Enhancing Life of Ultrasonic Cleaners

                                 

Just recently, I read somewhere that villagers in Haryana bought massive amounts of  gold from a particular man just before the great Recession in 2008. Apparently, the con man said he had massive debts to pay off for his factories and was selling the gold at half the price. The public bought the yellow metal. It was Gold..but just about 20% of it and the rest 80% was copper.

Now.. Isn’t that a GROSS? Buying yellow metal instead of gold, just because the colours are the same. About 45 people were done in!

Unfortunately, such things happen regularly in the industry. Unless one buys from a BIS certified shop or material, one can't be sure. It’s also rumoured that many jewellery stores are still selling higher percentages of copper in gold. The issue said to be rampant in other forms of valuables like diamonds and platinum as well.

This phenomenon is not restricted to India alone, but most parts of the world where Standardisation of the Value is not performed.

Industrial Products and consumables are also affected where purchases are based on a single page ‘literature’.

I am narrating an experience, similar to which many of you may have already experienced.

We have a Electronic Security Division and had quoted in a tender at AAI for installation of CCTV cameras at the airport. The specs called for 1200 tvl (TV Lines) and Day night Functionality of certain High Performance Cameras.

When bids were opened, we found some suppliers to have quoted at 40% lower than the estimated cost. The catalogue was the only proof of backing the claim. Any clarification required by the Airport from the supplier.. was made on a letterhead.

We had a situation where nobody could verify the claim that the cameras indeed had 1200tvl.  However due diligence and other factors were employed in subsequent tenders.

Care to be taken in Purchase of Ultrasonic Cleaners

Engineering Goods generally don’t have such issues, due to the availability of test houses and BIS, JIS, ASTM and other norms that have been made.

However, these will be difficult to prove in the Ultrasonic Cleaning Business. By making some hypothetical comparisons, I hope to draw your attention to some adversely affecting scenarios:

a) How can one be assured of a correct power rating of the Ultrasonic? Have we bought a 500 watt Ultrasonic or is it a re-labelled 300 Watt?

b)  Is the design good enough to ensure the entire tank gets the ultrasonic waves? Or is it active in some areas only?

c) Is the ultrasonic transducer working with 30,40, 50 or 90% efficiency? Imagine paying a market price of Rs.50,000/- for 250 Watt Single tank Cleaner. If a good Ultrasonic Cleaner works with 90% efficiency and the one we have purchased is working at 30% efficiency…its same as paying Rs.1, 50,000!

d)  Is there a guarantee on the life of the Ultrasonic? Can someone support it after warranty? When the Ultrasonic transducer fails, it is almost always necessary to change the tank too. Low cost Chinese models will find it hard placed to do so. By the way... I offer lifetime warranty on all transducers on our equipment!

 Why Transducers are Important

Transducers are of mainly of three types : Piezoelectric  and Magnetostrictive and Pull Push.

Piezoelectric is made of a piezo ceramic disc sandwiched between two strips of tin. When power is applied to the tin bits, it creates a displacement which is what creates the vibration. When the frequency of vibrations are high, it creates the cavitation in the tank through the stainless steel enclosure.

Magnetostrictive transducers are similar except that it has lead rings that can be activated for shrinkage by getting magnetized. The advantage is that the rings do not get magnetized over an extended period of time.

Pull Push transducers are fitted inside the tanks. They are rod like and have an insert sleeve with the cavitation being created on both ends of the rods. These transducers can produce about 98% efficiency.

To be really effective, three aspects have to be taken care of:

1) Bonding

2) Efficiency

3) Inertial Mass

Inertial mass is something like the pressure needed to create movement.. If you need to move a train, you need engine with power and momentum that is greater than the train.. Right?  Can’t move it with a matchstick. It doesn’t matter if the matchstick is held by a railway engine. It just won’t move.

The same way a loaded Ultrasonic tank (water plus material), will need a series of transducers, which are more heavier than the tank plus the liquid weight put together.

The book has an elaborate and simple explanation about transducers, That will also explain in detail, why efficiency and bonding are better with Magnetostrictive transducers.

Though there are other components to an Ultrasonic Cleaner, the heart is the transducer and its up to us to take a call on what is the long term cost we can pay , for Cleaning!