Estimating Processing Times in a Row of Storage Tanks
The operation of tanks in industrial juice and other beverage processing has four stages: filling, holding, draining, and cleaning, whose durations depend on the particular product, the tanks' sizes, and the input and output flow rates. This Demonstration shows the operation of up to four tanks of equal capacity, where the liquid flow into and from the system is continuous and constant. You select the filling, holding, draining, and cleaning times of the first tank and repeat these parameters in subsequent tanks until each completes its cycle and is ready for reuse. A vertical dashed black line marks the time when the first tank is ready for refill. This determines the minimum number of tanks needed for the chosen cycle. A moving vertical orange line across the normalized volume versus time diagrams controls the appearance of the tanks in the schematic drawing.
Snapshot 1: a filling, holding, draining, and cleaning cycle requiring two tanks
Snapshot 2: a filling, holding, draining, and cleaning cycle requiring three tanks
Snapshot 3: a filling, holding, draining, and cleaning cycle requiring more than four tanks
This Demonstration generates four plots depicting the state of four tanks (a, b, c, d) being filled in succession, as shown in a schematic drawing on the left (valves included but pumps and controls not shown).
In the normalized volume-time plots on the right, diagonal lines represent filling or draining. A horizontal line at level 1.0 stands for a full tank (held for testing and/or contents adjustment). The other horizontal line, at level 0.0, stands for an emptied tank being washed and readied for receiving a new batch of product.
As shown by moving the vertical orange line from left to right with the "process time" slider, the operation starts with filling the first tank (a) at . When the first tank (a) is full, the second tank (b) is being filled and then the third (c) and fourth (d), assuming that the switching time is negligible. The filling, holding, draining, and washing times are chosen with sliders. The time at which the first tank completes its cycle and is ready to receive new product is marked by a vertical black dashed line. If the filling starting point of a tank (c or d) happens to coincide or fall beyond the time the first tank (a) has completed its cycle, the first tank (a) can be reused, that is, a smaller number of tanks would be sufficient for the particular cycle. This number is displayed in red below the four tanks' volume-time diagrams.
Moving the orange solid vertical line with the "process time" slider shows the state of each tank at any given time during the operation. The plotted process duration can also be set with the " axis max." slider.
The main purpose of this Demonstration is to show the role of a tank's cycle in liquid food and beverage processing. Therefore, not all the settings that it allows represent the operation of realistic industrial systems.