Testing and Sampling Case Studies

Case Study 130: Gas Recovery System Industry Sector: Testing Equipment • Gas Recovery System

New Technology Applied:

  • Allen Bradley SLC 500
  • Allen Bradley MicroLogix 1500
  • Allen Bradley PanelView Plus
  • Rockwell RSView32 SCADA

Project Description:
Staneco Corporation designed a control system that purified contaminated ground water. The system consisted of three wells. Water was pumped from two of the wells.  Flow from the wells was monitored.  The flow rate could be regulated either by fixed flow rate or by monitoring the level of the wells and adjusting the flow to keep the level of the wells at a fixed setpoint. The operator selected the desired method of control. A chemical was added to the water and it was pumped back into a third well. The flow rate of the chemical was paced to the flow rate of the water.  Data was collected which included well levels, water flow, and chemical flow. The data was stored in Excel format.

Case Study 127: Platinum Recovery Industry Sector: Testing & Sampling • Platinum Recovery System

New Technology Applied:

  • AB SLC 500
  • AB PanelView Plus

Project Description:
Staneco Corporation designed a control system to process discarded catalytic converters to collect the Platinum for resale. The installation provided the user with the ability to automatically start the line in production mode, controlling the delivery of the pre-crushed material to the Hammer Mill to optimize the loading of the unit. In addition, complex calculations were incorporated in the control system to perform lot size and sample size requirements for a given order. The system then monitored the weight of the accumulated lot and automatically shut the system down when calculated weight was reached. Other functionality included was:

  1. Maintenance alarms for individual system components based on hours of operation and the amount of processed material processed.
  2. Real time and historical trending for key variables of the process.

A second process train was added to the original system to allow the user to optimize system utilization and limit the downtime to a minimum. This addition incorporated hardware and control strategies to provide the ability to process two lots of material at the same time, thus maximizing the throughput of the system.

Project Outcome:
Enabled the customer to maximize the production capabilities of the installation and provide the ability to effectively schedule operating personnel to limit operations dead time.

Case Study 112: Automated Testing Industry Sector: Testing & Sampling • Hardness Testing Machine

New Technology Applied:

  • AB SLC 500
  • AB PanelView Plus

Project Description:
Staneco Corporation designed an automatic machine that tested the hardness of railroad wheels. The wheels were of different sizes and with different model numbers. The information about the wheels was received from a DCS system. The DCS provided data on wheel diameter, model number, serial number, along with the minimum and maximum allowable hardness ranges. When the wheel arrived at the testing machine, the machine head was lowered into position. A mill was used to clean the surface of the wheel to be measured. The hardness head was then engaged. When the hardness was determined, the value was sent to the PLC serial port as ASCII characters. The ASCII characters were evaluated to determine the hardness number. If the value was in range, the part was passed and sent out. If the hardness failed, the wheel was retested a second time. If the wheel still didn’t pass, it was marked with paint and sent out as a reject.

Project Outcome:
By adding this system to their production line, the end user was able to guarantee product quality and maximize profitability.

Case Study 116: Pressure Vessels Industry Sector: Testing & Sampling • Repeater Pressure Testing Control System

New Technology Applied:

  • Allen Bradley SLC 500
  • Rockwell RSView32 SCADA System

Scope of Work:
Staneco Corporation designed a control system to do high pressure testing for Trans-oceanic fiber-optic repeaters. The repeaters were put into a high pressure vessel. The outside of the vessel was pressurized to 10,000 PSI with a mixture of air and helium. The inside was monitored using a helium leak detector. Multi-stage pumps had to be used to attain the required pressure; this pressure had to be held for a selected time. Since the plastic content in the repeater could be damaged if the pressure changed too quickly, the pressure had to be reduced over several hours.

Project Outcome
By utilizing the new control system, repeaters could be tested more quickly allowing production to meet increased sales demands.

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.

Burner Management Case Studies

Case Study 122: LNG Industry Sector: Burner Management • 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 108: Ovens / Dryers Industry Sector: Burner Management • Conveyor Dryer

New Technology Applied:

  • Allen Bradley CompactLogix
  • Allen Bradley PanelView Plus HMI

Project Description:
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 102: Stack Emission Control Industry Sector: Burner Management • 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.

Case Study 121: Ovens / Dryers
Industry Sector: Burner Management • Ceramic Sintering Furnace

New Technology Applied:

  • Allen Bradley CompactLogix
  • Rockwell RSView32 SCADA System

Project Description:
Staneco Corporation designed a sintering oven to produce special purpose ceramics. The process was temperature and time dependent. There were numerous recipes for the different ceramic products produced. The temperature of the furnace was ramped up over a predetermined time to a selected temperature. At various temperatures different gasses were introduced into the process. The flow rate had to be controlled. When the maximum temperature was reached, it was held for a selected time. The temperature was then ramped down once again controlling the gas flows. Since one of the gasses was hydrogen, special interlocking and monitoring had to be used to prevent dangerous situations. The gas flows and temperature over time were logged and put into an Excel file for record keeping and examination. The cycle typically lasted from 12 to 16 hours.

Project Outcome:
Client praised the flexibility of the new system and its enhanced data collection abilities resulting in improved quality control.