A spray-type multi-stage tower-type continuous production apparatus and method for chlorinated paraffin.

Abstract

This invention belongs to the technical field of paraffin wax production equipment, and relates to an apparatus and method for continuous production of chlorinated paraffin wax using a multi-stage spray tower. The apparatus includes a spray tower body, with a tail gas outlet and a demister at the top. Several reaction sections are located below the tail gas outlet, with a demister at the top of the uppermost reaction section. Each reaction section has a spray device for uniform liquid spraying, a light source for catalysis, and a gas distributor for uniform gas distribution at the bottom. Each reaction section has a heat exchange device and a liquid storage device at the bottom. The reaction sections are connected to each other via external gas-phase and external liquid-phase circulation pipelines. Compared with existing processes, this invention offers a larger mass transfer area between chlorine and paraffin oil, a faster reaction rate, and controllable reaction depth, demonstrating significant potential for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology, specifically relating to an apparatus and method for continuous production of chlorinated paraffin using a multi-stage spray tower. Background Technology

[0002] Chlorinated paraffins can be used as flame retardants in various products, including but not limited to the plastics, rubber, and fiber industries, as well as as plasticizers, surface treatment agents, modifiers, anti-wear agents, mildew inhibitors, waterproofing agents, and ink additives. They are widely used in the production of cable materials, flooring materials, hoses, artificial leather, rubber products, and more.

[0003] Currently, industrial production methods for chlorinated paraffin include thermal chlorination, catalytic chlorination, and photochlorination. Regardless of the method used, common problems include high reaction temperatures, long reaction times, low chlorine utilization, significant chlorine leakage in the tail gas, and inconsistent product color. Traditional thermocatalytic chlorination processes for paraffin mostly employ batch or tower-type bubble reactors. The advent of photocatalytic production has significantly shortened the production cycle because photocatalysis accelerates chain initiation and macroscopic reaction rates. However, current photocatalytic reactions still utilize bubble reactors, which suffer from poor gas-liquid dispersion, shifting macroscopic reaction rate control from reaction rate control to mass transfer rate control. To further improve reaction rates and production efficiency, research is needed on novel photocatalytic chlorination paraffin reactors.

[0004] For example, patent application CN115353907A discloses a reaction tower for preparing chlorinated paraffin. The process uses a lifting ring and relies on density differences to achieve automatic separation of paraffins with different chlorination depths. However, the reaction speed is slow, the production cycle is long, and the reactor contains a rotating stirring tube, resulting in poor production stability.

[0005] For example, patent application CN109022035A discloses a high-efficiency production device and method for chlorinated paraffin. This method uses a method of mixing chlorine gas and paraffin oil outside the reaction vessel, and then the mixed material enters the reaction vessel to react, so as to achieve the purpose of fully mixing chlorine gas and paraffin oil. However, this process does not solve the problem of timely exhaust gas discharge and long production cycle. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a device and method for continuous production of chlorinated paraffin using a multi-stage spray tower. Compared with existing processes, this method features a large gas-liquid phase contact area, high mass transfer efficiency, short reaction time, high chlorine utilization rate, and controllable reaction depth.

[0007] The specific technical solution of the present invention is as follows:

[0008] A multi-stage spray tower-type continuous production apparatus for chlorinated paraffin includes a spray tower body. The top of the spray tower body is provided with a tail gas outlet and a demister. Several reaction sections are provided below the tail gas outlet, and a demister is provided at the top of the uppermost reaction section. Each reaction section is provided with a spray device for uniformly spraying liquid, a light source for catalysis, and a gas distributor for uniformly distributing gas at the bottom of each reaction section. Each reaction section is provided with a heat exchange device and a liquid storage device at the bottom. The reaction sections are connected to each other through a gas phase external circulation pipeline and a liquid phase external circulation pipeline.

[0009] Furthermore, the liquid injection direction of the spray device is consistent with the gas injection direction of the gas distributor, and the liquid flow direction in the reaction section is opposite to the gas flow direction.

[0010] Furthermore, the light sources at the top of each reaction section are evenly distributed between the spray device and the gas distribution device. The illuminance of the light sources is 1-5 kW / m². 3 .

[0011] Furthermore, the heat exchange devices at the bottom of each reaction section are immersed in the liquid stored in the liquid storage device.

[0012] Furthermore, the liquid-phase external circulation pipeline between each reaction section is led out from the liquid storage device, and after passing through an external heat exchanger and a transfer pump, it is divided into two streams: one returns to the spray device of this section, and the other enters the spray device of the next section. The gas-phase external circulation pipeline between each reaction section is led out from the top of the next stage reaction section and connected to the gas distributor of the current stage reaction section. The pipeline is equipped with gas inlet and outlet branch pipelines in the middle.

[0013] Based on the above-mentioned spray-type multi-stage tower-type continuous production apparatus for chlorinated paraffin, the space between the spray device at the top of the reaction section and the gas distributor at the bottom of the reaction section is designated as the reaction space. By controlling the height-to-diameter ratio of the reaction space to be 0.1:1 to 4:1, the reaction rate and depth are controlled. This production method includes the following processes:

[0014] Paraffin sprayed downwards from the spray device at the top of the reaction section reacts with chlorine gas sprayed from the gas distributor at the bottom of the reaction section. After the reaction, the liquid enters the liquid storage device, where the temperature is controlled by the internal heat exchanger.

[0015] The chlorinated paraffin oil in the reaction section is drawn from the bottom of the liquid storage unit, heats up through an external heat exchanger, and then enters the paraffin oil transfer pump. After pressurization, it is divided into two streams: one stream of chlorinated paraffin oil mixes with fresh paraffin oil and returns to the spray device in this stage of the reaction section; the other stream of chlorinated paraffin oil enters the spray device in the next stage of the reaction section. Light sources are installed inside or outside each reaction section of the spray tower to perform photocatalysis on the reaction.

[0016] Furthermore, the fresh paraffin oil is C 10 -C30 The liquid paraffin; the temperature of each reaction section in the spray tower is controlled at 70-110℃; the pressure in the spray tower is controlled at 0.08-0.12MPa.

[0017] Furthermore, the feature is that the ratio of the mass flow rate of paraffin oil to the mass flow rate of chlorine gas in the spray tower is 1:1-6; the reflux ratio of each reaction section of the spray tower is 20-60; and the chlorine content of the material in each reaction section of the spray tower maintains a gradient of 5-30%.

[0018] Furthermore, each reaction section inside or outside the spray tower is equipped with a light source, which is a common light source or an ultraviolet light source; the light source is a scattered light source or a strip light source.

[0019] Furthermore, the height-to-diameter ratio of the reaction space between the spray device at the top of the reaction section and the gas distributor at the bottom of the reaction section is set to 0.1:1 to 4:1. The residence time of the material in the spray tower is 0.1-3 hours.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. The spray multi-stage tower-type continuous production device for chlorinated paraffin of the present invention breaks away from the previous idea of ​​using the liquid phase of paraffin as the continuous phase, and uses the gas phase of chlorine as the continuous phase, thereby increasing the contact area between the gas and liquid phases and accelerating the reaction rate.

[0022] 2. The present invention incorporates a wax oil spraying device and a gas distributor, which makes the reaction between chlorine and paraffin more uniform, prevents excessive local heating, accelerates the reaction rate, and prevents the formation of black material.

[0023] 3. The production method of chlorinated paraffin by spraying multi-stage tower in this invention has found suitable height-to-diameter ratio, reflux ratio, temperature, pressure and light conditions by screening reaction space, reflux ratio, temperature, pressure and light conditions. The effective height of the reaction section and the combination of reflux ratio and other conditions are cleverly set to improve the reaction speed, control the reaction depth, avoid the generation of black material and achieve the effect of controllable reaction depth.

[0024] In past production practices, a common problem has been insufficient or excessive reaction, resulting in black residue. This is the reason why current chlorinated paraffin production processes have been unable to achieve a breakthrough. This invention proposes and verifies a continuous multi-stage spray tower method for producing chlorinated paraffin, which, through the selection of combinations of reaction phase reversal, reaction equipment type, light, temperature, pressure, reflux ratio, and height-to-diameter ratio, fundamentally solves the problems of insufficient or excessive reaction in current chlorinated paraffin production technology. The produced 52# product meets the domestic high-quality product requirements. This invention is innovative in improving product quality, increasing output, simplifying processes, reducing investment, and enhancing safety. This invention primarily solves technical problems such as shortened reaction time, high chlorine utilization, controllable reaction depth, convenient operation, simplified processes, and reduced investment.

[0025] 4. The present invention adds a tail gas extraction pipeline between adjacent spray layers to extract the tail gas generated by the reaction in a timely manner, which helps to accelerate the reaction. Attached Figure Description

[0026] Figure 1 This is the three-layer spray-type high-efficiency production device for chlorinated paraffin in Embodiment 1 of the present invention;

[0027] Figure 2 This is the three-layer spray-type high-efficiency production device for chlorinated paraffin in Embodiment 2 of the present invention;

[0028] Figure 3 This refers to the three-layer spray-type high-efficiency production device for chlorinated paraffin in Embodiment 3 of the present invention;

[0029] In the diagram, 1, 19, 21 - transfer pumps; 2, 18, 20 - external heat exchangers; 3, 17, 22 - internal heat exchangers; 4, 16, 23 - liquid storage devices; 5 - demister; 6 - tail gas outlet; 7, 10, 13 - spray devices; 8, 11, 14 - light sources; 9, 12, 15 - gas distributors; 101, 102, 111, 112 - chlorinated paraffin oil; 103 - fresh paraffin oil; 105, 107, 109 - chlorine gas; 104, 106, 108 - reaction tail gas; 110 - chlorinated paraffin oil. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] like Figure 1As shown, the device used in this invention consists of several reaction sections. It mainly includes a transfer pump (1, 19, 21), an external heat exchanger (2, 18, 20), an internal heat exchanger (3, 17, 22), a liquid storage device (4, 16, 23), a demister (5), a tail gas outlet (6), a wax oil spraying device (7, 10, 13), a light source (8, 11, 14), a gas distributor (9, 12, 15), and other auxiliary equipment.

[0032] In the reaction section at the top of the spray tower, fresh paraffin oil (103) and chlorinated paraffin oil (102) are mixed and uniformly sprayed into the wax oil spraying device (7) at the top of the spray tower. Chlorine gas sprayed from the gas distributor (9) generates chlorine free radicals under the catalysis of the light source (8), which react with the droplets of chlorinated paraffin oil sprayed by the wax oil spraying device (7). After the reaction, the gas phase is discharged into the tail gas treatment system through the tail gas outlet (6) after the chlorinated paraffin oil mist droplets in the gas phase are removed by the demister (5). After the reaction, the liquid phase is heated by the internal heat exchanger (3) and the external heat exchanger (2), and after being pressurized by the transfer pump (1), part of the chlorinated paraffin oil (102) is mixed with the fresh paraffin oil (103) and returned to the tower, while the remaining chlorinated paraffin oil (101) enters the lower reaction section.

[0033] In the reaction section of the spray tower, chlorinated paraffin oil (101) from the previous reaction section and chlorinated paraffin oil (113) from the current transfer pump (21) are mixed and then sprayed evenly into the wax oil spraying device (10). Chlorine gas sprayed from the gas distributor (12) generates chlorine free radicals under the catalysis of the light source (11), which react with the droplets of chlorinated paraffin oil sprayed by the wax oil spraying device (10). The gas phase after the reaction enters the gas distributor (9) of the previous reaction section and reacts again with the chlorinated paraffin oil with a low chlorination depth. The liquid phase after the reaction is heated by the internal heat exchanger (22) and the external heat exchanger (20), and after being pressurized by the transfer pump (21), part of the chlorinated paraffin oil (113) is mixed with the chlorinated paraffin oil (101) from the previous layer and returned to the tower, while the remaining chlorinated paraffin oil (112) enters the next reaction section.

[0034] In the reaction section at the bottom of the spray tower, chlorinated paraffin oil (112) from the previous reaction section and chlorinated paraffin oil (111) from the current transfer pump (19) are mixed and then sprayed evenly into the wax oil spraying device (13). Chlorine gas sprayed from the gas distributor (15) generates chlorine free radicals under the catalysis of the light source (14), which react with the droplets of chlorinated paraffin oil sprayed by the wax oil spraying device (13). The gas phase after the reaction enters the gas distributor (12) of the previous reaction section and reacts again with the paraffin oil with a low chlorination depth. The liquid phase after the reaction is heated by the internal heat exchanger (17) and the external heat exchanger (18), and after being pressurized by the transfer pump (19), part of the chlorinated paraffin oil (111) is mixed with the chlorinated paraffin oil (112) from the upper layer and returned to the tower, while the remaining chlorinated paraffin oil (110) exits the device.

[0035] In the operation of this invention, the following components are treated with anti-corrosion measures on their surfaces in contact with the material: the delivery pump (1, 19, 21), the external heat exchanger (2, 18, 20), the internal heat exchanger (3, 17, 22), the liquid storage device (4, 16, 23), the demister (5), the exhaust gas outlet (6), the wax oil spraying device (7, 10, 13), the light source (8, 11, 14), the gas distributor (9, 12, 15), and other auxiliary equipment. In this invention, the fresh paraffin oil (103) in the logistics process is C 10 -C 30 The liquid paraffin is used for the following processes: Chlorine gas (105, 107, 109) is industrial chlorine; Chlorinated paraffin oil (101, 102) in the top reaction section of the tower is low-chlorinated paraffin oil with a chlorination depth between 1% and 30%; Chlorinated paraffin oil (112, 113) in the middle section of the tower is high-chlorinated paraffin oil with a chlorination depth between 20% and 50%; Chlorinated paraffin oil (110) at the bottom of the tower is the finished chlorinated paraffin with a chlorination depth of 52%.

[0036] The technical solution of the present invention will be described in detail below through specific embodiments.

[0037] Example 1:

[0038] A three-layer spray-type high-efficiency production device for chlorinated paraffin, the specific process is as follows: Figure 1 As shown.

[0039] The spray tower has a tail gas outlet (6) at the top, and a demister (5) is located below the tail gas outlet. Below the demister (5), there are three spray reaction sections from top to bottom. The upper part of each reaction section is equipped with a wax oil spraying device (7, 10, 13) to ensure uniform spraying of chlorinated paraffin oil, a gas distributor (9, 12, 15) to ensure uniform gas distribution, and a light source (8, 11, 14) for catalysis. The lower part of each reaction section is equipped with an internal heat exchanger (3, 17, 22) and a liquid storage device (4, 16, 23). The reaction sections are connected by gas-phase and liquid-phase external circulation pipelines.

[0040] The gas distributors (9, 12, 15) at the top of the reaction section are located below the wax oil spraying devices (7, 10, 13). The wax oil spraying devices (7, 10, 13) spray downwards with a chain length of C. 10 -C 20 The chlorinated paraffin oil has gas distributors (9, 12, 15) with downward-facing openings. The liquid injection direction is the same as the gas injection direction, while the liquid flow direction is opposite to the gas flow direction. The light sources (8, 11, 14) at the top of the reaction section are scattered light sources evenly distributed between the wax oil spraying devices (7, 10, 13) and the gas distributors (9, 12, 15). The light sources (8, 11, 14) are ultraviolet light sources, illuminating the area between the wax oil spraying devices (7, 10, 13) and the gas distributors (9, 12, 15) in the reaction section through the tower's viewing windows.

[0041] The internal heat exchangers (3, 17, 22) at the bottom of the reaction section are immersed in the liquid stored in the liquid storage device (4, 16, 23). The internal heat exchangers (3, 17, 22) are coil-type heat exchangers, with circulating water flowing inside the coils and enamel coating on the outside of the coils.

[0042] The ratio of the mass flow rate of paraffin oil to the mass flow rate of chlorine gas in the spray tower is 1:2. The reflux ratio of each reactor section is 35, the residence time is 1.3 hours, and the light intensity is the same. The reaction temperature, reaction pressure, and chlorination depth of the material at the outlet of the liquid storage device are different. In the first reaction section, the light intensity is 2kW / m3, the reaction temperature is 90℃, the reaction pressure is 0.08MPa, and the chlorination depth of the material at the outlet of the liquid storage device (4) is 5%. In the second reaction section, the light intensity is 2kW / m3, the reaction temperature is 95℃, the reaction pressure is 0.1MPa, and the chlorination depth of the material at the outlet of the liquid storage device (16) is 25%. In the third reaction section, the light intensity is 2kW / m3, the reaction temperature is 95℃, the reaction pressure is 0.1MPa, and the chlorination depth of the material at the outlet of the liquid storage device (16) is 25%. 3 The reaction temperature is 100℃, the reaction pressure is 0.12MPa, and the chlorination depth of the material at the outlet of the liquid storage device (23) is 50%. The height-to-diameter ratio of the reaction space between the spray device (7) at the top of the reaction section and the gas distributor (9) at the bottom of the reaction section is set to 0.2:1.

[0043] The liquid phase between adjacent reaction sections is connected by an external liquid phase circulation pipeline, and the pipeline is equipped with an external heat preservation device.

[0044] a. The chlorinated paraffin oil in the first reaction section is drawn from the bottom of the liquid storage device (4), and after heat exchange by the external heat exchanger (2), it enters the transfer pump (1). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (102) is mixed with fresh paraffin oil (103) and returned to the spray device (7) of the first reaction section. The other stream of chlorinated paraffin oil (101) enters the spray device (10) of the second reaction section.

[0045] b. The chlorinated paraffin oil in the second reaction section is drawn from the bottom of the liquid storage device (23), and after heat exchange by the external heat exchanger (20), it enters the transfer pump (21). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (113) is mixed with the chlorinated paraffin oil (101) from the first reaction section and returns to the spray device (7) of the second reaction section. The other stream of chlorinated paraffin oil (112) enters the spray device (13) of the third reaction section.

[0046] c. The chlorinated paraffin oil in the third reaction section is drawn from the bottom of the liquid storage device (16), and after heat exchange by the external heat exchanger (18), it enters the transfer pump (19), and after being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (111) is mixed with the chlorinated paraffin oil (112) from the second reaction section and returns to the spray device (13) of the third reaction section. The other stream of chlorinated paraffin oil (110) exits the device.

[0047] The gas phase between adjacent reaction sections is connected by an external gas phase circulation pipeline, which is insulated. Fresh chlorine gas (109) is introduced from the bottom of the third reaction section. The tail gas after the reaction is extracted from the top of the reaction section and connected to the gas distributor (12) of the second reaction section through a pipeline. The connecting pipeline does not extract the tail gas (108) and replenishes a certain amount of chlorine gas (107). The tail gas of the second reaction section is extracted from the top of the second reaction section and connected to the gas distributor (9) of the first reaction section through a pipeline. The connecting pipeline does not extract the tail gas (106) and does not replenish chlorine gas (105). The tail gas of the first reaction section is treated by removing the entrained wax oil through the demister (5) and then exits through the tail gas outlet (6) into the tail gas treatment system.

[0048] The quality of chlorinated paraffin oil (110) and chlorinated paraffin oil (111) both met the requirements of GB / T 40263-2021 for the determination of short-chain chlorinated paraffins.

[0049] The flow rate composition of each liquid phase stream is shown in Table 1.

[0050] Table 1. Flow rates and chlorination depths of each liquid phase stream in Example 1

[0051]

[0052]

[0053] The flow rate composition of each gas phase stream is shown in Table 2.

[0054] Table 2. Gas phase inlet and outlet flow rates and composition in Example 1

[0055]

[0056] The operating conditions for each reaction section are shown in Table 3.

[0057] Table 3 Operating conditions for each reaction stage in Example 1

[0058] Top reaction section Middle reaction section Bottom reaction section Temperature / °C 90 95 100 Pressure / MPa 0.08 0.1 0.12 <![CDATA[Illumination intensity / (kW / m 3 )]]> 2 2 2 Reaction time / h 1.3 1.3 1.3

[0059] Example 2:

[0060] A three-layer spray-type high-efficiency production device for chlorinated paraffin, the specific process is as follows: Figure 2 As shown.

[0061] The spray tower has a tail gas outlet (6) at the top, and a demister (5) is located below the tail gas outlet. Below the demister (5), there are three spray reaction sections from top to bottom. The upper part of each reaction section is equipped with a wax oil spraying device (7, 10, 13) to ensure uniform spraying of chlorinated paraffin oil, a gas distributor (9, 12, 15) to ensure uniform gas distribution, and a light source (8, 11, 14) for catalysis. The lower part of each reaction section is equipped with an internal heat exchanger (3, 17, 22) and a liquid storage device (4, 16, 23). The reaction sections are connected by gas-phase and liquid-phase external circulation pipelines.

[0062] The gas distributors (9, 12, 15) at the top of the reaction section are located below the wax oil spraying devices (7, 10, 13). The wax oil spraying devices (7, 10, 13) spray downwards with a chain length of C. 10 -C 20 The chlorinated paraffin oil has gas distributors (9, 12, 15) with downward-facing openings. The liquid injection direction is the same as the gas injection direction, while the liquid flow direction is opposite to the gas flow direction. The light sources (8, 11, 14) at the top of the reaction section are strip light sources between the wax oil spraying devices (7, 10, 13) and the gas distributors (9, 12, 15) inside the tower. Light sources (8, 14) are ultraviolet light sources, and light source (11) is a conventional light source. The light sources are fixed on the inner wall of the reaction section, illuminating the area between the wax oil spraying devices (7, 10, 13) and the gas distributors (9, 12, 15) in the reaction section.

[0063] The internal heat exchangers (3, 17, 22) at the bottom of the reaction section are immersed in the liquid stored in the liquid storage device (4, 16, 23). The internal heat exchangers (3, 17, 22) are coil-type heat exchangers, with circulating water flowing inside the coils and enamel coating on the outside of the coils.

[0064] The ratio of paraffin oil mass flow rate to chlorine mass flow rate in the spray tower is 1:4. The reflux ratio of each reactor section is 30, the residence time is 0.8 hours, and the light intensity and reaction pressure are the same. The reaction temperature differs from the chlorination depth of the material at the outlet of the liquid storage device. In the first reaction section, the light intensity is 1 kW / m². 3The reaction temperature was 90℃, the reaction pressure was 0.08MPa, and the chlorination depth of the material at the outlet of the liquid storage device (4) was 5%. The second reaction section had a light intensity of 1kW / m². 3 The reaction temperature is 100℃, the reaction pressure is 0.08MPa, and the chlorination depth of the material at the outlet of the liquid storage device (16) is 30%. In the third reaction section, the light intensity is 1kW / m3, the reaction temperature is 110℃, the reaction pressure is 0.08MPa, and the chlorination depth of the material at the outlet of the liquid storage device (23) is 52%. The height-to-diameter ratio of the reaction space between the spray device (7) at the top of the reaction section and the gas distributor (9) at the bottom of the reaction section is set to 1.5:1.

[0065] The liquid phase between adjacent reaction sections is connected by an external liquid phase circulation pipeline, and the pipeline is equipped with an external heat preservation device.

[0066] a. The chlorinated paraffin oil in the first reaction section is drawn from the bottom of the liquid storage device (4), and after heat exchange by the external heat exchanger (2), it enters the wax oil transfer pump (1). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (102) is mixed with fresh paraffin oil (103) and returns to the spray device (7) of the first reaction section. The other stream of chlorinated paraffin oil (101) enters the spray device (10) of the second reaction section.

[0067] b. The chlorinated paraffin oil in the second reaction section is drawn from the bottom of the liquid storage device (23), and after heat exchange by the external heat exchanger (20), it enters the wax oil transfer pump (21). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (113) is mixed with the chlorinated paraffin oil (101) from the first reaction section and returns to the spray device (7) of the second reaction section. The other stream of chlorinated paraffin oil (112) enters the spray device (13) of the third reaction section.

[0068] c. The chlorinated paraffin oil in the third reaction section is drawn from the bottom of the liquid storage device (16), heats it through the external heat exchanger (18), and then enters the transfer pump (19). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (111) is mixed with the chlorinated paraffin oil (112) from the second reaction section and returns to the spray device (13) of the third reaction section. The other stream of chlorinated paraffin oil (110) flows out of the device.

[0069] The gas phase between adjacent reaction sections is connected by an external gas phase circulation pipeline, which is insulated. Fresh chlorine gas (109) is introduced from the bottom of the third reaction section. The tail gas after the reaction is extracted from the top of the reaction section and connected to the gas distributor (12) of the second reaction section through a pipeline. The connecting pipeline does not extract the tail gas (108) and replenishes a certain amount of chlorine gas (107). The tail gas of the second reaction section is extracted from the top of the second reaction section and connected to the gas distributor (9) of the first reaction section through a pipeline. The connecting pipeline does not extract the tail gas (106) and does not replenish chlorine gas (105). The tail gas of the first reaction section is treated by removing the entrained wax oil through the demister (5) and then exits through the tail gas outlet (6) into the tail gas treatment system.

[0070] The quality of chlorinated paraffin oil (110) and chlorinated paraffin oil (111) both met the requirements of GB / T 40263-2021 for the determination of short-chain chlorinated paraffins.

[0071] The composition of the flow rate of each stream is shown in Table 4.

[0072] Table 4. Flow rates and chlorination depths of each liquid phase stream in Example 2.

[0073] Flowing Stock Mass flow rate (kg / h) Chlorination depth / % Fresh paraffin oil (103) 1250 0 Chlorinated paraffin oil (101) 1316 5 Chlorinated paraffin oil (102) 39480 5 Chlorinated paraffin oil (112) 1786 30 Chlorinated paraffin oil (113) 53580 30 Chlorinated paraffin oil (110) 2604 52 Chlorinated paraffin oil (111) 78120 52

[0074] The flow rate composition of each gas phase stream is shown in Table 5.

[0075] Table 5. Gas phase inlet and outlet flow rates and composition in Example 2

[0076]

[0077] The operating conditions for each reaction section are shown in Table 6.

[0078] Table 6 Operating conditions for each reaction stage in Example 2

[0079] Top reaction section Middle reaction section Bottom reaction section Temperature / °C 90 100 110 Pressure / MPa 0.08 0.08 0.08 <![CDATA[Illuminance intensity / (kW / m 3 )]]> 1 1 1 Reaction time / h 0.8 0.8 0.8

[0080] Example 3:

[0081] A three-layer spray-type high-efficiency production device for chlorinated paraffin, the specific process is as follows: Figure 3 As shown.

[0082] The spray tower has a tail gas outlet (6) at the top, and a demister (5) is located below the tail gas outlet. Below the demister (5), there are three spray reaction sections from top to bottom. The upper part of each reaction section is equipped with a wax oil spraying device (7, 10, 13) to ensure uniform spraying of chlorinated paraffin oil, a gas distributor (9, 12, 15) to ensure uniform gas distribution, and a light source (8, 11, 14) for catalysis. The lower part of each reaction section is equipped with an internal heat exchanger (3, 17, 22) and a liquid storage device (4, 16, 23). The reaction sections are connected by gas-phase and liquid-phase external circulation pipelines.

[0083] The gas distributors (9, 12, 15) at the top of the reaction section are located below the wax oil spraying devices (7, 10, 13). The wax oil spraying devices (7, 10, 13) spray downwards evenly with a chain length of C. 10 -C 20 The chlorinated paraffin oil has gas distributors (9, 12, 15) with downward-facing openings. The liquid spray direction is the same as the gas spray direction, and the liquid flow direction is opposite to the gas flow direction. The light sources (8, 11, 14) at the top of the reaction section are located between the wax oil spraying devices (7, 10, 13) and the gas distributors (9, 12, 15) inside the tower. Light sources (8, 14) are scattered ultraviolet light sources, and light source (11) is a common strip light source. Light source (11) is fixed on the inner wall of the reaction section, and light sources (8, 14) are fixed on the outside of the tower's viewing window openings, both illuminating the area between the wax oil spraying devices (7, 10, 13) and the gas distributors (9, 12, 15) in the reaction section.

[0084] The internal heat exchangers (3, 17, 22) at the bottom of the reaction section are immersed in the liquid stored in the liquid storage device (4, 16, 23). The internal heat exchangers (3, 17, 22) are coil-type heat exchangers, with circulating water flowing inside the coils and enamel coating on the outside of the coils.

[0085] The ratio of paraffin oil mass flow rate to chlorine mass flow rate in the spray tower is 1:5. The reflux ratio of each reactor section is 20, the residence time is 0.4 hours, and the reaction pressure is the same. However, the light intensity, reaction temperature, and chlorination depth of the material at the outlet of the liquid storage device differ. In the first reaction section, the light intensity is 5 kW / m². 3 The reaction temperature was 70℃, the reaction pressure was 0.12MPa, and the chlorination depth of the material at the outlet of the liquid storage device (4) was 5%. The second reaction section had a light intensity of 2kW / m². 3 The reaction temperature was 90℃, the reaction pressure was 0.12MPa, and the chlorination depth of the material at the outlet of the liquid storage device (16) was 35%. The third reaction section had a light intensity of 5kW / m². 3The reaction temperature is 100℃, the reaction pressure is 0.12MPa, and the chlorination depth of the material at the outlet of the liquid storage device (23) is 52%. The height-to-diameter ratio of the reaction space between the spray device (7) at the top of the reaction section and the gas distributor (9) at the bottom of the reaction section is set to 3:1.

[0086] The liquid phase between adjacent reaction sections is connected by an external liquid phase circulation pipeline, and the pipeline is equipped with an external heat preservation device.

[0087] a. The chlorinated paraffin oil in the first reaction section is drawn from the bottom of the liquid storage device (4), and after heat exchange by the external heat exchanger (2), it enters the wax oil transfer pump (1). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (102) is mixed with fresh paraffin oil (103) and returns to the spray device (7) of the first reaction section. The other stream of chlorinated paraffin oil (101) enters the spray device (10) of the second reaction section.

[0088] b. The chlorinated paraffin oil in the second reaction section is drawn from the bottom of the liquid storage device (23), and after heat exchange by the external heat exchanger (20), it enters the wax oil transfer pump (21). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (113) is mixed with the chlorinated paraffin oil (101) from the first reaction section and returns to the spray device (7) of the second reaction section. The other stream of chlorinated paraffin oil (112) enters the spray device (13) of the third reaction section.

[0089] c. The chlorinated paraffin oil in the third reaction section is drawn from the bottom of the liquid storage device (16), and after heat exchange by the external heat exchanger (18), it enters the transfer pump (19), and after being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (111) is mixed with the chlorinated paraffin oil (112) from the second reaction section and returns to the spray device (13) of the third reaction section. The other stream of chlorinated paraffin oil (110) exits the device.

[0090] The gas phase between adjacent reaction sections is connected by an external gas phase circulation pipeline, which is insulated. Fresh chlorine gas (109) is introduced from the bottom of the third reaction section. The tail gas after the reaction is partially extracted from the top of the reaction section and mixed with a certain amount of chlorine gas (107). It is then connected to the gas distributor (12) of the second reaction section through a pipeline, and part of it is connected to the gas distributor (9) of the first reaction section through the reaction tail gas pipeline and the tail gas pipeline. The tail gas of the second reaction section is extracted from the top of the second reaction section and connected to the gas distributor (9) of the first reaction section through a pipeline. No chlorine gas (105) is added. The tail gas of the first reaction section is treated by removing the entrained wax oil through the demister (5) and then exits through the tail gas outlet (6) into the tail gas treatment system.

[0091] The composition of the flow rate of each stream is shown in Table 7.

[0092] Table 7. Flow rates and chlorination depths of each liquid phase stream in Example 3.

[0093] Flowing Stock Mass flow rate (kg / h) Chlorination depth / % Fresh paraffin oil (103) 1250 0 Chlorinated paraffin oil (101) 1316 5 Chlorinated paraffin oil (102) 26320 5 Chlorinated paraffin oil (112) 1923 35 Chlorinated paraffin oil (113) 38460 35 Chlorinated paraffin oil (110) 2604 52 Chlorinated paraffin oil (111) 52080 52

[0094] The flow rate composition of each gas phase stream is shown in Table 8.

[0095] Table 8. Gas phase inlet and outlet flow rates and composition in Example 3

[0096]

[0097] The operating conditions for each reaction section are shown in Table 9.

[0098] Table 9. Operating conditions for each reaction stage in Example 3

[0099] Top reaction section Middle reaction section Bottom reaction section Temperature / °C 70 90 100 Pressure / MPa 0.12 0.12 0.12 <![CDATA[Illumination intensity / (kW / m 3 )]]> 5 2 5 Reaction time / h 0.4 0.4 0.4 .

Claims

1. A spray-type multi-stage tower-type continuous production apparatus for chlorinated paraffin, characterized in that, The system includes a spray tower body, with a tail gas outlet and a demister at the top. Several reaction sections are located below the tail gas outlet, with a demister at the top of the uppermost reaction section. Each reaction section has a spray device for uniform liquid spraying, a light source for catalysis, and a gas distributor for uniform gas distribution at the bottom. Each reaction section has a heat exchange device and a liquid storage device at the bottom. The reaction sections are connected to each other via external gas-phase circulation pipelines and external liquid-phase circulation pipelines. The liquid-phase external circulation pipeline between each reaction section is led out from the liquid storage device, and after passing through the external heat exchanger and the transfer pump, it is divided into two streams. One stream returns to the spray device of this section, and the other stream enters the spray device of the next section. The gas-phase external circulation pipeline between each reaction section is led out from the top of the next reaction section and connected to the gas distributor of the current reaction section. The pipeline is equipped with gas inlet and outlet branch pipelines in the middle.

2. The apparatus for continuous production of chlorinated paraffin using a multi-stage spray tower as described in claim 1, characterized in that, The liquid injection direction of the spray device is the same as the gas injection direction of the gas distributor, and the liquid flow direction in the reaction section is opposite to the gas flow direction.

3. The apparatus for continuous production of chlorinated paraffin using a multi-stage spray tower as described in claim 1, characterized in that, The light sources at the top of each reaction section are evenly distributed between the spray device and the gas distribution device; the illuminance of the light sources is 1-5 kW / m². 3 .

4. The apparatus for continuous production of chlorinated paraffin using a multi-stage spray tower as described in claim 3, characterized in that, The heat exchange devices at the bottom of each reaction section are immersed in the liquid stored in the liquid storage device.

5. A method for continuous production of chlorinated paraffin using a multi-stage spray tower, based on the apparatus for continuous production of chlorinated paraffin using a multi-stage spray tower as described in any one of claims 1-4, wherein the space between the spray device (7) at the top of the reaction section and the gas distributor (9) at the bottom of the reaction section is designated as a reaction space, and the reaction rate and depth are controlled by adjusting the height-to-diameter ratio of the reaction space to 0.1:1 to 4:

1. The production method includes the following processes: The paraffin sprayed downward by the spray device (7) at the top of the reaction section reacts with the chlorine gas sprayed by the gas distributor (9) at the bottom of the reaction section. After the reaction, the liquid enters the liquid storage device (4) and is temperature controlled by the internal heat exchanger (3) in the liquid storage device. The chlorinated paraffin oil in the reaction section is drawn from the bottom of the liquid storage device, and after heat exchange by the external heat exchanger (2), it enters the paraffin oil transfer pump (1). After being pressurized, it is divided into two streams. One stream of chlorinated paraffin oil (102) is mixed with fresh paraffin oil (103) and returned to the spray device (7) of this stage reaction section. The other stream of chlorinated paraffin oil (101) enters the spray device of the next stage reaction section. Each reaction section of the spray tower is equipped with a light source inside or outside for photocatalytic reaction.

6. The method for continuous production of chlorinated paraffin using a multi-stage spray tower according to claim 5, characterized in that, The fresh paraffin oil is C. 10 -C 30 The liquid paraffin; the temperature of each reaction section in the spray tower is controlled at 70-110℃; the pressure in the spray tower is controlled at 0.08-0.12 MPa.

7. The method for continuous production of chlorinated paraffin using a multi-stage spray tower according to claim 6, characterized in that, The ratio of the mass flow rate of paraffin oil to the mass flow rate of chlorine gas in the spray tower is 1:1-6; the reflux ratio of each reaction section of the spray tower is 20-60; and the chlorine content of the material in each reaction section of the spray tower is maintained at a gradient of 5-30%.

8. The method for continuous production of chlorinated paraffin using a multi-stage spray tower according to claim 5, characterized in that, Each reaction section inside or outside the spray tower is equipped with a light source, which is a common light source or an ultraviolet light source; the light source is a scattered light source or a strip light source.

9. The method for continuous production of chlorinated paraffin using a multi-stage spray tower according to claim 5, characterized in that, The height-to-diameter ratio of the reaction space between the spray device (7) at the top of the reaction section and the gas distributor (9) at the bottom of the reaction section is set to 0.1:1 to 4:1; the residence time of the material in the spray tower is 0.1-3 hours.

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