The heat exchanger bundles in the purification columns at AnQore had become so contaminated that their capacity had fallen considerably. Due to the contamination that had built up, flushing the columns was becoming more and more ineffective, even when using a spraying robot. The decision was taken to move over to ultrasonic cleaning. The results exceeded our expectations.
AnQore is keen to maximize output
AnQore’s Edo Beijer (Assistant Production Manager) explains: “Generally speaking, the bundles that provide heat to the purification columns have to be dismantled and hosed down every 150 days. Some years ago, we switched to using a spraying robot, because we were no longer able to wash away the dirt by hand. The build-up of dirt resulted in a reduced capacity of the bundles, meaning that they only performed effectively for between 50 and 70 days. This is at odds with our aim at AnQore to maximize output.”
Working with Reym B.V.
Mariana Fonseca (Process Engineer at Sitech) and Paul Cremers (Production Staff at AnQore) have spent some time now looking into the possibilities of ultrasonic cleaning, but are still trying to come up with a concrete business case. Mariana explains: “Based on the agreed scope, we looked into two options: cleaning at the Chemelot site itself or cleaning at the supplier’s premises. Ultimately, the second option was the preferred choice due to safety considerations. After speaking to various suppliers, we decided to join forces with Reym B.V. They operate an ultrasonic washing station in Rotterdam, where we can bring the bundles in sealed big bags.”
Imploding vapor bubbles
How does ultrasonic cleaning work? Jaap Giesen, project manager at Reym Sittard, explains: “The procedure involves guiding ultrasonic waves through a tank containing cleaning solvent. These sound waves produce alternating high and low pressure. During the low pressure, millions of microscopic vapor bubbles are formed in the liquid in a process known as cavitation. These bubbles implode when the pressure is high. The energy released in this process ensures that the dirt comes loose. The implosions work like tiny brushes in all directions, on all the surfaces and penetrate into all the cavities and holes.”
As good as new
The result is astounding, and AnQore have been very impressed. Mariana: “The bundles now look as clean as they did years ago. We have high hopes that they will now only need to be cleaned every 150 days. We are delighted, and will be arranging for the other 3 bundles to undergo ultrasonic cleaning soon too. In the future, we will try to tackle this job during a turnaround.”
Widely applicable technology
“Ultrasonic cleaning is widely applicable, in combination with other techniques,” says Jaap. Marco: “For our part at Sourcing, we will be using this business case to convince other plants to make use of this technology, which is applicable to many different types of equipment.”