Multi-medium coalescence filter oil product dewatering device

Abstract

This invention relates to a multi-media controlled oil dehydration device, comprising a shell with a feed inlet, a water outlet, and an oil outlet. The dehydration device includes a feed distributor, a particulate media assembly, and a fiber media assembly, sequentially installed in the lower, middle, and upper parts of the shell. The feed distributor is connected to the feed inlet pipeline. The lower part of the particulate media assembly has a support, and the upper part has an intercepting net. The lower part of the fiber media assembly has a support, and the intercepting net is installed below the support. The particulate media assembly communicates with the fiber media assembly through the intercepting net. This invention, by combining the particulate media assembly and the fiber media assembly, effectively removes water and impurities carried in the oil, optimizes the oil-water separation process, improves the dehydration effect, and achieves an emulsion water separation efficiency greater than 80%.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical production equipment technology, and relates to a device for dehydrating oil products in petrochemical enterprises, specifically a multi-media coalescence filtration oil dehydration device. Technical Background

[0002] Oil refineries use steam stripping towers to remove trace amounts of hydrogen sulfide and dry gas from oil products. However, steam stripping often results in diesel emulsification with water, making the oil cloudy and opaque, unsuitable for direct sale. Therefore, the stripped oil needs to be left to settle in storage tanks for an extended period, followed by bottom-cutting to remove the emulsified water. Because the water droplets in emulsified diesel are small, the prolonged gravity settling process occupies a significant amount of settling tank space. When the capacity of these tanks is limited, selling unseparated diesel (still opaque or even containing water) lowers the grade of the finished product and impacts the company's economic profits. This is a prominent problem that urgently needs to be addressed in current oil production. To solve this, diesel dehydration facilities have been added after stripping to ensure the diesel meets the required water content.

[0003] Commonly used diesel fuel dehydration technologies include vacuum dehydration, electro-dehydration, and coalescing dehydration. Vacuum dehydration offers high separation precision and stability, but it is costly, difficult to operate and maintain, and has a small throughput, so it is generally not used. Electro-dehydration offers high separation precision and large throughput, but its operating conditions are narrow, dehydration results fluctuate greatly, equipment costs are high, and safety is poor, so it is rarely used in diesel fuel dehydration. Coalescing dehydration offers high separation precision, but its stability is poor, its lifespan is short, and it requires frequent filter replacements.

[0004] Existing methods struggle to reduce the water content of diesel fuel to the required quality levels, especially in winter, where water precipitation causes the product to appear cloudy, failing to meet customer requirements. Furthermore, these methods suffer from complex processes and high operating costs. To solve the diesel fuel dehydration problem, there is an urgent need to develop a diesel fuel dehydration device that is simple in process, stable in operation, and highly efficient. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-media coalescing filtration oil dehydration device, which effectively removes water carried in oil by combining a combination of hydrophilic and hydrophobic particulate media and a combination of hydrophilic and hydrophobic fiber media, optimizes the oil dehydration and purification process, and improves the oil dehydration effect.

[0006] The technical solution of this invention is: a multi-media coalescing filtration oil dehydration device, comprising a shell, with an inlet, a water outlet, and an oil outlet on the shell. The dehydration device includes a feed distributor, a particulate media assembly, and a fiber media assembly, which are sequentially installed in the lower, middle, and upper parts of the shell. The feed distributor is connected to the inlet pipeline. The lower part of the particulate media assembly has a support, and the upper part has an intercepting net. The lower part of the fiber media assembly has a support, and the intercepting net is installed below the support. The particulate media assembly communicates with the fiber media assembly through the intercepting net. The particulate media assembly consists of one or more hydrophilic particles, or a combination of hydrophilic and oleophilic particles forming a particle layer, with a separation space above the particle layer.

[0007] The particulate media assembly comprises high-surface-energy and low-surface-energy materials for adsorbing water and oil droplets. Hydrophilic and oleophilic particles are mixed and randomly stacked in bulk to form a particle layer, with a filling ratio of 1:1 to 5:1. The filling height of the particle layer is 1 to 5 times the diameter of the shell. The particle diameter of both the oleophilic and hydrophilic particles in the particle layer is 0.05 to 0.5 mm. The oleophilic particles are made of PTFE, and the hydrophilic particles are made of silica.

[0008] The fiber media assembly has a ring-shaped columnar structure. The inner and outer layers of this structure are enclosed by perforated steel plates, with the dewatering fiber media sandwiched between them. The fiber media is woven from high-surface-energy metal fibers and low-surface-energy non-metal fibers, and is used to separate emulsified water dissolved in oil. The ratio of high-surface-energy metal fibers to low-surface-energy non-metal fibers is 1:1 to 5:1. The high-surface-energy metal fibers are made of stainless steel, and the low-surface-energy non-metal fibers are made of PTFE. The number of weaving intersections between the high-surface-energy metal fibers and the low-surface-energy non-metal fibers is 10,000 to 15,000 per cubic decimeter. The ratio of the longitudinal thickness of each layer of fiber material to the shell diameter is 0.15 to 0.45, and the porosity of the fiber media assembly is 0.1 to 0.25. The droplet size range of the dewatering material in the particulate media assembly is 30-200 micrometers, while that in the fiber media assembly is 5-50 micrometers.

[0009] The feed distributor is either a ring-shaped distributor or a cross-shaped distributor, with upward-facing openings. The dewatering unit is equipped with a backwash steam line and / or a backwash nitrogen line, which are connected to the feed inlet line.

[0010] This invention comprises an oil dehydration device and a multi-media assembly for controlling the size of water droplets in the oil. The multi-media assembly includes at least two materials with different surface energies and combinations of at least two material structures, used to control the size of water droplets flowing through the assembly. The materials with different surface energies are high-surface-energy materials and low-surface-energy materials, used to adsorb water and oil droplets, and to separate emulsified water from the oil. The material structures are either granular or fibrous, used to provide adsorption surfaces and channels for controlling droplet movement.

[0011] The multi-media coalescing filtration oil dehydration device of the present invention is equipped with a feed distributor, a particulate media assembly, and a fiber media assembly. Oil containing trace amounts of water passes through the particulate media assembly bed at a uniform flow rate after being rectified by the feed distributor, removing mechanical impurities and free water entrained in the diesel oil. Then, it passes through the fiber media assembly to remove emulsified water. The dehydrated and purified diesel oil exits the device from the oil outlet at the top of the device. The separated water phase falls into the bottom of the device in the form of water droplets under the action of gravity and is discharged from the water outlet.

[0012] This invention combines a coalescing media composed of hydrophilic and lipophilic particles with a fibrous media composed of hydrophilic high-surface-energy metal fibers and lipophilic low-surface-energy non-metallic fibers. Water-containing oil first passes through a particle layer, where the hydrophilic and hydrophobic particles filter, adsorb, and coalesce to remove water impurities. Then, the fibrous media separates the oil droplets from the water droplets by capturing the emulsion's tiny water droplets with the hydrophilic high-surface-energy metal fibers and capturing the oil droplets with the lipophilic low-surface-energy non-metallic fibers, thus removing the emulsion water. This invention optimizes the oil-water separation process, improves dehydration efficiency, and achieves an emulsion water separation efficiency of over 80%. This invention features a compact structure, high efficiency, long operating cycle, and low operating costs, resulting in significant economic benefits.

[0013] The advantages of this invention are: ① It can simultaneously and deeply remove suspended solids and emulsified water from oil products, with a short process, high removal efficiency, and the ability to automate the process. ② It features completely closed-loop treatment, no pollution, low energy consumption, and long operating cycles. ③ It can also be used to treat wastewater containing fine oil droplets, achieving oil droplet aggregation and separation. It has broad application prospects in multiple fields, including oily wastewater treatment from offshore platforms and FPSOs, removal of oil droplets from lubricants and cleaning agents during metal processing, and treatment of municipal wastewater treatment plants and industrial wastewater containing grease. Attached Figure Description

[0014] Figure 1 A schematic diagram of the structure of the multi-media coalescence filtration and oil dehydration device for the invention;

[0015] Figure 2 A schematic diagram illustrating the principle of water droplet capture using a particulate media assembly;

[0016] Figure 3 A schematic diagram illustrating the principle of water droplet capture using a fiber-based media assembly;

[0017] Wherein: 1—shell, 2—feed inlet, 3—water outlet, 4—feed distributor, 5—particulate media assembly support, 6—particulate media assembly, 7—interception net, 8—fiber media assembly support, 9—fiber media assembly, 10—oil outlet, 11—free large water droplets, 12—oleophilic particles, 13—hydrophilic particles, 14—low surface energy non-metallic fiber, 15—water droplets, 16—high surface energy metallic fiber, 17—oil droplets, 18—large water droplets, 19—detached large water droplets, 20—large oil droplets, 21—cross node, 22—emulsified small water droplets. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the embodiments and accompanying drawings. The scope of protection of the present invention is not limited to the embodiments, and any modifications made by those skilled in the art within the scope defined by the claims also fall within the scope of protection of the present invention.

[0019] The multi-media coalescence filtration oil dehydration device of the present invention, such as Figure 1 As shown, the system includes a housing 1, with an inlet 2, a water outlet 3, an oil outlet 10, a backwash steam pipeline, and a backwash nitrogen pipeline. The inlet is installed at the bottom of the housing, the water outlet at the bottom, and the oil outlet 10 at the top. Inside the housing are a feed distributor 4, a particulate media assembly 6, and a fiber media assembly 9, which are sequentially installed at the top, middle, and bottom of the housing. The feed distributor is connected to the inlet 2 pipeline, and the backwash steam and backwash nitrogen pipelines are also connected to the inlet pipeline. The particulate media assembly 6 has a particulate media assembly support 5 at its lower part and an intercepting net 7 at its upper part. The fiber media assembly 6 has a fiber media assembly support 8 at its lower part, and the intercepting net 7 is installed at the lower part of the fiber media assembly support 8. The fiber media assembly support has a ring structure, and the particulate media assembly 6 is connected to the fiber media assembly 9 through the intercepting net 7. The particulate media assembly 6 is composed of a randomly packed and mixed granular layer of hydrophilic and oleophilic particles, with a separation space above the granular layer. The diameter of the oleophilic and hydrophilic particles in the particulate media assembly is 0.05–0.5 mm. The oleophilic particles are made of PTFE, and the hydrophilic particles are made of silica. The filling ratio of hydrophilic to oleophilic particles is 1:1 to 5:1, and the filling height of the granular layer is 1 to 5 times the diameter of the shell 1.

[0020] The fiber media assembly 9 is a ring-shaped columnar structure, surrounded by perforated steel plates on both the inner and outer sides, with a dehydrated fiber media layer between the inner and outer steel plates. The upper part of the ring-shaped columnar structure has a cover plate, and the lower part is a ring-shaped fiber media assembly support 8. The central hole of the fiber media assembly support serves as a connection channel between the particle media assembly 6 and the fiber media assembly 9. An intercepting net 7 is located at the connection channel, intercepting particles from entering the upper fiber media assembly. Figure 3 As shown, the dewatering fiber media assembly is woven from high surface energy metal fibers 16 and low surface energy non-metal fibers 14, with a ratio of high surface energy metal fibers to low surface energy non-metal fibers of 1:1 to 5:1. The high surface energy metal fibers are made of stainless steel, and the low surface energy non-metal fibers are made of PTFE. The number of weaving intersections 21 of the high surface energy metal fibers and low surface energy non-metal fibers is 10,000 to 15,000 per cubic decimeter. The ratio of the longitudinal thickness of each layer of fiber material in the dewatering fiber media assembly to the shell diameter is 0.15 to 0.45, and the porosity of the fiber media assembly is 0.1 to 0.25. The feed distributor 4 is an annular distributor with upward-facing openings.

[0021] The principle of water droplet capture by the particulate media composite particle layer is as follows: Figure 2 As shown, water-containing oil enters the shell of the dehydration unit through the feed distributor 4. It rises through a particle layer composed of hydrophilic particles 13 and oleophilic particles 12. The particles adsorb small water droplets in the diesel fuel through adsorption and aggregation, gradually forming large free water droplets 11. The separated water droplets fall into the shell under gravity and are discharged from the water outlet. The oil phase and emulsified small water droplets 22 continue to rise. The principle of water droplet capture by the fiber media assembly is as follows... Figure 3 As shown, oil and water droplets are separated by the action of high surface energy metal fibers 16 capturing emulsified micro water droplets and low surface energy non-metallic fibers capturing oil droplets. Low surface energy non-metallic fibers 14 capture water droplets 15, which coalesce into larger water droplets 18, and finally, the larger water droplets detach from the oleophilic low surface energy non-metallic fibers. High surface energy metal fibers 16 capture oil droplets 17, which aggregate into larger oil droplets 20, and the larger oil droplets detach from the hydrophilic high surface energy metal fibers. The purified oil exits the device from the oil outlet at the top of the shell, while the separated aqueous phase falls as droplets under gravity and exits from the water outlet. This invention utilizes the surface properties and structures of different materials to deeply demulsify and separate emulsified micro water droplets in the oil, achieving high separation efficiency. The multi-media coalescence filtration oil dehydration device has a compact structure, and the separated oil is clear and of good quality. After six months of operation, the device is backwashed with steam or nitrogen to remove dirt from the surface of particles and fibers, restoring their dehydration activity.

[0022] Example 1

[0023] Diesel fuel carrying trace amounts of water underwent oil-water separation. The diesel fuel had a high emulsion water content (total water content fluctuating between 800 and 1500 mg / L) and poor appearance. The multi-media coalescing filtration oil dehydration device of this invention was used for diesel dehydration. In the particulate media assembly 6, the diameter of the oleophilic and hydrophilic particles in the particulate layer was 0.3 mm, the filling ratio of hydrophilic to oleophilic particles was 1:1, and the filling height of the particulate layer was 1.5 times the diameter of the shell 1. In the fiber media assembly 9, the ratio of hydrophilic metal fibers to oleophilic non-metal fibers was 1:1. The ratio of the longitudinal thickness of each fiber material layer in the dehydration fiber filter layer to the shell diameter was 0.25, and the porosity of the fiber media assembly was 0.15. Analysis data of the diesel fuel at the inlet and outlet of the device are shown in Table 1.

[0024] Table 1. Diesel fuel dehydration analysis data

[0025]

[0026]

[0027] Analysis results show that the water content in the diesel fuel at the feed inlet is 800-1500 mg / L, and the water content in the dehydrated diesel fuel is reduced to 300-420 mg / L, and the diesel fuel has a clear appearance.

[0028] The multi-media coalescing filter oil dehydration device of this invention can be used to dehydrate deeply emulsified diesel oil. The treated diesel oil can achieve a clear and bright appearance and a significant reduction in water content.

[0029] Example 2

[0030] Dehydration Treatment of Recycled Sludge Oil from Coking Units. Recycled sludge oil from coking units suffers from high impurity content and severe water contamination, causing fluctuations in coking furnace temperature and pressure, affecting the normal and safe operation of the coking unit. Therefore, impurity removal and dehydration treatment are necessary. This invention employs a multi-media coalescing filter oil dehydration device to purify recycled sludge oil from coking units, removing mechanical impurities, free water, and emulsified water. The dehydration device uses a 0.25mm particle size for both oleophilic and hydrophilic particles in its granular layer, with a 1:3 ratio of hydrophilic to oleophilic particles and a filling height 2.5 times the shell diameter. The ratio of hydrophilic metal fibers to oleophilic non-metal fibers is 1:1. The ratio of the longitudinal thickness of each fiber material layer in the dehydration fiber filter layer to the shell diameter is 0.30, and the porosity of the fiber media assembly is 0.20. The dehydration process is compared with traditional techniques such as gravity sedimentation, cyclone centrifugal separation, and coalescing filter cartridges. The implementation details of each technique are shown in Table 2.

[0031] Table 2. Data on the purification and dehydration treatment of waste oil from coking plants.

[0032]

[0033] Analysis results show that, in terms of separation accuracy (mechanical impurities and water removal effect), operating pressure drop, packing replacement, and backwashing cycle, the implementation effect of this invention is significantly better than conventional technology, and it has lower operating costs and energy consumption.

[0034] Example 3

[0035] In the coal tar hydrogenation process, coal tar feedstock undergoes impurity removal and dehydration pretreatment. Coal tar is characterized by high impurity content, small particle size, and a density close to that of water. Existing coal tar pretreatment methods employ mechanical centrifugation (2500-3500 rpm), three-stage basket filtration (filtration accuracies of 100 microns, 50 microns, and 25 microns respectively), a single-stage coalescing filter for dehydration, and a single-stage flash evaporation for dehydration. These existing technologies suffer from high energy consumption, frequent filter switching and cleaning (labor-intensive manual cleaning, 1-2 times / day), and short filter life (high consumable costs and equipment operating costs). This invention utilizes a multi-media coalescing filter oil dehydration device that combines existing technologies for dehydration and purification. The multi-media coalescing filter oil dehydration device is installed after the mechanical centrifuge and before flash evaporation, eliminating the need for multi-stage basket filtration and coalescing filter dehydration processes.

[0036] After the implementation of the solution, the pretreatment purification and dehydration process of coal tar was shortened, the dehydration effect was obvious, the labor intensity of operators was reduced, the operating cost and energy consumption were reduced, and the continuous operation cycle was extended.

Claims

1. A multi-media controlled oil dehydration device, comprising a shell (1), wherein the shell is provided with a feed inlet (2), a water outlet (3), and an oil outlet (10); characterized in that: The dehydration device is provided with a feed distributor (4), a particulate media assembly (6), and a fiber media assembly (9). The feed distributor, particulate media assembly, and fiber media assembly are installed in the lower, middle, and upper parts of the housing in sequence. The feed distributor is connected to the feed inlet pipeline. The lower part of the particulate media assembly is provided with a particulate media assembly support (5), and the upper part is provided with an intercepting net (7). The lower part of the fiber media assembly is provided with a fiber media assembly support (8). The intercepting net is installed at the lower part of the fiber media assembly support. The particulate media assembly is connected to the fiber media assembly through the intercepting net. The particulate media assembly (6) is composed of one or more hydrophilic particles (13), or a particulate layer composed of hydrophilic particles and oleophilic particles (12). The upper part of the particulate layer is a separation space.

2. The multi-media controlled product dehydration device according to claim 1, characterized in that: The hydrophilic particles (13) and oleophilic particles (12) are mixed and bulk-stacking to form a particulate medium assembly. The filling ratio of the hydrophilic particles to the oleophilic particles is 1:1 to 5:1, and the filling height of the particulate medium assembly is 1 to 5 times the diameter of the shell (1).

3. The multi-media controlled oil dehydration device according to claim 1, characterized in that: The diameter of the oleophilic particles (12) and hydrophilic particles (13) is 0.05-0.5 mm; the oleophilic particles are made of PTFE and the hydrophilic particles are made of silicon dioxide.

4. The multi-media controlled product dehydration device according to claim 1, characterized in that: The fiber medium assembly (9) is a ring-shaped columnar structure. The inner and outer layers of the ring-shaped columnar structure are surrounded by perforated steel plates, and the fiber medium is in the middle of the inner and outer steel plates. The fiber medium is woven from high surface energy metal fibers (16) and low surface energy non-metal fibers (14), and the ratio of high surface energy metal fibers to low surface energy non-metal fibers is 1:1 to 5:

1.

5. The multi-media controlled oil dehydration device according to claim 4, characterized in that: The high surface energy metal fiber (16) is made of stainless steel, and the low surface energy non-metallic fiber (14) is made of PTFE.

6. The multi-media controlled oil dehydration device according to claim 4, characterized in that: The number of weaving cross nodes (21) of the high surface energy metal fibers and low surface energy non-metal fibers is 10,000 to 15,000 per cubic decimeter.

7. The multi-media controlled oil dehydration device according to claim 4, characterized in that: The ratio of the longitudinal thickness of each fiber material layer of the high surface energy fiber filter layer to the shell diameter is 0.15 to 0.45, and the porosity of the fiber media assembly is 0.1 to 0.

25.

8. The multi-media controlled oil dehydration device according to claim 1, characterized in that: The droplet size range adjustable by the particulate media assembly is 30-200 micrometers, and the droplet size range adjustable by the fiber media assembly is 5-50 micrometers.

Images