Efficient separation process for polyethylene wax

Abstract

The invention relates to an efficient separation process of polyethylene wax, which comprises the following steps: melting and pressurizing polyethylene wax, feeding the molten and pressurized polyethylene wax into a flash evaporation device in a spray form for flash evaporation separation, and heating to completely melt the polyethylene wax. Compared with the prior art, the efficient polyethylene wax separation process provided by the invention has the advantages that the polyethylene wax can be efficiently refined and separated, various high-purity polyethylene wax products can be obtained, and the defects that the existing polyethylene wax separation process is low in efficiency, various high-purity and high-value products are difficult to obtain, the process steps are complicated and the like are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of polyethylene wax refining, and in particular to a polyethylene wax efficient separation process. Background Art

[0002] Polyethylene wax is an important chemical raw material and fine chemical with a wide range of uses and high demand. In a narrow sense, polyethylene wax is a homopolymer of polyethylene (PE) with a low molecular weight, usually between 1000 and 8000, and a density of 0.920 to 0.936 g / cm 3 , most of them are white or light yellow, in powder, flake or block form. The preparation methods of polyethylene wax are divided into ethylene polymerization method, polyethylene thermal cracking method and high-density polyethylene (HDPE) device by-product method. With the increase in HDPE production capacity, the output of by-product polyethylene wax has increased year by year, and its use value has become increasingly prominent, but the by-product polyethylene wax has the following disadvantages: (1) The purity is not high and the molecular weight distribution is wide, which cannot meet the requirements of high heat resistance and high fluidity applications; (2) It contains more light components and residual solvents, which will evaporate and produce a large amount of thick smoke during the processing, which cannot meet environmental protection requirements and has a limited scope of application; (3) It has a wide melting range and is usually a mixture of several oligomers with different polymerization degrees, and its stability is difficult to control. Therefore, the by-product polyethylene wax needs to be refined before it can be further used.

[0003] At present, the refining methods of by-product wax include pressurized flash distillation, vacuum distillation, solvent crystallization and steam distillation. For example, patent CN 108148151 A discloses a refining method and a refining device for polyethylene wax crude product, which uses steam to strip polyethylene wax crude product to obtain separated primary stripped polyethylene wax and steam mixed with light components, and then dehydrates the primary stripped polyethylene wax to obtain refined polyethylene wax. Patent CN 109897124 B discloses a continuous preparation device and a preparation method for refined polyethylene wax, which uses solid polyethylene wax crude product as raw material, and uses superheated steam to melt and strip solid polyethylene wax crude product under normal pressure to prepare refined polyethylene wax. Patent CN 212741198 U discloses a new type of crude polyethylene wax refining device, which uses a vacuum stripping process to remove light oil and water in crude polyethylene wax at the same time, does not require the introduction of water vapor, does not produce wastewater, reduces energy consumption, and reduces pollution. Patent CN 117964800 A discloses a process for purifying by-product polyethylene wax, which uses high-temperature steam in a crude wax flash tank to deactivate residual catalysts, uses steam and nitrogen in a crude wax purification tank to remove hexane and heavy hydrocarbons, and removes light oil components in refined wax under high temperature and negative pressure conditions from the purified wax, thereby performing a secondary separation of hexane and light oil components.

[0004] The polyethylene wax refining processes disclosed in the prior art mostly adopt steam distillation or vacuum stripping processes, the separation and purification efficiency of polyethylene wax is not high, and a dehydration step is required, which increases the complexity of the system. Therefore, how to develop an efficient polyethylene wax refining and separation process is still a technical problem that needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a polyethylene wax efficient separation process in order to solve the above problems.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] The invention discloses a polyethylene wax efficient separation process, wherein the polyethylene wax is melted and pressurized, and the melted and pressurized polyethylene wax is sprayed into a flash evaporation device for flash evaporation separation.

[0008] As a preferred technical solution of the present invention, the polyethylene wax is completely melted after heating, the heating temperature is higher than the melting point of the polyethylene wax, the heating melting temperature is 5 to 70°C higher than the melting point of the polyethylene wax, preferably 10 to 50°C, for example, the polyethylene wax melting point is usually 80-130°C, the polyethylene wax melting temperature is 90 to 200°C, preferably, the polyethylene wax melting temperature is 120 to 180°C, and more preferably, the polyethylene wax melting temperature is 130 to 170°C.

[0009] As a preferred technical solution of the present invention, the polyethylene wax is pressurized by a booster pump or an inert gas.

[0010] As a preferred technical solution of the present invention, the flash evaporation device includes a flash tank. Preferably, the flash tank is a negative pressure flash tank.

[0011] As a preferred technical solution of the present invention, the flash evaporation device is connected to a spray mechanism for forming a spray film from the molten polyethylene wax.

[0012] As a preferred technical solution of the present invention, the spraying mechanism includes an atomizing nozzle or a spray head.

[0013] As a preferred technical solution of the present invention, the spraying mechanism is a rotary atomizing nozzle.

[0014] As a preferred technical solution of the present invention, the light component separated by flash evaporation is discharged from the top of the flash evaporation device and condensed by a condensation unit;

[0015] The heavy components separated by flash evaporation are discharged from the bottom of the flash evaporation device and collected by a collecting device.

[0016] As a preferred technical solution of the present invention, the condensation unit is a multi-stage condensation unit, which is composed of multiple groups of condensers with different temperatures connected in series, and the condenser temperature is gradually reduced to obtain a variety of light component products;

[0017] And / or, the heavy component obtained by the collecting device is subjected to spray flash separation again or multiple times to obtain a high-purity polyethylene wax product.

[0018] As a preferred technical solution of the present invention, the polyethylene wax efficient separation process comprises the following steps:

[0019] The molten pressurized polyethylene wax is formed into a spray film by at least one set of jet flash evaporation units for flash evaporation separation;

[0020] Buffering and supplying molten polyethylene wax through at least one group of melt buffer units, wherein the melt buffer units are connected to the inlet of the jet flash unit through pipelines;

[0021] The light component gas phase material obtained by flash separation is condensed by at least one set of condensation separation units, and the condensation separation units are connected to the top outlet of the jet flash unit through pipelines.

[0022] As a preferred technical solution of the present invention, the jet flash evaporation units are provided in multiple groups, which are connected in parallel and / or in series to form a high-efficiency separation system.

[0023] As a preferred technical solution of the present invention, the jet flash evaporation units are provided with 2 to 6 groups, preferably 3 to 4 groups, which are connected in series.

[0024] As a preferred technical solution of the present invention, the molten buffer unit is arranged between two adjacent jet flash units;

[0025] As a preferred technical solution of the present invention, along the material flow direction, the temperature of the jet flash unit increases step by step, and the temperature difference between adjacent melting buffer units is 2 to 10°C, preferably 3 to 5°C;

[0026] As a preferred technical solution of the present invention, the temperature of the molten cache unit is the same as the temperature of the jet flash unit connected downstream thereof.

[0027] As a preferred technical solution of the present invention, a booster delivery pump is provided between the molten buffer unit and the jet flash unit;

[0028] As a preferred technical solution of the present invention, the jet flash unit comprises a jet flash tank with temperature control;

[0029] As a preferred technical solution of the present invention, the molten cache unit includes a molten cache tank with temperature control.

[0030] As a preferred technical solution of the present invention, the jet flash tank and the molten buffer tank are provided with heat exchange jackets, and heating is controlled by introducing a heat exchange medium (such as superheated steam or heat transfer oil).

[0031] As a preferred technical solution of the present invention, the separation and refining system also includes a raw material tank, the outlet of which is connected to the inlet of the molten buffer unit through a pipeline, and the raw material tank is used to store the initial polyethylene wax raw material to be processed.

[0032] As a preferred technical solution of the present invention, the condensation separation unit includes 1 to 5 stages of condensation tanks, preferably 2 to 4 stages of condensation tank groups, multiple condensation tanks are connected in series in sequence, the condensation temperature decreases step by step, and the temperature difference between adjacent condensation tanks is 2 to 10° C., preferably 3 to 5° C. By setting multiple groups of condensation tank groups with gradually decreasing condensation temperatures, light components with different boiling points can be obtained, so that light components in a wide distillation range can be cut step by step to obtain finer products of different grades, which is helpful to obtain products with higher application value.

[0033] As a preferred technical solution of the present invention, the condensation tank is connected to a vacuum pump, and a vacuum condensation tank is formed by vacuuming the tank with the vacuum pump, and the end of the condensation separation unit is connected to an exhaust gas treatment device.

[0034] Preferably, the tail gas treatment equipment includes a tail gas absorption tank (filled with kerosene or diesel), an RTO or ATM treatment unit, which is used to treat the non-condensable gas to avoid environmental pollution.

[0035] Compared with the prior art, the present invention has the following innovative features:

[0036] The present invention forms a liquid phase particle film from the molten polyethylene wax through a spray mechanism, and quickly flashes in the form of a spray film. This spray film separation method forms a high specific surface area film structure, improves mass transfer efficiency, accelerates evaporation speed, reduces energy consumption, is easy to control and operate, has great advantages in the polyethylene wax refining process, and greatly improves production efficiency and product quality. Its specific principle is that after the molten polyethylene wax forms a mist film, the same mass of polyethylene wax exposes a larger specific surface area. During the flash evaporation process, the contact area of ​​the polyethylene wax film increases, which promotes the mass transfer process. The polyethylene wax can evaporate quickly, which helps to quickly separate the light and heavy components during the flash evaporation process; at the same time, since the spray film separation method can achieve an efficient mass transfer process at a relatively low temperature, its energy consumption is low, no water vapor needs to be introduced, and the dehydration step is reduced, which helps to reduce production costs. In addition, the operation of the spray film separation method is relatively simple, and the control requirements for operating parameters are relatively low. Only by adjusting the conditions for the formation of the spray film and the temperature, pressure and other parameters during the flash evaporation process, the separation process can be accurately controlled.

[0037] The present invention can achieve fine cutting and separation of polyethylene wax through the series and / or parallel combination of jet flash units and a multi-stage condensation tank group, and can obtain up to a dozen different ranges of high-purity, high-value-added polyethylene wax and polyethylene oil products. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of a polyethylene wax multi-stage separation and purification system shown in Example 1 of the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the rotary atomizing nozzle used in Example 2 of the present invention;

[0040] Figure 3 for Figure 2 Explosion diagram of

[0041] Figure 4 It is a schematic diagram of the main view of a small test bench shown in Example 3 of the present invention;

[0042] Figure 5 The following are the actual photos of the light and heavy components obtained in Experiment 3 of Example 3;

[0043] Reference numerals:

[0044] 100-Raw material tank;

[0045] 201-first melting cache tank; 202-second melting cache tank; 203-third melting cache tank;

[0046] 301-first jet flash tank; 302-second jet flash tank; 303-third jet flash tank;

[0047] 400-injection mechanism; 401-outer sleeve; 402-rotating connecting pipe; 403-multi-hole nozzle; 4031-opening; 404-ball bearing assembly; 405-internal thread connector;

[0048] 500 - condensation separation unit; 501 - first condensation tank; 502 - second condensation tank; 503 - third condensation tank; 504 - tail gas absorption tank. DETAILED DESCRIPTION

[0049] The present invention is described in detail below. All matters not described in detail in the present invention are technical solutions already disclosed in the art.

[0050] In order to solve the defects of the current polyethylene wax separation and refining process, such as low purification efficiency, difficulty in obtaining a variety of high-value products, and the need for an additional dehydration step, the present invention provides a polyethylene wax efficient separation process, which can efficiently and concisely obtain a variety of high-value products.

[0051] Example 1

[0052] A highly efficient separation process for polyethylene wax Figure 1The polyethylene wax multi-stage separation and refining system shown is used for separation. The system is equipped with 3 groups of jet flash units, 3 groups of melt buffer units and 3 groups of condensation separation units. The melt buffer units and the jet flash units are connected in series in sequence. The condensation separation unit is arranged at the top outlet of the jet flash unit to condense the light component gas phase material obtained by flash separation.

[0053] Specifically, see Figure 1 The separation and refining system is provided with a raw material tank 100, which is used to store the polyethylene wax raw material to be processed. The outlet of the raw material tank 100 is connected to the inlet of the first melting buffer tank 201 through a pipeline, the outlet of the first melting buffer tank 201 is connected to the inlet of the first jet flash tank 301 through a pipeline, the bottom discharge port of the first jet flash tank 301 is connected to the inlet of the second melting buffer tank 202, the outlet of the second melting buffer tank 202 is connected to the inlet of the second jet flash tank 302 through a pipeline, the bottom discharge port of the second jet flash tank 302 is connected to the inlet of the third melting buffer tank 203, and the outlet of the third melting buffer tank 203 is connected to the inlet of the third jet flash tank 303 through a pipeline. A control valve and a booster delivery pump are provided in the pipeline between the adjacent melting buffer tanks and the jet flash tanks, and the flow rate and pressure of the molten polyethylene wax can be controlled by setting the parameters of the booster delivery pump. The melting buffer tank is used to cache the heavy component material after flashing of the upstream jet flash tank and reserve raw materials for the next-level jet flash tank. Both the jet flash tank and the melt buffer tank are provided with heat exchange jackets, and the temperature is controlled by passing superheated steam for heating. Along the material flow direction, the temperature of the jet flash tank increases step by step, and the temperature difference between adjacent melt buffer tanks is about 10°C. The temperature of the melt buffer tank is the same as the temperature of the jet flash tank connected downstream. In this embodiment, the temperatures of the first jet flash tank 301, the second jet flash tank 302, and the third jet flash tank 303 are controlled to be approximately 135°C, 145°C, and 155°C, respectively. By setting the jet flash tanks with gradually increasing temperatures, the components in the polyethylene wax can be separated step by step, and more products with high application value can be cut out.

[0054] See also Figure 1The top outlets of the first jet flash tank 301, the second jet flash tank 302, and the third jet flash tank 303 are all connected to the condensation separation unit 500, and the condensation separation unit 500 includes the first condensation tank 501, the second condensation tank 502, the third condensation tank 503, the vacuum pump, and the tail gas absorption tank 504 connected in sequence. Multiple condensation tanks are connected in series in sequence, and the condensation temperature decreases step by step. The temperature difference between adjacent condensation tanks is about 5°C. By setting multiple groups of condensation tanks with gradually decreasing condensation temperatures, light components with different boiling points can be obtained, and light components with a wide distillation range can be cut step by step to obtain more refined different high-grade products. The condensation tank is connected to a vacuum pump, and a vacuum condensation tank is formed by vacuuming the vacuum pump to achieve more efficient component separation. The end of the condensation separation unit is connected to the tail gas treatment equipment, and the tail gas treatment equipment includes a tail gas absorption tank (filled with kerosene or diesel inside), an RTO or ATM treatment unit to treat the non-condensable tail gas.

[0055] In this system, the material inlet of the first jet flash tank 301, the second jet flash tank 302, and the third jet flash tank 303 is equipped with a spray mechanism for forming a spray film of the molten pressurized polyethylene wax. As a specific preferred embodiment, the spray mechanism in this embodiment adopts an atomizing nozzle or a nozzle, and the aperture of the atomizing nozzle or the nozzle is selected according to the actual situation. For example, an atomizing nozzle or a nozzle with an aperture of 1 to 10 mm is used, and a solid cone spray is preferably used to generate a circular impact area. More preferably, the flash tank preferably adopts a vacuum flash tank.

[0056] In this system, the melted and pressurized polyethylene wax is formed into a liquid phase particle film through the injection mechanism, and enters the flash tank in the form of a spray film for flash evaporation, which is the key to achieving efficient separation of light and heavy components. The molten and pressurized polyethylene wax is formed into a liquid phase particle film, and the same mass of polyethylene wax is exposed to a larger specific surface area. During the flash evaporation process, the contact area of ​​the polyethylene wax film increases, which promotes the heat and mass transfer process, making the distillation and separation more efficient and thorough, and helping to quickly achieve the separation of light and heavy components during the flash evaporation process. In addition, since the spray membrane separation method can achieve an efficient mass transfer process at a relatively low temperature, it has low energy consumption, does not require the introduction of water vapor, and reduces the step of water removal, which helps to simplify the system structure and reduce production costs.

[0057] Example 2

[0058] Compared with Example 1, the spray mechanism specifically adopts a rotary atomizing nozzle, which helps to further increase the atomization efficiency, improve the atomization uniformity, enhance the liquid dispersibility and reduce the particle size, and can effectively improve the spray separation effect.

[0059] Reference Figure 2 , Figure 3The rotary atomizing nozzle specifically includes an outer sleeve 401, a rotary connecting pipe 402 and at least one porous nozzle 403. The rotary connecting pipe 402 is rotatably connected to the outer sleeve 401 along the axial direction. The porous nozzle 403 is fixedly installed on the side wall of the rotary connecting pipe 402 along the radial direction. A row of openings 4031 is arranged on the porous nozzle 403. The arrangement direction of the openings 4031 is inclined at an angle of about 5° with the axial direction of the porous nozzle 403. There are two porous nozzles 403, which are symmetrically arranged in pairs on the rotary connecting pipe 402. The rotary connecting pipe 402 is rotatably connected to the outer sleeve 401 through a ball bearing assembly 404 arranged in the outer sleeve 401, wherein the ball bearing assembly 404 includes a ball, a limit bolt, etc. An internal thread connector 405 is installed in the outer sleeve 401 to facilitate the installation and connection of the rotary atomizing nozzle.

[0060] The rotary atomizing nozzle is installed on the jet flash tank. When the high-speed and high-pressure molten polyethylene wax is sprayed through the multiple openings 4031 of the porous nozzle 403, the pressure can be used to automatically start the rotation mode through the openings 4031 of the structure, so that the porous nozzle 403 rotates together with the rotating connecting pipe 402 to form a large-scale spray film, expand the mist film area, and the rotary atomizing nozzle forms a uniform film around the liquid around the nozzle, which is conducive to uniform atomization of the liquid, thereby improving the atomization effect and separation effect. The rotary atomizing nozzle also generates a rotary flow to increase the shear force of the liquid, which helps to disperse the liquid into smaller particles. In addition, the rotary atomizing nozzle causes the droplets to continuously collide and split during the rotation process, increasing the collision frequency of the particles, which is conducive to forming smaller particles and improving the spray separation effect.

[0061] Example 3

[0062] Figure 4 It is a small test bench device shown in the present invention. The equipment includes a feed tank 1 and a flash tank 2. The feed tank 1 and the flash tank 2 are both installed in an insulated box that can accurately control the temperature. The temperature of the feed tank 1 and the flash tank 2 is controlled by heating the insulated box. The feed tank 1 and the flash tank 2 are connected by a pipeline. The feed port of the flash tank 2 is equipped with a nozzle with a diameter of about 2 mm. The polyethylene wax that is completely melted in the feed tank 1 enters the flash tank 2 in the form of a spray film under pressure to achieve rapid flash separation. The top of the flash tank 2 is connected to the condenser 3 through a pipeline. The condenser 3 is located outside the insulated box. The condenser 3 is provided with a jacket and cooling water is passed inside. The condenser 3 is connected to the vacuum pump, and the vacuum pump is turned on to evacuate during the experiment. The separated light components are condensed and collected by the condenser 3, and the light components are obtained by discharging from the bottom of the condenser 3. A discharge port is provided at the bottom of the flash tank 2, and the heavy component substances are discharged after the experiment.

[0063] During the specific experiment, the operation steps include: (1) connecting the experimental device to the high-pressure nitrogen inlet pipe. After the experiment starts, nitrogen is used for multiple gas replacement to remove the air in the device; (2) adding polyethylene wax crude product to the feeding tank 1, removing the air in the raw material by gas replacement, then closing all valves, setting the heating temperature of the insulation box (120-180°C), and maintaining the temperature for more than 1 hour after it reaches the set value to ensure that the polyethylene wax crude product is completely melted; (3) opening the nitrogen inlet valve, injecting the molten polyethylene wax in the feeding tank 1 into the flash tank 2, and the molten polyethylene wax enters the flash tank 2 in the form of spray after passing through the nozzle for flash separation, and the separated light component enters the condensation tank 3, and the separated heavy component enters the bottom of the flash tank 2; (4) After collecting the light and heavy components, test the product performance.

[0064] The following experiments were carried out using this device:

[0065] 1. Weigh about 500g of polyethylene wax raw material (white spherical substance with a certain viscosity, molecular weight range of 30-5500), and conduct experiments at the temperature of the insulation box set at 125℃, 130℃, 140℃, 150℃, 160℃, and 180℃. The average value of the three groups of experimental results is calculated. The experimental results are detailed in Table 1. Figure 5 This is a photo of the light and heavy components obtained in Experiment 3. The light component is a light yellow oily substance, and the heavy component is a white solidified material. As shown in Table 1, different light and heavy component materials were obtained at different temperatures. The molecular weight of the obtained light component was measured, and light components with different molecular weight distribution ranges were obtained at different temperatures. The higher the temperature, the larger the molecular weight; at the same time, the higher the temperature, the higher the hardness of the obtained heavy component after solidification, indicating that the separation of light and heavy components can be achieved by this method, and the obtained polyethylene wax heavy component has high purity.

[0066] Table 1

[0067]

[0068] 2. Weigh about 750g of polyethylene wax raw material, conduct experiments at a set temperature of 130℃, collect light and heavy components at 130℃; add the heavy components obtained at 130℃ as raw materials to flash tank 2, conduct experiments at a set temperature of 150℃, collect light and heavy components; add the heavy components obtained at 150℃ as raw materials to flash tank 2, conduct experiments at a set temperature of 180℃, collect light and heavy components, test the performance of the product, and calculate according to the average value of the three groups of experimental results. The experimental results are shown in Table 2. It can be seen from Table 2 that through this method, light components with a certain range of molecular weight distribution can be obtained, and high-purity polyethylene oligomer products can be obtained (such as polyethylene oil with a molecular weight between 1167 and 1692 obtained in Experiment 8), which greatly improves the product value.

[0069] Table 2

[0070] Experiment 7 Experiment 8 Experiment 9 Set temperature / ℃ 130 150 180 Light component state Light yellow oil Light yellow oil Light yellow oil Light component molecular weight 39～1208 1167～1692 1604～2672 Recombinant status White solidified material White solidified material Light yellow solidified material

[0071] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A polyethylene wax efficient separation process, characterized in that: The polyethylene wax is melted and pressurized, and the melted and pressurized polyethylene wax is sprayed into a flash evaporation device for flash evaporation separation.

2. A polyethylene wax efficient separation process according to claim 1, characterized in that: The polyethylene wax is completely melted after heating, and the heating temperature is higher than the melting point of the polyethylene wax; And / or, the polyethylene wax is pressurized by a booster pump or an inert gas.

3. A polyethylene wax efficient separation process according to claim 1, characterized in that: The flash evaporation device comprises a flash tank. Preferably, the flash tank is a negative pressure flash tank.

4. A polyethylene wax efficient separation process according to claim 1, characterized in that: The flash evaporation device is connected to a spray mechanism for forming a spray film from the molten polyethylene wax.

5. A polyethylene wax efficient separation process according to claim 4, characterized in that: The spraying mechanism comprises an atomizing nozzle or a spray head.

6. A polyethylene wax efficient separation process according to claim 5, characterized in that: The spraying mechanism is a rotary atomizing nozzle.

7. A polyethylene wax efficient separation process according to claim 1, characterized in that: The light component separated by flash evaporation is discharged from the top of the flash evaporation device and condensed in a condensation unit; The heavy components separated by flash evaporation are discharged from the bottom of the flash evaporation device and collected by a collecting device.

8. A polyethylene wax efficient separation process according to claim 7, characterized in that: The condensation unit is a multi-stage condensation unit, which is composed of multiple groups of condensers with different temperatures connected in series, and the condenser temperature is gradually reduced to obtain a variety of light component products; And / or, the heavy component obtained by the collecting device is subjected to spray flash separation again or multiple times to obtain a high-purity polyethylene wax product.

9. A polyethylene wax efficient separation process according to claim 1, characterized in that: The following steps are involved: The molten pressurized polyethylene wax is formed into a spray film by at least one set of jet flash evaporation units for flash evaporation separation; Buffering and supplying molten polyethylene wax through at least one group of melt buffer units, wherein the melt buffer units are connected to the inlet of the jet flash unit through pipelines; The light component gas phase material obtained by flash separation is condensed by at least one set of condensation separation units, and the condensation separation units are connected to the top outlet of the jet flash unit through pipelines.

10. A polyethylene wax efficient separation process according to claim 9, characterized in that: The jet flash unit is provided with multiple groups, which are connected in parallel and / or in series to form a high-efficiency separation system.

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