74- The feather leaf separator is used in the demisting design of the feed gas prior to entry into the tower for PSA pressure swing adsorption hydrogen recovery

Companies involved in the design and manufacture of PSA units, as well as owners operating PSA pressure swing adsorption systems, are aware that in addition to strict requirements regarding acidic gases, sulfur, oxygen, and other components, there are also strict requirements concerning the amount of liquid present in the feed gas, as well as any viscous substances it may contain. Therefore, an efficient gas-liquid separation demister with excellent anti-clogging performance must be installed on the PSA inlet pipeline.

In petrochemical plants, PSA units are often used for the separation and recovery of cracking hydrogen gas. As for the raw gas entering the tower, it contains a significant amount of C4+ components; in some plants, the liquid content in this raw gas can reach as much as 15%, and it also includes viscous degradation products as well as tiny particles resulting from the breakdown of catalysts. For such cracked hydrogen feed gas entering the PSA unit, what type of internal components should be used in an efficient gas-liquid demister to ensure the unit’s stable operation over extended periods of time? I will provide an introduction based on my actual project design experience.

Here is an example: 1. Operating temperature: 24.98 ℃； 2. Operating pressure: 5.50 MPa (A) ； 3. Gas phase composition: (v%) CO, 9.59; H2, 73.16; CO2, 1.56; N2, 2.72; AR, 1.45; CH4, 8.69; C2H4, 0.71; C2H6, 1.48; C3H6, 0.37; C3H8, 0.08; C4H8, 0.07; C4H10, 0.02; C5, 0.01; C6, 0.04; C7, 0.04; C8+ – remainder. 4. The seller shall take full account in the design of the unstable concentration of C4+ hydrocarbons in the feed gas, which can lead to liquid carryover in the feed gas; the maximum amount of liquid carryover should be considered as 15% of the total mass flow rate. 5. Inner component material: S30408

This post was last edited by luoli519 on 2023-9-26 at 16:17. Since the liquid content in the inlet gas reaches 15%, which is far above the 3–5% requirement specified by Shell’s DEP standards, it is mandatory to install a vaned separation and distribution assembly at the end of the inlet port on the inside of the gas-liquid separator. Additionally, it should be noted that for gas-liquid separators in vacuum conditions, due to the high velocity of the gas phase and its low density, Shell’s DEP standards also require the installation of a vane separation distribution assembly at the end of the inlet on the inside of the gas-liquid separator.

This post was last edited by luoli519 on 2023-9-26 at 16:17. Since the original gas contains high-carbon viscous substances as well as tiny particles of broken catalysts, traditional fiber-mesh or filter-element-type gas-liquid separation components are not suitable for use in the secondary precision separation unit. Instead, an inner component set with feather-shaped separation elements that offers excellent anti-clogging performance, or a multi-factor swirl parent/child separation inner component set should be used.

This post was last edited by luoli519 on 2023-9-26 at 16:17. Generally speaking, if the flow rate under operating conditions varies significantly, the operating pressure is at medium to low levels, and it is not desired that a large pressure difference be generated in the gas-liquid separator, then the vane separation internals technology is the preferred choice. Under the same operating conditions, the cost of the vane-separated internal components is lower than that of the cyclone parent/child-separated internal component set, due to various factors.

This post was last edited by luoli519 on 2023-9-26 at 16:18. When designing the vane separation internals, it is necessary to take into account the kinetic and momentum threshold requirements for air flow entering and leaving these internals, as specified by DEP, as design constraints. Otherwise, the operating gas velocity that separates the internal components via the vane channels cannot be maintained within the operating range of the efficient separation kinetic model; as a result, the liquid droplets and mist present in the raw gas cannot be effectively separated, or the separated droplets may be dispersed and carried away again by the high-speed gas flow, failing to ensure the separator’s efficient and quantitative separation performance.

This post was last edited by luoli519 on 2023-9-27 at 16:06. For the vane-separated internal component assembly, a liquid phase collection chamber, a liquid dropping system, and a liquid dropping tube sealing mechanism must be provided. Its purpose is to ensure that the liquid stream separated by the feather-leaf type separation internals is collected and then conveyed separately through a liquid dropping system to the low gas velocity liquid phase storage area, thereby preventing the separated droplets from coming into secondary contact with the upward-moving gas flow and being carried away, which would reduce the separation efficiency. Furthermore, it is also necessary to prevent the raw gas from taking a \"short circuit\" through the liquid dropping system and bypassing the vane separation internals, so that the liquid droplets in the raw gas can escape through the outlet without being removed by the vane separation internals.

This post was last edited by luoli519 on 2023-9-27 at 16:11. For the feather-leaf separated internal component assembly, a liquid phase collection chamber, a liquid dropping system, and a liquid dropping pipe sealing mechanism must be provided. Its purpose is to ensure that the liquid stream separated by the feather-leaf type separation internals is collected and then conveyed separately through a liquid dropping system to the low gas velocity liquid phase storage area, thereby preventing the separated droplets from coming into secondary contact with the upward-moving gas flow and being carried away, which would reduce the separation efficiency. Furthermore, it is also necessary to prevent the raw gas from taking a \"short circuit\" through the liquid dropping system and bypassing the vane separation internals, so that the liquid droplets in the raw gas can escape through the outlet without being removed by the vane separation internals.

This post was last edited by luoli519 on 2023-9-27 at 16:11. In the setup of the vane separation internal component, an air flow sealing guide mechanism must be installed to ensure that all raw gas passes through this component in order to have liquid droplets removed efficiently. Do not allow the original energy to escape via unsealed pathways in a \"short circuit\".