Where do I Find Paddle Designs for Pin Homogenizers?

I should add that the metal pins to be homogenized will be about 24Kg, with a volume of around 753 cubic inches in the homogenizing chamber.

I cannot use any exixting homogenizers, as my chamber must be installed in a custom process control chamber, and the pins need only to be constantly homogenizing during the process for uniform treatment.

Thanks!

Do you , or have you worked with CAD...

No, don't and I haven't worked with CAD. I will be employing an engineer who does. For now, I want to get a start on the design with resources to aid in the design. I assume this design consideration is a specialty that almost any engineer will need to research, and the engineer I want to employ is already working 70 hours a week...

How does one homogenize a pin? Or even a gaggle of pins?

O.K. specificity is a bit lacking... There are a LOT of small pins in the process lot.

A pin is a pin, is a pin, is a pin. How do you homogenize a single item?

Or, even a group of single identical items.

Are we plating these pins?

Is it my literal brain that isn't capable of understanding this term?

The lot of pins will be exposed to a chemical process that takes significant time to react. Since I want each pin to receive the same treatment in the batch process, I want them continually mixing by rotating the cylnder. Imagine, if you will, something spraying on one part of the surface of the batch, and it is contiually mixing so each pin eventually gets the same treatment. It will take maybe 8 hours for the batch to receive this treatment, and I want the pins to mix during this time for even treatment.

This mixing action...

Do you foresee gentle (rocking a baby), aggressive (portable concrete mixer), or very aggressive (paint shaker) action?

Or is that definition part of your investigation?

I would like the pins to be gently brought from the bottom edge, and carried by the paddles through rotation to be spilled onto the top center of the lot mass. I am anticipating about 3-4rpm, with perhaps three paddles penetrating 20-25% into the mass along the side in a corkscrew type path with an angle that will be able to carry 4-7% of the mass at each rotation.

How about a clothes dryer tub design?

This clothes dryer design does not, in my estimation, allow me to have the cylinder at 70% full, and mix the pins both horizontally and vertically. The pins will be exposed to the chemical treatment, which will penetrate approximately 5% into the mass, from one end of the mesh-covered cylinder (a requirement). To get the whole lot exposed evenly, the pins need to mix from front to back while the cylinder rotates.

The vanes could be set at angles and the rear of the cylinder could have vanes as well...

The cylinder is 13" long and 5" Daimeter. the paddles need to carry the material up to the top as I have described. I have the basic design described. I am hoping for an example of some proven design that will keep mixing this material throughout the chamber in an evenly mixed way throughout the mass, and process.

GA. Why reinvent the Wheel Barrel?

Show me something that does this, and I will not reinvent it... Show me how to do it, and maybe there is a new invention in the works...

So it looks like you need to adapt a typical plating barrel to a super sized pin homogenizing,2 x paddle, plating barrel? Does this sum it up?

The process will be carried out at a temperature of up to 1000 degrees Centegrade. A metallic design will be necessary. And yes, the mesh sides and ends like the plating bath cylinders will be in order.

1000 deg C would have been worth mentioning much earlier, I find your process as described very hard to fathum...

It's not the process that is important; The mixing mechanics are what I need help with.

Thanks!

You do realize that 1000C means the process is important.

That is above the melting point of Aluminum, Brass, all plastics, and almost ready to melt copper. That temperature greatly reduces your options for materials. Mild steel at that temperature is likely in the Austenite range...

Your process is what determines your mechanics.

It went from simply designing a large steel rotating drum with some fins inside...

To...

designing a large drum, with (I'm guessing) some type of ceramic lining, with nozzles, that must withstand the heat, and some yet to be known chemicals, which material compatibility must be taken into account. Some geometry might be suitable for some materials, while it might never work with other materials, under certain temperatures, etc etc etc.

Basically what I'm saying, is there is a direct correlation between the process, and the mechanics, they are as interlinked as the sun and earth.

You are right. I only wanted to emphasize that adapting a plastic plating drum would not be an option. I checked with my process requirements, and an upper limit of 800C will be sufficient. That's still a very high temperature. I believe I will need to consult with a metallurgist to find a suitable metal for this project that is strong enough to hold 50lbs of product at temperature, while rotating at an angle.

I believe that most metals will be chemically compatible with the gas mixture that my process will be using.

I should have known what it would do to you folks when I threw out a number like 1000C.

Thanks for the heads up, though on the temp. As I have looked at the elevated temperature creep ratings for some different alloys, they ceratinly have dropped a lot from their room temperature values.

Thanks.

You're insane. You can't be serious! Have you taken leave of your senses?

You have lost me. What else don't we know?

Sorry, i'm being a bit vague for proprietary reasons... thus the anonomous posting, as well. It is really the mixing paddle design that I am wanting to cover here.

I would rather not go to the expense of having to experimentally build and test various paddle designs. Re-inventing what I believe many companies have already developed seems such a waste of mankind, and my wife's patience.

Thanks.

You're wifes just going to have to deal with many trial and error issues if you intent to pursue this. I cant (nor can the others it seems), imagine what in the world you are actually trying to do.

If she has a vague understanding of your intent, you may consider asking her to post your intent more clearly. Possibly with some drawings, etc.

Good luck, I hope she is not Latin American, they have a short sense of humor with things like waisting money.

Apparently there is not one of you who has a clue about moving material in a drum in the fasion I need to accomplish.

To make this a personal attack is unprofessional. The material selection is a challenge, but not insurmaountable. I have that on good reference.

If you cannot contribute to my request for blade design/configuration, I would appreciate it if you would go elsewhere to spend your time.

Thanks

OK, nothing personal just poking you a bit. Good luck and please let us know when you find someone who has a clue.

Ahhh Merry Christmas to all by the way

It seems to me you have revealed another reason to post this anonymously...

Since we can't read your mind, I'd say you are wasting your time here.

Yep safe to say the interest and fun's all gone here on this one isn't it?

Ho Hum

Any way, GA on 13....

Knowing what I knew at the time, it seemed like a reasonable way to go.

Thanks and have a Merry Christmas.

A plating barrel provides a chemical exposure to the parts from within a homogenous chemical bath. My process is designed to give a directed and metered exposure over time to just a portion of the batch. The process must give short exposure to each pin, on average, accumulatin its exposure over time, ensuring that no one pin is exposed longer that the other pins. This process could be done one pin at a time, but that would be rediculously costly for 500,00 pins. Since the exposure must inherently enter the cylinder from the bottom (round) end, there must be a full mix over an appropriately small time so eventually all the pins get exposed evenly.

It would be possible to have an inner and outer layer of paddles that would do this sort of mixing as a horizontal cylinder rotates, but the friction at 70% full would be large, and the dual paddle design and fabrication would be much more complex and expensive. So I am still looking for some mathamatical formulation or (preferably) a practical example of how to fashion these paddles.

Thanks.

Why don't you use vibratory tumbling, as a method of moving your pins. It keeps the mechanical moving parts away from the high heat and product. Sweco is one manufacturer of these type of machines, I'm sure there are others. Perhaps you could modify one of their machines to suit your needs.