Conveying Case Studies

Case Study 103: Bulk Industry Sector: Conveying • Scarfing / Crusher Conveyor System

Old Technology Replaced:

  • Antiquated Relay Panel

New Technology Applied:

  • Allen Bradley MicroLogix
  • Allen Bradley Component HMI

Project Description:
Staneco Corporation designed a crusher conveyor control system to replace an existing relay panel. The system consisted of conveying material through a series of conveyors and hydraulic crushers. Crushed material was then conveyed and separated by size and conveyed to different piles. Speed of the conveyor was controlled by VFD based on operator input. Safety interlocks were applied to prevent any possibility of injury. The system was able to operate in automatic, remote and manual modes. HMI displayed alarm conditions and location of fault events.

Project Outcome:
The combination of the PLC and HMI provided a more modernized system which increased throughput and minimized downtime while meeting all safety requirements.

Case Study 106: Pneumatic Industry Sector: Conveying • Pneumatic Conveying Systems

New Technology Applied:

  • Allen Bradley ControlLogix
  • Allen Bradley PanelView Plus

Project Description:
Staneco Corporation designed controls for multiple baghouse systems and hydrated lime injection systems used at multiple coal-fired power plants. The hydrated lime system had multi-point injection points and was used with fluid bed boilers. Hydrated lime is a proven alkaline reagent used to remove SO3 from the flue gas. Both pressurized and vacuum conveying was implemented. Blower motors, feeders, and rotary airlocks were controlled and monitored. Alarm conditions were monitored and control interlocks utilized allowing the system to operate safely.

Project Outcome:
Systems provided an effective and cost-efficient way to reduce emissions from the fluid bed boilers. The use of control interlocks and alarm monitoring kept the systems operating safe and increased the equipment’s performance.

Case Study 108: Manufacturing Industry Sector: Conveying • Conveyor Dryer

New Technology Applied:

  • Allen Bradley CompactLogix
  • Allen Bradley Panelview Plus HMI

Project Description Applied:
Staneco Corporation designed a PLC panel with burner and motor controls for an industrial dryer. The drying process consisted of several stages which were heated by natural gas burners. Each stage had exhaust and combustion blowers which were started automatically by the PLC. The burner ignition was controlled by Honeywell flame relays. The material was carried through the dryer by a conveyor with VFD speed control. The temperature of the dryer stages was controlled by PID control loops in the PLC.

Project Outcome:
The ability to monitor many variables and store product recipes allowed for greater quality control and increased throughput.

Case Study 113: Material Handling Industry Sector: Conveying • Material Handling System

New Technology Applied:

  • Allen Bradley ControlLogix
  • Allen Bradley PanelView Plus HMIs

Project Description:
Staneco Corporation designed a system to deliver 400 to 1600 pound rolls of paper to printing presses using an in-floor chain conveyor. The system consisted of carts holding rolls of newspapers that traveled through the press room until a press operator needed a roll of paper; at which time the operator pressed a button diverting the new roll to the press. At the press the roll was removed, the empty cart detected and sent back to an area where it could be refilled. Filled carts were automatically merged back onto the main line. Special carts were used to remove waste such as the roll covering and empty spools. Full waste carts were diverted to the waste area, emptied, and automatically merged back to the main line. The critical functions included controlling the cart stops at the merge area and implementing a shutdown if a collision was about to occur at the merge point.

Project Outcome:
The implementation of the system reduced cart collisions thereby increasing operational safety and allowing quicker reloading of the presses.

Energy Case Studies

Case Study 122: LNG Conversion Industry Sector: Energy • Vaporizer Control System

Process or Machine Automated: submerged combustion vaporizer control systems

New Technology Applied:

  • GE Fanuc 90-30 series PLC
  • GE QuickPanel HMI
  • Wonderware Intouch SCADA

Project Description:
Staneco Corporation designed controls for multiple liquefied natural gas vaporizers for use in a re-gasification process at a peak shaving facility. Each vaporizer contained a large burner that heated a water bath for the evaporation process. Two PLC systems were utilized for control of each vaporizer; one system for burner management as required per the NFPA and one system for other process controls. All units had automatic ignition and bath temperature control. In addition to the gas control required to operate under normal conditions, interlocks were added to safely handle alarm conditions. Each control system provided feedback to the plant DCS.

Project Outcome:
The addition of these peak shaving units enabled the plant to meet the critical requirements of peak consumption periods. Operators praised the ease of use provided by the control system and the ability to make adjustments to ensure optimal performance.

Case Study 102: Ethanol Plants Industry Sector: Energy • Regenerative Thermal Oxidizers

New Technology Applied:

  • Allen Bradley CompactLogix
  • Allen Bradley PanelView Plus HMI

Project Description:
Staneco designed controls for two thermal oxidizers used at a corn-to-ethanol plant to remove organic chemicals from discharged air. The oxidizers consisted of multiple gas burners which heated combustion chambers containing ceramic pellets. When the process gas is passed through the pellets, the organic chemicals are oxidized, neutralizing them. In order to prevent overheating of the ceramic pellets, a series of dampers were switched based on either time or chamber temperature. As the chambers were switched, some gas escaped unprocessed. To remove these gases, a purge operation was included to re-circulate the untreated gasses. The motors were controlled over Devicenet which included two VFDs. Temperatures and operation of the valves are monitored and alarmed. Data was made available to the plant DCS system.

Project Outcome:
System met and exceeded the required emission acceptable limits. The process also helped minimize fuel consumption.