Fill rate, containers per minute, SPEED. This is the main question asked about a filling line. While it appears a straightforward question, many variables impact the fill rate. The most obvious variables are fill rates, dribble and convey speed. Proper nozzle selection will allow splash-free filling at high rates. Further improvements can be achieved by establishing dribble weight to a minimum level that will still consistently deliver the desired accuracy. Increasing conveyor speed will also improve filler throughput. For these variables, product viscosity plays a major role. A thin product may splash or foam and if filled close to the top of a container can spill as the container leaves the filling area. A slightly more viscous product may allow for quicker filling and transport. That is why it is important to understand the product viscosities, container sizes, container types and fill levels.
Even once these times are set, many other time-consuming operations occur during the filling cycle. While these operations may only be a fraction of a second, they can have a large impact on performance. Some of these delays are optional, others are required to perform a physical task. For automatic machines, it is important to isolate the container from vibrations caused by the moving conveyor. Typically, the scale is lifted, raising the container off the moving conveyor. At the end of the fill cycle, the scale must be lowered to allow the container to be conveyed from the fill zone. In the case of sub-surface filling, time is consumed for the lance to travel to the bottom of the empty container and to be removed from the filled container. Beyond these, there are other pre-fill and post fill delays. Pre-fill, we may wish to test that a container is in-place before opening the fill nozzle. To do this, we impose a slight delay to allow the scale to settle and ensure a minimum weight is present on the scale to account for the container, or we may wish to get a more accurate tare weight for record-keeping purposes. Post-fill, we may impose delays to allow the last of the product to drip from the nozzle or to get a final check-weight. Together with conveying, these non-filling operations can account for 40% to 70% of the total fill time.
DisperseTech Filler Performance Calculator demonstrates the effects of operational timing including supply rates, dribble settings, conveyor configurations and speeds and delay settings. In response to your selections, the tool calculates fill rates in gallons per minute and containers per minute as well as the percentage of time spent in filling and non-filling operations.