ITAC installs control system at tobacco company | Automation.com

ITAC installs control system at tobacco company

May 172012

May 17, 2012--The U.S. tobacco industry remains robust, with demand for premium cigarettes growing in increasingly affluent countries in Asia and Eastern Europe. In fact, more than 60 percent of American-grown tobacco goes overseas, according to the U.S. Department of Agriculture.

But before it’s shipped to foreign markets, tobacco fresh from the fields must be processed. It is, after all, a perishable crop. That’s why major cigarette makers – based both here and abroad – locate their processing plants conveniently close to tobacco farms, which continue to flourish in Southern states like North Carolina, Kentucky and Virginia.

In 2010, one of the world’s largest cigarette manufacturers completed construction of a new tobacco-processing plant in the Mid-Atlantic region. The project posed unusual challenges for systems integrator ITAC – Industrial TurnAround Corporation – based in Chester, Va. Despite ITAC’s extensive experience with the tobacco industry, the deadline was daunting – just 16 weeks to engineer, design and build a system that would process $1 million of tobacco every day from September to April. 

ITAC lived up to its name as a speedy integrator, completing the project on-time and on-budget. A major factor in this success story was ITAC’s longstanding relationship with Rockwell Automation.

“We were confident that we could meet the tobacco company’s aggressive deadline if the project was based on a Rockwell Automation solution,” said Mike Jones, manager, Electrical and Controls, ITAC.  “Our engineers have more experience with Rockwell Automation than any other supplier. Our Rockwell Automation partners jumped into this project and worked with us all the way to the finish line.”

Challenge

The engineers at ITAC knew about the project months before they were hired for the job. They had been contacted in February 2010, and asked to bid on the design and installation of processing equipment for the plant. Originally, the plant’s specifications were based on another automation company’s products and solutions.

While ITAC had come highly recommended, the tobacco processor instead chose an engineering company based in Italy. But the tobacco processor and the Italian company, in the words of Jones, “Couldn’t come to terms.” So eight weeks after its initial bid was rejected, ITAC got a call from the tobacco processing company, asking ITAC to take on the project – still with the original August deadline.

“The tobacco company would not come off that end-date because they had contracted with local farmers to process millions of dollars worth of tobacco,” Jones explained. “Those bales were going to start piling up at the doors of the plant in just 16 short weeks.”

Jones and the ITAC team decided to take on the project, despite a stipulation in the contract that would require the company to pay $3,000 per day in damages if it was responsible for missing the original deadline.

After days of negotiations and the client’s decision to change to a Rockwell Automation solution, ITAC agreed to the schedule and terms, feeling their vast experience and support, the Rockwell Automation team gave them a great opportunity to achieve the client’s goals and meet the contract deadline.

“We knew we could make the date if Rockwell Automation was the single automation solution provider,” said Larry Justesen, senior controls engineer, ITAC. “All of our designers are experienced with the product line. We had Rockwell Automation templates for panel layouts. The local people who would be maintaining this equipment are all familiar with Rockwell Automation, so everything pointed to them.”

The tobacco processor agreed to go with Rockwell Automation as the supplier, and the two parties came to terms on a Friday afternoon. Jones worked all weekend, using ProposalWorks software from Rockwell Automation to put a new bill of materials together. First thing Monday morning, Jones called his local Rockwell Automation distributor to discuss the details. The distributor quickly tapped Rockwell Automation product managers to help expedite pricing approvals, confirm product availability and hammer out the remaining details of the contract.

“This was not your typical job in any sense of the word,” Jones said. “Typically, you do the engineering before you order the parts. This was the reverse.”

The deal was signed on Thursday, and ITAC instantly put in a purchase order for half of the materials, including $800,000 worth of hardware. “We also contacted the panel shop and got them onboard with the project so they could fabricate and deliver thirty-six panels in a phased approach – about five panels a week over a seven-week period.”

Solution

Meanwhile, the designated site of the tobacco processing plant was an empty, five-acre warehouse. Come fall, this shell would be filled with the sticky sweet smell of tobacco, as farmers from across the area dropped off bales weighing 400 to 500 pounds each. These bales would fill up two-thirds of the warehouse. The rest would contain the workers and the machines to convert the crop into an international commodity.

Processing raw tobacco requires four separate stages: blending and picking, threshing, drying and packing. Once the raw bales are loaded onto a conveyor belt, every part of the process is automated.  First the bales travel to a silo – essentially a huge rectangular bin – where the tobacco is chopped up by a huge hydraulic slicer.

Plant workers stand along “picking lines,” examining the tobacco as it streams out of the silo on a conveyor belt. The workers look for any unwanted remnants from the harvest – such as cardboard or baling wire – that must be removed before the tobacco moves to the threshing process.

Threshing separates the more valuable leaf material from the stems. Within the threshing cylinder, large mechanical teeth chew up the plants. Steam is also applied to help “condition” the leaves to open up and become fluffy, allowing the stems to be more easily removed.

From here, the leaves and stems take different paths through a similar process – they’re separately dried and then packed into cardboard boxes, each weighing around 400 pounds. The clean, compressed tobacco is then ready to be shipped overseas, where it provides the raw material for cigarette manufacturing.

“As it goes into the boxes, the leaf tobacco looks like what you would see in a cigarette, but not quite so finely cut,” Justesen said.

To manage each of these four stages, ITAC selected the PlantPAx process automation solution from Rockwell Automation, which leverages the Allen-Bradley ControlLogix programmable automation controller. Unlike conventional controllers, it handles the plant’s sequential and motion control movements, eliminating the need for a separate motion controller and associated wiring for each function. The ControlLogix controller also handles the process loops needed for steaming the leaves, eliminating the need for loop controllers. This integrated control platform helped ITAC design the program using a single development environment – which proved to be an essential, time-saving element for this project.

To stay on deadline, ITAC subdivided the programming into four teams – one for each of the four stages of the process. To program a control system, different programmers commonly work on the same application simultaneously. But this concurrent engineering strategy can cause overlap and programming inconsistencies. For example, if one programmer sees an available memory cell, it could already have been allocated for a different purpose.

The RSLogix programming software for the ControlLogix platform completely insulated ITAC’s programmers from worrying about memory. The availability of isolated data scopes allows multiple programmers to use the same variable tag names. As long as the tag names are in different data scopes, the information will not collide. Additionally, programs written by multiple programmers can be merged together without having to rename the local variable names.

Leveraging the Rockwell Automation sample code library – which includes pre-tested modules of code for common design approaches and applications, ITAC’s engineers were able to minimize errors and deliver a consistent look-and-feel.” Using pre-built modules to control valves, motors and other equipment greatly reduced our programming time, as well as the time we spent modeling each run,” Justesen said. 

While the reuse of code helped streamline programming, ITAC also specified several design strategies to help speed up the process of building panels. “Knowing that we were going with a single supplier – Rockwell Automation – we were able to create a good base design for the panels,” Jones explained.

ITAC leveraged the Allen-Bradley Drives and Motion Accelerator Toolkit, which includes a variety of tools and templates to help reduce drive design, installation and integration. The toolkit includes a preconfigured panel layout, wiring and human-machine interface (HMI) faceplates, preconfigured logic required for the HMI faceplates, and provides common application logic examples to get the system up and running quicker. ITAC used two drives in its panels – the Allen-Bradley PowerFlex 40 and 753 AC drives. The PowerFlex drives are equipped with highly configurable I/O including the ability to perform basic logic, timer and counter functions. Performing these functions at the drive instead of a controller significantly reduced wiring.

Other elements helping ease panel design time included DeviceNet cable accessories and IEC motor starters with E3 overload relays from Rockwell Automation. Motor Starter Panel power distribution was developed using Rockwell MCS™ Star Software which fed a bill of materials to ProposalWorks. The DeviceNet cable and multi-port taps integrated eight nodes to the DeviceNet trunk. The distributed I/O architecture helped the panel builders get a jump start on wiring, while the DeviceNet Quick Disconnect helped ensure easy installation after the panels were delivered. The Allen Bradley 193-EC5 E3 solid-state overload relay, meanwhile, combines current and voltage protection with enhanced power monitoring and diagnostic capabilities, helping save time and safeguard critical electric motor loads.

The panels were also equipped with FactoryTalk View Supervisory Edition visualization software and 16 Allen-Bradley PanelView operator terminals to provide a window into the process and enable operators to adjust thresher set points as needed. The HMI panels were connected via an EtherNet/IP fiber ring and copper switches to several industrial computers for operation and maintenance tasks. As FactoryTalk View supports the creation of direct tags, programmers accessed definitions directly from the controller and referenced the appropriate tags by name. This eliminated the need to cross-reference controller physical memory or perform import/export, while reducing the development effort and number of errors.

While no MES-level software was part of phase one, the end user specified a redundant server system for data collection – with six clients on the floor for the individual engineering work stations.

Each week, ITAC had five control panels delivered to the job site – with the last five panels arriving two weeks prior to the tobacco processor’s installation deadline. This allowed time for final wiring and troubleshooting.

Results

Weekly conference calls about hardware deliveries, ongoing discussions to coordinate installation priorities and a committed supplier helped ITAC meet its delivery obligations.

So did ITAC’s deep experience with Rockwell Automation. Over the years, ITAC engineers have attended training sessions on Rockwell Automation’s solutions and toolsets. “Based on the aggressive schedule, it was either Rockwell Automation or nothing because of our longstanding experience and relationship with them,” Jones said. ”This system was programmed and integrated faster by leveraging blocks of pre-tested code, distributed I/O and the Rockwell Automation portfolio of development toolkits – all created to help system integrators like us who are in a time crunch.”

ITAC’s success in executing the project convinced the tobacco producer to continue working with the systems integrator well beyond the initial start-up phase to allow for tweaks and improvements to optimize the factory’s output. The relationship continues today such that the producer calls on ITAC when new and improved production methods are discovered and help is needed to implement them. Consequently, ITAC engineers have now had more time to tweak the system than they originally had to design it.

“The original project was a major challenge because of the compressed schedule, and because the scope changed a number of times,” Jones said. "It wasn’t easy to coordinate the delivery of all the equipment. But because of our relationship with Rockwell Automation, we were able to take a calculated risk that paid off for us and our client.” 
 

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