202-Design of a steam liquid removal, desalination, and scaling removal separator for the secondary steam heat pump compressor in the natron project’s multi-effect evaporator

It includes an evaporator, a heat pump compressor, and a secondary steam vapor-liquid-solid separator for saline-alkaline mother liquor, and belongs to the category of precise kinetic separation technologies. As the saline and alkaline droplets carried by the steam pass through the separation internals, their shape and size become elongated and thinner ； After passing through the internal components, the equivalent dimensional size of the droplets and bubbles increases back to their original size as the fluid velocity suddenly decreases and the surface tension causes them to expand again. The operation mechanism of gas-liquid separation is completely different from that of simple separation techniques that use screens, filter elements, and other types of \"porous structures\" to block and trap particles; in such techniques, the equivalent size of solid particles in the fluid remains essentially unchanged during the filtration process, as in gas-solid and liquid-solid filtration applications. Therefore, vapor-liquid separation equipment must be accurately designed and properly configured by specialized companies in kinetic separation technology, using authoritative and precise kinetic separation technology calculation and configuration design platforms, in order to deliver efficient and reliable separation performance in actual operation. A vapor-liquid separator that relies solely on certain separation internals for its appearance, without being accurately designed and properly configured using a reliable and precise dynamic vapor-liquid separation system platform, will inevitably have deficiencies in its actual operational performance as well as safety hazards!

The last edit to this post was made by luoli519 on 2022-3-22 at 11:03. For the operating conditions of multi-effect evaporators handling saline-alkaline mother liquor, the physical and chemical parameters such as temperature, pressure, liquid phase composition, gas phase composition, gas phase eccentricity factor, gas phase density, gas phase viscosity, the composition of saline-alkaline droplets and mist carried by the gas flow, as well as the density and viscosity of these droplets and mist, and their surface tension, vary for each stage and each effect of the evaporator. Therefore, the required configurations for the separation systems also differ accordingly. This requires a professional company specializing in dynamic separation technologies to, based on the macroscopic process parameters provided by the project owner and the design institute, utilize its advanced dynamic separation technology as well as the calculation and configuration systems and database platforms to make necessary improvements, so as to develop a reliable technical solution. The owner and the design institute can only provide the macroscopic process parameters corresponding to the process equipment; they lack an authoritative and accurate dynamic separation technology calculation and configuration design system platform to obtain, in a thorough and precise manner, the physicochemical property data for each phase required for the dynamic separation solutions mentioned above.

This post was last edited by luoli519 on 2022-3-22 at 11:13. The data showing the operating conditions of the crystallization chamber in the four-effect evaporator, as provided by the property owner and the design institute, are shown in the figure below:

Here is the attached diagram showing the operating data for the crystallization chamber of the five-effect evaporator, provided by the property owner and the design institute:

This post was last edited by luoli519 on 2022-3-22 at 11:58. By comparing the operating data of the crystallization chambers in four-effect and five-effect evaporators, it can be seen that: 1. Since basic operating parameters such as operating temperature, operating pressure, liquid phase composition, amount of secondary steam, steam density, and steam viscosity change, the corresponding values for properties of liquid droplets and foam, such as density, viscosity, and surface tension, will inevitably also change. However, the owner and the design institute are unable to provide the physicochemical property data corresponding to the actual operating conditions of liquid droplets and foam; such data are essential for the computational design of vapor-liquid-solid separators. It is necessary for specialized companies in dynamic separation technology to supplement and complete these data using their authoritative and precise dynamic separation technology-based calculation and configuration design system platforms, so that a complete set of parameters can be input into the system platform to develop an accurate separation solution. Non-specialized separation technology companies do not take into account the changes in droplet and foam density, viscosity, and surface tension under different operating conditions; instead, they perform calculations using fixed values. The owner and the design institute must verify these changes in the key physicochemical property data that affect separation efficiency from their separation process calculations, in order to determine the reliability of the separation process calculations provided by the supplier. For some suppliers, the calculation documents related to the separation process of their separators do not take into account the density, viscosity, and surface tension of liquid droplets and foam when calculating the separation efficiency; such documents can be dismissed outright. The supplier may tell the owner and the design institute that the separation process calculations are one thing, while the actual operation of the separator is another. Owners and design institutes should not think this way! Admittedly, the actual operating conditions of the separator may deviate to some extent from those calculated in the separation process design documents ； However, if the computational design of a separator cannot provide reliable written documentation as a basis, how can one expect it to happen to be reliable in actual operation? ? A detailed technical calculation document for precise and reliable dynamic separation techniques serves as the target; if the target cannot be identified, it is impossible to expect to hit it.

This post was last edited by luoli519 on 2022-3-22 at 12:01. 2. Both the owner and the design institute have the same separation requirements for the separators in the crystallization chambers of the four-effect and five-effect evaporators; both require that “droplets with a size of 10 microns or larger be removed at a separation efficiency of 99.9%”. Such technical requirements are unprofessional and clearly problematic. It can be inferred that such technical requirements were likely provided to the owners and design firms by non-specialized separation technology companies. For companies that specialize in precision dynamic separation technologies, \"removing droplets with a size of 10 microns or larger at a separation efficiency of 99.9%\" is only possible in \"medium-low pressure, medium pressure, and high-pressure operating conditions\"” ； In vacuum or even medium-to-high vacuum conditions, most of the dispersed liquid droplets and mist in the airflow are smaller than 10 micrometers. In a \"vacuum operating condition,\" the separator is designed and manufactured according to the requirements for \"medium-low pressure, medium pressure, and high pressure conditions,\" with the aim of removing liquid droplets of 10 microns or larger at a separation efficiency of 99.9%. As a result, the vast majority of salt- and alkali-containing liquid droplets in the vacuum stream that are smaller than 10 microns cannot be separated and escape, ending up in the heat pump compressor and causing scaling on its impellers and rotating shafts. In some enterprises, accidents have occurred due to scaling on the impeller shaft of Siemens heat pump compressors caused by secondary steam from the evaporator, which led to imbalance issues and subsequent tearing during high-speed rotation. Everyone needs to pay sufficient attention!

The last edit to this post was made by luoli519 on 2022-3-22 at 16:09. 3. (Gas) Vapor-liquid separators: As discussed earlier, the liquid droplets and mist carried in the gas stream undergo size changes as they pass through the separation elements, which makes it easier for them to pass through; therefore, the same separation principles applicable to solids with constant sizes cannot be used. Instead, a “grid” filtering method is typically employed. Therefore, the vapor-liquid separator is a device based on kinetic separation technology; it is essential that a professional company specializing in kinetic separation technology develop an accurate technical solution using its advanced kinetic separation techniques and configuration design system platforms – this is a prerequisite. Without the prerequisite of advanced and precise dynamic separation technologies as well as a configuration design system platform, even the use of gold-plated components cannot achieve efficient separation performance. Many property owners and staff from design firms have asked how to determine whether a supplier possesses authoritative and accurate dynamics separation technology as well as a configuration design system platform. By asking the supplier to provide certification documents regarding its ownership of such technologies and platforms issued by authorized service providers, it is possible to find out the answer. The attached document is the certification issued by a certain technology service provider for its advanced and accurate dynamics separation technology as well as its configuration design system platform; it can be used as a reference:

This post was last edited by luoli519 on 2024-4-8 at 16:39. 4. According to the separation process requirements provided by the owner and the design institute, the supplier is required to submit documents such as calculations for the separation process, tables and charts, separation efficiency curves, and operating pressure drop curves. This requirement is very professional. From the separation process calculation sheet, it is possible to see whether the technical party has data on the physicochemical properties of droplets and foam that affect gas-liquid separation under different operating conditions. The image below is a screenshot of a calculation document regarding the separation process using a separator from a certain technology provider, which can be used as a reference:

This post was last edited by luoli519 on 2024-4-8 at 16:39. It is also very important for the owner and the design institute to have a curve graph showing the separation efficiency of the separator. From the separation efficiency curve, it is possible to see not only the separation accuracy data corresponding to the 4N operating efficiency required by the client and the design institute (N=9, 4N=99.99%) ； At the same time, it is also possible to determine the separation efficiency of the separator for specific small-sized droplets and aerosols, such as those with a size of 1 micron. Here, we use the separation efficiency curve of a vane separator from a certain technology company as an example for discussion:

As can be seen from the above separation efficiency curve, the 4N separation accuracy of this separator is around 3 micrometers. The separation efficiency for 1-micron-sized heavy-phase carriers is approximately 90%. This means that for heavy-phase carriers with a size of 3 microns or more, 4N-level (99.99%) separation can be achieved. For 1-micron-sized heavy-phase carriers, a separation efficiency of about 90% can be achieved; approximately 10% of these 1-micron-sized heavy-phase carriers escape and cannot be separated or removed.