Fouling in heat exchangers can have a substantial impact on the operation of processing facilities. First and foremost, it inhibits the ability of the exchanger to recover heat from the product stream. In turn, more heat must be supplied by the furnace to raise the feed temperature to its specified setpoint, which increases fuel consumption and energy costs and decreases overall process efficiency.
Fouling also often leads to higher maintenance costs as a result of cleaning and repairs. High-pressure jetting is a highly effective method for performing cleaning; however, it typically requires equipment to be disassembled and heat exchangers to be bypassed. In facilities where bypassing units is not feasible, a total shutdown of the plant may be necessary, leading to production losses. Working on equipment, whether for cleaning or part replacements, also increases the risk of a leak or incident, requiring operators to employ additional safety measures to protect both the personnel performing the maintenance and the surrounding environment.
When properly applied, chemicals can be used to effectively prevent fouling in heat exchanger systems. Operators today have the option of using any number of treatment options to address fouling problems (corrosion inhibitors, dispersants, polymerization inhibitors, etc.), each of which provide unique advantages depending on the severity of the fouling and the individual needs of the processing facility. Identifying the specific type of fouling (organic or inorganic) plays an important role in choosing the most appropriate chemical treatment option as well.
In every case, process data should be used to define objectives prior to the beginning of treatment so that the applicable process parameters can be monitored and the effectiveness of the treatment method can be assessed.