Ultrasonic Atomizing Nozzle Systems

ULTRASONIC ATOMIZING

NOZZLE SYSTEMS

OPERATING INSTRUCTIONS

Version 1.4

For use with Models 06-5108 and 06-05112

Broadband Ultrasonic Generators

Thank you for selecting a Sono-Tek Ultrasonic Atomizing NozzleSystem. We are confident that this product will provide many years ofreliable service in your application.

We intend to provide you with the highest level of support and servicein order to assure your continued satisfaction. Our corporate philosophyin this regard is expressed best by our Mission Statement:

Sono-Tek is committed to being the world’s leadingsupplier of ultrasonic spray technology products andrelated equipment. We expect to achieve sustainedgrowth and profitability by providing quality andcost effective solutions to the global markets weserve.

Through the skills and dedication of our team,working in an environment where we can all growand prosper, we shall maintain the highest level ofproduct performance and customer satisfaction.

We encourage you to contact our highly qualified staff if you havequestions regarding operation or service. Call us at 845-795-2020, faxus at 845-795-2720, or e-mail us at [email protected]. However, westrongly advise that, before contacting us, you read these OperatingInstructions carefully.

In addition, extensive technical information about our technology,applications, and products is available on our home page located onthe Internet at www.sono-tek.com.

CONTENTS

1. 0 IMPORTANT SAFEGUARDS 5

2.0 INTRODUCTION 7

2.1 ULTRASONIC ATOMIZING NOZZLES --HOW THEY WORK 7

2.2 BROADBAND ULTRASONIC GENERATOR 82.3 BROADBAND ULTRASONIC GENERATOR

SPECIFICATIONS 10

3.0 SYSTEM SET-UP 11

3.1 CONNECTING THE NOZZLE TO A LIQUIDDELIVERY SYSTEM 12

3.1.1 LIQUID DELIVERY SYSTEMRECOMMENDATIONS 12

3.2 NOZZLE MOUNTING RECOMMENDATIONS 133.3 POWER SOURCE REQUIREMENTS 143.4 FREQUENCY SETTINGS FOR THE BROAD-

BAND ULTRASONIC GENERATOR 14

4.0 OPERATING CONSIDERATIONS 17

4.1 LIQUID DELIVERY 174.2 NOZZLE /LIQUID DELIVERY SEQUENCING 214.3 PLUMBING 224.4 NOZZLE POWER SETTINGS 234.5 MAXIMUM FLOW RATE VS. NOZZLE ORIFICE

SIZE AND ATOMIZING SURFACE AREA 254.6 FLOW RATE RANGE 264.7 DROP SIZE DISTRIBUTIONS 26

5.0 OPERATING INSTRUCTIONS 28

5.1 INITIAL START-UP 285.2 EXTERNAL TRIGGER INPUT 305.3 EXTERNAL POWER CONTROL 325.4 ALARM OUTPUT 33

6.0 TROUBLE-SHOOTING CHECKLIST 35

7.0 MAINTENANCE 37

8.0 LIMITED WARRANTY 39

4 Operating Instructions (v 1.4)

SONO TEK

Operating Instructions (v 1.4) 5

SONO TEK

1.0 IMPORTANT SAFEGUARDS

The lightning flash within an equilateral triangle isintended to alert the user to the the presence ofuninsulated “dangerous voltage” within theproduct’s enclosure that may be of sufficientmagnitude to constitute the risk of electrical shock.

The exclamation point within an equilateral triangleis intended to alert the user to the presence ofimportant operating and maintenance instructionscontained in these Operating Instructions.

1. Read Instructions - All the safety and operating instructions shouldbe read before the Sono-Tek Ultrasonic Atomizing Nozzle System isoperated.

2. Retain Instructions - The safety and operating instructions shouldbe retained for future reference.

3. Heed Warnings - All warnings on the ultrasonic nozzle, BroadbandUltrasonic Generator, and other accompanying items should be adheredto.

4. Follow Instructions - All operating and use instructions should befollowed.

5. Attachments and Equipment - Never add any attachments and/orequipment without the approval of the manufacturer as such additionsmay result in the risk of fire, electric shock, or other personal injury.

6. Ventilation - Slots and openings in the Broadband UltrasonicGenerator enclosure are provided for ventilation and to ensure reliableoperation of the system and to protect it from overheating. Do notblock these openings.

7. Power Sources - This Broadband Ultrasonic Generator should beconnected to a power source only of the type described in theOperating Instructions or as marked on the generator.


SONO TEK

8. Object and Liquid Entry - Care should be taken so that objects of anykind are never pushed through or fall through openings in theBroadband Ultrasonic Generator as they may touch dangerous voltagepoints or short-out parts that could result in a fire or electrical shock.Never spill or spray liquid, of any kind, on the Broadband UltrasonicGenerator.

9. Damage Requiring Service - The Ultrasonic Atomizing Nozzle Systemshould be serviced by Sono-Tek qualified service personnel when:

a. Liquids have fallen into the Broadband UltrasonicGenerator; or

b. The Ultrasonic Atomizing Nozzle System does notappear to operate normally or exhibits marked changesin performance; or

c. The Ultrasonic Atomizing Nozzle System does notoperate normally by following the OperatingInstructions; or

d. The ultrasonic nozzle has been damaged through useor by dropping; or

e. The Broadband Ultrasonic Generator has been dropped,or otherwise damaged.

10. Servicing - The user should not attempt to service the UltrasonicAtomizing Nozzle System beyond those means described in theseOperating Instructions. All other servicing should be referred toqualified service personnel.


SONO TEK

2.0 INTRODUCTION

2.1 ULTRASONIC ATOMIZING NOZZLES --HOW THEY WORK

As their name implies, ultrasonic atomizing nozzles are devices that vibrateat frequencies beyond those of human hearing; that is, in excess of 20 kHz.The atomized spray they produce results from the breakup of unstablecapillary waves developed in the liquid introduced onto the rapidlyvibrating atomizing surface of the nozzle. Ultrasonic atomization is solelya surface phenomenon. The amount of liquid atomized depends exclusivelyon the rate at which liquid is introduced onto the surface.

Therefore, in principle, ultrasonic nozzles have infinite variability withrespect to flow rate. Although practical considerations related to nozzledesign limit this variability (typically the achievable ratio of maximum tominimum flow rates is at least 5:1), the ability to precisely adjust flow ratesby adjusting the rate at which liquid is delivered to the nozzle is oftenuseful.

Another major attribute of ultrasonic nozzles, one which distinguishesthese devices from all other atomizing devices, is the low-velocity characterof the spray, typically 0.6 to 1.2 feet per second as compared to 35 to 70feet per second for standard pressure atomizing nozzles. This approximately100-fold reduction in spray velocity is equivalent to a 10,000 times reductionin kinetic energy.

Thus, when the spray is directed toward a target surface to be coated,there is little tendency for the material to bounce off the surface and intothe environment. This so-called overspray or “bounce back” that isnormally associated with pressure nozzles, virtually disappears as a problemwith ultrasonic nozzles.

The physical embodiment of an ultrasonic nozzle generally takes the formof a device such as that shown on the following page. Disc-shapedceramic piezoelectric transducers convert high frequency electrical energyfrom a power generator into vibratory mechanical energy at the samefrequency.


SONO TEK

The transducers are sandwiched between two titanium cylinders, whichact to concentrate and amplify the vibration, maximizing it at the atomizingsurface. Titanium is used because of its good acoustical characteristics,corrosion-resistance and high strength.

The liquid is delivered to the atomizing surface through a large diameterfeed tube that runs the length of the nozzle. The large liquid feed orificeassures freedom from clogging.

2.2 BROADBAND ULTRASONIC GENERATOR

The high frequency electrical energy required by all Sono-Tek spraynozzles is provided by our Broadband Ultrasonic Generator. This versatile,rugged power source offers an array of features that both simplify andenhance the operation of our nozzle systems:

• Operates over a frequency range of 20 - 120 kHz -- exactfrequency is user selectable for any Sono-Tek nozzle

• Uses advanced phase-locked-loop control technology toautomatically lock onto a nozzle’s specific operating frequency

• Regulated output assures that the power delivered to anozzle remains constant

FrontHorn

AtomizingSurface

O-ring Seal

Rear Horn

ElectricalConnector

Liquid Feed Tube

O-ring Seal

Ground Lug

GroundElectrode

Rear Housing

ActiveElectrode

PiezoelectricTransducers

O-Ring Seal

FrontHousing


SONO TEK

• Provides alarms in the event of system malfunction

• LCD power meter and power level control forsetup and monitoring

• Available in two versions: 100 - 240 VAC free-standingsystem and 24 VDC modular system intended for useprimarily in multiple-nozzle rack-mount or OEMconfigurations

• On/off triggering from an external control signal(optional cable required)

• Input for remote power level control(optional cable required)

• Output for connection to a remote malfunction alarm(optional cable required)

ILLUSTRATED ABOVE IS THE FREE-STANDING MODEL P/N 06-05108.THE 24 VDC MODULAR VERSION (P/N 06-05112) HAS THE SAMEFUNCTIONS EXCEPT THERE IS NO ON/OFF SWITCH AND THE ACPOWER RECEPTACLE IS REPLACED BY 24 VDC TERMINATIONS.

90 - 240 VAC50/60 Hz

EXTERNALTRIGGER

EXTERNALPOWERADJUST

ALARMOUTPUT

OUTPUTTO NOZZLE

FRONT

REAR

ULTRASONIC GENERATORI

O

4.6

SONO TEK


SONO TEK

2.3 BROADBAND ULTRASONIC GENERATORSPECIFICATIONS

Free-standing Modular (P/N 06-05108) (P/N 06-05112)

Frequency Range 20 -120 kHz

Output Power 20 W max. intermittent15 W max. continuous

Input Power 90 -260 VAC, 50/60 Hz 23 - 25 VDC, ±5% reg.Requirements

Power 75 VA max. 60 VA max.Consumption

Operating 32 - 105 OF (0 - 40 OC)TemperatureRange

Dimensions 8.5” W x 9” D x 2.25” H 5.25” W x 7.5” D x 2” H (219 x 228 x 57 mm) (133 x 190 x 51 mm)

Weight 4.3 lbs 1.2 lbs (2.0 kg) (0.6 kg)


SONO TEK

3.0 SYSTEM SET-UP

The cable from the generator and the liquid line both must beconnected to the nozzle before turning power ON.

The nozzle housing is sealed. Do not attempt to remove thehousing from the nozzle body since damage may result.

The cable connecting the nozzle to the Broadband UltrasonicGenerator contains a screw-on connector at the nozzle end.Hand tighten this end. Do not use a wrench.

The generator produces heat under normal operation.Therefore it is important to locate the unit so that heat candissipate properly. Do not block any of the ventilation ports.

Do not enclose the generator in a sealed enclosure sinceexcessive heat build-up is possible, which could result infailure.

Do not operate the generator in an environment where thetemperature can exceed 105OF (40OC).

Do not place the nozzle in an environment where the ambienttemperature can exceed 255OF (125OC), and/or where thetemperature of the liquid being atomized exceeds 255OF(125OC). If the application requires operating under conditionswhere these limits may be exceeded, please contact Sono-Tek . We can furnish nozzles that are specially fitted with air/gas cooling ports that allow operation at temperatures beyondthese limits.


SONO TEK

3.1 CONNECTING THE NOZZLE TO A LIQUID DELIVERYSYSTEM

Select liquid delivery tubing with a diameter consistent with the size of theSwagelok® fitting supplied. Plastic tubing is recommended. The type oftubing used must, of course, be chemically compatible with the liquid tobe sprayed. Try to avoid tubing that kinks easily. In applications whereprecise metering of the flow is required or where the flow is turned on/offvery rapidly, avoid tubing that is elastic. Elastic tubing can expand andcontract, making it difficult to control the flow.

Use the compression fitting supplied to attach the liquiddelivery tubing to the nozzle. Do not use any other types offittings. Unsatisfactory nozzle performance may result if othertypes of coupling methods are used. Before attempting touse fittings other than those supplied with the nozzle, pleasecontact Sono-Tek for information regarding compatibility.

When inserting tubing into the fitting, make certain that the fitting issecurely attached . Loose fittings may cause degradation of nozzleperformance and may become quite hot due to the absorption of ultrasonicenergy. The manufacturer recommends that the fitting be turned, using awrench, 1/4-turn beyond finger tight. To avoid rotating the entire fitting,hold the bottom of the fitting with a second wrench when tightening.

3.1.1 LIQUID DELIVERY SYSTEM RECOMMENDATIONS

Choosing the proper liquid delivery system often makes the differencebetween acceptable and unacceptable performance. Sono-Tek’s salesengineering staff will gladly recommend the proper system for yourapplication. If it is more convenient, we can supply you with an appropriatedelivery system. To learn more about optimizing the liquid delivery foryour application, contact us for further information, or visit our technicallyoriented web-site at http://www.sono-tek.com.


SONO TEK

Some guidelines may be helpful. Remember that Sono-Tek nozzle systemsoperate at low pressure. In general, best performance will be obtained ifthe delivery device is capable of giving a uniform steady flow. Gear pumps,syringe pumps, pressurized canisters and gravity feed systems are allcapable of providing steady flow. Peristaltic and piston pumps generallygive a pulsating flow and can give unsatisfactory results unless used witha pulse dampener. Pressure reducing regulators are necessary ininstallations where the source is under high pressure.

In applications requiring very small, but precise volumes of liquid, syringepumps or pressurized canisters are recommended.. For continuous flowapplications, gear pumps are a good choice. Gravity feed systems areuseful only in applications where flow rate precision is not critical, andthen, only when fitted with liquid level controls. (See Section 4.1 for detailsconcerning liquid delivery systems.)

3.2 NOZZLE MOUNTING RECOMMENDATIONS

Sono-Tek nozzles can be operated in any orientation, vertically up, down,or horizontally. The standard method of mounting consists of holding thenozzle with a suitable holding device in contact with the nozzle housing.Special mounting flanges are available from Sono-Tek. Contact our salesdepartment for details. A second, but less desirable mounting techniqueis to clamp on the Swagelok fitting. Using this method may result in a lossin performance and should be used only when the standard method isimpractical.

Do not clamp on any other part of the nozzle except the nozzlehousing or compression fitting. Do not allow other parts ofthe nozzle to come into contact with other structures.

Do not attach heavy components such as valves or flowmeters directly to the nozzle’s fitting or any rigid extensionthereof.


SONO TEK

3.3 POWER SOURCE REQUIREMENTS

For systems supplied with the free-standing, AC version of the BroadbandUltrasonic Generator (p/n 06-05108), the input power requirement is90 - 260 VAC, 50/60 Hz. The line cord provided has the standard U.S.male-end termination. For other terminations, either use an adaptor orcut off the male-end plug and replace with the appropriate plug.

For systems supplied with the 24 VDC version of the BroadbandUltrasonic Generator (p/n 06-05112), the input power requirement is23 - 25 VDC, ±5% regulation. The line cord provided has a two-wiretermination for connection to the 24 VDC power source. White ispositive and black is negative.

3.4 FREQUENCY SETTINGS FOR THE BROADBANDULTRASONIC GENERATOR

All Sono-Tek ultrasonic nozzles are shipped with a tag attached thatspecifies the proper internal dip-switch settings that the BroadbandUltrasonic Generator uses to lock onto a nozzle’s resonant frequency.

The procedure for changing dip-switch settings is straightforward.However, it requires access to the electronic circuitry contained withinthe Broadband Ultrasonic Generator. Please follow all safety procedurescarefully.

In order for an ultrasonic nozzle to function properly, thefollowing instructions must be followed carefully. Improper dip-switch settings will result in the Broadband UltrasonicGenerator being unable to transmit power to the nozzle.


SONO TEK

Dangerous voltages are present in Broadband UltrasonicGenerators supplied with AC voltage (p/n 06-05108).

Before attempting to change dip-switch settings for eithermodel Broadband Ultrasonic Generator, make sure that it isturned OFF and disconnected from its power source. Makingchanges in dip-switch settings while power is applied maynot only provide a risk for electric shock, but also will causedamage to the generator.

1. Locate the 7-position dip-switch assembly on the printed circuitcard,as shown below.

Note: On the free-standing AC model, the cover must be removed.To remove the cover, loosen the four (4) screws that secure the coverand lift off.

2. Note the position of switches 1 through 7 and the location of theword OPEN on the assembly.


SONO TEK

3. Your nozzle may or may not have been shipped with a laminated tagaffixed to the rear fitting. The tag describes the procedure for settingthe dip-switches.

For users in possession of untagged Sono-Tek nozzles (those thatwere in service prior to the introduction of the Broadband UltrasonicGenerator) and are now planning to use this generator, the appropriatetag(s) will be shipped with the unit provided the serial number foryour nozzle(s) was furnished to us when your order was placed.

4. Follow the instructions contained on the tag, a sample of which isreproduced below. Using a pen, pencil, or any another type of pointedobject, depress the individual switches to conform with the punchedhole pattern contained on the tag.

5. Once the proper switch settings have been implemented, theBroadband Ultrasonic Generator is ready for use with that nozzle.

OP

EN

1

7

GENERATOR DIP-SWITCHSETTINGS FOR THIS NOZZLE

DEPRESS EACH OF THE DIPSWITCHES IN THE DIRECTION

SHOWN BY THE PUNCHES BELOW

These settings apply to the nozzle towhich this tag is affixed or to the nozzle forwhich Sono-Tek has supplied the settings.See the Operating Instructions for details.

only

11-00068

leadership

through

innovatio

nsin

ce

1975

SON

OTEK

Corporatio

n


SONO TEK

4.0 OPERATING CONSIDERATIONS

In order to achieve the best performance from your Sono-Tek Ultrasonic Atomizing Nozzle System, we strongly suggestthat you first read this section before attempting to operateyour system. It contains valuable information on manyaspects of system operation. The information provided heremay significantly enhance the outcome in your particularapplication.

4.1 LIQUID DELIVERY

Since ultrasonic nozzles are basically passive devices, that is, they atomizewhatever is delivered to the atomizing surface, the liquid delivery systembecomes a dominant factor in making the process work properly. As aresult, the specifications relating to liquid delivery are a crucial aspect inoverall system design. By virtue of our extensive experience, Sono-Tekcan recommend and provide liquid delivery solutions for virtually anyapplication.

The following discussion of liquid delivery options is meant to serve as abrief guide to the subject. More extensive information is available fromSono-Tek.

There are six (6) basic methods of liquid delivery that are routinely usedwith ultrasonic spray nozzles. These are:

Gear pumpsPiston pumpsSyringe pumpsPressurized canistersGravity systemsPeristaltic pumps


SONO TEK

The principles of operation, auxiliary requirements, and the primarybenefits and limitations of each follow.

Gear Pumps

Principle of operation:

Positive displacement of liquid through meshing gearteeth.

Auxiliary requirements:

Motor speed controller for flow rate variation; positive shut-offvalve.

Primary benefits and limitations:

Mainly for continuous flow; electronically controllable; precise flowrates; not suitable for solids-bearing or non-lubricating liquids.

Piston Pumps


Positive displacement through reciprocating pistonmotion.


Pulse dampener for smoothing flow when used in continuousflow operation.


Can be used for continuous or one-shot operation; wide flow raterange; not suitable for abrasive or non-lubricating materials; requirespulse dampener for continuous flow.


SONO TEK

Syringe Pumps


Slow-moving plunger pushes liquid through a filled syringe.


Depending on application, may require controller with auto-refillcapability and special valving.


Excellent for very small, precise one-shot dispensing; usable withvirtually any material; must be refilled on a regular basis, which mayinterrupt process rhythm.

Pressurized Canisters


Regulated air (or other gas) pressurizes reservoir and forces liquidout at a flow rate determined by the pressure.


Compressed air (or gas); input regulator; shut-off valve on outlet.


Continuous flow or one-shot operation; tolerant of material containingsolids; requires careful choice of line diameters and lengths; notrecommended for flammable materials.

Gravity Systems


Gravity feed with liquid entering a holding tank and regulated on theoutlet by valves; constant level maintained by level sensor and inletvalve.


SONO TEK


Level sensor and control; flow control valve and cut-off valve onoutlet; feed valve on inlet.


Continuous or one-shot operation possible; tolerates solids-bearingmaterials; difficult to maintain reproducibility due to extreme sensitivityto pressure variations, line orientation, and entrapped air in lines.

Peristaltic Pumps


Rotor with equally space cams (3 to 8 in number) squeezes flexibletubing, forcing liquid to move through it.


Motor speed controller to regulate flow rate; pulse dampener; supplyof spare tubing or tubing cartridges.


Excellent with virtually any type of liquid; liquid only contacts tubing;for continuous flow only; multiple lines can be run from a single rotor;tubing has limited life; flow rate may vary as tubing distorts throughusage; requires pulse dampener.

The choice of which option to choose from those listed above depends onseveral factors, some of which will be apparent from the descriptions thathave been given (e.g. single-shot versus continuous flow.) However,there are additional factors that play a role in the selection process. Theseinclude:

CostRuggedness in the operating environmentPrecision requiredFlow rates or shot sizes requiredMaintenance


SONO TEK

Within each category of liquid delivery system options, there arenumerous variations available that allow a system to be tailored to aspecific application, and that take into account the factors listed above.The choice of a configuration best-suited to a specific application shouldbe made with the assistance of our trained staff. For further information,contact Sono-Tek.

4.2 NOZZLE /LIQUID DELIVERY SEQUENCING

In general, an ultrasonic nozzle should be energized only when there isliquid flowing through it. Keeping a nozzle energized without liquid flowintroduces the risk of overheating the nozzle and the liquid containedwithin it. In addition, because leaving a nozzle ON without liquid flowresults in an internal temperature rise, thermal instabilities will occur whenflow is resumed, which may have a destabilizing effect on the entire sprayprocess.

Although there are no hard-and-fast rules, we recommend that a nozzle beturned OFF no more than 5 - 10 seconds after liquid delivery has ceased.Although leaving the nozzle ON for a few minutes without liquid flow willnormally not damage the nozzle, there is a good possibility that the liquidcontained within the nozzle, depending on its thermal characteristics, willbe adversely affected.

Under certain conditions, such as rapid on/off cycling of spray ( e.g. aprocess in which the duty cycle of the spray is one (1) second on and one(1) second off), it may be desirable to leave the nozzle ON constantly andonly interrupt the flow. This type of cycling will not significantly affectthe thermal equilibrium of the process. However, it is important to pointout a potentially detrimental side-effect of operating the system in thismode.

Since ultrasonic nozzles are vibrating devices and the direction of vibrationis along the central axis, there is a tendency for the liquid to be “pumped”out of the exit orifice of a nozzle, even though the liquid delivery is OFF.This produces a very small, but discernible “wisp” of spray that may beobjectionable, depending on circumstances. It is particularly important toavoid this when precise shot sizes are required.


SONO TEK

In all cases, the nozzle MUST be activated before starting theflow of liquid. If liquid is flowing through the nozzle prior toenergizing it, the possibility exists that the atomizing surfacewill become overloaded with the liquid causing the nozzle tostall, as evidenced by an inability to sustain atomization.

Power to the nozzle MUST be left on until liquid flow stops;otherwise, liquid will accumulate on the atomizing surfaceand could possibly cause the nozzle to stall on the next start-up.

The time duration between nozzle ON and liquid delivery system ON should,at a minimum, be at least 250 milliseconds. The minimum time durationbetween the complete cessation of liquid flow and turning the nozzle OFFshould be similar.

4.3 PLUMBING

Incorrect liquid line plumbing is a common problem source. Air or liquidleaks generally lead to one or more of the following: inconsistent flow,unstable spray patterns and dripping from the nozzle after the system hasbeen turned off. Any air in the liquid lines, whether arising from leaks orgas entrapped in the liquid source itself can degrade performance.

It is particularly important to check fittings on the inlet side of the deliverysystem, where air is most likely to be drawn in through a leak. However, aircan also be drawn in on the outlet side under certain conditions so that allfittings should be carefully inspected. Try to keep the number of fittingson both the inlet and outlet sides to an absolute minimum. The fewer thenumber of connections, the less is the likelihood of leaks.


SONO TEK

In systems designed for very low flow rates (in the microliter/sec range),attention to the integrity of the plumbing is even more critical becauseeven small defects can lead to poor spray consistency. Sometimes inthese low flow rate systems, air can become trapped in pockets at transitionpoints such as fittings, flow meters or even in the nozzle itself. It is oftenpossible to free these air pockets by lightly tapping on the suspectedoffending part.

Avoid using very flexible tubing for low flow applications, particularlywhere precise metering is required. Elastic types of tubing can expand andcontract with pressure and flow variations, resulting in inconsistent liquiddelivery.

It is also important in critical applications to pay attention to the size of thelines. The lines on the inlet side of a pump or other delivery device shouldbe larger than those on the outlet side in order to avoid pump starvation orcavitation. Further, on the outlet side, if more than one size line is used(that is, if different lines are spliced together through fittings, etc.) makecertain that the tubing interior diameters progressively decrease or remainthe same in the direction of flow. The smallest diameter tubing should beconnected to the nozzle fitting. This practice will reduce the possibility ofcreating air pockets at the transitions.

A final comment regarding plumbing concerns the relationship of line sizeto flow rate requirements. Try to keep tubing diameters consistent withthe delivery rate. You certainly would not use a fire hose to water yourgarden. The conduit size is inappropriate for the flow rate required. Thesame holds true in plumbing your Sono-Tek system.

4.4 NOZZLE POWER SETTINGS

The ultrasonic atomization process is highly dependent on the powerdelivered to the nozzle. Best results are achieved within a relatively narrowinput power range. Below a critical power level, referred to as the “stallpoint”, there is insufficient energy to produce atomization. The powerrange in which atomization proceeds normally is generally confined to anarrow region, approximately 0.5 - 1.5 watts above the stall point. Atpower levels above this range, the liquid is literally “ripped apart” by theexcess energy provided, causing large chunks of material to be expelled,


SONO TEK

rather than the characteristic soft spray of fine drops. This condition isknown as cavitation. The actual power at which the stall point occurs isdependent on several factors. These are:

Nozzle type (mechanical and electrical characteristics, size)Liquid characteristics (e.g. viscosity, solids content)Flow rateSize of the atomizing surface

Each nozzle type, because of its specific geometry and other factors, willgenerally have a different stall point for the same liquid. For example, thestall point of a 48 kHz nozzle, designed with a conical atomizing surface todeliver a wide spray pattern at substantial flow rates, may be in theneighborhood of 3.5 - 4 watts of input power when atomizing water.Another nozzle, operating at the same frequency, but designed for microflowoperation (a very small atomizing surface), may have a stall point at only1 - 1.5 watts when atomizing water.

The type of liquid being atomized strongly influences the minimum powerlevel. More viscous liquids or liquids with high-solids content generallyincrease the minimum power requirement. For example, the nozzle mentionedabove might require at least 8 watts of input power if the liquid beingatomized were a 20% solids-content, solvent-based material, or a pureliquid with a viscosity of 30 cps.

The flow rate also plays a role in determining minimum power level. For agiven nozzle, the higher the flow rate, the higher will be the power required,since the nozzle works harder as the flow rate increases.

The power setting (watts), controlled by the POWER ADJUSTpotentiometer on the front panel, has a profound influence onthe quality of the spray that is produced.

It is important to understand the relationship between powersetting and spray characteristics before attempting to useyour Sono-Tek Ultrasonic Atomizing Nozzle System.


SONO TEK

Orifice Dia. (in.)Atomizing Surface

Dia. (in.)Maximum Flow

Rate (gph)

0.020 - 0.040

0.052 - 0.067

0.086 - 0.100

0.141

0.250

0.09 - 0.25

0.24 - 0.35

0.30 - 0.45

0.46 - 0.50

0.65

0.07 - 0.3

0.5 - 0.8

0.9 - 1.7

2.4 - 3.3

6.0

In order to determine the stall point for your configuration, and to setyour system to the optimum power level, perform the followingprocedure:

1. Set the nozzle power level to its maximum power setting (15 watts for25, 48,and 60 kHz nozzles; 5.5 watts for 120 kHz nozzles; and 20 wattsfor 35 kHz nozzles).

2. Deliver liquid (the material you intend to work with) to the nozzle atthe maximum flow rate you anticipate will be used.

3. Reduce the power level slowly, observing the reading on the powermeter, until atomization ceases. Note the value at which this occurs.It is the stall point. Turn off the liquid flow.

4. If the stall point is less than 1.5 watts, increase the power level to 0.5watts above the stall point value. If the stall point is greater than 1.5watts, increase the power level to 1 watt above the stall point value.Resume the flow of liquid. The spray should now be optimized.

4.5 MAXIMUM FLOW RATE VS. NOZZLE ORIFICESIZE AND ATOMIZING SURFACE AREA

Every Sono-Tek ultrasonic atomizing nozzle has a well-defined upper flowrate limit, determined both by its exit orifice diameter and the area of theatomizing surface. The chart below displays the maximum flow rate rangefor various combinations of orifice and atomizing surface diameters formost of our standard nozzle designs.

The data presented is based on the atomization of water at ambienttemperature and pressure, and is intended to serve as a guide only. Factorsrelating to the nature of the liquid to be atomized, such as viscosity, vaporpressure, solids-content, density, and polymer chain length, or ambient


SONO TEK

pressure/vacuum conditions, can have a significant effect on themaximum flow rate achievable. Maximum flow rates can varysignificantly from those listed. If you have questions about a specificliquid, please contact Sono-Tek. Our sales and engineering staffs willbe able to assist you.

4.6 FLOW RATE RANGE

The flow rate range, that is, the ratio between maximum and minimum flowrate for a given nozzle (turn-down ratio) , is generally in the range of 5:1.

Since ultrasonic nozzles do not rely on pressure for atomization, theytheoretically have an infinite turn-down ratio. However, in practical terms,lower limits do exist. As the flow is reduced, a point is reached where thevelocity becomes so low that the liquid emerges onto the atomizing surfacein a non-uniform circumferential manner, causing the atomization patternto become distorted.

In some applications, where stable spray patterns are unimportant (e.g.some chemical reaction chambers), this distortion may be tolerable. Inother applications, where the integrity of the pattern is vital (e.g. surfacecoatings), the low-velocity stream distortions are unacceptable. Thejudgment as to whether or not the turn-down ratio can be extended beyond5:1 is highly dependent on the specifics of the application. Please contactSono-Tek for additional information.

4.7 DROP SIZE DISTRIBUTIONS

Drop size in an ultrasonically produced spray is governed by the frequencyat which the nozzle vibrates, and by the surface tension and density of theliquid being atomized. However, frequency is the predominant factor.Median drop size is inversely proportional to frequency to the 2/3 power.Thus, the higher the frequency the smaller the median drop size.

Typically, the drop size distribution from ultrasonic nozzles follows a log-normal distribution curve. In simple terms, this distribution has the familiarbell-shape but on a logarithmic scale. The chart below shows thisdistribution on a cumulative basis for several nozzle frequencies for water.


SONO TEK

Various parameters can be used to characterize the mean and mediandrop size of a particular drop distribution. The number median diameterdefines the 50% point in drop size - that is, one-half of the number ofdrops in the spray have diameters larger than this value while the otherhalf have diameters smaller than this value. The number mean and weightmean diameters are average diameters. The number mean diameter isobtained by adding together the diameter of each drop in a spray sampleand dividing that sum by the number of drops in the sample. The weightmean diameter is obtained by adding together the volume of each drop in

a spray sample (volume is proportional to diameter cubed), taking thecube root of this sum, and finally dividing by the number of drops. TheSauter mean diameter is a specialized parameter used primarily incombustion applications. It measures the effective ratio of drop volumeto surface area.

2 4 6 8 10 20 40 60 80 100 2000.01

0.1

0.512

5

10

20

30

40

50

60

70

80

90

95

98

9999.5

99.9

99.99

Drop Diameter (microns)

Perc

en

to

fd

rop

sb

elo

wg

iven

dia

mete

r[F

(d)]

1

120

4835

25

60

Number median diameterNumber mean diameterSurface mean diameterWeight mean diameterSauter mean diameter

Oper

atin

g

freq

uen

cy(k

Hz)

Data compiled for water.Other materials may givedifferent results.


SONO TEK

5.0 OPERATING INSTRUCTIONS

Before attempting to operate your Sono-Tek UltrasonicAtomizing Nozzle System, read Section 4 of this documentin its entirety. Failure to comply with the recommendationsand procedures contained in Section 4 may result inunsatisfactory system performance.

5.1 INITIAL START-UP

1. Assure that the nozzle system has been installed in accordance withthe instructions regarding setup (Section 3).

2. Make certain that the liquid delivery tubing and the electrical cableconnecting the nozzle and the Broadband Ultrasonic Generator are inplace.

3. Turn the system ON and turn the POWER ADJUST knob counter-clockwise until the reading on the watt display is 0.0 watts. The knobdoes not have a mechanical stop on either end of its range. The actualrange, from 0 to maximum power, is internally controlled.

Note: If using the external trigger input option to energize thenozzle, refer to Section 5.2 for specific instructions about using thisfeature before proceeding.

If using the external power control option to control input power tothe nozzle, refer to Section 5.3 for specific instructions about usingthis feature before proceeding.

4. Turn the POWER ADJUST knob (or the external power control) upgradually and confirm that the power observed on the generator’swatt display increases in a smooth manner.


SONO TEK

5. Set the power level to approximately 10 watts, except for nozzlesoperating at 120 kHz. Carefully note the caution below for 120 kHznozzles (designated as models 8700-120).

For nozzles operating at 120 kHz (models designated as 8700-120), NEVER OPERATE AT POWER LEVELS ABOVE 5 WATTS.Operating in excess of 5 watts will result in rapid failure dueto the likelihood of excessive heating, even with full liquidflow!

6. Turn on the liquid flow at a rate consistent with the anticipated flowrate for the application.

7. Observe that the nozzle is atomizing.

8. Turn the power level down gradually until you observe that the nozzlehas stalled (atomization ceases). Note the setting where this occurs.

9. Turn the the liquid delivery OFF. Increase the power setting until theatomizing surface has cleared itself of liquid. Turn the liquid flow ONagain. Set the power to exactly one (1) watt above the power level atwhich the nozzle stalled. (See Section 4.4.)

10. The power setting arrived at above should be optimum for yourprocess. If it is not, raise the power slightly, but no more than two (2)watts above the stall point.

Note: Power settings are also related to flow rate. If you intend touse flow rates higher than chosen in step 6, it may require that thepower be increased beyond the level determined in steps 8 - 9above.

11. Turn the flow of liquid OFF before turning power to the nozzle OFF.This will prevent unatomized liquid entering the process stream. (SeeSection 4.2 for complete details on nozzle/liquid delivery sequencing.)


SONO TEK

5.2 External Trigger Input

The external trigger input function enables the system to remotely energizeand de-energize the power to a nozzle, bypassing the internal circuitry ofthe Broadband Ultrasonic Generator. In order to activate this function, anoptional cable is required (p/n 06-01078) that plugs into the rear of thegenerator and connects, on the other end, to the trigger input signal.

The cable can be configured by the user to accommodate one of thefollowing inputs from an externally supplied control signal :

A N/O (normally open) switch or relay contactB N/C (normally closed) switch or relay contactC 3 - 11 volts (AC or DC)D 12 - 48 volts (AC or DC)E 70 - 240 volts (AC or DC)

In order to install and operate this feature, execute the following steps:

1. Select the type of trigger input signal you will be providing from thelist above.

2. Prepare the free end of the cable for the selected input mode, asdirected below. In every case cut off unused wires so as avoid thepossibility of shorting or otherwise interfering with the properoperation of the cable.

A N/O (normally open) switch or relay contact

Connect and solder the black wire to the white wire. Connectthe red wire to the positive (+) side of the switch/relayterminals (if +/- polarity is required) and the blue wire to thenegative (-) side of the switch/relay terminals.

B N/C (normally closed) switch or relay contact

Connect and solder the black wire to the white wire. Thiscombination forms the positive (+) side of the connection (if+/- polarity is required) to the switch/relay. Connect andsolder the blue wire to the red wire. This combination formsthe negative (-) side of the connection to the switch/relay.


SONO TEK

C 3 - 11 volts (AC or DC, polarity insensitive)

Connect the green and red wires to the voltage source.

D 12- 48 volts (AC or DC, polarity insensitive)

Connect the black and red wires to the voltage source.

E 70 - 240 volts (AC or DC, polarity insensitive)

Connect the brown and red wires to the voltage source.

3. In order to activate the external trigger input, it is necessary to removejumper J2, located on the horizontal printed circuit board inside theBroadband Ultrasonic Generator, in the position shown below.

Dangerous voltages are present in Broadband UltrasonicGenerators supplied with AC voltage (p/n 06-05108).

Before attempting to remove or replace jumper J2 in eithermodel Broadband Ultrasonic Generator, make sure that it isturned OFF and disconnected from its power source.Removing or replacing jumpers while power is applied maynot only provide a risk for electric shock, but also will causedamage to the generator.


SONO TEK

3. Turn OFF power to the Broadband Ultrasonic Generator and plugthe connector end into the jack labelled EXTERNAL POWERADJUST located on the rear panel of the generator.

4. Turn power ON to the generator and then apply a control voltage.Verify on the WATTS panel meter that the power to the nozzle can bevaried up and down by adjusting the control voltage. The generatoris configured such that a 1 VDC increment is equivalent to a 2 Wpower increment.

5. Return to the set-up procedures in Section 5.1.

5.4 ALARM OUTPUT

The alarm output function enables the user to receive a separate nozzleerror status indication, via normally open or normally closed contactsfrom a relay built into the Broadband Ultrasonic Generator, for use with analarm, in addition to maintaining the normal error functions built into thegenerator. (Error light for both models 06-05108 and 06-05112; audiblealarm for model 06-05108 only). In order to activate this function, anoptional cable is required (p/n 06-01084) that plugs into the rear of thegenerator and connects, on the other end, to the user’s alarm device.

When using external power control, the system will displayan error if the external control voltage is 0 VDC. To avoid this,always shut OFF the main input power to the generator whennot atomizing, or provide a small control voltage signal (lessthan 0.5 VDC) when the system is “idling”.

When using the external trigger function in conjunction withthe external power control function, the above proceduresare not required.


SONO TEK

In order to install and operate this feature, execute the following steps:

1. Select normally open (N/O) or normally closed (N/C) operation.In the event of an error condition, the contacts will close for the N/O configuration and open for the N/C configuration.

N/O Connect the green wire to one relay contact and the blackwire to the other. Clip off the red wire. It is not used.

N/C Connect the red wire to one relay contact and the blackwire to the other. Clip off the green wire. It is not used.

2. Turn OFF power to the Broadband Ultrasonic Generator and plugthe connector end into the jack labelled ALARM OUTPUT locatedon the rear panel of the generator.

3. Remove one end of the cable that connects the nozzle to thegenerator. This will cause an error signal to be transmitted.. Turnpower ON to the generator. Verify that the relay is respondingproperly. Turn the generator OFF immediately.

The contacts of the relay contained in the BroadbandUltrasonic Generator are rated for 24 VDC or 120 VAC,maximum. Make certain that the alarm device connectedto this output does not exceed these ratings. Voltages inexcess of the rated values will quickly damage the relay.


SONO TEK

Nozzle will not atomize

Check to see that all interconnecting cables are securely fastened.

Be certain that the nozzle is mounted according to the instructions containedin Section 3.2.

Verify that the active parts of the nozzle are not in contact with orconstrained by some other structure.

Verify that the Broadband Ultrasonic Generator is powered up.

For the external trigger option only -- establish that the proper triggersignal is present. (Section 5.2.)

Check to see that nozzle power adjust knob (or external power control, ifused) is at a setting sufficient to atomize the liquid. (Section 4.4)

Make sure the liquid delivery system is on and liquid is flowing throughthe nozzle.

Check to confirm the Swagelok R fitting is securely tightened on the liquidfeed tube. A loose fitting can absorb power from the nozzle and becomequite hot.

Check for a short circuit condition in the cable and nozzle.

No liquid delivery

Check for a clogged nozzle or feed lines.

Verify that the delivery system is installed and operating properly.

Nozzle produces irregularly large drops

Check to see if the power setting is too high.

6.0 TROUBLE-SHOOTING CHECKLIST


SONO TEK

Some liquid emerges unatomized or maximum flow is lower thanexpected

Confirm that the flow rate does not exceed the nozzle’s rated capacity.

If the nozzle cannot sustain the rated flow rate for the liquid being atomizedit may be because of surface tension, viscosity or other propertiesassociated with the liquid under test. Contact Sono-Tek for suggestions.

Check to confirm that the Swagelok® fitting is securely tightened.

Liquid continues to exit the nozzle orifice after the liquid delivery hasbeen turned off

Check for leaks at all fittings and the pump.

If using a solenoid shut-off valve or equivalent, verify that it is operating properly.

Make sure that there are no constrictions in the lines leading to the nozzle,and that the tubing being used does not present an undo restriction to flow.After the liquid is turned off, the pressures resulting from restricted flow mustbe relieved, sometimes causing an “after-drip” from the nozzle orifice.

Broadband Ultrasonic Generator becomes unusually hot

If you are using the external power control feature, check that the internalpower setting on the generator is 0.0 watts.

Nozzle System continues to fail to atomize

Contact Sono-Tek for authorization to return the system.

Do not attempt to make repairs unless directed to do so byus. There are no user serviceable parts within theBroadband Ultrasonic Generator or nozzle.


SONO TEK

7.0 MAINTENANCE

Caution: Cleaning should be done carefully to avoid marring the nozzlesurfaces. Care should be taken to avoid material build up on any nozzlesurface and particularly on the atomizing surface. Significant build upmay result in nozzle malfunction.

Prior to cleaning, turn the system OFF and disconnect the interconnectingcable and liquid delivery tubing from nozzle.

If possible, flush the nozzle with an appropriate solvent after each use (forexample water or isopropyl alcohol).

If significant build up of material occurs, use the following methods toclean the nozzle atomizing surface and or the liquid feed passage:

For nozzles with relatively large orifices, the liquid feed passage may becleaned by inserting a pipe cleaner or small round brush into the nozzleorifice or liquid feed tube end of the nozzle. For best results, make severalpasses through the nozzle. Never attempt to drill out material hardened inthe liquid feed passage.

The nozzle tip (atomizing surface), may be cleaned using a mild scouringabrasive (such as steel wool or “Softscrub” tub and tile cleaner).

Do not immerse the nozzle in an ultrasonic cleaning tank or any othercleaning bath.

Immersing the nozzle in a bath may allow liquid to penetratethe housing and short out the piezoelectric transducers,thereby rendering the nozzle inoperative.


SONO TEK

Special Procedure for Nozzles with a Microbore Tubing Assembly

Sono-Tek strongly recommends that our customers use one or both of thefollowing methods to clean microbore assemblies and prevent them fromclogging:

Atomizing with a cleaning solvent:

a. With the unit fully assembled, plumb a source of a cleaning solventto the nozzle.

b. Collect the waste in an approved fashion from the nozzle tip.c. Energize the nozzle at an appropriate power level for the solvent

(typically, about 2 - 3 watts) and run solvent through the nozzle for afew minutes.

Energize the nozzle tip in a solvent bath:

a. With the unit fully assembled, prepare a bath of cleaning solvent intowhich the atomizing stem of the nozzle (the slender portion of thefront horn) can be submerged.

b. Energize the nozzle. The power setting will vary and you can expectthe nozzle to stall when it is submerged. We suggest that the powerlevel be increased for this procedure to 80% of the nozzle’s maximumallowable power. (See Section 4.5.)

c. Dip the nozzle stem repeatedly into the solvent bath; do not allowmore than 75% of the atomizing stem to be submerged. After eachcycle of submerging the nozzle, with the nozzle still energized, wipethe tip with a soft towel.

d. Repeat 5 times. This process should not take more than 2 minutes tocomplete.

We painstakingly assemble each microbore assemblyinto a nozzle. We have found that customer attempts toremove the microbore assembly usually results inassembly failure. We strongly urge that if the assemblymust be cleaned, you follow the procedure describedbelow.


SONO TEK

8.0 LIMITED WARRANTY

Sono-Tek warranties ultrasonic nozzle products and accessories (“Product”)against defects in materials and workmanship for a period of 12 monthsfrom the date of shipment. Because of the chemically aggressive nature ofmany liquids, this warranty does not extend to damage caused by usingthe Product with liquids that are chemically incompatible with materials ofconstruction of the Product intended to come into contact with liquidduring normal operation.

This 12 month warranty is subject to the following conditions:

• In the event of a Product, or part of a Product, proving to be defective,the obligation of Sono-Tek shall be limited to the supply of a repairedor replacement Product, or part of a Product, at its sole discretion. Ifa Product appears to be defective, purchaser must notify Sono-Tekimmediately to obtain instructions to rectify the problem. Parts orProducts must only be returned to Sono-Tek after a ReturnAuthorization number has been issued, and must be shipped freightprepaid.

• Repairs or replacements necessitated by misuse, abuse or improperoperation or application of a Product are not covered by this warranty.

• Damage caused by unauthorized repair to, or alteration of a Product isnot covered by this warranty.

• Items of an expendable nature including, but not limited to, plastictubing, fittings, fitting ferrules, filters, and cables are not covered bythis warranty.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES,EXPRESSED OR IMPLIED, AND WARRANTIES OFMERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSEARE EXPRESSLY EXCLUDED. SONO-TEK CORPORATION ACCEPTSNO LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES,HOWSOEVER CAUSED.

2012 Route 9W, Bldg. 3

Milton, NY 12547

Phone: (845) 795-2020

Fax: (845) 795-2720

E-mail: [email protected]

Web Site:www.sono-tek.com

Sono-Tek reserves the right to make changes to theproduct(s) described herein without notice. No liabilityis assumed as a result of their use or application. Norights under any patent accompany the sale of anypatented product. Copyright © 2007 Sono-TekCorp. All rights reserved.Printed in the USA P/N: 11-01049

Documents

Ultrasonic Atomizing Nozzle Systems