The problems of high temperature at the top and large reflux in the deep processing distillation column for coal tar
Thread Content
Our company operates a tar processing plant with a capacity of 150,000 tons per year. After 12 years of operation, the temperature at the top of the distillation column in the plant area has risen from 110°C when the plant started operating in 2012 to 136°C. Meanwhile, the amount of light oil returning to the top of the column has increased from 7 tons per hour to 12.5 tons per hour, and the cause of this phenomenon has not been identified yet. We have checked various aspects, including raw materials and production indicators at all preceding and subsequent processes, but found no problems. Currently, only the distillation column itself remains unchecked. This is a column equipped with inclined-hole trays; it has not been inspected or maintained since its commissioning 12 years ago. Please, masters, help analyze what exactly is the reason. Thank you.
Based on what you’ve described, the increase in temperature at the top of the fractionation column and the rise in reflux may be caused by scaling inside the column or damage to the trays. Prolonged operation without inspection and maintenance can lead to tray blockage or reduced efficiency. It is recommended to conduct a thorough inspection of the distillation column, with a focus on the integrity and cleanliness of the trays. If any blockages or damage to the trays are found, they should be cleaned or replaced. At the same time, check whether there are any other abnormalities in the tower, such as damage to its internal structure or corrosion; comprehensive handling should be sufficient to resolve the issue. .
Problems with the distillation column can be caused by the following factors: 1. Coking or blockage inside the column: Prolonged operation without maintenance and cleaning can lead to coking or blockage in the tray channels, the packing inside the column, or the catalyst, which reduces the heat transfer efficiency; as a result, it is necessary to increase the temperature at the top of the column to meet production requirements. 2. Internal equipment wear: After 12 years of operation, components inside the tower (such as trays) may become worn or deformed, affecting the normal distribution of materials and mass transfer efficiency. 3. System leakage: Aging of the equipment may cause minor leaks in the system, affecting the reflux rate and operating pressure, and thus impacting the separation efficiency and thermal balance. It is recommended to conduct a thorough inspection and necessary maintenance of the distillation column, particularly to check whether the trays are clogged or damaged, as well as to look for any leaks or other mechanical damage. .
The likelihood of clogging is low; the chance of tray damage is higher
Has the fuel consumption increased?