93- Feather leaf separation inlet separation assembly and precision separation internals for the LNG project’s MDEA absorber outlet separator and MRC buffer tank
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This post was last edited by luoli519 on 2023-9-27 at 14:47. In the new LNG projects built in recent years both domestically and internationally, project owners, design firms, and process package suppliers have paid more attention and invested greater effort in MDEA absorption tower systems and MRC compression systems; in particular, they pay close attention to the material consumption and operating costs of MDEA absorption tower systems, as well as the investment required for selecting MRC compression systems and their electricity consumption and operating costs. This is directly related to the operational costs of the entire project as well as its economic viability. The vane separation assembly and vane separator bring about technological improvements by being used in the gas-phase outlet separators of MDEA absorption towers as well as in the buffer separators of the MRC compression system; they are crucial for reducing the material consumption and operating costs of the MDEA absorption tower systems, as well as the investment costs associated with the selection of equipment and the electrical energy consumption in the MRC compression system. Please discuss this in light of the operating conditions and technical usage of the MDEA absorption tower system and MRC compression system separation equipment in your respective LNG plants.
In previous LNG plants, although the MDEA absorption units could handle large volumes of gas, specialized gas-liquid separation equipment was rarely installed at the gas phase outlet section at the top of the absorption tower. In actual operation, due to the high gas flow rate exiting the tower, a large amount of MDEA solution droplets are entrained, resulting in high MDEA consumption. Severe liquid accumulation occurs in the pipelines downstream of the purified gas, especially in the lower sections, which leads to poor gas flow and unstable operating pressure drops.
Later, in response to the owner’s feedback, domestic process package suppliers and design institutes installed wire mesh demister internals on the inside of the vapor outlet pipe at the top of the MDEA absorber in new projects. The liquid carryover in the overhead gas of the MDEA absorber has been improved to a certain extent. However, the wire mesh demister has limited operational flexibility, high operating pressure drop, and weak corrosion resistance, although the liquid carryover in the exhaust gas from the MDEA absorber has been improved to some extent.
This post was last edited by luoli519 on 2023-9-26 at 15:14. Foreign process packages are equipped with specialized vane separators on the gas-phase outlet pipeline of the MDEA absorber. As a result, domestic process package suppliers also followed suit, adopting vane-type separation internals to replace the original mesh-type demisting internals. The feather leaf separator offers significant improvements over screen separators in terms of quantitative separation efficiency, operational flexibility, operating pressure drop, and operational maintenance costs.
This post was last edited by luoli519 on 2023-9-26 at 15:14. The vane separator’s precision separation components ensure efficient operation when the liquid content in the airflow does not exceed 7%. Other fiber mesh-type and filter element-type gas-liquid separation internals have an even lower tolerance to the amount of liquid carried in the gas stream. To prevent crime and mitigate fluctuations in the airflow velocity within the MDEA tower as well as in the inflow and outflow rates of the MDEA solution, it is usually necessary to install a vane separation assembly at the inlet pipe of the vane separator, in order to reduce the amount of liquid contained in the airflow to below 7%, thus ensuring that the precision separation components of the vane separator operate efficiently.
This post was last edited by luoli519 on 2023-9-26 at 15:15. The vane separation assembly manufactured based on the design results of the system platform calculated using precise dynamics separation technology is capable of pre-separating air streams with up to 75% liquid content and evenly distributing their kinetic energy and momentum, thereby ensuring efficient operation of the subsequent vane separation internal components. Dehydrating an airflow with a liquid content as high as 75% is essentially a degassing process in the liquid phase. It can be seen that the vaned separation assembly manufactured based on the design results of the system platform calculated using precise dynamics separation technology possesses excellent pre-separation and pre-allocation capabilities in terms of operational flexibility.
Here, we take as an example the gas-liquid separator for the gas outlet pipeline of the MDEA absorber in an LNG project, which was developed by our company, as an integrator of LNG process packages in Shandong, using our precise kinetic separation technology design platform.
This post was last edited by luoli519 on 2019-12-23 at 15:42. The operating conditions for the efficient gas-liquid separator required to be installed in the gas outlet pipeline of the MDEA absorber for this project are shown in the chart below:
This post was last edited by luoli519 on 2023-9-26 at 15:15. The results regarding the efficient gas-liquid separation in the gas outlet pipeline of the MDEA absorber, achieved through the use of precise dynamic gas-liquid separation technology in our system design for the aforementioned operating conditions, are as follows: 1. Separator type: Vaned demister (vertical)； 2. Inlet separation assembly: Feather blade separation assembly ； 3. Separation efficiency: 4N level separation to remove liquid droplets and bubbles of 9.92 microns and larger in size ； 4. Total pressure drop during operation (from inlet pipe to outlet pipe): 0.88 kPa ； 5. Operational flexibility: 15%-130%.
For the inlet buffer separation tank of the MRC mixed refrigerant compressor, since no separate starting tank for the mixed refrigerant and no emergency shutdown tank are provided in the process package, the first-stage inlet separation tank of the MRC mixed refrigerant compressor is used as the starting tank, while the second-stage inlet separation tank is used as the emergency shutdown tank. This requires the inlet separation tank of the MRC compressor to have functions such as large-volume liquid storage, efficient gas-liquid separation despite a high liquid content, and fluid buffering, and it is designed in a horizontal configuration to increase the storage space for the liquid phase.
This post was last edited by luoli519 on 2023-9-26 at 15:16. As is well known, the inlet airflow of MRC compressors contains a large amount of liquid mixed refrigerant; under such conditions, it is necessary to use vane separation assemblies to remove this high proportion of liquid from the inlet airflow in advance, as well as to evenly distribute the kinetic energy and momentum of the inlet fluid.