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Why must an external steam-water separator be used in steam generators? According to the regulations on boilers in China’s \"Regulations on the Safety Supervision of Special Equipment,\" steam generators whose product of water capacity and pressure inside the boiler is less than 30 L fall into the category that does not require special inspection. More and more steam generators are replacing traditional volumetric boilers. Similar to the principle of traditional boilers, a steam generator is also a device that uses the thermal energy of fuel to heat water into steam. Steam generators have advantages such as small size, low space requirement, easy installation, high thermal efficiency, fast steam production speed, and intelligent control, which are why they are widely used. The efficiency and capacity of steam to carry and release heat are important indicators for evaluating a steam generator. One of the factors that affect the steam heat transfer capacity is the moisture content in the steam, that is, the steam dryness factor. Steam engineers always strive to provide saturated steam with a dryness factor of 1.0 at the point of use, or in other words, steam with a dryness degree of 100%. Therefore, the drier the steam, the better its quality, and the better the performance of the entire system. The steam generator uses high-efficiency heat exchange tubes for heating, as well as a flashing device to separate the vapor-water mixture. The vapor-water mixture containing dissolved minerals has a higher surface tension; due to the compact design of the steam generator, it is difficult to create sufficient space for separation and retention, which leads to vapor containing water – field investigations have shown that the dryness degree of the vapor is often below 90%. The steam generator uses high-efficiency heat exchange tubes to replace the volume of traditional boilers in order to cope with changes in load, and it indeed has an advantage in terms of the time required to generate steam for operation. However, at peak instantaneous loads, the steam generator finds it difficult to meet such demands through the evaporation of boiler water, as traditional boilers can do. In other words, it is the foaming caused by the steam supply not being sufficient to meet the demand; this phenomenon becomes more apparent especially when the actual operating pressure of the boiler is lower than the maximum operating pressure specified by the manufacturer. The problem of water in the steam generator is often subtle and difficult to detect. When wet steam causes damage to the steam system, it also results in the actual efficiency of the steam generator being much lower than its designed efficiency. Sufficient attention must be paid to this. Regardless of the factors, saturated water in steam is of no use at all. In the wet steam generated by flashing, most of the saturated water exists in the form of small water droplets, which are suspended within the steam. The presence of condensate can cause serious problems with steam usage. The mixture carried in the wet steam enters the products being heated by direct steam injection; if the products are required to meet very high hygiene standards, the contaminated products become waste and cannot be sold. Some processing techniques cannot involve wet steam, as it will affect the quality of the final product. A high-efficiency Watt steam-water separator is installed at the outlet of the steam generator to remove the saturated water from the wet steam. Due to the highly complex conditions regarding the state and distribution of water in the wet steam generated by the generator, it is often difficult to capture, separate, and discharge the saturated water contained in the steam generator. Only by using multi-stage, high-efficiency steam-water separators that combine baffle mechanisms, centrifugal forces, gravity, and adsorption techniques can effective separation be achieved.