Multi-stage tandem liquid paraffin chlorination reaction and chlorine recovery system and method

Abstract

The invention relates to the technical field of chlorinated paraffin production, and discloses a multi-stage tandem liquid paraffin chlorination reaction and chlorine recovery system and method, which comprises a pre-reaction section, a main reaction section and a semi-finished product kettle, the pre-reaction section comprises a continuous feeding device, a liquid paraffin conveying pipeline, a No.1 side reaction kettle, a No.2 side reaction kettle, a No.3 side reaction kettle, a No.4 side reaction kettle, a No.5 side reaction kettle, a No.6 side reaction kettle, a secondary jacket circulating water cooling device, a secondary circulating water pipe, a waste gas treatment device and a waste gas pipeline; ultraviolet lamps are arranged in the first auxiliary reaction kettle, the second auxiliary reaction kettle, the third auxiliary reaction kettle, the fourth auxiliary reaction kettle, the fifth auxiliary reaction kettle and the sixth auxiliary reaction kettle, the pre-reaction section and the main reaction section are arranged, the continuity and controllability of the chlorination reaction are achieved through the multi-stage series connection type design, the stability and safety of the reaction are guaranteed, and the production cost is reduced. The utilization rate of chlorine is increased, the generation of byproducts is reduced, and the environmental pollution is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of chlorinated paraffin production, and in particular to a multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method. Background Art

[0002] Chlorinated paraffin is a chlorinated derivative of paraffin hydrocarbons. It has the advantages of low volatility, flame retardancy, good electrical insulation, and low price. It can be used as a flame retardant and auxiliary plasticizer for polyvinyl chloride. It is widely used in the production of cable materials, floor materials, hoses, artificial leather, rubber and other products. It is also used as an additive for polyurethane waterproof coatings, polyurethane plastic tracks, lubricating oils, etc.

[0003] In the process of chlorination of liquid paraffin, the traditional chlorination reaction method has the problems of low chlorine utilization rate, many by-products and serious environmental pollution.

[0004] To this end, we propose a multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method. Summary of the invention

[0005] The present invention mainly solves the technical problems existing in the above-mentioned prior art and provides a multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a multi-stage series liquid paraffin chlorination reaction and chlorine recovery system, including a pre-reaction section, a main reaction section and a semi-finished product kettle, the pre-reaction section includes a continuous feeding device, a liquid paraffin delivery pipeline, No. 1 secondary reaction kettle, No. 2 secondary reaction kettle, No. 3 secondary reaction kettle, No. 4 secondary reaction kettle, No. 5 secondary reaction kettle, No. 6 secondary reaction kettle, a secondary jacket circulating water cooling device, a secondary circulating water pipe, an exhaust gas treatment device and an exhaust gas pipeline, No. 1 secondary reaction kettle, No. 2 secondary reaction kettle, No. 3 secondary reaction kettle, No. 4 secondary reaction kettle, No. 5 secondary reaction kettle, No. 6 secondary reaction kettle, a secondary jacket circulating water cooling device, a secondary circulating water pipe, an exhaust gas treatment device and an exhaust gas pipeline, Ultraviolet lamps are installed in auxiliary reactor No. 1, auxiliary reactor No. 2, auxiliary reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6. The main reaction section includes main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6, chlorine gas distribution cylinder, chlorine gas pipeline, hydrogen chloride and chlorine gas delivery pipeline, main jacket circulating water cooling device and main circulating water pipe. Ultraviolet lamps are installed in main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6.

[0007] Preferably, the continuous feeding device is connected to the No. 1 secondary reaction kettle via a liquid paraffin delivery pipeline.

[0008] Preferably, the No. 1 secondary reaction kettle, the No. 2 secondary reaction kettle, the No. 3 secondary reaction kettle, the No. 4 secondary reaction kettle, the No. 5 secondary reaction kettle and the No. 6 secondary reaction kettle are respectively connected by a liquid paraffin delivery pipeline.

[0009] Preferably, the secondary jacket circulating water cooling device is respectively connected to secondary reactor No. 1, secondary reactor No. 2, secondary reactor No. 3, secondary reactor No. 4, secondary reactor No. 5 and secondary reactor No. 6 through secondary circulating water pipes.

[0010] Preferably, the No. 1 auxiliary reactor, No. 2 auxiliary reactor, No. 3 auxiliary reactor, No. 4 auxiliary reactor, No. 5 auxiliary reactor and No. 6 auxiliary reactor are respectively connected to the exhaust gas treatment device through the exhaust gas pipeline.

[0011] Preferably, the semi-finished product kettle, main reactor No. 6, main reactor No. 5, main reactor No. 4, main reactor No. 3, main reactor No. 2 and main reactor No. 1 are respectively connected by liquid paraffin delivery pipelines.

[0012] Preferably, the No. 1 main reactor is connected to the No. 6 sub-reactor via a liquid paraffin delivery pipeline.

[0013] Preferably, the chlorine gas distribution cylinder is connected to main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 respectively through chlorine pipelines.

[0014] Preferably, the No. 6 main reactor, the No. 5 main reactor, the No. 4 main reactor, the No. 3 main reactor, the No. 2 main reactor and the No. 1 main reactor are connected via hydrogen chloride and chlorine gas delivery pipelines respectively.

[0015] Preferably, the main reactor No. 1 is connected to the sub-reactor No. 1, sub-reactor No. 2, sub-reactor No. 3, sub-reactor No. 4, sub-reactor No. 5 and sub-reactor No. 6 respectively through hydrogen chloride and chlorine gas delivery pipelines.

[0016] Preferably, the main jacket circulating water cooling device is respectively connected to main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 through the main circulating water pipe.

[0017] A multi-stage series liquid paraffin chlorination reaction and chlorine recovery method, comprising the above-mentioned multi-stage series liquid paraffin chlorination reaction and chlorine recovery system, specifically comprising the following steps:

[0018] The first step: pre-reaction stage: the continuous feeding device continuously transports the liquid paraffin to the No. 1 sub-reactor through the liquid paraffin delivery pipeline, the hydrogen chloride and a trace of unreacted chlorine generated in the main reaction section enter the No. 1 sub-reactor in the pre-reaction section through the hydrogen chloride and chlorine delivery pipelines, the ultraviolet lamp in the No. 1 sub-reactor is turned on, so that the chlorine and the liquid paraffin undergo a preliminary photocatalytic reaction, and the reaction process is an exothermic reaction. The secondary jacket circulating water cooling device inputs cooling water into the No. 1 sub-reactor through the secondary circulating water pipe to cool it, and the liquid paraffin after the preliminary photocatalytic reaction enters the No. 2 sub-reactor, the No. 3 sub-reactor, the No. 4 sub-reactor, the No. 5 sub-reactor and the No. 6 sub-reactor in turn through the overflow method for pre-reaction treatment;

[0019] Step 2: Main reaction stage: The liquid paraffin after pre-reaction treatment in No. 6 auxiliary reactor enters No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor in turn through overflow mode, and the chlorine gas distribution cylinder is opened to transport chlorine through the chlorine pipeline into No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor in turn, and the No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor are opened in turn. The ultraviolet lamps in the reactor, the No. 5 main reactor and the No. 6 main reactor make the chlorine gas and the liquid paraffin undergo a preliminary photocatalytic reaction. The reaction process is an exothermic reaction. The main jacket circulating water cooling device sequentially inputs cooling water into the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor through the main circulating water pipe to cool them to ensure that the reaction temperature is controlled at 85°C-110°C. The liquid paraffin in the No. 6 main reactor that has completed the reaction flows into the semi-finished product reactor by overflow;

[0020] Step 3: Chlorine recovery and treatment: The hydrogen chloride and trace unreacted chlorine produced by the reaction of main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 enter the pre-reaction section to further improve the utilization rate of chlorine. Finally, the hydrogen chloride and trace unreacted chlorine are discharged to the waste gas treatment device through the waste gas pipeline for treatment to prevent air pollution.

[0021] The present invention provides a multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method, which has the following beneficial effects:

[0022] 1. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method, by setting a pre-reaction section and a main reaction section, realizes the continuity and controllability of the chlorination reaction through a multi-stage series design, ensures the stability and safety of the reaction, improves the utilization rate of chlorine, reduces the generation of by-products, and effectively reduces environmental pollution.

[0023] 2. This multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method, by setting up ultraviolet lamps, uses ultraviolet lamps to carry out photocatalytic reactions, accelerates the reaction rate of chlorine and liquid paraffin, and improves production efficiency.

[0024] 3. This multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method effectively controls the temperature during the reaction process, avoids overheating, and ensures the smooth progress of the reaction through the use of a secondary jacket circulating water cooling device and a main jacket circulating water cooling device.

[0025] 4. This multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method, through the introduction of waste gas treatment equipment, ensures that hydrogen chloride and unreacted chlorine in the waste gas are reasonably recovered and treated, avoiding pollution to the environment.

[0026] 5. This multi-stage series liquid paraffin chlorination reaction and chlorine recovery system and method achieves efficient material flow and reaction uniformity through optimized design of the conveying pipeline and the configuration of the reactor, thereby improving the quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the system module of the present invention. DETAILED DESCRIPTION

[0028] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0029] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] In the description of the embodiments of the present invention, it should be noted that the terms "center", "upper", "lower", "inner", "outer", "side", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invented product is usually placed when in use, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0032] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Embodiment 1: A multi-stage series liquid paraffin chlorination reaction and chlorine recovery system, such as Figure 1 As shown, it includes a pre-reaction section, a main reaction section and a semi-finished product kettle. The pre-reaction section includes a continuous feeding device, a liquid paraffin delivery pipeline, a No. 1 side reactor, a No. 2 side reactor, a No. 3 side reactor, a No. 4 side reactor, a No. 5 side reactor, a No. 6 side reactor, a secondary jacket circulating water cooling device, a secondary circulating water pipe, an exhaust gas treatment device and an exhaust gas pipeline. The No. 1 side reactor, the No. 2 side reactor, the No. 3 side reactor, the No. 4 side reactor, the No. 5 side reactor and the No. 6 side reactor are all equipped with ultraviolet lamps. The feeding device is connected to the No. 1 sub-reactor through a liquid paraffin delivery pipeline, and the No. 1 sub-reactor, No. 2 sub-reactor, No. 3 sub-reactor, No. 4 sub-reactor, No. 5 sub-reactor and No. 6 sub-reactor are respectively connected through liquid paraffin delivery pipelines. By setting up a pre-reaction section and a main reaction section and through a multi-stage series design, the continuity and controllability of the chlorination reaction are achieved, the stability and safety of the reaction are guaranteed, the utilization rate of chlorine is improved, the generation of by-products is reduced, and environmental pollution is effectively reduced.

[0035] Embodiment 2: Based on Embodiment 1, Figure 1 As shown, the auxiliary jacket circulating water cooling device is connected to auxiliary reactor No. 1, auxiliary reactor No. 2, auxiliary reactor No. 3, auxiliary reactor No. 4, auxiliary reactor No. 5 and auxiliary reactor No. 6 through auxiliary circulating water pipes, and auxiliary reactor No. 1, auxiliary reactor No. 2, auxiliary reactor No. 3, auxiliary reactor No. 4, auxiliary reactor No. 5 and auxiliary reactor No. 6 are respectively connected to the exhaust gas treatment device through exhaust gas pipes. The main reaction section includes main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5, main reactor No. 6, chlorine gas distribution cylinder, chlorine pipeline, hydrogen chloride and chlorine gas delivery pipeline, main jacket circulating water cooling device and main circulating water pipe. By arranging ultraviolet lamps, ultraviolet lamps are used for light catalytic reaction, so as to accelerate the reaction rate of chlorine and liquid paraffin and improve production efficiency.

[0036] Embodiment 3: Based on Embodiment 1 and Embodiment 2, Figure 1 As shown, main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 are all provided with ultraviolet lamps, the semi-finished product reactor, main reactor No. 6, main reactor No. 5, main reactor No. 4, main reactor No. 3, main reactor No. 2 and main reactor No. 1 are respectively connected through liquid paraffin delivery pipelines, main reactor No. 1 is connected to auxiliary reactor No. 6 through liquid paraffin delivery pipeline, and chlorine gas distribution cylinders are respectively connected to main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 through chlorine pipelines, and the temperature in the reaction process is effectively controlled by using auxiliary jacket circulating water cooling devices and main jacket circulating water cooling devices, avoiding overheating and ensuring the smooth progress of the reaction.

[0037] Embodiment 4: Based on Embodiment 1, Embodiment 2 and Embodiment 3, Figure 1 As shown, main reactor No. 6, main reactor No. 5, main reactor No. 4, main reactor No. 3, main reactor No. 2 and main reactor No. 1 are connected respectively through hydrogen chloride and chlorine delivery pipelines, main reactor No. 1 is connected to sub-reactor No. 1, sub-reactor No. 2, sub-reactor No. 3, sub-reactor No. 4, sub-reactor No. 5 and sub-reactor No. 6 through hydrogen chloride and chlorine delivery pipelines, and the main jacket circulating water cooling device is connected to main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 through the main circulating water pipe. The introduction of the exhaust gas treatment device ensures that hydrogen chloride and unreacted chlorine in the exhaust gas are reasonably recovered and treated, thereby avoiding pollution to the environment.

[0038] Embodiment 5: A multi-stage series liquid paraffin chlorination reaction and chlorine recovery method, such as Figure 1As shown, the multi-stage series liquid paraffin chlorination reaction and chlorine recovery system includes the following steps: the first step: pre-reaction stage: the continuous feeding device continuously transports the liquid paraffin to the No. 1 side reaction kettle through the liquid paraffin delivery pipeline, the hydrogen chloride and a trace of unreacted chlorine generated in the main reaction section enter the No. 1 side reaction kettle in the pre-reaction section through the hydrogen chloride and chlorine delivery pipelines, the ultraviolet lamp in the No. 1 side reaction kettle is turned on, and the chlorine and the liquid paraffin undergo a preliminary photocatalytic reaction. The reaction process is an exothermic reaction, and the secondary jacket circulating water cooling device passes cooling water through the secondary jacket circulating water cooling device. The liquid paraffin after the preliminary photocatalytic reaction is input into the No. 1 secondary reactor for cooling. The liquid paraffin after the preliminary photocatalytic reaction is sequentially fed into the No. 2 secondary reactor, the No. 3 secondary reactor, the No. 4 secondary reactor, the No. 5 secondary reactor and the No. 6 secondary reactor for pre-reaction treatment by overflow. The second step: the main reaction stage: the liquid paraffin after the pre-reaction treatment of the No. 6 secondary reactor is sequentially fed into the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor by overflow. The chlorine gas distribution cylinder is opened to pass the chlorine gas through the chlorine gas pipeline. The cooling water is transported into the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor, and the ultraviolet lamps in the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor are turned on in sequence to make the chlorine gas and the liquid paraffin undergo a preliminary photocatalytic reaction. The reaction process is an exothermic reaction. The main jacket circulating water cooling device inputs the cooling water into the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor in sequence through the main circulating water pipe. The main reactor is cooled to ensure that the reaction temperature is controlled at 85℃-110℃. The liquid paraffin in the No. 6 main reactor flows into the semi-finished product reactor through overflow. The third step: chlorine recovery and treatment: the hydrogen chloride and trace unreacted chlorine produced by the reaction of the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor enter the pre-reaction section to further improve the utilization rate of chlorine. Finally, the hydrogen chloride and trace unreacted chlorine are discharged to the waste gas treatment device through the waste gas pipeline for treatment to prevent air pollution. Through the optimized design of the conveying pipeline and the configuration of the reactor, the efficient flow of materials and the uniformity of the reaction are achieved, and the quality of the product is improved.

[0039] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A multi-stage series liquid paraffin chlorination reaction and chlorine recovery system, characterized in that: The invention comprises a pre-reaction section, a main reaction section and a semi-finished product kettle. The pre-reaction section comprises a continuous feeding device, a liquid paraffin conveying pipeline, No. 1 sub-reactor, No. 2 sub-reactor, No. 3 sub-reactor, No. 4 sub-reactor, No. 5 sub-reactor, No. 6 sub-reactor, a sub-jacket circulating water cooling device, a sub-circulating water pipe, an exhaust gas treatment device and an exhaust gas pipeline. Ultraviolet lamps are arranged in No. 1 sub-reactor, No. 2 sub-reactor, No. 3 sub-reactor, No. 4 sub-reactor, No. 5 sub-reactor and No. 6 sub-reactor. The continuous feeding device is connected to No. 1 sub-reactor through a liquid paraffin conveying pipeline. No. 1 sub-reactor, No. 2 sub-reactor, No. 3 sub-reactor, No. 4 sub-reactor, No. 5 sub-reactor and No. 6 sub-reactor The No. 6 auxiliary reactors are connected to each other through liquid paraffin delivery pipelines. The main reaction section includes No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor, No. 6 main reactor, chlorine gas distribution cylinder, chlorine pipeline, hydrogen chloride and chlorine delivery pipeline, main jacket circulating water cooling device and main circulating water pipe. Ultraviolet lamps are installed in No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor. The semi-finished product reactor, No. 6 main reactor, No. 5 main reactor, No. 4 main reactor, No. 3 main reactor, No. 2 main reactor and No. 1 main reactor are connected to each other through liquid paraffin delivery pipelines.

2. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The secondary jacket circulating water cooling device is respectively connected to secondary reactor No. 1, secondary reactor No. 2, secondary reactor No. 3, secondary reactor No. 4, secondary reactor No. 5 and secondary reactor No. 6 through secondary circulating water pipes.

3. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The No. 1 auxiliary reactor, No. 2 auxiliary reactor, No. 3 auxiliary reactor, No. 4 auxiliary reactor, No. 5 auxiliary reactor and No. 6 auxiliary reactor are respectively connected to the exhaust gas treatment device through the exhaust gas pipeline.

4. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The No. 1 main reactor is connected to the No. 6 sub-reactor through a liquid paraffin delivery pipeline.

5. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The chlorine gas distribution cylinder is respectively connected with the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor through a chlorine gas pipeline.

6. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The No. 6 main reactor, the No. 5 main reactor, the No. 4 main reactor, the No. 3 main reactor, the No. 2 main reactor and the No. 1 main reactor are respectively connected through hydrogen chloride and chlorine gas delivery pipelines.

7. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The No. 1 main reactor is connected to the No. 1 sub-reactor, No. 2 sub-reactor, No. 3 sub-reactor, No. 4 sub-reactor, No. 5 sub-reactor and No. 6 sub-reactor respectively through hydrogen chloride and chlorine gas delivery pipelines.

8. The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system according to claim 1, characterized in that: The main jacket circulating water cooling device is respectively connected to the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor through the main circulating water pipe.

9. A multi-stage series liquid paraffin chlorination reaction and chlorine recovery method, characterized in that: The multi-stage series liquid paraffin chlorination reaction and chlorine recovery system comprising any one of claims 1 to 8 specifically comprises the following steps: The first step: pre-reaction stage: the continuous feeding device continuously transports the liquid paraffin to the No. 1 sub-reactor through the liquid paraffin delivery pipeline, the hydrogen chloride and a trace of unreacted chlorine generated in the main reaction section enter the No. 1 sub-reactor in the pre-reaction section through the hydrogen chloride and chlorine delivery pipelines, the ultraviolet lamp in the No. 1 sub-reactor is turned on, so that the chlorine and the liquid paraffin undergo a preliminary photocatalytic reaction, and the reaction process is an exothermic reaction. The secondary jacket circulating water cooling device inputs cooling water into the No. 1 sub-reactor through the secondary circulating water pipe to cool it, and the liquid paraffin after the preliminary photocatalytic reaction enters the No. 2 sub-reactor, the No. 3 sub-reactor, the No. 4 sub-reactor, the No. 5 sub-reactor and the No. 6 sub-reactor in turn through the overflow method for pre-reaction treatment; Step 2: Main reaction stage: The liquid paraffin after pre-reaction treatment in No. 6 auxiliary reactor enters No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor in turn through overflow mode, and the chlorine gas distribution cylinder is opened to transport chlorine through the chlorine pipeline into No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor in turn, and the No. 1 main reactor, No. 2 main reactor, No. 3 main reactor, No. 4 main reactor, No. 5 main reactor and No. 6 main reactor are opened in turn. The ultraviolet lamps in the reactor, the No. 5 main reactor and the No. 6 main reactor make the chlorine gas and the liquid paraffin undergo a preliminary photocatalytic reaction. The reaction process is an exothermic reaction. The main jacket circulating water cooling device sequentially inputs cooling water into the No. 1 main reactor, the No. 2 main reactor, the No. 3 main reactor, the No. 4 main reactor, the No. 5 main reactor and the No. 6 main reactor through the main circulating water pipe to cool them to ensure that the reaction temperature is controlled at 85°C-110°C. The liquid paraffin in the No. 6 main reactor that has completed the reaction flows into the semi-finished product reactor by overflow; Step 3: Chlorine recovery and treatment: The hydrogen chloride and trace unreacted chlorine produced by the reaction of main reactor No. 1, main reactor No. 2, main reactor No. 3, main reactor No. 4, main reactor No. 5 and main reactor No. 6 enter the pre-reaction section to further improve the utilization rate of chlorine. Finally, the hydrogen chloride and trace unreacted chlorine are discharged to the waste gas treatment device through the waste gas pipeline for treatment to prevent air pollution.

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