Frequently Asked Questions
Other paddle mixers us a different mixing method, typically to scoop off the bottom and throw over the top. There is not as much particle movement and products can roll apart.
Dividing the time into 60 will give you the cycles per hour. Divide that into the production and that will give you minimum but not usable size. To get to a usable size first divide by 0.8 to allow for inefficiencies, ingredient changes and interruptions. Then look at the hand-adds. If your recipe can accept bag weights, size up to remove the split bags. This is a judgment factor and it needs to be considered.
In some industries there is a minimum size or the labor for measuring ingredients gets out of proportion. If the size you calculate is not an industry standard, go up to the next standard.
Our mechanism cannot “drown” by loss of fluidization because that is not our mixing principle. So power is not a problem. The test where this 40% overload came from was done without an ammeter on the mixer, it was easy ingredients, (I have the study) and the Cv. ‘s were not reached within advertised mix time. There is some myth to the claim.
Our biggest concern would be the ability of the discharge to hold the material. “It depends” is common, but with fine powders I am quite certain their discharge would leak.
We use a minimum load torque to calculate what the power torque has to be, and in the door design all the deflections have to be less than the gasket compression or it will not hold powders.
If you are adding liquids, the system would be designed for the rated fill level. There has to be space to spray, and if you load in that space, the nozzles don’t have air resistance required to create a droplet.
Occasionally we get calls about overfilled mixers not mixing and what can we do. In some cases we can retrofit. All details have to be studied.
Roll apart segregation can be controlled by having the receiving container the same size as the discharge stream. The discharge can be a drop bottom or port as long as the receiver is sized correctly.
Elutrification has several medicines. Make your hopper no more that 1.3 x the batch size and limit the fall distance from a drop bottom. If the problem is even too severe for that, then control the discharge and run the material down a nearly vertical side (80 degrees) and make lots of opportunity for air to exit. Don’t overlook entrained air.
Also look at segregation exiting the hopper.
What we do is hold the door by torque from one or two air cylinders with constant pressure on the door, and it can move slightly to self-seat. The air cylinder crank is installed so the full stroke of the air cylinder is not used, and this additional travel compensates for gasket set. If there is build up on the gasket, it stops the air cylinder and when the build up is removed, it can adjust back to its original position.