Can scanning through Airborne ultrasound be used to set up leak detection program in fertilizer Plant ?

Why not? Ultrasound is sound above the human hearing range. All machines make noise. All compressed air leaks (pressure or vacuum) make noise in the ultrasonic range. If you chose an instrument with "tunable frequency" you may eliminate most background noise. Pressure and or vacuum are best heard in 38-40 kHz range. However, if your instrument does not have tunable frequency adjustments, it may already be "fixed" or centered in the 40 khz range.
........TRY IT YOU'LL LIKE IT!

Can it be used in the fertilizer environment with different gases present not only for compressed air . Is it safe ? What should be the accessories used to improve the productivity ? Doesn't the gases affect the calibration of the sensors.

You will need an IS rated unit. The only instrument out there in the marketplace (I'am aware of) that is IS rated (Intrinsically Safe) for your particular environment would be the Ultraprobe 2000, Class 1, Div. 1, Groups A,B,C,D rated. As far as accessories a long range horn for distance up to 40-50 feet, a close focus module for vacuum or in-leakage (used close-up, up to 18 inches from target). These instruments (UE2000) are not precision instruments, they do not give you cfm's nor CAN THEY and do not get hung-up on using Decibel (dB) to CFM conversion charts.
There is no calibration as such to worry about. You may however use low volume air from time to time to blow off the sensors (piezoelectric crystals) keeping dust or product from building up on the sensors. These instruments register in decibels. NO two instruments will read the same either. Start with one, and use that instrument only if you intend to use these readings to trend data. Even with the contact probes for bearings. Use only the same instrument for your bearing analysis for the contact probes are not calibrated to a known value. You would not want to change a bearing before its time!
There are instruments in the marketplace that are calibrated and have some degree of repeatability. But, they are not IS RATED. (IS..intrinsically safe). Which is what you need for your particular environment.

What all other makes can you suggest which will be effective for surveys other than Ultraprobe 2000 which is based on the analog technology .

Thanks Jim for very good explanation

There is an IS rated ultrasound unit called the SDT 120 that is digital and IS rated but it is not as highly rated for your environment. Other than these two instruments I do not know of any others that are IS rated.
Other NON IS Rated Instruments include:
SDT 170
UE 9000 & 10,0000
CTRL 2000
ACCUTRAK
CSI 7000 & 7100 models (vibration people)

Vedi, Jim has given a very good explanation of the capabilities of airborne ultrasound.

We have a Ultraprobe 2000 unit for almost 6 years now. It is used in oil refinery for detecting leaks, steam, air and if possible gas leaks, although we have experimented other applications as well (no bearing trending).
Radiator cores are one of the favourites, after a repair/service of a unit, we pressure the radiator up with air (10 psi or less) and start inspecting.
It has a warble tone generator, place it in a container and start scanning to detect were the sounds are coming from.
All the excellent remarks about Intrinsically Safe and classes, were our choice for the ultraprobe 2000, we even aquired a special head-phone wich can be used when wearing a hard hat, and the case (comparable to a gun holster), unvaluable when climbing 20 feet of monkey ladders to reach places where "normal people" would not go.

Don't forget to get some vendor neutral expert to train your people.
We bought our unit from an expatriate service company, we paid them for the unit and the training. Looking back, it was worth every cent we spend.

Hi Vedi,

I've used UE9000 before in a Petro-Chemical environment to monitor steam-traps and rotating equipment, with good results; this was some 12 years ago. You have newer gadgets which are IS, these days.
This tool helped prevent MM$ loss in this plant by detecting electro-mechanical fault in a critical AC Motor (2.8MW); when vibration did not indicate a fault.
The only catch is, the operator need to be trained to identify faults. Not just classroom training but, on-site thru' regular use.

Cheers...Rajan

Its not that there is a NEW IS Rated unit. In fact the UP9000 came after the UP2000. Its just with the LED backlight your not going to have an IS rated UP9000 (so I was told by the company some years ago).
Training on-site is what I like to promote to everyone. Training in your environment, using your instrument, your equipment and whats applicable to your applications.
I realize some plants do not have to have IS Rated as they once did. Others however still require the IS Rating.
Great job with the savings. It is pleasing to find that anomalie that vibration did not indicate. There is room in the ol'think tank to use both vibration and ultrasound together. For instance taking your UP9000 and interfacing it with your vibration analyzer.
Good luck......

For testing Steam traps what is the frequency we have to adjust to get the best results. Is this the best tool avaliable for Steam Traps ?

In Airborne Survey how do you cancel other sources of Ultrasound which are nearby.

Thanks everybody for the explantaion

CTRL UL101-RE is also an intrinsically safe device. Center of frequency is 40 kHz, which means the best frequency is 40 kHz for listening to steam traps - and any other application for that matter. No frequency adjustment is required for the UL101.

Thanks everybody for explaining to me the use of Ultrasound in Fertlizers . Ultrasound is effective for Steam Leaks , Steam traps , Compressor Leaks , but can any body tell me what about the overhead pipe lines which we inspect with Parabolic Dish . What are the precautions one has to take as there is so much ultrasound because of the near by pipes . How to cancel the surrounding ultrasound .

Is it effective for detection of leaks through pipe as I found some portion of the pipe although no leaks but lot of ultrasound.

Part One of your question: Boiler leaks, ever go around the burner or boiler area and you see the flame from inside? How big is the opening that you can see the flame. I was in a powerplant recently were I counted about 20 different locations near the Soot Blowers (ninth floor of the plant) were I could see the red hot flame from holes in the casing around wall mounted soot blowers, etc...this is a heat rate problem. There are others I am sure...
NOW PART TWO OF YOUR QUESTION...... A recent reply was made "that tunable frequency is not needed with his particular instrument" because his instrument is tuned to the optimum for leak detection, however when competeing sounds are present that interfere tunable maybe an advantage (key here is "may be"). Optimum range is certainly better in certain noise environments, but in an industrial plant environment I would prefer to have every advantage that one could have to locate a leak without HAVING TO BE PRACTICALLY ONTOP OF THE LEAK TO HEAR IT...... Fixed band on an instrument is a range, sometimes a very wide band range of centered at 40 khz plus or minus 2,8,or 10kHz (depending on the manufacturer). An instrument set at Optimum is typcially centered at 38 or 40 kHz plus or minus 2 kHz. I have used every ultrasonic instrument and parabolic instrument in industry from shoulder mounted rifle type, one hand 10"-18" parabolic reflector, plastic and metal. It is my opinion that the unit that is able to "fine" tune in-or-out as an edge over the others. For instance the SDT 170 MD when using the freqeuncy tuning otherwise none as "Discover Frequency Band" (in the MENU mode) you use the up anddown arrows to tune the instrument, when you select Discover Frequency Band the instrument immediately goes to 38.4 kHz which is optimum frequency for air leak detection, if you press the UP and Down arrows you can select up to 190 kHz (not much up there) or down to audible low-frequency range of 15.1 kHz in .01-.02 kHz increments! This is fine tuning and is extremely effective to tuning into the leak. Fertilizer plants to power plants have so many different sounds (noise) that you may need this function. However, if you have to dance with the partner you brought to the dance (your instrument) you may or may not have tuneable frequency. Therefore you may have to use the surrounding structures, cardboard, or position yourself and the parabolic so as to limit the amount of sound that is collected onto the parabolic surface......ALSO SEE UPTIME MAGAZINE ARTICLE I WROTE ON PARABOLICS NOV. '06.....and you may want to consider using the parabolic horn or Long Distance Horn (SDT) or Long Range Horn (U.E. Systems) instead of the large parabolic dish. A good practice to use when scanning overhead pipe racks that are running parallel with the floor is for you to aim the sensor to the floor. Sounds travel and sometimes I am able to hear the leak from the overhead on the floor in front of me directly below the pipe racks.

So whether we should move up above 40 Khz to cancel surrounding ultrasound , what frequency have you tried and also whether to set the sensitivity at maximum at the starting. So what I could understand we have to play with both sensitivity and frequency to cancel the surrounding Ultrasound .

Whether we should do scanning down below the pipe or from surrounding the pipe at some distance .

Whether to take into consideration the air direction while scanning.

Sorry for the translation. NO you do not have to adjust the frequency above 40kHz. Depending upon what instrument you have........
If you have SDT 170 it is preset at 38.4kHz which is optimum for air leaks. However you may change the mode of operation to "Discover Frequency Band" and adjust the frequency up or down slightly either a few tenths of a kHz or 1-2 kHz.
If you have a UE 2000..come out of "Fixed Band" (centered at 40 kHz) and adjust frequency from 38-40kHz. This instrument does not use a "precise" adjustment knob it is very gross adjustment.
If you are using a UE 9000 or 10000...adjust the frequency from 37 to 42 khz listening for the best sound in the headphones, tuning into the sharpest or peak response.
If you are the Csi 7000 model you can change the instrument to an air leak mode of operation for optimum range.
WITH ANY OF THESE MENTIONED ABOVE YOU MAY HAVE TO ADJUST IF THE SURROUNDING AMBIENT NOISE IS TOO MUCH TO POSSIBLY ELIMINATE THE COMPETEING SOUNDS.
EVERY other instrument out there does not afford you frequency tuning as such. There are preset to the 38-40 kHz range and you use the same frequency for bearings, steam traps, electrical, etc....
You have had ALL the EXPLANATIONS YOU NEED AT THIS TIME........Now you should preceed to practice with the instrument you have in your environment. I or anyone else are not personally familiar with your particular plant. So GO OUT and get familiar with what you have.
Scan above and below, scan from 50-60 feet away, scan from 20-30 feet away, scan close-up...See what you can expect from the instrument you have.
By the way WHAT ultrasound instrument are you USING????

We are using SDT 170 MD equipment