Chemicals maker warms to wireless

West Bromwich, UK – Robinson Brothers is employing energy-harvesting technology to make remote wireless temperature measurements at its West Midlands chemicals plant.

The West Bromwich-based speciality chemicals maker is trialling the use of transmitters on the steam main supplying its manufacturing plant.

The transmitter has operating for about three months now without drawing any power from its back-up battery, according to Tom Rutter, E&I manager at Robinson Brothers.

“It looks like it could go on forever, provided there’s steam flowing through the line,” Rutter commented.

The system was installed by integration firm ICA Services, which suggested exploring energy harvesting as a way of eliminating cabling costs in future instrumentation schemes at the West Midlands site.

The transmitter, from ABB, is powered by an on-board micro-thermoelectric generator (micro-TEG), which is driven by the temperature difference between the steam pipe and the ambient surroundings.

The micro-TEGs used in ABB’s WirelessHART temperature transmitters are designed to provide a robust and compact solution for energy harvesting from either hot or cold processes.

With many industrial processes, such as those at Robinson Brothers, having an abundance of heat, the power that can be delivered by TEGs is sufficient to operate wireless sensors in a variety of locations.

The system at Robinson Brothers needs a minimum temperature difference of around 30°C, which is easily achieved in this application where the steam flows at around 106°C and the ambient air is typically 26°C. The transmitter also has a built-in back-up battery which is not used during normal plant operation.

ICA Services engineers set up the transmitter to send data wirelessly to a remote wireless gateway, which feeds the signal into the site’s existing Ethernet network and then to an ABB SM500F data recorder.

“I don’t see any reason why we wouldn’t be using the energy harvesting technology again after such a successful trial,” concluded Rutter.

“We’ve already got over 10,000 measurement points around the site but we don’t have much wireless technology. It’s something we’ll be looking to do more of in future projects because there are terrific cabling costs involved in installing conventional instrumentation and the potential savings are obvious.”