DRHX sensorless belt detection granted EU patent

The cross-functional collaboration between engineers in both hardware and software at OJ Electronics has not only led to the rather unique DRHX drive solution for rotary heat exchangers. Now the concept with its sensorless belt detection also holds an EU patent.

The DRHX drive with sensorless belt detection was originally developed in 2017, and now the European Patent Office has approved its originality and uniqueness.

“Of course, we are tremendously excited,” says Preben Jessen, Head of Drive Products at OJ Electronics, and continues: “It has been a long journey to get here. Such a process requires twice the work in the sense that you have to document everything twice – the technical documentation and then another for the judicial team, working through the patent process and approval”.

Cross-functional collaborations works

Preben worked closely together with a team of engineers in hardware and software to get the solution right. After thorough examining the system principles the team found that the traditional sensor setup could be simplified with a piece of software.

“We wanted to make a reliable solution that wouldn’t affect the heat regulation, when you run periodic tests,” says Jörn Petersen, Software Engineer and one of the key drivers behind the DRHX Drive. “To do that we needed to combine theory with field data and our years of experience in ventilation systems. But I think the result speaks for itself. We now have a solution with fewer components on the market”.

Removing the physical sensor adds benefits

The DRHX sensorless belt detection differs from traditional heat exchanger solutions, as the performance is monitored via software and not by a physical sensor. Basically, it works by measuring the acceleration of the motor after applying a short (100 ms) increase in output current. The internal rotor guard will then detect the acceleration of the motor. If it exceed a defined limit it means the belt is not there and the motor is only spinning the pulley and not the rotor wheel.

“Usually, you would have to stop the system to conduct these tests,” Jörn Petersen explains.

“With the DRHX the system conducts the test on-the-fly every 10 seconds. This is not only convenient for people working in the building, depending on flawless ventilation. It also allows system owners to respond quickly in case of failure and call for preventive maintenance in due time”.

Jørn Petersen, Software Engineer at OJ Electronics

The most obvious benefit with this new solution, however, is the fact that it is a more simple setup, consisting of fewer parts, which makes it easier to assemble at a lower cost.

Patents provide a competitive edge

Getting a patent through the European Patent Office is not just a morale boost for OJ employees. It also allows customers to differentiate further in a competitive market. According to Preben Jessen patents often manifest all the way through the value chain.

“Our patents benefit our customers too. Using a patented OJ product your solution is unique as well as protected,” he says. “Being a part of our customers’ solutions, we share the mark of documented innovation with them. So, it is a win-win” for all in the value chain.

“I’m sure customers and vendors who have been with us for years acknowledge us as an innovative partner. But, holding patents such as this one helps remind ourselves – all of us – just how much we push the envelope every day,” he says.

If you want to know more about the EU patent or how a DRHX solution can be tailored and integrated with your heat exchanger solution, reach out to Preben Jessen below.

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Preben Jessen, Head of Drive Products

+45 24 99 39 46 [email protected] Rotor products