阅读说明：本技术 一种炼油装置汽提塔防结盐腐蚀装置及方法 (Device and method for preventing salt deposition corrosion of stripping tower of oil refining device ) 是由 曾庆峰 孙会东 王新平 邢定峰 张晓华 吕青龙 边刚月 李军 赵金海 孙宝文 杨 于 2020-11-06 设计创作，主要内容包括：本发明公开了一种炼油装置汽提塔防结盐腐蚀装置及方法,属于石油化工领域。该装置包括：汽提塔、塔顶回流罐、循环泵、过滤器、增压泵、气液混合器、油水分离器；汽提塔的塔顶出口、塔顶回流罐、循环泵的进口依次连通；循环泵的出口、过滤器、增压泵、气液混合器、油水分离器依次连通；循环泵的出口、气液混合器的气相出口、油水分离器的油相出口均与汽提塔的上部回流口连通。该装置最大程度地消除了腐蚀介质对炼油装置汽提塔的影响,获得了良好的防结盐腐蚀效果,且具有较低的成本。(The invention discloses a device and a method for preventing salt deposition corrosion of a stripping tower of an oil refining device, and belongs to the field of petrochemical industry. The device includes: the device comprises a stripping tower, a tower top reflux tank, a circulating pump, a filter, a booster pump, a gas-liquid mixer and an oil-water separator; the tower top outlet of the stripping tower, the tower top reflux tank and the inlet of the circulating pump are communicated in sequence; the outlet of the circulating pump, the filter, the booster pump, the gas-liquid mixer and the oil-water separator are communicated in sequence; the outlet of the circulating pump, the gas phase outlet of the gas-liquid mixer and the oil phase outlet of the oil-water separator are communicated with the upper part return port of the stripping tower. The device furthest has eliminated the influence of corruption medium to oil refining device stripper, has obtained good salt deposition corrosion prevention effect, and has lower cost.)

1. An apparatus for preventing salt corrosion from occurring in a stripping tower of an oil refining apparatus, the apparatus comprising: the device comprises a stripping tower, a tower top reflux tank, a circulating pump, a filter, a booster pump, a gas-liquid mixer and an oil-water separator;

an outlet at the top of the stripping tower, the reflux tank at the top of the stripping tower and an inlet of the circulating pump are communicated in sequence;

the outlet of the circulating pump, the filter, the booster pump, the gas-liquid mixer and the oil-water separator are communicated in sequence;

and the outlet of the circulating pump, the gas phase outlet of the gas-liquid mixer and the oil phase outlet of the oil-water separator are communicated with the upper part return port of the stripping tower.

2. The refinery stripper salt corrosion prevention apparatus of claim 1, wherein the filter comprises: the device comprises an outer shell, a membrane component, a back-blowing gas inlet, a treatment liquid inlet, an impurity outlet and a filtrate outlet;

the shell body comprises a top cover, a shell body and a bottom cover which are sequentially communicated from top to bottom, and the membrane assembly is positioned in the shell body;

the back-blowing gas inlet is positioned on the top cover;

the treatment liquid inlet and the filtrate outlet are respectively positioned at the lower part and the upper part of the shell body;

the impurity outlet is positioned on the bottom cover.

3. The stripping tower salt deposition corrosion prevention device of an oil refining device according to claim 2, wherein the aperture of the filtering membrane adopted by the membrane module is 25 nm-55 nm.

4. The refinery plant stripping column salt deposit corrosion prevention device of claim 1, wherein the gas-liquid mixer is a loop mixer for enhancing gas-liquid mixing.

5. The refinery plant stripping column salt deposit corrosion prevention device of claim 4, wherein the gas-liquid mixer comprises: the device comprises a mixer shell, a hydrocyclone separator, a guide cylinder, a washing water inlet, a tower return oil inlet, a mixer gas-phase outlet and a mixer liquid-phase outlet;

the guide cylinder and the hydrocyclone separator are both positioned in the mixer shell, and the hydrocyclone separator is positioned above the guide cylinder; the washing water inlet, the mixer gas-phase inlet, the mixer liquid-phase outlet and the tower return oil inlet are all positioned at the bottom of the mixer shell;

the mixer gas phase outlet is located at the top of the mixer housing.

6. The refinery plant stripping column salt corrosion prevention device of claim 5, wherein an ejector is provided at the return oil inlet;

the bottom wall of the ejector is provided with a first inlet, and the first inlet is used for enabling tower returning oil to enter;

the side wall of the ejector is provided with a second inlet which is communicated with the washing water inlet through a pipeline;

and the side wall of the ejector is provided with a third inlet which is communicated with the mixer gas-phase inlet through a pipeline.

7. The refinery plant stripping column salt deposit corrosion prevention device of claim 5, wherein the ratio of the effective flow guide area of the flow guide cylinder to the effective cross-sectional area of the mixer housing is 0.25-0.8: 1.

8. The stripping column salt deposition corrosion preventing apparatus for an oil refinery according to claim 1, wherein said oil-water separator comprises: the separator comprises a separator shell, a hydrophobic lipophilic film, a liquid inlet, a water outlet and an oil phase outlet;

the hydrophobic oleophilic film is positioned inside the separator shell;

the liquid inlet and the oil phase outlet are respectively positioned at the upper part of the separator shell;

the drain opening is located at a lower portion of the separator housing.

9. A method for preventing salt corrosion of a stripping tower of an oil refinery, wherein the treatment method employs the stripping tower salt corrosion prevention device of any one of claims 1 to 8, comprising:

condensing part of tower top gas phase of a stripping tower of the oil refining device, then feeding the condensed gas phase into a tower top reflux tank, returning part of tower return oil from the tower top reflux tank to the stripping tower of the oil refining device through a circulating pump, filtering the other part of tower return oil through a filter, and pressurizing the filtered tower return oil through a booster pump;

simultaneously feeding the pressurized tower return oil, the other part of tower top gas phase of the stripping tower and the washing water into a gas-liquid mixer for gas-liquid mixing, so that corrosive media in the pressurized tower return oil and the tower top gas phase are transferred into the washing water;

and returning the gas phase obtained by the gas-liquid mixer to the oil refining device stripping tower, allowing the liquid phase obtained by the gas-liquid mixer to enter an oil-water separator for oil-water separation to obtain target tower returning oil for removing the corrosive medium and external drainage containing the corrosive medium, and returning the target tower returning oil to the oil refining device stripping tower.

10. The refinery plant stripping tower salt corrosion prevention method according to claim 9, wherein the flow velocity of the pressurized return tower oil is 2m/s-10m/s when the pressurized return tower oil enters the gas-liquid mixer.

Technical Field

The invention relates to the field of petrochemical industry, in particular to a salt deposition corrosion prevention device of a stripping tower of an oil refining device and a treatment method.

Background

The residual oil hydrogenation device provides raw materials for a catalytic cracking device and increases the yield of high value-added products by processing high-salt and high-metal-containing residual oil, and the problems of serious salt deposition and blockage of a stripping tower and equipment corrosion of the stripping tower are more and more concerned while the residual oil hydrogenation device becomes an important measure for improving the economic benefit of an oil refinery.

Residual oil carries N, S, Cl and other elements and a certain amount of solid impurities, and after entering a reactor, NH is easily generated by reaction at high temperature₃、H₂S, HCl, low temperature, NH₃Reaction with HCl produced NHCl ammonium salt particles, which were prone to deposition with solid impurities. The hot low-fraction oil from the reactor (with the above-mentioned solid impurities and suspended matter) is mixed with the cold low-fraction oil after heat exchange and fed into a stripping tower, in which the temp. is reduced and the steam is evaporatedResulting in the formation of large quantities of corrosive media, such as salts and acidic solutions, which accumulate to a certain extent and cause severe salt formation corrosion at the top of the stripper.

Currently, the above corrosion problem is generally improved by the following measures: and injecting a corrosion inhibitor into a top pipeline of the stripping tower, and performing water injection and washing on the stripping tower, or upgrading the material of tower top equipment of the stripping tower and the like.

In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art:

the solution provided by the prior art not only has poor improvement effect on the corrosion problem, but also obviously increases the operation cost.

Disclosure of Invention

In view of the above, the present invention provides a device for preventing corrosion of stripping tower of oil refining apparatus from salt deposition and a processing method thereof, which can solve the above technical problems.

Specifically, the method comprises the following technical scheme:

in one aspect, there is provided an apparatus for preventing salt corrosion in a stripping tower of an oil refinery, the apparatus for preventing salt corrosion in a stripping tower of an oil refinery comprising: the device comprises a stripping tower, a tower top reflux tank, a circulating pump, a filter, a booster pump, a gas-liquid mixer and an oil-water separator;

an outlet at the top of the stripping tower, the reflux tank at the top of the stripping tower and an inlet of the circulating pump are communicated in sequence;

the outlet of the circulating pump, the filter, the booster pump, the gas-liquid mixer and the oil-water separator are communicated in sequence;

and the outlet of the circulating pump, the gas phase outlet of the gas-liquid mixer and the oil phase outlet of the oil-water separator are communicated with the upper part return port of the stripping tower.

In some possible implementations, the filter includes: the device comprises an outer shell, a membrane component, a back-blowing gas inlet, a treatment liquid inlet, an impurity outlet and a filtrate outlet;

the shell body comprises a top cover, a shell body and a bottom cover which are sequentially communicated from top to bottom, and the membrane assembly is positioned in the shell body;

the back-blowing gas inlet is positioned on the top cover;

the treatment liquid inlet and the filtrate outlet are respectively positioned at the lower part and the upper part of the shell body;

the impurity outlet is positioned on the bottom cover.

In some possible implementations, the membrane module employs a filtration membrane having a pore size of 25 nm to 55 nm.

In some possible implementations, the gas-liquid mixer is a loop mixer for enhancing gas-liquid mixing.

In some possible implementations, the gas-liquid mixer includes: the device comprises a mixer shell, a hydrocyclone separator, a guide cylinder, a washing water inlet, a tower return oil inlet, a mixer gas-phase outlet and a mixer liquid-phase outlet;

the guide cylinder and the hydrocyclone separator are both positioned in the mixer shell, and the hydrocyclone separator is positioned above the guide cylinder;

the washing water inlet, the mixer gas-phase inlet, the mixer liquid-phase outlet and the tower return oil inlet are all positioned at the bottom of the mixer shell;

the mixer gas phase outlet is located at the top of the mixer housing.

In some possible implementations, an ejector is provided at the return tower oil inlet;

the bottom wall of the ejector is provided with a first inlet, and the first inlet is used for enabling tower returning oil to enter;

the side wall of the ejector is provided with a second inlet which is communicated with the washing water inlet through a pipeline;

and the side wall of the ejector is provided with a third inlet which is communicated with the mixer gas-phase inlet through a pipeline.

In some possible implementations, a ratio of an effective flow guide area of the flow guide cylinder to an effective cross-sectional area of the mixer housing is 0.25-0.8: 1.

In some possible implementations, the oil-water separator includes: the separator comprises a separator shell, a hydrophobic lipophilic film, a liquid inlet, a water outlet and an oil phase outlet;

the hydrophobic oleophilic film is positioned inside the separator shell;

the liquid inlet and the oil phase outlet are respectively positioned at the upper part of the separator shell;

the drain opening is located at a lower portion of the separator housing.

On the other hand, the embodiment of the invention also provides a method for preventing the stripping tower of the oil refining device from salt deposition corrosion, wherein the treatment method adopts any one of the stripping tower salt deposition corrosion prevention devices of the oil refining device, which comprises the following steps:

condensing part of tower top gas phase of a stripping tower of the oil refining device, then feeding the condensed part of tower top gas phase into a tower top reflux tank, returning part of tower return oil from the tower top reflux tank to the stripping tower of the oil refining device through a circulating pump, filtering the other part of tower return oil through a filter, and pressurizing the filtered tower return oil through a pressurizing pump to obtain pressurized tower return oil;

simultaneously feeding the pressurized tower return oil, the other part of tower top gas phase of the stripping tower and the washing water into a gas-liquid mixer for gas-liquid mixing, so that corrosive media in the pressurized tower return oil and the tower top gas phase of the stripping tower of the oil refining device are transferred into the washing water;

and returning the gas phase obtained by the gas-liquid mixer to the stripping tower, allowing the liquid phase obtained by the gas-liquid mixer to enter an oil-water separator for oil-water separation to obtain target tower returning oil for removing the corrosive medium and external drainage containing the corrosive medium, and returning the target tower returning oil to the stripping tower.

In some possible implementation manners, when the pressurized tower oil enters the gas-liquid mixer, the flow speed of the pressurized tower oil is 2m/s-10 m/s.

The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:

the device for preventing the salt corrosion of the stripping tower provided by the embodiment of the invention can be used for removing the corrosion medium in the gas phase at the top of the stripping tower of the oil refining device on line. During application, the gas phase at the top of the stripping tower is condensed and then enters the tower top reflux tank, part of tower return oil from the tower top reflux tank returns to the stripping tower through the circulating pump, the other part of tower return oil is filtered through the filter, and the filtered tower return oil is pressurized through the booster pump and enters the ejector. The pressurized tower return oil, the other part of tower top gas phase of the stripping tower and the washing water simultaneously enter a gas-liquid mixer through an ejector to be subjected to gas-liquid mixing, so that corrosive media in the pressurized tower return oil and the tower top gas phase of the stripping tower are transferred to the washing water; and returning the gas phase obtained by the gas-liquid mixer to the stripping tower, allowing the liquid phase obtained by the gas-liquid mixer to enter an oil-water separator for oil-water separation to obtain target tower returning oil with the corrosive medium removed and the discharged water containing the corrosive medium, and returning the target tower returning oil to the stripping tower. Therefore, the oil refining device stripping tower salt deposition corrosion prevention device provided by the embodiment of the invention performs three-stage treatment on the corrosion medium and other solid impurities in the tower returning oil phase and the tower returning gas phase of the stripping tower through the filter, the gas-liquid mixer and the oil-water separator, so that the influence of the corrosion medium on the stripping tower of the oil refining device is eliminated to the greatest extent, a good salt deposition corrosion prevention effect is obtained, and the cost is low.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a stripping tower salt corrosion prevention device for an oil refinery apparatus according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a filter according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a gas-liquid mixer according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an oil-water separator provided in an embodiment of the present invention.

The reference numerals denote:

1-a stripping tower, wherein the stripping tower comprises a tower body,

2-a reflux tank at the top of the tower,

3-a circulating pump is arranged in the device,

4-a filter is arranged on the upper surface of the filter,

401-outer shell, 402-membrane module, 403-back-flushing gas inlet,

404-treatment fluid inlet, 405-impurity outlet, 406-filtrate outlet,

5-a booster pump is arranged at the lower part of the device,

6-a gas-liquid mixer, wherein,

601-mixer shell, 602-hydrocyclone, 603-guide shell,

604-washing water inlet, 605-tower oil inlet, 606-mixer gas phase inlet,

607-mixer gas phase outlet, 608-mixer liquid phase outlet, 609-ejector,

7-an oil-water separator, wherein,

701-a separator shell, 702-a hydrophobic oleophilic film, 703-a liquid inlet,

704-drainage port, 705-oil phase outlet.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the following will describe embodiments of the present invention in further detail with reference to the accompanying drawings.

In one aspect, an embodiment of the present invention provides an apparatus for preventing salt corrosion in a stripping tower of an oil refining apparatus, as shown in fig. 1, the apparatus for preventing salt corrosion in a stripping tower of an oil refining apparatus includes: a stripping tower 1, a tower top reflux tank 2, a circulating pump 3, a filter 4, a booster pump 5, a gas-liquid mixer 6 and an oil-water separator 7;

the outlet of the top of the stripping tower 1, the reflux tank 2 at the top of the stripping tower and the inlet of the circulating pump 3 are communicated in sequence;

an outlet of the circulating pump 3, the filter 4, the booster pump 5, the gas-liquid mixer 6 and the oil-water separator 7 are communicated in sequence;

the outlet of the circulating pump 3, the gas phase outlet of the gas-liquid mixer 6 and the oil phase outlet 705 of the oil-water separator 7 are all communicated with the upper part return port of the stripping tower 1.

Wherein, the top of the stripping tower 1 is provided with a tower top outlet for discharging a tower top gas phase; the upper part of the stripping column 1 has an upper reflux port which is located below the top outlet and above the stripping section of the stripping column 1, for returning the tower return oil returned to the stripping column 1.

The oil refining device stripping tower salt corrosion prevention device provided by the embodiment of the invention can be used for removing a corrosion medium in a tower top gas phase of the stripping tower 1 on line. During application, a part of tower top gas phase of the stripping tower 1 is condensed and then enters the tower top reflux tank 2, part of tower return oil from the tower top reflux tank 2 returns to the stripping tower 1 through the circulating pump 3, the other part of tower return oil is filtered through the filter 4, and the filtered tower return oil is pressurized through the booster pump 5 to obtain pressurized tower return oil. The pressurized tower return oil, the other part of the tower top gas phase of the stripping tower 1 and the washing water simultaneously enter a gas-liquid mixer 6 for gas-liquid mixing, so that the pressurized tower return oil and the corrosive medium in the tower top gas phase of the stripping tower 1 are transferred into the washing water; the gas phase obtained by the gas-liquid mixer 6 returns to the stripping tower 1, the liquid phase obtained by the gas-liquid mixer 6 enters the oil-water separator 7 for oil-water separation, the target tower returning oil from which the corrosive medium is removed and the external drainage containing the corrosive medium are obtained, and the target tower returning oil is returned to the stripping tower 1. Therefore, according to the oil refining device stripping tower salt deposition corrosion prevention device provided by the embodiment of the invention, the filter 4, the gas-liquid mixer 6 and the oil-water separator 7 are used for carrying out three-stage treatment on the corrosion medium and other solid impurities in the tower return oil phase and the tower return gas phase of the stripping tower 1 of the oil refining device, so that the influence of the corrosion medium on the stripping tower 1 is eliminated to the greatest extent, a good salt deposition corrosion prevention effect is obtained, and the cost is low.

The following description is made of the structural arrangement and the function of each component included in the stripping tower salt corrosion prevention device for an oil refining device provided by the embodiment of the present invention, respectively:

(1) for the filter 4

In some possible implementations, as shown in fig. 2, the filter 4 provided in the embodiment of the present invention includes: an outer shell 401, a membrane module 402, a blowback gas inlet 403, a treatment liquid inlet 404, an impurity outlet 405 and a filtrate outlet 406.

The outer shell 401 comprises a top cover, an outer shell body and a bottom cover which are sequentially communicated from top to bottom, and the membrane assembly 402 is positioned in the outer shell body;

a blowback gas inlet 403 is positioned on the top cover; the treatment fluid inlet 404 and the filtrate outlet 406 are located at the lower and upper portions of the housing body, respectively; an impurity outlet 405 is located on the bottom cover.

In application, a part of the tower return oil from the tower top reflux tank 2 is conveyed to the treatment liquid inlet 404 through the circulating pump 3 and enters the interior of the outer shell 401, and the tower return oil is subjected to filtration treatment through the membrane module 402 so as to remove most of solids and suspended matters in the tower return oil. The obtained filtered tower returning oil is discharged through a filtrate outlet 406, and the obtained filtered impurities are discharged through an impurity outlet 405.

During the filtration process, a blowback gas, such as nitrogen, enters the interior of the outer shell 401, and the resulting pressure pulsation removes impurities from the membrane modules 402 to ensure that the membrane modules 402 maintain a stable filtration flux. And in the filtering process, the filtering pressure drop is kept to be 0.03-0.3 MPa so as to further optimize the effect.

In one possible implementation, the membrane module 402 uses a filter membrane with a pore size of 25 nm-55 nm and a thickness of 3-80 μm, so as to obtain a better filtering effect, and remove solid impurities and suspended impurities in the oil returned to the tower as much as possible. Wherein the filter membrane includes, but is not limited to: polyphenylene sulfide and the like.

(2) For gas-liquid mixer 6

In the embodiment of the invention, another part of the overhead gas phase extracted from the overhead extraction line of the stripping tower 1 and the filtered return tower oil are washed and desalted by the gas-liquid mixer 6, and the salt corrosion medium contained in the overhead gas phase is transferred to the washing water.

In some possible implementations, in order to enhance the mass transfer effect of the gas-liquid mixture, the gas-liquid mixer 6 used is a loop mixer for enhancing the gas-liquid mixture.

Illustratively, as shown in fig. 3, the gas-liquid mixer 6 provided by the embodiment of the present invention includes: mixer housing 601, hydrocyclone 602, draft tube 603, wash water inlet 604, return tower oil inlet 605, mixer gas phase inlet 606, mixer gas phase outlet 607, mixer liquid phase outlet 608.

The guide shell 603 and the hydrocyclone 602 are both positioned inside the mixer shell 601, and the hydrocyclone 602 is positioned above the guide shell 603; the washing water inlet 604, the mixer gas-phase inlet 606, the mixer liquid-phase outlet 608 and the tower return oil inlet 605 are all positioned at the bottom of the mixer shell 601; mixer gas phase outlet 607 is located at the top of mixer housing 601.

When the device is used, washing water (for example, demineralized water) enters the mixer shell 601 through the washing water inlet 604, pressurized tower return oil enters the mixer shell 601 through the tower return oil inlet 605, a tower top gas phase of the stripping tower 1 enters the mixer shell 601 through the mixer gas phase inlet 606, the three are mixed in a gas-liquid mode, and multiple circulation mixing is achieved through the guide cylinder 603. The hydrocyclone 602 is used to separate a gas phase from a small amount of liquid carried by the gas phase, and the separated gas phase is discharged through a mixer gas phase outlet 607 and returned to the stripper column 1.

In the embodiment of the invention, an annular gap channel is formed between the outer wall of the guide cylinder 603 and the inner wall of the mixer housing 601, the guide cylinder 603 is fixed on the inner wall of the mixer housing 601 through a support plate in the annular gap channel, and two ends of the guide cylinder 603 are open.

The guide shell 603 is a cylindrical structure with openings at the upper end and the lower end, the inner part of the mixer shell 601 is divided into an inner ring area and an outer ring area (the inner ring area is an inner cavity of the guide shell 603, and the outer ring area is an annular gap between the guide shell 603 and the mixer shell 601).

At least one stage of guide cylinder 603 is arranged in the gas-liquid mixer 6, the height of each stage of guide cylinder 603 is 400-20000 mm, and the ratio of the effective flow guide area of the guide cylinder 603 to the effective sectional area of the mixer shell 601 is 0.25-0.8: 1. The effective flow guide area of the guide shell 603 refers to the sectional area of the inner cavity of the guide shell 603; the effective cross-sectional area of mixer housing 601 refers to the cross-sectional area of the internal cavity of mixer housing 601.

In some possible implementations, an ejector 609 is provided at the tower return oil inlet 605, and a first inlet is provided on a bottom wall of the ejector 609, and the first inlet is used for the tower return oil to enter; the ejector 609 has a second inlet on a sidewall thereof, the second inlet being communicated with the washing water inlet 604 through a pipe; the ejector 609 has a third inlet in the side wall, which communicates with the mixer gas phase inlet 606 via a conduit.

Through the arrangement of the ejector 609, pressurized tower return oil is sprayed in from the first inlet, pressure energy is converted into velocity energy at the second inlet and the third inlet due to high spraying velocity, then the pressure is reduced, vacuum is generated, washing water and gas phase at the top of the tower from the stripping tower 1 are respectively introduced from the second inlet and the third inlet, the washing water and the gas phase at the top of the tower from the stripping tower 1 are firstly mixed in a gas-liquid turbulent flow mode in the ejector 609 and are sprayed into the guide cylinder 603 through the ejector 609 to be mixed in a gas-liquid circular flow mode again, and a better gas-liquid mixing effect can be obtained through the arrangement. That is, the washing and desalting processes performed by the gas-liquid mixer 6 are sequentially realized by the gas-liquid turbulent mixing action of the ejector 609 and the gas-liquid circulating action of the guide cylinder 603.

Further, the flow velocity of the tower return oil in the ejector 609 is 2m/s-10m/s, so that the ejector 609 can use the tower return oil as a power source, and simultaneously provide enough suction for the washing water and the tower top gas phase, thereby being beneficial to the sufficient and uniform mixing of the three.

The outlet of the ejector 609 is located at the top thereof, wherein the outlet of the ejector 609 is provided in a micropore shape, for example, the diameter of the micropore is 50 μm-1000 μm, so that the gas-liquid mixed fluid ejected by the ejector 609 can form micro bubbles inside the mixer housing 601, and the micro bubbles also have ejection kinetic energy due to the ejection effect, and regular circulation flow can be formed due to the liquid and the density difference between the inner ring and the outer ring of the mixer housing 601 due to the ejection kinetic energy, and the bubbles promote oil-water mixing and desalination, thereby obtaining better desalination effect.

(3) For the oil-water separator 7

In the embodiment of the invention, the oil-water separator 7 is used, so that the liquid phase (oil-water mixture) obtained by the gas-liquid mixer 6 enters the oil-water separator 7 for oil-water separation, and the target tower returning oil for removing the corrosive medium and the external drainage containing the corrosive medium are obtained.

In some possible implementations, as shown in fig. 4, the oil-water separator 7 includes: a separator shell 701, a hydrophobic oleophilic film 702, a liquid inlet 703, a water outlet 704 and an oil phase outlet 705; the hydrophobic oleophilic film 702 is located inside the separator shell 701, specifically, as shown in fig. 4, the hydrophobic oleophilic film 702 is vertically arranged along the axial section of the oil-water separator 7, when an oil-water mixture passes through the hydrophobic oleophilic film 702, oil passes through the hydrophobic oleophilic film 702, and water containing corrosive media is intercepted; the liquid inlet 703 and the oil phase outlet 705 are respectively positioned at the upper part of the separator shell 701; the drain 704 is located at a lower portion of the separator housing 701.

When the device is used, an oil-water mixture from the gas-liquid mixer 6 enters the separator shell 701 from the liquid inlet 703, water in the oil-water mixture is intercepted by the hydrophobic oleophilic oil film 702, wherein the separated water phase is discharged through the water outlet 704, and the separated oil phase returns to the stripping tower 1 through the oil phase outlet 705.

In the embodiment of the present invention, the hydrophobic lipophilic film 702 includes: the contact angle of the hydrophobic oleophilic film layer to water is about 153-160 degrees, and the contact angle to oil products such as diesel oil, naphtha is about 0 degree.

In some possible implementations, the substrate layer is a micron-sized stainless steel plate substrate; the hydrophobic oleophilic film 702 layer is a poly (arylene ether nitrile) -graphene composite coating, the hydrophobic oleophilic film 702 layer has excellent repellency to high-acidity and salt-containing solutions, and the separation efficiency to water-in-oil emulsion is more than 99.9%.

In the embodiment of the present invention, all the internal components, such as the hydrocyclone 602, the guide cylinder 603, the injector 609, and the like, may be coated with a corrosion-resistant and wear-resistant coating to protect the surfaces of the components in order to improve corrosion resistance and wear resistance.

In a possible implementation manner, an embodiment of the present invention provides a stripping tower salt corrosion prevention processing apparatus, including: the device comprises a stripping tower 1, a tower top reflux tank 2, a circulating pump 3, a filter 4, a booster pump 5, a gas-liquid mixer 6 and an oil-water separator 7.

Wherein, the top of the stripping tower 1 is provided with a tower top outlet for leading out a tower top gas phase; the upper part of the stripping column 1 has an upper reflux port which is located below the top outlet and above the stripping section of the stripping column 1, for returning the tower return oil returned to the stripping column 1.

The outlet of the top of the stripping tower 1, the reflux tank 2 at the top of the stripping tower and the inlet of the circulating pump 3 are communicated in sequence; an outlet of the circulating pump 3, the filter 4, the booster pump 5, the gas-liquid mixer 6 and the oil-water separator 7 are communicated in sequence; the outlet of the circulating pump 3, the gas phase outlet of the gas-liquid mixer 6 and the oil phase outlet 705 of the oil-water separator 7 are all communicated with the upper part return port of the stripping tower 1.

Specifically, the filter 4 includes: an outer shell 401, a membrane module 402, a blowback gas inlet 403, a treatment liquid inlet 404, an impurity outlet 405 and a filtrate outlet 406. The outer shell 401 comprises a top cover, an outer shell body and a bottom cover which are sequentially communicated from top to bottom, and the membrane assembly 402 is positioned in the outer shell body; a blowback gas inlet 403 is positioned on the top cover; the treatment fluid inlet 404 and the filtrate outlet 406 are located at the lower and upper portions of the housing body, respectively; an impurity outlet 405 is located on the bottom cover. The pore diameter of the filtration membrane used in the membrane module 402 is 25 nm to 55 nm.

The gas-liquid mixer 6 includes: mixer housing 601, hydrocyclone 602, draft tube 603, wash water inlet 604, return tower oil inlet 605, mixer gas phase inlet 606, mixer gas phase outlet 607, mixer liquid phase outlet 608.

The guide shell 603 and the hydrocyclone 602 are both positioned inside the mixer shell 601, and the hydrocyclone 602 is positioned above the guide shell 603; the washing water inlet 604, the mixer gas-phase inlet 606, the mixer liquid-phase outlet 608 and the tower return oil inlet 605 are all positioned at the bottom of the mixer shell 601; mixer gas phase outlet 607 is located at the top of mixer housing 601.

An ejector 609 is arranged at the tower return oil inlet 605, and a first inlet is formed in the bottom wall of the ejector 609 and is used for enabling tower return oil to enter; the ejector 609 has a second inlet on a sidewall thereof, the second inlet being communicated with the washing water inlet 604 through a pipe; the ejector 609 has a third inlet in the side wall, which communicates with the mixer gas phase inlet 606 via a conduit.

As shown in fig. 4, the oil-water separator 7 includes: a separator shell 701, a hydrophobic oleophilic film 702, a liquid inlet 703, a water outlet 704 and an oil phase outlet 705; wherein, the hydrophobic oleophilic film 702 is located inside the separator housing 701; the liquid inlet 703 and the oil phase outlet 705 are respectively positioned at the upper part of the separator shell 701; the drain 704 is located at a lower portion of the separator housing 701.

The stripping tower salt corrosion prevention device can perform micro-bubble enhanced circulation mixing on the return tower oil and part of the tower top gas phase extracted by the stripping tower 1 so as to perform washing desalination and remove insoluble substances (solid, suspended substances and the like) in the return tower oil. The ejector 609 is used for ejecting the tower returning oil, the washing water and the gas phase at the top of the tower, the ejection kinetic energy carried by the ejector 609 and the internal and external ring density difference of the gas-liquid mixer 6 form regular liquid circulation flow, meanwhile, under the action of the micro-bubble reinforced mixing perturbation and the air flotation demulsification, the collision coalescence probability among oil drops and water drops is increased, salt in bubbles, oil in a water layer and saline in an oil layer are brought into an oil-water interface, the tower returning oil, the gas and the washing water are mixed intensively for multiple times, the salt and other corrosive media in the tower returning oil and the gas phase at the top of the tower are promoted to be transferred into the washing water, and finally, the oil-water high-efficiency separation is realized through the hydrophobic lipophilic film 702, so that the finally obtained corrosive media in the target tower.

Therefore, by using the device for preventing the salt corrosion of the stripping tower, provided by the embodiment of the invention, the returned tower oil and part of the corrosion medium in the gas phase at the top of the stripping tower can be efficiently removed on line, the influence of the corrosion medium on the stripping tower 1 is eliminated to the maximum extent, most of solid and suspended matters in the returned tower oil can be removed, and the possibility of mixed deposition of insoluble substances and ammonium salt and the adverse influence of the insoluble substances on long-period operation, heat transfer and mass transfer of the stripping tower, a heat exchanger and other equipment are reduced to the maximum extent. Therefore, the passive prevention and control of adding the corrosion inhibitor after salt deposition and upgrading the material of the equipment are changed into the active prevention and control before salt deposition, the problems of poor desalting effect, high cost or corrosion hidden danger and the like in the prior art are solved, and the safety, stability and long-period operation of the stripping tower can be effectively promoted.

On the other hand, based on any stripping tower salt corrosion prevention processing device provided by the embodiment of the invention, the embodiment of the invention also provides a stripping tower salt corrosion prevention method, and the processing method adopts any stripping tower salt corrosion prevention processing device.

In a possible implementation manner, the method for preventing salt deposition corrosion of a stripping tower provided by the embodiment of the present invention includes:

and partial tower top gas phase of the stripping tower 1 is condensed and then enters the tower top reflux tank 2 to be processed to obtain tower return oil, part of the tower return oil from the tower top reflux tank 2 returns to the stripping tower 1 through the circulating pump 3, the other part of the tower return oil is filtered through the filter 4, and the filtered tower return oil is pressurized through the booster pump 5.

The pressurized tower return oil, part of the tower top gas phase of the stripping tower 1 and the washing water simultaneously enter the gas-liquid mixer 6 for gas-liquid mixing, so that the pressurized tower return oil and the corrosion medium in the part of the tower top gas phase of the stripping tower 1 are transferred to the washing water.

The gas phase obtained by the gas-liquid mixer 6 returns to the stripping tower 1, the liquid phase obtained by the gas-liquid mixer 6 enters the oil-water separator 7 for oil-water separation, the target tower returning oil from which the corrosive medium is removed and the external drainage containing the corrosive medium are obtained, and the target tower returning oil is returned to the stripping tower 1.

For the filtering process performed in the filter 4, during the filtering process, the back-flushing nitrogen enters the inside of the outer shell 401 to remove impurities on the membrane module 402, so as to ensure that the membrane module 402 maintains a stable filtering flux. And in the filtering process, the pressure drop in the process is kept to be 0.03-0.3 MPa so as to further optimize the filtering effect. Wherein, the temperature of the tower returning oil is kept between 40 ℃ and 50 ℃.

For the gas-liquid mixing process performed in the gas-liquid mixer 6, the volume of the overhead gas phase extracted from the stripping tower 1 and entering the gas-liquid mixer 6 accounts for 2-45% of the total volume of the overhead gas phase extracted from the stripping tower 1; the volume of the pressurized tower return oil accounts for 5-55% of the total volume of the tower return oil discharged from the tower top reflux tank 2, and the volume of the washing water accounts for 0.3-15% of the volume of the pressurized tower return oil.

Particularly, when the pressurized tower returning oil enters the gas-liquid mixer 6, particularly when the pressurized tower returning oil enters the ejector 609 arranged at the tower returning oil inlet 605 of the gas-liquid mixer 6, the flow speed of the pressurized tower returning oil is 2m/s-10m/s, and by the arrangement, a proper jet flow speed can be obtained so as to carry sufficient kinetic energy and avoid the oil-water emulsification phenomenon.

For the oil-water separation process in the oil-water separator 7, the pressure drop in the oil-water separation process is 0.001MPa-0.15MPa, so as to obtain better oil-water separation effect.

The stripping tower salt corrosion prevention method provided by the embodiment of the invention can carry out micro-bubble enhanced circulation mixing on the tower return oil and part of the tower top gas phase extracted by the stripping tower 1 so as to carry out washing desalination and remove insoluble substances (solid, suspended substances and the like) in the tower return oil. The ejector 609 is used for ejecting the tower returning oil, the washing water and the gas phase at the top of the tower, the ejection kinetic energy carried by the ejector 609 and the internal and external ring density difference of the gas-liquid mixer 6 form regular liquid circulation flow, meanwhile, under the action of the micro-bubble reinforced mixing perturbation and the air flotation demulsification, the collision coalescence probability among oil drops and water drops is increased, salt in bubbles, oil in a water layer and saline in an oil layer are brought into an oil-water interface, the tower returning oil, the gas and the washing water are mixed intensively for multiple times, the salt and other corrosive media in the tower returning oil and the gas phase at the top of the tower are promoted to be transferred into the washing water, and finally, the oil-water high-efficiency separation is realized through the hydrophobic lipophilic film 702, so that the finally obtained corrosive media in the target.

Therefore, by using the method for preventing the salt corrosion of the stripping tower, provided by the embodiment of the invention, the returned tower oil and part of the corrosion medium in the gas phase at the top of the stripping tower can be efficiently removed on line, the influence of the corrosion medium on the stripping tower 1 is eliminated to the maximum extent, most of solid and suspended matters in the returned tower oil can be removed, and the possibility of mixed deposition of insoluble substances and ammonium salt and the adverse influence of the insoluble substances on long-period operation, heat transfer and mass transfer of the stripping tower, a heat exchanger and other equipment are reduced to the maximum extent. Therefore, the passive prevention and control of adding the corrosion inhibitor after salt deposition and upgrading the material of the equipment are changed into the active prevention and control before salt deposition, the problems of poor desalting effect, high cost or corrosion hidden danger and the like in the prior art are solved, and the safety, stability and long-period operation of the stripping tower can be effectively promoted.

In embodiments of the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The term "plurality" means two or more unless expressly limited otherwise.

The above description is only for facilitating the understanding of the technical solutions of the present invention by those skilled in the art, and is not intended to limit the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.