“Reflucket” Reduces Water Waste From Reflux Condensers at Penn

Most reflux condensers in laboratories require a continuous flow of cooling water to condense solvent vapor. The source of this water is often directly from the tap and is sent back down the drain, which can waste over 13,000 gallons of water per year per device. During the I2SL Student Showcase April 17, a mechanical engineering student at the University of Pennsylvania (Penn), Anisha Karunakaran, described her work to reduce water waste from reflux condensers. Anisha’s solution was to develop a cost-effective water recirculating system that saves water and promotes safer lab operations.

As Anisha explained, there are safety risks with the traditional set-up of reflux condensers. Demand for building water throughout the day can create pressure differences in the faucet, which can cause the tubing to come off the faucet and flood the work area. Anisha provided an example of a forensic science lab that flooded in Washington, D.C., and resulted in $27,000 worth of damage. According to Penn’s Chemistry Building Administrator, Anisha said, an incident with a reflux condenser malfunctioning used to happen about every four months at the university.

Anisha observed that labs tried to address water from reflux condensers by creating do-it-yourself (DIY) recirculating devices from buckets and aquarium pumps. While the DIY system worked, researchers were concerned about the efficacy of this system, the time it took to manually assemble it, the amount of lab space it required, and the safety of a DIY system. Anisha researched alternatives such as recirculating chillers or waterless reflux condensers, but they were cost-prohibitive for many labs, so she created the “Reflucket,” a compact closed-loop reflux cooling system using the same principles as the aquarium pump and bucket method in a compact unit.

Anisha and her team designed 5-liter (7”x7”) and 9-liter (7”x9”) configurations. The 9-liter model is best for longer experiments that require more cooling stability. Each system uses a plastic container with a lid, two tubes that connect to the reflux condenser, an aquarium pump, and another tube that is used to fill the water container and drain after use. Anisha and her team created a flier with a seven-step process to assemble the Reflucket, which only requires drilling a few holes in the container and tape to mark the tubes. The system maintains constant water pressure and operates with room temperature water, without the need for ice or additional cooling. At $20 per unit, it is much more affordable than the alternatives, and ordering materials in bulk can reduce the costs even further.

The Reflucket was designed to be housed inside of a fume hood and easily hooks into the water line within a hood. Penn’s Clean Energy Conversions Laboratory researchers became early adopters and are continuing to use the Reflucket system. Anisha and her team have made manuals for implementation of the device and hope to promote it further on campus and more broadly!