Page 366 - ExtendSim User Guide
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Tutorial for Discrete Rate Systems
A basic discrete rate model
yogurt were produced. This makes sense because, as the Results tab in the Merge block shows, the process produced about 30,000 gallons of yogurt.
At the end of the simulation run, holding the cursor over each outflow connector will show the final rate at that connector. For example, when the Yogurt Process has an effective rate of 72 gallons per minute, the Fruit Process will have a rate of 8 gallons per minute, the Mixing block will indicate that 80 gallons of mix were produced that minute, and the Change Units block’s output will show that 960 (80 * 12) containers of yogurt were packaged.
☞ This model assumes that the process of pouring yogurt into containers occurs at the same rate as the process of mixing the plain yogurt with the fruit. In this case, the packaging process does not slow down the rest of the process. To model a packaging process that would have an impact on the rest of the process, connect a Valve between the Merge and Change Units blocks and enter the appropriate packaging rate.
Cool the mixture
The yogurt process includes a 20 minute cooling phase on a 100-foot long refrigeration unit before the yogurt containers can be packaged into cartons. The Convey Flow block is designed to represent a delay in the movement of flow.
Delete the flow connection from the Change Units block to the Yogurt tank.
Add a Convey Flow block to the model and connect it between the Change Units block and
the Yogurt tank.
Notice that if you make these connections first, the correct flow unit (containers) is automat- ically selected in the new block’s Options tab.
In the Options tab of the Convey Flow block:
Select New Unit from the Length unit: length unit popup menu. In the dialog that
appears, enter feet.
In the Convey tab of the Convey Flow block:
Notice that the block is already set to Accumulating-maximum density by default. From the popup menu to the right of that popup, select the behavior Delay determines
travel time.
Enter Delay: 20 minute*.
Enter Maximum density: 500 containers/feet. Label the block Cooling Cycle.
Discrete Rate

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