USP Water Purification/Batching System
SUMMARY: Replaced the existing control system on a pharmaceutical USP water purification system with a new PLC/MMI based system allowing password security and access, operator interface for setup, process parameter configuration and alarm annunciation. System controls monitored various quality devices (rupture disks, filter pressures, temperature and UV status) as well as conductivity and TOC.
DESCRIPTION: The process takes incoming city water, purifies it through various filter beds, UV treatment, and sub-micron particle filtration to make USP grade water for manufacturing pharmaceutical products. After the water is cleaned, it is stored in a reservoir that maintains constant water circulation. Operators select a destination tank, batch size and dispense temperature, and the system will dispense the correct water volume at the correct temperature. Various control parameters are entered into displays that provide upper and lower control limits for various system analog devices. The system is completely self-monitoring, and when a problem is determined to exist, the system will disable various processes (Rinsing, Batching and Sanitizing) until the problem is corrected and acknowledge. All system events are archived, and the archive is periodically offloaded onto a ZIP disk for long-term storage. Data may be reviewed from the Operator Workstation by specifying date and time delimiters.
Waste Water Treatment Control System in a Manganese Manufacturing Chemical Plant
SUMMARY: Develop and install a PLC/HMI controls system for the complete Chemical Neutralization process of the plant waste materials.
DESCRIPTION: The PLC monitors the level, pH, ORP, turbidity and temperature of the 25,000 gallon process tanks. Agitation time, flocculation time, aeration time and settling time are all controlled from the PLC. The system is designed to add anionic polymer, cationic polymer, lime and acid at proper proportions and proper phases throughout the staged process. The PLC controls all of the process valving and pumping as the waste gets transferred through the various wash tanks, surge tanks, sand filters, filter press and outfall. The operator station (HMI) graphically depicts the process and display complete process status, timers, setpoints, flows, levels, pH, turbidity, temperatures and totals. Additionally, the operator can view the process from the real-time or historical trend screens for any of the parameters. All system faults are alarmed, recorded and displayed on the operator station.
Gas Fired Fluidized Bed Dryer Controls for Cement Industry
SUMMARY: Developed a 2 burner, 2 Zone combustion control and feed control system for a Gas Fired Fluidized Bed Dryer.
DESCRIPTION: The PLC monitors and maintains zone temperature setpoints by controlling the combustion air fan and gas valves. The system continuously monitors interlocks for safety and shutdown circumstances. Each zone has fuel valve and combustion air PID control to allow smooth start-up and shut down. Logic was developed to allow Bumpless transition from automatic to manual control. The cement feed rate is controlled to maintain dryer bed temperature while the cement discharge valve is controlled to maintain dryer bed level. The operator has complete manual and automatic control of the system through the graphical HMI. All alarms and events are recorded to a database and displayed as they occur. Logic is incorporated to monitor PLC input and output modules for failures.