Ultrasound prevents environmental harm caused by industrial fouling

Published: October 16, 2017

Finnish company Altum Technologies is the first to use ‘power ultrasound’ to clean waste from industrial equipment with no production stoppages or disassembly. Sarah Harding, Editor of Speciality Chemicals Magazine, speaks to Altum’s CEO Matias Tainela about the technology.

Altum’s technology was developed in partnership with the University of Helsinki. It combines traditional ultrasonic cleaning with the ‘Internet of Things’ – through which it is possible to monitor, update and control the technology remotely – and advanced beamforming techniques to localize and clean a pre-defined target point. The devices attach to industrial equipment and emit precisely-pitched, high-power ultrasound waves that break up and disperse fouling in practically any equipment carrying fluids.

The theory

Ultrasonic cleaning uses cavitation/air bubbles induced by high frequency pressure to agitate a liquid. As the liquid is constantly “disturbed” by sound waves and microstreams are formed, the size of the air bubbles increase and just as its threshold is exceeded, the cavitation violently collapses. This collapse of the air bubble produces shockwaves with high forces onto the inner surface of the container holding the liquid and as such onto the fouling attached to that surface, thus detaching the substrate.

The approach

Ultrasound generating piezoelectric transducers are attached to the outer surface of the liquid container and focused at a specific target point/area for controlled maximum cleaning effect. These transducers produce an electrically oscillating ultrasonic wave (i.e. compression waves) in the liquid inside the container. The decrease in acoustic pressure (sound wave minima) results in the disturbance of the liquid and formation of air bubbles/cavitation with fluctuating diameters. Just as the cavitation threshold exceeds, these bubbles collapse with high amount of energy that removes the fouling from the surface.

“The main novelty of our technology is in our waveguiding software that directs sound waves very accurately towards sites suffering from fouling,” says Matias Tainela, CEO at Altum. “This permits extremely efficient cleaning.”

Furthermore, Altum is currently developing AI (artificial intelligence) for the software. Using AI, it will be possible to analyse, for example, the fouling rate taking place inside the production equipment. All of this enables optimization of the cleaning interval and, even more importantly, optimization of the production itself.

The benefits

 Our technology provides a unique system – it’s the only one in the world that is applied externally in any existing production environment, without making any changes to the equipment,” says Mr Tainela. “For manufacturers of speciality chemicals, a greatest benefit of the new technology is the fact that no stoppages are required for maintenance. This avoids the down-time, disassembly and general maintenance costs that are usually associated with cleaning fouling waste from industrial equipment.”

As well as offering more production time and avoiding stoppages to industrial systems, other benefits of the system include increased energy efficiency by up to 40%. This is achieved by avoiding the 40% energy efficiency that may be lost in heat exchangers not using the system; power ultrasound enables them to run constantly with best energy efficiency. The system also offers increased equipment lifetime, by avoiding the build-up of bacterial biofilm that can cause problems such as rust and corrosion, and it does not require the use of any chemicals, meaning that systems can be cleaned with drastically reduced chemical usage.

Case study: Chemicals industry, March 2017 The customer had purchased a plate and shell heat exchanger for its chemicals production site in late 2015. At first, production output rates, temperatures and pressures were all at optimal levels.

However, after just few months they noticed that the new heat exchanger had fouling issues. Flow rates were going down. During a normal maintenance break they decided to clean the heat exchanger, but hot pressure water and chemicals failed to have an effect, especially in the limited downtime available. Within another few months, the exchanger was totally blocked. Soda and dry-ice blasting failed to clean this crucial piece of equipment.

A new heat exchanger appeared to be the only option. Or was it?

The customer found Altum. After few discussions, Altum agreed to try its power ultrasound technology that was under development at that time. Within a day, the power ultrasound systems had cleaned the heat exchanger totally. Needless to say, the customer was extremely happy with the results.

The environment

These benefits mean that technology complies with tight environmental laws. Depending on the country (and industry), laws may differ, but as regulations tighten across the globe this technology can, for example, address limitations set on the amounts and types of chemicals permitted to clean fouling.

“With our unique technology we can increase the effect of chemicals enormously,” says Mr Tainela. “This is due to the phenomena called sonochemistry where you combine the best of the chemical reactivity to stimulating sound waves, in the case of ultrasound this stimulation is huge.”

He explains that, in chemical kinetics, it has been observed that ultrasound can greatly enhance chemical reactivity in a number of systems – by as much as a million-fold, effectively acting as a catalyst by exciting the atomic and molecular modes of the system (such as the vibrational, rotational, and translational modes).1 In addition, in reactions that use solids, ultrasound breaks up the solid pieces from the energy released from the bubbles created by cavitation collapsing through them. This gives the solid reactant a larger surface area for the reaction to proceed over, increasing the observed rate of reaction.

“In the future, our technology will be able to analyse this effect in concrete terms and adjust the amount of chemicals and sound needed to optimize the customer process efficiency to the maximum,” Mr Tainela promises.

The future

The power ultrasound technology system was launched in June 2017. But removing fouling from industrial equipment is just the beginning. Altum is looking to the future with plans to adapt the power ultrasound technology to purify water, treat contaminated soil, and eliminate bacteria such as Legionella (e.g. from ballast water management systems, or in the food industry).

“Altum aims to use the Power Ultrasound technology to cut production costs, increase employee safety, and diminish the negative impact of industry on people’s lives,” asserts Mr Tainela. “The system is modular through software and hardware parts, so it’s very flexible and we can create solutions for any specific needs in any industry sector – chemical production, the food industry, oil and gas, pulp and paper, energy and heat, mining and…. Well, anything else really!”

With the cost of managing fouling in heat exchangers totalling €30 billion in Europe alone, the potential applications for the technology are significant. Altum is backed by seed investment from Lifeline Ventures and by Tekes, the Finnish Funding Agency for Innovation. The technology is currently being tested in 15 customer cases across Finland, part of them have already shifted to long term leasing contracts, also they have international partners in the pipeline. For more information, visit altumtechnologies.com.

Reference1. KS Suslick, DJ Casadonte. Am Chem Soc 1987;109:3459.


Copyright © 2017 Mack Brooks Speciality Publishing.