Vulcan Materials Company -- one of the nation’s largest producers of construction aggregates and a major producer of aggregates-based construction materials, including asphalt and ready-mix concrete -- has 342 sites that produce construction aggregates, and about 100 facilities that produce asphalt and/or concrete.
The company has been serving the San Antonio, TX, area for 30-plus years.
“We operate 13 HMA plants in Texas,” says Justin Stumberg, asphalt production division manager. “We have two asphalt production sites serving the Greater San Antonio area. The Helotes, TX, location has two Gencor asphalt plants – a 500-tph model and a three-year-old 400-tph plant.
“The other location, known as 1604 because of the beltway that encompasses San Antonio, also has Gencor plants -- a 400-tph asphalt plant and the new 2016 Gencor 400-tph plant,” he says.
Vulcan’s newest plant in San Antonio – a 2016 Gencor Ultraplant at the 1604 location -- is designed to increase capacity and service more customers.
“We now have two locations with two plants,” says Stumberg. “This allows us to serve our customers with excellent availability, 24/7 on many occasions.”
Latest addition
The new 400-tph Ultraplant at the 1604 location is built with patented counterflow Ultradrum technology. The A.R.E. concept uses the gases and convective heat of the combustion zone to preheat and advance the release of internal moisture in the recycle pavement.
This advanced release of moisture results in higher production due to a more even and staged release of water vapor in the drying process using less energy by not super-heating the virgin aggregates.
Other components of the new plant include:
- Nine 10 x 14 cold feed bins with direct-drive VFD (variable frequency drive) toughing feeders
- Two 10 x 15 RAP bins with direct-drive VFD toughing feeders
- One 8 x 14 RAS bin with direct-drive VFD toughing feeder equipped with a weigh scale
- 89,000-cfm Ultraflo baghouse with VFD fan drives
- 135 million BTU Ultraflame II Burner with servo motors for ultimate control of burner fuel/air controlled by a Vector burner control; the servo motors replace commonly used linkage to position the burner firing rate
- Gencor Ultrafoam warm mix system
- Three 200-ton Gencor storage silos over two truck scales
- Stationary Gencor control center with Ultralogiks blending and operations control, Allen-Bradley PLCs and motor control center
Recycled materials
Vulcan Materials prides itself with accommodating complicated mix designs as well as traditional TXDOT mixes.
“We have had many opportunities to test and produce new and challenging mixes,” says Stumberg. “We serve TXDOT jobs along with commercial and municipal projects.”
Vulcan’s 1604 location processes its own RAP onsite and uses Gencor Ultradrums with advanced recycle entry. “These drums have allowed us to use recycle with little to no effect to workability of the mix,” Stumberg explains.
The 9' 9" x 50' Ultradrum and Advanced RAP Entry are designed for producing maximum percentages of RAP/RAS mix designs while being able operate efficiently with high percentages of moisture in the RAP/RAS, says Stumberg.
With the Gencor dual recycle collar system, RAP and RAS is separated into two entry collars. The RAP enters the first “uphill” collar and the RAS with dust return into the second “downhill” collar. This allows for the RAS to become lubricated with the dust to reduce recycle build up in the drum.
“The largest benefit is that the RAP and RAS are weighed individually on two separate belts,” says Stumberg. “This allows for much more precise control of metering the recycled binder.
“RAP and RAS have two extremely different mix percentages with two extremely different AC contents,” he continues. “If you were to weigh/meter both products on one belt, you could have a big variance of total AC (recycled and virgin binder) in your hot mix. By separating the two we have complete control of the exact recycled AC binder we are adding to the mix. This results in a very consistent workable mix.”
The 1604 facility also opted to add VFDs (variable frequency drives) to the drum. The drum is driven by four 50-hp VFD drives which enable efficient control of the drying/mixing time over a variety of operating conditions.
“We are still experimenting with RPMs to optimize efficiencies with higher or lower percentages with recycle, higher moistures and open/dense graded mixes,” says Stumberg. “So far our results have been very exciting. We have noticed by changing RPMs on some mix designs we are able to obtain more BTUs in the material and lowering or raising the baghouse inlet temperatures when desired.”
Advanced controls
The new plant is also outfitted with the Ultralogiks plant control system, a totally integrated automation package that manages and monitors all plant control functions with a windows-based environment and graphical user interface.
“This is the most up-to-date and, in my opinion, the most advanced but operator friendly control system available,” says Stumberg.
This system allows for optimum blending automation and updates data of plant in real time. “We can see every little thing happening with the plant in real time,” he says. “This allows for excellent preventive maintenance data because the system shows accurate digital motor amperages and limit statues/position at all times.”
The hardware is an advanced Allen-Bradley PLC control platform that performs all the plant operations, including both blending and loadout functions. A backup computer and redundant hard drive assure complete security of the data and operating system in the event of a failure of the PLC.
“The multiple monitors allow for ease of operation with maximum data,” says Stumberg. “The system is also very easy for new operators to learn.”
The Ultralogiks main operating screens display a logical presentation of operating data through the use of segregated screen sections. The upper section displays items at the point of liquid asphalt injection; the center section offers selectable views of Motors, Maintenance, or Event Log information as well as configuration settings and calibration screens. Detailed user screens for each equipment component are displayed by simply clicking on the equipment image.
The bottom line: Customer service
While it’s an important aspect, having the latest and greatest equipment is just part of offering excellent customer service. Your mix design, plants and people all need to be consistent and part of the customer service solution, says Stumberg.
“Customer service is of the utmost importance to me and Vulcan Materials,” he says.” Meeting our customers demand with a quality product that both of us can highly appreciate is our priority.
“We also consider ourselves to be good stewards in the industry,” he says. “We care about providing an excellent product that builds good roads and parking lots.”
Their people are what really make Vulcan, says Stumberg, and are the key to customer service success. Vulcan values its employee development and works hard to create safety, training, and mentoring programs for its workers.
“Our number one asset is our people,” he concludes. “We put a lot of effort into our programs to ensure that.”
