Puppeteer

Author Topic: Ultrasonics  (Read 685 times)

snowman18

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Ultrasonics
« on: November 10, 2019, 07:43:11 AM »
I built a five gallon tank with four 25mhz transducers that I use to recover precious metals from catalytic converters.

I'm far  from being the brightest light in the string and often find myself being the victim of an experiment gone wrong.

In the beginning of this great adventure decided to add dish detergent to break the surface tension of the water to prevent float.

Aside from ending up with more foam than I had containers for the foam did work similar to a process called froth flotation.

As you can see to some degree I've discovered the magic of ultrasonics and would like to expand my knowledge of its use.

gort has me working overtime on this wet oil, and started doing some research when I came across this interesting peace

Full article and credits, https://www.e-sciencecentral.org/articles/SC000015241

Research Articles

Journal of Biosystems Engineering 2012; 37(6): 429-433.

DOI: https://doi.org/10.5307/JBE.2012.37.6.433
Viscosity Characteristics of Waste Cooking Oil with Ultrasonic Energy Irradiation
Tae Han Kim*, Jung Keun Han

Department of bio-industrial machinery Engineering, Kyungpook National University, Daegu, Korea

*Tae Han Kim Tel: +82-53-950-5793; Fax: +82-53-950-6780 E-mail: thakim@kun.ac.kr
Received 15 October 2012       Revised 16 December 2012       Accepted 31 December 2012

Copyright 2012, Korean Society for Agricultural Machinery

(open-access, http://creativecommons.org/licenses/by-nc/3.0/):

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.


Abstract


Purpose:
While rapeseed oil, soy bean oil, palm oil and waste cooking oil are being used for biodiesel, the viscosity of them should be lowered for fuel. The most widely used method of decreasing the viscosity of vegetable oil is to convert the vegetable oil into fatty acid methyl ester but is too expensive. This experiment uses ultrasonic energy, instead of converting the vegetable oil into fatty acid methyl ester, to lower the viscosity of the waste cooking oil.
Methods:

For irradiation treatment, the sample in a beaker was irradiated with ultrasonic energy and the viscosity and temperature were measured with a viscometer. For heating treatment, the sample in a beaker was heated and the viscosity and temperature were measured with a viscometer. Kinematic viscosity was calculated by dividing absolute viscosity with density.
Results:

The kinematic viscosity of waste cooking oil and cooking oil are up to ten times as high as that of light oil at room temperature. However, the difference of two types of oil decreased by four times as the temperature increased over 83℃. When the viscosity by the treatment of ultrasonic energy irradiation was compared to one by the heating treatment to the waste cooking oil, the viscosity by the treatment of ultrasonic energy irradiation was lower by maximum of 22% and minimum of 12%, than one by the heating treatment.

Conclusions:
Ultrasonic energy irradiation lowered the viscosity more than the heating treatment did, and ultrasonic energy irradiation has an enormous effect on fuel reforming.

Go to : Goto

Keywords: Waste cooking oil, Viscosity characteristics, Ultrasonic energy, Heating, Density

Introduction

Recently biodiesel has been receiving increasing attention as an alternative fuel due to the finiteness of fossil fuel and reduction of greenhouse gas. Biodiesel contains 8.5~11% oxygen and it is expected to reduce the harmful gas from diesel engine (Nishino et al., 2009). Biodiesel raw materials vary according to the countries; for example, European countries use the rapeseed oil, USA uses the soybean oil, Southeast Asian countries use the Palm oil, and Japan uses the waste cooking oil. Germany, France and Italy occupy the majority of worldwide biodiesel production (1,800,000 kL) (Nishijaki, 2006).

Waste cooking oil should be processed to lower the viscosity to use as diesel fuel. The high viscosity of the vegetable oil causes incomplete combustion in a combustion chamber and hinders the engine operation. Transformation of fatty acid into methyl ester is the most widely used technology to lower the viscosity of vegetable oil. The technology is safe and commercialized because it make mass production possible. However, it has several disadvantages: it cannot be applied to a small device, it needs a process to remove water and free fatty acids in raw materials, and it costs a lot to purify glycerin, which is a by-product of esterification.

For these reasons, a non-catalytic biodiesel production route with supercritical methanol has been developed to purify the vegetable oil. The new technology produces a single layered liquid without glycerin. However, the technology needs manufacturing equipment such as anticorrosive reactor, high-pressure pump, back pressure pump, and heat exchanger (Iljima et al., 2008). In Korea, there are lots of research on the experiment of agricultural engines using biodiesel which was processed by esterification with soybean oil (Choi and Oh, 2010) and rapeseed oil (Choi and Byeon, 2009).

However, there is little research on biodiesel for agricultural engines without esterification in waste cooking oil. According to Chung and Park (2010), using ultrasonic energy irradiation in transesterification made reaction faster and acid value lower over 30%. In addition, Im et al. (2007) reported that ultrasonic energy irradiation to biodiesel blended fuel lower the viscosity. The result, however, was not clear if the viscosity was lowered due to the ultrasonic irradiation or heating treatment of raw materials. Thus, this study will compare the viscosity changes of ultrasonic irradiation and heating treatment which are used for lowering viscosity without esterification in waste cooking oil.

Materials and Methods

The viscosity of sample was measured using Brookfield Viscometer (LVDV-II+Pro. Brookfield Engineering Laboratory, USA) as shown in Figure 1. After the sample in a beaker was heated, the absolute viscosity and temperature were measured using viscometer. For density calculation, the volume and weight were measured while heating the sample in a measuring cylinder. Kinematic viscosity was calculated by dividing absolute viscosity by density.
ksam-37-429-g001.tif   

Figure 1.
Brookfield viscometer.

Download Figure
Figure 2 shows the ultrasonic generator (VCX750, Sonic and Material Inc. USA). The ultrasonic generator creates high frequency electric energy with 230V of the source of electric power. The voltage creates 20,000 sparks per second to the piezoelectric crystal and the crystal transforms into mechanical vibration with 20,000 expansion and contraction per second. The vibration is amplified by the probe and transmitted to the sample. The converter has four piezoelectric crystals. The ultrasonic wave generator digitally displays the actual amount of energy in joules (or watts) that is being delivered to the probe. The sample in a beaker was irradiated with ultrasonic energy, and its viscosity was measured with the viscometer. One can choose the amount of ultrasonic energy irradiation being delivered to the probe between 150 W to 750 W. The amount of ultrasonic energy irradiation was set at 600 W for this experiment.
ksam-37-429-g002.tif   
Figure 2.
Schematic diagram of ultrasonic generator.

Download Figure
Table 1 shows the specification of ultrasonic generator. The amplitude of the probe is 35 ㎛, diameter and length are 19 mm, 136 mm respectively.
Table 1.
Specification of ultrasonic generator
Probe Dia. Length (mm)    19 136
Prove Type    Solid
Amplitude of probe tip (μm)    61
Convertor Dia. Length (mm)    63.5 183
Capacity (㎖)    10 to 250
Ultrasonic irradiation energy (W)    150 to750

Download TableDownload Table
The ceramic heater (MS400, BANTE, Chicago, USA), a heating device which can control the temperature of samples within the beaker, was used to heat the waste cooking oil. The temperature of samples within the beaker was measured with the thermocouple. The materials used in the experiment included waste cooking oil, cooking oil, light oil, and blended oil.
BD20, 40, 60, and 80 mean the light oil is blended with waste cooking oil with 20, 40, 60, and 80% v volume ratio respectively. BD0 means 100% light oil, and BD100 means 100% waste cooking oil. Waste cooking oil was filtered once with No. 500 wire-mesh.
Results and Discussion
Figure 3 shows the density of waste cooking oil, cooking oil, and light oil. Waste cooking oil was filtered once with No. 500 wire-mesh. As in the figure below, waste cooking oil and cooking oil showed 10% higher density compared to the density of light oil. Furthermore, the densities of three types of oil decreased as temperature increased.
ksam-37-429-g003.tif   
Figure 3.
Relation between temperature and density of various oils.

Download Figure
Figure 4 shows the kinematic viscosity of waste cooking oil, cooking oil, and light oil. The kinematic viscosity of waste cooking oil and cooking oil were up to ten times as high as that of light oil at room temperature. However, the differences of kinematic viscosity in two types of oil reduced four times as the temperature increased above 70℃. This indicates that waste cooking oil should be heated for fuel used in agricultural engines without esterification. In addition, the kinematic viscosity of filtered waste cooking oil was 10% higher than that of cooking oil at room temperature, but the differences decreased with increasing temperature and became the same value above 45℃.
ksam-37-429-g004.tif   
Figure 4.
Relation between temperature and kinematic viscosity of various oils.

Download Figure
Figure 5 shows the kinematic viscosity of light oil after the ultrasonic energy irradiation and heating treatment. As shown in Figure 5, there was no difference in kinematic viscosity between ultrasonic energy irradiation and heating below 50℃, but above the 50℃ viscosity of ultrasonic energy irradiation was 5~6% lowered than that of heating. It indicates that ultrasonic energy irradiation lowered the viscosity. This is caused by ultrasonic cavitation.
ksam-37-429-g005.tif   
Figure 5.
Effect of ultrasonic energy irradiation on viscosity for light oil.

Download Figure
When ultrasonic wave is irradiated in the solution, the solution periodically repeats compression and expansion. In this expansion, micro-bubbles are formed in the solution. When these bubbles are compressed over the surface force, the solution immediately shrinks, explodes, and produces shockwaves. Because of these shockwaves, the solution disperses and decomposes, accompanied by high pressure and temperature. This is called phenomena of ultrasonic cavitation. The viscosity of oils decreases caused by ultrasonic cavitation.
The ultrasonic waves generate acceleration of particles of medium and collapse the dissolved air molecule in the fluids, and the decrease in viscosity of various oils is caused by ultrasonic cavitation.
Figure 6 shows the kinematic viscosity after the ultrasonic energy irradiation and heating treatment in the light oil blended with waste cooking oil with 60% of volume ratio (BD60). As shown in Figure 6, the ultrasonic energy irradiation lowered the kinematic viscosity 21% the maximum and 9% the minimum. Compared with the results in Figure 4, ultrasonic energy irradiation lowered the viscosity of the blended oil (BD60) than the light oil. This shows that ultrasonic cavitation is occurring more actively in blended oil than in light oil.
ksam-37-429-g006.tif   
Figure 6.
Effect of ultrasonic energy irradiation on viscosity for BD60.

Download Figure
Figure 7 shows the kinematic viscosity after the ultrasonic energy irradiation and heating treatment in waste cooking oil. As shown in Figure 7, when the viscosity by the treatment of ultrasonic energy irradiation was compared to one by the heating treatment to the waste cooking oil, the viscosity by the treatment of ultrasonic energy irradiation was lower by maximum of 22% and minimum of 12%, than one by the heating treatment. This shows that ultrasonic energy irradiation of waste cooking oil yields a greater decrease in viscosity than heating treatment of waste cooking oil. This is caused by ultrasonic cavitation.
ksam-37-429-g007.tif   
Figure 7.
Effect of ultrasonic energy irradiation on viscosity for wasted cooking oil.

Download Figure
Figure 8 shows the viscosity changes of waste cooking oil in relation to the ultrasonic energy irradiation time. The kinematic viscosity decreased until 10 minute ultrasonic energy irradiation, and it became stable. Thus it is optimal to irradiate waste cooking oil for 10 minutes.
ksam-37-429-g008.tif   
Figure 8.
Relation between ultrasonic energy irradiation time and kinematic viscosity of wasted cooking oils.

Download Figure
After performing ultrasonic energy irradiation for ten minutes, the temperature of the waste cooking oil is 83℃.
Figure 9 shows the kinematic viscosity of waste cooking oil, blended oil with light oil and waste cooking oil, and light oil according to the ultrasonic energy irradiation time. When the mixing ratio of waste cooking oil was low, the viscosity became low and similar to the viscosity of light oil. Before ultrasonic energy irradiation, the kinematic viscosity of BD100, 80, 60, 40, 20, 0 were 137.6 cSt, 39.7 cSt, 23.0 cSt, 13.9 cSt, 7.3 cSt, 5.2 cSt respectively. However, after ultrasonic energy irradiation, they became 7.8 cSt, 5.5 cSt, 4.0 cSt, 2.8 cSt, 2.0 cSt, 1.8 cSt respectively, and their decreasing ratio were 94%, 86%, 82%, 80%, 73%, 65%.
ksam-37-429-g009.tif   
Figure 9.
Effect of ultrasonic energy irradiation on viscosity for various blended oils.

Download Figure
Conclusions
Biodiesel has similar characteristics with light oil. Because it contains oxygen, it can control emissions. For the fuel injected into the combustion chamber of the diesel engine to combust completely, atomization has to be favorable. This atomizing ability is optimum when viscosity is low. However, since vegetable oil has high viscosity, its viscosity must be decreased for it to be used as a diesel fuel. This study examined the viscosity changes of ultrasonic irradiation and heating treatment which are used for lowering viscosity without esterification in waste cooking oil.
The kinematic viscosity of waste cooking oil and cooking oil were higher than that of light oil by 10 times the maximum at room temperature. However, the differences of kinematic viscosity in two types of oil reduced four times as the temperature increased above 70℃. In addition, the kinematic viscosity of filtered waste cooking oil was 10% higher than that of cooking oil at room temperature, but the differences decreased with increasing temperature and became the same value above 45℃. The ultrasonic energy irradiation lowered the kinematic viscosity 22% the maximum and 12% the minimum than heating treatment. The ultrasonic energy irradiation lowered the kinematic viscosity 21% the maximum and 9% the minimum in the light oil blended with waste cooking oil with 60% volume ration (BD60). 10 minute irradiation was optimal for waste cooking oil. 10 minute irradiation to the blended oil of BD 100, 80, 60, 40, 20, 0 reduced the kinematic viscosity 94%, 86%, 82%, 80%, 73%, 65% respectively.
Conflict of Interest
No potential conflict of interest relevant to this article was reported.
ACKNOWLEDGMENTS
This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2011-00065).
References
1. H. Choi J. W. Byeon . Combustion Characteristics of a Direct Injection Agricultural Diesel Engine with Rapeseed Oil. Journal of Biosystems Engineering. 2009; 34(3):135139. (In Korean, with English abstract). DOI: 10.5307/JBE.2009.34.3.135.
[CrossRef] [Google Scholar]
2. S. H. Choi Y. T. Oh . A Study on Engine performance and Exhaust Emission for Biodiesel lending Ratios and Fuel Injection Timing in an Indirect Injection Compression Ignition Engine. Journal of Biosystems Engineering. 2010; 35(4):239243. (In Korean, with English abstract). DOI: 10.5307/JBE.2010.35.4.239.
[ScienceCentral] [CrossRef] [Google Scholar]
3. K. H Chung B.G. Park . Biodiesel Production from Vegetable Oils by Transesterification Using Ultrasonic Irradiation. Appl. Chem. Eng. 2010; 21(4):385390. (In Korean, with English abstract).
[Google Scholar]
4. W. Iljima Y. Kobayash K. Taniwaki . Development of New Technology for Alternative diesel Fuel Production Involving Simultaneous Application of Methanolysis and Thermal Cracking (Part 1). Journal of JSAM. 2008; 70(2):120126. (In Japanese, with English abstract).
[Google Scholar]
5. S.Y. Im Y. S. Song Y. C. Jung D.S. Choi J.I. Ryu . An Experimental Study on Physical and Chemical Characteristics with Biodiesel blended Fuel According to Ultrasonic Energy Irradiation Time. In : Proceeding of KSAE 2007 Spring Conference; 2007; 539546. (In Korean, with English abstract).
6. K. Nishijaki . The Use of Biofuel for Agricultural Machinery. Journal of JSAM. 2006; 68(2):48. (In Japanese, with English abstract).
[Google Scholar]
7. K Nishino. Y. Miyata Y. Shibuya N. Noguchi . Application to Small-sized Diesel Engine of Biodiesel Fuel Generated from Rapeseed Oil. Journal of JSAM. 2009; 71(5):8894. (In Japanese, with English abstract).
[Google Scholar]
Formats:
Article |
PDF LinksPDF(790K) | PubReaderPubReader | EpubePub |
Download Citation
Share  |
     [Facebook]   [Twitter]   [LinkedIn]   [Google+]
METRICS    
1,086
View
   
33
Save
0
Cited-By
   
In This Page:
ABSTRACT
Related articles in ScienceCentral:
Investigation of Centrifugal Rice Seeder for Unmanned Helicopter
[J. of Biosystems Eng.. 2012]
Evaluation of Spray Flight Attitude for Agricultural Roll-balanced Helicopter using Kalman Filter
[J. of Biosystems Eng.. 2012]
Development of an Inexpensive Black Box with Transmission of SOS and Theft Signal for an Agricultural Tractor
[J. of Biosystems Eng.. 2012]
Development of Vibration Absorption Device for the Transportation -Trailer System (IV)
[J. of Biosystems Eng.. 2012]
Study on the Treatment Performance of SCB-M with Swine Manure
[J. of Biosystems Eng.. 2012]
.

« Last Edit: November 10, 2019, 07:44:50 AM by snowman18 »

snowman18

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Ultrasonics
« Reply #1 on: November 10, 2019, 07:54:04 AM »
This was undesired,

As the foam collapses a layer of scum becomes visible, that scum contains precious metals. Rather than dealing with a several cubic yards of foam these metals could be collected at the filter.




cobbadog

  • Sr. Member
  • ****
  • Posts: 268
    • View Profile
Re: Ultrasonics
« Reply #2 on: December 10, 2019, 05:06:53 AM »
Now that you are back on this topic of ultrasonics I have an industrial one in the shed I use for cleaning blinds, thats my bussiness. There is 2 ways of minimising or getting rid of the foam and the simpleast is to add vinegar, yep vinegar. This kills the suds or it does in another old blind cleaning machine.
If that is not good enough go to your local chemical supplier and buy a low suds or a detergent suitable for use in a ultrasonic machine. They may well have a customer who buys a detergent off them that does the job. I buy mine through Venture Chemicals in Sydney as I like that product for what I do but a local chemical supplier has been wanting me to ry his chemicals which come from a factory in Newcastle NSW but that name escapes me now but may have been Hammersley or that one over near Stockton that keeps getting fined by the EPA for ammonia spills.
Coopernook - the centre of our Universe.

oldgoat

  • Full Member
  • ***
  • Posts: 137
    • View Profile
Re: Ultrasonics
« Reply #3 on: December 10, 2019, 01:42:37 PM »
When i used to drill with foam I woud use Bariod Baradefoam 500 toget rid of the bubbles and cuttings. It worked really well just spraying it over the top in the mud pit. For the foam i used Ultrafoam by the same company and when mixed thick enough it would lift coarse sand up the annulus in the foam.

glort

  • Hero Member
  • *****
  • Posts: 3185
    • View Profile
Re: Ultrasonics
« Reply #4 on: December 11, 2019, 06:44:51 AM »

I read the first few lines of the article and Skimmed the rest.
How can I summarise this piece?  A complete and utter load of bollocks written by clueless twits would come close.

So much in there that is wrong.  Even in the first line, the viscosity of oils should be lowered.  I'll bet my backside whoever wrote that couldn't tell you why or even knew that they don't have to be lowered at all. This piece was clearly written by people with Zero knowledge of practical use of veg fuels and were starting off basing their work on parroted mantra's which are in fact false. 

It goes on comparing centistrokes of blended fuel and then heated oil but makes no reference to the CT rating of various injector pumps and to clarify if the oil in fact needed thinning in the first place. They also omitted that if after Blending, heating and Buzzing it was within the parameters of the various types of pumps out there and was therefore suitable for use in them or not.  I could lower the viscosity of Oil by  27% in various ways but that's irrelevant to whether Its fit for use in a Common rail Diesel engine.

 The language is so poor I wasn't even sure what they were saying in multiple parts even after reading several times. The terms they use are confusing and certainly not what is used in the industry/ interest.

I find this statement to be HIGHLY suspect:

" Before ultrasonic energy irradiation, the kinematic viscosity of BD100, 80, 60, 40, 20, 0 were 137.6 cSt, 39.7 cSt, 23.0 cSt, 13.9 cSt, 7.3 cSt, 5.2 cSt respectively. However, after ultrasonic energy irradiation, they became 7.8 cSt, 5.5 cSt, 4.0 cSt, 2.8 cSt, 2.0 cSt, 1.8 cSt respectively, and their decreasing ratio were 94%, 86%, 82%, 80%, 73%, 65%."

In BD they are not talking about Biodiesel but in fact used blended oil. These terms are completely arse about to what everyone else uses.
If they are talking about Pure Biodiesel with a CT of 137, it must have been frozen.
In any case, If they got the viscosity of whatever it was from 137 to to 7.8 with what I can gather is 10 Min Ultrasonic treatment, I'd say that's a world stopping break through.
That would mean you could take used cooking oil, give it a buzz and it would be suitable to run thought any modern diesel system out there.

I don't think so Tim!

By all means give this a try. You won't need any fancy equipment to see the difference.  Just punch a Small hole in a Disposable cup and Time the oil running through it into another cup to a marked qty and repeat after buzzing it.  With the difference in viscosity  they claim it produces, Should be like  thickened cream and water.

I'm afraid until someone can test and confirm these results, I'll put them well and truly into the " Too good to be true" basket especially in the absence of what  chemical properties of the oil changed such as where the Trigs went or what happened to them to allow such a huge CT change to take place and all the other questionable aspects of the article. 


cobbadog

  • Sr. Member
  • ****
  • Posts: 268
    • View Profile
Re: Ultrasonics
« Reply #5 on: December 11, 2019, 10:26:35 AM »
And here I was thinking that this thread was on ultrasonics not this dribble. There is another thread running at the moment for those interested in that.
Coopernook - the centre of our Universe.

snowman18

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Ultrasonics
« Reply #6 on: December 11, 2019, 03:22:08 PM »
I'm just a hobbyist trying new methods to reclaim precious metals without the use of chemicals and just recently started experimenting with ultrasonic transducers.

The scum in the foam is palladium which at today's spot price is worth $1894.00 US a troy ounce this is what pays for my toys and parts needed to rebuild them.

What I found interesting is the amount of suds produced from sonification anyhow from research I've found that ultrasonic's has a role in a lot of places in industry.

For my purposes ultrasonics works, assay report from the experiment.






glort

  • Hero Member
  • *****
  • Posts: 3185
    • View Profile
Re: Ultrasonics
« Reply #7 on: December 12, 2019, 12:09:41 AM »

As you have the equipment and Knowledge, I'd like to see some experiments done on oil with regards to lowering viscosity.  I have no idea what would be needed, the power of the transducers or anything else.  It would be good to know if they can change the viscosity of the oil and if so by how much?

snowman18

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Ultrasonics
« Reply #8 on: December 12, 2019, 03:29:44 AM »

As you have the equipment and Knowledge, I'd like to see some experiments done on oil with regards to lowering viscosity.  I have no idea what would be needed, the power of the transducers or anything else.  It would be good to know if they can change the viscosity of the oil and if so by how much?

You give too much credit in regards to knowledge, just a retired country boy with to much time on his hands.

Transducers are available in various frequencies for instance a 28mhz is audible to human hearing, I'm hearing impaired and have to out my ear directly placed onto the tank then only hear a slight hum.

 28khz in terms of ultrasonics creates very large bubbles, when these bubbles implode a shock wave is created.

28khz is not recommended for cleaning tanks used on metals such as aluminum, zinc die cast etc, the larger cavitation bubbles will actually damage the parts being cleaned.

I had some reservations using the more aggressive 28khz transducers as the ceramic comb used in a catalytic converter compared to metal is a soft material.

This led me to think acoustic tiles used in a recording studio sound room and that theory paid off the ceramics absorbed the acoustics that could otherwise have damaged the ceramic comb adding unwanted trash to the concentrated I was after.

A lot of research goes into developing a propeller for submarine use that will reduce cavitation thus making the sub more stealthy. https://tinyurl.com/u4w7low

Cleaning tanks use transducers in the 35/40khz range that produce a much smaller cavitation bubble a transducer operating in this range is not audible to human hearing and is more gentle on the parts being cleaned.

Some examples of transducers used on soft tissue in the medical field.

Medical ultrasound transducers contain more than one operating frequency. The following frequencies are a guide to frequencies typically used for ultrasound examination:

    2.5 MHz: deep abdomen, obstetric and gynecological imaging
    3.5 MHz: general abdomen, obstetric and gynecological imaging
    5.0 MHz: vascular, breast, pelvic imaging
    7.5 MHz: breast, thyroid
    10.0 MHz: breast, thyroid, superficial veins, superficial masses, musculoskeletal imaging.

I do not heat my shop so there's noting going on at the moment, plenty of videos on your tube, keywords ultrasonic, canola oil, bio diesel, emulsification, homogenization, cavitation and sonification.

It a very long but interesting journey.

And don't forget to use google scholar from some interesting searches this will give you access to many articles from higher education institutions.

« Last Edit: December 12, 2019, 02:07:36 PM by snowman18 »

cobbadog

  • Sr. Member
  • ****
  • Posts: 268
    • View Profile
Re: Ultrasonics
« Reply #9 on: December 12, 2019, 05:34:53 AM »
Heating my tank before use makes it far more effective. When I first set it up after changing the water and detergent solution I must run it for around 10 minutes to, in their words, "de gas" the solution.
My transducers run at 36.7kHz and can also be switched into a 'sweep' mode where as the frequency varies up and down so not to form any 'dead spots' in the tank.
One very effective way to test your transducer is so simple. Switch the system on and have it running. Then dip a strip of aluminium foil in the tank for about 10 seconds and pull it out. You should have perforations through the foil.

WARNING, never put your hand in the tank when switched on is what my instructions say. Now that is like waving a red flag at a bull, why do they say this?
Answer is because apart from killing your flesh if left in too long it also bites like grabbing a HT lead on a good strong magneto, it hurts, I know.
Coopernook - the centre of our Universe.

mike90045

  • Mendocino Metro
  • Hero Member
  • *****
  • Posts: 1451
  • Mmmm BBQ
    • View Profile
    • Mikes Solar PV page
Re: Ultrasonics
« Reply #10 on: December 12, 2019, 07:11:58 AM »
Mhz frequencies are radio waves.  There is no "transducer" unless it's a channel crystal in a holder or a SAW filter

Khz frequencies are closer to Audio, with 20hz - 20Khz being typical Hi-Fi gear, 25Khz generally being the lower end of the ultrasonic range, and a couple Mhz being the upper end.   AM radio roughly covers 0.5Mhz to 2Mhz, above 2Mhz, you are in shortwave radio.

cobbadog

  • Sr. Member
  • ****
  • Posts: 268
    • View Profile
Re: Ultrasonics
« Reply #11 on: December 12, 2019, 10:15:00 AM »
I went looking for the schematics on my machine. It does have 2 very heavy transducers that sit on the bottom of my tank and are connected to 2 generators that sit on the shelf via a metal braided cable.
Coopernook - the centre of our Universe.

glort

  • Hero Member
  • *****
  • Posts: 3185
    • View Profile
Re: Ultrasonics
« Reply #12 on: December 12, 2019, 12:37:13 PM »
I went looking for the schematics on my machine. It does have 2 very heavy transducers that sit on the bottom of my tank and are connected to 2 generators that sit on the shelf via a metal braided cable.

Can you put some used veg oil in it, give it a buzz and let us know if the oil comes out thinner?


 ;D

snowman18

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Ultrasonics
« Reply #13 on: December 12, 2019, 01:56:34 PM »
The Effect of Ultrasonic Waves on Oil Viscosity

This study presents the development of a technique to directly investigate the effect of ultrasonic waves at 25 and 68 kHz and 100, 250, and 500 W on the viscosity of paraffin, synthetic oil, and kerosene.

Experiments were performed under both controlled and uncontrolled temperature conditions in a smooth capillary tube.

The results indicate that the viscosity of the liquids decreases upon exposure to ultrasound and may be attributed to induced heat generation and cavitation within the fluid.

The specifics of ultrasound frequency, power, and temperature on viscosity reduction are discussed and interpreted.

snowman18

  • Full Member
  • ***
  • Posts: 108
    • View Profile
Re: Ultrasonics
« Reply #14 on: December 12, 2019, 02:29:04 PM »
Mhz frequencies are radio waves.  There is no "transducer" unless it's a channel crystal in a holder or a SAW filter

Khz frequencies are closer to Audio, with 20hz - 20Khz being typical Hi-Fi gear, 25Khz generally being the lower end of the ultrasonic range, and a couple Mhz being the upper end.   AM radio roughly covers 0.5Mhz to 2Mhz, above 2Mhz, you are in shortwave radio.


Ultrasonic transducers with an output in from 28/100 khz range are low frequency, mhz are classified as ultra high frequency upwards to the ghz range.

Ultrasonic transducers produce acoustic sound waves via cavitation, bats use echolocation to navigate.

Burning  Water With Radio Waves.

In this video the experimenter is using radio waves to break water down into hydrogen and oxygen to produce fuel.

https://youtu.be/e8utkoK2DhA

https://dnr.maryland.gov/wildlife/Pages/plants_wildlife/bats/batelocu.aspx

About 70% of all bat species worldwide have this ability. Also, bats aren't the only animals that use echolocation. Whales, dolphins, porpoises, oilbirds and several species of shrews, tenrecs, and swiftlets use a similar technique.

Most bat echolocation occurs beyond the range of human hearing. Humans can hear from 20 Hz to 15-20 kHz depending on age. Bat calls can range from 9 kHz to to 200 kHz.
« Last Edit: December 13, 2019, 03:47:14 AM by snowman18 »