How Do You Make Liquid Drops in Quantity?

Methods to make liquid droplets of uniform size in large quantities?

Adjust the spray pattern to give desired droplet size.

Spray the drops into a freezer chamber, let them fall into a container, keep them frozen.

Dip n Dots?

Your gave absolutely no info.

did you see how they make dots

You really need to supply more information for us to attempt to supply a meaning full answer, there just isn't enough to go on. Uniform drop size is one thing but uniform freezing adds to the complexity.

Drop size, degree of uniformity/repeatability, liquid type, quantity, purpose/application, etc, etc.

Start by giving us an idea of the size and nature of the droplets and whats the intended use.

A bunch of these hollow needles in a tube, feed liquid in 0 pressure....size needle hole to viscosity of liquid....

Chester shot tower

What's wrong with a bucket with holes in the bottom?

Make sure that the holes are far enough apart that the drips do not interfere with each other.

Make sure that the level of liquid in the bucket remains constant.

As others have said study shot towers.

What is the liquid? What temperature does it melt/solidify?

Desired size is 3mm/.125".

The liquid is sulfur, which melts at 240 deg. F.

Sulfur, may be too volatile for a shot tower. There has to be tests done on a small scale.... very small scale. In a oxygen controlled environment.

Do you have a tolerance like 2-4mm~5/64"-5/32"

Yes, there is some tolerance from 3mm.

Why not keep that to yourself?

You might have said that earlier.

The simple way is to maintain density, viscosity and flow rate. In the case of molten sulphur, the first two are a function of temperature.

Or forget about the holes and leave all the drops in the bucket and tell your boss they are equally sized and transportable.

That last comment was just a drop in the old bucket.

I believe what you need is a prilling process. From Wiki:

Prill

From Wikipedia, the free encyclopedia

A prill is a small aggregate or globule of a material, most often a dry sphere, formed from a melted liquid. Prilled is a term used in mining and manufacturing to refer to a product that has been pelletized. The pellets are a neater, simpler form for handling, with reduced dust.

The material to be prilled must be in a solid state at room temperature and a low-viscosity liquid when melted. Prills are formed by allowing drops of the melted prill substance to congeal or freeze in mid-air after being dripped from the top of a tall prilling tower. Certain agrochemicals such as urea are often supplied in prilled form. Fertilizers (ammonium nitrate, urea, NPK fertilizer) and some detergent powders are commonly manufactured as prills.^[1]

Melted material may also be atomized and then allowed to form smaller prills that are useful in cosmetics, food, and animal feed. Prills have also been used to protect active ingredients from exposure to environmental factors and to cover up the flavor of bitter nutraceuticals.

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Some more ideas here:

http://niik.ru/en/technology/technology-granulation-prilling/

http://www.slideshare.net/khalidnawaz754/prilling-tower-and-granulation

https://www.google.com/search?q=prilling+tower+process&sa=X&biw=1832&bih=990&tbm=isch&tbo=u&source=univ&ved=0ahUKEwjcy5XV4JvPAhUBbiYKHUMzCmMQsAQIQg&dpr=1

Yes, that is actually what we are trying to make but looking for alternatives to current methods. Step 1 is making the small drops of approx. 3mm size.

Have you done any initial trials? If so, what size beads were you able to get?

Yes, we have made them with the use of a pan with small holes drilled in the bottom (same as the bucket method I suppose) but was looking for something that might be more scaled up more easily to get more drops without increasing the area of the drop tower.

To get more product, you need vastly more heat exchange, you need more head pressure (could be dangerous?), and then you will have to turn up the frequency to match with the flow rate, but I would stay away from placing too many nozzles close together, or you may get problems with semi-liquid droplets sticking together.

You may be forced to increase the drop height to ensure that with higher production, you have solid beads at the bottom.

One place I worked at used an interesting technique of feeding the melt liquid through a capillary tube to which a glass rod was in contact and this was glued to a speaker cone, and they adjusted frequency according to the capillary size, density, and surface tension of the liquid melt. The droplets were in a statistical class where the standard deviation was about 0.5% of the mass of the droplets.

Solidification of the droplets took place during the fall time (not even one second for a fall of about 4 feet), since these were high melting inorganic salts, or mercury amalgams of sodium, and some added rare earth elements. It was for lighting production.

Liquid nitrogen or other cryogenic liquid could be utilized to effect the cooling. The droplets had to fall through an inert gas at low pressure, helium would transfer heat the best I suppose. When things were set up right (liquid column pressure above the capillary, etc.), the droplets would be round beads by the time they reached the collection vial, which was spun off with a glass melting torch at the end of the cycle.

When things did not go right, one could have a partially congealed mess at the bottom, even beads that did not fall "straight", and these could stick to the neck of the vial.

Very interesting. May try something like that.

Aren't there small candies that are generally spherical in shape? Anyone know how those are made?

Those spherical candies may be molded, en masse.

For 3 mm beads of sulfur, your frequency might be pretty low, the capillary more of a narrow gauge tube, but there is no reason why the entire thing could not be scaled up larger, if OK for the sulfur to fall through an inert gas like helium that was being circulated over a heat exchanger. The audio might even be applied directly to the sulfur container with a plate in the bottom with numerous tubes extending. The liquid has to (obviously) be very clean or the nozzles will stop up.

Quite some time ago I saw some of this on a 'How It's Made' type of show. Chocolate has a bit of wax added to it and then "tumbled" in a machine similar to a dryer. I believe chocolate was added a bit at a time to make balls. I think malted milk balls?

The memory is vague, and anyway, this probably doesn't help your situation.

How fussy are you?

More that this. See how they have a flat side and aren't really uniform in size. Hoping to have better product uniformity.

so, is there a clay mixed (Binder) into your batch?

I thought Lyn introduced that into the mix. I don't think the acoustic induced droplet separation would work very well at all with the rheological properties of sulfur liquid and bentonite suspension.

Speaking of rheology, I meander to theology when God rained down fire and brimstone on Sodom and Gomorrah. Kinda reminds one of such, does it not?

Yes, sure does!

The melt/form/freeze method leads me to think that we don't know what Flyboy really wants to accomplish. That sounds like a complicated process if he just wants to end up with sulfur balls.

So, why not start with sulfur powder and use a pill press?

Pill Press Machine: Business & Industrial | eBay

No reason why not, especially if the profile is round (two hemispheres make on sphere, correct?)

a press to press sulfur into pills... advance with caution.

Keep in mind, that sulphur ill need some type of binder, such as Lignin or corn starch..

Yes, there could be up to around 10%.

What exactly is the application or need for such accurate and spherical sulphur balls?

OK here's a crazy idea.

Increase the pressure in the whole room to 2 bar.

Make a large conical tank with a heating element around the top, and a bucket with holes in the bottom fixed in the top.

Fill the tank with cold water; heat the top to 245°F (water boils at 250°F at 2 bar); pour the molten sulphur into the bucket.

Sulphur is insoluble in water, and, slightly denser than water. It will remain molten for the first part of the fall but solidify quickly when it gets into the cooler water.

Once the tank is about 1/10 full stop the process, and empty the tank from a large sealable door at the bottom.

When they manufacture plastic pellets/beads for later use in injection moulding, the "compounder" extrudes the essentially melted product into a water vat with a rotating shear cutting the exruded material off, determining pellet size.

The water flow rate past the extruder removes the pellets from the cutting zone and they are screened from the flow. The water just recirculates. Pump speed determined "cooling" time for the pellets.

The beads removed from the hot water cary enough residual heat to dry effectively.

Water behaved OK for plastics with Heat Deflection Temperatures (HDT) up to 200 Deg C.

Industrial printers make tens of thousands droplets per second.

Pus a continuous liquid jet, excite at the right frequency (depends on superficial energy, size of droplets, and density) and you will get thousands of droplets of uniform size.

Not a bad concept. 3D printing of Sulphur spheres.

Just some arrangements for the fine details and its a go!

How about feeding the solution/material through a downward facing "mincer" style machine?

The speed of the rotating "cut off" blade will determine the size of the droplets/pieces.

Then maybe rolling these mouldable cut-off pieces down a vibrating incline to "form" the spheres?.

(then roll into a bag? for jam on it? ) This could make a very fast continuous operation?

Hope this helps. jt.

A farmer bought a hen in the market and before going home decided to go to the Cinema.
The ticket seller refuse to let him in saying "you cannot bring that hen in here, sorry."

Not to miss the film, he put the hen down his trousers, went back in, bought his ticket,
and sat in his seat. Two ladies came and sat by him.

After the film started he opened his trousers and let the hen poke it's head out to get some air.
The one lady whispered to the other " he's opened his trousers next to me.. and it's popping out!"

"Take no notice" said her friend, "at our age we have seen it all before."

"Never like this" she said, "it's eating my popcorn!"