While making a quality asphalt product is still paramount for plant automation, in today's information age, plant automation must play other key roles in the overall enterprise in order for producers to be competitive, especially in an industry that has seen much consolidation in the past decade. Plant automation must support real-time management decisions by providing up-to-the-minute company-wide data, accessible from anywhere in the enterprise. It must allow office and IT personnel to control business data in real-time, while allowing operators to concentrate on running plants. It must mold itself to fit the unique business processes of the producer without requiring the custom programming that has stunted the agility of past systems. Yes, plant automation for the asphalt industry has come a long way to be sure. Here's a brief history.
Prior to 1970
Prior to 1970 asphalt plant automation was entirely electromechanical. This meant the controls for the plant were entirely electric and were based on what is known as relay logic.
Early controls were composed of relay switches, which being mechanical, wore out quickly. These switches were very susceptible to heat, dust, moisture and other natural elements, making them unreliable.
The physical size of early controls was very large as compared to today's controls. They were extremely heavy and not portable. Although these machines were cumbersome by today's standards, they did increase productivity by speeding up the mixing/loading process.
With the advent of transistor and integrated circuit technology, controls became electronic instead of electric in this period.
Physically, integrated circuits were much smaller than relay switches. The integrated circuits were also faster, but the biggest advantage was their reliability. They used no moving parts and were therefore immune to the mechanical (moving) problems encountered with relay switches.
During this time, memory in the controls became economically feasible. Cassette tapes also became a popular choice for memory because of their capability to store information indefinitely. However, the tapes were very susceptible to dust, dirt and moisture.
In 1974, the first microprocessor-based control was installed on an asphalt plant. This year also marked the first time that cassette tapes were bypassed in favor of another type of memory storage: floppy disks. The disks were much faster than tapes but, like tapes, they were susceptible to the environment.
In 1977, a new type of memory was introduced known as EPROM (Erasable Programmable Read Only Memory) and ROM (Read Only Memory). These types of memory were impervious to dust, dirt, heat and even coffee spills. EPROMs were also extremely fast. In this era, control systems also became much smaller and could fit on a tabletop desk. As integrated circuits grew smaller and smaller, this enabled dedicated systems to add more and more capacity without adding to the physical size of the control.
The '80s brought about the personal computer revolution, and in 1984 the first PC was used to control an asphalt plant. Computers were everywhere and the ability to interface the office with the plant was a logical step to eliminate hand-written administrative functions. Prior to building the communication interface between office and plant computers, information generated at the plant had to be re-entered into the office computer. This was often time consuming, expensive, and prone to error.
Background communications to the plants was introduced in 1989. Background means that another task can be occurring and be invisible to the plant operator. More specifically, the plant operator could be running the asphalt plant with all of its requirements and, at the same time, the office could call in and update files, retrieve data, or generate reports. Office tasks became completely invisible to the plant operators and did not interfere with their work.
Multi-tasking environments were also introduced to the industry during this period. This technique allows many tasks to occur virtually simultaneously. For example, operators could mix material in the batch tower, load material out of the silos and access the database files, at the same time and without performance degradation.
Memory constraints became a concern of the past in the early 90's. With the rapid technology advancements in the PC industry, producers could easily store thousands of trucks, customers and products.
Microsoft Windows paved the way for the first graphical user interface (GUI) to be introduced for control of an asphalt plant. The use of animated pictures and "live" graphs to depict real-time trends aided operators in quick problem detection and response.
While RFID (radio frequency identification) technology had been around for some time, the mid-'90s saw the asphalt industry utilize this technology to solve truck management issues. Truck waiting times were monitored (both at the plant as well as at the paving site) and analysis tools helped reduce cycle times and minimize truck usage.
Up to this point, plant-to-office communication had been limited to crude file exchanges in which most systems were merely capable of sending an end-of-day file of tickets back to the office. Some systems could also accept replacements of entire data files from the office. But, in 1997, the first on-line gateway between office and plants was introduced to provide seamless, real-time integration of plant production data with office accounting and management information systems. Multiple plants could all be in sync with the office. Office personnel had the ability to access company-wide production and operational data to manage logistics, answer customer questions, and plan production. Database, transactions and operational data were also accessible from any Microsoft-compatible program — locally or over the network.
The new millennium and beyond
In 2002, the first asphalt automation system with highly configurable software was introduced to the industry. For years, custom requests meant custom programming at the producer's expense. Now, software has been introduced that can be configured to meet the exacting requirements of their users without programmer involvement. Producers have the ability to mold the system to their unique business processes. This includes the ability to add fields, layout printing on delivery tickets, add or modify reports, add special logic, create their own pricing schemes, etc.
Whereas custom software had the effect of locking producers out of new versions, the configurable and modular design of today's software allows users to receive new releases and features, while maintaining the configuration settings that make the software unique for their specific business requirements.
New office software utilizes open database architecture such as ODBC (open database connectivity) to allow seamless integration with virtually any office application. Customer and job changes are automatically broadcast to all plants and transactions are automatically retrieved and invoiced without human intervention.
The technological advancements in automation and plant-to-office integration have brought about many changes to our industry. Thankfully, they have all been integral in helping producers to improve quality, maximize productivity, provide valuable management information and realize greater profits.
Kenneth Cardy is president of Libra Systems Corp., based in Harleysville, PA.
Gaining best-in-class plant throughput
Quickly and economically fulfilling customer demand is a must. New automated ticketing kiosks and silo load out and truck ticketing systems are an outstanding combination that can be used to achieve exceptional productivity improvements. These new automation solutions help operators more efficiently manage points-of-sale and increase capacity without having to assign more plant personnel.
A major materials company was seeking to efficiently manage the truck ticketing process at a large, modern production site, while at the same time automatically capture transaction data without the need for more ticketing personnel. Having multiple points-of-sale at this particular site, the company was searching for the most practical, yet fool-proof solution to manage them all.
The solution used includes:
- Asphalt silo load out — automatically controls load out in scale-under, back-weigh or weigh-batcher configurations; also supports a variety of lane and silo-per-lane configurations.
- Aggregate silo load out — similar configuration options to asphalt load out.
- Unattended kiosk — can be configured with RFID readers, keypads or other input devices; RFID read-only devices are also available.
- Remote printers — various industry printers can be placed on platforms either with kiosks or separately.
This solution is highly configurable, enabling field setup and implementation in a matter of weeks. This customer used BMG Seltec's software and implementation specialists to install multiple applications at this site. The implemented ticketing solution operates in a 'semi-unattended' fashion where the scale clerk's time is shifted to focus on drive-up and cash business, while their regular customers equipped with RF swipe cards move in and out of the quarry very quickly using one of three kiosks at the site.
Since implementing the three separate ticketing kiosks, the company can allow for quicker turnaround in the yard while focusing on more important customer response issues as well as sales management tasks. Sales managers are now assured that their orders are efficiently fulfilled, and that customers will be satisfied with quick and hassle-free service at the site.
The system nearly runs itself, and only rarely does it require human interaction to handle a ticketing transaction at the point-of-sale. Additionally, transactions are automatically sent to upstream systems in near real-time fashion, allowing for immediate operational reporting and accounting to take place.
From a support standpoint, changes to kiosks are easily implemented at any time with simple hardware extensions to the operating software.
Systems Control Centers
Systems control centers are designed specifically for the asphalt industry with an emphasis on rugged construction, operator comfort and logical integration of the plant controls.
- Portable, skiddable or stationary models are available and can optionally be provided with any necessary combination of automation, controls or switchgear
Astec offers the flexibility of Microsoft Windows 2000 and soft PLC engine.
- Run and monitor all plant functions from a standard PC, including blending operations, plant motors, motor currents, mix and plant temperatures, material inventory, silo levels, energy usage and alarm status.
- No traditional control panels needed.
- Flexible Profibus I/O
- Siemens WinCC MMI
- Runs on standard PC under Windows 2000
Dillman Equipment Inc. supplies a full line of comprehensive controls for both batch and continuous mix plants.
- Complete control systems and single control panels are available for any manufacturer's plant
- All control systems can be customized for a new plant or retrofited per specific requirements
- Technical support is offered 24 hours a day for customer service
Libra Enterprise Information Server
The Enterprise Information Server from Libra Systems is designed for plant-to-office integration.
- Changes made by office personnel are automatically sent to the plant computers
- Transactions and plant status are automatcially retrieved from the plants
- Includes user-friendly analysis tools
Stansteel Controls and Control Houses
Stansteel Asphalt Plant Products control houses feature proven PC-based technology for ease in equipment changes and updates.
- Automatic controls help the operator administer plant activities more efficiently for greater production
- Air pollution system controls
- Batch plant controls
- Cold feed system controls
- Custom control panels
- Drum mixer plant controls
- Loadout controls
- Rotary mixer controls
- Total plant control system with ACCU-TRACK
MPAQ TouchBatch Asphalt
Automation for asphalt batch, cold feed and silo loadout is now available in the new TouchBatch technology from MPAQ Automation.
- Just one MPAQ computer is needed to automate the cold feed section, the batch plant and the silo load-out
- With the batch module, the operator can quickly load each truck or replenish the silo storage
- The cold feed module controls the aggregates' flow rate according to mix design specifications
- The silo loadout module loads trucks with automatic free-fall compensation times which the gates to avoid overloading the truck
CTI Asphalt Plant Control Systems
CTI Controls Technology Inc. offer a variety of plant controls for batch plants, continuous mix plants and loadout.
- System offers reliability, flexibility and fast service response
- Free telephone technical support
Reliable Asphalt Products offers a complete line of controls for the hotmix asphalt industry.
- For both batch and drum type plants
- Single control panels to complete plant packages including control house available
- All systems have been specifically designed for accurate, dependable performance in harsh environments
- Electrical control services and trouble shooting on a 24 hour/seven day a week basis for any type of control system
JWS Apex 2 Loadout System
Version 2 of the Apex Loadout system from JWS Corp. integrates with its Apex Ticketing module to load and ticket trucks from overhead bins or silos.
- Includes software and control panel
- Can be installed with new plants or retrofitted to existing units
- Operates on standard Windows 2000/XP PC
- Three available weighing methods
BMG Seltec Unattended Kiosks
BMG Seltec introduces a new family of unattended kiosk products that automatically identify trucks as they enter the yard.
- Can be configured to allow drivers to easily select the customer, job, destination and product for reduced data entry time and potential keying errors
- In-yard (gate-to-gate) times are automatically tracked for performance monitoring
- Uses an RFID proximity card reader for reliable identification in adverse environments
- Optional Laser Light LED message boards can direct trucks to proper loading destinations
- Tickets can be printed remotely so that drivers never need to leave their trucks