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The preparatory work before starting the machine is very important in actual production, and it includes the following aspects: Section 1 – Water testing. Water testing refers to using water to test the equipment; it is a common method for checking whether there are any leaks in the distillation unit system (including the main machinery, auxiliary equipment, piping, etc.). This method is simple and effective. A water test should be considered in any of the following situations: 1. If the unit is a brand-new complete set of equipment, a water test must be carried out after installation and before it is put into operation; this is the first inspection step before new equipment is brought online. 2. If some of the equipment in the original unit is to be upgraded, and it is confirmed that some of the original equipment is still in good condition, then only the new equipment can be tested with water; if necessary, the new and old equipment can both be tested simultaneously with water. 3. After a comprehensive overhaul or partial repair of the original unit, a water test should be conducted. 4. For original units that have been idle for a long time or have been out of operation for an extended period, a water test is also necessary. Due to long-term disuse, flange gaskets will shrink; adding water not only allows for the detection of leaks but also causes the gaskets to swell as a result of moisture absorption, while simultaneously serving to clean them. The water test can be carried out in the following sections: First, the main unit section, which pertains mainly to tower equipment; in multi-tower units, the water test can be conducted one by one or simultaneously, depending on the conditions. During water testing, water can be introduced into the towers using the vent valves built into each tower. Water flows downward through each level of trays to the bottom of the tower, and then it fills the entire tower from bottom to top. At the same time, the air inside the tower can also be pushed upward and discharged through the vent pipe at the top of the tower via the condensation system. Or open the tower top manhole or sight glass for venting. Once the entire tower is filled with water, wait for an appropriate amount of time and then inspect the tower carefully; any leaks should be addressed promptly. After the water test is complete, the valve at the bottom of the tower can be opened to drain the water slowly. Be sure to open the vent valve at the top of the tower as well, to prevent the equipment from being crushed by vacuum. Second, the auxiliary equipment section mainly consists of various types of heat exchangers. Such equipment must undergo a hydrostatic test before leaving the factory; if its quality is guaranteed, this test may be waived. However, considering the possibility of leaks due to handling and collisions during long-distance transportation, it is still necessary to conduct a hydrostatic test. Third, the piping section mainly refers to valves, pipe fittings, flanges, flow meters, and joints at various testing points. Section 2: Steam Testing Steam testing refers to the use of steam to test the equipment in the unit; it serves as the second step in checking whether there are any leaks in the distillation unit system. It is often the case that there are no leaks during water testing, but leaks may occur during steam testing. Compared to water testing, steam testing is more comprehensive; therefore, it represents a continuation of water testing. Steam testing serves an even further purpose; it can be regarded as a \"thermal film test\" of the unit’s performance under \"quasi\" production conditions. At this stage, by observing the general movement of the vapor-liquid contact device inside the tower, it is possible to get a basic understanding of its performance under actual production conditions and have a clear idea of how it will perform. If the steam testing phase is carried out immediately after the water testing phase, the step of filling the equipment with water can be omitted. After the water testing is completed and the water has been drained to an appropriate level, steam testing can begin. The term \"appropriate level\" depends on the internal structure of the tower equipment; in the case of a packed tower, the packing is at a wet state at this point. When the liquid level in the heating chamber is at 1/2 to ~2/3 of its capacity, steam can be introduced gradually to carry out heating. If the steam test is not carried out immediately after the water test, water should first be added to the tower before the steam test, so as to create the conditions mentioned above, and then steam should be introduced for heating. When heated to a certain degree and the shock noises caused by uneven temperature inside the tower have essentially disappeared, the steam supply can be increased slightly; once the steam is discharged through the vent valve at the top of the tower, the air valve can be closed. A large amount of steam will enter the condensation system, resulting in reflux within the tower. Once the gas-liquid flow within the tower is operating normally, the material pump can be started to pump water into the tower in order to conduct simulated production tests using water as a substitute for material. The entire unit then enters normal operation; at the same time, a thorough inspection of the unit is carried out, and any issues that may arise are addressed promptly. Section 3: Material Testing. As a precaution, small-scale material testing is often carried out after water testing and steam testing. This is done to identify any leaks, as well as to further assess the overall performance of the unit to determine whether it can operate properly over the long term and meet the specified production requirements. During the material testing phase, several issues need to be addressed: whether the unit’s load capacity and exhaustion capacity meet the design requirements. 1. Check whether there are any abnormal phenomena such as leaks in the entire unit, and address the existing problems promptly. 2. Is the adaptability between the main unit and the auxiliary units good? 3. Whether the coordination from supporting departments such as water, electricity, and steam is appropriate. 4. Whether all testing and display instruments are in good condition and accurate. Section 4: Preparing to Drive 1. First, contact all departments to get them ready for action. 2. Check the equipment and instruments to ensure they are in working condition. 3. Implement various emergency protection measures. Let’s stop the conversation here for now; we’ll have the chance to discuss the startup procedures for distillation towers with everyone in the future! ! Thank you all.