Vapour recovery systems

Basic Operation of a VRU 

A basic vapour recovery unit system comprises a pressure swing absorption (PSA) process with two activated carbon bed vessels, alternating on a 15 minute time cycle.

Regeneration of the carbon reactors is accomplished primarily by vessel evacuation with a vacuum pump to a pressure level of-27 Hg (3 Hg absolute) and secondly, with ambient air purge into the bed in a controlled manner during the last 25% of the regeneration cycle.

The VOCs desorbed from the carbon during reactor regeneration are effectively recovered in a single step process that is absorption in a packed tower, counter current flow, absorber. Supply tank absorbent is pumped on skid for use as lean oil in the absorber and as a heat exchange fluid for the vacuum pump.

All product recovered by the system is pumped back to the absorbent supply tank mentioned. Here the enriched recovered liquid product is allowed to disperse throughout the supply tank environment.

We offer both the dry vacuum pump regeneration system as well as the liquid ring regeneration system.

VRU Features

Using their many years field service experience, Flotech have engineered their systems to incorporate unique design features that exceed industry needs – these include:

• Patented auto tuned vent and regeneration valves to protect vacuum pumps and carbon; increasing the life of the carbon.
• Patented return pump variable frequency drive level control to prevent gasoline spills.
• Self cleaning absorber tower with dished head bottom to eliminate confined space entry.
• Complete HMI control of all components and set points to allow for ease of operation.
• Remote web access for troubleshooting to reduce downtime.
• Historical trending of all VRU parameters and alarms.
• Skid mounted system; shipped and installed in four major parts.
• All components mounted and completely wired from the factory to skid mounted junction boxes.
• Skid and components designed for easy accessibility for maintenance and system checks.
• Reporting package specifically designed to meet Subpart BBBBBB regulations.
• Smallest industry footprint allows for reduced civil installation cost.
• Lowest industry energy consumption; reduces energy consumption on average 50% over competitive models.
• Typical return on investment less than 1 year; providing a quick payback and immediate profit increase.
• Robust design proven to pass HAZOP reviews by major oil companies globally.