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.

Food and Beverage Case Studies

Case Study 115: Oven Control Baking Industry Sector: Food and Beverage • Cake Machine

Technology Replaced:

  • Old VFD System

New Technology Applied:

  • Allen Bradley SLC 500
  • Allen Bradley PanelView
  • Allen Bradley VFDs

Project Description:
Staneco Corporation was approached to design a system to control a multi-layer cake baking machine. The machine consisted of multiple conveyors which produced a continuous baked cake. The operator entered the number of cakes per minute required. This number was used to calculate the speed of the conveyors, which determined baking time by changing the transit time through an oven. The speed information was sent to multiple VFDs to change the speed of conveyors. The speed control had to be accurate enough to prevent the tearing or bunching of cake as it transitioned between conveyors and as the multiple layers were brought together. VFDs with feedback were used to obtain the required accuracy. The cake was then delivered to a cutter to divide the cakes into the correct size.

Project Outcome:
The old VFD system was hard to adjust since each VFD needed to be individually adjusted. With the new system, VFDs were adjusted based on operator’s input which allowed for less downtime when the line was changed for different products. As a result, a significant increase in product throughput.

Environmental Case Studies

Case Study 118: Scrubbers Industry Sector: Environmental • Stack Emission Control System

Technology Replaced:

  • Square D 784 PLC System

New Technology Applied:

  • Modicon Quantum Redundant System

Project Description:
Staneco Corporation replaced outdated PLCs with new Redundant Modicon Quantum PLCs for air pollution and dust collection equipment at a power plant. The system was programmed utilizing existing loop drawings along with additional input from client’s engineering staff. The hardware was replaced in a manner which allowed for minimum down time. The existing field wiring was unchanged. Because the new PLC equipment was so much smaller than the original, Staneco came up with a design that added terminal blocks in the same physical locations as the original I/O. These terminals were located on sub-panels along with the new PLC hardware. The terminals were wired to the new PLC I/O. The entire assembly was installed on the existing panel. When the old I/O was removed, the original field wiring was landed back on the new terminals without disturbing the field wiring. This allowed the change to be made in the short outage window.

Project Outcome:
Since the old PLC hardware was obsolete and replacement hardware becoming harder to obtain upgrading the system was essential to the plant’s operation. The new system provided additional fault monitoring and greater data collection making the process easier to troubleshoot and monitor.

Case Study 130: Gas Recovery System Industry Sector: Environmental • 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 102: Stack Emission Control Industry Sector: Environmental • 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 103: Scarfing Industry Sector: Environmental • Scarfing / Crusher Conveyor System

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 104: Air Pollution Controls Industry Sector: Environmental • Regenerative Thermal Oxidizers

New Technology Applied:

  • Siemens Simatic S7-300
  • Siemens Simatic HMI MP 277

Project Description:
Staneco designed controls for two thermal oxidizers used for treatment and abatement of malodorous emissions at a waste treatment facility. The oxidizers consisted of multiple gas burners which heated combustion chambers containing ceramic pellets. When the process gas was 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 which re-circulated the untreated gasses. Temperatures and operation of the valves was monitored and alarmed.

Project Outcome:
Malodorous emissions were eliminated meeting local requirements.


Case Study 109: Air Pollution Controls Industry Sector: Environmental • Carbon Dioxide Recovery System

New Technology Applied:

  • Siemens PCS7

Project Description:

Staneco Corporation designed an experimental control system for a government study to remove carbon dioxide from a coal fired power plant stack exhaust. The system controlled the flow and temperature of amines to absorb and release the carbon dioxide.

Project Outcome:

Various types of amines were tested to find the most effective.

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.

Machine Control Case Studies

Case Study 101: Servo Industry Sector: Machine Control • Fiberglass Fiberization

New Technology Applied:

  • Allen Bradley ControlLogix
  • Allen Bradley Servo Drives
  • AMCI Encoders
  • Rockwell RSView32 SCADA System

Project Description:
Staneco Corporation designed a fiberglass insulation machine which operated faster and more efficiently than the old equipment. Four fiberizer units deposited fiberglass on a moving conveyor. Any three could be used or all four depending on the type of insulation being made. The fiberizers were pivoted and deposited the fiberglass in a sine wave pattern. The pivot speed and conveyor speed were all adjustable depending on the product and stored recipes. To make uniform fiberglass, the pattern on the conveyor had to be adjusted. The phase angle of each pivoting fiberizer had to be calculated (frequency of pivot and conveyor speed both affect the phase angle). The information was used to control servo motors which controlled the motion of the pivot.

Project Outcome:
The key to successful resolution of this process problem was deciphering the complex relationship between belt speed and controlling the deposition sine wave of the fiberizer. The result was improved consistency, quality of product, and higher production rates.

Case Study 114: Extruders Industry Sector: Machine 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.

Case Study 110: Blending Industry Sector: Machine Control • Alloy Blending Machine

Technology Replaced:

  • Obsolete Relay Panel

New Technology Applied:

  • Allen Bradley MicroLogix 1500
  • Allen Bradley PanelView
  • AMCI Stepper Motor

Project Description:
Staneco Corporation designed controls for a machine that produced alloys in small batches. There were 20 recipes for different alloys. The cycle started by purging the chamber of air followed by gases being introduced into the chamber. The metal was heated to the required temperature by an induction heater. When at temperature, the crucible was then tilted in steps at different speeds using a servo motor to pour the metal into a mold. The crucible was then returned to the home position and atmospheric pressure was re-introduced. Temperatures were recorded on an electronic chart recorder.

Project Outcome:
The new control system provided increased reliability along with a more efficient operator interface.