Device and method for deeply desalting oil product

Abstract

The invention relates to an oil product deep desalting device and method, the device comprises at least one washing desalter, at least one oil-water separator and a magnetic transmission device, two washing desalting modules are arranged in the washing desalter, and each washing desalting module comprises a lipophilic coalescence filler block, a hydrophilic coalescence filler block, a magnetic medium and a slideway; the washing and desalting module is movably fixed on the slide way; the magnet transmission device can drive the magnetic medium to drive the washing and desalting module to vibrate and reciprocate along the slide way; the liquid outlet is connected with the oil-water separator. By utilizing the device, after oil and water are injected, the oil product to be treated and the water are dispersed through the coalescence filler, and the water can break through an oil-water interface through the movement of the washing and desalting module, so that the aim of deep contact mass transfer is fulfilled, the sufficient dissolution of salt is promoted, and the salt leaching efficiency is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of petrochemical engineering, and specifically relates to an apparatus for deep desalination of oil products and a method for desalination using the same. Background Art

[0002] The salt content in oil products directly affects the corrosion of subsequent equipment and has an adverse effect on the activity of catalysts, so desalination treatment is required. In recent years, with the development of secondary processing technologies and coal chemical technologies, more specific requirements have been put forward for the salt content in oil products after desalination. Generally, deep desalination is required, so that the salt content in the desalinated oil products is not more than 3 mg / L.

[0003] Currently, at home and abroad, the main methods for removing salts are electro - desalination methods or a combination of chemical and electro - desalination methods. For general light raw oil or oil product processing enterprises, it is easy to meet the index that the salt content in the desalinated oil products is not more than 3 mg / L by using electro - desalination methods. However, for those raw oils with high viscosity, high density and poor properties, the existing electro - desalination technologies are difficult to meet the standard. Even if a large amount of demulsifier is added, the salt content can only be reduced to 5 - 8 mg / L at most, resulting in serious salt deposition corrosion and product quality problems in subsequent devices. In addition, with the increase of heavy and inferior crude oils and the development of the coal - to - oil industry, the existing electro - desalination technologies are even more difficult to meet the desalination requirements. After a large number of experimental and industrial application effect comparison studies, it is found that a large part of the reason for the poor desalination effect of heavy and inferior oil products is the poor hydrophilicity and high viscosity of heavy and inferior oil products, which result in unsatisfactory mass transfer effect of oil - water mixing and contact, making it difficult for the injected water to mix deeply with the oil products to dissolve the salt in the water and remove it.

[0004] CN201911250606.X proposes a crude oil electro - desalination device and method, including a high - frequency / high - voltage pulsed AC power supply system, an electro - desalination device, a floating emulsified oil collector, an incoming oil pipeline, an oil pumping pipeline, a reinjection pipeline, a chemical addition pipeline, a heating device, and a compact tubular electric field demulsifier; the incoming oil pipeline is arranged at the upper part of the electro - desalination device, the floating emulsified oil collector is arranged in the emulsion layer and is connected to the bottom inlet of the compact tubular electric field demulsifier; the top outlet of the compact tubular electric field demulsifier is connected to the bottom of the electro - desalination device. This method uses traditional electro - desalination methods. And because there are many components in heavy and inferior oil products and there are great differences among various oil products, and many macromolecular compounds are difficult to be polarized, so the electro - desalination method has no general applicability for heavy and inferior oil products, and it has been proved in industrial applications that the desalination effect does not meet the standard.

[0005] CN201910660850.7 proposes an overweight extra-heavy oil treatment system and method. The treatment system includes a heat exchange device, a heating device, and a separation and electro-desalting device. The heat exchange device and the heating device are connected and transport the crude oil preliminarily heated by the heat exchange device to the heating device. The heating device heats the crude oil at a high temperature and transports it to the separation and electro-desalting device for separation and electro-desalting to obtain gas phase, water phase, and refined oil. The water phase and the refined oil are respectively transported to the heat exchange device through pipelines to preliminarily heat the crude oil. This method still uses the electro-desalting method, and for overweight extra-heavy oil raw materials, there are also problems such as many macromolecular compounds being difficult to be polarized, lack of universal applicability, and unqualified desalting effect.

[0006] CN200610105277.6 proposes a tar electric field purification technology. The method includes the following steps: ① Prepare the mixed oil. Mix coal tar and diluent oil (diesel or hydrogenated product oil) in a mass ratio of 1:(0 - 0.25) with a mixing pump, add a demulsifier, etc., and heat to 130 - 150 °C; ② Primary electro-desalting. After heating, the tar and the purified water are mixed and enter the electric field for dehydration; ③ Secondary electro-desalting. The tar and the purified water are mixed and enter the electric field for dehydration; ④ Tertiary electro-desalting. The tar and the purified water are mixed and enter the electric field for dehydration; ⑤ Sewage discharge. The sewage containing impurities removed from the coal tar is discharged from the primary electro-desalting. The above method still uses the electro-desalting and dehydration method to purify the coal tar, and there are problems such as incomplete separation of the oil and water phases, unsatisfactory desalting effect, and lack of universal applicability.

[0007] In summary, if we want to achieve deep desalting of heavy and inferior crude oil, the uniform and effective mixing of the oil product and water, and the comprehensive contact mass transfer between the oil product and water are important links in the desalting process. It is necessary to develop new processes and equipment to solve the problems existing in the traditional electro-desalting process of the existing technology, such as poor mixing effect in the oil-water washing and desalting process, serious entrainment between the oil and water phases, and unqualified salt content. Summary of the Invention

[0008] Aiming at the deficiencies of the existing technology, the present invention provides a device and method for deep desalting of oil products, which can effectively enhance the mixing of the oil product and water, increase the contact mass transfer efficiency between the two, so as to enable heavy and inferior oil products to achieve the effect of deep washing and desalting, and has the advantages of simple process flow, wide applicability, high desalting depth, etc.

[0009] The technical object of the present invention is achieved through the following technical solutions:

[0010] The technical object of the first aspect of the present invention is to provide a device for deep desalting of oil products. The device includes at least one washing and desalting device, at least one oil-water separator, and a magnetic drive device;

[0011] The washing and desalting device includes a tank body, in which two washing and desalting modules are arranged. The washing and desalting module I includes an oleophilic coalescing filler block, a hydrophilic coalescing filler block, a magnetic medium and a slideway. The oleophilic coalescing filler block and the hydrophilic coalescing filler block are arranged on both sides of the magnetic medium and fixed thereto. Slideways are arranged in the directions perpendicular to the middle magnetic medium on both sides of the washing and desalting module. The slideways are fixed to the tank body, and the washing and desalting module is movably fixed to the slideways. The washing and desalting module II has the same structure as the washing and desalting module I and is perpendicular to the washing and desalting module I in the layout direction. The magnet driving device is arranged outside the washing and desalting device and can drive the magnetic medium to drive the washing and desalting module to vibrate and reciprocate along the slideway. A liquid inlet is arranged on one side of the washing and desalting module I on the tank body, and a liquid outlet is arranged at the other end of the tank body and is connected to an oil-water separator.

[0012] Furthermore, the oleophilic coalescing filler block and the hydrophilic coalescing filler block are respectively made of fiber filaments with oleophilic functions and fiber filaments with hydrophilic functions, so that they have coalescing functions. Generally, the fiber filaments can be woven into corresponding block structures according to the shape of the washing and desalting device and placed in the washing and desalting device, or the fiber filaments can be woven into sheets and stacked in layers axially into block shapes and placed in the washing and desalting device. Preferably, when being woven, the fiber filaments are preferably woven into patterns with any one of concave-convex surface structures such as X-shaped, V-shaped, 8-shaped, Ω-shaped, water droplet-shaped or rhombus-shaped, which have better coalescing functions.

[0013] Furthermore, the fiber filaments with oleophilic functions are selected from at least one of polyester fiber filaments, nylon fiber filaments, polyurethane fiber filaments, polypropylene fiber filaments, polyacrylonitrile fiber filaments and polyvinyl chloride fiber filaments, or are selected from fiber filaments whose surfaces are oleophilically treated by physical or chemical methods.

[0014] Furthermore, the fiber filaments with hydrophilic functions are selected from high molecular polymers containing hydrophilic groups such as carboxyl (-COOH), amide (-CONH-), amino (-NH2-) or hydroxyl (-OH) in the main chain or side chain, and the more the number of hydrophilic groups contained, the better the hydrophilicity. Specifically, they are selected from at least one of polypropylene fibers, polyamide fibers and acrylic fibers, or are selected from fiber filaments whose materials are hydrophilically treated by physical or chemical methods.

[0015] Furthermore, the magnet drive is used to drive the magnetic medium to oscillate and move periodically or aperiodically along the slideway, so as to continuously update the contact interface between the oil and water phases, force the two-phase deep contact to occur, dissolve the salt wrapped inside the oil product in the water, and achieve the purpose of strengthening the mass transfer of the oil and water phases in contact; specifically, the magnet drive includes a magnetic medium, a fixed bushing, a crank connecting rod and a motor. One end of the fixed bushing is connected to the crank connecting rod, the other end is connected to the magnet, and the other end of the crank connecting rod is connected to the motor. The crank connecting rod rotates clockwise or counterclockwise driven by the motor, so as to drive the magnetic medium to move through the crank connecting rod, and the magnetic medium then drives the magnetic medium in the washing and desalting module to move through the magnetic force.

[0016] Furthermore, two magnet drives are provided, which respectively drive the magnetic media in the washing and desalting module I and the washing and desalting module II, and respectively control the movement of the two modules.

[0017] Furthermore, in principle, the magnetic medium in the magnet drive and the magnetic medium in the washing and desalting module can be any substance that exhibits magnetism under the action of a magnetic field. Ferromagnetic substances are preferred, and bar magnets are further preferred.

[0018] Those skilled in the art should understand that the magnetic drive can make the magnetic medium vibrate and move through magnetic force, so as to drive the entire washing and desalting module to reciprocate along the slideway.

[0019] Furthermore, the movement of the magnet drive driving the magnetic medium is vibration or reciprocating movement. Preferably, vibration and reciprocating movement occur simultaneously, which is more conducive to breaking through the mass transfer interface between the water phase and the oil phase and strengthening the washing and desalting function; by controlling the magnetic drive, the amplitude and frequency of its vibration and movement can be controlled, so as to strengthen the surface mass transfer between the raw materials and enhance the washing and desalting effect. In principle, the amplitude of the magnet drive is not quantified as long as vibration occurs. In practical applications, it is preferably 1-12 cm; the rotation frequency of the magnet drive is the number of times the turntable completes periodic changes per unit time, that is, the number of rotations per unit time, generally 1-50 revolutions per minute; the magnetic medium is generally a bar magnet, and the bar magnet is placed parallel or at any angle to the magnetic medium in the washing and desalting module, and the length can be equal or unequal to that of the bar magnet.

[0020] Furthermore, the length of the slideway is longer than the height of the washing and desalting module, so that the washing and desalting module can move axially. As a preference, the height of the washing and desalting module is 1 / 10-9 / 10 of the length of the slideway, preferably 3 / 10-7 / 10.

[0021] Generally speaking, if the floating space of the washing and desalting module is too small, it indicates that a large amount of coalescing packing is filled, and the function of forcing the material to migrate through vibration and floating is weakened, that is, the improvement degree of strengthening the washing and desalting effect cannot reach the best effect; while if the floating space of the washing and desalting module is too large, it indicates that the amount of coalescing packing filled is small. Although the function of forcing the material to migrate through vibration and floating is enhanced, due to the small amount of coalescing packing, the functions of dispersing and coalescing the material are weakened, and the improvement degree of strengthening the washing and desalting effect also cannot reach the best effect. Therefore, only when the height and slideway length of the washing and desalting module maintain a relatively appropriate ratio can the washing and desalting effect be guaranteed.

[0022] The oil-water separator has its inlet end connected to the liquid outlet of the washing and desalting device, and is used for separating the oil-water mixture after enhanced washing and desalting. The residence time is generally 10 min - 120 min; the oil-water separation can adopt any one or more of gravity sedimentation, hydrocyclone separation, baffle enhanced sedimentation, coalescing packing separation, etc. Preferably, the combination of coalescing packing and baffle is adopted inside, which can minimize the residence time and the entrainment of the oil and water phases with each other.

[0023] Furthermore, the device further includes a mixer, which is arranged at the front end of the washing and desalting device and is used for preliminarily mixing the oil product and water and then feeding them.

[0024] The technical object of the second aspect of the present invention is to provide a method for deeply desalting oil products by using the above device. The oil product to be treated and water are introduced into the washing and desalting module I. The magnetic drive device is started, and under the action of the magnetic field, the magnetic medium drives the washing and desalting module to vibrate and reciprocate along the slideway, so as to strengthen the contact mass transfer between the injected water and the oil product, and make the salt in the oil product fully dissolve in the water; then the material enters the washing and desalting module II, and under the action of the magnetic drive device, the washing and desalting module II vibrates and reciprocates in the direction perpendicular to the washing and desalting module I along the slideway, further strengthening the oil-water mass transfer and promoting the full dissolution of salt. After completion, the mixture is introduced into the oil-water separator from the liquid outlet on the side wall of the tank body to separate the oil and water and complete the desalting.

[0025] Those skilled in the art should understand that in the washing and desalting device of the present invention, the oil product to be treated and water can be mixed and introduced or separately introduced into the washing and desalting module, so that the water droplets contained in the raw oil coalesce, the oil phase is dispersed, and the water is dispersed on the surface of the coalescing packing, providing more ideal conditions and a larger contact surface for the contact mass transfer between the oil and water phases. When introducing them separately, preferably, the oil product to be treated is introduced into the hydrophilic coalescing packing block of the washing and desalting module I, and the water is introduced into the lipophilic coalescing packing block of the washing and desalting module I. Under the action of the coalescing packing, the oil product and water are continuously dispersed and coalesced, and at the same time, they vibrate and reciprocate axially, realizing a more sufficient and comprehensive mixing contact between the water and the oil product.

[0026] Further, after the oil product enters the tank body, in principle, the direction of setting the washing and desalting module can be used to make the material vibrate and move up and down first, then vibrate and move left and right, or vibrate and move left and right first, and then vibrate and move up and down. Only by ensuring that the oil product and water are mixed in two directions twice can the mass transfer of oil and water be greatly improved and the desalting effect be enhanced. Among them, it is preferably to make the oil product and water vibrate and move up and down first, and then vibrate and move left and right. This is because the oil product and water are separated at the initial feeding, and the two phases have a density difference. Using the up and down movement can overcome the influence of the density difference between the two phases and prevent the two phases from settling and separating. Then making it vibrate and move left and right can reduce or avoid phenomena such as uneven flow and channeling of the material, ensuring that the contact probability between oil and water is increased on the basis of no phase separation, thereby improving the salt washing efficiency.

[0027] Further, the oil product to be treated is any one or more of crude oil, distillate oil, waste oil, coal tar, gutter oil, anthracene oil, plastic oil, lubricating oil, and waste oil, etc.

[0028] Further, the injection amount of water is related to the salt content in the oil product to be treated, the requirements for desalting depth, the type of oil product, etc. Generally, the weight of the injected water accounts for 1wt%-30wt% of the weight of the oil product to be treated, preferably 5wt%-20wt%.

[0029] Further, the operating parameters in the washing and desalting device are as follows: the temperature is from normal temperature to 180°C, preferably 60-120°C; the pressure is 0.1-5.0MPa, preferably 0.3-2.0MPa.

[0030] In the above method, those skilled in the art should understand that for the oil-water mixture coming out of the washing and desalting module, after entering the oil-water separator, if the density of the oil phase is greater than that of the water phase, the water is separated from the upper part of the oil-water separator, and the oil is separated from the lower part; if the density of the oil phase is less than that of the water phase, the oil is separated from the upper part of the oil-water separator, and the water is separated from the lower part.

[0031] Compared with the prior art, the advantages of the present invention are as follows:

[0032] (1) The device and method of the present invention can greatly strengthen the contact mass transfer between heavy and inferior oil products and water, thereby more efficiently removing the salt in the oil product. First, the oil product to be treated and water are dispersed through coalescing fillers. Under the action of a magnetic field during the flowing process, through the vibration and reciprocating movement of the coalescing fillers, on the one hand, it can enable the water to break through the oil-water interface to achieve the purpose of deep contact mass transfer, and effectively prevent phenomena such as channeling and short-circuit flow; on the other hand, continuously break the material into droplets, form droplets of small droplets, continuously update the oil-water contact interface, and maintain a large oil-water contact surface, greatly improving the salt washing efficiency.

[0033] (2) In the preferred setting mode of the present invention, in the washing and desalting module I, the mixture of the oil product to be treated and water is dispersed by coalescing fillers. During the flowing process, under the action of the magnetic field, through the vibration and up-and-down movement of the coalescing fillers in the module, on the one hand, the influence of the density difference between the two phases can be overcome, thereby preventing the two-phase from settling and separating, creating conditions for deep desalting. On the other hand, the oil-water mixed material is continuously broken into small droplets, increasing the contact area between the oil and water phases, thereby improving the desalting efficiency. In the washing and desalting module II, through the vibration and left-and-right movement of the coalescing fillers in the module, on the one hand, the droplets are broken again, increasing the contact area between the oil and water phases and improving the desalting efficiency. On the other hand, in this way, the oil droplets and water droplets in the material are forced to maintain efficient contact, effectively preventing the problem of short-circuit flow.

[0034] (2) In the existing oil product desalting technology, almost all use electro-desalting technology. Due to the high viscosity and complex composition of heavy and inferior oil products, on the one hand, conventional oil-water mixing technologies are difficult to achieve deep contact, affecting the desalting effect, which is the main reason for the unqualified desalting effect. On the other hand, many macromolecular compounds in heavy and inferior oil products cannot be polarized in the electric field, so good oil-water separation effect cannot be achieved, which also affects the desalting effect. The present invention abandons the electro-desalting technology and develops a brand-new washing and desalting device and method suitable for heavy and inferior oils, which has the advantages of simple process, high desalting efficiency, and small water injection volume. Description of the Drawings

[0035] Figure 1 is a schematic diagram of the oil product deep desalting device in Embodiment 1;

[0036] Among them, 1. Oil product to be treated, 2. Water, 200. Oil-water mixer, 3. Oil-water mixture, 100. Washing and desalting device, 101. Washing and desalting module I, 102. Oilophilic coalescing filler block I, 103. Hydrophilic coalescing filler block I, 104. Magnetic medium I, 105. Slideway I, 106. Washing and desalting module II, 107. Oilophilic coalescing filler block II, 108. Hydrophilic coalescing filler block II, 109. Magnetic medium II, 110. Slideway II, 111. Liquid outlet, 4. Discharged oil-water mixture, 300. Oil-water separator, 301. Water phase (or oil phase) outlet, 302. Oil phase (or water phase) outlet, 400. Magnetic drive device I, 401. Bar magnet I, 402. Bush I, 403. Crank connecting rod I, 404. Motor, 500. Magnetic drive device II, 501. Bar magnet II, 502. Bush II, 503. Crank connecting rod II. Detailed Embodiments

[0037] The present invention will be described in detail below with reference to the description of the drawings and embodiments, but the present invention is not limited thereby.

[0038] Example 1

[0039] This example provides a device for deep desalination of oil products, as Figure 1 shown, which includes an oil-water mixer 200, a washing and desalting device 100, an oil-water separator 300, a magnetic drive device I 400 and a magnetic drive device II 500; the washing and desalting device includes a tank body, and two washing and desalting modules are arranged in the tank body. The washing and desalting module I 101 includes a lipophilic coalescing filler block I 102, a hydrophilic coalescing filler block I 103, a magnetic medium I 104 and a slideway I 105. The washing and desalting module II 106 includes a lipophilic coalescing filler block II 107, a hydrophilic coalescing filler block II 108, a magnetic medium II 109 and a slideway II 110. For the two washing and desalting modules, the lipophilic coalescing filler block and the hydrophilic coalescing filler block are both arranged on both sides of the magnetic medium and fixed thereto. Slideways are arranged in the direction perpendicular to the middle magnetic medium on both sides of the washing and desalting module, and the slideways are fixed to the tank body. The washing and desalting module is movably fixed on the slideways; the washing and desalting module II 106 is perpendicular to the washing and desalting module I 101 in the layout direction, that is, it is obtained by rotating the washing and desalting module I 101 counterclockwise by 90 degrees. The magnetic drive device I 400 and the magnetic drive device II 500 are arranged outside the washing and desalting device 200, and can respectively drive the magnetic media in the two washing and desalting modules to drive the washing and desalting modules to vibrate and reciprocate along the slideways; the magnetic drive device I 400 includes a bar magnet I 401, a bushing I 402, a crank connecting rod I 403 and a motor 404. The magnetic drive device II 500 includes a bar magnet II 501, a bushing II 502, and a crank connecting rod II 503. The two devices share a motor 404. For the two magnetic drive devices, one end of the bushing is connected to the crank connecting rod, the other end is connected to the bar magnet, and the other end of the crank connecting rod is connected to the motor. The crank connecting rod rotates clockwise or counterclockwise under the drive of the motor, so as to drive the bar magnet to move through the crank connecting rod, and the bar magnet drives the magnetic medium in the washing and desalting module to move through the magnetic field force; an oil-water mixer 200 is arranged at the front end of the washing and desalting device 100, which is connected to the washing and desalting module I 101. The other end of the washing and desalting device 100 is provided with a liquid outlet 111, which is connected to the oil-water separator 300. The oil-water separator 300 is provided with outlets, namely a water phase (or oil phase) outlet 301 and an oil phase (or water phase) outlet 302.

[0040] Among them, the lipophilic fiber filaments in the lipophilic coalescing filler block are made of two kinds of polyester fiber filaments and nylon fiber filaments, which are woven into a sheet-like V-shaped pattern and then stacked and bundled on the magnetic medium; the hydrophilic fiber filaments in the hydrophilic coalescing filler block are made of two kinds of polypropylene fibers and acrylic fibers, which are woven into a sheet-like V-shaped pattern and then stacked and bundled symmetrically with the lipophilic coalescing filler on the magnetic medium.

[0041] Example 2

[0042] This example provides a method for desalting oil products using the device of Example 1 as follows:

[0043] The oil product to be treated 1 and water 2 are preliminarily mixed through an oil-water mixer 200 to form an oil-water mixture 3, which is introduced into the washing and desalting module I 101 of the washing and desalting device 100. The magnetic drive device I 400 and the magnetic drive device II 500 are started. Under the action of the magnetic field, the magnetic medium I 104 drives the washing and desalting module I 101 to vibrate and move up and down along the slideway I 105, strengthening the mass transfer of water injection and the oil product, so that the salt in the oil product is fully dissolved in the water. Then the material enters the washing and desalting module II 106. The magnetic drive device II 500 is started. Under the action of the magnetic drive device, the washing and desalting module II 106 vibrates and moves left and right along the slideway II 110, further strengthening the oil-water mass transfer and promoting the full dissolution of salt. The completed oil-water mixture 4 of the discharged material is introduced into an oil-water separator 300 through the liquid outlet 111 on the side wall of the tank body. The oil and water are separated and discharged through the water phase (or oil phase) outlet 301 and the oil phase (or water phase) outlet 302 respectively to complete desalting.

[0044] Example 3

[0045] The oil product to be treated is heavy inferior raw oil, and its properties are shown in Table 1.

[0046] Table 1.

[0047]

[0048] The above inferior oil is deeply desalted using the devices and methods of Example 1 and Example 2:

[0049] Among them, the amplitude of the magnet drive device is 8 cm, and the rotation frequency is 5 revolutions per minute. The operating parameters of washing and desalting are as follows: the temperature of the washing and desalting device is 115 °C, the pressure is 1.2 MPa, and the mass of water injection accounts for 8.5% of the mass of the oil product to be treated.

[0050] The oil-water separator adopts the principle of gravity sedimentation. 55 layers of corrugated plates are filled inside the oil-water separator, and the residence time is 17 min; the results of the desalting effect after treatment are shown in Table 2.

[0051] Example 4

[0052] Different from Example 3, the amplitude of the magnet drive device is 12 cm, and the rotation frequency is 5 revolutions per minute. The operating parameters of washing and desalting are as follows: the temperature of the washing and desalting device is 120 °C, the pressure is 1.2 MPa, and the mass of water injection accounts for 7.8% of the mass of the oil product to be treated.

[0053] The oil-water separator adopts the principle of gravity sedimentation. There are 55 layers of corrugated plates filled inside the oil-water separator, and the residence time is 23 minutes. The results of the desalination effect after treatment are shown in Table 2.

[0054] Example 5

[0055] Different from Example 3, the operating parameters of washing desalination are as follows: the temperature of the washing desalination device is 118 °C, the pressure is 1.2 MPa, and the mass of the injected water accounts for 20% of the mass of the oil product to be treated.

[0056] The oil-water separator adopts the principle of gravity sedimentation. There are 55 layers of corrugated plates filled inside the oil-water separator, and the residence time is 30 minutes. The results of the desalination effect after treatment are shown in Table 2.

[0057] Comparative Example 1

[0058] The conventional three-stage electro-desalting + gravity sedimentation method is used to desalt the heavy raw oil in Table 1.

[0059] The three-stage electro-desalting equipment is an electro-desalting and dehydration device, and its structure is as follows: horizontal structure, internally divided into upper and lower spaces. The upper part is the electric field space, the lower part is the oil-water separation space, and there is a control section for the water and oil-water interface in the middle; there are several layers of horizontal electrode plates in the electric field space, and there are also hanging insulators, hanging plates, lead insulating rods, oil inlet nozzles, flow meters, etc. High-voltage electricity is transmitted to the electrode plates to form a high-voltage electric field, and a weak electric field is formed between the lower electrode plate at the bottom of the dehydrator and the water level. The gravity sedimentation equipment adopts a conventional baffle powder separator, with 55 layers of baffle plates inside, and the residence time is 30 minutes;

[0060] The operating conditions are as follows: operating temperature: 120 °C; operating pressure: 1.2 MPa; the total amount of injected water is 20% of the mass of the raw oil.

[0061] The desalting results are shown in Table 2.

[0062] Comparative Example 2

[0063] The four-stage electro-desalting + hydrocyclone separator method is used to desalt the heavy raw oil in Table 1.

[0064] The four-stage electro-desalting equipment is an electro-desalting and dehydration device, and its structure is the same as that of Comparative Example 1.

[0065] The operating conditions are as follows: operating temperature: 120 °C; operating pressure: 1.2 MPa; the total amount of injected water is 20% of the mass of the raw oil.

[0066] The desalting results are shown in Table 2.

[0067] Table 2.

[0068] Item Salt content after deep desalination, mg / L Example 3 2.77 Example 4 2.75 Example 5 2.72 Comparative Example 1 14.7 Comparative Example 2 13.6

[0069] As can be seen from the above experiments, compared with traditional electro-desalting and dehydration technologies, the device and method of the present invention have the advantages of simple process flow, high desalting efficiency, and small water injection volume. Especially for those heavy and inferior oils with high density, high viscosity, and high salt content, due to the large contact mass transfer resistance when the oil and water are mixed, the desalting depth far fails to meet the requirement of 3 mg / L. However, by using the device and method of the present invention, the contact mass transfer efficiency between the oil product and water can be effectively improved, enabling the heavy and inferior oil products to achieve the effect of deep washing and desalting.

Claims

1. An apparatus for deep desalination of oil products, characterized in that, The device includes at least one washing and desalting unit, at least one oil-water separator and a magnetic drive device; The washing and desalting unit includes a tank body, in which two washing and desalting modules are arranged. The washing and desalting module I includes an oleophilic coalescing filler block, a hydrophilic coalescing filler block, a magnetic medium and a slideway. The oleophilic coalescing filler block and the hydrophilic coalescing filler block are arranged on both sides of the magnetic medium and fixed thereto. Slideways are arranged on both sides of the washing and desalting module in a direction perpendicular to the middle magnetic medium, and the slideways are fixed to the tank body. The washing and desalting module is movably fixed on the slideways; The washing and desalting module II has the same structure as the washing and desalting module I and is perpendicular to the washing and desalting module I in the arrangement direction; The magnet drive device is arranged outside the washing and desalting unit and can drive the magnetic medium to drive the washing and desalting module to vibrate and move reciprocally along the slideway; A liquid inlet is arranged on one side of the washing and desalting module I on the tank body, and a liquid outlet is arranged at the other end of the tank body, which is connected to the oil-water separator.

2. The apparatus according to claim 1, characterized in that, The oleophilic coalescing filler block and the hydrophilic coalescing filler block are respectively made of fiber filaments with oleophilic functions and fiber filaments with hydrophilic functions woven into patterns with any one of the concave-convex structure surfaces in the shape of X, V, 8, Ω, water droplet or rhombus, so as to have a coalescing function.

3. The apparatus according to claim 2, characterized in that, The fiber filaments with oleophilic functions are selected from at least one of polyester fiber filaments, nylon fiber filaments, polyurethane fiber filaments, polypropylene fiber filaments, polyacrylonitrile fiber filaments and polyvinyl chloride fiber filaments, or are selected from fiber filaments whose surfaces are oleophilically treated by physical or chemical methods.

4. The apparatus according to claim 2, characterized in that, The fiber filaments with hydrophilic functions are selected from high molecular polymers whose main chains or side chains contain hydrophilic groups such as carboxyl groups, amide groups, amino groups or hydroxyl groups.

5. The apparatus according to claim 4, characterized in that, The fiber filaments with hydrophilic functions are selected from at least one of polypropylene fibers, polyamide fibers and acrylic fibers, or are selected from fiber filaments whose materials are hydrophilically treated by physical or chemical methods.

6. The apparatus according to claim 1, characterized in that, The magnet drive device includes a magnetic medium, a fixed shaft sleeve, a crank connecting rod and a motor. One end of the fixed shaft sleeve is connected to the crank connecting rod, and the other end is connected to the magnet. The other end of the crank connecting rod is connected to the motor. The crank connecting rod rotates clockwise or counterclockwise under the drive of the motor, so as to drive the magnetic medium to move through the crank connecting rod, and the magnetic medium then drives the magnetic medium in the washing and desalting module to move through the magnetic field force.

7. The apparatus according to claim 6, characterized in that, Two magnet drive devices are arranged, which respectively drive the magnetic media in the washing and desalting module I and the washing and desalting module II, and respectively control the movement of the two modules.

8. The apparatus according to claim 6, characterized in that, The magnetic medium in the magnet drive device and the magnetic medium in the washing and desalting module are any substance that exhibits magnetism under the action of a magnetic field.

9. The apparatus according to claim 6, characterized in that, The amplitude of the magnet drive device is 1-12 cm; The rotation frequency of the magnet drive device is 1-50 revolutions per minute.

10. The apparatus according to claim 1, characterized in that, The length of the slideway is longer than the height of the washing and desalting module, so that the washing and desalting module can move axially. The height of the washing and desalting module is 1 / 10-9 / 10 of the length of the slideway.

11. The apparatus according to claim 1, characterized in that, The inlet end of the oil-water separator is connected to the liquid outlet of the washing and desalting device; the oil-water separation adopts any one or more of gravity sedimentation, hydrocyclone separation, baffle enhanced sedimentation, and coalescing packing separation.

12. The apparatus according to claim 1, characterized in that, The device further includes a mixer, which is arranged at the front end of the washing and desalting device.

13. A method for deep desalination of oil products using the apparatus according to claim 1, comprising: The oil product to be treated and water are introduced into the washing and desalting module I. The magnetic drive device is started. Under the action of the magnetic field, the magnetic medium drives the washing and desalting module to vibrate and reciprocate along the slideway, so as to strengthen the contact mass transfer between the injected water and the oil product, and make the salt in the oil product fully dissolve in the water; then the material enters the washing and desalting module II. Under the action of the magnetic drive device, the washing and desalting module II vibrates and reciprocates in a direction perpendicular to the washing and desalting module I along the slideway, further strengthening the oil-water mass transfer and promoting the full dissolution of salt. After completion, the mixture is introduced into the oil-water separator from the liquid outlet on the side wall of the tank body, and the oil and water are separated to complete desalting.

14. The method according to claim 13, characterized in that, After the oil product enters the tank body, by setting the direction of the washing and desalting module, the material first vibrates and moves up and down, then vibrates and moves left and right, or first vibrates and moves left and right, and then vibrates and moves up and down.

15. The method according to claim 13, characterized in that, The oil product to be treated is any one or more of crude oil, distillate oil, waste oil, coal tar, gutter oil, anthracene oil, plastic oil, lubricating oil, and waste oil, etc.

16. The method according to claim 13, characterized in that, The weight of the injected water accounts for 1wt%-30wt% of the weight of the oil product to be treated.

17. The method according to claim 13, characterized in that, The operating parameters in the washing and desalting device are as follows: the temperature is normal temperature - 180°C, and the pressure is 0.1 - 5.0MPa.

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