What aspects should be considered when inspecting the packing in a packed tower?

The most important aspect is safety; first, the materials and load inside the tower must be completely removed； II. For towers handling flammable and explosive, toxic and harmful, or polluted/muddy materials, prior to maintenance, replacement and analysis must be carried out; once these checks are successful, blind plates should be installed at all inlets and outlets of the material flow to prevent harmful materials from entering the tower during inspection ； III. Relevant procedures must be followed before entering the device, and a dedicated person must be assigned for supervision, etc. There are many relevant precautions; it is recommended to look for safety-related information on this forum.

Clean the packing; replace or replenish any damaged parts. Clean the internal components and clear any blockages in the distribution holes. Tighten the bolts. Strengthen the supports. Clean the filter. If it is a stainless steel packing, it can be simply removed and cleaned; whereas if it is a ceramic ring packing or plastic packing, it needs to be replaced. Packing tower maintenance procedures: http://bbs.hcbbs.com/viewthread.php?tid=305469&highlight=%CB%FE%2B%BC%EC%D0%DE

Procedures for inspecting packed towers: Maintenance tasks include loading, unloading, cleaning, and screening the packing rings. Clean the paste-like substances and debris from the inner walls of the 2 towers. 3. Inspect the corrosion of the tower wall. 4. Remove rust (sandblast) from the inner wall of the tower locally (or entirely) depending on the degree of corrosion, and then apply anti-corrosion treatment. 5 Disassembly, cleaning, inspection, and repair of the spraying device. Inspection and repair of the grid plates. Cleaning, inspection, and replacement of the inlet and outlet pipes for Solution 6 and the associated valves. 7 Maintenance and cleaning of the level indicator device. 8. Cleaning and inspection of the demister device. 9 Check and adjust the verticality of the tower, then tighten the foundation bolts. 10 Check the tower foundation for cracks and settlement. 11 Check the outer surface for any abnormalities such as cracks, deformation, or localized overheating, and verify that the container’s anti-corrosion coating, insulation layer, and equipment nameplate are in good condition. Check for leaks in the welds of the nozzles and other pressure-bearing components of the 12 containers. 13 Conduct regular non-destructive testing in accordance with pressure vessel regulations and requirements. Maintenance methods and quality requirements. 1 Solution spray distribution device. Regarding the solution distribution plate: the central cylinder must be securely fixed; the local unevenness of the distribution plate shall not exceed 2 mm over a length of 300 mm, and its curvature across the entire surface shall not exceed 2.5 mm. The connection between each distribution plate and the frame must be tight, with a maximum allowable gap of 0.5 mm. The edges of the distribution plate and its sieve holes must be smooth. 2 pairs of solution nozzles: the tolerance for the horizontality of the nozzles is 2 mm. The axis alignment between its center and the tower’s center is allowed to have a tolerance of 3 mm, and the internal core as well as the spiral grooves must be smooth and free of contaminants. The filler grid plates should be flat, without damage or deformation. The installation center should be constructed strictly in accordance with the drawing requirements. 3. It is strictly prohibited to introduce damaged packing material during filling; the filling height and method must be carried out in strict accordance with the requirements specified in the drawings, with a tolerance of ±40 mm. The surface above the packing section must be flat, with a tolerance of 40 mm for unevenness. 4 Tower inspection. The lack of verticality of the tower shall not exceed 1/1000 of the tower height, with a maximum value of 30 mm. As for the straightness of the tower, when its height is greater than 20 meters, the maximum deviation shall also be 30 mm. The anti-corrosion coating on the tower shall have no bulges, cracks, or delamination. After applying the anti-corrosion coating, its curing time must be strictly ensured (depending on the properties of each type of coating). The insulation material for the tower (with external insulation) meets the requirements of the design drawings. 5 The level display instrument system should be sensitive and reliable. The 6 inlet and outlet valves should open and close smoothly, with no internal leakage when under pressure; the valve packing should be installed correctly, with each ring having a 30° bevel, and the cut positions of adjacent rings being offset by 120 degrees. 7 Corrosion inspection and treatment: The corrosion condition should be carefully inspected and measured. Scattered pitting, provided it meets the following conditions simultaneously, generally does not require treatment. The corrosion depth shall not exceed 1/5 of the wall thickness (excluding the corrosion allowance). Within a diameter of 200 mm, the total area of pitting corrosion shall not exceed 40 cm2. Within a diameter range of 200 mm, the total length of pitting along any diameter shall not exceed 40 mm. For uniform surface corrosion, if the remaining average wall thickness (after deducting the amount of corrosion that has occurred up to the next inspection period) meets the required strength criteria, no action is necessary. For non-uniform surface corrosion, if the strength is found to be satisfactory when checked based on the minimum remaining wall thickness (taking into account the amount of corrosion that will occur up to the next inspection period), no action may be required. Those that do not meet the above conditions can be subject to repair welding, surfacing welding, replacement, or disposal depending on the specific circumstances. 8 For surface and near-surface cracks, appropriate measures are taken based on the cause and severity to completely eliminate them (such as grinding, patching, or scrapping). When using grinding to eliminate surface corrosion defects, surface welding defects, or crack-like defects, surface flaw detection and thickness measurement should be carried out after grinding. If no further welding is performed, the ground area should have a smooth transition. The side slope should not be greater than 1:4. When using welding methods, the welding repair process should be evaluated in advance based on the welding procedure qualification. The welder must have a certification for that welding task. For any areas that require repair welding, appropriate methods should be used to eliminate the defects; when using carbon arc gouging to remove internal defects, grinding must also be carried out. Surface flaw detection tests should be performed to confirm that the defects have been completely removed before proceeding with the repair welding. The length of the repaired area should generally be no less than 100 mm. After repair welding, checks on the surface finish quality, as well as surface and internal non-destructive testing, must be conducted. For surface corrosion repair by surfacing, internal non-destructive testing is generally not required, but the surfacing surface should be polished to be smooth and even. For containers that require post-weld heat treatment, the areas that have been rewelded must undergo appropriate post-weld heat treatment. The quality of the welded area after repair must meet the relevant provisions specified in the \"Regulations on the Safety Supervision of Pressure Vessels\". 9 Pressure (hydrostatic) test: Fill the container with liquid (provide an exhaust port at the highest point of the container to remove all air). Only when the temperature of the container walls equals that of the liquid can the pressure be increased slowly to the specified test pressure and held for 30 minutes. Afterwards, the pressure is reduced to the design pressure and held for at least another 30 minutes, during which inspections are carried out. Acceptance 1: Acceptance shall be carried out in accordance with the maintenance quality standards specified in these regulations. 2. There are no debris inside the tower. 3. Before sealing, technicians must inspect and verify that all components within the tower as well as the filling material are properly installed, and that everything is in order. 4 It has complete maintenance and inspection records. 5. If it meets the above requirements, the acceptance procedures can be carried out as specified for handover to production. Safety precautions for maintenance: 1. When the system is shut down, the cooling and pressure reduction of the equipment must be carried out strictly in accordance with the operating procedures; it is not allowed to remove bolts or other fasteners while the container is still under pressure. 2 During the hydrostatic test, if any abnormal noises are heard, a drop in pressure occurs, the paint peels off, or there are abnormalities with the pressurization equipment, the test must be stopped immediately to determine the cause. 3 The newly erected scaffolding must be safe and reliable. 4. When entering the equipment for the first time, a \"Equipment Entry Permit\" must be obtained. 5. Welding work inside the tower must be carried out in accordance with relevant regulations, with special attention paid to the H2 level at the top of the tower. 6 When entering the equipment, only lanterns with a voltage of no more than 12 volts are allowed for lighting. For power supplies of testing instruments and maintenance tools that exceed the safe voltage level, insulated flexible wires must be used, with no joints in between, and a reliable grounding wire is required.