Literally in a few seconds you know you’re onto a winner!

I must admit that I personally am not ‘big’ on the Winter Olympics, however I sat spellbound watching Lizzy Yarnold win the women’s skeleton event – a real British gold medal ‘slider’. She hurtled down the ice tunnel with its numerous banked curves, covering the 1,500 metre course in just over 58 seconds.

Gold Medal winner Lizzy Yarnold    

The sport evolved in the Swiss resort of St Moritz in the late 19th century when wealthy British tourists took to cavorting around town on sleds, looking apparently, like skeletons. The sport featured in the 1928 and 1948 Olympics, with Britain bagging bronze both times, before sitting out the next 54 years. It was reinstated for Salt Lake City in 2002.

It was the sheer speed and power produced by Lizzy in order to cover every inch of the ice track to quickly prove that she was a winner that made me think about the sonic cleaning power of Primasonics Acoustic Cleaners. Within boiler plants for example, the powerful but totally safe sonic sound waves travel at 344 m per second an in a 360° radius to prevent ash from building on boiler tubes, economisers, air heaters, filters, ESPs and SCRs. Just a few seconds ‘sounding’ at periodic intervals is all it takes to prove that acoustic cleaning is a real ‘gold medal winner’. Find out more at www.primasonics.com & www.quattrosonics.com

Boiler Plant Acoustic Cleaner 

Blowing Off Steam vs The Beauty Of Acoustics

In March 2008 I wrote my first blog post about soot blowers. At that time, particularly within the power generation industry, steam soot blowers were the most common means by which plant engineers endeavoured to keep boiler soot and ash build-up under control. As I wrote at the time, steam soot blowers were not without their problems, however, and acoustic cleaning presented a better alternative.

Five and a half years on, I am delighted to report that the perception of power plant operators has changed and there has been a massive swing in favour of adopting acoustic cleaning technology in preference to traditional steam soot blowers. 

Ineffective steam soot blower (on left) installed into boiler
Acoustic cleaner (on right) subsequently installed to improve boiler efficiency

So what would account for such a radical change? Well, because steam soot blowers rely on high pressure, boiler tube erosion can occur. This in turn reduces the boiler's efficiency and incurs repair cost. Also, the jet of steam and air generated by the soot blower is limited in the amount of surface area it can reach so build-up of soot and ash can take place in other areas.

Here is a YouTube video clip we came across which shows a steam soot blower working. For anyone unfamiliar with steam soot blowing, you could be forgiven for thinking that nothing is happening when you first watch the video. Then at around 50 seconds you can hear the steam. The principle of the idea is to clean the boiler so that the boiler, in turn, can make steam and send it to a turbine where it is converted into rotational movement and then into electricity and then of course into money. Looking at what is happening through our 'technical' eyes, we see two issues at play here, neither of which is good for the power plant:


1. For the soot blower to work, valuable steam generated by the plant has to be diverted to it and away from the money making equipment.

2. When you hear the steam in the video you can actually see it leaking out of the seals and being wasted. The steam should be going off to serve a useful purpose but here it's the opposite, going back into the gas path.

With acoustic cleaners, no steam is required for their operation, there's no risk of tube erosion or corrosion and a greater surface area of cleaning can be covered. Plant engineers, to their credit, seem to have finally woken up to the reality of savings both financially and in terms of downtime that can be achieved using acoustic cleaning systems. The future of boiler cleaning in power plants can therefore look to a much brighter and efficient future.

My passion for the science of acoustics, however, is not limited to cleaning power plant boilers. It encompasses many things, one in particular being Jazz music which I have written about on this blog several times before. Here is a video that our Technical Director Alex Bergus came across which demonstrates what makes acoustics so fascinating.

You might at first think this is in slow motion but it's not. It was filmed using a camera with a high shutter speed.

Here is how Alex describes the clip ....
"Look at the lovely wave forms ... if you knew the distance between the bridge and where the string was being held down, then from some of the shots not only could you calculate the note but also the number of harmonics!"

How we love the science of acoustics :)

The Pop & Swing Of Economiser Cleaning Success

Most successful outcomes in industry are the result of the ‘appliance of science’. The success story I’d like to share with you today is a great example of that, except that it has one more ingredient - the ability to pop and swing!

One of my earliest blog posts recalled a trip to London to visit London Waste, a rather special power generation plant which converts household waste to energy. They were struggling with material build-up in one of the boiler economisers. Steam soot blowers, water sprays, manual cleaning and grit blasting had hitherto been their adopted methods of economiser cleaning but were not proving effective enough. Also it was not cost effective with periodic downtime of up to 3 days and a cost implication of circa £70,000. So the plant manager was eager to try our acoustic cleaners. Naturally, he needed to discuss the idea in detail to be sure that it was the right choice, hence my trip.

However, the success story that resulted might never have happened had I declined the invitation to take a closer look at the economiser section itself. The plant manager was lithe and fit whereas I …. well, let’s just say I was in a different class, so several leaps of faith were required.

His instructions of “Just pop through that hatch up there” and “Just swing your legs round here” still echo in my mind with a sense of fear and trepidation – and that’s five years on!

The reward for my endeavours? The following year saw 1 x PAS 60 curved acoustic cleaner and 2 of our PAS 75 units installed at the plant.

Two years further on and the plant was so pleased with the improved efficiency of the struggling economiser that a further 4 x curved PAS60 and 8 x PAS 75 were purchased and installed to help the remaining 4 boiler economisers.

PAS75 acoustic cleaner installed on economiser

Another two years later (early 2013), I was invited to return to the plant to look at the problems caused by fine ash in their filter bank (blocking of the filter bags). Following my recommendations, a series of our acoustic cleaners was installed in all these units. (Another story in itself, details of which will come later!)

I am most grateful to London Waste for entrusting their business to my company and also for granting permission to publish a detailed case study which is now available on our website. You can read and download the pdf by visiting our case studies page.

Dealing Acoustically With Boiler Corrosion

Corrosion is one of the main causes of reduced reliability in steam generating systems and the industry in general pays a heavy price for this problem of boiler system corrosion.

The majority of corrosion problems occur in the hottest areas of the boiler- the water wall, screen, and superheater tubes as well as in economizers, de-aerators and feedwater heaters.

The most common causes of corrosion are dissolved gases (primarily oxygen and carbon dioxide), under-deposit attack, low pH, and attack of areas weakened by mechanical stress, leading to stress and fatigue cracking.

One way to reduce mechanical stress is to remove any existing steam soot blowers which were installed to try and remove boiler fouling and slagging and replace them with acoustic cleaners - aka 'sonic soot blowers'. This is an interesting page worth reading about the mechanisms of steam soot blower erosion.
 
Steam soot blowers employ high pressure superheated steam and air every 8 hours or so to try and dislodge sintered-on ash covering the tube banks. Sonic soot blowers, on the other hand, use powerful but totally non-destructive sonic sound waves for a few seconds every few minutes. These sound waves reach every exposed surface, exciting the ash and thus debonding it into the gas stream.

Acoustic cleaning boiler application

Also worth noting is that sonic soot blowers operate at totally safe sound frequencies in the range of 350 Hz down to 60 Hz which are way above the mechanical resonating frequencies of steel. The result? Effective, ongoing particulate de-bonding with absolutely no risk of causing mechanical stress. Surely a Win-Win result!

Read more about acoustic cleaners for boiler cleaning

Cement Silo Cleaning South America

Silo cleaning and boiler cleaning are two of the most common and important issues that industrial plants have to deal with today. Proper material flow in silos and efficient boiler performance in industrial plant operations, however, are not without their problems which is where we come in!

We have provided acoustic cleaning systems for this type of application for many years now and in many countries around the world. Indeed, this year has seen an expansion of our sales and network agents into new territories .... in particular South America.

We now have agents in Chile and Brazil and have achieved sales to Mexico, Argentina and Columbia as well. What is interesting is the main type of operation where our acoustic cleaners have been installed in these South American countries ... cement and wood processing (silos and boilers). Again, proof that these two areas of industrial operations are key to success.

Long may we be able to contribute to that success with our innovative acoustic cleaners.

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