Miodrag,

 

See initial answers in red below, more to follow.

 

 

 

Hi Chris,

 

Please see the comments and answers below:

 

 

Miodrag,

 

Attached are 2 photos of the Russian transducers attached to the heat exchanger and one photo of the two controllers. 

 

Are you satisfied with results when using Russian transducers? 

They have definitely shown a major improvement since we put them into operation.  We have one heat exchanger with transducers and one without in a parallel installation.  The unit without has fouled badly twice since then and required disassembly and manual cleaning, but we have not had to clean the unit with transducers yet in about 3 months.

Are you operating Russian transducers continuously (7/24), or from time to time?

Continuously.

Did you notice significant (increased) heating on Russian transducers?

If you mean increased thermal performance of the heat exchanger over a clean unit, we do not know as the load on the units change continuously throughout the day.  It may be possible the vibrations have increased performance.  If you mean do the transducers get hot, they are warm but not too hot to touch.

What is the operating power of Russian transducers?  Is this a high-amplitude operation, or just moderate, low amplitude ultrasonic agitation?

We will have to get our electronics guru to check out the power consumption and maybe frequency when he returns from vacation.  I doubt that it is what you would call high amplitude as I do not feel any vibration when holding an active transducers in my hand.  There is a noticeable noise with 4 transducers on one heat exchanger.

How many transducers are connected to the same Russian ultrasonic generator?  Is this the case that each transducer is driven by its own generator (one generator to one transducer)?

We bought the Russian model that has 2 transducers on one generator.  They also made a 1 & 1 model.

Russians are probably applying magnetostrictive transducers?

Do not know what technology they employ but can tell you that the head of each transducer is very heavy, so it must contain a lot of steel.

 

The header plate on the heat exchanger is 31.75 mm thick steel plate to which we welded nuts and then screwed the transducers into the nuts. 

 

If the screwing is an acceptable fixating method for you, we can realize something similar with my transducers.  There are other methods how I can fix my transducers…. We will analyze what would be the best.

There seems to be a lot of weight cantilevered on the end of the transducer, but the fixing nut and weld is relatively small.  I am a little concerned about whether there will be a cyclic stress in the weld which may eventually cause it to fail.  A bigger nut outer diameter may help relieve this, but we would consider other attachment methods if you recommend any.

 

 We have some jobs that will require units in 208V 60 Hz and other that are 460V 60 Hz, where these are phase to phase voltages and the phase to ground/neutral voltages are 120V and 277V respectively.

 

MPI generators are operating from 208 until 230 VAC 50/60 Hz, between two phases in US.  Until present we did not make ultrasonic generators that are operating on 460 VAC.

We can use step down transformers to convert the 460 to 208 V..

 

 Can you give me an indication of your price to treat one heat exchanger, bearing in mind that we will have at least 5 more to do.

 

I am not sure if I could give lower prices compared to Russian products (since MPI is operating in Switzerland… where everything is more expensive to produce…).  Anyway, I will do my best.  Please first send answers on my questions from this email, and later I will have a better picture regarding what to propose.

 

Regards,

 

Miodrag

 

 

Regards,

 

 

 

Chris,

 

Could you send me photos after you installed Russian transducers?  We can make simpler installation of MPI transducers.

 

Regards,

 

Miodrag

 

 

 

Sorry,

 

Photos attached now.  These were taken before we fitted the four transducers to one heat exchanger.

 

 

 

Please attach again the photo of the plate and frame heat exchanger (attachment not received).

 

We can very successfully vibrate ultrasonically your heat exchangers.  We already have good experience…

 

We also applied ultrasonic vibrations on cleaning water pipelines in nuclear power plant for removing buildups…

 

I am sure that we will be able to help you.

 

Regards,

 

M. Prokic

 

 

 

Dear Sirs,

 

We have several applications where we need to prevent the growth of iron related bacteria in plate and frame heat exchangers that use salty well water to cool fresh water in air conditioning applications.  We have already successfully applied this technology from a company in Russia whose web link is as follows?- http://www.zevs.ru/eng_zevsonic.phtml  I have also attached a photo of the plate and frame heat exchanger that we successfully fitted these units to.

 

Unfortunately we are no longer able to contact the Russian company, so we believe they may have gone out of business.  Do you have any experience in this type of ultrasonic application, and if so are you able to provide a quote on the system we need for more heat exchangers if we send you their dimensions etc.?

 

Regards,

 

Chris Nash, P. Eng.

Engineering Manager & Acting Service Manager

BAC

Tel. (441) 278 6225

Cel. (441) 537 0824

Fax. (441) 292 6887