Carbon dioxide molecular sieve dehydration device for offshore platform

Abstract

The utility model discloses a carbon dioxide molecular sieve dehydration device for an offshore platform, which comprises a pre-filter and a first molecular sieve adsorption tower, the top end of the first molecular sieve adsorption tower is connected with the pre-filter through a pipe body, and the end part of the first molecular sieve adsorption tower is connected with a dry gas filter through a pipe body. The end part of the dry gas filter is connected with a regeneration gas electric heater through a pipe body, and the end part of the regeneration gas electric heater is connected with the bottom end of the second molecular sieve adsorption tower through a pipe body; when carbon dioxide is subjected to molecular sieve dehydration operation, the carbon dioxide is dried through the first molecular sieve adsorption tower, and compared with an existing molecular sieve dehydration device, the double-tower dehydration technological process of the first molecular sieve adsorption tower and the second molecular sieve adsorption tower is adopted, so that the occupied area is greatly reduced; the molecular sieve dehydration device can reduce the occupied area, and is more adaptive to an offshore production platform with limited space.

Description

Technical Field

[0001] The utility model relates to the technical field of molecular sieve dehydration devices, in particular to a carbon dioxide molecular sieve dehydration device for an offshore platform. Background Technique

[0002] As is well known, a molecular sieve, as a solid desiccant, relies on adsorption to dehydrate gases, that is, water molecules are adsorbed onto the solid surface. On the solid surface, the cohesive force that binds all solid molecules together is unbalanced, which results in a weak attraction to other molecules and a strong attraction to water, thus causing water molecules to adhere to the surface of the molecular sieve.

[0003] A molecular sieve is a synthetic zeolite, which is a porous network crystalline body of aluminum silicate hydroxide. It is a three-dimensional interconnected network structure of silicon and aluminum tetrahedrons. Each tetrahedron is composed of four oxygen atoms containing one silicon or aluminum atom. Each oxygen atom carries two negative charges, and each silicon atom carries four positive charges. This structure enables the network to be arranged covalently, causing each tetrahedron to expand uniformly in four directions. In this crystalline structure, half of the tetravalent silicon atoms can be replaced by trivalent aluminum atoms. Therefore, when producing molecular sieves, by adjusting the raw material ratio, silica containing various cations with different silicon-to-aluminum ion ratios and different crystalline structures can be produced. Trivalent aluminum makes the alumina tetrahedron negatively charged, and a cation needs to be added for balance. Therefore, the final network structure contains sodium, potassium, or calcium ions. These cations that balance the charges are exchangeable ions in the silica structure.

[0004] Ion exchangeability is a unique property of molecular sieves. These ions are at the openings of the cage structure of the molecular sieve. When sodium ions are exchanged with or replaced by larger or smaller cations, the openings of the cage structure become larger or smaller. Thus, we have a substance that can act as a molecular sieve or filter, so it is called a "molecular sieve".

[0005] For a patent application with publication number CN219502023U, publication date August 11, 2023, and title "An Enhanced Molecular Sieve Dehydration Device", this patent discloses an enhanced molecular sieve dehydration device, including a box body. Inside the box body, there is a ventilation chamber. Inside the ventilation chamber, there is a separation mechanism. The separation mechanism includes a motor. The output end of the motor is fixedly connected to a mounting frame. The side surface and bottom of the mounting frame are both provided with mesh frames. Inside the ventilation chamber and outside the separation mechanism, there is a ventilation mechanism. The ventilation mechanism includes a fan. The output end of the fan is fixedly connected to a shunt pipe. The outer side surface of the shunt pipe is fixedly connected with a plurality of through pipes. The side surface of the through pipe is provided with a plurality of inclined air outlet pipes. Through the above structure, the motor can be used to drive the molecular sieve in the mesh frame to rotate, and the water in the molecular sieve can be thrown out. At the same time, the air outlet pipes can be used to accelerate the rapid separation of water from the molecular sieve. With the dual dehydration effect, the dehydration efficiency of the molecular sieve can be accelerated, and the practicability of the device can be improved.

[0006] In the prior art, the molecular sieve dehydration device is large in volume and high in energy consumption. Moreover, there are a large number and various types of equipment on the offshore production platform, and the platform's planar and three-dimensional spaces are very limited, making the existing molecular sieve dehydration device not suitable for installation and operation in the narrow offshore space. Summary of the Utility Model

[0007] The purpose of the present utility model is to provide a carbon dioxide molecular sieve dehydration device for an offshore platform to solve the above problems in the prior art.

[0008] To achieve the above purpose, the present utility model provides the following technical solution: A carbon dioxide molecular sieve dehydration device for an offshore platform, including a pre-filter and a first molecular sieve adsorption tower. The top of the first molecular sieve adsorption tower is connected to the pre-filter through a pipe body. The end of the first molecular sieve adsorption tower is connected to a dry gas filter through a pipe body. The end of the dry gas filter is connected to a regeneration gas electric heater through a pipe body. It also includes a second molecular sieve adsorption tower. The end of the regeneration gas electric heater is connected to the bottom end of the second molecular sieve adsorption tower through a pipe body.

[0009] As described above, the top of the second molecular sieve adsorption tower is connected to a regeneration gas cooler through a pipe body.

[0010] As described above, the end of the regeneration gas cooler is connected to a regeneration gas separator through a pipe body.

[0011] As described above, the end of the regeneration gas separator is connected to a regeneration gas compressor through a pipe body.

[0012] As described above, a coalescing filter element is provided inside the pre-filter.

[0013] As described above, a quick-opening blind plate is installed on the side of the coalescing filter element.

[0014] As described above, a differential pressure gauge is installed on the pre-filter.

[0015] As described above, a gas distributor is provided at the inlet end of each of the first molecular sieve adsorption tower and the second molecular sieve adsorption tower.

[0016] As described above, the gas distributor includes a pipe fitting body and a cover plate. A pipe fitting body is provided at the inlet end of each of the first molecular sieve adsorption tower and the second molecular sieve adsorption tower, and a cover plate is provided on each of the two pipe fitting bodies.

[0017] As described above, a plurality of strip holes are evenly opened on the pipe fitting body, and a plurality of air inlet holes are evenly opened on the cover plate.

[0018] The beneficial effects of the present utility model are as follows: When performing molecular sieve dehydration operation on carbon dioxide, the carbon dioxide is dried by the first molecular sieve adsorption tower, and then the solid particles in the dried gas are removed by the dry gas filter. Then, the gas is heated by the regeneration gas electro-heater, so that the heated gas enters from the bottom end of the second molecular sieve adsorption tower, and the gas passes through the second molecular sieve adsorption tower from bottom to top, so that the water adsorbed on the molecular sieve is desorbed, and the activity of the molecular sieve is restored. The double-tower dehydration process flow of the first molecular sieve adsorption tower and the second molecular sieve adsorption tower is adopted. Compared with the existing molecular sieve dehydration device, the floor area is greatly reduced, so that the molecular sieve dehydration device can reduce the floor area of the device and is more suitable for the offshore production platform with limited space. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0020] Figure 1 It is a process flow diagram of an embodiment provided by the present utility model;

[0021] Figure 2 It is a front view of an embodiment provided by the present utility model;

[0022] Figure 3 It is a side view of an embodiment provided by the present utility model;

[0023] Figure 4 It is a top view of an embodiment provided by the present utility model;

[0024] Figure 5Equipment layout diagram of an embodiment provided by the present utility model;

[0025] Figure 6 Partial sectional structure schematic diagram of another embodiment provided by the present utility model.

[0026] Description of reference numerals:

[0027] 1. First molecular sieve adsorption tower; 2. Second molecular sieve adsorption tower; 3. Prefilter; 4. Dry gas filter; 5. Regenerated gas electric heater; 6. Quick-opening blind flange; 7. Regenerated gas cooler; 8. Regenerated gas separator; 9. Regenerated gas compressor; 10. Pipe fitting body; 11. Cover plate; 12. Strip-shaped hole; 13. Air inlet hole. Specific embodiments

[0028] In order to enable those skilled in the art to better understand the technical solutions of the present utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0029] As Figures 1 to 6 shown, in an embodiment provided by the present utility model, a carbon dioxide molecular sieve dehydration device for an offshore platform includes a prefilter 3 and a first molecular sieve adsorption tower 1. The top end of the first molecular sieve adsorption tower 1 is connected to the prefilter 3 through a pipe body. The end of the first molecular sieve adsorption tower 1 is connected to a dry gas filter 4 through a pipe body. The end of the dry gas filter 4 is connected to a regenerated gas electric heater 5 through a pipe body. It further includes a second molecular sieve adsorption tower 2. The end of the regenerated gas electric heater 5 is connected to the bottom end of the second molecular sieve adsorption tower 2 through a pipe body.

[0030] Specifically, the pre-filter 3 has a vertical cylindrical structure. Inside the pre-filter 3, there is a coalescing filter element (the coalescing filter element is made of various composite materials processed by a special process and has hydrophilic characteristics. It can not only filter out mechanical impurities in the medium, but also separate emulsified water from the medium through demulsification and coalescence, and coalesce it into larger water droplets to facilitate further purification of the medium); on the side of the coalescing filter element on the pre-filter 3, a quick-opening blind plate 6 is installed (the quick-opening blind plate 6 is used for the circular opening of a pressure pipeline or pressure vessel and is a mechanical device that can achieve quick opening or closing. For example, in this embodiment, it is installed on the side of the coalescing filter element on the pre-filter 3 to realize the replacement of the coalescing filter element); a differential pressure gauge is installed on the pre-filter 3, and the differential pressure gauge is used to detect the pressure difference of the filter element (that is, when there are more solid particles filtered by the filter element and the filtration pressure difference of the carbon dioxide gas passing through the coalescing filter element reaches the set value (such as: above 100 kPa), at this time, the quick-opening blind plate 6 should be opened to replace the filter element). The first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 are used to adsorb the saturated water carried in the carbon dioxide gas. The first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 are vertical steel pressure vessels. Inside the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, there are sequentially molecular sieves, grid plates, porcelain balls, and wire meshes (that is, there are grid plates inside the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, and molecular sieves are arranged on the grid plates. At the bottom of the grid plates inside the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, there is a wire mesh, and porcelain balls are arranged between the wire mesh and the grid plates). The molecular sieves are used to adsorb the moisture in the carbon dioxide gas, and the porcelain balls are used to support the upper molecular sieves and can evenly distribute the gas flow. There are various specifications of porcelain balls, and the diameter of the porcelain balls decreases sequentially from bottom to top, which can perform multi-stage shunting of the carbon dioxide gas. The dry gas filter 4 is used to remove the solid particles in the carbon dioxide gas, and the regeneration gas electric heater 5 is used to heat the carbon dioxide gas to remove the moisture in the carbon dioxide gas; the top of the second molecular sieve adsorption tower 2 is connected to a regeneration gas cooler 7 through a pipe body. The regeneration gas cooler 7 is used to cool the hot regeneration gas and cool the regeneration gas from a high temperature (such as: 244 °C) to a low temperature (such as: 40 °C); the end of the regeneration gas cooler 7 is connected to a regeneration gas separator 8 through a pipe body. The regeneration gas separator 8 is a vertical two-phase separator, mainly used to separate impurities such as free water carried in the wet regeneration gas; the end of the regeneration gas separator 8 is connected to a regeneration gas compressor 9 through a pipe body. The regeneration gas compressor 9 uses a reciprocating compressor unit to boost the regeneration gas from 3730 kPag to 4050 kPag and enter the pre-filter 3 for re-adsorbing and dehydrating;When molecular sieve dehydration treatment is required for carbon dioxide gas, the carbon dioxide gas passes through a pre-filter 3, so that the carbon dioxide gas passes through the coalescing filter element in the pre-filter 3, enabling the coalescing filter element to filter solids in the carbon dioxide gas and coalesce the droplets generated during the filtration of the carbon dioxide gas (the coalescing filter element can remove solid particles and droplets with a diameter greater than 5 μm in the carbon dioxide gas, and the intercepted solid particles and liquid are automatically discharged into the sewage system by the liquid level controller and control valve). The purified carbon dioxide gas after filtration flows out from the outlet of the pre-filter 3 and then flows into the first molecular sieve adsorption tower 1. The first molecular sieve adsorption tower 1 is used to dry the carbon dioxide gas, so that the dry gas after being dried by the first molecular sieve adsorption tower 1 enters the dry gas filter 4, and the dry gas filter 4 removes solid particulate matter in the carbon dioxide gas (an on-line water content analyzer is provided on the pipe body of the outlet pipe of the dry gas filter 4. When the water content reaches the high alarm set value, an alarm is issued to check the first molecular sieve adsorption tower 1 to ensure the stability of the first molecular sieve adsorption tower 1 in drying the carbon dioxide gas). Then it is transported to the regeneration gas electric heater 5, and the regeneration gas electric heater 5 is heated to a suitable temperature (such as: 260 °C). The carbon dioxide gas enters from the bottom of the second molecular sieve adsorption tower 2 and passes through the molecular sieve and porcelain balls from bottom to top. The second molecular sieve adsorption tower 2 is gradually heated to a suitable temperature (such as: 260 °C) by the regeneration gas electric heater 5 to desorb the water adsorbed on the molecular sieve and restore the activity of the molecular sieve (the regeneration heating process of the carbon dioxide gas lasts about 4.5 hours). After the regeneration of the carbon dioxide gas in the second molecular sieve adsorption tower 2 is completed, it enters the cold blow stage, that is, the regeneration gas flowing out from the top of the second molecular sieve adsorption tower 2 enters the regeneration gas cooler 7, so that the carbon dioxide gas is cooled to the cooling temperature (such as: 40 °C), most of the water in the carbon dioxide gas is condensed, enters the regeneration gas separator 8 to separate the condensate, and the gas is pressurized to a suitable pressure (such as: 4.05 MPag) by the regeneration gas compressor 9 and enters the feed header of the pre-filter 3 for re-adsorption dehydration. In this way, the regeneration gas of the carbon dioxide gas after molecular sieve dehydration can be obtained. The offshore production platform is rich in seawater resources. The high-temperature regeneration gas cooling adopts seawater heat exchange technology, which has higher heat exchange efficiency and lower energy consumption compared with air cooling or other cooling methods. The dual-tower dehydration process flow using the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 can greatly reduce the floor area compared with the existing molecular sieve dehydration device, enabling the molecular sieve dehydration device to reduce the floor area of the device and be more suitable for the offshore production platform with limited space; in the prior art, the molecular sieve dehydration device is large in volume and high in energy consumption, and there are many types of equipment on the offshore production platform with complex types, and the platform plane and three-dimensional space are very limited, making the existing molecular sieve dehydration device not suitable for installation and operation in the narrow space of the sea;In this embodiment, when dehydrating carbon dioxide with molecular sieves, the carbon dioxide is dried by the first molecular sieve adsorption tower 1, and then the dried gas is passed through the dry gas filter 4 to remove solid particles. Then, the gas is heated by the regeneration gas electro-heater 5, so that the heated gas enters from the bottom end of the second molecular sieve adsorption tower 2, and the gas passes through the second molecular sieve adsorption tower 2 from bottom to top, so that the water adsorbed on the molecular sieve is desorbed, and the activity of the molecular sieve is restored. The dual-tower dehydration process flow of the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 is adopted. Compared with the existing molecular sieve dehydration device, the floor area is greatly reduced, so that the molecular sieve dehydration device can reduce the floor area of the device and is more suitable for the offshore production platform with limited space.

[0031] In another embodiment provided by the present invention, a gas distributor is provided at the inlet end of each of the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 (that is, a gas distributor is provided at the top end of the first molecular sieve adsorption tower 1 and the bottom end of the second molecular sieve adsorption tower 2); the gas distributor includes a pipe fitting body 10 and a cover plate 11. A pipe fitting body 10 is provided at the inlet end of each of the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, and a cover plate 11 is provided on each of the two pipe fitting bodies 10; a plurality of strip-shaped holes 12 are uniformly opened on the pipe fitting body 10, and a plurality of air inlet holes 13 are uniformly opened on the cover plate 11.

[0032] Specifically, when the carbon dioxide gas enters the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, the carbon dioxide gas passes through the gas distributor, and the gas distributor evenly distributes the carbon dioxide gas, so that the carbon dioxide gas is more evenly distributed when it enters the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 (that is, the carbon dioxide gas is evenly distributed through the uniformly arranged air inlet holes 13 and strip-shaped holes 12, so that the carbon dioxide gas is more evenly distributed when it enters the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, improving the drying efficiency of the carbon dioxide gas); the uniformly arranged air inlet holes 13 and strip-shaped holes 12 can also prevent welding slag or other solid particles mixed in the inlet pipelines of the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2 from falling into the first molecular sieve adsorption tower 1 and the second molecular sieve adsorption tower 2, and perform secondary screening on the solid particles in the carbon dioxide gas. And during maintenance, the particulate matter filtered in the gas distributor can be cleaned to prevent the strip-shaped holes 12 and air inlet holes 13 in the gas distributor from being blocked.

[0033] Only some exemplary embodiments of the present utility model are described by way of illustration. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present utility model. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present utility model.

Claims

1. A carbon dioxide molecular sieve dehydration device for an offshore platform, comprising a pre-filter and a first molecular sieve adsorption tower, wherein the top of the first molecular sieve adsorption tower is connected to the pre-filter through a pipe body, the end of the first molecular sieve adsorption tower is connected to a dry gas filter through a pipe body, and the end of the dry gas filter is connected to a regeneration gas electric heater through a pipe body, characterized in that: It also includes a second molecular sieve adsorption tower, and the end of the regeneration gas electric heater is connected to the bottom end of the second molecular sieve adsorption tower through a pipe body.

2. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 1, characterized in that: The top of the second molecular sieve adsorption tower is connected to a regeneration gas cooler through a pipe body.

3. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 2, characterized in that: The end of the regeneration gas cooler is connected to the regeneration gas separator through a pipe body.

4. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 3, characterized in that: The end of the regeneration gas separator is connected to a regeneration gas compressor through a pipe body.

5. The carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 1, characterized in that: A coalescing filter element is arranged in the pre-filter.

6. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 5, characterized in that: A quick-opening blind plate is installed on the side of the coalescing filter element.

7. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 5, characterized in that: A differential pressure gauge is installed on the pre-filter.

8. The carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 1, characterized in that: A gas distributor is disposed at each of the gas inlet ends of the first molecular sieve adsorption tower and the second molecular sieve adsorption tower.

9. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 8, characterized in that: The gas distributor comprises a pipe body and a cover plate. The gas inlet ends of the first molecular sieve adsorption tower and the second molecular sieve adsorption tower are each provided with a pipe body, and each of the two pipe bodies is provided with a cover plate.

10. A carbon dioxide molecular sieve dehydration device for offshore platforms according to claim 9, characterized in that: The pipe body is evenly provided with a plurality of strip holes, and the cover plate is evenly provided with a plurality of air inlet holes.

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