Estimated Auger Delivery Calculator
What are your product flow characteristics?
Free Flowing (FF) (salt, sugar, rice, whole bean coffee)
If your product definitely has free flowing characteristics, you will use a straight auger with a spinner plate and a straight funnel. In addition, you will utilize a collector funnel assembly. The straight auger has consistent diameter flights throughout, this is because the product does not need to be compressed in order to achieve good accuracy. The free flowing product easily falls (gravity) into the auger flights and it is easy to meter. The spinner plate is needed at the bottom of the auger because it holds the product up, remember it is free flowing, so without the spinner plate the product would run right through the auger flights. The spinner plate’s height should be set at a happy medium so that product is cut off from flowing past it, but also restricted enough to gain good volumetric filling accuracy. As the auger turns, product is thrown from the spinner plate and contained within the collector funnel. The collector funnel allows for the product coming from the spinner plate to collect and drop through any diameter tube for tight discharge. Of course, each application is different, so always consult with All-Fill first before running product.
Non-Free Flowing (NFF) (pancake mix, ground coffee, flour)
If your product definitely has non free flowing characteristics, you will use a self-feeding auger (compression) and a lip funnel. The self-feeding auger has “over flight” at the top. The over flight of the auger is larger than the straight section of the auger which is housed within the funnel. The overflight of the auger is completely exposed to the contents of the hopper. The purpose of the over flight is to grab the non free flowing product and compress it as much as possible and convey it into the straight flights. It is simple, the more packed the flights of the auger are, the better the accuracy is. If the flights are loose, not tightly packed, the accuracy will not be as good. The lip funnel used with non free flowing products has a small lip welded to the inside of the funnel tube. The lip is designed to create back pressure when the product is filled and keep the product from dripping out. The bottom of the auger, the last flight, should be set just above the lip of the funnel. Typically, this is 1/16″ or the thickness of a fingernail.
In between “Tweener” (product has both FF and NFF characteristics)
All products that fall in between free flowing and non free flowing should most certainly be evaluated by All-Fill. These products are often filled with straight or self-feeding augers. Regarding a funnel, typically these products necessitate the use of a positive cut-off device. A positive cut off device ensures that there is no leak or drip after the fill cycle is complete. There are no rules when dealing with “tweeners.” For that matter, there are no rules when it comes to auger filling, All-Fill always likes to evaluate sample product.
Is the product Dusty?
If so, we would highly recommend a dust shroud attach to the funnel. Dust shrouds are designed with a dust take off port which allows the user to hook up a vacuum. A dust shroud can be used with free flowing or non free flowing products. If filling a free flowing product, a dust shroud is critical because the product is falling from the spinner plate. If filling a non free flow product, the dust shroud may still be needed but it is perhaps less important because you will most likely have the opportunity to bottom up fill. A bottom up fill means that the rigid or flexible container is lifted up to the dispensing funnel, as the fill process takes place, the rigid container or flexible pouch is pulled away from the dispensing nozzle. This helps to keep the dust down as the nozzle is engaged.
In order to determine Product Density…
a) Find an offline scale, and tare the weight of a 1000 mL graduated cylinder. If you do not have a 1000 mL graduated cylinder, use a smaller one and be sure to divide the 1000 mL by the size of the cylinder that you are using to find the multiplier you will need to use in order to find the weight of 1000 mL (see step: “d” below).
b) Fill a 1000 mL gradulated cylinder with your product. Do not tap it or vibrate it, level it off with your finger.
c) After the cylinder is filled, weigh it on the same scale for which the cylinder has been tared.
d) Multiply the weight of 1000 mL of product by .062427. This will give you the product density in lb/ft3
e) Based upon the determined product density found in step: “e”, use that figure in lb/ft3 to determine what type of auger is needed to dispense your product in accordance to the fill size and rate that you want. Depending on the size of the auger selected, the funnel may be matched to the auger size or we could recommend a size(s) of clearance between the OD of the auger and the ID of the funnel. The clearance is recommended so that the product is not crushed or degredated.
f) All-Fill typically likes to turn the auger between 3 and 5 revolutions of the auger in order to fill to your target weight. Take your desired fill weight and divide it by 4, to determine grams per revolution. It is often wise to take your product density and subtract about 5 lb/ft3 to use as your density figure. This is taken into consideration because product will not always feed to the auger with 100% efficiency.
Of course, the information provided here is informative only and is anything but absolute. Please always contact All-Fill with application questions!