Gas issues caused by sunlight exposure on the transmission pipelines in Class A tank farms
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A new Class A tank area has been established, containing dichloromethane, propanone, and other solvents with low boiling points. These substances are transported via pipelines to the workshops for use, and measurement is required. In hot summer weather, exposure to sunlight causes the stainless steel pipelines installed on outdoor racks to reach temperatures of 50 to 60 degrees Celsius. The pipelines are equipped with pressure relief devices, and the discharge outlets are connected to storage tanks. Vaporization leads to an increase in pipeline pressure, causing the liquid inside the pipelines to return to the storage tanks. I’m not sure if anyone else has encountered similar situations. I’m mainly concerned about two issues: first, the issue of measurement – to what extent does a mass flow meter perform well under such conditions? In this case, more than 60% of the gas in pipes that are at least 100 meters long passes through the flow meter before entering the target container. Can the mass of this gas be measured accurately? Although it’s impossible to completely condense the gas, there is still some degree of error. Secondly, there are quite a few issues related to VOCs. Dichloromethane cannot be fed into the incinerator, and condensation-based collection methods are not very effective; resin adsorption is also required, which is quite troublesome. Therefore, I’m seeking advice from everyone on any good ways to solve this problem
Insulate the pipes, or build shelters along their length to block the sun
Insulating the pipes reduces heat absorption
Insulation doesn’t solve all problems; besides this, are there any other measures?
I have encountered similar situations; the following approach can be used as a reference: Add a return line at the end of the pump discharge pipeline, and use a heat exchanger cooled by chilled water at around 5°C to achieve condensation cooling. In this way, reflux can occur before discharge, preventing vaporization of the material in the discharge pipeline. Normally, only the side of the heat exchanger in the material and storage tank system remains unobstructed, which results in very little vaporization when the material returns to the storage tank ； Additionally, such materials must be cooled in summer; otherwise, it will be difficult to handle the VOCS. Pay attention to controlling the temperature inside the tank, and establish procedures for circulating cooling based on the temperature within the tank.
It is sufficient to insulate the entire pipeline, including the pump, as the materials inside the storage tank have already been subjected to cryogenic treatment
Dichloromethane has a very low boiling point, so pipes and equipment must be insulated