U-trap Refill Automator Guards Against Virus Spread

The new version of the device is equipped with a larger storage tank so that users can refill the water tank less frequently.

(From left) Hong Kong Institute of Vocational Education (Sha Tin) Department of Engineering Lecturer Kelvin To, student Tom Yeung, Bonnie Ho, and Workplace Learning and Assessment Project Team (Engineering Programmes) Project Officer Benson Hung work together to invent the “U-trap Refill Automator".

Floor drains with U-traps are no strangers to Hong Kong people who have experienced the pandemic outbreaks of COVID-19 and SARS. Ensuring U-traps to be regularly filled with water is one of the important defences against the spreading of diseases at home. Last year, an easy-to-use “U-trap Refill Automator” was invented by a group of teachers and recent graduates of Institute of Vocational Education (IVE) to help elderly and people with disabilities seal their U-traps with adequate water thus preventing viruses from entering their homes. This innovative design has won the Gold Award at the URA’s Innovative Design Competition.

A user-friendly device, the “U-trap Refill Automator” only requires users to place the box-like apparatus near the drain and fill the storage tank with water, then the ultrasonic sensor of the device will automatically detect the water level in U-traps. Once the water level falls below a certain low point, a signal will be sent to the electronic control panel, which will then “command” the device to release water into the pipes.

Users need only to place the box-like apparatus near the drain and fill the storage tank with water once in every three weeks or a month, then the ultrasonic sensor will automatically detect the water level in U-traps and “command” the “U-trap Refill Automator” to release water into the pipes when the water level drops below a certain low point.

Having adopted IoT technology, the second generation of the device can display water levels inside the U-trap on mobile phones.

In order to assist the IVE team to further improve the design, apart from providing some vacant units for them to conduct on-site trials, the URA has also given them professional advice on the design of drainage pipes. As a result, the “U-trap Refill Automator” has been enhanced with some new features that can fit both the wall and floor drains. Moreover, the new versionis now equipped with a larger storage tank so that elderly users can fill the water tank less frequently.

In response to the recent outbreak of COVID-19 in many old buildings, the URA has decided to commission the production of the basic version of the U-trap Refill Automator after discussing with the IVE team. Equipped with a built-in timer function, the device would automatically fill the U-trap with clean water at regular intervals to ensure that the U-trap is maintained with water seal to prevent the spreading of virus. The water storage tank is also fitted with a water level sensor and indicator light. When the water storage capacity of the device drops to a certain level, the indicator light will be switched on to remind the user to refill the water tank. The URA expects the first batch of 2,000 U-trap Refill Automators to be delivered to and applied in units of the four rehousing blocks as well as the properties acquired under redevelopment by mid-2021.

In addition, the IVE team has added a lot of creative elements in the design of their second-generation device, such as the use of IoT technology to enable users to preset and remotely control it through mobile apps, monitor the U-trap around the clock and allow users to choose between automatic or manual mode of water refilling. The system can also remind users to refill water in the storage tank via SMS and email.