Sixty Years of Acoustic Design!

This year is the 60^th anniversary of the First World War which began on July 28, 1914. No doubt that leading up to this historic date, our daily lives will be full of constant reminders of this horrific war in which more than nine million combatants were killed. However throughout all the suffering, some positives did emerge – new friendships were made, new loves flourished and the science of acoustics was developed.

World War one was a mixture of old and new fighting techniques. On one hand horses were still widely used and trench warfare was still to the fore. On the other, aircraft became an ever more important tool providing each side with the ability to attack the enemy in its home land.

New equipment had to be developed to warn of the danger of approaching aircraft and this is where the science of acoustics began to play an important role with the development of Acoustic Location Equipment as a means to supplement visual warning of an air attack. Here you can see an early example of detecting the low frequency sound waves emitted from the aircraft engines.

Primasonics International have developed this science of acoustics to a new and exciting level with their range of Acoustic Cleaners which are employed to debond particulate and aid material flow wherever ash, powders or granules are generated, manufactured or stored. Find out more about this practical and highly efficient method of industrial plant cleaning at – www.primasonics.com

Kolkata to Cairo, Munich & More: Acoustic Cleaning Travels

The sights and sounds recalled by myself and our Technical Director Alex Bergus when we have travelled overseas to visit our acoustic cleaning clients are often colourful and fascinating. We have shared many of these already in our acoustic cleaning blog and today we're sharing even more ... and introducing a new boy!

The sights - these can vary hugely, from familiar ones such as looking at blocked silos on a site inspection to coming across unusual cars such as this Ambassador in Kolkata (capital of West Bengal). In production since the late 1950s the 'Amby' is an iconic car in India, based on the 1950s British Morris Oxford and it's not every day that we get to see one!

 

The sounds - these are certainly no less varied. It might be the familiar sound one of our acoustic cleaners being tested after installation on a silo in the hot sun or conversely the unfamiliar grunt of a camel as it passes by on patrol at the Great Pyramids of Giza. Look closely in the photograph below (taken by Alex) and you will see the policeman on his camel. There’s also our post from July (click here) where you can see the camel in question close up!

It is not always hard work out under the hot sun of far flung destinations, however. From time to time we are invited to attend and often speak at international conferences and trade fairs. Here is Alex talking to attendees at a recent Waste to Energy conference in Munich. 

The photograph was taken by our new Marketing and Customer Service Manager Dan Keeling who took the opportunity to meet some of the European Waste to Energy industry's leading players.

Conferences such as these are great opportunities for us to spread the word about our innovative acoustic cleaning technologies and we relish the variety of questions put to us. For example, what are the benefits of acoustic cleaners and how do they compare to traditional steam soot blowers? We can readily answer these questions and it’s always great to be able to do this in person as we get the opportunity to demonstrate not only our expertise in the field but our passion!

However, for those of you that we don’t get to meet, here is a page of the most commonly asked questions we receive, including how the technology works, the importance of the shape, frequency ranges and compressed air requirements.  There are many more questions of course and there has not been one (yet!) that we’ve struggled to answer :)

Dynamic Cyclone Cleaning

1 billion tonnes of cement – that’s the estimated amount currently produced in the world per annum and with cement production involving the handling and processing of dry powder materials, it is not surprising that plant operatives are constantly on the lookout for solutions to their dry material build up problems.

We’ve talked before in our acoustic cleaning blog about  silo and id fan cleaning in cement plants and today we tackle another issue they have to deal with …. blockages in dynamic cyclones.

Dynamic cyclones can be prone to impeller blockage and damage. This in turn can cause cyclone blockages and prevent efficient up-stream equipment operation. With the installation of acoustic cleaners the airflow can be maintained correctly and solids separated by eliminating particulate build up.

Installation of our acoustic cleaners into a cyclone can produce huge savings over time and we have a wealth of experience in this particular application.

To demonstrate this, here are some of the initial key pieces of information we require to allow us to quote for cyclone cleaning:

•    Nature of material being collected
•    Temperature inside the cyclone
•    Percentage moisture content of the material
•    Cyclone size and material it’s constructed from
•    How fast the build-up occurs
•    Information about the inlet ductwork

Click here to view a typical arrangement of acoustic cleaner installation on a cyclone. You can also download our cyclone applications pdf where you will find a dimensional drawing to be completed. Once we receive the completed questionnaire, we can then assess the optimum type, size and number of acoustic cleaners likely to be required and offer our best quotation for their installation.

Our acoustic cleaners are also an effective material build-up solution for dynamic cyclones in carbon black plant operations where there is the added challenge of maintaining air flow and efficiency in static cyclones and their associated ductwork . Click here to read more about our involvement in the carbon black industry.

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

A Powerful Year For Acoustic Cleaning

As the year draws to a close it's natural to reflect upon significant events and achievements and I'm delighted to say that 2012 has been a good year for our acoustic cleaning technology. Our acoustic cleaners have continued to be in demand, having been installed this year in sites and plants around the world from the USA to India and across to the Far East and Australia.

Perhaps the most significant achievement has been the increased demand and subsequent popularity of our PAS 60 acoustic cleaner, the most powerful audiosonics acoustic cleaner in the world.

Q: What makes it so special?
A: Its incredible long range power.

Such power makes this acoustic cleaner ideal for use in very large capacity silos (circa 30,000T). Such a size of silo presents a potentially serious problem for plant operators should it suffer a build up of material on its sidewalls.

The PAS-60 - which comes in a straight or curved shape - has the power and capacity to prevent that buildup.

It is also well suited to boiler plants and sites that use electrostatic precipitators and selective catalytic reduction.

This acoustic cleaner was years in development so it has been truly rewarding to see the value it is now bringing to industries worldwide. Looking forward to 2013 and expanding that success even further!

For The Love Of Acoustics

There has been a fascination with the science of acoustics for a very long time.

When humans first used reeds from which to make flutes, for example, they realised that acoustics could add a new and pleasurable dimension to life that led to the development of musical instruments.

In the scientific world, imaginative thinkers such as Leonardo da Vinci made great strides forward within the field of underwater acoustics. In the late 15th century he wrote "If you cause your ship to stop and place the head of a long tube in the water and place the outer extremity to your ear, you will hear ships at a great distance from you." (More on this here http://en.wikipedia.org/wiki/Underwater_acoustics)

In today's world, the fascination of acoustics continues. Here are some examples:

PAS-60 acoustic cleaner

• Acoustic cleaning - here at Primasonics we are proud to have developed the world's most powerful acoustic cleaner, the PAS-60. Read about it here
  
• Thermoacoustics - where sound waves are used to create a thermal gradient and effectively a means of refrigeration. Check out this YouTube video of a thermoacoustic refrigerator 
  
• Acoustic Levitation - using a transducer and reflector, sound waves can suspend objects in midair. There's some good reading matter on how acoustic levitation works including this page.

 

Consider the 4 different types of 'acoustic' science mentioned above (underwater acoustics, acoustic cleaning, thermoacoustics, acoustic levitation) and it is clear that this is an area of science with enormous potential still yet to be discovered. We live in exciting times!

Cement Industry Needs Acoustic Cleaners

The cement industry is one of the foremost industries to use acoustic cleaning to deal with and, indeed, combat material build up problems.

From dealing with ratholing and bridging problems in silos to the necessary maintenance of id fans, filters and ESPs, acoustic cleaning has become established as one of the key components of efficient cement plant operations. Read more about cement plant cleaning and silo cleaning.

We have over fifteen years of experience dealing with cement plants around the world and regularly receive emails from delighted clients who have experienced significant improvement in their cement plant operations due to our acoustic cleaning technology. A good example is that of a cement plant client who had been suffering unscheduled shutdowns because of material build up on an ID fan. After the installation of one of our acoustic cleaners they couldn't wait to let us know that these unscheduled outages had ceased. Read more on our acoustic cleaning referrals page.

Our success within the cement industry has led to our being asked to share our expertise by attending  cement conferences and trade fairs around the world. As referred to in our last blog post, our Technical Director Mr. Alex Bergus recently conducted a seminar on acoustic cleaning in Indonesia. He then went on to attend the Cemtech Asia 2012 event - photographed below at the Primasonics International stand. 

Seminar Demand For Acoustic Cleaning Expertise

Acoustic cleaning is now well established as a preferred and innovative means of dealing with material build up - a problem encountered by many industries. The resulting demand for our acoustic cleaners seems to increase every year as does the demand for our expertise at conferences and seminars.

Here is our Technical Director, Alex Bergus, photographed whilst conducting a seminar on acoustic cleaning technology at a recent conference in Indonesia.

 

For anyone who cannot get to such seminars but who is interested in learning more about acoustic cleaning technology and the benefits it brings, you may find the following information useful:

Concept of Acoustic Cleaning
Acoustic Cleaning FAQ