Difference between revisions of "Batch Agglomerators"

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[[File:Continuous Agglomerator.jpg|thumb|right|Batch Agglomerator]]
'''Agglomerators''' are used to increase the particle size of powders. They are very useful for powders of different particle sizes and/or densities that would otherwise seperate when handled. They are used when minor ingredients, often expensive ingredients, must be uniform throughtout a powder.


[[File:Bead_press.jpg|thumb|right|Bead press]]
There are two basic types of agglomerators; compaction and noncompaction. The compaction type uses mechanical pressure (and often very high pressures) to "press" the powders together. For these, binders are sometimes not needed to make the particle. Compaction agglomerators are highly specialized, and not addressed here.
 
[[File:Bead_press_roller.jpg|thumb|right|Bead press roller]]


[[File:Bead_presses.jpg|thumb|right|Bead press]]
Any system that consists of at least one powder of any size, or mixture of sizes, and a liquid binder are agglomeration candidates.


Capping beads is a simpler process because the shape of the hole is not as critical. The hole in the cap is critical and should not be too large. The tricky part about capping and riveting beads is how much tubing to use. Too little and you will not be able to set the rivet. If you use too much there will be excess silver that you will not be able to get the silver rivet to lay flat on the cap. Determining the proper length is a trial and error process but it did not take me long to figure it out.
Agglomerators keep the powders mixing while spraying a binding liquid. The binder is sprayed and then dries or sets or cures or otherwise hardens sealing the powders into a single bead. The need to keep the powders well mixed usually works against the idea of agglomeration. [[Mixers]] use high shear for mixing. This high shear also breaks particles down rather then agglomerates them. Ed O'Brien came up with the idea of a gentle mixing within his agglomerator in the 1960s.


Capping and riveting beads is a two step process, flaring the tubing and then setting the rivet. The press is very good for flaring tubing and I have used up to 1/2" inch tubing with no problems. The press has an anvil, the bottom piece with the low angle cone (Fig. #2) This cone makes sure that the tubing is aligned with the die. The die is the top piece and does all of the work and can flare tubing up to 3/16 outside diameter. Watch the top piece when flaring the tubing and making sure that the ends of the flared tubing are symmetrical.


==Process==
==Process==
# The requested production capacities are normally in the range between 1000 and 4000 kg/hr.
# Process is always batch, with significant variations in recipes. This automatically results in easy and fast cleaning intervals geared to preventing taste and smell contaminations.
# The mixing process has to guarantee a low energy input per kg produced product, resulting in visually acceptable quality, without damaging components in the mixture.
# The complete process normally consists of two separate mixing processes. One is the intensive bulk mixing process (starch, salt, fat), the other is the gentle post mixing process of this bulk with the dedicated fragile specific soup components (vegetables, mushrooms, vermicelli, etc). The first intensive mixing process is executed in paddle or plough shear mixers, the second gentle mixing process is typically done in a Vrieco Nauta mixer.


1) Cut tubing to proper length about 1/16 for each side of bead in addition to the width of the bead. Be sure to de burr the tubing before riveting. If the tubing splits when riveting it was cut too long. I buy my tubing from Rio grand and Metaliferous.
2) Place tubing between the die and anvil in the press and pull down on the lever until the top die flares the tubing. Make sure it flares it enough so that the caps or bead to be riveted will not fall off of the flared end.
3) Put bead or caps and bead on tubing with the flared end down back in the press. Repeat Step #2. Make sure both ends are flared evenly by placing the smaller end of the rivet pointing up in the press and pulling the lever making it larger.
4) Stop when the tubing starts to get tight. If you keep pressing the bead will chip or break.


== Conclusion ==
The tubing (rivet) is flared and it is ready to be set. What I mean by setting the rivet is that the silver tubing needs to be pounded down onto the caps or bead. This tightens the rivet so that the caps and tubing will not spin. Also it makes a nicer transition between the rivet and the bead, this will take some practice. You have to hit the rivet hard enough to get the silver to bend over and lay flat on the bead or cap. Too hard and the bead will be damaged, this is where the length of tubing comes into play. The right amount of tubing will be pretty easy to pound over but too much or too little is a real challenge. The thinner tubing it seems to be easier to bend over. Also going back over the ends of the rivet and polishing them will soften some of the sharp edges. Using small hammers and supporting the bottom of the rivet when pounding on the top seems to set the rivet nicely.
This is a process that will take some time and effort to master. Not only with flaring the rivet and setting it but also in making the correct shape of bead.
==Video==
==Video==
 
<youtube>SDU-6k4NmFg</youtube>
<youtube>cKZJbaN0Qew</youtube>

Latest revision as of 20:38, 7 August 2012


Batch Agglomerator

Agglomerators are used to increase the particle size of powders. They are very useful for powders of different particle sizes and/or densities that would otherwise seperate when handled. They are used when minor ingredients, often expensive ingredients, must be uniform throughtout a powder.

There are two basic types of agglomerators; compaction and noncompaction. The compaction type uses mechanical pressure (and often very high pressures) to "press" the powders together. For these, binders are sometimes not needed to make the particle. Compaction agglomerators are highly specialized, and not addressed here.

Any system that consists of at least one powder of any size, or mixture of sizes, and a liquid binder are agglomeration candidates.

Agglomerators keep the powders mixing while spraying a binding liquid. The binder is sprayed and then dries or sets or cures or otherwise hardens sealing the powders into a single bead. The need to keep the powders well mixed usually works against the idea of agglomeration. Mixers use high shear for mixing. This high shear also breaks particles down rather then agglomerates them. Ed O'Brien came up with the idea of a gentle mixing within his agglomerator in the 1960s.


Process

  1. The requested production capacities are normally in the range between 1000 and 4000 kg/hr.
  2. Process is always batch, with significant variations in recipes. This automatically results in easy and fast cleaning intervals geared to preventing taste and smell contaminations.
  3. The mixing process has to guarantee a low energy input per kg produced product, resulting in visually acceptable quality, without damaging components in the mixture.
  4. The complete process normally consists of two separate mixing processes. One is the intensive bulk mixing process (starch, salt, fat), the other is the gentle post mixing process of this bulk with the dedicated fragile specific soup components (vegetables, mushrooms, vermicelli, etc). The first intensive mixing process is executed in paddle or plough shear mixers, the second gentle mixing process is typically done in a Vrieco Nauta mixer.


Video