Sea water purification and precipitation separator for LNG storage tank pressure test

Abstract

Provided is a seawater purification and sedimentation separator for LNG storage tank pressure testing, comprising a tank body, a flow divider, a water collecting structure, a sludge sedimentation zone and a sludge homogenizing device, the tank body forms a cavity, the tank wall of the tank body is provided with a water inlet pipe and a water outlet pipe; the flow divider is arranged in the cavity; the water collecting structure is arranged above the separator; the sludge sedimentation zone is located at the bottom of the cavity and comprises an inclined surface and a sludge hopper, the sludge hopper is used for containing separated sludge; the sludge homogenizing device comprises a transmission device and a sludge scraping plate, the sludge scraping plate is opposite to the inclined surface, and the transmission device is used for driving the sludge scraping plate to move so as to scrape off the sludge on the inclined surface. The seawater purification and sedimentation separator can realize efficient purification and treatment of seawater.

Description

Technical Field

[0001] This utility model relates to the field of liquefied natural gas processing, specifically to the field of seawater purification sedimentation separators for LNG storage tank pressure testing. Background Technology

[0002] Before LNG storage tanks are put into use, a hydrostatic test is required to ensure their safe operation. However, due to the large size of LNG storage tanks and the large volume of seawater used for the test, as well as the high amount of suspended solids such as silt in the seawater, the seawater purification process requires a separator capable of efficient sedimentation to provide qualified water for the hydrostatic test of the LNG storage tanks. Utility Model Content

[0003] One objective of this invention is to provide a seawater purification sedimentation separator for LNG storage tank pressure testing, so as to achieve efficient purification of seawater.

[0004] The seawater purification sedimentation separator for achieving the above objectives includes a tank, a distributor, a water collection structure, a sludge sedimentation zone, and a sludge homogenization device. The tank forms a cavity, and the tank wall is provided with an inlet pipe and an outlet pipe. The distributor is disposed within the cavity. The water collection structure is disposed above the separator. The sludge sedimentation zone is located at the bottom of the cavity and includes an inclined surface and a sludge hopper, which is used to contain the separated sludge. The sludge homogenization device includes a transmission device and a scraper. The scraper faces the inclined surface, and the transmission device is used to drive the scraper to move, thereby scraping away the sludge located on the inclined surface.

[0005] In one or more embodiments, the sludge settling zone includes a plurality of inclined plate support cones distributed in a radial direction, the inclined plate support cones forming the inclined surface, and the sludge hopper located radially inside the inclined plate support cones.

[0006] In one or more embodiments, the separator further includes a sludge pipe in communication with the sludge hopper.

[0007] In one or more embodiments, the sludge homogenization device further includes a main shaft, a support, a tie rod assembly, and a scraper arm. The main shaft passes through the separator, with one end connected to a transmission device located outside the tank body, and the other end inserted into the support located at the bottom of the tank body, so as to achieve rotational movement under the drive of the transmission device. The scraper arm is provided with a scraper plate at its end, and the scraper arm is connected to the main shaft through the tie rod assembly.

[0008] In one or more embodiments, the separator further includes a mud-water separator located circumferentially between the vortex separator and the tank wall, the mud-water separator including a separation screen.

[0009] In one or more embodiments, the water collection structure includes a water collection branch channel and a water collection main channel located at the radially outer end of the water collection branch channel, the surface of the water collection branch channel having a downward slope in the radial direction, and the water collection main channel being connected to the water outlet pipe.

[0010] In one or more embodiments, the main water collection channel is located above the inlet pipe.

[0011] In one or more embodiments, the water collection branch canal includes a water collection branch canal diversion weir, the water collection main canal includes a water collection main canal diversion weir, and the water collection branch canal diversion weir and the water collection main canal diversion weir are at the same horizontal height.

[0012] In one or more embodiments, the tank wall is provided with a magnesium strip.

[0013] In one or more embodiments, the diverter is a vortex diverter located in the middle of the cavity, the side of the vortex diverter is connected to the water inlet pipe, and the bottom of the vortex diverter is connected to the cavity.

[0014] The aforementioned sedimentation separator effectively separates seawater mixtures containing suspended solids by combining a diverter, a water collection structure, a sludge sedimentation zone, and a sludge equalization device inside the tank. This allows purified water to be collected through the water collection structure, while the sediment is effectively discharged after being treated by the sludge sedimentation zone and the sludge equalization device. Attached Figure Description

[0015] The above and other features, properties and advantages of this utility model will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0016] Figure 1 This is a top view of a seawater purification sedimentation separator;

[0017] Figure 2 This is a top view of the sludge homogenization device;

[0018] Figure 3 yes Figure 1 Cross-sectional view along the AA direction;

[0019] Figure 4 yes Figure 1 Cross-sectional view along the BB direction;

[0020] Figure 5 This is a top view of a mud-water separator;

[0021] Figure 6 This is a top view of the sludge settling area. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0023] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be used as a limitation on the scope of protection of this utility model.

[0024] Seawater contains a high concentration of suspended solids, including but not limited to silt, algae, organic debris, and microorganisms. The concentration of suspended solids varies with the sea area and season. To efficiently remove suspended solids from seawater and prevent large amounts of suspended solids from accumulating at the bottom of LNG storage tanks, seawater purification must be prepared before the experiment.

[0025] Reference Figures 1 to 6 As shown, the seawater purification sedimentation separator is a storage tank made of steel plates, mainly consisting of a tank body 10, a vortex diverter 2, a sludge sedimentation zone 8, and a sludge homogenization device 9. These structures can all be pre-cut from steel plates of appropriate dimensions and welded on-site. The outer wall of the storage tank is fixed to the bottom plate by triangular reinforcing ribs.

[0026] The tank body 10 forms a cavity 11, and the tank wall 12 of the tank body 10 is provided with an inlet pipe 1 and an outlet pipe 7.

[0027] Seawater is transported to the treatment unit through pipelines and pumps. Before entering the high-efficiency sedimentation separator, the seawater can first undergo coagulation and flocculation reactions by adding coagulants and flocculants, which aggregates fine particles into larger flocs, making it easier for the sedimentation separator to remove suspended solids and colloidal particles more effectively, and ensuring stable effluent quality.

[0028] Seawater, after pretreatment via coagulation or flocculation, or a combination of both, or directly enters the inlet pipe 1 of the sedimentation separator. Inlet pipe 1 is directly connected to vortex distributor 2. Vortex distributor 2 is fixed to the working bridge 100 outside the tank 10 via bracket 21. Figure 3 As shown.

[0029] In some embodiments, the vortex diverter 2 can be made of the same material as the high-efficiency sedimentation separator, with a hollow circular cross-section, located in the center of the high-efficiency sedimentation separator, with a height of 2200-2400 mm and a top distance of 300-350 mm from the top of the high-efficiency sedimentation separator. The vortex diverter 2 can reduce the impact of the inlet water on the water in the tank and reduce turbulence. This allows the water flow to diffuse from the center to the surrounding areas, forming a more ideal laminar flow state, which helps particle sedimentation, provides a more stable sedimentation environment for suspended particles, and prevents the inlet water from flowing directly to the outlet, ensuring that the water has sufficient residence time in the tank. This allows the inlet water to be evenly distributed across the entire cross-section of the high-efficiency sedimentation separator, avoiding short-circuiting and excessively high local flow velocities, and improving the sedimentation effect.

[0030] Seawater enters the sludge-water separation zone 3 after passing through the vortex diverter 2. In the sludge-water separation zone 3, the heavier flocs settle rapidly, while the seawater continues to enter the upper oblique flow clarification zone 4. Simultaneously, the remaining smaller flocs settle in this area, and the settled flocs slide down the sludge separator 41 under gravity to the sludge settling inclined plate 81. The sludge-water separator 41 is supported by the sludge-water separator support 42.

[0031] In one specific embodiment, the sludge separator 41 includes a separation screen for separation. The separation screen is made of PP or FRP material, has a length of 1000mm, an installation angle of 60°, and is evenly distributed along the space between the vortex distributor 2 and the wall 12 of the high-efficiency sedimentation separator tank. Its bottom end is 200-250mm higher than the bottom of the vortex distributor 2. One end of the main support 421 of the sludge separator 41 is welded to the tank wall, and the other end is welded to the vortex distributor 2; the two ends of the auxiliary support 422 of the sludge separator are respectively welded to the adjacent main support 421, such as... Figure 5 As shown in the top view.

[0032] Water flows upwards along the mud-water separator 41 to the water collection structure, which includes water collection branch channels 5 and a main water collection channel 6. Multiple water collection branch channels 5 are evenly distributed around the tank circumference, such as 6 to 8 channels. One end of each water collection branch channel 5 is welded to the vortex diverter 2, and the other end connects to the main water collection channel 6. In one specific embodiment, the top of each water collection branch channel 5 is 400 to 450 mm from the top of the high-efficiency sedimentation separator. A water collection branch channel diversion weir 51 is installed on the upper part of each water collection branch channel 5.

[0033] The main collection channel 6 is arranged around the tank, and its outer wall is shared with the tank wall 12 of the new high-efficiency sedimentation separator. A diversion weir 61 is installed on the upper part of the main collection channel 6. The diversion weirs 51 of the branch collection channels and the diversion weirs 61 of the main collection channel are adjusted to the same horizontal height to maintain a stable water level in the tank, ensure sedimentation effect, ensure uniform water flow distribution, prevent short-circuiting, and improve sedimentation efficiency.

[0034] Considering the gravity flow of water, the branch collection canals 5, from the vortex diverter 2 to the main collection canal 6, and the main collection canal 6, arranged around the tank, all slope in the direction of water flow, that is, the surface of the branch collection canals slopes radially ( Figure 3 The water flows outwards at a downward slope (left and right directions). The slope is 1% to 3%. The bottom of the water collection branch channel 5 at the inlet pipe is flush with the bottom of the main water collection channel 6. Finally, the purified water flows out through the outlet pipe 7 for use.

[0035] like Figure 4 and Figure 6 As shown, the sludge settling zone 8 includes a sludge settling inclined plate 81, an inclined plate supporting cone plate, a sludge hopper 83, and a sludge pipe 84. Figure 3 Four inclined plate support cones 82 are shown, arranged radially inwards in sequence. One end of each inclined plate support cone 82 is welded to the bottom of the tank, and the other end is welded to the sludge settling inclined plate 81 above. The surfaces of the multiple inclined plate support cones 82 form an inclined surface 80. The number and position of these cones from the wall of the high-efficiency sedimentation separator to the center are determined by the specific diameter of the high-efficiency sedimentation separator. The sludge hopper 83 is located radially inside the inclined plate support cones 82, and the inner side of the inclined plate support cones 82 rapidly slopes to form the inclined sidewall of the sludge hopper 83. Sludge is deposited on the sludge settling inclined plate 81 and is scraped into the sludge hopper 83 at the center of the tank bottom by the sludge homogenization device 9.

[0036] Continue to refer to Figure 4 As shown, the sludge homogenization device 9 includes a transmission device 91, a main shaft 92, a tie rod assembly 93, a scraper arm 94, a support 95, and a scraper blade 96. The transmission device 91 is fixed on the working bridge 100. The main shaft 92 is vertically installed along the center of the tank, passes through the vortex diverter 2, and is connected at one end to the transmission device 91 and at the other end to the support 95. The support 95 is welded to the bottom of the tank to ensure that the main shaft 92 is always vertical. The main shaft 92 is connected to the scraper arm 94. In the tie rod assembly 93, one end of the first tie rod 931 is connected to the main shaft 92, and the other end is connected to the scraper arm 94. The two ends of the second tie rod 932 are respectively connected to the adjacent scraper arms 94. The scraper blade 96 is installed on the scraper arm 94, and the scraper blade 96 faces the inclined surface 80. In a specific embodiment, the distance between the scraper blade 96 and the inclined surface 80 is approximately 30-50 mm.

[0037] like Figure 2 and Figure 4 As shown, the sludge homogenization device 9 rotates along direction C under the drive of the transmission device 91, and scrapes the sludge into the sludge hopper 83 through the scraper 96, and discharges it for disposal through the sludge pipe connected to the sludge hopper 83.

[0038] Meanwhile, to reduce the corrosion of the high-efficiency sedimentation separator in seawater by high concentrations of chloride ions and increase its service life, magnesium strips can be installed on the tank wall. A sacrificial anode cathodic protection method can be used, making the metal surface the cathode. Through the preferential corrosion of the sacrificial anode, electrons are provided to the tank metal, preventing it from losing electrons and being oxidized. This avoids or reduces damage to the high-efficiency sedimentation separator due to electrochemical corrosion during seawater purification. Alternatively, internal corrosion protection can be directly applied.

[0039] The aforementioned high-efficiency sedimentation separator for LNG storage tank pressure testing effectively reduces suspended solids in seawater, providing a large quantity of qualified water for the LNG storage tank pressure test. The equipment is simple, efficient, space-saving, has high processing capacity, is easy to assemble and disassemble, is modular, and reusable.

[0040] Table 1 shows a comparison of the influent and effluent water quality, demonstrating that the seawater purification sedimentation separator has a superior sedimentation treatment effect. SS (mg / L) is a unit of measurement for the concentration of suspended solids in water, representing the number of milligrams of suspended solids per liter of water sample.

[0041] Table 1. Main water quality indicators of seawater influent and effluent (unit: mg / L)

[0042] Water ingress 2600 7.06 Out of water 79 7.06

[0043] It should be noted that the use of terms such as "first" and "second" to define components in the above description is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning, do not represent primary or secondary, and therefore should not be construed as limiting the scope of protection of this application.

[0044] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0045] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0046] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible variations and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A seawater purification sedimentation separator for LNG storage tank pressure testing, characterized in that, include: The tank body includes a cavity and a tank wall, and the tank wall is provided with an inlet pipe and an outlet pipe; A flow divider is disposed within the cavity; A water collection structure is located above the separator; The sludge settling zone, located at the bottom of the cavity, includes an inclined surface and a sludge hopper, which is used to hold the separated sludge. as well as A sludge homogenization device includes a transmission device and a scraper blade, the scraper blade facing the inclined surface, and the transmission device driving the scraper blade to scrape away the sludge located on the inclined surface.

2. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 1, characterized in that, The sludge settling zone includes multiple inclined plate support cones distributed radially, with the inclined plate support cones forming the inclined surface on their surfaces, and the sludge hopper located radially inside the inclined plate support cones.

3. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 2, characterized in that, The separator also includes a sludge pipe connected to the sludge hopper.

4. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 1, characterized in that, The sludge homogenization device also includes a main shaft, a support, a tie rod assembly, and a scraper arm. The main shaft passes through the separator, with one end connected to a transmission device located outside the tank, and the other end inserted into the support located at the bottom of the tank, so as to achieve rotational movement under the drive of the transmission device. The scraper arm is provided with a scraper plate at its end, and the scraper arm is connected to the main shaft through the tie rod assembly.

5. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 1, characterized in that, The seawater purification sedimentation separator also includes a mud-water separator, which is circumferentially located between the distributor and the tank wall. The mud-water separator includes a separation screen.

6. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 1, characterized in that, The water collection structure includes water collection branch channels and a main water collection channel located at the radially outer end of the water collection branch channels. The surface of the water collection branch channels has a downward slope in the radial direction. The main water collection channel is connected to the outlet pipe.

7. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 6, characterized in that, The main water collection channel is located above the water inlet pipe.

8. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 6, characterized in that, The water collection branch canal includes a branch canal diversion weir, and the water collection main canal includes a main canal diversion weir. The branch canal diversion weir and the main canal diversion weir are at the same horizontal height.

9. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 1, characterized in that, The tank wall is lined with magnesium strips.

10. The seawater purification sedimentation separator for LNG storage tank pressure testing as described in claim 1, characterized in that, The diverter is a vortex diverter located in the middle of the cavity. The side of the vortex diverter is connected to the water inlet pipe, and the bottom of the vortex diverter is connected to the cavity.

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