric R22 preheater and the electric high-temperature steam furnace by controlling the R22 power control module and the steam furnace control module, and sets the temperatures of the electric R22 preheater and the electric high-temperature steam furnace to 450°C and 950°C, respectively. The temperature signal transfer module receives the temperature information at the outlets of the electric R22 preheater and the electric high-temperature steam furnace, as well as the temperature information of the electric reactor, and transmits the received temperature information to the DCS control module in real time.

[0053] If the temperature information transmitted by the temperature signal transfer module to the DCS control module shows that the temperatures at the outlets of the electric R22 preheater and the electric high-temperature steam furnace are both lower than the set temperature, the DCS control module controls the electric R22 preheater and the electric high-temperature steam furnace through the R22 power supply control module and the steam furnace control module respectively to continue heating until the temperature information transmitted by the temperature signal transfer module to the DCS control module shows that the temperatures at the outlets of the electric R22 preheater and the electric high-temperature steam furnace have reached the set temperature. Then, the 950°C steam branch pipes and the 450°C R22 branch pipes are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature and enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0054] If the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric R22 preheater is lower than the set temperature, and the temperature at the outlet of the electric high-temperature steam furnace has reached the set temperature, the DCS control module controls the electric R22 preheater to continue heating through the R22 power supply control module, and the steam furnace control module controls the electric heating to reduce the input power, reduce the heating efficiency of the electric high-temperature steam furnace, and keep warm. After the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric R22 preheater has reached the set temperature, the 950°C steam branches and the 450°C R22 branches are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature, and then enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0055] If the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric high-temperature steam furnace is lower than the set temperature, and the temperature at the outlet of the electric R22 preheater has reached the set temperature, the DCS control module controls the electric high-temperature steam furnace through the steam furnace control module to continue heating, and the R22 power supply control module controls the electric R22 preheater to reduce the input power, thereby reducing the heating efficiency of the electric R22 preheater and performing heat preservation. After the temperature information transmitted to the DCS control module by the temperature signal transfer module shows that the temperature at the outlet of the electric high-temperature steam furnace has reached the set temperature, the 950°C steam branches and the 450°C R22 branches are respectively merged and then enter the mixer for mixing. After proper heating, the mixed 950°C steam and 450°C R22 reach the reaction temperature, and then enter the electric reactor to start the electric thermal cracking reaction to produce tetrafluoroethylene. Finally, the tetrafluoroethylene enters the cooling system and separation treatment equipment in sequence.

[0056] Therefore, compared with traditional combustion cracking furnaces, the utility model realizes precise temperature control through the temperature control system, adopts electric heating, heats evenly, has small temperature differences in different areas, reduces by-products, saves raw materials, and improves product quality; the electric heating method eliminates the need to discharge combustion exhaust gas, reduces carbon emissions, is more environmentally friendly, and creates a green factory; at the same time, the temperature of R22 is precisely controlled to achieve immediate reaction after merging with high-temperature steam, which makes the reaction more complete, reduces steam waste, and thus reduces the generation of waste acid water and reduces the cost of hazardous waste treatment; the electric reactor adopts electric heating, does not require flammable and explosive fuels, and the site is changed from an explosion-proof environment to a general environment, the danger level is reduced, and production safety is higher.

[0057] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0058] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A novel electric heating tetrafluoroethylene cracking furnace, comprising a cracking furnace body, characterized in that: The cracking furnace body is composed of an electric reactor, a mixer, an electric R22 preheater, an electric high-temperature steam furnace and a temperature control system. The temperature control system is composed of a DCS control module, an R22 power supply control module, a power supply module, a steam furnace control module, a reactor power supply control module and a temperature signal transfer module. The DCS control module is used to control the R22 power supply control module, the power supply module, the steam furnace control module and the reactor power supply control module; The temperature signal transfer module is used to receive the temperature information transmitted by the electric reactor, the electric R22 preheater and the electric high-temperature steam furnace in real time, and the temperature signal transfer module transmits the received temperature information to the DCS control module in real time; The R22 power supply control module is used to control the heating of the electric R22 preheater and set the temperature of the electric R22 preheater; The power supply module is used to supply power to the DCS control module, the R22 power supply control module, the steam furnace control module and the reactor power supply control module; The steam furnace control module is used to control the heating of the electric high-temperature steam furnace and set the temperature of the electric high-temperature steam furnace; The reactor power supply control module is used to control the heating of the electrothermal reactor and set the temperature of the electrothermal reactor; The mixer is connected in series with the electrothermal reactor.

2. The novel electric heating tetrafluoroethylene cracking furnace according to claim 1, characterized in that: The DCS control module controls the R22 power supply control module and the steam furnace control module to respectively start the electric R22 preheater and the electric high-temperature steam furnace for heating, and at the same time sets the temperatures of the electric R22 preheater and the electric high-temperature steam furnace to 450°C and 950°C, respectively. The temperature signal transfer module receives temperature information at the outlets of the electric R22 preheater and the electric high-temperature steam furnace in real time, and transmits the received temperature information to the DCS control module in real time.

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