Process Control Case Studies
Case Study 105: Polymer Process Industry Sector: Process Control • Polymer Process Machine
New Technology Applied:
- Allen Bradley ControlLogix
- Allen Bradley PanelView Plus HMI
Project Description:
Staneco Corporation designed a control system for polymer mixing machines. Polymer is used in the process to remove particles from both drinking water and treated sewage. The system involved monitoring the level of a polymer tank. When the level dropped to a pre-determined point, a new batch of polymer was added. First water was added to a mixing tank to a pre-determined level. When the tank reached this level, a polymer powder was weighed and added. As the powder was added, a mixer started blending the water and polymer. The pre-determined polymer concentration was calculated. The mixture was then sent to a second mixing tank where more water was added to get the polymer concentration down to the required level. Finally the polymer was pumped into the final polymer tank. The system was set up to operate in two modes, demand batching and bulk batching; each having different control characteristics.
Project Outcome:
System allowed for customization of recipes enabling quality control of the product. HMI alarm indication reduced operator error and increased the machine life cycle.
Case Study 114: Batching
Industry Sector: Process Control • PVC Compounder System
Technology Replaced:
- Relay Panel
New Technology Applied:
- Allen Bradley SLC 500
- Allen Bradley PanelView
Project Description:
Staneco Corporation designed a control system to produce batches of compounded PVC. The system automatically weighed out batches of PVC resin and calcium carbonate. The material was conveyed with a pneumatic conveying system into a compounder drum. The drum was rotated and heated with the temperature being monitored. A liquid stabilizer and additional chemicals were automatically added to the mix when the temperature reached predetermined temperatures. At the end of the cycle, the material was unloaded into a cooling drum until it was cool enough to be transported into a storage silo. The material was then automatically distributed to several lines of extruders based on demand from the extruders.
Project Outcome:
The new control system eliminated repeat failures which were greatly impacting production and quality.