Polyethylene wax multistage separating and refining system

Abstract

The invention relates to a polyethylene wax multi-stage separation refining system, which is provided with at least one group of spraying flash evaporation unit and at least one group of condensation separation unit, the spraying flash evaporation unit is used for enabling molten and pressurized polyethylene wax to form a spraying film for flash evaporation separation, and the condensation separation unit is connected with a top outlet of the spraying flash evaporation unit through a pipeline. And the condenser is used for condensing the light-component gas-phase material obtained by flash separation. Compared with the prior art, the separating and refining system provided by the invention has the advantages that the polyethylene wax can be efficiently refined and separated, various high-purity polyethylene wax or oil products can be obtained, and the defects that the existing polyethylene wax separating process is low in efficiency, various 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 multi-stage separation and refining system. 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] Most of the polyethylene wax refining processes disclosed in the prior art use steam distillation or vacuum stripping processes, and the separation and purification efficiency of polyethylene wax is not high. In addition, the existing processes only obtain a specific polyethylene wax product, and it is difficult to separate and obtain a variety of high-value polyethylene wax products. Therefore, how to develop an efficient polyethylene wax refining and separation process to obtain a variety of high-value polyethylene wax products 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 multi-stage separation and purification system in order to solve the above problems.

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

[0007] A polyethylene wax multi-stage separation and refining system, comprising:

[0008] At least one set of jet flash evaporation units, used for forming the molten pressurized polyethylene wax into a spray film for flash evaporation separation;

[0009] At least one set of condensation separation units is connected to the top outlet of the jet flash unit through a pipeline and is used to condense the light component gas phase material obtained by flash separation.

[0010] 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.

[0011] 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.

[0012] As a preferred technical solution of the present invention, it also includes at least one group of melt buffer units, which are connected to the inlet of the jet flash unit through a pipeline and are used for buffering and supplying molten polyethylene wax;

[0013] The melt buffer unit is arranged between two adjacent jet flash units, and is used to buffer the heavy component material after flash evaporation in the upstream jet flash unit;

[0014] 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;

[0015] The temperature of the melt buffer unit is the same as the temperature of the jet flash unit connected downstream thereof.

[0016] By setting up multiple groups of jet flash evaporation units with gradually increasing temperatures, the components in the polyethylene wax can be separated step by step, cutting out products with higher application value.

[0017] As a preferred technical solution of the present invention, a booster delivery pump is provided between the molten buffer unit and the jet flash evaporation unit, and the flow rate and pressure of the molten polyethylene wax can be controlled by setting the parameters of the booster delivery pump.

[0018] and / or, the jet flash unit comprises a jet flash tank with temperature control;

[0019] And / or, the melt cache unit includes a melt cache tank with temperature control.

[0020] Preferably, the jet flash tank and the melt 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).

[0021] As a preferred technical solution of the present invention, the polyethylene wax multi-stage 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] As a preferred technical solution of the present invention, the jet flash unit comprises a flash tank, and the flash tank is equipped with a spray mechanism for forming a spray film from the molten pressurized polyethylene wax.

[0026] As a preferred technical solution of the present invention, the flash tank is a vacuum flash tank;

[0027] And / or, the spraying mechanism includes an atomizing nozzle or a spray head.

[0028] And / or, the spraying mechanism is a rotary atomizing nozzle.

[0029] Compared with the prior art, the present invention has the following innovative features:

[0030] The present invention forms a liquid phase particle film from the molten polyethylene wax through a spray mechanism, and quickly flash evaporates 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. The 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, it has low energy consumption, does not need to introduce water vapor, reduces the dehydration step, and 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 parameters such as temperature and pressure during the flash evaporation process, the separation process can be accurately controlled.

[0031] In addition, 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

[0032] 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;

[0033] Figure 2 This is a schematic diagram of the structure of the rotary atomizing nozzle used in Example 2 of the present invention;

[0034] Figure 3 for Figure 2 Explosion diagram of

[0035] Reference numerals:

[0036] 100-Raw material tank;

[0037] 201-first melting cache tank; 202-second melting cache tank; 203-third melting cache tank;

[0038] 301-first jet flash tank; 302-second jet flash tank; 303-third jet flash tank;

[0039] 400-injection mechanism; 401-outer sleeve; 402-rotating connecting pipe; 403-multi-hole nozzle; 4031-opening; 404-ball bearing assembly; 405-internal thread connector;

[0040] 500 - condensation separation unit; 501 - first condensation tank; 502 - second condensation tank; 503 - third condensation tank; 504 - tail gas absorption tank. DETAILED DESCRIPTION

[0041] 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.

[0042] 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 multi-stage separation and refining system, which can efficiently and concisely obtain a variety of high-value products.

[0043] The specific technical scheme of the present invention is:

[0044] A polyethylene wax multi-stage separation and refining system is provided with at least one group of jet flash evaporation units, at least one group of melt buffer units and at least one group of condensation separation units, wherein the jet flash evaporation unit is used to form a spray film of molten pressurized polyethylene wax for flash separation, the melt buffer unit is connected to the inlet of the jet flash evaporation unit through a pipeline, and is used to buffer and supply molten polyethylene wax, and the condensation separation unit is connected to the top outlet of the jet flash evaporation unit through a pipeline, and is used to condense the light component gas phase material obtained by flash separation.

[0045] As a specific preferred embodiment of the present invention, a plurality of groups of jet flash evaporation units are provided, and the plurality of groups of jet flash evaporation units are connected in parallel or in series. When the jet flash evaporation units are connected in parallel, the material processing capacity and the production capacity can be improved; when the jet flash evaporation units are connected in series, deep-level step-by-step separation can be achieved, thereby improving the separation accuracy.

[0046] As a specific preferred embodiment of the present invention, the jet flash unit is provided with 2 to 6 groups, preferably 3 to 4 groups. For example, by connecting 2, 3, 4 or 5 groups of jet flash units in series and / or in parallel, a complex refining and separation system is constructed to achieve efficient separation of the product.

[0047] As a specific preferred embodiment of the present invention, a plurality of groups of jet flash evaporation units are connected in series to form a multi-stage separation system, and the melt buffer unit is arranged between two adjacent jet flash evaporation units to buffer the heavy component materials after flash evaporation in the upstream jet flash evaporation unit and reserve raw materials for the next stage jet flash evaporation unit.

[0048] As a specific preferred embodiment of the present invention, the temperature of the jet flash evaporation unit increases step by step along the material flow direction, the temperature difference between adjacent melt buffer units is 2 to 10°C, preferably 3 to 5°C, the temperature of the melt buffer unit is the same as the temperature of the jet flash evaporation unit connected downstream thereof, and by setting multiple groups of jet flash evaporation units with gradually increasing temperatures, the components in the polyethylene wax can be separated step by step, and products with higher application value can be cut out.

[0049] As a specific preferred embodiment of the present invention, a booster delivery pump is provided between the melt buffer unit and the jet flash unit, and the flow rate and pressure of the molten polyethylene wax can be controlled by setting the parameters of the booster delivery pump.

[0050] As a specific preferred embodiment of the present invention, the jet flash unit includes a jet flash tank with temperature control, and the melt cache unit includes a melt cache tank with temperature control. Preferably, the jet flash tank and the melt cache tank are provided with heat exchange jackets, and the temperature is controlled by introducing a heat exchange medium (such as superheated steam or heat transfer oil).

[0051] As a specific preferred embodiment of the present invention, the polyethylene wax multi-stage separation and refining system also includes a raw material tank, the outlet of the raw material tank is connected to the inlet of the melting buffer unit through a pipeline, and the raw material tank is used to store the initial polyethylene wax raw material to be processed.

[0052] As a specific preferred embodiment 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, for example, 2, 3 or 4 condensation tanks are used, and multiple condensation tanks are connected in series in sequence, and the condensation temperature is gradually reduced. 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 reduced 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 polyethylene wax oil products with higher application value.

[0053] As a specific preferred embodiment of the present invention, the condenser is connected to a vacuum pump, and a vacuum condenser is formed by vacuuming the vacuum pump, and the end of the condensation separation unit is connected to the tail gas treatment equipment. 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.

[0054] As a specific preferred embodiment of the present invention, the jet flash unit includes a flash tank, which is equipped with a spray mechanism for forming a spray film from molten pressurized polyethylene wax. Preferably, the flash tank is a vacuum flash tank, and the spray mechanism includes an atomizing nozzle or a spray head. Further preferably, the spray mechanism is a rotary atomizing nozzle.

[0055] Example 1

[0056] Reference Figure 1 The schematic diagram of the polyethylene wax multi-stage separation and refining system shown in the figure comprises three groups of jet flash evaporation units, three groups of melt buffer units and three groups of condensation separation units. The melt buffer units and the jet flash evaporation units are connected in series in sequence. The condensation separation unit is arranged at the top outlet of the jet flash evaporation unit to condense the light component gas phase material obtained by flash separation.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] Example 2

[0062] Compared with Example 1, the spray mechanism adopted in this embodiment is specifically 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.

[0063] 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.

[0064] 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.

[0065] 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 multi-stage separation and refining system, characterized in that: include: At least one set of jet flash evaporation units, used for forming the molten pressurized polyethylene wax into a spray film for flash evaporation separation; At least one set of condensation separation units is connected to the top outlet of the jet flash unit through a pipeline and is used to condense the light component gas phase material obtained by flash separation.

2. A polyethylene wax multi-stage separation and refining system according to claim 1, characterized in that: The jet flash unit is provided with a plurality of groups, which are connected in parallel and / or in series.

3. A polyethylene wax multi-stage separation and refining system according to claim 2, characterized in that: The jet flash units are provided with 2 to 6 groups, preferably 3 to 4 groups, which are connected in series.

4. A polyethylene wax multi-stage separation and refining system according to claim 3, characterized in that: Also includes: At least one group of melt buffer units, connected to the inlet of the jet flash unit through a pipeline, for buffering and supplying molten polyethylene wax; The melt buffer unit is arranged between two adjacent jet flash units; 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; The temperature of the melt buffer unit is the same as the temperature of the jet flash unit connected downstream thereof.

5. A polyethylene wax multi-stage separation and refining system according to claim 4, characterized in that: A booster delivery pump is provided between the melt buffer unit and the jet flash unit; and / or, the jet flash unit comprises a jet flash tank with temperature control; And / or, the melt cache unit includes a melt cache tank with temperature control.

6. A polyethylene wax multi-stage separation and refining system according to claim 4, characterized in that: The polyethylene wax multi-stage separation and refining system also includes a raw material tank, and the outlet of the raw material tank is connected to the inlet of the melting buffer unit through a pipeline.

7. A polyethylene wax multi-stage separation and refining system according to claim 1, characterized in that: The condensation separation unit comprises 1 to 5 stages of condensation tanks, preferably 2 to 4 stages of condensation tank groups, wherein the 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.

8. A polyethylene wax multi-stage separation and refining system according to claim 7, characterized in that: The condensation tank is connected to a vacuum pump, and a vacuum condensation tank is formed by vacuuming the tank with the vacuum pump. The end of the condensation separation unit is connected to an exhaust gas treatment device.

9. A polyethylene wax multi-stage separation and purification system according to any one of claims 1 to 8, characterized in that: The jet flash unit comprises a flash tank, and the flash tank is equipped with a spray mechanism for forming a spray film from molten pressurized polyethylene wax.

10. A polyethylene wax multi-stage separation and refining system according to claim 9, characterized in that: The flash tank is a vacuum flash tank; and / or, the spraying mechanism comprises an atomizing nozzle or a spray head; And / or, the spraying mechanism is a rotary atomizing nozzle.

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