Packing & Column Internals Installation & Maintenance

The installation and maintenance of packing & column internals is the key to ensure the smooth operation of column equipment. Here we will introduce installation and fault maintenance precautions.

Column Internals Installation

Column internals that require welding, such as packing supports, liquid collectors, gas-liquid distributors, etc., should preferably be completed before packing installation to prevent weld slag from entering the packing and causing a fire.

The oil layer on the surface of metal packing can easily catch fire under the high temperature conditions of weld slag, and plastic packing is even more prone to fire. Weld slag left in the column can also cause blockage of the liquid distributor and affect column efficiency.

If some components must be installed during or after packing installation, asbestos cloth or asbestos sheet should be laid below the welding to isolate it from the packing.

Correct Installation Steps:

  1. Install the packing supports.
  2. Install the packing.
  3. Install the packing fixing or hold down device and adjust it to the horizontal.
  4. Install the liquid distributor or redistributor, fix it, and adjust it to the horizontal.
  5. After installation, check it thoroughly.
A packed column taken under the blue sky
Packing Installation
Structured packing with textured and perforated corrugated plate display.
Structured Packing Installation
  • Structured Packing Installation
    To prevent gas-liquid wall flow phenomenon in the gap between structured packing and column wall, an anti-wall flow ring should be placed in the gap. This ring can be integrated with the packing or assembled separately inside the column.
  • Packing Oil Removal
    New packing surfaces are usually covered with a thin layer of oil, which is due to lubricating oil or rust preventive oil used during manufacturing or storage processes.
    Before putting into operation, this oil film should be removed to prevent it from reacting with the liquid or hindering the formation of a liquid film.
Random packing in different materials and structures are placed together.
Random Packing Installation
  • Random Packing Installation
    The random packing can be installed by using both wet filling and dry filling methods. Regardless of the method used, the random packing should be filled from the column wall towards the center to prevent bridging at the column wall. After the installation of each section of packing, check if the upper layer of packing is leveled, and if there are any uneven areas, it should be leveled.
  • Ceramic Packing Fragment Removal
    Before filling ceramic packing, any fragments should be sieved out. However, large pieces of broken packing can still be used, although there might be a decrease in flux and an increase in pressure drop, the separation efficiency will not be dropped.
Packed Column Common Fault Diagnosis & Troubleshooting

Packed columns that cannot reach the design indicators collectively referred to as failure. In the packed column operation, sometimes failure may caused due to one or more factors. Here we summarize some common fault diagnosis and treatment methods to ensure the efficient operation of the equipment.

Table 1: Common Fault Diagnosis & Troubleshooting
Causes Phenomenon Treatment Method
Uneven distribution of liquid distributor: 1. poor design; 2. distributor clogging, corrosion leakage; 3. poor installation level; 4. exceed the operating elasticity; 5. poor distributor liquid inlet The efficiency of the column is poor and the pressure drop does not vary much from design. It is possible to determine which distributor is poorly distributed based on the separation efficiency of each section of the column. 1. Improve the design, redesign and make the distributor; 2. Remove the clogging, repair or replace the distributor; 3. Reinstall and level; 4. Increase the opening or reduce the opening of the distributor; 5. Improve the liquid inlet.
Liquid collector leakage: the downcomer is too small or the inlet resistance is large, causing difficulty in downcomer and liquid leakage from the gas rising tube. It usually results in entrainment, increased pressure drop and decreased flux. Enlarge the downcomer or downcomer inlet.
Packing is clogged and coked, and plastic packing is softened. High resistance, low separation efficiency, low operating limit. Clean inside the column or remove and clean outside the column, replace the packing.
Low packing support openings Failure to reach the design load, advance liquid flooding, low separation efficiency under high load operations, and high efficiency under low load operations. Replace packing supports with sufficiently high openings.
Uneven gas distribution, usually no gas distributor at the gas phase inlet of the tower bottom. Reducing the gas phase load or increasing the reflux can significantly improve the separation efficiency. If the gas phase inlet is not provided with a distributor, it will cause entrainment, high pressure drop under high load operations. Sometimes the design load cannot be reached. Install additional gas distributors.