Batch process Gantt chart

Figure 4.11 A Gantt or time-event chart of the batch process.

Figure 14.14 Gantt chart for a simple batch process.

Production schedules for batch processes can be sequential, overlapping, parallel, use intermediate storage, or use a combination of these. Such schedules can be analyzed using Gantt charts. Batch processes often produce multiple products in the same equipment and can be distinguished as flowshop or multiproduct plants. Equipment cleaning and material transfer policy have a significant effect on the production schedule. 

The values shown above the horizontal bars in the Gantt chart represent the quantity that is processed in a unit. In accordance with the formulation, Fig. 2.5 shows that the smaller the batch, the shorter the processing time in the same unit. The... 

Figure 10.1-10. Gantt chart for production scheduling of one batch of adenoviral vector. The top and bottom charts show the duration of each operation in the cell culture and downstream processing sections, respectively. The total process time is 405 hours. The arrow indicates the start of a new batch at 264 hours.

Be able to use the batch process simulators to cany out material and energy balances, and to prepare an operating schedule in the form of a Gantt chart for the process. 

To determine the cycle time and the bottleneck unit, create a multiple batch Gantt chart using BATCH PLUS. Generate equipment content and capacity reports to determine the sizes of the equipment items. Examine the stream table report to monitor the production of tPA-CHO cells and tPA in the process. 

Figure 4.27 BATCH PLUS simulation for Example 45. (a) Operations recipe for the process-BATCH PLUS output, (b) Last three columns of stream table (for the complete table, see ASPEN —> TutoM — Batch Process Simulation — tPA Manufacture on the CD-ROM. (c) Mixing Tank report (fa Fermenter 1 and 2 reports, see the CD-ROM), (d) 3-batch Gantt chart.

Finally, when the Gantt chart prepared by BATCH PLUS is extended to show three batches, as shown in Figure 4.27d, the bottleneck of the process is determined quite easily. For each vessel, solid blocks show the time period during which it is in operation. Solid blocks are for the first, second, and third batches, respectively. The bottleneck is associated with the equipment unit that is utilized at all times that is, for which the red, blue, and green blocks touch each other. Clearly, this unit determines the cycle time. Note that these results can be reproduced using the folder BATCH PLUS-EXAM 4-5 on the CD-ROM that accompanies this book. ... 

Figure 12.2 further shows us that in this case, the batch or lot is produced in a nonoverlapping way a batch is produced after the previous one has completed two batches cannot be manufactured parallel. It is of course also possible to simultaneously process the batches. The idle times are in such case eliminated as much as possible. Figure 12.3 shows the Gantt chart of an overlapping mode of operation. 

The addition of parallel units can increase the efficiency of the plant considerably. Let us consider a simple biorefinery that is operated in zero-wait mode. Each batch is the same (1000 kg). In the first stage, the biomass is converted in a bioreactor to ethanol, which takes 12 h. In the second stage, a distillation is performed to pnrify the bioethanol. This separation step takes 3 h. The Gantt chart of the process is depicted in Figure 12.5. It is obvious that the CT for each batch is 12 h. 

The information on operation durations and scheduling links is translated by the tool into a Gantt chart that enables users to visualize a batch process. Figure 15.10 displays the Gantt chart of the recipe described above. The bar at the top repre-... 

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