Many liquid or slurry chemicals are stored for transportation between process operations using a pallet tank or drum. The fluids within the tanks often need protection from air and moisture to retain flavors and other properties as well as to prevent deterioration. Tank blanketing or padding the contents with an inert gas is the typical solution, but this presents several challenges, such as prohibiting the introduction of ambient air. Fortunately, Equilibar back pressure regulators can address the complications.
At the Tank Filling Station
In filling a container with product, the blanketing gas or vapors in the head space must be vented to a proper disposal process to meet air quality and safety codes. Connecting the tank to the disposal system via an Equilibar back pressure regulator achieves the goal of retaining a slight pressure on the product container, yet relieving the pressure as the container fills. Equilibar GS series back pressure regulators are ideal for this application and can be remotely controlled by several set point options including electro-pneumatic controllers driven by a process computer.
The blanketing gas can be air or an inert gas and the pressure needs to be precisely controlled. A pressure reducing regulator handles the primary pressure control task while the pressure is fine-tuned by the Equilibar.
In this phase of the process, the product fumes do come in contact with regulator, so material needs to be chemical resistant. Equilibar units are available in 316 Stainless steel and PVC or PVDF.
Emptying the tank
During emptying, an inert blanketing or padding gas should be introduced to the container to fill the void. Depending on the pressure resistance capabilities of the tank or drum, the pressure required can be as low as 2 in WC. If the container is capable of higher pressures, blanket gas pressure can be used to move the product out of the container. The set point regulators in the Equilibar product line can accommodate either situation.
For more information, see Equilibar’s tank blanketing application page.