Scaling in the cooling system of air separation equipment is the result of multiple factors (water quality, temperature, flow rate) working together.
The scaling effect on the cooling system of air separation equipment will significantly reduce the heat exchange efficiency, requiring a significant increase in energy consumption to maintain the cooling effect. The concentration of local media under the scale layer causes pitting and pitting corrosion, and the corrosion rate is several times faster than when there is no scale.
Pipelines are prone to blockage due to scaling, causing water flow interruption and forcing equipment shutdown. Scaling may cause a decrease in the adsorption performance of molecular sieves, leading to excessive CO ₂ and the formation of dry ice blocking the cold box, resulting in insufficient oxygen and system ice blockage. Emergency shutdown is required for treatment; Frequent cleaning of equipment, replacement of pipelines and spare parts significantly increases maintenance frequency and costs.
Preventive measures: Water quality pretreatment and optimization can remove calcium and magnesium ions through ion exchange or adding chemicals (such as lime); Control the conductivity of circulating water below 1000 μ s/cm to avoid excessive concentration of salts; Add scale inhibitors (such as polyphosphate) to the inlet pipe of the low-temperature water pump to increase the concentration of chemicals in the low-temperature area; Add sulfuric acid or hydrochloric acid in moderation to reduce pH and alkalinity, and inhibit the formation of carbonate scale; Increase the flow rate of circulating water and utilize the flushing force of water flow to reduce the deposition of scale layer; Introducing magnetic fields or electronic descaling devices to alter the structure of water molecules and reduce the tendency for scaling; Clean heat exchangers, pipelines, and nozzles quarterly to remove soft dirt and biofouling; Daily monitoring of pH value, conductivity, and alkalinity, timely adjustment of treatment plan to avoid scaling due to decreased salt solubility in the low-temperature range; Control the intake temperature to prevent a chain reaction of scaling caused by a decrease in adsorption performance.
